The Modified Squat and Smile Test: Correlation with Fracture Union in Long Bone Fractures of the Lower Limb

The Modified Squat and Smile Test: Correlation with Fracture Union in Long Bone Fractures of the Lower Limb | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The Modified Squat and Smile Test: Correlation with Fracture Union in Long Bone Fractures of the Lower Limb Delroy Arnolds, Sithombo Maqungo, Michael Held, Nando Ferreira, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7373072/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 19 Nov, 2025 Read the published version in European Journal of Orthopaedic Surgery & Traumatology → Version 1 posted 12 You are reading this latest preprint version Abstract Purpose Assessing fracture union remains a significant challenge in low-resource settings, such as those across Sub-Saharan Africa. The original Squat and Smile Test was developed as a potential surrogate measure for lower limb fracture union, aiming to reduce reliance on follow-up radiographs in environments with limited access to imaging. We evaluated the correlation between the (blinded) Modified Squat and Smile Test (MSST) and fracture union following intramedullary nailing of lower limb long bone fractures. Methods We performed a retrospective review of prospectively collected data from the HIV in Orthopaedic Skeletal Trauma (HOST) study. Results A total of 180 patients with recorded MSST data were included in the analysis. There was no significant correlation between the MSST total score, or its individual domains (squat, support, and smile), and radiological evidence of fracture union. However, health-related quality of life measures (EQ-5D and Disability Rating Index (DRI)) showed a significant positive correlation with the total MSST score, as well as with the squat and smile domains (p < 0.05). No significant correlation was found between the support domain and these measures. Conclusion The MSST and its individual domains did not correlate with radiological fracture union following intramedullary nailing of lower limb fractures. However, the test showed significant positive associations with patient-reported outcome measures, suggesting potential utility in assessing functional recovery. Further prospective research is needed to validate the MSST and to explore its role in both clinical assessment and follow-up care in resource-limited settings. fracture union intramedullary nailing lower limb patient-reported outcomes outcome Figures Figure 1 Figure 2 Introduction Lower limb long bone fractures are debilitating injuries and are more common in low-to-middle-income countries (LMIC) [ 1 ]. In addition to the high burden of these injuries, many LMIC have limited access to resources such as radiological imaging [ 2 ]. Assessing fracture union is a critical component of orthopaedic care and is typically performed through clinical examination and confirmed radiologically with x-rays. However, this process poses significant challenges in resource-constrained settings, where patients may be unable to attend regular follow-up appointments and radiographic imaging is often unavailable or prohibitively expensive [ 3 ]. An ideal fracture union assessment tool should be quick and easy to use, as well as accurate and cost-effective. It must also have good inter-rater and intra-rater reliability. The ability to use this tool remotely would be of further benefit, especially in resource-constrained environments [ 4 ]. A simple functional outcome test to assess mobility and stability of lower limb joints involves assessing a patient’s ability to squat [ 5 ]. A squat involves lowering the hips from a standing position while bending the knee and ankle joints and returning to a standing position [ 6 ]. This action is one of the most basic functional movements that is required to perform activities of daily living and religious practices. The Squat and Smile test (SST) was developed as a clinical measure of weight bearing and range of motion (ROM) in LMICs and has been shown to be a possible surrogate for confirming fracture union in lower limb fractures, without the need for radiological imaging [ 7 ]. The SST involves assessing a patient performing a deep squat, with as little support as possible, and observing their facial expression. The rationale is: that if a patient can hold themselves in the squat position and smile, it shows that they have returned to full function. In addition, deep knee bend shows restored ROM. The squat position mechanically stresses the fracture site, testing that bone fragments have healed. It is suggested that the patient’s smile indicates that they are pain-free [ 8 ]. However, a key limitation of the test is that the facial expression component has been shown to correlate poorly with actual fracture union, likely due to its subjective nature [ 7 ]. In this study, we used a modified SST hereafter referred to as the MSST, in which the 'smile' component was adapted to increase objectivity. The primary aim was to evaluate the correlation between the MSST and radiographic fracture union following intramedullary nailing of lower limb long bone fractures. Secondary aims included comparison of individual MSST component scores with fracture union, as well as with the Radiographic Union Score for Tibial fractures (RUST), the EuroQol-5 Dimension (EQ-5D) health-related quality of life score, and the Disability Rating Index (DRI). Materials and Methods Study design We performed a retrospective review of data from the HIV in Orthopaedic Skeletal Trauma (HOST) study database, a multi-centre prospective observational study (NCT03131947) involving patients aged > 18 years with fresh (within two weeks of injury), closed and open tibia and femur fractures who underwent intramedullary (IM) nailing for fracture fixation [ 9 ]. Data collection for the HOST study took place between September 2017 and December 2018. Study sample We included data from patients in the HOST study who had their MSST recorded and videoed during follow-up appointments following IM nailing for femur and/or tibia shaft fractures. Patients without available video footage of the MSST were excluded. Additionally, patients who had undergone contralateral or ipsilateral lower limb IM nailing were excluded to eliminate potential confounding factors affecting functional assessment. Informed consent was obtained from all participants for both study participation and video recording. Data collection Data collected from the HOST study database included patient demographic information, MSST overall test scores, sub scores, fracture union as assessed by the RUST, EQ-5D, and DRI scores. Additionally, we retrieved video footage of patients at their routine follow-up assessments as part of the HOST study. Clinical assessment, x-rays, EQ-5D, DRI, MSST and RUST scores were all recorded at 6 weeks, 3 months, 6 months and 12 months post operatively. If a participant was confirmed united prior to 12 months follow up, the scores at union confirmation was used as the final score. MSST test All patients include had their MSST videoed by the study team. We assessed the ‘smile’ component of the test by asking patients to point to a picture of a facial expression that best depicts their pain level after performing a squat and by observing dynamic video footage, instead of assessing static photographs, as performed in previous studies. ( Fig. I ). The MSST test video footage for each patient was viewed by two investigators. One was an orthopaedic trainee, and one was a non-specialist. Investigators graded the squat in the following three main domains (Table I): overall squat (0 = unable to squat at all, 1 = less than 45 degrees flexion at hip, 2 hips above level of the knees, 3 = hips at level of the knees or below); the need for support (0 = unable to squat unassisted, 1 = requires support with two hands, 2 = requires support with one hand, 3 = no support needed); and smile (1 = sad/frown, 2 = no smile, 3 = smile). The “squat” component of the score was determined to be either “Able to squat” (scores of 2 and 3 ) or “Unable to Squat”(scores of 0 and 1). Table I. (Blinded) Squat and Smile Scoring SST Domain Score Explanation Overall squat 0 Unable to squat at all 1 Less than 45 degrees of flexion at the hip 2 Hips above the level of the knees 3 Hips at the level of the knees or below The need for support 0 unable to squat unassisted 1 Requires support with two hands 2 Requires support with one hand 3 No support needed Smile 1 Sad/frown 2 No smile 3 Smile Fracture union assessments Bone healing was assessed using the validated radio- logical union scoring system for tibia (RUST). Delayed bone union was defined as impaired bone healing at 6 months on RUST score. Non-union was defined as either impaired bone healing at 