Evaluation of femoral neck fracture migration after internal fixation with an angle stable implant compared with gold standard cannulated cancellous screws in young adults: Study protocol for a clinical RCT using radiostereometric analysis

Evaluation of femoral neck fracture migration after internal fixation with an angle stable implant compared with gold standard cannulated cancellous screws in young adults: Study protocol for a clinical RCT using radiostereometric analysis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Evaluation of femoral neck fracture migration after internal fixation with an angle stable implant compared with gold standard cannulated cancellous screws in young adults: Study protocol for a clinical RCT using radiostereometric analysis Michaela Manalili Hansen, Emil Toft Petersen, Per Hviid Gundtoft, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5433232/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 07 Feb, 2026 Read the published version in Trials → Version 1 posted 6 You are reading this latest preprint version Abstract Background Hip fractures are most commonly suffered by elderly patients, but 2–11% of hip fractures affect younger patients. In young adults with femoral neck fractures, internal fixation is the recommended treatment for both displaced and non-displaced fractures. However, treatment with internal fixation carries a high complication rate. A known complication of internal fixation after gold standard cannulated cancellous screws is fracture compression resulting in shortening of the femoral neck, which is associated with clinically important decreases in functional outcome. New osteosynthesis implants have been developed to prevent fracture compression and improve the outcomes of internal fixation of femoral neck fractures. Recent preliminary clinical and biomechanical studies show that implants with interlocking screws and/or angle stability have promising results compared to standard internal fixation with cannulated cancellous screws. Measurement and comparison of three-dimensional fracture displacement requires precise method, which may be accommodated with CT bone models and weight-bearing radiostereometric imaging in the months after surgery. Methods A total of 54 young adults under 65 years of age with femoral neck fractures will be electronically randomised to treatment with either internal fixation with cannulated cancellous screws (gold standard) or an angle stable implant (Dynaloc, Swemac). Patients will be excluded if they are unable to understand the study information, have a transcervical, basicervical or pathological fracture, or present clinically as frail. Primary outcome measure is fracture migration at 12 weeks measured in radiostereometric imaging using CT bone models and AutoRSA software. Secondary outcomes will be fracture migration in terms of femoral neck shortening at 6 weeks, function scores and pain Verbal Rating Scale at 6 and 12 weeks, surgical complications, reoperation, and mortality at event. Discussion This clinical trial will examine fracture migration and the functional outcomes of internally fixated femoral neck fractures in young adults by comparing the results of an angle stable implant (Dynaloc, Swemac) compared with cannulated cancellous screws. The study has perspective to provide scientific evidence for empirical decision-making when choosing implants for femoral neck fractures in young adults. Trial registration ClinicalTrials.gov ID: NCT06521671. Registered July 22nd 2024 Clinical outcome randomised controlled trial femoral neck fracture internal fixation fracture migration radiostereometric analysis Figures Figure 1 Figure 2 Administrative Information Note: the numbers in curly brackets in this protocol refer to SPIRIT checklist item numbers. The order of the items has been modified to group similar items (see http://www.equator-network.org/reporting-guidelines/spirit-2013-statement-defining-standard-protocol-items-for-clinical-trials/ ). Table a: Administrative information Title {1} Evaluation of femoral neck fracture migration after internal fixation with an angle stable implant compared with gold standard cannulated cancellous screws in young adults: Study protocol for a clinical RCT using radiostereometric analysis Trial registration {2a and 2b}. ClinicalTrials.gov ID: NCT06521671 First registered on July 22nd 2024 Protocol version {3} Protocol version 1.5 Funding {4} This study is part of a PhD project supported by the fund to support clinical doctoral candidates in the Region of Southern Denmark and supported by the implant company Swemac Innovation AB. Author details {5a} Michaela Manalili Hansen, MD 1,2 Emil Toft Petersen, MSc, PhD, Assistant Professor 3,4 Per Hviid Gundtoft, MD, PhD, Associate Professor 3,4 Janni Jensen, MSc, PhD, Associate Professor 5,6 Maiken Stilling, MD, PhD, Clinical Professor 3,4 Ming Ding, MD, PhD, DMSci, Professor 1,2 Bjarke Viberg, MD, PhD, Clinical Professor 1,2 1. Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark 2. Department of Clinical Medicine, University of Southern Denmark, Denmark 3. Department of Orthopaedic Surgery and traumatology, Aarhus University Hospital, Denmark 4. Department of Clinical Medicine, Aarhus University, Denmark 5. Department of Radiology, Odense University Hospital, Denmark 6. Research and Innovation Unit of Radiology, University of Southern Denmark, Denmark Name and contact information for the trial sponsor {5b} Bjarke Viberg, MD, PhD, Professor Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark [email protected] Telephone: +45 28669059 Role of sponsor {5c} Sponsor is the initiator of the study and has a role in the study design, management and reporting of the study. Positive, negative and inconclusive results will be published by the author group of which the sponsor is a part of, but does not have ultimate authority over. Introduction Background and rationale {6a} Hip fractures are most commonly suffered by elderly patients, but 2-11% of hip fractures affect younger and middle-aged patients [1-4]. A large portion of the young adults with hip fractures is speculated to be frail, but younger adults with femoral neck fractures (FNF) might face higher demands for their functional outcomes post-treatment, as this patient group is often still active in the workforce [2]. The choice of treatment must take the patient’s overall level of fitness and frailty into consideration [2, 5]. FNF are a specific type of intracapsular hip fracture with the recommended treatment being internal fixation regardless of displacement [6, 7]. Internal fixation is preferred in patients under 60 years of age, as it preserves the native hip joint and is less invasive than prosthetic surgery [6, 8, 9]. A meta-analysis reported an 18% reoperation rate in younger patients [10] and the failure rate following displaced FNF can be as high as 59% [2]. One of the known complications of internal fixation is shortening of the femoral neck due to dynamic compression of the fracture during axial loading [11, 12]. Shortening of the femoral neck is associated with clinically important decreases in functional outcome [13]. The associated hip pain, osteonecrosis, non-union and impaired hip function, can ultimately lead to reoperation [13-16]. More stability in the internal fixation could reduce the degree of femoral neck shortening and complications. New osteosynthesis implants for FNF have therefore been developed with focus on improved strength as well as multi-directional and torsional stability compared to standard internal fixation with cannulated cancellous screws (CCS). Studies demonstrate superiority of the newer angle stable implants in biomechanical studies, clinical studies using electronical overlapping of images, and in a meta-analysis [17-22]. The clinical Randomised Controlled Trials (RCT) with the newer angle stable implants use standard x-ray AP views to measure lateral protuberance of the internal fixation implant or electronical overlapping of images to assess femoral neck shortening [12, 13, 17]. A more precise measurement of femoral neck shortening is to perform sequential radiostereometric analysis (RSA) [23-26]. RSA has a high precision and accuracy and has been used increasingly to assess three-dimensional measurements of orthopaedic implants as the high precision allows for small-scale studies to be performed [27, 28]. Using the RSA technique will allow for precise evaluation of fracture migration when comparing a newer angle stable implant with the standard internal fixation [28]. Objectives {7} The objective is to assess an angle stable implant (Dynaloc, Swemac) for internal fixation of FNF and compare it to the gold standard treatment with CCS using fracture migration as the primary outcome. Trial design {8} The study is designed as a single-blinded RCT with RSA using parallel groups of equal size, including all adults with an FNF under the age of 65 and a Clinical Frailty Scale [29] up to and including four. Methods: Participants, interventions and outcomes Study setting {9} Patients will be recruited from Odense University Hospital, Denmark and Aarhus University Hospital, Denmark. The sites are expected to start recruitment from April 2025. Recruitment is expected to be completed in 2027. 54 patients will be equally randomised to surgical treatment with either an angle stable implant (Dynaloc, Swemac) or CCS. The trial flow and participant timeline are outlined in table 1 and figure 2. Eligibility criteria {10} All adults under 65 years of age with a FNF (ICD-10 coding DS720) will be screened for eligibility using a prefabricated screening form. The inclusion criteria are: Femoral neck fracture Age 18-64 years Ability to speak and read Danish Willingness to participate The exclusion criteria are: Pathological, basicervical or transcervical fracture Clinical Frailty Scale ≥5, indicating mild to severe frailty prior to the fracture [29] Cognitive impairment that hinders informed consent Previous fracture in the ipsilateral femur Comorbidities making the participant ineligible for internal fixation Who will take informed consent? {26a} Informed consent will be retrieved by a physician before randomisation and undergoing the allocated treatment. All patients with FNF are recruited in the emergency department or in the ward prior to surgery. A healthcare professional will inform the patient about the trial. The patient will be given information verbally as well as written participant information in an undisturbed room. Next of kin will be invited to attend by phone if requested by the participant, if there are no next of kin present in person with the patient in the emergency department. An impartial assessor can be assigned, if no next of kin is available. As surgery of FNF is required to take place as quickly as possible due to a higher risk of mortality when surgery is delayed, only a short reflection time of two hours is permitted. Additional consent provisions for collection and use of participant data and biological specimens {26b} N/A: The study participants give consent to all outcomes including exploratory outcomes (see {26a}) Interventions Explanation for the choice of comparators {6b} The investigational device, the Dynaloc implant, will be compared to internal fixation with CCS as the latter is considered the gold standard treatment for internal fixation of FNF in young adults [6, 7, 30]. Clinical trials have been conducted on the elderly population assessing an earlier version of the Dynaloc implant and a similar implant, Pinloc [31, 32]. As these trials have been conducted on the elderly, who are now treated more frequently with arthroplasty [33, 34], the knowledge and results from previous trials do not apply to the patient group consisting of young adults under 65 years of age. Intervention description {11a} Patients will be randomised to internal fixation with three CCS or an angle stable implant designed to minimise fracture migration (Dynaloc, Swemac). Both Dynaloc and CCS are CE-marked medical devices and will be used as recommended by the manufacturer. The Dynaloc System consists of the combination of a plate and three screws as shown in Figure 1. Dynaloc is a class IIb device intended for temporary stabilisation of FNF in adults. The operation procedures will be according to the manufacturer's surgical technique/instructions for use. A CT-scan will be performed preoperatively to segment bone models for RSA. Patients will be subject to non-weight-bearing radiostereometric imaging at baseline. The patients will be followed with non-weight-bearing and weight-bearing radiostereometric imaging for assessment of fracture migration at 6 weeks, 12 weeks and 12 months and standard x-ray at 12 months. At all follow-ups, function scores will be evaluated. After discharge, all patients will be referred to standard rehabilitation with weight-bearing as tolerated. [Figure 1] Criteria for discontinuing or modifying allocated interventions {11b} If the operating