Reverse shoulder arthroplasty versus locking plate fixation for proximal humeral fracture dislocations in elderly patients: study protocol for a randomized controlled trial

Reverse shoulder arthroplasty versus locking plate fixation for proximal humeral fracture dislocations in elderly patients: study protocol for a randomized controlled trial | 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 Study protocol Reverse shoulder arthroplasty versus locking plate fixation for proximal humeral fracture dislocations in elderly patients: study protocol for a randomized controlled trial Yijie Chai, Haochen Jiang, Haoning He, Longxiang Shen, Yunfeng Chen, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6080611/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 04 Jun, 2025 Read the published version in Journal of Orthopaedic Surgery and Research → Version 1 posted 6 You are reading this latest preprint version Abstract Background : Proximal humeral fractures are common injuries in the elderly population, with their incidence expected to rise due to increased life expectancy. A small subset of these fractures may be associated with dislocating forces that can result in shoulder dislocation concurrent with the fracture. For the elderly patients, proximal humeral fracture dislocation can be treated by open reduction and internal locking plate (LP) fixation or reverse shoulder arthroplasty (RSA). By now, no high-quality trials have compared the two. Methods : This study is a prospective, single-center, superiority randomized controlled trial (RCT) comparing RSA and LP fixation in elderly patients (aged 65 to 85 years) with a proximal humeral fracture dislocation. Eligible participants will be randomly assigned to either the RSA or LP group (1:1 ratio). Postoperative follow-up will be conducted at 1 day (in the ward), 1 month, 3 months, 6 months, 12 months, and 24 months after surgery. Primary outcome is the Constant-Murley Score at 1-year postoperatively. Secondary outcomes include short version of Disabilities of the Arm Shoulder and Hand questionnaire score, American Shoulder and Elbow Surgeons score, Visual Analog Scale score, EuroQol-5 Dimension score, range of motion, strength and postoperative complications. Discussion : This trial is the first RCT comparing RSA with LP fixation for proximal humeral fracture dislocations in elderly patients. The results of this study will provide high-quality evidence to guide clinical practice. Trial Registration : China Clinical Trials Registry No. ChiCTR2400088249. Proximal humeral fracture Dislocation Reverse shoulder arthroplasty Locking plate fixation Randomized controlled trial Figures Figure 1 Figure 2 Figure 3 Background Proximal humeral fractures are common fractures in the elderly population, and their incidence is anticipated to increase significantly due to the rising life expectancy [1-3]. A small subset of these fractures can be concurrent with a shoulder dislocation, which often results in more severe pain and functional impairment than isolated fractures. Moreover, those dislocations (except those combined with isolated greater/lesser tuberosity fractures) always cannot be reduced manually, as a result, necessitate a surgical intervention [4]. Open reduction and internal fixation with a locking plate (LP), which involves plates and screws designed to conform to the anatomy of the proximal humerus to facilitate fracture healing and restore joint function, is a common surgical technique for treating proximal humeral fracture dislocations. A systematic review study indicated that LP treatment for patients with proximal humeral fracture dislocations although achieve reasonable functional outcomes in general, the rates of humeral head necrosis and reoperation are relatively high [5]. From another perspective, proximal humeral fracture dislocations in the elderly can also be treated with shoulder replacement, and in most cases, reverse shoulder replacement (RSA) is applied. Several studies reported RSA could yield satisfactory results in these patients [6-8]. The rationale for RSA includes: 1) significant vascular disruption to the proximal humerus increases the incidence of humeral head necrosis after LP fixation (approximately 20%), necessitating subsequent arthroplasty [9-11]; 2) the rotator cuff, which is essential for shoulder movement, is frequently compromised in association with dislocation trauma or in elderly patients, resulting in poor shoulder function despite fracture healing after locking plate fixation [12-13] ;3) the technical demands of LP fixation for such injuries are high, making anatomical reduction challenging. Currently, there is evidence supporting that both RSA and LP can achieve favorable outcomes in the treatment of elderly patients with proximal humeral fracture dislocations [5-8]. Although some studies, such as Joseph et al., suggest that RSA may be superior to LP—citing a successful clinical outcome in an 80-year-old patient with a four-part proximal humeral fracture and subsequent dislocation, and recommending RSA over traditional LP fixation—this conclusion is not strongly supported by high-level evidence [14]. Therefore, conducting a high-quality clinical trial comparing the effectiveness of LP fixation with RSA in the treatment of elderly proximal humeral fracture dislocations would be meaningful. Here we present a protocol of a prospective, single-center, superiority randomized clinical trial to compare RSA and LP fixation in elderly patients with a proximal humeral fracture dislocation. We hypothesize that RSA provides better shoulder outcomes compared to LP fixation. The successful execution of this trial will provide clinical data to support the assessment of the effectiveness of both procedures in treating proximal humeral fracture dislocations, offering high-quality medical evidence to guide future clinical decision-making. Methods Study setting and trial design This study is a prospective, single-center, superiority randomized controlled trial. Eligible participants will be randomly assigned to two groups: LP group and the RSA group. Assessments will be conducted at baseline, postoperative day 1, and at postoperative 1, 3, 6, 12, and 24 months for all participants. See participant flowchart in Figure 1. Any changes to the protocol that could impact the study's execution, patient outcomes, or safety—including modifications to study objectives, design, participant demographics, sample size, procedures, or critical administrative details—require a formal protocol amendment. Ethical approval for the study was obtained from the Ethics Committee of Shanghai Sixth People’s Hospital (2024-110). All participants will provide written informed consent before data collection begins. This trial is registered with the Chinese Clinical Trial Registry (registration number: ChiCTR 2400088249). Recruitment Patients with proximal humeral fractures presenting to the outpatient and emergency departments of our hospital will undergo screening. At this stage, frontline physicians will make the diagnosis of proximal humeral fracture dislocation by reviewing the patient’s medical history, performing a physical examination, and analyzing initial X-rays and Computed Tomography (CT) scans. The initial X-ray of the injured shoulder includes standard anteroposterior and lateral views. Once the diagnosis is confirmed, a member of the trial researchers will assess eligibility by reviewing the patient's medical history, physical examination, and imaging data within 24 hours. If the patient appears to meet the inclusion and exclusion criteria, he/she will be contacted in person or by phone for a further evaluation, during which the trial details will be explained. If the patient expresses interest in participating, the researcher will provide further explanation and written information about the study. Patients who consent to participate will be asked to sign a written informed consent form. With obtaining informed consent, the patient will be scheduled for an enhanced shoulder MRI (3.0 T, resolution 1.5, slice thickness 3 mm) examination. To be noted, if a large rotator cuff tear were found by MRI at this stage (defined as a tear with a diameter of 5 cm), the patient would be excluded according to the exclusion criteria. Eligibility criteria Patients who meet all the inclusion criteria, and none of the exclusion criteria will be eligible. Inclusion criteria: 1.Age 65 to 85 years (including 65 and 85 years); 2.Unilateral proximal humeral fractures combined with a shoulder dislocation, (Neer type VI) based on injury history, physical examination, X-rays, and CT scans; 3.Patients with a general condition that permits them to tolerate surgery; 4.Acute fracture (within 3 weeks of injury); 5.Patients who provide written consent to participate. Exclusion criteria: 1.Shoulder dislocations with isolated greater/lesser tuberosity fractures; 2.MRI-confirmed large rotator cuff tears(a tear with a diameter of 5 cm) [15]; 3.Patients with axillary nerve injury or deltoid muscle strength of grade 4(based on Medical Research Council scale) or lower on the affected side [16]; 4.Patients with contraindications to MRI (e.g., pacemakers, claustrophobia); 5.Gustilo-Anderson type III open fractures or open fractures with vascular or nerve injuries; 6.Patients with pathological fractures, such as those associated with tumors, osteomalacia, osteomyelitis, or simple bone cysts； 7.Patients with a history of previous trauma or surgery to the ipsilateral upper limb; 8.Patients with psychiatric disorders or who do not understand Chinese and are unable to comprehend and independently complete the questionnaire. Allocation An independent staff member, who is not involved in the trial's implementation, will generate the randomization index using an encrypted