9 months on RUST score or the need for further surgery to achieve union (RUST score ,9) before 9 months (decision made by 2 orthopedic surgeons) [ 10 – 12 ]. Two reviewers (both orthopedic surgeons), blinded to MSST score, independently assessed radiological fracture union on radiographs. In case of discrepancies in RUST scoring between the reviewers, a third reviewer (orthopedic surgeon) independently undertook a review of the radiograph to determine the final outcome. Statistical analysis Descriptive statistics were used to summarize participants’ demographic and clinical characteristics. To evaluate the inter-rater reliability of the MSST, the absolute agreement intra-class correlation coefficient (ICC) and 95% confidence interval (CI) were calculated for the three SST domains (squat, support and smile). The ICC measures score reliability by comparing the variability of different scores assigned to the same participant, with the total variation across all scores and all participants. ICC values < 0.50 were categorized as “poor agreement”; 0.50 ≤ ICC < 0.75 as “moderate agreement”; 0.75 ≤ ICC < 0.90 as “good agreement” and ICC ≥ 0.90 as “excellent agreement” [ 13 ]. Fisher’s exact test was used to determine the association between fracture union (yes/no), open and closed fractures, and mechanism of injury (MOI). The Kendall rank correlation coefficient was used to determine the association between components of the MSST and age, EQ-5D, DRI and RUST scores. The difference in MSST total and sub-domain scores between the union and non-union subgroups was evaluated using the Mann-Whitney U test. All analyses were performed by an independent statistician using IBM SPSS Statistics (Version 27) and the level of significance was set at p < 0.05. Results Between September 2017 and December 2018, 638 patients underwent IM nailing of the femur and the tibia at the two study sites and were screened for eligibility. 442 IM nails in 400 patients were included in the HOST study. Of these patients, 220 were excluded because a video of MSST was not recorded. Final data analysis was performed on 180 participants ( Fig. II ). The demographic and clinical characteristics of the 180 patients are summarized in Table II . Table II. Demographic and clinical characteristics of the 180 study participants presenting with lower limb fractures. Variable Value Sex, n (%) Male 144 (80) Female 36 (20) Mean age, years (SD) 34.5 (10.6) MOI, n (%) PVA 74 (41) MVA 43 (24) GSW 31 (18) High energy fall 11 (6) Low energy fall 9 (5) Assault 5 (3) Crush (heavy machinery) 3 (2) Blunt force trauma 3(2) Other 1 (0) Fracture type, n (%) Closed 111 (62) Open 69 (38) Location of fracture and treatment nailing type, n(%) Femur 81 (45) Right 51 (63) AFN (antegrade) 39 (76) RFN (retrograde) 12 (24) Left 30 (37) AFN (antegrade) 25 (83) RFN (retrograde) 5 (17) Tibia 99 (55) Right 50 (51) SPN (suprapatellar) 44 (88) IPN (infrapatellar) 6 (12) Left 49 (49) SPN (suprapatellar) 47 (96) IPN (infrapatellar) 2 (4) Union, n (%) Yes 143 (79) No 37 (21) Mean EQ-5D index, (SD) 89.69 (12) Mean DRI score, (SD) 203.5 (159) Definitions DRI, Disability Rating Index; MOI, Mechanism of Injury; GSW, Gunshot Wound; RUST, Radiological Union Score; SD, standard deviation. AFN, Antegrade Femoral Nail; IPN, Infrapatellar Nail; RFN, Retrograde Femur Nail; SPN, Suprapatellar Nail. Inter-rater reliability was excellent for the two components of the MSST scored by reviewers (Squat and Support) ( Table III ). Table III. Inter-rater reliability of MSST MSST components Mean scores ICC (95% CI) Observer 1 Observer 2 Squat 2.2 (0.9) 2.2 (0.9) 0.971 (0.96–0.98) Support 2.7 (0.7) 2.6 (0.8) 1.00 Total 7.2 (1.8) 7.2 (1.9) 0.99 (0.97–0.99) The median MSST score for fractures that were united and non-united fractures were 8 and 7 respectively. The difference was not statistically significant (p = 0.113)). There were no significant differences in MSST sub-scores between participants with or without fracture union (summarised in Table IV ). Table IV. Comparing MSST scores between patients with and without fracture union. MSST Domains Union n = 143 Non-union n = 37 p-value Mann Whitney U test (z) Cohen Effect size (r) Squat 2 (2–3) 2 (1–3) 0.235 -1.19 0.08 Smile 3 (2–3) 3 (2–3) 0.107 -1.61 0.12 Support 3 (3–3) 3 (3–3) 0.771 -0.29 0.02 Total 8 (6–9) 7 (6–8.5) 0.113 -1.59 0.12 Sensitivity and specificity was 81% and 35% respectively, while the positive and negative predicative values were 83% and 33% respectively ( Table V ). Table V. Comparing ability to squat with union/union Able to Squat (Score of 2–3) Unable to Squat (Score 0–1) Union 116 (81%) 27 (19%) 143 Non Union 24 (65%) 13 (35%) 37 Total 140 40 180 Sensitivity 116/143 x100, Specificity 13/24 x100, PPV 116/140 x100, NPPV 13/40 x100 EQ-5D had a statistically significant correlation with the total MSST score (p < 0.05), the squat domain (p < 0.01) and the smile domain (p < 0.05). EQ-5D had no correlation with the support domain. DRI had a statistically significant inverse correlation with the total MSST score (p < 0.001), squat domain (p < 0.001) and smile domain (p < 0.001). DRI had no correlation with the support domain. Age had an inverse correlation with all three components of the MSST. All these associations were statistically significant (p < 0.05). RUST score had no correlation to the total MSST score, squat domain and support domain The association between RUST and the smile component was significant (p < 0.05) ( Table VI ). Table VI. Kendall’s tau correlates with the MSST. Variable (Blinded) Squat & Smile Test Squat Support Smile Total EQ-5D score 0.16** 0.02 0.13* 0.10* DRI score -0.30*** -0.02 -0.27*** -0.26*** Age -0.25*** -0.16* -0.14* -0.25*** RUST score 0.13 0.10 0.21** 0.12 *p < 0.05. **p < 0.01. *** p < 0.001. Discussion This study aimed to determine the correlation between the (blinded) modified Squat and Smile Test (MSST) and fracture union of lower limb long bone fractures, post intramedullary nailing. We modified the smile domain of the MSST, as it was subjectively assessed and prone to physician bias. We attempted to make the smile component more objective, and we hypothesised that the modified score may correlate better with fracture healing. In our study we found no correlation between the MSST and fracture union. There are only three studies looking at the relationship between fracture union and the squat and smile, most of them from the SIGN (Surgical Implant Generation Network) Fracture Care database [ 14 – 16 ] Currently, the combination of clinical history assessment with comprehensive examination, and supplementation with radiological imaging, is used to assess fracture healing. Eliezer et al., ( 2017) was the first to assess the SST and its correlation with fracture union and found no correlation between the two [ 17 ]. In 2019, Wu et al. , defined the domains of the squat and smile test and found that the squat and support domain correlated with the need for reoperation. The most common reasons for reoperation in their study were infection (15/272) and non-union (3/272). Sciuto et al. , found the squat and smile test correlated with union, but not with the smile domain [ 14 ]. However, their cohort included paediatric patients and used a different scoring system for fracture union (REBORNE). They also used a different scoring system for the squat and smile (GAS) and not the one originally proposed. In our study, quality of health measures in the form of EQ-5D and DRI had a significant correlation with total MSST score, squat domain and smile domain. The support domain had no correlation. The smile domain of the MSST correlated with quality-of-life measures, a finding which highlights the previous subjectivity of this component and the need for patient-driven assessment tools and outcome measures. This was expected as both elements take the patient's views and scores of their overall recovery status into account. This retrospective review has several limitations. We used data from an existing dataset that determined the study population. A power calculation was not performed for analysis and the findings should therefore be interpreted with caution. Despite no standardisation of how videos were taken, our study showed good reliability of the MSST. Conclusion We found no correlation between fracture union of lower limb fractures post intramedullary nailing and the MSST, as well as its sub-scores. However, we observed a strong correlation between quality-of-life measures and the MSST, particularly in the squat and smile domains. Notably, the association between the RUST score and the smile component was significant, suggesting that if a patient can smile during the test, it may reflect a level of recovery comparable to radiographic healing. These findings highlight the potential role of