surgeon deems it necessary to convert to prosthetic surgery after allocation of the intervention, the allocated intervention can be waived, and the patient will be excluded from the study. A reason for conversion to prosthetic surgery after allocation of the intervention could be an irreducible fracture. Strategies to improve adherence to interventions {11c} N/A : The intervention is a one-time surgery and once the surgery has been performed, there is no need for subsequent adherence to the intervention. Relevant concomitant care permitted or prohibited during the trial {11d} N/A : The patients will follow standard postoperative care and all medical interventions needed for concomitant diseases are permitted. Provisions for post-trial care {30} Study participants follow the standard post-trial care for patients with FNF. Participants who experience harm due to this trial will through the independent Danish Patient Compensation Association have the same care as all other patients in Denmark. Outcomes {12} The primary outcome measure is non-weight-bearing fracture migration in terms of femoral neck shortening as measured in a supine RSA set-up at 12 weeks using CT based bone models and AutoRSA software (AutoRSA Research Group, Aarhus, Denmark). Secondary outcomes will be fracture migration (multi-directional) at 6 weeks, function scores (New Mobility Score [35] and modified Harris Hip Score [36]), health-related Quality of Life (EQ-5D-5L) [37], pain Verbal Rating Scale [38], mortality, reoperations, and complications at 6 and 12 weeks. Exploratory outcomes will be the same as primary and secondary outcomes at 12 months, function scores at 6 months and implant migration and inducible fracture migration (comparison between non-weight-bearing and weight-bearing RSA in a standing set-up) at 6 weeks, 12 weeks and 12 months. The outcomes have been selected to include measures of body structures and function, limitations to activities, and limitations to participation as well as mortality [39, 40]. Participant timeline {13} Table 1: Participant timeline. Enrolment Allocation Post-allocation TIMEPOINT -t 1 0 Admission 6 weeks 12 weeks 6 months 12 months At event ENROLMENT Eligibility screen X Informed consent X Allocation X INTERVENTIONS Surgery X ASSESSMENTS X-ray X X CT scan X (pre-op) Radiostereometric imaging X (post-op) X X X New mobility score X X X X X Modified Harris Hip Score X X X X X EQ-5D-5L X X X X X Pain Verbal Rating Scale X X X X X Reoperation X Complication X Death X Pre-op, before operation; Post-op, after operation; EQ-5D-5L, EuroQol 5 domain [Figure 2] Sample size {14} Primary outcome is shortening of the femoral neck at 12 weeks. A clinical relevance can be expected at >5mm shortening of the femoral neck [41]. Femoral neck shortening in the group randomised to internal fixation with CCS is expected to be 5.3mm (SD 4.5mm) at 6 weeks according to Van Embden et. al. [23] and we do not expect further shortening of the femoral neck between 6 and 12 weeks. Using power 0.9, significance level 0.05, and expecting femoral neck shortening of maximum 1 mm for the angle stable implant (Dynaloc) compared with 5.3mm (SD 4.5mm) [23] using three CCS a total sample size of N=50 can be calculated, N=25/group in this equality study design. We expect approximately 10% loss to follow-up and will therefore include a total of 54 patients. Recruitment {15} The study will include patients from two hospitals in Denmark. The physician on call is responsible for including patients. A ll eligible patients will be screened at admission and asked to participate in the study. Patients will be recruited in the emergency department or in the ward prior to surgery. Assignment of interventions: allocation Sequence generation {16a} If informed consent is provided, eligible patients can be enrolled in the study. Patients will be entered into an electronic database (REDCap [42, 43]) and randomised to either CCS or Dynaloc using blocks of n=4 and n=6 and will be stratified based on the Garden classification (Garden 1-2 or 3-4) [44] to account for fracture displacement and stratified based on hospital of admission. The patients will be stratified according to the Garden classification as studies show significantly higher failure rates in Garden type 3 and 4 [45, 46] . Concealment mechanism {16b} The operating surgeon will contact a central coordinator, who performs the randomisation using REDCap [42, 43], prior to the surgery. Therefore, the surgeon knows which implant to use before entering the operating theatre. Implementation {16c} The randomisation and allocation will be performed by a central coordinator using REDCap [42, 43] 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. The admitting physician will enrol participants and the operating surgeon will implement the assigned intervention. Assignment of interventions: Blinding Who will be blinded {17a} The implant and outcome will be blinded to trial participants and care providers. A standard phrase for the surgery will be used. Procedure for unblinding if needed {17b} According to standards of care and journal publication requirements, the project staff can reveal the true surgery in case of severe pain or complications; otherwise, patients will be blinded until the end of the trial. Data collection and management Plans for assessment and collection of outcomes {18a} Project staff will collect data, perform CT and RSA examinations and RSA analysis. Screening will be performed by the admitting doctor. Baseline data will be collected during admission and will be entered directly into REDcap by project personnel. Questionnaires will be sent directly to the patients using REDcap, and the answers will be automatically uploaded into REDcap. At the scheduled follow-ups, project personnel will see the patients in the outpatient clinic and check that the electronic questionnaires have been completed. The project personnel will obtain any missing information during the scheduled follow-ups and data will be entered directly into REDCap. Radiostereometric analysis RSA is a precise radiological method using two simultaneously obtained x-rays to measure migration of bone and implant models over time. It has classically been used to measure fixation of hip and knee arthroplasty but has also been used to measure fracture healing and displacement of intertrochanteric hip fractures [24] . All patients will be subjected to a pre-operative CT scan of the hip/pelvis region for generating bone models (hip, pelvis and femur) to be used in the analyses of fracture migration over time (static RSA, non-weight-bearing recordings) and in the analyses of exploratory outcomes: Implant (screw) migration in the femoral head (static RSA, non-WB recordings) and inducible fracture migration (non-weight-bearing RSA recordings vs. weight-bearing RSA recordings at 6 weeks, 12 weeks and 12 months). The patients will be mobilised prior to baseline RSA. A check-off form has been designed for evaluating the degree of mobilisation (loading) during hospitalisation, to make sure the degree of mobilisation (loading) prior to baseline RSA is known. The check-off form includes different degrees of mobilisation from mobilisation to chair, standing with 50% load, >5m walking, >10m walking to free mobilisation. The need for walking aids and which type of walking aid used during mobilisation will also be registered. To ensure a load of 50% ± 10% bodyweight during weight-bearing RSA recordings at follow-up a scale will be used, and the load will be registered on the X-ray. All bone models will be standardised with reference coordinate systems in order to estimate model migrations/movement and determine fracture healing and implant fixation. At 6 week follow-up double examination RSA recordings will be performed in order to validate the precision of the fracture migration measurements [28] . AutoRSA software (in-house) will be used by project personnel for analyses of RSA recordings utilising CT bone models and surface models of the implant. Plans to promote participant retention and complete follow-up {18b} Participants will be given extra follow-up appointments compared to the standard treatment plan for patients with internally fixated FNF. If the patients do not attend follow-up appointments, they will be contacted directly and invited to a new follow-up appointment promoting retention. Data management {19} Study data will be collected and managed using REDCap electronic data capture tools hosted at OPEN, Region of Southern Denmark [42, 43]. REDCap (Research Electronic Data Capture) is a secure, web-based software platform designed to support data capture for research studies, providing 1) an intuitive interface for validated data capture; 2) audit trails for tracking data manipulation and export procedures; 3) automated export procedures for seamless data downloads to common statistical packages; and 4) procedures for data integration and interoperability with external sources. Data will be entered directly into REDCap and range checks will be applied where possible to ensure data quality. Confidentiality {27} Project data are securely stored in the project’s SharePoint and REDCap database during the active research period. Data will be entered via an encrypted connection which meets current requirements for data security. Data will be marked with identifiers, making it possible to deidentify data for the required storage. Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33} N/A, no biological specimens will be collected. Statistical methods Statistical methods for primary and secondary outcomes {20a} Randomisation groups will be kept blinded during statical analyses. The data distribution will be assessed and data presented accordingly. Continuous data will be analysed using Linear Mixed Model statistics and categorical data will be compared using the χ2 test or the Fisher exact test. A p-value of <0.05 will be considered statistically significant. The postoperative complication rates will be defined as the sum of the individual rates of complications and reoperations. Mortality will be analysed using Cox-regression. Computerised statistical software packages (STATA 18, StataCorp) will be used for analyses and graphical presentation. Interim analyses {21b} Due to the relatively small sample size of the study, interim analysis is not planned. The coordinating investigator will monitor data closely during the study period. In the event of unforeseen complications in one or both study groups, the entire author group will be consulted, and the need for terminating the study will be discussed and decided in the author group (expert panel). Methods for additional analyses (e.g. subgroup analyses) {20b} N/A : N o additional/subgroup analyses are planned. Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c} If a participant’s follow-up is discontinued, the participant will be omitted from a per-protocol analysis, but will be included in the intention-to-treat analysis. The reason for discontinuation will be recorded in REDCap. If patients’ baseline data and follow-up at 12 weeks have been recorded, the patient will be included in the statistical analysis through multiple imputation. The patient will otherwise be replaced to meet the calculated sample size. Plans to give access to the full protocol, participant level-data and statistical code {31c} The full protocol is registered in ClinicalTrials.gov and will be updated if the protocol is amended. Participant level data will not be made public, as data such as scans and radiostereometric imaging cannot be fully anonymised. Oversight and monitoring Composition of the coordinating centre and trial steering committee {5d} The author group functions as the trial steering committee and the data monitoring committee due to a relatively small sample size in this RCT and consists of the coordinating/principal investigator at Odense University Hospital , the principal investigator at Aarhus University Hospital , the sponsor, two experts in RSA from Aarhus University Hospital and an expert in RSA from Odense University Hospital . The coordinating investigator will monitor the trial, recruitment, and data on an ongoing basis and be responsible for the day-to-day running of the trial in collaboration with the principal investigator at Aarhus University Hospital and the sponsor. The entire group will meet biannually or as needed, depending on the trials phase. The principal investigators and the sponsor will meet weekly during the first months of inclusion, and thereafter monthly. Additional meetings will be held as necessary. Composition of the data monitoring committee, its role and reporting structure {21a} N/A : P lease see above (5d) Adverse event reporting and harms {22} Any unforeseen complications that occur during the trial will be registered in the project’s REDCap database. All Adverse Events, Adverse Device Effects and Near-incidents will be registered. Serious Adverse Events, Serious Adverse Device