Introduction: The hip-spine relationship may influence hip pathomechanics. Cam morphology is associated with pain and arthritis, but not all individuals with such morphology are symptomatic. Aims: This study aimed to (1) Compare spinopelvic characteristics between symptomatic patients with CAM-FAI and a matched cohort of asymptomatic volunteers; (2) assess whether spinopelvic characteristics change following femoral osteochondroplasty (FOCP), and (3) test whether spinopelvic characteristics are associated with patient-reported outcome. Methods: This is a prospective, case-control, study at a tertiary referral hospital. From a cohort of 112 patients treated with hip arthroscopy and 44 asymptomatic volunteers (Oxford Hip Score≥45) without osteoarthritis (Tonnis≤1), 50 patients (25 each group) were matched for age (mean: 39±8 years-old; p=0.5), acetabular- (LCEA: 30±6°; p=0.6; AI 4±5°; p=0.7; AWI 0.48±0.13; p=0.2; PWI: 0.91±0.43; p=0.1) and CAM- (alpha-angle: 56±9°; p=0.9) morphology. All underwent standing and deep-seated spinopelvic radiographs pre-operatively and 1-year post-operatively, to measure lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and pelvic-femoral angle (PFA). Difference between standing and flexed-seated measurements allowed to uncouple lumbar- (∆LL), pelvic- (∆PT) and hip- (∆PFA) mobility. The Hip User index quantifies the relative contribution of the hip to overall sagittal movement and was calculated as [∆PFA/(∆PFA+∆LL)]*100. Outcome was assessed using the international Hip Outcome Tool (iHOT). Results: Pre-operatively, patients had less standing PT compared to controls (11±5° vs. 15±8°; p=0.009) and a lower PFA (190±6° vs. 194±6°; p=0.04). There were no other differences between groups. Post-operatively, patients continued to have lower standing PT (12±7° vs. 15±8°; p=0.02) but had similar similar PFA to controls (194±9° vs. 194±6°; p=0.9). Hip flexion improved by 4±12° (p=0.015), allowing patients to have greater hip flexion than controls (∆PFA 110±16° vs. 101±16°; p=0.013). Hip user index increased following hip arthroscopy (69±7% vs. 63%; p=0.002). In a multi-variate model, pre-operative iHOT was associated with alpha angle (p<0.001), ∆LL (p<0.001), ∆PT (p<0.001) and ∆PFA (p=0.02) (R2 0.9). Standing PFA was best predictor of post-operative iHOT (p=0.001) (R2 0.7). Change in hip mobility moderately correlated with ∆iHOT (rho 0.59). Conclusion: Decreased pelvic tilt is associated with less acetabular anteversion, which reduces impingement-free flexion arc, predisposing to FAI symptoms. iHOT was associated with spinopevic characteristics; the stiffer the segments, the worse the function. Post-surgery, PFA increased (hip more extended when standing) and flexion improved, both of which were associated with patient-reported outcome.