Electronic Data Capture (EDC) system. The randomization will use a 1:1 ratio (RSA group: LP group) with randomly sized blocks (block sizes of 4, 6, or 8) and will be stratified based on the Neer fracture classification (two-part, three-part, or four-part fractures). No one except this independent staff member will have access to the randomization results. Once the patients sign the written informed consent and complete the baseline assessment, they will be assigned a unique trial number. The researcher assisting with the baseline assessment will notify the staff member responsible for randomization to proceed with the enrollment. The staff member generating the randomization will then inform the surgical team and the patient of the randomization results at least 24 hours prior to surgery. Blinding Given the nature of the surgical intervention, blinding of participants or clinicians who perform the surgery is not possible. The researcher performing the imaging evaluations also will not be blinded. The trial statisticians analyzing the data and the clinicians conducting the functional follow-up assessments will be blinded. We will ensure that the clinicians conducting the functional follow-up assessments are blinded using the following procedure: researchers will take photographs of the patients to document shoulder function (as shown in Figure 2). All photos will be anonymized and collected for centralized evaluation after the completion of all follow-ups. The centralized evaluation will be conducted by two independent reviewers during a dedicated reading session. After the completion of the statistical analysis, the statistician and the clinicians conducting the functional follow-up assessments will be unblinded. Procedure prior surgery After enrollment, relevant baseline information of the included patients will be recorded: age(year), sex(male/female) height(cm), weight(kg), education level (no formal education/primary education/secondary education/vocational education/ higher education), marital status(unmarried/married), dominant hand(left/right), smoking and alcohol history, presence of comorbidities, cortical thickness of the proximal humerus(mm), Neer fracture classification and AO/OTA 2018 classification [17]. The cortical thickness of the proximal humerus will be measured using the Tingart index method to assess the patients’ osteoporosis status [18]. Additionally, an immediate pain assessment will be conducted using the Visual Analog Scale(VAS) score, and baseline shoulder X-ray, CT-scan and MRI examinations will be performed. Interventions RSA RSA modifies the conventional anatomy of the shoulder's ball-and-socket joint by positioning the humeral head (the 'ball') in the glenoid (the 'socket') and vice versa, effectively stabilizing the center of rotation of the glenohumeral joint, similar to the function of a healthy rotator cuff [19]. The surgeon and the patient in this group will jointly decide which type of reverse shoulder prosthesis to use prior to surgery, either the inlay (Trabecular Metal® Reverse Shoulder System, Zimmer Biomet, USA) or the onlay (Comprehensive® Reverse Shoulder System, Zimmer Biomet, USA). During the procedure, usually a biologic prosthesis will be used without bone cement, and bone cement will only be considered for reinforcement if instability or loosening of the prosthesis is observed. The long head of the biceps tendon will be cut and fixed during surgery, either with an anchor or sutured to the conjoint tendon. Both the greater and lesser tuberosities, as well as the rotator cuff, are reconstructed during the procedure. The implanted prosthesis and the location of the tuberosities will be confirmed and documented before the end of the operation by intraoperative fluoroscopic films, and then wound will be irrigated and closed in layers. LP fixation LP fixation is a commonly used surgical technique for the treatment of proximal humeral fractures. The primary goal of this operation is to achieve anatomic fracture reduction and fixation. Patient will be placed in a beach-chair position under general anesthesia. The deltopectoral approach will be used. Tuberosity fragments (if exist) will be re-connected to the rotator cuff using nonabsorbable sutures to promote reduction, and the sutures will be attached on the looking plate afterwards. Rotator cuff tears (if exist) will be sutured at the same time. After fracture reduction, K-wires are used for temporary fixation, and a C-arm X-ray machine will be used to ensure reduction. A locking plate (Philos, Synthes®, Switzerland) will be placed on the lateral to the bicipital groove once the reduction is satisfactory. The superior part of the locking plate will be placed no higher than 5 mm below the top of the greater tuberosity. Screws will be inserted afterwards. Next, final fracture fixations will be checked and documented by the intraoperative fluoroscopic films; the wound will then be irrigated and closed in layers. Rehabilitation Conduct rehabilitation interventions for patients following standardized guideline procedures [20-22]. Postoperative management requires patients to wear either an abduction-neutral brace or an abduction-external rotation brace for 4 to 6 weeks, contingent upon whether the fracture is associated with dislocation. Weight-bearing on the affected limb is strictly prohibited during the initial 6 weeks following surgery. In the first 0–3 days of hospitalization, patients are guided to perform active range-of-motion (AROM) exercises for the elbow and wrist, engage in pendulum exercises, and apply ice therapy for pain and inflammation control. Prior to the first postoperative follow-up, scheduled within 4 weeks, patients are expected to adhere to a home-based rehabilitation protocol provided by the Physiotherapist. This rehabilitation plan includes passive shoulder flexion and abduction exercises restricted to 90 degrees, passive external rotation limited to 20 degrees, isometric contractions targeting the forearm muscles, and scapular mobility exercises. Between the third- and fourth-weeks post-surgery, patients gradually transition from passive range-of-motion (PROM) exercises to active-assisted range-of-motion (AAROM) exercises, performed in a supine position. Following the first postoperative follow-up, the orthopedic surgeon and rehabilitation therapist collaboratively determine the next phase of rehabilitation. During the second- and third-months post-surgery, patients progress from AAROM to full AROM exercises for the shoulder. Isometric exercises for the shoulder muscles are incrementally advanced to isotonic resistance training. Depending on the patient’s clinical condition, physical modalities and manual therapy may be incorporated into the rehabilitation process. After the third postoperative month, therapeutic exercises and manual therapy specifically addressing shoulder stability and flexibility are conducted under the therapist’s guidance. The comprehensive rehabilitation plan is detailed in Figure 3. Follow-up measurements The surgical information of the patients will be recorded: time from injury to surgery (hours), surgery date, operating surgeon (name), duration of surgery (minutes), and intraoperative blood loss (ml). Postoperative follow-up will be conducted at 1 day (in the ward), 1 month, 3 months, 6 months, 12 months, and 24 months after surgery, in a designated follow-up room or outpatient orthopedic clinics. During each follow-up, the patient will meet with an orthopedic physician for disease-related consultation and to receive imaging examinations. Additionally, the patient will meet with a researcher in a designated follow-up room, where the researcher will deliver questionnaires and take photographs to assess shoulder functions. The data collection timetable is outlined in Table 1. Outcomes The primary outcome is the Constant-Murley Score (CMS) at 1 year postoperatively, which includes four subscales: pain (15 points), activities of daily living (20 points), strength (25 points), and range of motion (40 points) [23]. The total score ranges from 0 to 100, with higher scores indicating better functional outcomes. The range of motion section of the CMS will be independently assessed by two reviewers under blinded conditions. The final score will be obtained by averaging the scores assessed by the two reviewers. Secondary outcomes will include: 1.changes in VAS scores for pain (ranging from 0 to 100, with higher scores indicating greater pain severity) at postoperative days 1, 1 month, 3 months, 6 months, 12 months, and 24 months [24]; 2.changes in CMS at postoperative 1 month, 3 months, 6 months, and 24 months; 3.changes in Disabilities of the Arm Shoulder and Hand questionnaire(QuickDASH) scores (ranging from 0 to 100, with higher scores indicating worse shoulder function) at postoperative 1 month, 3 months, 6 months, 12 months, and 24 months [25]; 4.changes in American Shoulder and Elbow Surgeons (ASES) scores (ranging from 0 to 100, with higher scores indicating better shoulder function) at postoperative 1 month, 3 months, 6 months, 12 months, and 24 months [26]; 5.changes in EuroQol-5 Dimension (EQ-5D) quality of life scores at postoperative 1 month, 3 months, 6 months, 12 months, and 24 months; 6.changes in shoulder range of motion (ROM) testing scores (ranging from 0 to 40, with higher scores indicating better range of motion) at postoperative 1 month, months, 6 months, 12 months, and 24 months; 7.MRI evaluation of humeral head avascular necrosis (yes/no) in the locking plate group at 12 and 24 months postoperatively [27]; 8.incidence of complications on postoperative days 1, 1 month, 3 months, 6 months, 12 months, and 24 months; 9.use of co-medications or co-treatments at postoperative days 1, 1 month, 3 months, 6 months, 12 months, and 