Effects and Unanticipated Serious Adverse Device Effects will be registered and reported to sponsor immediately. The sponsor will report to the Danish Medicines Agency according to MDCG 2020-10/2 ”Safety reporting in clinical investigations of medical devices under the Regulation (EU) 2017/745” [47]. All Serious Adverse Device Effects will be reported immediately and no later than 7 calendar days from the date the sponsor is made aware. All Serious Adverse Device Effects which indicate an immediate risk of death, serious injury, or serious illness will be reported immediately and no later than 2 calendar days from the date the sponsor is made aware. Frequency and plans for auditing trial conduct {23} X-ray images will be audited the day after admission by an orthopaedic surgeon and a radiologist independent from the primary investigators and sponsor. The primary investigators at each site will monitor the study. The electronic Case Report Forms in REDCap will weekly be monitored centrally by the coordinating investigator and will have an audit-trail. The coordinating investigator will continuously have an overview of the incoming data in REDCap and can thus discover trends, deviations in the study or differences between data. Plans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees) {25} Any modifications or protocol amendments will be registered on ClinicalTrials.gov and the primary investigators of each site will be notified. Dissemination plans {31a} The results will be published in an internationally peer-reviewed journal. Positive, negative and inconclusive results will be published. The protocol is registered in Clinical Trials in accordance with CONSORT guidelines [48]. Trial participants will be informed of the trial results in a layman’s summary. Discussion This is the first clinical RCT investigating the Dynaloc implant using RSA to evaluate fracture migration. The findings from this RCT can help evidence-based decision-making in a clinical setting when choosing surgical treatment for a FNF in young adults. Using RSA to evaluate the primary outcome, only a relatively small sample size is needed due to the high precision of the method [27]. An 8% dropout rate has been accounted for in the sample size calculation. Another strength of the study is the combined evaluation of measures of body structures and function, limitations to activities, and limitations to participation as well as mortality as recommended by the core outcome set for hip fracture trials [39, 40]. Defining the young adults as under 65 years of age is commonly used in research, and a cut-off point of 65 years of age was therefore chosen by the authors [49, 50]. Since this is just below the retirement age in Denmark, the cut-off point of 65 years can provide a homogenous group of participants, still employed at the time of inclusion, with a higher demand for postoperative function, compared to the elderly. A clinical frailty scale of up to and including 4 was chosen to ensure that the study participants are independent and, therefore, likely to have a higher demand for postoperative clinical and functional outcomes [2, 29]. Recruitment of 54 young adults with FNF that are eligible for inclusion may take time, as the incidence of FNF in young adults is low, which is why inclusion will take place at two hospitals. To prevent bias, the randomisation will be using blocks of 4 and 6 and will be stratified by study site. In conclusion, this study is expected to provide results from a clinical trial on the angle stable implant Dynaloc, evaluating both fracture migration and functional outcomes in young adults with FNF. Trial status Protocol version 1.5 Author: MMH The trial was registered on 22/07/2024 in ClinicalTrials.gov (NCT06521671). Status: Recruitment is anticipated to start 01/04/2025 and is expected to conclude in 2027 Abbreviations CCS Cannulated cancellous screws EQ-5D-5L EuroQol 5 domain FNF Femoral neck fracture RCT Randomised controlled trial RSA Radiostereometric analysis Declarations Acknowledgements The study has generously received financial support from the fund to support clinical doctoral candidates in the Region of Southern Denmark (Region Syddanmarks Ph.d.-pulje) and Swemac Innovation AB. Authors’ contributions {31b} MMH is the principal Investigator at Odense University Hospital and the coordinating Investigator; she led the protocol development in close collaboration with the last author, BV. PHG is the principal investigator at Aarhus University Hospital and contributed to the development of the study protocol. ETP and MS both contributed to the study design and the protocol development. They are the lead methodologists regarding RSA research. MD contributed to the study design and the protocol development. BV is the Sponsor and initiator of the study. Contributed to all phases of the study protocol development. All authors read and approved the final manuscript. Funding {4} This study is part of a PhD project supported by the fund to support clinical doctoral candidates in the Region of Southern Denmark and Swemac Innovation AB. The funding is administered by the Orthopaedic Research Department at Odense University Hospital. The Region of Southern Denmark and Swemac Innovation AB do not intend to claim any raw data or influence over results from the study. Current and future funders have no role in design, execution, results or publication of the study. Swemac Innovation AB will receive written annual status updates from the project in terms of recruitment status as well as aggregated data for use in the company’s regulatory purposes. Availability of data and materials {29} Patient information will be secured in a REDCap database [42, 43]. Access will be limited to the current trial workers, and will be limited to data entry only. The primary investigator will keep a list of trial worker with access to the database. The principal investigators and the sponsor will have access to the full final dataset. Swemac Innovation AB will receive aggregated anonymised data for use in the company’s regulatory purposes. Ethics approval and consent to participate {24} The trial will conform to the Declaration of Helsinki’s ethical principles [51]. Permission to conduct the study has been granted from The Danish National Medical Research Ethics Committee (ref. no. 2401073) and the participating Departments of Orthopaedic Surgery at Odense University Hospital and Aarhus University Hospital. The data protection regulation and the data protection act are complied with. By participating in the study, the patients will be subjected to a maximum of 10 mSv with the additional x-ray images and CT scan for AutoRSA, increasing the risk of inducing an incurable cancer due to radiation by 0.05% [52]. Written, informed consent to participate will be obtained from all participants. Participants are covered by the insurance policies of ordinary treatment. Consent for publication {32} The informed consent form and the written patient information sheet has been approved by The Danish National Medical Research Ethics Committee and is available upon request. Competing interests {28} The authors declare that they have no competing interests. References Pasoto, S.G., et al., Osteoporotic hip fractures in non-elderly patients: relevance of associated co-morbidities. Rheumatol Int, 2012. 32(10): p. 3149-53. Rogmark, C., et al., Hip fractures in the non-elderly-Who, why and whither? Injury, 2018. 49(8): p. 1445-1450. Wang, M.T., et al., Hip fractures in young adults: a retrospective cross-sectional study of characteristics, injury mechanism, risk factors, complications and follow-up. Arch Osteoporos, 2017. 12(1): p. 46. Zuckerman, J.D., Hip fracture. N Engl J Med, 1996. 334(23): p. 1519-25. Bartels, S., et al., High failure rate after internal fixation and beneficial outcome after arthroplasty in treatment of displaced femoral neck fractures in patients between 55 and 70 years. Acta Orthop, 2018. 89(1): p. 53-58. Bhandari, M. and M. Swiontkowski, Management of Acute Hip Fracture. N Engl J Med, 2017. 377(21): p. 2053-2062. Ly, T.V. and M.F. Swiontkowski, Management of femoral neck fractures in young adults. Indian J Orthop, 2008. 42(1): p. 3-12. Bhandari, M., et al., Operative management of displaced femoral neck fractures in elderly patients. An international survey. J Bone Joint Surg Am, 2005. 87(9): p. 2122-30. Dansk-Ortopædisk-Selskab, Referenceprogram for patienter med hoftebrud. 2008. p. p. 128 Slobogean, G.P., et al., Complications following young femoral neck fractures. Injury, 2015. 46(3): p. 484-91. Zielinski, S.M., et al., Femoral neck shortening after internal fixation of a femoral neck fracture. Orthopedics, 2013. 36(7): p. e849-58. Stockton, D.J., et al., Incidence, Magnitude, and Predictors of Shortening in Young Femoral Neck Fractures. J Orthop Trauma, 2015. 29(9): p. e293-8. Slobogean, G.P., et al., Femoral neck shortening in adult patients under the age of 55 years is associated with worse functional outcomes: Analysis of the prospective multi-center study of hip fracture outcomes in China (SHOC). Injury, 2017. 48(8): p. 1837-1842. Zlowodzki, M., et al., The effect of shortening and varus collapse of the femoral neck on function after fixation of intracapsular fracture of the hip: a multi-centre cohort study. J Bone Joint Surg Br, 2008. 90(11): p. 1487-94. Hamburger, E., et al., Femoral neck shortening as a sequela of internal fixation for femoral neck fractures and its effect on the coronal alignment of the limb: a pilot study. Arch Orthop Trauma Surg, 2024. 144(2): p. 723-729. Stockton, D.J., et al., High rate of reoperation and conversion to total hip arthroplasty after internal fixation of young femoral neck fractures: a population-based study of 796 patients. Acta Orthop, 2019. 90(1): p. 21-25. Wang, Z., et al., Comparison of early complications between the use of a cannulated screw locking plate and multiple cancellous screws in the treatment of displaced intracapsular hip fractures in young adults: a randomized controlled clinical trial. J Orthop Surg Res, 2018. 13(1): p. 201. Wu, Z.F., et al., Efficacy of the femoral neck system in femoral neck fracture treatment in adults: A systematic review and meta-analysis. World J Clin Cases, 2022. 10(31): p. 11454-11465. Yin, H., Z. Pan, and H. Jiang, Is dynamic locking plate(Targon FN) a better choice for treating of intracapsular hip fracture? A meta-analysis. Int J Surg, 2018. 52: p. 30-34. Brattgjerd, J.E., et al., Increased torsional stability by a novel femoral neck locking plate. The role of plate design and pin configuration in a synthetic bone block model. Clin Biomech (Bristol, Avon), 2018. 55: p. 28-35. Brattgjerd, J.E., et al., Interlocked Pins Increase Strength by a Lateral Spread of Load in Femoral Neck Fixation: a Cadaver Study. Acta Chir Orthop Traumatol Cech, 2021. 88(2): p. 144-152. Brattgjerd, J.E., H. Steen, and K. Strømsøe, Increased stability by a novel femoral neck interlocking plate compared to conventional fixation methods. A biomechanical study in synthetic bone. Clin Biomech (Bristol, Avon), 2020. 76: p. 104995. van Embden, D., et al., The stability of fixation of proximal femoral fractures: a radiostereometric analysis. Bone Joint J, 2015. 97-b(3): p. 391-7. Krogh, A.C., et al., No effect of hydroxyapatite-coated sliding hip screw threads on screw migration in the femoral head/neck of pertrochanteric fractures: a randomized controlled trial using radiostereometric analysis. J Orthop Surg Res, 2023. 18(1): p. 686. Finnilä, S., et al., Radiostereometric analysis of the initial stability of internally fixed femoral neck fractures under differential loading. J Orthop Res, 2019. 37(1): p. 239-247. Alm, C.E., et al., No benefit of the trochanteric stabilizing plate on loss of fracture reduction in AO/OTA 31-A2 trochanteric fractures. Bone Jt Open, 2024. 5(1): p. 37-45. Derbyshire, B., R.J. Prescott, and M.L. Porter, Notes on the use and interpretation of radiostereometric analysis. Acta Orthop, 2009. 80(1): p. 124-30. Kaptein, B.L., et al., Guideline for RSA and CT-RSA implant migration measurements: an update of standardizations and recommendations. Acta Orthop, 2024. 95: p. 256-267. Rockwood, K., et al., A global clinical measure of fitness and frailty in elderly people. Cmaj, 2005. 173(5): p. 489-95. Parker, M.J. and K. Gurusamy, Modern methods of treating hip fractures. Disabil Rehabil, 2005. 27(18-19): p. 1045-51. Borris, L., R. Thorninger, and O. Brinkmann, Premature discontinuation of a randomized comparison between a new implant Dynaloc® and cancellous screws for femoral neck fractures: An ethical dilemma. Journal of Traumatology and Clinical Orthopaedics, 2020. Kalland, K., et al., Similar outcome of femoral neck fractures treated with Pinloc or Hansson Pins: 1-year data from a multicenter randomized clinical study on 439 patients. Acta Orthop, 2019. 90(6): p. 542-546. Dolatowski, F.C., et al., Screw Fixation Versus Hemiarthroplasty for Nondisplaced Femoral Neck Fractures in Elderly Patients: A Multicenter Randomized Controlled Trial. JBJS, 2019. 