BACKGROUND:Long-term outcomes of femoroacetabular impingement (FAI) surgery, particularly survivorship, are critical to guide treatment decision-making and patient counseling, yet only a limited number of studies have reported mid- to long-term survivorship. The purpose of this study was to report survivorship rates at a mean 10-year follow-up in a large, multicenter FAI surgery cohort and to identify clinical predictors of survivorship. METHODS:A prospective, multicenter cohort study assessed patients treated for FAI with hip arthroscopy or surgical dislocation from 2008 to 2012. At a minimum of 8 years, 362 hips (80.1%) had follow-up that permitted assessment of total hip arthroplasty (THA)-free survivorship. A Cox proportional-hazards model was developed to identify risk factors for THA. RESULTS:tThe cohort included 362 hips with a mean patient age of 32.1 years; 53% were in females, and 95.6% were in Caucasian patients. The THA-free survivorship of the cohort was 90.6% at a mean of 10.4 ± 1.6 years postoperatively. Risk factors for THA were older age at surgery (p = 0.01), male sex (p = 0.02), body mass index of ≥30 kg/m 2 (p = 0.009), and femoral head chondromalacia (p < 0.001). CONCLUSIONS:This study demonstrates that FAI surgery yielded durable 10-year THA-free survivorship of 90.6%. Older age at surgery, obesity, male sex, and femoral head chondromalacia were key predictors of conversion to THA. LEVEL OF EVIDENCE:Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:An accurate measurement of femoral version is essential for diagnosing version abnormalities, determining the need for a surgical intervention, and establishing the extent of correction required. However, in the literature, numerous measurement techniques have been described. PURPOSE:To (1) evaluate the differences among 4 different 2- and 3-dimensional (2D and 3D, respectively) techniques for measuring femoral version, (2) assess the effect of femoral version on differences between measurement techniques, and (3) examine the accuracy of an automated method in determining femoral version using commonly employed techniques. STUDY DESIGN:Cohort study; Level of evidence, 3. METHODS:A total of 100 patients who underwent hip preservation surgery at a single academic center were analyzed (measured and segmented). Pelvic computed tomography was used to measure femoral version using 4 established methods: 2 were 2D axial techniques (Murphy and Reikeras), and 2 were 3D reconstructions (Sugano and Lee). Overall, 4 assessors performed the axial measurements. Measurements were performed relative to the posterior condylar axis (PCA) and transepicondylar axis (TEA). Discrepancies in femoral version between different techniques and interobserver correlations were determined. Linear regression equations to convert femoral version values between methods were established. Using these equations, we calculated the range for each method to be 10° to 25° as per the Murphy method, described as "normative" in the literature. RESULTS:All 2D measurements demonstrated excellent interobserver reliability (interclass correlation coefficients = 0.93-0.97). The mean femoral version according to the 4 methods varied from 3.4°± 9.6° (Lee; lowest) to 23.2°± 11.2° (Murphy; highest). Distally, the TEA exhibited an external rotation of 5.2°± 1.6° relative to the PCA. Linear regression equations showed a strong correlation (R2 > 0.8) for converting femoral version values between methods. The normative range, derived from these equations, varied from 10° to 25° (Murphy) to -7° to 5° (Lee). Excellent correlations were identified between the manual 2D and automatic 3D methods for both distal (TEA: ρ = 0.942, P < .001; PCA: ρ = 0.984, P < .001) and proximal (Reikeras: ρ = 0.924, P < .001; Murphy: ρ = 0.965, P < .001) femoral measurements. CONCLUSION:Femoral version measurements varied significantly between methods, with more proximal reference axes yielding lower values. Despite high reproducibility, the methods differed in mean values, emphasizing the importance of method-specific normal ranges. While 2D methods are common, 3D imaging, supported by quick and user-friendly software, serves as a more detailed and practical assessment.

Background:Debate exists on which functional position (supine or standing) should form the basis of radiographic assessment of the native acetabulum. Pelvic tilt (PT) differs between positions influencing radiographic acetabular assessment. This study aims to (1) quantify PT changes from supine to standing amongst volunteers and patients; (2) assess changes in acetabular parameters between the postures; and (3) determine whether changes in acetabular parameters differ according to acetabular morphotype. Methods:This is a prospective, consecutive, cohort study of 105 asymptomatic volunteers (53% male; mean age 36.5 ± 13.6 years; body mass index [BMI] 25.0 ± 2.0 kg/m2) and 437 patients presenting to a hip preservation clinic without osteoarthritis (Tonnis ≤1) (40% male; mean age 35.7 ± 8.6 years; BMI 25.0 ± 2.0 kg/m2). All underwent standardized supine and standing anteroposterior pelvic radiographs. PT change was quantified using the sacrofemoral-pubic (SFP) angle. Acetabular morphology was evaluated in detail to characterize morphotype according to the Ottawa classification (lateral dysplasia, anterior dysplasia, posterior dysplasia), pincer or "normal." Changes between supine and standing were compared between cohorts and morphotypes. Results:The mean SFP decreased by -3.7° (IC95% 4.0-3.5) from supine to standing. Acetabular measurements demonstrated no differences in change between volunteers and symptomatic patients when transitioning between supine to standing. Measurements of lateral coverage changed minimally between supine (volunteers: 30.7° ± 6.1°; symptomatics: 27.3° ± 8.3°) and standing (volunteers: 30.3° ± 5.7°; symptomatics: 26.1° ± 8.1°), whereas measurements reflecting anteroposterior coverage changed significantly (ΔAWI volunteers: -0.10 ± 0.08 and symptomatics: -0.09 ± 0.07; p < 0.001 and ΔPWI volunteers: 0.09 ± 0.08 and symptomatics: 0.09 ± 0.07; p < 0.001). Patients with anterior dysplasia demonstrated smaller ΔSFP (-1.5° ± 2.5° vs. -3.7° ± 2.9°; p = 0.004) compared with the rest of the cohort. By contrast, posterior dysplasia showed greater ΔSFP (-4.5° ± 2.7° vs. -3.6° ± 2.9°; p = 0.128) than the rest. Conclusions:Groups demonstrated comparable changes in PT and acetabular parameters between positions. The magnitude and direction of change was associated with acetabular morphology uncoupling compensatory mechanisms. Standing radiographs may be preferred to supine, as they account for compensatory mechanisms. Level of Evidence:Level II, diagnostic. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:The mandatory collection of patient-reported outcome measures and the implementation of thresholds for hip and knee replacement surgery represent a growing international trend in value-based health-care policy. Our aim was to investigate whether the Oxford Hip Score (OHS) and Oxford Knee Score (OKS) can be used to accurately predict patient satisfaction, and to estimate thresholds to guide value-based health-care policy. METHODS:All primary total hip replacements (THRs) and total knee replacements (TKRs) for osteoarthritis undertaken at a tertiary academic institution over a 6-year period were identified. Logistic regression models were used to evaluate preoperative and postoperative values for the OHS and OKS, and the change between them, as predictors of patient satisfaction. Optimal thresholds for both the minimal clinically important difference (MCID) and the substantial clinical benefit (SCB) were identified. RESULTS:A total of 1,429 THRs (mean patient age, 66.1 years, standard deviation [SD], 11.1 years; 819 [57.3%] female) and 1,079 TKRs (mean patient age, 68.3 years, SD, 8.4 years; 635 [58.9%] female) were included. For the postoperative OHS, thresholds of 35.5 (95% confidence interval [CI], 29.1 to 41.9) for the MCID and 36.5 (95% CI, 33.0 to 40.0) for the SCB were identified. For the postoperative OKS, thresholds of 30.5 (95% CI, 24.2 to 36.8) for the MCID and 38.5 (95% CI, 36.7 to 40.3) for the SCB were identified. For the change in OHS, thresholds of 19.5 (95% CI, 13.4 to 25.6) for the MCID and 20.5 (95% CI, 16.0 to 25.0) for the SCB were identified. For the change in OKS, thresholds of 13.5 (95% CI, 8.3 to 18.7) for the MCID and 14.5 (95% CI, 11.7 to 17.3) for the SCB were identified. Patients with worse preoperative function had higher thresholds. Preoperative Oxford scores were poor predictors of patient satisfaction. CONCLUSIONS:The thresholds for the postoperative Oxford scores and change scores may guide value-based health-care decision-making using the OHS and OKS. LEVEL OF EVIDENCE:Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Osteoarthritis (OA) represents a multifaceted pathology characterized by intricate signaling across various joint tissues, where the sub-synovial adipose tissue (ssAT) has been suggested to play diverse roles, from serving as a stem cell reservoir, mechanosensing, serving as a neuroendocrine organ, to modulating inflammation. In this study, we aimed to uncouple the cellular and molecular alterations within the human hip ssAT (the pulvinar) linked to OA and aging, elucidating the distinct contributions of disease onset and progression versus normal aging. Our findings show a pronounced increase in mesenchymal stem/progenitor cells (MSPCs) in the osteoarthritic pulvinar, associated with the upregulation of putative MSPC markers (DPP4, and THY1), indicating an adaptive repair response. Concurrently, in OA patients we observed an altered immune landscape featuring reduced innate immune cells and elevated exhausted CD8+ cells, along with upregulation of genes critical for inflammation and fibroblast activation. Our findings reveal a nuanced picture of OA, where increased stem cell numbers and vascularization, combined with specific gene expression patterns differentiate OA from normal aging. This study not only delineates the roles of inflammation, immune regulation, and stem cell activity in the OA pulvinar but also identifies potential therapeutic targets to modulate these pathways, offering novel insights into OA as a complex interplay of degenerative and intrinsic tissue repair.