24 months; 10.adverse event (including serious adverse events) on postoperative days 1, 1 month, 3 months, 6 months, 12 months, and 24 months; 11.surgical quality: determined upon discussion within two senior orthopedic surgeons based on the intraoperative fluoroscopic films (3 levels: poor/acceptable/satisfactory). If the evaluation result is ‘poor’ or ‘acceptable’, the reasons for the assessment will be documented. Sample size We calculated the sample size based on the primary outcome (CMS). Since there have been no prior prospective clinical trials specifically targeting elderly patients with proximal humeral fracture dislocation, we used retrospective study evidence and data from similar populations in previous prospective studies [28-29]. The standard deviation of the CMS for both groups at 1 year postoperatively is assumed to be 16, and the minimum clinically important difference (MCID) between groups is set at 10 points. With a power of 80% and a significance level (α) of 0.05, the calculated required sample size is 42 patients per group. To account for an anticipated loss to follow-up rate of 20%, 53 patients will be enrolled in each group [28,29]. Statistical methods Baseline Demographic Data The baseline demographic data for both groups will be presented as means (standard deviations) or counts (percentages). Analysis will be done based on an intention-to-treat (ITT) principle. All the patients who have been randomized will be included in analysis and be grouped by the results of randomization. Significance level is set at 0.05. The data analyst will be blinded for treatment allocations. The CMS will be analyzed using a linear mixed model with repeated measures to calculate the inter-group differences over time. The model structure will be selected based on the lowest Akaike Information Criterion (AIC). Fixed effects will include time and the interaction between time and group, while baseline CMS and the random stratification variable (i.e., Neer fracture type) will be included as covariates. Inter-group mean differences and their 95% confidence intervals will be calculated at each time point, with the inter-group mean difference at the 1-year postoperative follow-up serving as the primary outcome. In the event of baseline demographic imbalances between the two treatment groups post-randomization, and if the researchers determine that these variables are significantly associated with the outcome measures (defined as differences exceeding 10%), sensitivity analyses will be performed to incorporate and adjust for these variables in the statistical analysis model. The same linear mixed model with repeated measures will be applied to analyze inter-group differences for continuous variables among the secondary outcomes at each follow-up time point. Postoperative complication rates will be described. If the complication rates exceed 10% in both groups at the 2-year follow-up, a generalized linear model will be used to compare overall complication rates between the two groups. Adverse events and co-treatments will be reported descriptively without statistical analysis. Missing values Missing values may arise from incomplete questionnaires or loss to follow-up. Although linear mixed models account for missing data, results may become invalid when a significant proportion of values are missing (>5%, rule of thumb) [30]. Additionally, the assumption of missing values completely at random may not hold [31]. To assess the robustness of our findings, a sensitivity analysis using multiple imputations will be conducted. Exploratory subgroup analysis Predefined exploratory subgroup analyses will be performed to assess the interaction between baseline Neer fracture classification (i.e., the random stratification factor: two-part, three-part, and four-part fractures) and the primary outcome measures between the two groups. Discussion Proximal humeral fractures are prevalent among the elderly and are anticipated to increase due to rising life expectancy. A subset of these fractures occurs concurrently with shoulder dislocations, leading to more severe pain and functional impairment. While current treatment options include internal locking plate fixation and reverse shoulder arthroplasty, there is a lack of high-quality trials directly comparing the effectiveness of these approaches in elderly patients with proximal humeral fracture dislocations. This trial is a prospective, single-center, superiority randomized controlled trial designed to compare the clinical effectiveness of reverse shoulder arthroplasty and locking plate fixation in elderly patients (aged 65 to 85 years) with proximal humeral fracture dislocations. This trial has several advantages. First, it is the first randomized controlled trial to compare RSA and LP fixation for the treatment of proximal humeral fracture dislocations in elderly patients. Second, we preemptively control for the confounding factor of fracture classification by using stratified block randomization. Third, our follow-up duration extends to 2 years, which not only allows for the assessment of patients' functional recovery at different postoperative time points, providing insight into the continuity and stability of recovery, but also helps in capturing potential long-term complications, such as humeral head avascular necrosis in the LP group. This study also has limitations. For example, this study is a single-center study, which may have limitations in sample representativeness compared to multi-center studies. However, our hospital, as the National Center for Orthopedics, receives patients from across the country. Given the low incidence and complexity of the injury under investigation, most hospitals refer such cases to our center. Therefore, the sample in this study is expected to be relatively representative. Furthermore, designing a multicenter study may be challenging, as other centers may struggle to recruit appropriate patients. Another disadvantage is the inevitable lack of blinding. Since the intervention involves surgical treatment, blinding of participants or clinicians performing the surgery is not possible. However, we have adhered to the principle of blinding as much as possible. For instance, the trial statisticians analyzing the data and the clinicians conducting the functional follow-up assessments will remain blinded. In conclusion, the results of this trial are expected to provide high-quality evidence to guide clinical practice in the use of LP fixation and RSA for elderly proximal humeral fracture dislocations. Trial status The first patient was enrolled on 19 Aug 2024; enrolment is anticipated to complete by 1st Aug 2028. Approximately 106 patients are expected to be enrolled. List of abbreviations LP Locking plate RSA Reverse shoulder arthroplasty RCT Randomized controlled trial CMS Constant-Murley score QuickDASH Quick version of Disabilities of the Arm Shoulder and Hand ASES American Shoulder and Elbow Surgeons VAS Visual Analog Scale EDC Electronic Data Capture ROM Shoulder range of motion MCID Minimum clinically important difference ITT Intention-to-treat Declarations Ethics approval and consent to participat e Ethical approval for the study was obtained from the Ethics Committee of Shanghai Sixth People’s Hospital (2024-110). All participants will provide written informed consent before data collection begins. This trial is registered with the Chinese Clinical Trial Registry (registration number: ChiCTR 2400088249). The patients enrolled provided written informed consent to participate in the study. Consent for publication The patients who were enrolled provided written informed consent for the publication of their data for scientific purposes. Availability of data and material The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request. Competing interests The authors declare no competing interests. Funding The institution of one or more of authors (YFC,QKW) has received, during the study period, funding from The Institutional Research Project of Shanghai Sixth People's Hospital (ynts202402) and the Municipal Hospital Newly‐developing Cutting‐edge Technologies Joint Research Program of Shanghai Shenkang Hospital Development Center(SHDC12021117). Authors' contributions The authors confirm that they made the following contributions to the paper. Study conception and design: first author; acquisition of data: all authors; analysis and interpretation of data: all authors; draft manuscript preparation and critically revisiting the manuscript for intellectual content: all authors. All authors reviewed the results and approved the final version of the manuscript. Acknowledgements Not applicable. Authors' information 1 Department of Orthopaedics, Shanghai Sixth People's Hospital, Shanghai, China. 2 National Center for Orthopaedics, Shanghai Sixth People's Hospital, Shanghai, China. 3 Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China. References Court-Brown CM, Duckworth AD, Clement ND, et al. Fractures in older adults. A view of the future? Injury. 2018 Dec;49(12):2161-2166. Dauwe J, Danker C, Herteleer M, et al. Proximal humeral fracture osteosynthesis in Belgium: a retrospective population-based epidemiologic study. Eur J Trauma Emerg Surg. 2022 Dec;48(6):4509-4514. Roux A, Decroocq L, El Batti S, et al. Epidemiology of proximal humerus fractures managed in a trauma center. Orthop Traumatol Surg Res. 2012 Oct;98(6):715-9. Kelly BJ, Myeroff CM. Reverse Shoulder Arthroplasty for Proximal Humerus Fracture. Curr Rev Musculoskelet Med. 2020 Apr;13(2):186-199. Miltenberg B, Masood R, Katsiaunis A, et al. 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When and how should multiple imputation be used for handling missing data in randomised clinical trials - a practical guide with flowcharts. BMC Med Res Methodol. 