the MSST in assessing functional recovery and patient-reported outcomes, rather than as a surrogate for fracture union. Further research is warranted to refine the MSST and to validate its utility in larger, prospective cohorts. Declarations Ethical Statement (Human Ethics and Consent to Participate) Ethical (REF: HREC 590/2016 (blinded) and N17/05/052 (blinded) and hospital institutional approval (blinded) for the was obtained and patient confidentiality was appropriately maintained. Informed consent was obtained from all individual participants included in the study. Funding The HOST study was funded by the Wellcome Trust Research and Training PhD Fellowship and support from AOUK Foundation. This research was supported by the NIHR (NIHR155559) using UK international development funding from the UK Government to support global health research. This study has been delivered through the National Institute for Health and Care Research (NIHR) Oxford Biomedical Research Centre (BRC). The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR or the UK government. This research was also supported by the Medical Research Council (Grant number: MR/Y00955X/1) and the NIHR Oxford Biomedical Research Centre. Author Contribution All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by DA. The first draft of the manuscript was written by DA and SMG and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Acknowledgement The authors thank all those who contributed to this research from Groote Schuur and Tygerberg Hospitals, Cape Town, South Africa. Furthermore, the authors would like to thank the significant contribution to this research by Nomsa Yekiso and Nosipho Jennifer Mncwabe. Data Availability Data cannot be shared openly but are available on request from authors. References Singaram S, Naidoo M. The physical, psychological and social impact of long bone fractures on adults: A review. Afr J Prim Health Care Fam Med [Internet]. 2019 [cited 2023 Jun 20];11(1). Available from: https://pubmed.ncbi.nlm.nih.gov/31170796/ Spiegel DA, Gosselin RA, Coughlin RR, Joshipura M, Browner BD, Dormans JP. The burden of musculoskeletal injury in low and middle-income countries: challenges and opportunities. J Bone Joint Surg Am [Internet]. 2008 [cited 2023 Jun 20];90(4):915–23. Available from: https://pubmed.ncbi.nlm.nih.gov/18381331/ Morshed S. Current Options for Determining Fracture Union. Adv Med [Internet]. 2014 [cited 2023 Jun 20];2014:1–12. Available from: https://pubmed.ncbi.nlm.nih.gov/26556422/ Kauta NJ, Groenewald J, Arnolds D, Blankson B, Omar A, Naidu P, et al. WhatsApp Mobile Health Platform to Support Fracture Management by Non-Specialists in South Africa. J Am Coll Surg [Internet]. 2020 Jan 1 [cited 2023 Jun 20];230(1):37–42. Available from: https://pubmed.ncbi.nlm.nih.gov/31672673/ Cook G, Burton L, Hoogenboom B. Pre-participation screening: the use of fundamental movements as an assessment of function - part 1. N Am J Sports Phys Ther [Internet]. 2006 May [cited 2023 Dec 1];1(2):62–72. Available from: http://www.ncbi.nlm.nih.gov/pubmed/21522216 Lubans DR, Morgan PJ, Cliff DP, Barnett LM, Okely AD. Fundamental movement skills in children and adolescents: review of associated health benefits. Sports Med [Internet]. 2010 [cited 2023 Jun 20];40(12):1019–35. Available from: https://pubmed.ncbi.nlm.nih.gov/21058749/ Wu HH, Liu M, Challa ST, Morshed S, Eliezer EN, Haonga BT, et al. Development of Squat-and-Smile Test as Proxy for Femoral Shaft Fracture-Healing in Patients in Dar es Salaam, Tanzania. J Bone Joint Surg Am [Internet]. 2019 Feb 20 [cited 2023 Jun 20];101(4):353–9. Available from: https://pubmed.ncbi.nlm.nih.gov/30801374/ Vetter TR, Heiner EJ. Discordance between patient self-reported visual analog scale pain scores and observed pain-related behavior in older children after surgery. J Clin Anesth [Internet]. 1996 [cited 2023 Aug 29];8(5):371–5. Available from: https://pubmed.ncbi.nlm.nih.gov/8832447/ Graham SM, Maqungo S, Laubscher M, Ferreira N, Held M, Harrison WJ, et al. Fracture Healing in Patients With HIV in South Africa: A Prospective Cohort Study. J Acquir Immune Defic Syndr [Internet]. 2021 Aug 15 [cited 2023 Jun 20];87(5):1214–20. Available from: https://pubmed.ncbi.nlm.nih.gov/33990496/ Çekiç E, Alici E, Yeşil M. Reliability of the radiographic union score for tibial fractures. Acta Orthop Traumatol Turc [Internet]. 2014 [cited 2023 Aug 29];48(5):533–40. Available from: https://pubmed.ncbi.nlm.nih.gov/25429579/ Panchoo P, Laubscher M, Held · Michael, Maqungo S, Ferreira N, Simpson H, et al. Radiographic union score for tibia (RUST) scoring system in adult diaphyseal femoral fractures treated with intramedullary nailing: an assessment of interobserver and intraobserver reliability. European Journal of Orthopaedic Surgery & Traumatology [Internet]. 2022;32(3):1555–9. Available from: https://doi.org/10.1007/s00590-021-03134-6 Litrenta J, Tornetta P, Mehta S, Jones C, O’Toole R V., Bhandari M, et al. Determination of Radiographic Healing: An Assessment of Consistency Using RUST and Modified RUST in Metadiaphyseal Fractures. J Orthop Trauma [Internet]. 2015 Nov 1 [cited 2023 Jun 20];29(11):516–20. Available from: https://pubmed.ncbi.nlm.nih.gov/26165265/ Koo TK, Li MY. A Guideline of Selecting and Reporting Intraclass Correlation Coefficients for Reliability Research. J Chiropr Med [Internet]. 2016 Jun 1 [cited 2023 Nov 13];15(2):155–63. Available from: https://pubmed.ncbi.nlm.nih.gov/27330520/ Sciuto D, Marzorati M, Shearer DW, Lanfranconi F. Functional assessment of long bone fracture healing in Samburu County Referral Hospital (Kenya): the squat and smile challenge. OTA Int [Internet]. 2021 Dec [cited 2023 Dec 14];4(4):e148. Available from: http://www.ncbi.nlm.nih.gov/pubmed/34765899 Alves KM, Lerner A, Silva GS, Katz JN. Surgical Implant Generation Network Implant Follow-up: Assessment of Squat and Smile and Fracture Healing. J Orthop Trauma [Internet]. 2020 Apr 1 [cited 2023 Jun 20];34(4):174–9. Available from: https://pubmed.ncbi.nlm.nih.gov/31652187/ Maharjan R, Pokharel B, Shah Kalawar RP, Rijal R, Baral D. Squat and smile assessment in predicting healing of lower limb fractures fixed with a SIGN nail. J Clin Orthop Trauma [Internet]. 2021 Aug 1 [cited 2023 Jun 20];19:34–41. Available from: https://pubmed.ncbi.nlm.nih.gov/34046298/ Eliezer EN, Haonga BT, Morshed S, Shearer DW. Predictors of Reoperation for Adult Femoral Shaft Fractures Managed Operatively in a Sub-Saharan Country. J Bone Joint Surg Am [Internet]. 2017 [cited 2023 Jun 20];99(5):388–95. Available from: https://pubmed.ncbi.nlm.nih.gov/28244909/ Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 19 Nov, 2025 Read the published version in European Journal of Orthopaedic Surgery & Traumatology → Version 1 posted Editorial decision: Revision requested 01 Sep, 2025 Reviews received at journal 30 Aug, 2025 Reviewers agreed at journal 27 Aug, 2025 Reviewers agreed at journal 23 Aug, 2025 Reviewers agreed at journal 23 Aug, 2025 Reviewers agreed at journal 22 Aug, 2025 Reviews received at journal 21 Aug, 2025 Reviewers agreed at journal 21 Aug, 2025 Reviewers invited by journal 19 Aug, 2025 Editor assigned by journal 14 Aug, 2025 Submission checks completed at journal 14 Aug, 2025 First submitted to journal 14 Aug, 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-7373072","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":506298555,"identity":"a1c5062e-c0b2-4765-82d5-d022a6d3a2a7","order_by":0,"name":"Delroy Arnolds","email":"","orcid":"","institution":"University of Cape Town","correspondingAuthor":false,"prefix":"","firstName":"Delroy","middleName":"","lastName":"Arnolds","suffix":""},{"id":506298556,"identity":"724c813a-710c-4afb-8c90-e0bb177fef11","order_by":1,"name":"Sithombo Maqungo","email":"","orcid":"","institution":"University of Cape Town","correspondingAuthor":false,"prefix":"","firstName":"Sithombo","middleName":"","lastName":"Maqungo","suffix":""},{"id":506298557,"identity":"efac06d3-4a40-4932-914e-a53a0126e39e","order_by":2,"name":"Michael Held","email":"","orcid":"","institution":"University of Cape Town","correspondingAuthor":false,"prefix":"","firstName":"Michael","middleName":"","lastName":"Held","suffix":""},{"id":506298558,"identity":"eabf304c-3947-4906-9a98-c6840fd13d08","order_by":3,"name":"Nando Ferreira","email":"","orcid":"","institution":"Stellenbosch University","correspondingAuthor":false,"prefix":"","firstName":"Nando","middleName":"","lastName":"Ferreira","suffix":""},{"id":506298559,"identity":"143e686b-7c8f-41c3-8ea9-304d25038562","order_by":4,"name":"Roopam Dey","email":"","orcid":"","institution":"University of Cape Town","correspondingAuthor":false,"prefix":"","firstName":"Roopam","middleName":"","lastName":"Dey","suffix":""},{"id":506298560,"identity":"87e1e333-bed5-4a14-ab80-2706650e02a7","order_by":5,"name":"Robyn