In PJI revision surgery, prolonged wound drainage (PWD) is a common concern associated with increased periprosthetic joint infection (PJI), yet no clinical guidelines exist, guiding when intervention should occur. This study aimed to quantify the association between PWD and treatment failure following hip PJI surgery, and which factors were associated with those results. A retrospective cohort study of hip PJI patients was conducted from March 2019 to January 2023. Univariate and multivariate logistic regression was performed to identify risk factors associated with PWD and failure of treatment (per modified Delphi criteria) Statistical significance was considered for p<0.05. 164 patients were identified: 98 women (59.8

Introduction: Recent work in total knee arthroplasty (TKA) prosthetic joint infection (PJI) suggests that timing from hospital admission to DAIR (debridement, antibiotic, and implant retention) is a modifiable risk factor influencing treatment outcomes. The study assessed the impact of timing from admission to DAIR on clinical outcomes and treatment success in the total hip arthroplasty (THA) PJI population. Methods: A retrospective review was conducted at a specialized PJI tertiary referral centre. Patients who underwent DAIR for THA PJI between 2008 and 2021 with a minimum 2-year follow-up were included. The primary outcome was reoperation for recalcitrant PJI. Secondary outcomes included 90 d readmission, 90 d and 1-year mortality, and postoperative complications. Multivariate regression analysis identified factors associated with DAIR outcomes. Results: A total of 100 patients satisfied the inclusion criteria. The mean time from admission to DAIR was 46.4 ± 45.1 h, and 52.0 % required reoperation for recalcitrant PJI. Prolonged time from admission to DAIR was associated with increased 90 d mortality (odds ratio or OR: 1.02, CI (confidence interval) 95 %: 1.00-1.03, p = 0.04). Increasing age was associated with greater 1-year mortality (OR: 1.06, CI 95 %: 1.00-1.12, p = 0.049). McPherson host grade C compared to grade A was associated with both greater 1-year mortality (OR: 12.75, CI 95 %: 1.11-146.09, p = 0.04) and postoperative complications (OR: 7.59, CI 95 %: 1.22-47.08, p = 0.03). McPherson extremity grade II versus grade I (OR: 3.28, CI 95 %: 1.21-8.92, p = 0.02) and revision THAs (OR: 0.15, CI 95 %: 0.03-0.72, p = 0.02) were associated with postoperative complications. Lower haemoglobin levels (OR: 1.04, CI 95 %: 1.01-1.07, p = 0.004) were associated with higher reoperation risk. Conclusion: In a DAIR-treated cohort, increased time from admission to surgery was associated with greater 90 d mortality in THA PJI patients. Timely surgical intervention and optimization of modifiable risk factors are essential to improve outcomes.