2017 Dec 6;17(1):162. Ibrahim JG, Molenberghs G. Missing data methods in longitudinal studies: a review. Test (Madr) 2009;18(1):1-43. doi: 10.1007/s11749-009-0138-x. Table 1 Table 1 . Follow-up measurements. Time point baseline 1 d ay 1 m onth 3 m onth 6 m onth 12 m onth 24 m onth General Information x Surgical Information x Constant-Murley Score x x x x x QuickDASH Score x x x x x ASES Score x x x x x EQ5D Score x x x x x Visual Analogy Score x x x x x x x Range of Motion x x x x x Shoulder trauma series X-rays x x x x x x x Shoulder MRI x x x Complications x x x x x x Patient Satisfaction x Concomitant treatments x x x x x x Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 04 Jun, 2025 Read the published version in Journal of Orthopaedic Surgery and Research → Version 1 posted Editorial decision: Revision requested 06 May, 2025 Reviews received at journal 01 May, 2025 Reviewers agreed at journal 01 May, 2025 Reviewers invited by journal 29 Apr, 2025 Submission checks completed at journal 29 Apr, 2025 First submitted to journal 28 Apr, 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-6080611","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Study protocol","associatedPublications":[],"authors":[{"id":449817627,"identity":"99457a8f-305b-4672-b7ec-bfeb3fb67706","order_by":0,"name":"Yijie Chai","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8UlEQVRIie3RMWrDMBTG8U8I5EWOV5kOuUK7ZGrTq0gYPJUuuYAhkCw9gLs0V0gXd5URdCr0AJ66eJaXkkAofc7WobbHQvVfBI/3AwkBodAf7NJBW2Cpwfmr6icimkYyIiJX0ET4CEmL81HTrlycCcZIEuHDetj7ZCs/VXeo5jMO5ru73wldQ9cl7Eq5+OVY6uZqw8HTx2qYOAlrChdXF1I3jIjg8Rg5Edk52fbkdhqh55u9k6InZhKpH5CZZycWaZk32Yaz9fBbkrfMH7A0T++uVf66udlt17XvBgh9hwb7+jFhxdA+FdmRhVAoFPr3fQOlMU6BBVN1bQAAAABJRU5ErkJggg==","orcid":"","institution":"Shanghai Sixth People's Hospital","correspondingAuthor":true,"prefix":"","firstName":"Yijie","middleName":"","lastName":"Chai","suffix":""},{"id":449817628,"identity":"c90da687-df44-43fc-9648-cf8c69c2fc30","order_by":1,"name":"Haochen Jiang","email":"","orcid":"","institution":"First Affiliated Hospital of Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Haochen","middleName":"","lastName":"Jiang","suffix":""},{"id":449817629,"identity":"58ebc138-0266-4eca-9a6f-e0e51ae94982","order_by":2,"name":"Haoning He","email":"","orcid":"","institution":"Shanghai Sixth People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Haoning","middleName":"","lastName":"He","suffix":""},{"id":449817630,"identity":"73d85e3f-882e-4a1b-8fde-3209dee7c92c","order_by":3,"name":"Longxiang Shen","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Longxiang","middleName":"","lastName":"Shen","suffix":""},{"id":449817631,"identity":"c23a28c6-2b7b-47a8-b93b-7764ebcd1f25","order_by":4,"name":"Yunfeng Chen","email":"","orcid":"","institution":"Shanghai Sixth People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yunfeng","middleName":"","lastName":"Chen","suffix":""},{"id":449817632,"identity":"58cdef04-f7b8-41d6-bdbb-e4ef75b3a3f8","order_by":5,"name":"Qiuke Wang","email":"","orcid":"","institution":"Shanghai Sixth People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Qiuke","middleName":"","lastName":"Wang","suffix":""}],"badges":[],"createdAt":"2025-02-21 15:08:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6080611/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6080611/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s13018-025-05982-y","type":"published","date":"2025-06-04T15:57:09+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":82074885,"identity":"81f9d339-38f6-4635-87dd-92d17a76af1a","added_by":"auto","created_at":"2025-05-06 13:40:00","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":53155,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFlowchart of the trial\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6080611/v1/db3be35d04904aef11fd4595.jpg"},{"id":82075720,"identity":"3b7f4ab0-e305-4518-bc3a-0659ca7af647","added_by":"auto","created_at":"2025-05-06 13:48:00","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":86158,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA-D An example of patient’ shoulder function photos\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFig.2-A Abduction function of shoulder；\u003c/p\u003e\n\u003cp\u003eFig.2-B Flexion function of shoulder；\u003c/p\u003e\n\u003cp\u003eFig.2-C External rotation function of shoulder；\u003c/p\u003e\n\u003cp\u003eFig.2-D Internal rotation function of shoulder.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6080611/v1/07e03f7915ecb7352f4b4f23.jpg"},{"id":82074887,"identity":"c881ab03-67ce-42e1-8ee0-8e08451bdad4","added_by":"auto","created_at":"2025-05-06 13:40:00","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":188765,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eRehabilitation Treatment Protocol for Proximal Humerus Fractures\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6080611/v1/2aeead41ea511e93f5731c39.jpg"},{"id":84242487,"identity":"689ed6d1-7732-4ff7-aeb1-78effcfd408b","added_by":"auto","created_at":"2025-06-09 16:08:25","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1041578,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6080611/v1/efb59ed2-96e8-44fe-b1c4-504e56e53bb5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Reverse shoulder arthroplasty versus locking plate fixation for proximal humeral fracture dislocations in elderly patients: study protocol for a randomized controlled trial","fulltext":[{"header":"Background ","content":"\u003cp\u003eProximal humeral fractures are common fractures in the elderly population, and their incidence is anticipated to increase significantly due to the rising life expectancy [1-3]. A small subset of these fractures can be concurrent with a shoulder dislocation, which often results in more severe pain and functional impairment than isolated fractures. Moreover, those dislocations (except those combined with isolated greater/lesser tuberosity fractures) always\u0026nbsp;cannot be reduced manually, as a result, necessitate a surgical intervention [4].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOpen reduction and internal fixation with a locking plate (LP), which involves plates and screws designed to conform to the anatomy of the proximal humerus to facilitate fracture healing and restore joint function, is a common surgical technique for treating proximal humeral fracture dislocations.\u0026nbsp;A systematic review study indicated that LP treatment for patients with proximal humeral fracture dislocations although achieve reasonable functional outcomes in general, the rates of humeral head necrosis and reoperation are relatively high [5]. From another perspective, proximal humeral fracture dislocations in the elderly can also be treated with shoulder replacement, and in most cases, reverse shoulder replacement (RSA) is applied. Several studies reported RSA could yield satisfactory results in these patients [6-8]. The rationale for RSA includes: 1) significant vascular disruption to the proximal humerus increases the incidence of humeral head necrosis after LP fixation (approximately 20%), necessitating subsequent arthroplasty [9-11]; 2) the rotator cuff, which is essential for shoulder movement, is frequently compromised in association with dislocation trauma or in elderly patients, resulting in poor shoulder function despite fracture healing after locking plate fixation [12-13] ;3) the technical demands of LP fixation for such injuries are high, making anatomical reduction challenging. Currently, there is evidence supporting that both RSA and LP can achieve favorable outcomes in the treatment of elderly patients with proximal humeral fracture dislocations [5-8].\u0026nbsp;\u0026nbsp;Although some studies, such as Joseph et al., suggest that RSA may be superior to LP\u0026mdash;citing a successful clinical outcome in an 80-year-old patient with a four-part proximal humeral fracture and subsequent dislocation, and recommending RSA over traditional LP fixation\u0026mdash;this conclusion is not strongly supported by high-level evidence [14]. Therefore, conducting a high-quality clinical trial comparing the effectiveness of LP fixation with RSA in the treatment of elderly proximal humeral fracture dislocations would be meaningful.\u003c/p\u003e\n\u003cp\u003eHere we present a protocol of a prospective, single-center, superiority randomized clinical trial to compare RSA and LP fixation in elderly patients with a proximal humeral fracture dislocation. We hypothesize that RSA provides better shoulder outcomes compared to LP fixation. The successful execution of this trial will provide clinical data to support the assessment of the effectiveness of both procedures in treating proximal humeral fracture dislocations, offering high-quality medical evidence to guide future clinical decision-making.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy setting and trial design\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study is a prospective, single-center, superiority randomized controlled trial. \u0026nbsp;Eligible participants will be randomly assigned to two groups: LP group and the RSA group. Assessments will be conducted at baseline, postoperative day 1, and at postoperative 1, 3, 6, 12, and 24 months for all participants. See participant flowchart in Figure 1. Any changes to the protocol that could impact the study's execution, patient outcomes, or safety—including modifications to study objectives, design, participant demographics, sample size, procedures, or critical administrative details—require a formal protocol amendment. Ethical approval for the study was obtained from the Ethics Committee of Shanghai Sixth People’s Hospital (2024-110). All participants will provide written informed consent before data collection begins. This trial is registered with the Chinese Clinical Trial Registry (registration number: ChiCTR\u0026nbsp;2400088249).