Waters","email":"","orcid":"","institution":"University of Cape Town","correspondingAuthor":false,"prefix":"","firstName":"Robyn","middleName":"","lastName":"Waters","suffix":""},{"id":506298561,"identity":"5c6372a9-e493-46e3-ad9d-24889e340dc0","order_by":6,"name":"Maritz Laubscher","email":"","orcid":"","institution":"University of Cape Town","correspondingAuthor":false,"prefix":"","firstName":"Maritz","middleName":"","lastName":"Laubscher","suffix":""},{"id":506298562,"identity":"2cdf531e-db07-445c-bc82-b2f8e0e24d97","order_by":7,"name":"Simon Graham","email":"data:image/png;base64,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","orcid":"","institution":"University of Oxford","correspondingAuthor":true,"prefix":"","firstName":"Simon","middleName":"","lastName":"Graham","suffix":""}],"badges":[],"createdAt":"2025-08-14 10:53:45","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7373072/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7373072/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00590-025-04532-w","type":"published","date":"2025-11-19T15:59:03+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":90305554,"identity":"d8d4392a-d49f-416d-921f-729ea49bea61","added_by":"auto","created_at":"2025-09-01 09:24:09","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":57991,"visible":true,"origin":"","legend":"\u003cp\u003eSmiley face (yellow), neutral face (green) and unhappy face (blue) as emoticons patients could select to rate their pain during squatting\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7373072/v1/5da2f0cc497feb6f661044ce.jpeg"},{"id":90305596,"identity":"24a4dfa4-5fb7-4075-81e4-53f765f5f92c","added_by":"auto","created_at":"2025-09-01 09:24:15","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":110648,"visible":true,"origin":"","legend":"\u003cp\u003eStudy flow diagram. Shows the number of individuals who underwent IM nailing for fracture fixation\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7373072/v1/e80299df085551889689272c.jpg"},{"id":96650246,"identity":"56a66501-b3f5-48cd-a509-57913b32ebe2","added_by":"auto","created_at":"2025-11-24 16:10:19","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1069792,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7373072/v1/cb08d272-6b7b-41ca-be35-08c72e43c4b2.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Modified Squat and Smile Test: Correlation with Fracture Union in Long Bone Fractures of the Lower Limb","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLower limb long bone fractures are debilitating injuries and are more common in low-to-middle-income countries (LMIC) [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In addition to the high burden of these injuries, many LMIC have limited access to resources such as radiological imaging [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Assessing fracture union is a critical component of orthopaedic care and is typically performed through clinical examination and confirmed radiologically with x-rays. However, this process poses significant challenges in resource-constrained settings, where patients may be unable to attend regular follow-up appointments and radiographic imaging is often unavailable or prohibitively expensive [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eAn ideal fracture union assessment tool should be quick and easy to use, as well as accurate and cost-effective. It must also have good inter-rater and intra-rater reliability. The ability to use this tool remotely would be of further benefit, especially in resource-constrained environments [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eA simple functional outcome test to assess mobility and stability of lower limb joints involves assessing a patient\u0026rsquo;s ability to squat [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. A squat involves lowering the hips from a standing position while bending the knee and ankle joints and returning to a standing position [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. This action is one of the most basic functional movements that is required to perform activities of daily living and religious practices. The Squat and Smile test (SST) was developed as a clinical measure of weight bearing and range of motion (ROM) in LMICs and has been shown to be a possible surrogate for confirming fracture union in lower limb fractures, without the need for radiological imaging [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe SST involves assessing a patient performing a deep squat, with as little support as possible, and observing their facial expression. The rationale is: that if a patient can hold themselves in the squat position and smile, it shows that they have returned to full function. In addition, deep knee bend shows restored ROM. The squat position mechanically stresses the fracture site, testing that bone fragments have healed. It is suggested that the patient\u0026rsquo;s smile indicates that they are pain-free [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. However, a key limitation of the test is that the facial expression component has been shown to correlate poorly with actual fracture union, likely due to its subjective nature [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn this study, we used a modified SST hereafter referred to as the MSST, in which the 'smile' component was adapted to increase objectivity. The primary aim was to evaluate the correlation between the MSST and radiographic fracture union following intramedullary nailing of lower limb long bone fractures. Secondary aims included comparison of individual MSST component scores with fracture union, as well as with the Radiographic Union Score for Tibial fractures (RUST), the EuroQol-5 Dimension (EQ-5D) health-related quality of life score, and the Disability Rating Index (DRI).\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStudy design\u003c/h2\u003e\u003cp\u003eWe performed a retrospective review of data from the HIV in Orthopaedic Skeletal Trauma (HOST) study database, a multi-centre prospective observational study (NCT03131947) involving patients aged\u0026thinsp;\u0026gt;\u0026thinsp;18 years with fresh (within two weeks of injury), closed and open tibia and femur fractures who underwent intramedullary (IM) nailing for fracture fixation [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Data collection for the HOST study took place between September 2017 and December 2018.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eStudy sample\u003c/h3\u003e\n\u003cp\u003eWe included data from patients in the HOST study who had their MSST recorded and videoed during follow-up appointments following IM nailing for femur and/or tibia shaft fractures. Patients without available video footage of the MSST were excluded. Additionally, patients who had undergone contralateral or ipsilateral lower limb IM nailing were excluded to eliminate potential confounding factors affecting functional assessment. Informed consent was obtained from all participants for both study participation and video recording.\u003c/p\u003e\n\u003ch3\u003eData collection\u003c/h3\u003e\n\u003cp\u003eData collected from the HOST study database included patient demographic information, MSST overall test scores, sub scores, fracture union as assessed by the RUST, EQ-5D, and DRI scores. Additionally, we retrieved video footage of patients at their routine follow-up assessments as part of the HOST study. Clinical assessment, x-rays, EQ-5D, DRI, MSST and RUST scores were all recorded at 6 weeks, 3 months, 6 months and 12 months post operatively. If a participant was confirmed united prior to 12 months follow up, the scores at union confirmation was used as the final score.\u003c/p\u003e\n\u003ch3\u003eMSST test\u003c/h3\u003e\n\u003cp\u003eAll patients include had their MSST videoed by the study team. We assessed the \u0026lsquo;smile\u0026rsquo; component of the test by asking patients to point to a picture of a facial expression that best depicts their pain level after performing a squat and by observing dynamic video footage, instead of assessing static photographs, as performed in previous studies. (\u003cb\u003eFig. I\u003c/b\u003e).\u003c/p\u003e\u003cp\u003eThe MSST test video footage for each patient was viewed by two investigators. One was an orthopaedic trainee, and one was a non-specialist. Investigators graded the squat in the following three main domains (Table I): overall squat (0\u0026thinsp;=\u0026thinsp;unable to squat at all, 1\u0026thinsp;=\u0026thinsp;less than 45 degrees flexion at hip, 2 hips above level of the knees, 3\u0026thinsp;=\u0026thinsp;hips at level of the knees or below); the need for support (0\u0026thinsp;=\u0026thinsp;unable to squat unassisted, 1\u0026thinsp;=\u0026thinsp;requires support with two hands, 2\u0026thinsp;=\u0026thinsp;requires support with one hand, 3\u0026thinsp;=\u0026thinsp;no support needed); and smile (1\u0026thinsp;=\u0026thinsp;sad/frown, 2\u0026thinsp;=\u0026thinsp;no smile, 3\u0026thinsp;=\u0026thinsp;smile). The \u0026ldquo;squat\u0026rdquo; component of the score was determined to be either \u0026ldquo;Able to squat\u0026rdquo; (scores of 2 and 3 ) or \u0026ldquo;Unable to Squat\u0026rdquo;(scores of 0 and 1).