101(2): p. 136-144. Lu, Q., et al., Hemiarthroplasty versus internal fixation in super-aged patients with undisplaced femoral neck fractures: a 5-year follow-up of randomized controlled trial. Archives of Orthopaedic and Trauma Surgery, 2017. 137(1): p. 27-35. Parker, M.J. and C.R. Palmer, A new mobility score for predicting mortality after hip fracture. J Bone Joint Surg Br, 1993. 75(5): p. 797-8. Byrd, J.W. and K.S. Jones, Prospective analysis of hip arthroscopy with 2-year follow-up. Arthroscopy, 2000. 16(6): p. 578-87. Herdman, M., et al., Development and preliminary testing of the new five-level version of EQ-5D (EQ-5D-5L). Qual Life Res, 2011. 20(10): p. 1727-36. Bech, R.D., et al., The Verbal Rating Scale Is Reliable for Assessment of Postoperative Pain in Hip Fracture Patients. Pain Res Treat, 2015. 2015: p. 676212. Bryant, D.M., et al., Selection of outcome measures for patients with hip fracture. J Orthop Trauma, 2009. 23(6): p. 434-41. Haywood, K.L., et al., Developing a core outcome set for hip fracture trials. Bone Joint J, 2014. 96-b(8): p. 1016-23. Felton, J., et al., Femoral Neck Shortening After Hip Fracture Fixation Is Associated With Inferior Hip Function: Results From the FAITH Trial. J Orthop Trauma, 2019. 33(10): p. 487-496. Harris, P.A., et al., The REDCap consortium: Building an international community of software platform partners. J Biomed Inform, 2019. 95: p. 103208. Harris, P.A., et al., Research electronic data capture (REDCap)--a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform, 2009. 42(2): p. 377-81. Garden, R.S., LOW-ANGLE FIXATION IN FRACTURES OF THE FEMORAL NECK. The Journal of Bone & Joint Surgery British Volume, 1961. 43-B(4): p. 647-663. Erivan, R., et al., Results of femoral neck screw fixation in 112 under 65-years-old at a minimum 2 years' follow-up. Orthop Traumatol Surg Res, 2020. 106(7): p. 1425-1431. Sprague, S., et al., Factors Associated With Revision Surgery After Internal Fixation of Hip Fractures. J Orthop Trauma, 2018. 32(5): p. 223-230. Medical-Device-Coordination-Group, MDCG 2020-10/1 Safety reporting in clinical investigations of medical devices under the Regulation (EU) 2017/745. 2020. Cuschieri, S., The CONSORT statement. Saudi J Anaesth, 2019. 13(Suppl 1): p. S27-s30. Lee, A., et al., Predicting life expectancy after geriatric hip fracture: A systematic review. PLoS One, 2021. 16(12): p. e0261279. Lee, S.B., et al., Differences in youngest-old, middle-old, and oldest-old patients who visit the emergency department. Clin Exp Emerg Med, 2018. 5(4): p. 249-255. World Medical Association Declaration of Helsinki. Ethical principles for medical research involving human subjects. Bull World Health Organ, 2001. 79(4): p. 373-4. National-Videnskabsetisk-Komité, Appendiks 2 Retningslinjer om anvendelse af ioniserende stråling i sundhedsvidenskabelige forsøg. 2011. Supplementary Files Additionalfile4SPIRITchecklist.docx Cite Share Download PDF Status: Published Journal Publication published 07 Feb, 2026 Read the published version in Trials → Version 1 posted Editorial decision: Accept 23 Jan, 2026 Reviewers agreed at journal 08 Jul, 2025 Reviewers invited by journal 07 Jul, 2025 Editor invited by journal 03 Mar, 2025 Editor assigned by journal 19 Feb, 2025 First submitted to journal 19 Feb, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5433232","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":481700703,"identity":"ab2b6a7f-9f9e-4758-aff0-a24552a761a0","order_by":0,"name":"Michaela Manalili Hansen","email":"data:image/png;base64,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","orcid":"https://orcid.org/0000-0003-4975-3567","institution":"Odense University Hospital: Odense Universitetshospital","correspondingAuthor":true,"prefix":"","firstName":"Michaela","middleName":"Manalili","lastName":"Hansen","suffix":""},{"id":481700704,"identity":"cbb73053-7cb3-4ff1-9f28-8402211e72a2","order_by":1,"name":"Emil Toft Petersen","email":"","orcid":"","institution":"Aarhus University Hospital: Aarhus Universitetshospital","correspondingAuthor":false,"prefix":"","firstName":"Emil","middleName":"Toft","lastName":"Petersen","suffix":""},{"id":481700705,"identity":"a8204e26-7b1e-4a56-bd81-13f0720bb0b5","order_by":2,"name":"Per Hviid Gundtoft","email":"","orcid":"","institution":"Aarhus University Hospital: Aarhus Universitetshospital","correspondingAuthor":false,"prefix":"","firstName":"Per","middleName":"Hviid","lastName":"Gundtoft","suffix":""},{"id":481700706,"identity":"ade5ea0d-0041-4500-88ca-eeeea4508fac","order_by":3,"name":"Janni Jensen","email":"","orcid":"","institution":"Odense University Hospital: Odense Universitetshospital","correspondingAuthor":false,"prefix":"","firstName":"Janni","middleName":"","lastName":"Jensen","suffix":""},{"id":481700707,"identity":"1f6df462-92b9-414e-8246-6e88bf078c21","order_by":4,"name":"Maiken Stilling","email":"","orcid":"","institution":"Aarhus University Hospital: Aarhus Universitetshospital","correspondingAuthor":false,"prefix":"","firstName":"Maiken","middleName":"","lastName":"Stilling","suffix":""},{"id":481700708,"identity":"f65a6070-b3da-40b2-b204-fa6238bb2847","order_by":5,"name":"Ming Ding","email":"","orcid":"","institution":"Odense University Hospital: Odense Universitetshospital","correspondingAuthor":false,"prefix":"","firstName":"Ming","middleName":"","lastName":"Ding","suffix":""},{"id":481700709,"identity":"32c1dbda-8858-4300-b98f-0efe0e5acc60","order_by":6,"name":"Bjarke Viberg","email":"","orcid":"","institution":"Odense University Hospital: Odense Universitetshospital","correspondingAuthor":false,"prefix":"","firstName":"Bjarke","middleName":"","lastName":"Viberg","suffix":""}],"badges":[],"createdAt":"2024-11-11 15:26:41","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5433232/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5433232/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s13063-026-09497-7","type":"published","date":"2026-02-07T15:57:57+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":86319658,"identity":"8880d764-c9b9-4c3f-94f2-79b869c43367","added_by":"auto","created_at":"2025-07-09 09:27:30","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":350469,"visible":true,"origin":"","legend":"\u003cp\u003eThe assembled Dynaloc implant installed in the femoral neck\u003c/p\u003e","description":"","filename":"Figure1Dynaloc.png","url":"https://assets-eu.researchsquare.com/files/rs-5433232/v1/e7b09823e3ef5906b004f60f.png"},{"id":86319675,"identity":"2736dfb0-0f78-46ed-ac9f-63282c1e36bf","added_by":"auto","created_at":"2025-07-09 09:27:43","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":87331,"visible":true,"origin":"","legend":"\u003cp\u003eCONSORT diagram, flow of participants. CCS, Cannulated cancellous screws\u003c/p\u003e","description":"","filename":"Figure2CONSORTflowdiagram.png","url":"https://assets-eu.researchsquare.com/files/rs-5433232/v1/cacb6b763f4d80d8c7e76c69.png"},{"id":102235134,"identity":"e8163e76-a2e9-4cd0-a0e0-fed50eb9174b","added_by":"auto","created_at":"2026-02-09 16:15:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2108860,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5433232/v1/b1a21bec-80e4-4f65-a4aa-7d4aaf08b8eb.pdf"},{"id":86319652,"identity":"3aef8336-78d2-4a37-b5b7-bf98e938189b","added_by":"auto","created_at":"2025-07-09 09:27:28","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":37671,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile4SPIRITchecklist.docx","url":"https://assets-eu.researchsquare.com/files/rs-5433232/v1/6942a64f4f1f13272649a58a.docx"}],"financialInterests":"","formattedTitle":"Evaluation of femoral neck fracture migration after internal fixation with an angle stable implant compared with gold standard cannulated cancellous screws in young adults: Study protocol for a clinical RCT using radiostereometric analysis","fulltext":[{"header":"Administrative Information","content":"\u003cp\u003eNote: the numbers in curly brackets in this protocol refer to SPIRIT checklist item numbers. The order of the items has been modified to group similar items (see http://www.equator-network.org/reporting-guidelines/spirit-2013-statement-defining-standard-protocol-items-for-clinical-trials/\u003cspan lang=\"EN-GB\"\u003e).\u003c/span\u003e\u003c/p\u003e\u003cp\u003eTable a: Administrative information\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eTitle {1}\u003c/div\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003eEvaluation of femoral neck fracture migration after internal fixation with an angle stable implant compared with gold standard cannulated cancellous screws in young adults: Study protocol for a clinical RCT using radiostereometric analysis\u003c/div\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eTrial registration {2a and 2b}.\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003eClinicalTrials.gov ID: NCT06521671\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003eFirst registered on July 22nd 2024\u003c/div\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eProtocol version {3}\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003eProtocol version 1.5\u003c/div\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eFunding {4}\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003eThis study is part of a PhD project supported by the fund to support clinical doctoral candidates in the Region of Southern Denmark and supported by the implant company Swemac Innovation AB.\u003c/div\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eAuthor details {5a}\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003eMichaela Manalili Hansen, MD\u003csup\u003e1,2\u003c/sup\u003e\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003eEmil Toft Petersen, MSc, PhD, Assistant Professor\u003csup\u003e3,4\u003c/sup\u003e\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003ePer Hviid Gundtoft, MD, PhD, Associate Professor\u003csup\u003e3,4\u003c/sup\u003e\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003eJanni Jensen, MSc, PhD, Associate Professor\u003csup\u003e5,6\u003c/sup\u003e\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003eMaiken Stilling, MD, PhD, Clinical Professor\u003csup\u003e3,4\u003c/sup\u003e\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003eMing Ding, MD, PhD, DMSci, Professor\u003csup\u003e1,2\u003c/sup\u003e\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003eBjarke Viberg, MD, PhD, Clinical Professor\u003csup\u003e1,2\u003c/sup\u003e\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003e1. Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003e2. Department of Clinical Medicine, University of Southern Denmark, Denmark\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003e3. Department of Orthopaedic Surgery and traumatology, Aarhus University Hospital, Denmark\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003e4. Department of Clinical Medicine, Aarhus University, Denmark\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003e5. Department of Radiology, Odense University Hospital, Denmark\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003e6. Research and Innovation Unit of Radiology, University of Southern Denmark, Denmark\u003c/div\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eName and contact information for the trial sponsor {5b}\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003eBjarke Viberg, MD, PhD, Professor\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003eDepartment of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark\u003c/div\u003e\u003cdiv class=\"SimplePara\"\[email protected]\u003c/div\u003e\u003cdiv class=\"SimplePara\"\u003eTelephone: +45 28669059\u003c/div\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eRole of sponsor {5c}\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003eSponsor is the initiator of the study and has a role in the study design, management and reporting of the study. Positive, negative and inconclusive results will be published by the author group of which the sponsor is a part of, but does not have ultimate authority over.\u003c/div\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003cbr/\u003e"},{"header":"Introduction","content":"\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eBackground and rationale {6a}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHip fractures are most commonly suffered by elderly patients, but 2-11% of hip fractures affect younger and middle-aged patients\u0026nbsp;[1-4].\u0026nbsp;A large portion of the young adults with hip fractures is speculated to be frail, but younger adults with femoral neck fractures (FNF) might face higher demands for their functional outcomes post-treatment, as this patient group is often still active in the workforce\u0026nbsp;[2]. The choice of treatment must take the patient\u0026rsquo;s overall level of fitness and frailty into consideration\u0026nbsp;[2, 5].