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRecruitment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients with proximal humeral fractures presenting to the outpatient and emergency departments of our hospital will undergo screening. At this stage, frontline physicians will make the diagnosis of proximal humeral fracture dislocation by reviewing the patient’s medical history, performing a physical examination, and analyzing initial X-rays and Computed Tomography (CT) scans. The initial X-ray of the injured shoulder includes standard anteroposterior and lateral views. Once the diagnosis is confirmed, a member of the trial researchers will assess eligibility by reviewing the patient's medical history, physical examination, and imaging data within 24 hours. If the patient appears to meet the inclusion and exclusion criteria, he/she will be contacted in person or by phone for a further evaluation, during which the trial details will be explained. If the patient expresses interest in participating, the researcher will provide further explanation and written information about the study. Patients who consent to participate will be asked to sign a written informed consent form. With obtaining informed consent, the patient will be scheduled for an enhanced shoulder MRI (3.0 T, resolution 1.5, slice thickness 3 mm) examination. To be noted, if a large rotator cuff tear were found by MRI at this stage (defined as a tear with a diameter of 5 cm), the patient would be excluded according to the exclusion criteria.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEligibility criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients who meet all the inclusion criteria, and none of the exclusion criteria will be eligible.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eInclusion criteria:\u003c/em\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1.Age 65 to 85 years (including 65 and 85 years);\u003c/p\u003e\n\u003cp\u003e2.Unilateral proximal humeral fractures combined with a shoulder dislocation, (Neer type VI) based on injury history, physical examination, X-rays, and CT scans;\u003c/p\u003e\n\u003cp\u003e3.Patients with a general condition that permits them to tolerate surgery;\u003c/p\u003e\n\u003cp\u003e4.Acute fracture (within 3 weeks of injury);\u003c/p\u003e\n\u003cp\u003e5.Patients who provide written consent to participate.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eExclusion criteria:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e1.Shoulder dislocations with isolated greater/lesser tuberosity fractures;\u003c/p\u003e\n\u003cp\u003e2.MRI-confirmed large rotator cuff tears(a tear with a diameter of 5 cm) [15];\u003c/p\u003e\n\u003cp\u003e3.Patients with axillary nerve injury or deltoid muscle strength of grade 4(based on Medical Research Council scale) or lower on the affected side [16];\u003c/p\u003e\n\u003cp\u003e4.Patients with contraindications to MRI (e.g., pacemakers, claustrophobia);\u003c/p\u003e\n\u003cp\u003e5.Gustilo-Anderson type III open fractures or open fractures with vascular or nerve injuries;\u003c/p\u003e\n\u003cp\u003e6.Patients with pathological fractures, such as those associated with tumors, osteomalacia, osteomyelitis, or simple bone cysts；\u003c/p\u003e\n\u003cp\u003e7.Patients with a history of previous trauma or surgery to the ipsilateral upper limb;\u003c/p\u003e\n\u003cp\u003e8.Patients with psychiatric disorders or who do not understand Chinese and are unable to comprehend and independently complete the questionnaire.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAllocation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAn independent staff member, who is not involved in the trial's implementation, will generate the randomization index using an encrypted Electronic Data Capture (EDC) system. The randomization will use a 1:1 ratio (RSA group: LP group) with randomly sized blocks (block sizes of 4, 6, or 8) and will be stratified based on the Neer fracture classification (two-part, three-part, or four-part fractures). No one except this independent staff member will have access to the randomization results. Once the patients sign the written informed consent and complete the baseline assessment, they will be assigned a unique trial number. The researcher assisting with the baseline assessment will notify the staff member responsible for randomization to proceed with the enrollment. The staff member generating the randomization will then inform the surgical team and the patient of the randomization results at least 24 hours prior to surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBlinding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGiven the nature of the surgical intervention, blinding of participants or clinicians who perform the surgery is not possible. The researcher performing the imaging evaluations also will not be blinded. The trial statisticians analyzing the data and the clinicians conducting the functional follow-up assessments will be blinded. We will ensure that the clinicians conducting the functional follow-up assessments are blinded using the following procedure: researchers will take photographs of the patients to document shoulder function (as shown in Figure 2). All photos will be anonymized and collected for centralized evaluation after the completion of all follow-ups. The centralized evaluation will be conducted by two independent reviewers during a dedicated reading session. After the completion of the statistical analysis, the statistician and the clinicians conducting the functional follow-up assessments will be unblinded.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eProcedure prior surgery\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAfter enrollment, relevant baseline information of the included patients will be recorded: age(year), sex(male/female)\u0026nbsp;height(cm), weight(kg), education level (no formal education/primary education/secondary education/vocational education/\u0026nbsp;higher education), marital status(unmarried/married), dominant hand(left/right), smoking and alcohol history, presence of comorbidities, cortical thickness of the proximal humerus(mm), Neer fracture classification and AO/OTA 2018 classification [17]. The cortical thickness of the proximal humerus will be measured using the Tingart index method to assess the patients’ osteoporosis status [18]. Additionally, an immediate pain assessment will be conducted using the Visual Analog Scale(VAS) score, and baseline shoulder X-ray, CT-scan and MRI examinations will be performed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInterventions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eRSA\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eRSA modifies the conventional anatomy of the shoulder's ball-and-socket joint by positioning the humeral head (the 'ball') in the glenoid (the 'socket') and vice versa, effectively stabilizing the center of rotation of the glenohumeral joint, similar to the function of a healthy rotator cuff [19]. The surgeon and the patient in this group will jointly decide which type of reverse shoulder prosthesis to use prior to surgery, either the inlay (Trabecular Metal® Reverse Shoulder System, Zimmer Biomet, USA) or the onlay (Comprehensive® Reverse Shoulder System, Zimmer Biomet, USA). During the procedure, usually a biologic prosthesis will be used without bone cement, and bone cement will only be considered for reinforcement if instability or loosening of the prosthesis is observed. The long head of the biceps tendon will be cut and fixed during surgery, either with an anchor or sutured to the conjoint tendon. Both the greater and lesser tuberosities, as well as the rotator cuff, are reconstructed during the procedure. The implanted prosthesis and the location of the tuberosities will be confirmed and documented before the end of the operation by intraoperative fluoroscopic films, and then wound will be irrigated and closed in layers.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eLP \u0026nbsp;fixation\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eLP fixation is a commonly used surgical technique for the treatment of proximal humeral fractures. The primary goal of this operation is to achieve anatomic fracture reduction and fixation. Patient will be placed in a beach-chair position under general anesthesia. The deltopectoral approach will be used. Tuberosity fragments (if exist) will be re-connected to the rotator cuff using nonabsorbable sutures to promote reduction, and the sutures will be attached on the looking plate afterwards. Rotator cuff tears (if exist) will be sutured at the same time. After fracture reduction, K-wires are used for temporary fixation, and a C-arm X-ray machine will be used to ensure reduction. A locking plate (Philos, Synthes®, Switzerland) will be placed on the lateral to the bicipital groove once the reduction is satisfactory. The superior part of the locking plate will be placed no higher than 5 mm below the top of the greater tuberosity. Screws will be inserted afterwards. Next, final fracture fixations will be checked and documented by the intraoperative fluoroscopic films; the wound will then be irrigated and closed in layers.