\u003c/p\u003e\u003cp\u003e\u003cb\u003eTable I.\u003c/b\u003e (Blinded) Squat and Smile Scoring\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSST Domain\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eScore\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eExplanation\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003eOverall squat\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eUnable to squat at all\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLess than 45 degrees of flexion at the hip\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eHips above the level of the knees\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eHips at the level of the knees or below\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003eThe need for support\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eunable to squat unassisted\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRequires support with two hands\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRequires support with one hand\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo support needed\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eSmile\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSad/frown\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo smile\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSmile\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\n\u003ch3\u003eFracture union assessments\u003c/h3\u003e\n\u003cp\u003eBone healing was assessed using the validated radio- logical union scoring system for tibia (RUST). Delayed bone union was defined as impaired bone healing at 6 months on RUST score. Non-union was defined as either impaired bone healing at 9 months on RUST score or the need for further surgery to achieve union (RUST score ,9) before 9 months (decision made by 2 orthopedic surgeons) [\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e Two reviewers (both orthopedic surgeons), blinded to MSST score, independently assessed radiological fracture union on radiographs. In case of discrepancies in RUST scoring between the reviewers, a third reviewer (orthopedic surgeon) independently undertook a review of the radiograph to determine the final outcome.\u003c/p\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eDescriptive statistics were used to summarize participants\u0026rsquo; demographic and clinical characteristics. To evaluate the inter-rater reliability of the MSST, the absolute agreement intra-class correlation coefficient (ICC) and 95% confidence interval (CI) were calculated for the three SST domains (squat, support and smile). The ICC measures score reliability by comparing the variability of different scores assigned to the same participant, with the total variation across all scores and all participants. ICC values\u0026thinsp;\u0026lt;\u0026thinsp;0.50 were categorized as \u0026ldquo;poor agreement\u0026rdquo;; 0.50\u0026thinsp;\u0026le;\u0026thinsp;ICC\u0026thinsp;\u0026lt;\u0026thinsp;0.75 as \u0026ldquo;moderate agreement\u0026rdquo;; 0.75\u0026thinsp;\u0026le;\u0026thinsp;ICC\u0026thinsp;\u0026lt;\u0026thinsp;0.90 as \u0026ldquo;good agreement\u0026rdquo; and ICC\u0026thinsp;\u0026ge;\u0026thinsp;0.90 as \u0026ldquo;excellent agreement\u0026rdquo; [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Fisher\u0026rsquo;s exact test was used to determine the association between fracture union (yes/no), open and closed fractures, and mechanism of injury (MOI).\u003c/p\u003e\u003cp\u003eThe Kendall rank correlation coefficient was used to determine the association between components of the MSST and age, EQ-5D, DRI and RUST scores. The difference in MSST total and sub-domain scores between the union and non-union subgroups was evaluated using the Mann-Whitney U test. All analyses were performed by an independent statistician using IBM SPSS Statistics (Version 27) and the level of significance was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eBetween September 2017 and December 2018, 638 patients underwent IM nailing of the femur and the tibia at the two study sites and were screened for eligibility. 442 IM nails in 400 patients were included in the HOST study. Of these patients, 220 were excluded because a video of MSST was not recorded. Final data analysis was performed on 180 participants (\u003cb\u003eFig. II\u003c/b\u003e).\u003c/p\u003e\u003cp\u003eThe demographic and clinical characteristics of the 180 patients are summarized in \u003cb\u003eTable II\u003c/b\u003e.\u003c/p\u003e\u003cp\u003e\u003cb\u003eTable II.\u003c/b\u003e Demographic and clinical characteristics of the 180 study participants presenting with lower limb fractures.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabb\" border=\"1\"\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eValue\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex, n (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e144 (80)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e36 (20)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean age, years (SD)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.5 (10.6)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMOI, n (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePVA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e74 (41)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMVA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e43 (24)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGSW\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e31 (18)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHigh energy fall\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11 (6)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLow energy fall\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9 (5)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAssault\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (3)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCrush (heavy machinery)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (2)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBlunt force trauma\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3(2)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOther\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (0)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eFracture type, n (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eClosed\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e111 (62)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOpen\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e69 (38)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLocation of fracture and treatment nailing type, n(%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eFemur\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e81 (45)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eRight\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003e51 (63)\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAFN (antegrade)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e39 (76)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRFN (retrograde)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12 (24)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eLeft\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003e30 (37)\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAFN (antegrade)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e25 (83)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRFN (retrograde)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (17)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTibia\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e99 (55)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eRight\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003e50 (51)\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSPN (suprapatellar)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e44 (88)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIPN (infrapatellar)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6 (12)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eLeft\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003e49 (49)\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSPN (suprapatellar)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e47 (96)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIPN (infrapatellar)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (4)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eUnion, n (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e143 (79)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e37 (21)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean EQ-5D index, (SD)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e89.69 (12)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean DRI score, (SD)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e203.5 (159)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eDefinitions\u003c/strong\u003e\u003cp\u003e\u003cem\u003eDRI, Disability Rating Index; MOI, Mechanism of Injury; GSW, Gunshot Wound; RUST, Radiological Union Score; SD, standard deviation. AFN, Antegrade Femoral Nail; IPN, Infrapatellar Nail; RFN, Retrograde Femur Nail; SPN, Suprapatellar Nail.