\u003c/p\u003e\n\u003cp\u003eFNF are a specific type of intracapsular hip fracture with\u0026nbsp;the recommended treatment being internal fixation regardless of displacement [6, 7]. Internal fixation is preferred in patients under 60 years of age, as it preserves the native hip joint and is less invasive than prosthetic surgery [6, 8, 9]. A meta-analysis reported an 18% reoperation rate in younger patients [10] and the failure rate following displaced FNF can be as high as 59% [2].\u0026nbsp;One of the known complications of internal fixation is shortening of the femoral neck due to dynamic compression of the fracture during axial loading\u0026nbsp;[11, 12]. Shortening of the femoral neck is associated with clinically important decreases in functional outcome\u0026nbsp;[13]. The associated hip pain, osteonecrosis, non-union and impaired hip function, can ultimately lead to reoperation\u0026nbsp;[13-16].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMore stability in the internal fixation could reduce the degree of femoral neck shortening and complications. New osteosynthesis implants for FNF have therefore been developed with focus on improved strength as well as multi-directional and torsional stability compared to standard internal fixation with cannulated cancellous screws (CCS). Studies demonstrate superiority of the newer angle stable implants in biomechanical studies, clinical studies using electronical overlapping of images, and in a meta-analysis \u0026nbsp;[17-22].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe clinical Randomised Controlled Trials (RCT) with the newer angle stable implants use standard x-ray AP views to measure lateral protuberance of the internal fixation implant or electronical overlapping of images to assess femoral neck shortening [12, 13, 17]. A more precise measurement of femoral neck shortening is to perform sequential radiostereometric analysis (RSA) [23-26]. RSA has a high precision and accuracy and has been used increasingly to assess three-dimensional measurements of orthopaedic implants as the high precision allows for small-scale studies to be performed [27, 28]. Using the RSA technique will allow for precise evaluation of fracture migration when comparing a newer angle stable implant with the standard internal fixation [28].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eObjectives {7}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe objective is to assess an angle stable implant (Dynaloc, Swemac) for internal fixation of FNF and compare it to the gold standard treatment with CCS using fracture migration as the primary outcome.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eTrial design {8}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study is designed as a single-blinded RCT with RSA using parallel groups of equal size, including all adults with an FNF under the age of 65 and a Clinical Frailty Scale [29] up to and including four.\u0026nbsp;\u003c/p\u003e"},{"header":"Methods: Participants, interventions and outcomes","content":"\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eStudy setting {9}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003ePatients will be recruited from Odense University Hospital, Denmark and Aarhus University Hospital, Denmark. The sites are expected to start recruitment from April 2025. Recruitment is expected to be completed in 2027.\u0026nbsp;\u003cbr\u003e\u0026nbsp;54 patients will be equally randomised to surgical treatment with either an angle stable implant (Dynaloc, Swemac) or CCS. The trial flow and participant timeline are outlined in table 1 and figure 2.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eEligibility criteria {10}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eAll adults under 65 years of age with a FNF (ICD-10 coding DS720) will be screened for eligibility using a prefabricated screening form.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eThe inclusion criteria are:\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cspan lang=\"EN-GB\"\u003eFemoral neck fracture\u0026nbsp;\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan lang=\"EN-GB\"\u003eAge 18-64 years\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan lang=\"EN-GB\"\u003eAbility to speak and read Danish\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan lang=\"EN-GB\"\u003eWillingness to participate\u003c/span\u003e\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eThe exclusion criteria are:\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cspan lang=\"EN-GB\"\u003ePathological, basicervical or transcervical fracture\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003eClinical Frailty Scale \u0026ge;5, indicating mild to severe frailty prior to the fracture [29]\u003c/li\u003e\n \u003cli\u003eCognitive impairment that hinders informed consent\u003c/li\u003e\n \u003cli\u003e\u003cspan lang=\"EN-GB\"\u003ePrevious fracture in the ipsilateral femur\u0026nbsp;\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan lang=\"EN-GB\"\u003eComorbidities making the participant ineligible for internal fixation\u003c/span\u003e\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eWho will take informed consent? {26a}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eInformed consent will be retrieved by a physician before randomisation and undergoing the allocated treatment. All patients with FNF are recruited in the emergency department or in the ward prior to surgery. A healthcare professional will inform the patient about the trial. The patient will be given information verbally as well as written participant information in an undisturbed room. Next of kin will be invited to attend by phone if requested by the participant, if there are no next of kin present in person with the patient in the emergency department. An impartial assessor can be assigned, if no next of kin is available. As surgery of FNF is required to take place as quickly as possible due to a higher risk of mortality when surgery is delayed, only a short reflection time of two hours is permitted.\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eAdditional consent provisions for collection and use of participant data and biological specimens {26b}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eN/A: The study participants give consent to all outcomes including exploratory outcomes\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e (see {26a})\u003c/span\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eInterventions\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eExplanation for the choice of comparators {6b}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe investigational device, the Dynaloc implant, will be compared to internal fixation with CCS as the latter is considered the gold standard treatment for internal fixation of FNF in young adults [6, 7, 30]. Clinical trials have been conducted on the elderly population assessing an earlier version of the Dynaloc implant and a similar implant, Pinloc [31, 32]. As these trials have been conducted on the elderly, who are now treated more frequently with arthroplasty [33, 34], the knowledge and results from previous trials do not apply to the patient group consisting of young adults under 65 years of age.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eIntervention description {11a}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003ePatients will be randomised to internal fixation with three CCS or an angle stable implant designed to minimise fracture migration (Dynaloc, Swemac). Both Dynaloc and CCS are CE-marked medical devices and will be used as recommended by the manufacturer. The Dynaloc System consists of the combination of a plate and three screws as shown in Figure 1. Dynaloc is a class IIb device intended for temporary stabilisation of FNF in adults. The operation procedures will be according to the manufacturer\u0026apos;s surgical technique/instructions for use. A CT-scan will be performed preoperatively to segment bone models for RSA. Patients will be subject to non-weight-bearing radiostereometric imaging at baseline. The patients will be followed with non-weight-bearing and weight-bearing radiostereometric imaging for assessment of fracture migration at 6 weeks, 12 weeks and 12 months and standard x-ray at 12 months. At all follow-ups, function scores will be evaluated. After discharge, all patients will be referred to standard rehabilitation with weight-bearing as tolerated.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e[Figure 1]\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eCriteria for discontinuing or modifying allocated interventions {11b}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIf the operating surgeon deems it necessary to convert to prosthetic surgery after allocation of the intervention, the allocated intervention can be waived, and the patient will be excluded from the study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eA reason for conversion to prosthetic surgery after allocation of the intervention could be an irreducible fracture.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eStrategies to improve adherence to interventions {11c}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eN/A\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e:\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e The intervention is a one-time surgery and once the surgery has been performed, there is no need for subsequent adherence to the intervention. \u003c/span\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eRelevant concomitant care permitted or prohibited during the trial {11d}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eN/A\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e:\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e The patients will follow standard postoperative care and all medical interventions needed for concomitant diseases are permitted. \u003c/span\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eProvisions for post-trial care {30}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStudy participants follow the standard post-trial care for patients with FNF. Participants who experience harm due to this trial will through the independent Danish Patient Compensation Association have the same care as all other patients in Denmark.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eOutcomes {12}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe primary outcome measure is non-weight-bearing fracture migration in terms of femoral neck shortening as measured in a supine RSA set-up at 12 weeks using CT based bone models and AutoRSA software (AutoRSA Research Group, Aarhus, Denmark). Secondary outcomes will be fracture migration (multi-directional) at 6 weeks, function scores (New Mobility Score [35] and modified Harris Hip Score [36]), health-related Quality of Life (EQ-5D-5L) [37], pain Verbal Rating Scale [38], mortality, reoperations, and complications at 6 and 12 weeks.\u0026nbsp;\u003cbr\u003e\u0026nbsp;Exploratory outcomes will be the same as primary and secondary outcomes at 12 months, function scores at 6 months and implant migration and inducible fracture migration (comparison between non-weight-bearing and weight-bearing RSA in a standing set-up) at 6 weeks, 12 weeks and 12 months.\u0026nbsp;\u003cbr\u003eThe outcomes have been selected to include measures of body structures and function, limitations to activities, and limitations to participation as well as mortality [39, 40].\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u003cstrong\u003eParticipant timeline {13}\u003c/strong\u003e\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003eTable 1: Participant timeline.