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRehabilitation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConduct rehabilitation interventions for patients following standardized guideline procedures [20-22]. Postoperative management requires patients to wear either an abduction-neutral brace or an abduction-external rotation brace for 4 to 6 weeks, contingent upon whether the fracture is associated with dislocation. Weight-bearing on the affected limb is strictly prohibited during the initial 6 weeks following surgery. In the first 0–3 days of hospitalization, patients are guided to perform active range-of-motion (AROM) exercises for the elbow and wrist, engage in pendulum exercises, and apply ice therapy for pain and inflammation control. Prior to the first postoperative follow-up, scheduled within 4 weeks, patients are expected to adhere to a home-based rehabilitation protocol provided by the Physiotherapist. This rehabilitation plan includes passive shoulder flexion and abduction exercises restricted to 90 degrees, passive external rotation limited to 20 degrees, isometric contractions targeting the forearm muscles, and scapular mobility exercises. Between the third- and fourth-weeks post-surgery, patients gradually transition from passive range-of-motion (PROM) exercises to active-assisted range-of-motion (AAROM) exercises, performed in a supine position.\u003c/p\u003e\n\u003cp\u003eFollowing the first postoperative follow-up, the orthopedic surgeon and rehabilitation therapist collaboratively determine the next phase of rehabilitation. During the second- and third-months post-surgery, patients progress from AAROM to full AROM exercises for the shoulder. Isometric exercises for the shoulder muscles are incrementally advanced to isotonic resistance training. Depending on the patient’s clinical condition, physical modalities and manual therapy may be incorporated into the rehabilitation process. After the third postoperative month, therapeutic exercises and manual therapy specifically addressing shoulder stability and flexibility are conducted under the therapist’s guidance. The comprehensive rehabilitation plan is detailed in Figure 3.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFollow-up measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe surgical information of the patients will be recorded: time from injury to surgery (hours), surgery date, operating surgeon (name), duration of surgery (minutes), and intraoperative blood loss (ml).\u003c/p\u003e\n\u003cp\u003ePostoperative follow-up will be conducted at 1 day (in the ward), 1 month, 3 months, 6 months, 12 months, and 24 months after surgery, in a designated follow-up room or outpatient orthopedic clinics. During each follow-up, the patient will meet with an orthopedic physician for disease-related consultation and to receive imaging examinations. Additionally, the patient will meet with a researcher in a designated follow-up room, where the researcher will deliver questionnaires and take photographs to assess shoulder functions. The data collection timetable is outlined in Table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOutcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe primary outcome is the Constant-Murley Score (CMS) at 1 year postoperatively, which includes four subscales: pain (15 points), activities of daily living (20 points), strength (25 points), and range of motion (40 points) [23]. The total score ranges from 0 to 100, with higher scores indicating better functional outcomes. The range of motion section of the CMS will be independently assessed by two reviewers under blinded conditions. The final score will be obtained by averaging the scores assessed by the two reviewers.\u003c/p\u003e\n\u003cp\u003eSecondary outcomes will include:\u003c/p\u003e\n\u003cp\u003e1.changes in VAS scores for pain (ranging from 0 to 100, with higher scores indicating greater pain severity) at postoperative days 1, 1 month, 3 months, 6 months, 12 months, and 24 months [24];\u003c/p\u003e\n\u003cp\u003e2.changes in CMS at postoperative 1 month, 3 months, 6 months, and 24 months;\u003c/p\u003e\n\u003cp\u003e3.changes in Disabilities of the Arm Shoulder and Hand questionnaire(QuickDASH) scores (ranging from 0 to 100, with higher scores indicating worse shoulder function) at postoperative 1 month, 3 months, 6 months, 12 months, and 24 months [25];\u003c/p\u003e\n\u003cp\u003e4.changes in American Shoulder and Elbow Surgeons (ASES) scores (ranging from 0 to 100, with higher scores indicating better shoulder function) at postoperative 1 month, 3 months, 6 months, 12 months, and 24 months [26];\u003c/p\u003e\n\u003cp\u003e5.changes in EuroQol-5 Dimension (EQ-5D) quality of life scores at postoperative 1 month, 3 months, 6 months, 12 months, and 24 months;\u003c/p\u003e\n\u003cp\u003e6.changes in shoulder range of motion (ROM) testing scores (ranging from 0 to 40, with higher scores indicating better range of motion) at postoperative 1 month,\u0026nbsp;\u003c/p\u003e\n\u003cp\u003emonths, 6 months, 12 months, and 24 months;\u003c/p\u003e\n\u003cp\u003e7.MRI evaluation of humeral head avascular necrosis (yes/no) in the locking plate group at 12 and 24 months postoperatively [27];\u003c/p\u003e\n\u003cp\u003e8.incidence of complications on postoperative days 1, 1 month, 3 months, 6 months, 12 months, and 24 months;\u003c/p\u003e\n\u003cp\u003e9.use of co-medications or co-treatments at postoperative days 1, 1 month, 3 months, 6 months, 12 months, and 24 months;\u003c/p\u003e\n\u003cp\u003e10.adverse event (including serious adverse events) on postoperative days 1, 1 month, 3 months, 6 months, 12 months, and 24 months;\u003c/p\u003e\n\u003cp\u003e11.surgical quality: determined upon discussion within two senior orthopedic surgeons based on the intraoperative fluoroscopic films (3 levels: poor/acceptable/satisfactory). If the evaluation result is ‘poor’ or ‘acceptable’, the reasons for the assessment will be documented.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSample size\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe calculated the sample size based on the primary outcome (CMS). Since there have been no prior prospective clinical trials specifically targeting elderly patients with proximal humeral fracture dislocation, we used retrospective study evidence and data from similar populations in previous prospective studies [28-29]. The standard deviation of the CMS for both groups at 1 year postoperatively is assumed to be 16, and the minimum clinically important difference (MCID) between groups is set at 10 points. With a power of 80% and a significance level (α) of 0.05, the calculated required sample size is 42 patients per group. To account for an anticipated loss to follow-up rate of 20%, 53 patients will be enrolled in each group [28,29].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eBaseline Demographic Data\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe baseline demographic data for both groups will be presented as means (standard deviations) or counts (percentages). Analysis will be done based on an intention-to-treat (ITT) principle. All the patients who have been randomized will be included in analysis and be grouped by the results of randomization. Significance level is set at 0.05. The data analyst will be blinded for treatment allocations.\u003c/p\u003e\n\u003cp\u003eThe CMS will be analyzed using a linear mixed model with repeated measures to calculate the inter-group differences over time. The model structure will be selected based on the lowest Akaike Information Criterion (AIC). Fixed effects will include time and the interaction between time and group, while baseline CMS and the random stratification variable (i.e., Neer fracture type) will be included as covariates. Inter-group mean differences and their 95% confidence intervals will be calculated at each time point, with the inter-group mean difference at the 1-year postoperative follow-up serving as the primary outcome. In the event of baseline demographic imbalances between the two treatment groups post-randomization, and if the researchers determine that these variables are significantly associated with the outcome measures (defined as differences exceeding 10%), sensitivity analyses will be performed to incorporate and adjust for these variables in the statistical analysis model.\u003c/p\u003e\n\u003cp\u003eThe same linear mixed model with repeated measures will be applied to analyze inter-group differences for continuous variables among the secondary outcomes at each follow-up time point. Postoperative complication rates will be described. If the complication rates exceed 10% in both groups at the 2-year follow-up, a generalized linear model will be used to compare overall complication rates between the two groups. Adverse events and co-treatments will be reported descriptively without statistical analysis.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eMissing values\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eMissing values may arise from incomplete questionnaires or loss to follow-up. Although linear mixed models account for missing data, results may become invalid when a significant proportion of values are missing (\u0026gt;5%, rule of thumb) [30]. Additionally, the assumption of missing values completely at random may not hold [31]. To assess the robustness of our findings, a sensitivity analysis using multiple imputations will be conducted.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eExploratory subgroup analysis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003ePredefined exploratory subgroup analyses will be performed to assess the interaction between baseline Neer fracture classification (i.e., the random stratification factor: two-part, three-part, and four-part fractures) and the primary outcome measures between the two groups.