\u003c/em\u003e\u003c/p\u003e\u003c/p\u003e\u003cp\u003eInter-rater reliability was excellent for the two components of the MSST scored by reviewers (Squat and Support) (\u003cb\u003eTable III\u003c/b\u003e).\u003c/p\u003e\u003cp\u003e\u003cb\u003eTable III.\u003c/b\u003e Inter-rater reliability of MSST\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabc\" border=\"1\"\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eMSST components\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eMean scores\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eICC (95% CI)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eObserver 1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eObserver 2\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSquat\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2.2 (0.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.2 (0.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.971 (0.96\u0026ndash;0.98)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2.7 (0.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.6 (0.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e7.2 (1.8)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e7.2 (1.9)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.99 (0.97\u0026ndash;0.99)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe median MSST score for fractures that were united and non-united fractures were 8 and 7 respectively. The difference was not statistically significant (p\u0026thinsp;=\u0026thinsp;0.113)). There were no significant differences in MSST sub-scores between participants with or without fracture union (summarised in \u003cb\u003eTable IV\u003c/b\u003e).\u003c/p\u003e\u003cp\u003e\u003cb\u003eTable IV.\u003c/b\u003e Comparing MSST scores between patients with and without fracture union.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabd\" border=\"1\"\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMSST Domains\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eUnion\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;143\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNon-union\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;37\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMann Whitney U test (z)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eCohen Effect size\u003c/p\u003e\u003cp\u003e(r)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSquat\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (2\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (1\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.235\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-1.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmile\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (2\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (2\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.107\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-1.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (3\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (3\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.771\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e8 (6\u0026ndash;9)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e7 (6\u0026ndash;8.5)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.113\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e-1.59\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e0.12\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eSensitivity and specificity was 81% and 35% respectively, while the positive and negative predicative values were 83% and 33% respectively (\u003cb\u003eTable V\u003c/b\u003e).\u003c/p\u003e\u003cp\u003e\u003cb\u003eTable V.\u003c/b\u003e Comparing ability to squat with union/union\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabe\" border=\"1\"\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAble to Squat (Score of 2\u0026ndash;3)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eUnable to Squat (Score 0\u0026ndash;1)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUnion\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e116 (81%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e27 (19%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e143\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNon Union\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e24 (65%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13 (35%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e37\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e140\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e40\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e180\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\n\u003ch3\u003eSensitivity 116/143 x100, Specificity 13/24 x100, PPV 116/140 x100, NPPV 13/40 x100\u003c/h3\u003e\n\u003cp\u003eEQ-5D had a statistically significant correlation with the total MSST score (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), the squat domain (p\u0026thinsp;\u0026lt;\u0026thinsp;0.01) and the smile domain (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). EQ-5D had no correlation with the support domain.\u003c/p\u003e\u003cp\u003eDRI had a statistically significant inverse correlation with the total MSST score (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), squat domain (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and smile domain (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). DRI had no correlation with the support domain.\u003c/p\u003e\u003cp\u003eAge had an inverse correlation with all three components of the MSST. All these associations were statistically significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\u003cp\u003eRUST score had no correlation to the total MSST score, squat domain and support domain\u003c/p\u003e\u003cp\u003eThe association between RUST and the smile component was significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) (\u003cb\u003eTable VI\u003c/b\u003e).\u003c/p\u003e\u003cp\u003e\u003cb\u003eTable VI.\u003c/b\u003e Kendall\u0026rsquo;s tau correlates with the MSST.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabf\" border=\"1\"\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e\u003cp\u003e(Blinded) Squat \u0026amp; Smile Test\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSquat\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSmile\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eTotal\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eEQ-5D score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.16**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.13*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.10*\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDRI score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.30***\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e-0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-0.27***\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e-0.26***\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.25***\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e-0.16*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-0.14*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e-0.25***\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRUST score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.21**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.12\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003e*p\u0026thinsp;\u0026lt;\u0026thinsp;0.05. **p\u0026thinsp;\u0026lt;\u0026thinsp;0.01. *** p\u0026thinsp;\u0026lt;\u0026thinsp;0.001.