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"654\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd height=\"23\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eEnrolment\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eAllocation\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"6\" height=\"23\" style=\"width: 382px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003ePost-allocation\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"23\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eTIMEPOINT\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e-t\u003csub\u003e1\u003c/sub\u003e\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003e0\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eAdmission\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e6 weeks\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e12 weeks\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e6 months\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e12 months\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"23\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eAt event\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eENROLMENT\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eEligibility screen\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eInformed consent\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eAllocation\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eINTERVENTIONS\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eSurgery\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eASSESSMENTS\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eX-ray\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eCT scan\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX (pre-op)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eRadiostereometric imaging\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX (post-op)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eNew mobility score\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eModified Harris Hip Score\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eEQ-5D-5L\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003ePain Verbal Rating Scale\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eReoperation\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eComplication\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"36\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eDeath\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"36\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eX\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003ePre-op, before operation; Post-op, after operation; EQ-5D-5L, EuroQol 5 domain\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003e[Figure 2]\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eSample size {14}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePrimary outcome is shortening of the femoral neck at 12 weeks. A clinical relevance can be expected at \u0026gt;5mm shortening of the femoral neck [41]. Femoral neck shortening in the group randomised to internal fixation with CCS is expected to be 5.3mm (SD 4.5mm) at 6 weeks according to Van Embden et. al. [23]\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;and we do not expect further shortening of the femoral neck between 6 and 12 weeks. \u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003eUsing power 0.9, significance level 0.05, and expecting femoral neck shortening of maximum 1 mm for the angle stable implant (Dynaloc) compared with 5.3mm (SD 4.5mm) [23]\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;using three CCS a total sample size of N=50 can be calculated, N=25/group in this equality study design.\u0026nbsp;\u003cbr\u003e\u0026nbsp;We expect approximately 10% loss to follow-up and will therefore include a total of 54 patients.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eRecruitment {15}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eThe study will include patients from two hospitals in Denmark.\u0026nbsp;\u003cbr\u003e\u003c/span\u003eThe physician on call is responsible for including patients. A\u003cspan lang=\"EN-GB\"\u003ell eligible patients will be screened at admission and asked to participate in the study.\u0026nbsp;\u003c/span\u003e\u003cspan lang=\"EN-GB\"\u003ePatients will be recruited in the emergency department or in the ward prior to surgery.\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eAssignment of interventions: allocation\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eSequence generation {16a}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eIf informed consent is provided, eligible patients can be enrolled in the study.\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003ePatients will be entered into an electronic database (REDCap [42, 43]) and randomised to either CCS or Dynaloc using blocks of n=4 and n=6 and will be stratified based on the Garden classification (Garden 1-2 or 3-4) [44] to account for fracture displacement and stratified based on hospital of admission. The patients will be stratified according to the Garden classification as studies show significantly higher failure rates in Garden type 3 and 4 [45, 46]\u003cspan lang=\"EN-GB\"\u003e.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eConcealment mechanism {16b}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe operating surgeon will contact a central coordinator, who performs the randomisation using REDCap [42, 43], prior to the surgery. Therefore, the surgeon knows which implant to use before entering the operating theatre.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eImplementation {16c}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eThe randomisation and allocation will be performed by a central coordinator using REDCap\u0026nbsp;\u003c/span\u003e\u003cspan lang=\"EN-GB\"\u003e[42, 43]\u003c/span\u003e\u003cspan lang=\"EN-GB\"\u003e\u003c!--[if gte mso 9]\u003e\u003cxml\u003e 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The admitting physician will enrol participants and the operating surgeon will implement the assigned intervention.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eAssignment of interventions: Blinding\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eWho will be blinded {17a}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe implant and outcome will be blinded to trial participants and care providers. A standard phrase for the surgery will be used.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eProcedure for unblinding if needed {17b}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAccording to standards of care and journal publication requirements, the project staff can reveal the true surgery in case of severe pain or complications; otherwise, patients will be blinded until the end of the trial.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eData collection and management\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003ePlans for assessment and collection of outcomes {18a}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eProject staff will collect data, perform CT and RSA examinations and RSA analysis. Screening will be performed by the admitting doctor. Baseline data will be collected during admission and will be entered directly into REDcap by project personnel. Questionnaires will be sent directly to the patients using REDcap, and the answers will be automatically uploaded into REDcap. At the scheduled follow-ups, project personnel will see the patients in the outpatient clinic and check that the electronic questionnaires have been completed. The project personnel will obtain any missing information during the scheduled follow-ups and data will be entered directly into REDCap.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eRadiostereometric analysis\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRSA is a precise radiological method using two simultaneously obtained x-rays to measure migration of bone and implant models over time. It has classically been used to measure fixation of hip and knee arthroplasty but has also been used to measure fracture healing and displacement of intertrochanteric hip fractures [24]\u003cspan lang=\"EN-GB\"\u003e.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eAll patients will be subjected to a pre-operative CT scan of the hip/pelvis region for generating bone models (hip, pelvis and femur) to be used in the analyses of fracture migration over time (static RSA, non-weight-bearing recordings) and in the analyses of exploratory outcomes: Implant (screw) migration in the femoral head (static RSA, non-WB recordings) and inducible fracture migration (non-weight-bearing RSA recordings vs. weight-bearing RSA recordings at 6 weeks, 12 weeks and 12 months).\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eThe patients will be mobilised prior to baseline RSA. A check-off form has been designed for evaluating the degree of mobilisation (loading) during hospitalisation, to make sure the degree of mobilisation (loading) prior to baseline RSA is known. The check-off form includes different degrees of mobilisation from mobilisation to chair, standing with 50% load, \u0026gt;5m walking, \u0026gt;10m walking to free mobilisation. The need for walking aids and which type of walking aid used during mobilisation will also be registered.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003eTo ensure a load of 50% \u0026plusmn; 10% bodyweight during weight-bearing RSA recordings at follow-up a scale will be used, and the load will be registered on the X-ray. All bone models will be standardised with reference coordinate systems in order to estimate model migrations/movement and determine fracture healing and implant fixation. At 6 week follow-up double examination RSA recordings will be performed in order to validate the precision of the fracture migration measurements [28]\u003cspan lang=\"EN-GB\"\u003e.\u003cbr\u003e\u0026nbsp;AutoRSA software (in-house) will be used by project personnel for analyses of RSA recordings utilising CT bone models and surface models of the implant.\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003ePlans to promote participant retention and complete follow-up {18b}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eParticipants will be given extra follow-up appointments compared to the standard treatment plan for patients with internally fixated FNF. If the patients do not attend follow-up appointments, they will be contacted directly and invited to a new follow-up appointment promoting retention.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eData management {19}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStudy data will be collected and managed using REDCap electronic data capture tools hosted at OPEN, Region of Southern Denmark [42, 43]. REDCap (Research Electronic Data Capture) is a secure, web-based software platform designed to support data capture for research studies, providing 1) an intuitive interface for validated data capture; 2) audit trails for tracking data manipulation and export procedures; 3) automated export procedures for seamless data downloads to common statistical packages; and 4) procedures for data integration and interoperability with external sources. Data will be entered directly into REDCap and range checks will be applied where possible to ensure data quality.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eConfidentiality {27}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eProject data are securely stored in the project\u0026rsquo;s SharePoint and REDCap database during the active research period. Data will be entered via an encrypted connection which meets current requirements for data security. Data will be marked with identifiers, making it possible to deidentify data for the required storage.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003ePlans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eN/A, no biological specimens will be collected.\u0026nbsp;\u003c/span\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eStatistical methods\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eStatistical methods for primary and secondary outcomes {20a}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRandomisation groups will be kept blinded during statical analyses. The data distribution will be assessed and data presented accordingly. Continuous data will be analysed using Linear Mixed Model statistics and categorical data will be compared using the \u0026chi;2 test or the Fisher exact test.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eA p-value of \u0026lt;0.05 will be considered statistically significant. The postoperative complication rates will be defined as the sum of the individual rates of complications and reoperations. Mortality will be analysed using Cox-regression. Computerised statistical software packages (STATA 18, StataCorp) will be used for analyses and graphical presentation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eInterim analyses {21b}\u003c/span\u003e\u003c/strong\u003e\u003cspan lang=\"EN-GB\"\u003e\u003cbr\u003e\u003c/span\u003e\u003cspan lang=\"EN-GB\"\u003eDue to the relatively small sample size of the study, interim analysis is not planned. The coordinating investigator will monitor data closely during the study period. In the event of unforeseen complications in one or both study groups, the entire author group will be consulted, and the need for terminating the study will be discussed and decided in the author group (expert panel).\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eMethods for additional analyses (e.g. subgroup analyses) {20b}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eN/A\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e: N\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eo additional/subgroup analyses\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e are planned.