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eProximal humeral fractures are prevalent among the elderly and are anticipated to increase due to rising life expectancy. A subset of these fractures occurs concurrently with shoulder dislocations, leading to more severe pain and functional impairment. While current treatment options include internal locking plate fixation and reverse shoulder arthroplasty, there is a lack of high-quality trials directly comparing the effectiveness of these approaches in elderly patients with proximal humeral fracture dislocations. This trial is a prospective, single-center, superiority randomized controlled trial designed to compare the clinical effectiveness of reverse shoulder arthroplasty and locking plate fixation in elderly patients (aged 65 to 85 years) with proximal humeral fracture dislocations.\u003c/p\u003e\n\u003cp\u003eThis trial has several advantages. First, it is the first randomized controlled trial to compare RSA and LP fixation for the treatment of proximal humeral fracture dislocations in elderly patients. Second,\u0026nbsp;we preemptively control for the confounding factor of fracture classification by using stratified block randomization. Third, our follow-up duration extends to 2 years, which not only allows for the assessment of patients\u0026apos; functional recovery at different postoperative time points, providing insight into the continuity and stability of recovery, but also helps in capturing potential long-term complications, such as humeral head avascular necrosis in the LP group.\u003c/p\u003e\n\u003cp\u003eThis study also has limitations. For example, this study is a single-center study, which may have limitations in sample representativeness compared to multi-center studies. However, our hospital, as the National Center for Orthopedics, receives patients from across the country. Given the low incidence and complexity of the injury under investigation, most hospitals refer such cases to our center. Therefore, the sample in this study is expected to be relatively representative. Furthermore, designing a multicenter study may be challenging, as other centers may struggle to recruit appropriate patients. Another disadvantage is the inevitable lack of blinding. Since the intervention involves surgical treatment, blinding of participants or clinicians performing the surgery is not possible. However, we have adhered to the principle of blinding as much as possible. For instance, the trial statisticians analyzing the data and the clinicians conducting the functional follow-up assessments will remain blinded.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn conclusion, the results of this trial are expected to provide high-quality evidence to guide clinical practice in the use of LP fixation and RSA for elderly proximal humeral fracture dislocations.\u003c/p\u003e"},{"header":"Trial status ","content":"\u003cp\u003eThe first patient was enrolled on 19 Aug 2024; enrolment is anticipated to complete by 1st Aug 2028. Approximately 106 patients are expected to be enrolled.\u0026nbsp;\u003c/p\u003e"},{"header":"List of abbreviations","content":"\u003cp\u003eLP \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Locking plate\u003c/p\u003e\n\u003cp\u003eRSA \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Reverse shoulder arthroplasty\u003c/p\u003e\n\u003cp\u003eRCT \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Randomized controlled trial\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCMS \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Constant-Murley score\u003c/p\u003e\n\u003cp\u003eQuickDASH \u0026nbsp; \u0026nbsp; \u0026nbsp; Quick version of Disabilities of the Arm Shoulder and Hand\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eASES \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;American Shoulder and Elbow Surgeons\u003c/p\u003e\n\u003cp\u003eVAS \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Visual Analog Scale\u003c/p\u003e\n\u003cp\u003eEDC \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Electronic Data Capture\u003c/p\u003e\n\u003cp\u003eROM \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Shoulder range of motion\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMCID \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Minimum clinically important difference\u003c/p\u003e\n\u003cp\u003eITT \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Intention-to-treat\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participat\u003c/strong\u003e\u003cstrong\u003ee\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical approval for the study was obtained from the Ethics Committee of Shanghai Sixth People\u0026rsquo;s Hospital (2024-110). All participants will provide written informed consent before data collection begins. This trial is registered with the Chinese Clinical Trial Registry (registration number: ChiCTR 2400088249). The patients enrolled provided written informed consent to participate in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe patients who were enrolled provided written informed consent for the publication of their data for scientific purposes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe institution of one or more of authors (YFC,QKW) has received, during the study period, funding from The Institutional Research Project of Shanghai Sixth People\u0026apos;s Hospital (ynts202402) and the Municipal\u0026nbsp;Hospital Newly‐developing Cutting‐edge Technologies Joint\u0026nbsp;Research\u0026nbsp;Program of Shanghai Shenkang\u0026nbsp;Hospital\u0026nbsp;Development Center(SHDC12021117).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors confirm that they made the following contributions to the paper. Study conception and design: first author; acquisition of data: all authors; analysis and interpretation of data: all authors; draft manuscript preparation and critically revisiting the manuscript for intellectual content: all authors. All authors reviewed the results and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; information\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003e Department of Orthopaedics, Shanghai Sixth People\u0026apos;s Hospital, Shanghai, China.\u0026nbsp; \u0026nbsp;\u003csup\u003e2\u003c/sup\u003e National Center for Orthopaedics, Shanghai Sixth People\u0026apos;s Hospital, Shanghai, China.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e3\u003c/sup\u003e Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eCourt-Brown CM, Duckworth AD, Clement ND, et al. Fractures in older adults. A view of the future? Injury. 2018 Dec;49(12):2161-2166.\u003c/li\u003e\n\u003cli\u003eDauwe J, Danker C, Herteleer M, et al. Proximal humeral fracture osteosynthesis in Belgium: a retrospective population-based epidemiologic study. Eur J Trauma Emerg Surg. 2022 Dec;48(6):4509-4514.\u003c/li\u003e\n\u003cli\u003eRoux A, Decroocq L, El Batti S, et al. Epidemiology of proximal humerus fractures managed in a trauma center. Orthop Traumatol Surg Res. 2012 Oct;98(6):715-9.\u003c/li\u003e\n\u003cli\u003eKelly BJ, Myeroff CM. Reverse Shoulder Arthroplasty for Proximal Humerus Fracture. Curr Rev Musculoskelet Med. 2020 Apr;13(2):186-199.\u003c/li\u003e\n\u003cli\u003eMiltenberg B, Masood R, Katsiaunis A, et al. Fracture dislocations of the proximal humerus treated with open reduction and internal fixation: a systematic review. J Shoulder Elbow Surg. 2022 Oct;31(10):e480-e489\u003c/li\u003e\n\u003cli\u003eLin CC, Karlin E, Boin MA, et al. Operative Treatment of Proximal Humeral Fractures with Reverse Total Shoulder Arthroplasty in Patients \u0026ge;65 Years Old: A Critical Analysis Review. JBJS Rev. 2022 May 1;10(5).\u003c/li\u003e\n\u003cli\u003eMurray IR, Amin AK, White TO, et al. Proximal humeral fractures: current concepts in classification, treatment and outcomes. J Bone Joint Surg Br. 2011 Jan;93(1):1-11.\u003c/li\u003e\n\u003cli\u003ePadegimas EM, Nicholson TA, Chang G, et al. Outcomes of open reduction and internal fixation of proximal humerus fracture dislocations. J Shoulder Elbow Surg. 2021 Oct;30(10):2331-2335.\u003c/li\u003e\n\u003cli\u003eGreiner S, K\u0026auml;\u0026auml;b MJ, Haas NP, et al. Humeral head necrosis rate at mid-term follow-up after open reduction and angular stable plate fixation for proximal humeral fractures. Injury. 2009 Feb;40(2):186-91.\u003c/li\u003e\n\u003cli\u003ePadegimas EM, Nicholson TA, Chang G, et al. Outcomes of open reduction and internal fixation of proximal humerus fracture dislocations. J Shoulder Elbow Surg. 2021 Oct;30(10):2331-2335.\u003c/li\u003e\n\u003cli\u003eRoddy E, Kandemir U. High rate of avascular necrosis but excellent patient-reported outcomes after open reduction and internal fixation (ORIF) of proximal humerus fracture dislocations: should ORIF be considered as primary treatment? J Shoulder Elbow Surg. 2023 Oct;32(10):2097-2104.\u003c/li\u003e\n\u003cli\u003eMeinberg EG, Agel J, Roberts CS, et al. Fracture and Dislocation Classification Compendium-2018. J Orthop Trauma. 2018 Jan;32 Suppl 1:S1-S170.\u003c/li\u003e\n\u003cli\u003eGreen M, Whetter R, Al-Dadah O. Proximal humerus fractures and shoulder dislocations: Prevalence of concomitant rotator cuff tear[J]. Journal of Orthopaedics, Trauma and Rehabilitation, 2023, 30(1): 22104917221101409.\u003c/li\u003e\n\u003cli\u003eLabrum JT 4th, Kuttner NP, Atwan Y, et al. Fracture Dislocations of the Glenohumeral Joint. Curr Rev Musculoskelet Med. 2023 Aug;16(8):346-357. \u003c/li\u003e\n\u003cli\u003eL\u0026auml;dermann A, Denard PJ, Collin P. Massive rotator cuff tears: definition and treatment. Int Orthop. 2015 Dec;39(12):2403-14.\u003c/li\u003e\n\u003cli\u003eConde RM, de Almeida Pereira Pena L, do Nascimento Elias AH, et al. Inter-rater reliability of the Rasch-modified medical research council scoring criteria for manual muscle testing in neuromuscular diseases. J Peripher Nerv Syst. 2023 Mar;28(1):119-124.\u003c/li\u003e\n\u003cli\u003eMeinberg EG, Agel J, Roberts CS, et al. Fracture and Dislocation Classification Compendium-2018. J Orthop Trauma. 2018 Jan;32 Suppl 1:S1-S170.\u003c/li\u003e\n\u003cli\u003eTingart MJ, Apreleva M, von Stechow D, et al. The cortical thickness of the proximal humeral diaphysis predicts bone mineral density of the proximal humerus. J Bone Joint Surg Br. 2003;85:611-617.