\u003c/em\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study aimed to determine the correlation between the (blinded) modified Squat and Smile Test (MSST) and fracture union of lower limb long bone fractures, post intramedullary nailing. We modified the smile domain of the MSST, as it was subjectively assessed and prone to physician bias. We attempted to make the smile component more objective, and we hypothesised that the modified score may correlate better with fracture healing. In our study we found no correlation between the MSST and fracture union.\u003c/p\u003e\u003cp\u003eThere are only three studies looking at the relationship between fracture union and the squat and smile, most of them from the SIGN (Surgical Implant Generation Network) Fracture Care database [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eCurrently, the combination of clinical history assessment with comprehensive examination, and supplementation with radiological imaging, is used to assess fracture healing. Eliezer \u003cem\u003eet al., (\u003c/em\u003e2017) was the first to assess the SST and its correlation with fracture union and found no correlation between the two [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. In 2019, Wu \u003cem\u003eet al.\u003c/em\u003e, defined the domains of the squat and smile test and found that the squat and support domain correlated with the need for reoperation. The most common reasons for reoperation in their study were infection (15/272) and non-union (3/272). Sciuto \u003cem\u003eet al.\u003c/em\u003e, found the squat and smile test correlated with union, but not with the smile domain [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. However, their cohort included paediatric patients and used a different scoring system for fracture union (REBORNE). They also used a different scoring system for the squat and smile (GAS) and not the one originally proposed.\u003c/p\u003e\u003cp\u003eIn our study, quality of health measures in the form of EQ-5D and DRI had a significant correlation with total MSST score, squat domain and smile domain. The support domain had no correlation.\u003c/p\u003e\u003cp\u003eThe smile domain of the MSST correlated with quality-of-life measures, a finding which highlights the previous subjectivity of this component and the need for patient-driven assessment tools and outcome measures. This was expected as both elements take the patient's views and scores of their overall recovery status into account.\u003c/p\u003e\u003cp\u003eThis retrospective review has several limitations. We used data from an existing dataset that determined the study population. A power calculation was not performed for analysis and the findings should therefore be interpreted with caution. Despite no standardisation of how videos were taken, our study showed good reliability of the MSST.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eWe found no correlation between fracture union of lower limb fractures post intramedullary nailing and the MSST, as well as its sub-scores. However, we observed a strong correlation between quality-of-life measures and the MSST, particularly in the squat and smile domains. Notably, the association between the RUST score and the smile component was significant, suggesting that if a patient can smile during the test, it may reflect a level of recovery comparable to radiographic healing. These findings highlight the potential role of the MSST in assessing functional recovery and patient-reported outcomes, rather than as a surrogate for fracture union. Further research is warranted to refine the MSST and to validate its utility in larger, prospective cohorts.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003ch2\u003eEthical Statement (Human Ethics and Consent to Participate)\u003c/h2\u003e\u003cp\u003e Ethical (REF: HREC 590/2016 (blinded) and N17/05/052 (blinded) and hospital institutional approval (blinded) for the was obtained and patient confidentiality was appropriately maintained. Informed consent was obtained from all individual participants included in the study.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e\u003cp\u003eThe HOST study was funded by the Wellcome Trust Research and Training PhD Fellowship and support from AOUK Foundation. This research was supported by the NIHR (NIHR155559) using UK international development funding from the UK Government to support global health research. This study has been delivered through the National Institute for Health and Care Research (NIHR) Oxford Biomedical Research Centre (BRC). The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR or the UK government. This research was also supported by the Medical Research Council (Grant number: MR/Y00955X/1) and the NIHR Oxford Biomedical Research Centre.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by DA. The first draft of the manuscript was written by DA and SMG and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors thank all those who contributed to this research from Groote Schuur and Tygerberg Hospitals, Cape Town, South Africa. Furthermore, the authors would like to thank the significant contribution to this research by Nomsa Yekiso and Nosipho Jennifer Mncwabe.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eData cannot be shared openly but are available on request from authors.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSingaram S, Naidoo M. The physical, psychological and social impact of long bone fractures on adults: A review. Afr J Prim Health Care Fam Med [Internet]. 2019 [cited 2023 Jun 20];11(1). Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/31170796/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/31170796/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSpiegel DA, Gosselin RA, Coughlin RR, Joshipura M, Browner BD, Dormans JP. The burden of musculoskeletal injury in low and middle-income countries: challenges and opportunities. J Bone Joint Surg Am [Internet]. 2008 [cited 2023 Jun 20];90(4):915\u0026ndash;23. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/18381331/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/18381331/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMorshed S. Current Options for Determining Fracture Union. Adv Med [Internet]. 2014 [cited 2023 Jun 20];2014:1\u0026ndash;12. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/26556422/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/26556422/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKauta NJ, Groenewald J, Arnolds D, Blankson B, Omar A, Naidu P, et al. WhatsApp Mobile Health Platform to Support Fracture Management by Non-Specialists in South Africa. J Am Coll Surg [Internet]. 2020 Jan 1 [cited 2023 Jun 20];230(1):37\u0026ndash;42. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/31672673/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/31672673/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCook G, Burton L, Hoogenboom B. Pre-participation screening: the use of fundamental movements as an assessment of function - part 1. N Am J Sports Phys Ther [Internet]. 2006 May [cited 2023 Dec 1];1(2):62\u0026ndash;72. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.ncbi.nlm.nih.gov/pubmed/21522216\u003c/span\u003e\u003cspan address=\"http://www.ncbi.nlm.nih.gov/pubmed/21522216\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLubans DR, Morgan PJ, Cliff DP, Barnett LM, Okely AD. Fundamental movement skills in children and adolescents: review of associated health benefits. Sports Med [Internet]. 2010 [cited 2023 Jun 20];40(12):1019\u0026ndash;35. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/21058749/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/21058749/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWu HH, Liu M, Challa ST, Morshed S, Eliezer EN, Haonga BT, et al. Development of Squat-and-Smile Test as Proxy for Femoral Shaft Fracture-Healing in Patients in Dar es Salaam, Tanzania. J Bone Joint Surg Am [Internet]. 2019 Feb 20 [cited 2023 Jun 20];101(4):353\u0026ndash;9. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/30801374/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/30801374/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVetter TR, Heiner EJ. Discordance between patient self-reported visual analog scale pain scores and observed pain-related behavior in older children after surgery. J Clin Anesth [Internet]. 1996 [cited 2023 Aug 29];8(5):371\u0026ndash;5. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/8832447/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/8832447/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGraham SM, Maqungo S, Laubscher M, Ferreira N, Held M, Harrison WJ, et al. Fracture Healing in Patients With HIV in South Africa: A Prospective Cohort Study. J Acquir Immune Defic Syndr [Internet]. 2021 Aug 15 [cited 2023 Jun 20];87(5):1214\u0026ndash;20. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/33990496/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/33990496/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003e\u0026Ccedil;eki\u0026ccedil; E, Alici E, Yeşil M. Reliability of the radiographic union score for tibial fractures. Acta Orthop Traumatol Turc [Internet]. 2014 [cited 2023 Aug 29];48(5):533\u0026ndash;40. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/25429579/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/25429579/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePanchoo P, Laubscher M, Held \u0026middot; Michael, Maqungo S, Ferreira N, Simpson H, et al. Radiographic union score for tibia (RUST) scoring system in adult diaphyseal femoral fractures treated with intramedullary nailing: an assessment of interobserver and intraobserver reliability. European Journal of Orthopaedic Surgery \u0026amp; Traumatology [Internet]. 2022;32(3):1555\u0026ndash;9. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00590-021-03134-6\u003c/span\u003e\u003cspan address=\"10.1007/s00590-021-03134-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLitrenta J, Tornetta P, Mehta S, Jones C, O\u0026rsquo;Toole R V., Bhandari M, et al. Determination of Radiographic Healing: An Assessment of Consistency Using RUST and Modified RUST in Metadiaphyseal Fractures. J Orthop Trauma [Internet]. 2015 Nov 1 [cited 2023 Jun 20];29(11):516\u0026ndash;20. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/26165265/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/26165265/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKoo TK, Li MY. A Guideline of Selecting and Reporting Intraclass Correlation Coefficients for Reliability Research. J Chiropr Med [Internet]. 2016 Jun 1 [cited 2023 Nov 13];15(2):155\u0026ndash;63. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/27330520/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/27330520/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSciuto D, Marzorati M, Shearer DW, Lanfranconi F. Functional assessment of long bone fracture healing in Samburu County Referral Hospital (Kenya): the squat and smile challenge. OTA Int [Internet]. 2021 Dec [cited 2023 Dec 14];4(4):e148. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.ncbi.nlm.nih.gov/pubmed/34765899\u003c/span\u003e\u003cspan address=\"http://www.ncbi.nlm.nih.gov/pubmed/34765899\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlves KM, Lerner A, Silva GS, Katz JN. Surgical Implant Generation Network Implant Follow-up: Assessment of Squat and Smile and Fracture Healing. J Orthop Trauma [Internet]. 2020 Apr 1 [cited 2023 Jun 20];34(4):174\u0026ndash;9. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/31652187/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/31652187/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMaharjan R, Pokharel B, Shah Kalawar RP, Rijal R, Baral D. Squat and smile assessment in predicting healing of lower limb fractures fixed with a SIGN nail. J Clin Orthop Trauma [Internet]. 2021 Aug 1 [cited 2023 Jun 20];19:34\u0026ndash;41. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/34046298/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/34046298/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEliezer EN, Haonga BT, Morshed S, Shearer DW. Predictors of Reoperation for Adult Femoral Shaft Fractures Managed Operatively in a Sub-Saharan Country. J Bone Joint Surg Am [Internet]. 2017 [cited 2023 Jun 20];99(5):388\u0026ndash;95. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/28244909/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/28244909/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-orthopaedic-surgery-and-traumatology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejos","sideBox":"Learn more about [European Journal of Orthopaedic Surgery \u0026 Traumatology](http://link.springer.com/journal/590)","snPcode":"590","submissionUrl":"https://submission.springernature.com/new-submission/590/3","title":"European Journal of Orthopaedic Surgery \u0026 Traumatology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"fracture union, intramedullary nailing, lower limb, patient-reported outcomes, outcome","lastPublishedDoi":"10.21203/rs.3.rs-7373072/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7373072/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e\u003cp\u003eAssessing fracture union remains a significant challenge in low-resource settings, such as those across Sub-Saharan Africa. The original Squat and Smile Test was developed as a potential surrogate measure for lower limb fracture union, aiming to reduce reliance on follow-up radiographs in environments with limited access to imaging. We evaluated the correlation between the (blinded) Modified Squat and Smile Test (MSST) and fracture union following intramedullary nailing of lower limb long bone fractures.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eWe performed a retrospective review of prospectively collected data from the HIV in Orthopaedic Skeletal Trauma (HOST) study.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eA total of 180 patients with recorded MSST data were included in the analysis. There was no significant correlation between the MSST total score, or its individual domains (squat, support, and smile), and radiological evidence of fracture union. However, health-related quality of life measures (EQ-5D and Disability Rating Index (DRI)) showed a significant positive correlation with the total MSST score, as well as with the squat and smile domains (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). No significant correlation was found between the support domain and these measures.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eThe MSST and its individual domains did not correlate with radiological fracture union following intramedullary nailing of lower limb fractures. However, the test showed significant positive associations with patient-reported outcome measures, suggesting potential utility in assessing functional recovery. Further prospective research is needed to validate the MSST and to explore its role in both clinical assessment and follow-up care in resource-limited settings.\u003c/p\u003e","manuscriptTitle":"The Modified Squat and Smile Test: Correlation with Fracture Union in Long Bone Fractures of the Lower Limb","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-01 09:23:25","doi":"10.21203/rs.3.rs-7373072/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-01T21:27:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-30T17:52:42+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"219767735697887996607171242618514212335","date":"2025-08-27T09:52:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"271332664886068615050627834458347649275","date":"2025-08-23T20:34:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"45898371783562913751018322416365647651","date":"2025-08-23T12:54:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"17290301102551786001938150949348390773","date":"2025-08-22T07:39:23+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-21T11:39:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"240897073789619718563647650905840250316","date":"2025-08-21T11:34:24+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-20T01:56:55+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-14T13:13:56+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-14T13:13:18+00:00","index":"","fulltext":""},{"type":"submitted","content":"European Journal of Orthopaedic Surgery \u0026 Traumatology","date":"2025-08-14T10:49:26+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-orthopaedic-surgery-and-traumatology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejos","sideBox":"Learn more about [European Journal of Orthopaedic Surgery \u0026 Traumatology](http://link.springer.com/journal/590)","snPcode":"590","submissionUrl":"https://submission.springernature.com/new-submission/590/3","title":"European Journal of Orthopaedic Surgery \u0026 Traumatology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"ea830b49-76e0-4278-b507-3c9e470ef5de","owner":[],"postedDate":"September 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-24T16:04:53+00:00","versionOfRecord":{"articleIdentity":"rs-7373072","link":"https://doi.org/10.1007/s00590-025-04532-w","journal":{"identity":"european-journal-of-orthopaedic-surgery-and-traumatology","isVorOnly":false,"title":"European Journal of Orthopaedic Surgery \u0026 Traumatology"},"publishedOn":"2025-11-19 15:59:03","publishedOnDateReadable":"November 19th, 2025"},"versionCreatedAt":"2025-09-01 09:23:25","video":"","vorDoi":"10.1007/s00590-025-04532-w","vorDoiUrl":"https://doi.org/10.1007/s00590-025-04532-w","workflowStages":[]},"version":"v1","identity":"rs-7373072","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7373072","identity":"rs-7373072","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}