\u003c/span\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eMethods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eIf a participant\u0026rsquo;s follow-up is discontinued, the participant\u003c/span\u003e will be omitted from a per-protocol analysis, but will be included in the intention-to-treat analysis. \u003cspan lang=\"EN-GB\"\u003eThe reason for discontinuation will be recorded in REDCap. \u0026nbsp;\u003cbr\u003e\u0026nbsp;If patients\u0026rsquo; baseline data and follow-up at 12 weeks have been recorded, the patient will be included in the statistical analysis through multiple imputation. The patient will otherwise be replaced to meet the calculated sample size.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003ePlans to give access to the full protocol, participant level-data and statistical code {31c}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eThe full protocol is registered in ClinicalTrials.gov and will be updated if the protocol is amended. Participant level data will not be made public, as data such as scans and radiostereometric imaging cannot be fully anonymised.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eOversight and monitoring\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eComposition of the coordinating centre and trial steering committee {5d}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eThe author group functions as the trial steering committee and the data monitoring committee due to a relatively small sample size in this RCT and consists of the coordinating/principal investigator at Odense\u0026nbsp;\u003c/span\u003eUniversity Hospital\u003cspan lang=\"EN-GB\"\u003e, the principal investigator at Aarhus\u0026nbsp;\u003c/span\u003eUniversity Hospital\u003cspan lang=\"EN-GB\"\u003e, the sponsor, two experts in RSA from Aarhus\u0026nbsp;\u003c/span\u003eUniversity Hospital\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;and an expert in RSA from Odense\u0026nbsp;\u003c/span\u003eUniversity Hospital\u003cspan lang=\"EN-GB\"\u003e.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eThe coordinating investigator will monitor the trial, recruitment, and data on an ongoing basis and be responsible for the day-to-day running of the trial in collaboration with the principal investigator at Aarhus\u0026nbsp;\u003c/span\u003eUniversity Hospital\u003cspan lang=\"EN-GB\"\u003e\u0026nbsp;and the sponsor. The entire group will meet biannually or as needed, depending on the trials phase. The principal investigators and the sponsor will meet weekly during the first months of inclusion, and thereafter monthly. Additional meetings will be held as necessary.\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eComposition of the data monitoring committee, its role and reporting structure {21a}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eN/A\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e:\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003e \u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003eP\u003c/span\u003e\u003c/em\u003e\u003cem\u003e\u003cspan lang=\"EN-GB\"\u003elease see above (5d)\u003c/span\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eAdverse event reporting and harms {22}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAny unforeseen complications that occur during the trial will be registered in the project\u0026rsquo;s REDCap database. All Adverse Events, Adverse Device Effects and Near-incidents will be registered. Serious Adverse Events, Serious Adverse Device Effects and Unanticipated Serious Adverse Device Effects will be registered and reported to sponsor immediately. The sponsor will report to the Danish Medicines Agency according to MDCG 2020-10/2 \u0026rdquo;Safety reporting in clinical investigations of medical devices under the Regulation (EU) 2017/745\u0026rdquo; [47]. All Serious Adverse Device Effects will be reported immediately and no later than 7 calendar days from the date the sponsor is made aware. All Serious Adverse Device Effects which indicate an immediate risk of death, serious injury, or serious illness will be reported immediately and no later than 2 calendar days from the date the sponsor is made aware.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eFrequency and plans for auditing trial conduct {23}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eX-ray images will be audited the day after admission by an orthopaedic surgeon and a radiologist independent from the primary investigators and sponsor. The primary investigators at each site will monitor the study. The electronic Case Report Forms in REDCap will weekly be monitored centrally by the coordinating investigator and will have an audit-trail. The coordinating investigator will continuously have an overview of the incoming data in REDCap and can thus discover trends, deviations in the study or differences between data.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003ePlans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees) {25}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan lang=\"EN-GB\"\u003eAny modifications or protocol amendments will be registered on ClinicalTrials.gov and the primary investigators of each site will be notified.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan lang=\"EN-GB\"\u003eDissemination plans {31a}\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe results will be published in an internationally peer-reviewed journal. Positive, negative and inconclusive results will be published. The protocol is registered in Clinical Trials in accordance with CONSORT guidelines [48]. Trial participants will be informed of the trial results in a layman\u0026rsquo;s summary.\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis is the first clinical RCT investigating the Dynaloc implant using RSA to evaluate fracture migration. The findings from this RCT can help evidence-based decision-making in a clinical setting when choosing surgical treatment for a FNF in young adults.\u003c/p\u003e\u003cp\u003eUsing RSA to evaluate the primary outcome, only a relatively small sample size is needed due to the high precision of the method [27]. An 8% dropout rate has been accounted for in the sample size calculation.\u003c/p\u003e\u003cp\u003eAnother strength of the study is the combined evaluation of measures of body structures and function, limitations to activities, and limitations to participation as well as mortality as recommended by the core outcome set for hip fracture trials [39, 40]. Defining the young adults as under 65 years of age is commonly used in research, and a cut-off point of 65 years of age was therefore chosen by the authors [49, 50]. Since this is just below the retirement age in Denmark, the cut-off point of 65 years can provide a homogenous group of participants, still employed at the time of inclusion, with a higher demand for postoperative function, compared to the elderly. A clinical frailty scale of up to and including 4 was chosen to ensure that the study participants are independent and, therefore, likely to have a higher demand for postoperative clinical and functional outcomes [2, 29].\u003c/p\u003e\u003cp\u003eRecruitment of 54 young adults with FNF that are eligible for inclusion may take time, as the incidence of FNF in young adults is low, which is why inclusion will take place at two hospitals. To prevent bias, the randomisation will be using blocks of 4 and 6 and will be stratified by study site.\u003c/p\u003e\u003cp\u003eIn conclusion, this study is expected to provide results from a clinical trial on the angle stable implant Dynaloc, evaluating both fracture migration and functional outcomes in young adults with FNF.\u003c/p\u003e\u003cp\u003e\u003cb\u003eTrial status\u003c/b\u003e\u003c/p\u003e\u003cp\u003eProtocol version 1.5\u003c/p\u003e\u003cp\u003eAuthor: MMH\u003c/p\u003e\u003cp\u003eThe trial was registered on 22/07/2024 in ClinicalTrials.gov (NCT06521671).\u003c/p\u003e\u003cp\u003eStatus: Recruitment is anticipated to start 01/04/2025 and is expected to conclude in 2027\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCCS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eCannulated cancellous screws\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eEQ-5D-5L\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eEuroQol 5 domain\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eFNF\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eFemoral neck fracture\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eRCT\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eRandomised controlled trial\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eRSA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eRadiostereometric analysis\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003eAcknowledgements\u003c/p\u003e\n\u003cp\u003eThe study has generously received financial support from the fund to support clinical doctoral candidates in the Region of Southern Denmark (Region Syddanmarks Ph.d.-pulje) and Swemac Innovation AB.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAuthors\u0026rsquo; contributions {31b}\u003c/p\u003e\n\u003cp\u003eMMH is the principal Investigator at Odense University Hospital and the coordinating Investigator; she led the protocol development in close collaboration with the last author, BV.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePHG is the principal investigator at Aarhus University Hospital and contributed to the development of the study protocol.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eETP and MS both contributed to the study design and the protocol development. They are the lead methodologists regarding RSA research.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMD contributed to the study design and the protocol development.\u003c/p\u003e\n\u003cp\u003eBV is the Sponsor and initiator of the study. Contributed to all phases of the study protocol development.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003eFunding {4}\u003c/p\u003e\n\u003cp\u003eThis study is part of a PhD project supported by the fund to support clinical doctoral candidates in the Region of Southern Denmark and Swemac Innovation AB. The funding is administered by the Orthopaedic Research Department at Odense University Hospital.\u003c/p\u003e\n\u003cp\u003eThe Region of Southern Denmark and Swemac Innovation AB do not intend to claim any raw data or influence over results from the study. Current and future funders have no role in design, execution, results or publication of the study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSwemac Innovation AB will receive written annual status updates from the project in terms of recruitment status as well as aggregated data for use in the company\u0026rsquo;s regulatory purposes.\u003c/p\u003e\n\u003cp\u003eAvailability of data and materials {29}\u003c/p\u003e\n\u003cp\u003ePatient information will be secured in a REDCap database [42, 43]. Access will be limited to the current trial workers, and will be limited to data entry only. The primary investigator will keep a list of trial worker with access to the database.\u003c/p\u003e\n\u003cp\u003eThe principal investigators and the sponsor will have access to the full final dataset. Swemac Innovation AB will receive aggregated anonymised data for use in the company\u0026rsquo;s regulatory purposes.\u003c/p\u003e\n\u003cp\u003eEthics approval and consent to participate {24}\u003c/p\u003e\n\u003cp\u003eThe trial will conform to the Declaration of Helsinki\u0026rsquo;s ethical principles [51]. Permission to conduct the study has been granted from The Danish National Medical Research Ethics Committee (ref. no. 2401073) and the participating Departments of Orthopaedic Surgery at Odense University Hospital and Aarhus University Hospital. The data protection regulation and the data protection act are complied with. By participating in the study, the patients will be subjected to a maximum of 10 mSv with the additional x-ray images and CT scan for AutoRSA, increasing the risk of inducing an incurable cancer due to radiation by 0.05% [52].\u003c/p\u003e\n\u003cp\u003eWritten, informed consent to participate will be obtained from all participants. Participants are covered by the insurance policies of ordinary treatment.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConsent for publication {32}\u003c/p\u003e\n\u003cp\u003eThe informed consent form and the written patient information sheet has been approved by The Danish National Medical Research Ethics Committee and is available upon request.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCompeting interests {28}\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003ePasoto, S.G., et al., Osteoporotic hip fractures in non-elderly patients: relevance of associated co-morbidities. Rheumatol Int, 2012. 32(10): p. 3149-53.\u003c/li\u003e\n\u003cli\u003eRogmark, C., et al., Hip fractures in the non-elderly-Who, why and whither? Injury, 2018. 49(8): p. 1445-1450.\u003c/li\u003e\n\u003cli\u003eWang, M.T., et al., Hip fractures in young adults: a retrospective cross-sectional study of characteristics, injury mechanism, risk factors, complications and follow-up. Arch Osteoporos, 2017. 12(1): p. 46.\u003c/li\u003e\n\u003cli\u003eZuckerman, J.D., Hip fracture. N Engl J Med, 1996. 334(23): p. 1519-25.