\u003c/li\u003e\n\u003cli\u003eGrammont PM, Baulot E. Delta shoulder pros thesis for rotator cuff rupture. Orthopedics 1993;16:65-8.\u003c/li\u003e\n\u003cli\u003eHandoll HH, Ollivere BJ. Interventions for treating proximal humeral fractures in adults. Cochrane Database Syst Rev. 2010 Dec 8;(12):CD000434. \u003c/li\u003e\n\u003cli\u003e\u0026Oslash;stergaard HK, Launonen AP, Toft M, et al. Physiotherapist-supervised exercises versus unsupervised home-based exercises after nonsurgically treated proximal humerus fracture: a multicenter randomized controlled trial. J Shoulder Elbow Surg. 2024 May;33(5):994-1003. \u003c/li\u003e\n\u003cli\u003eSchnackers MLAP, van Horn YY, Meys GHH, et al. Evidence-based rehabilitation therapy following surgery for (peri-)articular fractures: A systematic review. J Rehabil Med. 2019 Oct 4;51(9):638-645.\u003c/li\u003e\n\u003cli\u003eConstant CR. An evaluation of the Constant-Murley shoulder assessment. J Bone Joint Surg Br. 1997 Jul;79(4):695-6.\u003c/li\u003e\n\u003cli\u003eHawker GA, Mian S, Kendzerska T, et al. Measures of adult pain: Visual Analog Scale for Pain (VAS Pain), Numeric Rating Scale for Pain (NRS Pain), McGill Pain Questionnaire (MPQ), Short-Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS), Short Form-36 Bodily Pain Scale (SF-36 BPS), and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP). Arthritis Care Res (Hoboken). 2011 Nov;63 Suppl 11:S240-52.\u003c/li\u003e\n\u003cli\u003eBeaton DE, Wright JG, Katz JN, et al. Development of the QuickDASH: comparison of three itemreduction approaches. J Bone Joint Surg Am 2005;87:1038-46.\u003c/li\u003e\n\u003cli\u003eRichards RR, An KN, Bigliani LU, et al. A standardized method for the assessment of shoulder function. J Shoulder Elbow Surg. 1994 Nov;3(6):347-52.\u003c/li\u003e\n\u003cli\u003eCehelyk EK, Stull JD, Patel MS, et al. Humeral Head Avascular Necrosis: Pathophysiology, Work-up, and Treatment Options. JBJS Rev. 2023 Jun 27;11(6).\u003c/li\u003e\n\u003cli\u003eFraser AN, Bj\u0026oslash;rdal J, Wagle TM, et al. Reverse Shoulder Arthroplasty Is Superior to Plate Fixation at 2 Years for Displaced Proximal Humeral Fractures in the Elderly: A Multicenter Randomized Controlled Trial. J Bone Joint Surg Am. 2020 Mar 18;102(6):477-485. \u003c/li\u003e\n\u003cli\u003eRobinson CM, Khan LA, Akhtar MA. Treatment of anterior fracture-dislocations of the proximal humerus by open reduction and internal fixation. J Bone Joint Surg Br. 2006 Apr;88(4):502-8.\u003c/li\u003e\n\u003cli\u003eJakobsen JC, Gluud C, Wetterslev J, et al. When and how should multiple imputation be used for handling missing data in randomised clinical trials - a practical guide with flowcharts. BMC Med Res Methodol. 2017 Dec 6;17(1):162.\u003c/li\u003e\n\u003cli\u003eIbrahim JG, Molenberghs G. Missing data methods in longitudinal studies: a review. Test (Madr) 2009;18(1):1-43. doi: 10.1007/s11749-009-0138-x.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Table 1","content":"\u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003eFollow-up measurements.\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"602\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTime point\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ebaseline\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003ed\u003c/strong\u003e\u003cstrong\u003eay\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003em\u003c/strong\u003e\u003cstrong\u003eonth\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003em\u003c/strong\u003e\u003cstrong\u003eonth\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e6\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003em\u003c/strong\u003e\u003cstrong\u003eonth\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e12\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003em\u003c/strong\u003e\u003cstrong\u003eonth\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e24 m\u003c/strong\u003e\u003cstrong\u003eonth\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eGeneral Information\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eSurgical Information\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eConstant-Murley Score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eQuickDASH Score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eASES Score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eEQ5D Score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eVisual Analogy Score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eRange of Motion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eShoulder trauma series X-rays\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eShoulder MRI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eComplications\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003ePatient Satisfaction\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 131px;\"\u003e\n \u003cp\u003eConcomitant treatments\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ex\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\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":"journal-of-orthopaedic-surgery-and-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"josr","sideBox":"Learn more about [Journal of Orthopaedic Surgery and Research](http://josr-online.biomedcentral.com)","snPcode":"13018","submissionUrl":"https://submission.nature.com/new-submission/13018/3","title":"Journal of Orthopaedic Surgery and Research","twitterHandle":"@MSKmedBMC","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Proximal humeral fracture, Dislocation, Reverse shoulder arthroplasty, Locking plate fixation, Randomized controlled trial","lastPublishedDoi":"10.21203/rs.3.rs-6080611/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6080611/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e: Proximal humeral fractures are common injuries in the elderly population, with their incidence expected to rise due to increased life expectancy. A small subset of these fractures may be associated with dislocating forces that can result in shoulder dislocation concurrent with the fracture. For the elderly patients, proximal humeral fracture dislocation can be treated by open reduction and internal locking plate (LP) fixation or reverse shoulder arthroplasty (RSA). By now, no high-quality trials have compared the two.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e:\u003cstrong\u003e \u003c/strong\u003eThis study is a prospective, single-center, superiority randomized controlled trial (RCT) comparing RSA and LP fixation in elderly patients (aged 65 to 85 years) with a proximal humeral fracture dislocation. Eligible participants will be randomly assigned to either the RSA or LP group (1:1 ratio). Postoperative follow-up will be conducted at 1 day (in the ward), 1 month, 3 months, 6 months, 12 months, and 24 months after surgery. Primary outcome is the Constant-Murley Score at 1-year postoperatively. Secondary outcomes include short version of Disabilities of the Arm Shoulder and Hand questionnaire score, American Shoulder and Elbow Surgeons \u0026nbsp;score, Visual Analog Scale score, EuroQol-5 Dimension score, range of motion, strength and postoperative complications.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDiscussion\u003c/strong\u003e: This trial is the first RCT comparing RSA with LP fixation for proximal humeral fracture dislocations in elderly patients. The results of this study will provide high-quality evidence to guide clinical practice.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial Registration\u003c/strong\u003e: China Clinical Trials Registry No. ChiCTR2400088249.\u003c/p\u003e","manuscriptTitle":"Reverse shoulder arthroplasty versus locking plate fixation for proximal humeral fracture dislocations in elderly patients: study protocol for a randomized controlled trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-06 13:39:56","doi":"10.21203/rs.3.rs-6080611/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-05-06T12:07:57+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-01T22:26:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"230817053148713095029898055940257629397","date":"2025-05-01T15:29:13+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-29T12:09:54+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-29T10:00:24+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Orthopaedic Surgery and Research","date":"2025-04-29T01:15:09+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-orthopaedic-surgery-and-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"josr","sideBox":"Learn more about [Journal of Orthopaedic Surgery and Research](http://josr-online.biomedcentral.com)","snPcode":"13018","submissionUrl":"https://submission.nature.com/new-submission/13018/3","title":"Journal of Orthopaedic Surgery and Research","twitterHandle":"@MSKmedBMC","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"cd19da26-51de-4e91-8680-4fb47f62ceaa","owner":[],"postedDate":"May 6th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-06-09T16:00:05+00:00","versionOfRecord":{"articleIdentity":"rs-6080611","link":"https://doi.org/10.1186/s13018-025-05982-y","journal":{"identity":"journal-of-orthopaedic-surgery-and-research","isVorOnly":false,"title":"Journal of Orthopaedic Surgery and Research"},"publishedOn":"2025-06-04 15:57:09","publishedOnDateReadable":"June 4th, 2025"},"versionCreatedAt":"2025-05-06 13:39:56","video":"","vorDoi":"10.1186/s13018-025-05982-y","vorDoiUrl":"https://doi.org/10.1186/s13018-025-05982-y","workflowStages":[]},"version":"v1","identity":"rs-6080611","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6080611","identity":"rs-6080611","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}