\u003c/li\u003e\n\u003cli\u003eBartels, S., et al., High failure rate after internal fixation and beneficial outcome after arthroplasty in treatment of displaced femoral neck fractures in patients between 55 and 70 years. Acta Orthop, 2018. 89(1): p. 53-58.\u003c/li\u003e\n\u003cli\u003eBhandari, M. and M. Swiontkowski, Management of Acute Hip Fracture. N Engl J Med, 2017. 377(21): p. 2053-2062.\u003c/li\u003e\n\u003cli\u003eLy, T.V. and M.F. Swiontkowski, Management of femoral neck fractures in young adults. Indian J Orthop, 2008. 42(1): p. 3-12.\u003c/li\u003e\n\u003cli\u003eBhandari, M., et al., Operative management of displaced femoral neck fractures in elderly patients. An international survey. J Bone Joint Surg Am, 2005. 87(9): p. 2122-30.\u003c/li\u003e\n\u003cli\u003eDansk-Ortop\u0026aelig;disk-Selskab, Referenceprogram for patienter med hoftebrud. 2008. p. p. 128\u003c/li\u003e\n\u003cli\u003eSlobogean, G.P., et al., Complications following young femoral neck fractures. Injury, 2015. 46(3): p. 484-91.\u003c/li\u003e\n\u003cli\u003eZielinski, S.M., et al., Femoral neck shortening after internal fixation of a femoral neck fracture. Orthopedics, 2013. 36(7): p. e849-58.\u003c/li\u003e\n\u003cli\u003eStockton, D.J., et al., Incidence, Magnitude, and Predictors of Shortening in Young Femoral Neck Fractures. J Orthop Trauma, 2015. 29(9): p. e293-8.\u003c/li\u003e\n\u003cli\u003eSlobogean, G.P., et al., Femoral neck shortening in adult patients under the age of 55 years is associated with worse functional outcomes: Analysis of the prospective multi-center study of hip fracture outcomes in China (SHOC). Injury, 2017. 48(8): p. 1837-1842.\u003c/li\u003e\n\u003cli\u003eZlowodzki, M., et al., The effect of shortening and varus collapse of the femoral neck on function after fixation of intracapsular fracture of the hip: a multi-centre cohort study. J Bone Joint Surg Br, 2008. 90(11): p. 1487-94.\u003c/li\u003e\n\u003cli\u003eHamburger, E., et al., Femoral neck shortening as a sequela of internal fixation for femoral neck fractures and its effect on the coronal alignment of the limb: a pilot study. Arch Orthop Trauma Surg, 2024. 144(2): p. 723-729.\u003c/li\u003e\n\u003cli\u003eStockton, D.J., et al., High rate of reoperation and conversion to total hip arthroplasty after internal fixation of young femoral neck fractures: a population-based study of 796 patients. Acta Orthop, 2019. 90(1): p. 21-25.\u003c/li\u003e\n\u003cli\u003eWang, Z., et al., Comparison of early complications between the use of a cannulated screw locking plate and multiple cancellous screws in the treatment of displaced intracapsular hip fractures in young adults: a randomized controlled clinical trial. J Orthop Surg Res, 2018. 13(1): p. 201.\u003c/li\u003e\n\u003cli\u003eWu, Z.F., et al., Efficacy of the femoral neck system in femoral neck fracture treatment in adults: A systematic review and meta-analysis. World J Clin Cases, 2022. 10(31): p. 11454-11465.\u003c/li\u003e\n\u003cli\u003eYin, H., Z. Pan, and H. Jiang, Is dynamic locking plate(Targon FN) a better choice for treating of intracapsular hip fracture? A meta-analysis. Int J Surg, 2018. 52: p. 30-34.\u003c/li\u003e\n\u003cli\u003eBrattgjerd, J.E., et al., Increased torsional stability by a novel femoral neck locking plate. The role of plate design and pin configuration in a synthetic bone block model. Clin Biomech (Bristol, Avon), 2018. 55: p. 28-35.\u003c/li\u003e\n\u003cli\u003eBrattgjerd, J.E., et al., Interlocked Pins Increase Strength by a Lateral Spread of Load in Femoral Neck Fixation: a Cadaver Study. Acta Chir Orthop Traumatol Cech, 2021. 88(2): p. 144-152.\u003c/li\u003e\n\u003cli\u003eBrattgjerd, J.E., H. Steen, and K. Str\u0026oslash;ms\u0026oslash;e, Increased stability by a novel femoral neck interlocking plate compared to conventional fixation methods. A biomechanical study in synthetic bone. Clin Biomech (Bristol, Avon), 2020. 76: p. 104995.\u003c/li\u003e\n\u003cli\u003evan Embden, D., et al., The stability of fixation of proximal femoral fractures: a radiostereometric analysis. Bone Joint J, 2015. 97-b(3): p. 391-7.\u003c/li\u003e\n\u003cli\u003eKrogh, A.C., et al., No effect of hydroxyapatite-coated sliding hip screw threads on screw migration in the femoral head/neck of pertrochanteric fractures: a randomized controlled trial using radiostereometric analysis. J Orthop Surg Res, 2023. 18(1): p. 686.\u003c/li\u003e\n\u003cli\u003eFinnil\u0026auml;, S., et al., Radiostereometric analysis of the initial stability of internally fixed femoral neck fractures under differential loading. J Orthop Res, 2019. 37(1): p. 239-247.\u003c/li\u003e\n\u003cli\u003eAlm, C.E., et al., No benefit of the trochanteric stabilizing plate on loss of fracture reduction in AO/OTA 31-A2 trochanteric fractures. Bone Jt Open, 2024. 5(1): p. 37-45.\u003c/li\u003e\n\u003cli\u003eDerbyshire, B., R.J. Prescott, and M.L. Porter, Notes on the use and interpretation of radiostereometric analysis. Acta Orthop, 2009. 80(1): p. 124-30.\u003c/li\u003e\n\u003cli\u003eKaptein, B.L., et al., Guideline for RSA and CT-RSA implant migration measurements: an update of standardizations and recommendations. Acta Orthop, 2024. 95: p. 256-267.\u003c/li\u003e\n\u003cli\u003eRockwood, K., et al., A global clinical measure of fitness and frailty in elderly people. Cmaj, 2005. 173(5): p. 489-95.\u003c/li\u003e\n\u003cli\u003eParker, M.J. and K. Gurusamy, Modern methods of treating hip fractures. Disabil Rehabil, 2005. 27(18-19): p. 1045-51.\u003c/li\u003e\n\u003cli\u003eBorris, L., R. Thorninger, and O. Brinkmann, Premature discontinuation of a randomized comparison between a new implant Dynaloc\u0026reg; and cancellous screws for femoral neck fractures: An ethical dilemma. Journal of Traumatology and Clinical Orthopaedics, 2020.\u003c/li\u003e\n\u003cli\u003eKalland, K., et al., Similar outcome of femoral neck fractures treated with Pinloc or Hansson Pins: 1-year data from a multicenter randomized clinical study on 439 patients. Acta Orthop, 2019. 90(6): p. 542-546.\u003c/li\u003e\n\u003cli\u003eDolatowski, F.C., et al., Screw Fixation Versus Hemiarthroplasty for Nondisplaced Femoral Neck Fractures in Elderly Patients: A Multicenter Randomized Controlled Trial. JBJS, 2019. 101(2): p. 136-144.\u003c/li\u003e\n\u003cli\u003eLu, Q., et al., Hemiarthroplasty versus internal fixation in super-aged patients with undisplaced femoral neck fractures: a 5-year follow-up of randomized controlled trial. Archives of Orthopaedic and Trauma Surgery, 2017. 137(1): p. 27-35.\u003c/li\u003e\n\u003cli\u003eParker, M.J. and C.R. Palmer, A new mobility score for predicting mortality after hip fracture. J Bone Joint Surg Br, 1993. 75(5): p. 797-8.\u003c/li\u003e\n\u003cli\u003eByrd, J.W. and K.S. Jones, Prospective analysis of hip arthroscopy with 2-year follow-up. Arthroscopy, 2000. 16(6): p. 578-87.\u003c/li\u003e\n\u003cli\u003eHerdman, M., et al., Development and preliminary testing of the new five-level version of EQ-5D (EQ-5D-5L). Qual Life Res, 2011. 20(10): p. 1727-36.\u003c/li\u003e\n\u003cli\u003eBech, R.D., et al., The Verbal Rating Scale Is Reliable for Assessment of Postoperative Pain in Hip Fracture Patients. Pain Res Treat, 2015. 2015: p. 676212.\u003c/li\u003e\n\u003cli\u003eBryant, D.M., et al., Selection of outcome measures for patients with hip fracture. J Orthop Trauma, 2009. 23(6): p. 434-41.\u003c/li\u003e\n\u003cli\u003eHaywood, K.L., et al., Developing a core outcome set for hip fracture trials. Bone Joint J, 2014. 96-b(8): p. 1016-23.\u003c/li\u003e\n\u003cli\u003eFelton, J., et al., Femoral Neck Shortening After Hip Fracture Fixation Is Associated With Inferior Hip Function: Results From the FAITH Trial. J Orthop Trauma, 2019. 33(10): p. 487-496.\u003c/li\u003e\n\u003cli\u003eHarris, P.A., et al., The REDCap consortium: Building an international community of software platform partners. J Biomed Inform, 2019. 95: p. 103208.\u003c/li\u003e\n\u003cli\u003eHarris, P.A., et al., Research electronic data capture (REDCap)--a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform, 2009. 42(2): p. 377-81.\u003c/li\u003e\n\u003cli\u003eGarden, R.S., LOW-ANGLE FIXATION IN FRACTURES OF THE FEMORAL NECK. The Journal of Bone \u0026amp; Joint Surgery British Volume, 1961. 43-B(4): p. 647-663.\u003c/li\u003e\n\u003cli\u003eErivan, R., et al., Results of femoral neck screw fixation in 112 under 65-years-old at a minimum 2 years\u0026apos; follow-up. Orthop Traumatol Surg Res, 2020. 106(7): p. 1425-1431.\u003c/li\u003e\n\u003cli\u003eSprague, S., et al., Factors Associated With Revision Surgery After Internal Fixation of Hip Fractures. J Orthop Trauma, 2018. 32(5): p. 223-230.\u003c/li\u003e\n\u003cli\u003eMedical-Device-Coordination-Group, MDCG 2020-10/1 Safety reporting in clinical investigations of medical devices under the Regulation (EU) 2017/745. 2020.\u003c/li\u003e\n\u003cli\u003eCuschieri, S., The CONSORT statement. Saudi J Anaesth, 2019. 13(Suppl 1): p. S27-s30.\u003c/li\u003e\n\u003cli\u003eLee, A., et al., Predicting life expectancy after geriatric hip fracture: A systematic review. PLoS One, 2021. 16(12): p. e0261279.\u003c/li\u003e\n\u003cli\u003eLee, S.B., et al., Differences in youngest-old, middle-old, and oldest-old patients who visit the emergency department. Clin Exp Emerg Med, 2018. 5(4): p. 249-255.\u003c/li\u003e\n\u003cli\u003eWorld Medical Association Declaration of Helsinki. Ethical principles for medical research involving human subjects. Bull World Health Organ, 2001. 79(4): p. 373-4.\u003c/li\u003e\n\u003cli\u003eNational-Videnskabsetisk-Komit\u0026eacute;, Appendiks 2 Retningslinjer om anvendelse af ioniserende stråling i sundhedsvidenskabelige fors\u0026oslash;g. 2011.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"trials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"trls","sideBox":"Learn more about [Trials](http://trialsjournal.biomedcentral.com/)","snPcode":"13063","submissionUrl":"https://www.editorialmanager.com/trls","title":"Trials","twitterHandle":"MedicalEvidence","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Clinical outcome, randomised controlled trial, femoral neck fracture, internal fixation, fracture migration, radiostereometric analysis","lastPublishedDoi":"10.21203/rs.3.rs-5433232/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5433232/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHip fractures are most commonly suffered by elderly patients, but 2–11% of hip fractures affect younger patients. In young adults with femoral neck fractures, internal fixation is the recommended treatment for both displaced and non-displaced fractures. However, treatment with internal fixation carries a high complication rate. A known complication of internal fixation after gold standard cannulated cancellous screws is fracture compression resulting in shortening of the femoral neck, which is associated with clinically important decreases in functional outcome. New osteosynthesis implants have been developed to prevent fracture compression and improve the outcomes of internal fixation of femoral neck fractures. Recent preliminary clinical and biomechanical studies show that implants with interlocking screws and/or angle stability have promising results compared to standard internal fixation with cannulated cancellous screws. Measurement and comparison of three-dimensional fracture displacement requires precise method, which may be accommodated with CT bone models and weight-bearing radiostereometric imaging in the months after surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 54 young adults under 65 years of age with femoral neck fractures will be electronically randomised to treatment with either internal fixation with cannulated cancellous screws (gold standard) or an angle stable implant (Dynaloc, Swemac). Patients will be excluded if they are unable to understand the study information, have a transcervical, basicervical or pathological fracture, or present clinically as frail. Primary outcome measure is fracture migration at 12 weeks measured in radiostereometric imaging using CT bone models and AutoRSA software. Secondary outcomes will be fracture migration in terms of femoral neck shortening at 6 weeks, function scores and pain Verbal Rating Scale at 6 and 12 weeks, surgical complications, reoperation, and mortality at event.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDiscussion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis clinical trial will examine fracture migration and the functional outcomes of internally fixated femoral neck fractures in young adults by comparing the results of an angle stable implant (Dynaloc, Swemac) compared with cannulated cancellous screws. The study has perspective to provide scientific evidence for empirical decision-making when choosing implants for femoral neck fractures in young adults.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClinicalTrials.gov ID: NCT06521671. 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