Background: Long-term outcomes of femoroacetabular impingement (FAI) surgery, particularly survivorship, are critical to guide treatment decision-making and patient counseling, yet only a limited number of studies have reported mid- to long-term survivorship. The purpose of this study was to report survivorship rates at a mean 10-year follow-up in a large, multicenter FAI surgery cohort and to identify clinical predictors of survivorship. Methods: A prospective, multicenter cohort study assessed patients treated for FAI with hip arthroscopy or surgical dislocation from 2008 to 2012. At a minimum of 8 years, 362 hips (80.1%) had follow-up that permitted assessment of total hip arthroplasty (THA)-free survivorship. A Cox proportional-hazards model was developed to identify risk factors for THA. Results: tThe cohort included 362 hips with a mean patient age of 32.1 years; 53% were in females, and 95.6% were in Caucasian patients. The THA-free survivorship of the cohort was 90.6% at a mean of 10.4 ± 1.6 years postoperatively. Risk factors for THA were older age at surgery (p = 0.01), male sex (p = 0.02), body mass index of ≥30 kg/m 2 (p = 0.009), and femoral head chondromalacia (p < 0.001). Conclusions: This study demonstrates that FAI surgery yielded durable 10-year THA-free survivorship of 90.6%. Older age at surgery, obesity, male sex, and femoral head chondromalacia were key predictors of conversion to THA. Level of Evidence: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:Total hip arthroplasty (THA) is a common treatment for displaced femoral neck fractures (FNFs). Dual mobility (DM) THA has been advocated to reduce dislocation risk in high-risk patients, such as those who have FNF. However, comparative studies remain limited. The purpose of our study was to answer the following questions: (1) What is the dislocation incidence between DM-THA and conventional THA (c-THA) in patients who have FNF? (2) What is the revision incidence between DM-THA and c-THA in patients who have FNF? and (3) What are the risk factors for dislocation in patients who have THA for FNF? METHODS:A multicenter retrospective cohort study involving 822 patients who underwent THA for displaced FNF at four public hospitals between 2012 and 2020 was conducted. Propensity matching (2:1) balanced age, sex, American Society of Anesthesiologists score, surgical approach, and surgeon experience to analyze dislocation and revision incidence between DM-THA and c-THA. Kaplan-Meier survival analysis and multivariable logistic regressions were performed. RESULTS:Following propensity matching (209 DM-THA versus 418 c-THA), DM-THA demonstrated lower dislocation incidence up to five years (0.5% [95% confidence interval 0 to 2.5%] versus 4.8% [95% confidence interval 3.0 to 7.2%], P = 0.005). However, there was no difference in the revision for instability (DM THA: 0.5% versus c-THA: 2.0%; P = 0.2) or revision for all causes (DM THA: 3.1% versus c-THA: 3.9%; P = 0.3). CONCLUSIONS:Use of DM-THA reduces dislocation risk in FNF without increasing overall revision incidence, supporting its use in high-risk patients. LEVEL OF EVIDENCE:Prognostic study level III.

Background:One of the most common causes of failure after metal-on-metal hip resurfacing (MoM HR) remains femoral neck fracture and aseptic loosening of the femoral component. The purpose of this study was to compare the survivorship of cemented and cementless femoral fixation metal on metal hip resurfacing. Methods:Five-hundred ninety patients' MoM HR performed through the Hueter-anterior approach with a minimum 5-year (mean age 50 years, body mass index (BMI) 29, 555 men and 35 women) follow-up were reviewed. One hundred and forty-three cementless (mean age 50 years, mean BMI 29, 136 men and 7 women) and 143 cemented MoM HR (mean age 52 years, mean BMI 29, 136 men and 7 women) were matched on age, sex, and BMI. Overall failures, femoral failures, adverse events, and complications were assessed. Acetabular cup inclination, neck-shaft angle (NSA), stem-shaft angles (SSA), Δ NSA-SSA, and neck narrowing were recorded. Results:Survivorship was 91% at a mean follow-up of 8.2 years (range 5-19). There were 14 failures (10% rate) in the cemented group and 12 failures (8% failure rate) in the cementless group (p > 0.05) with men at 92.7% and women at 74.9% (p = 0.019). In the male group, using isolated femoral reasons for revision survivorship was 96.5% for the cemented group and 98% for the cementless group (p > 0.05). Neck narrowing more than 10% was present in 11 patients (8%) in the cemented group and in 3 patients (2%) in the cementless group (p < 0.01). No significant correlation was found between any radiological parameter and the risk of failure. Conclusion:Both cementless and cemented MoM HR are associated with excellent survivorship, especially in men with cementless fixation having a lower incident of neck narrowing.

OBJECTIVE:To describe and compare the factors that impact initial rehabilitation type after hip fracture surgery. DESIGN:Retrospective population-based cohort study. SETTING AND PARTICIPANTS:People aged between 50 and 105 with a hip fracture who had a surgical repair in Ontario, Canada, between January 1, 2015, and December 31, 2021. METHODS:Descriptive statistics and a multinomial logistic regression model were used to identify factors associated with initial rehabilitation type. RESULTS:In this study, 63,401 individuals were included with a mean age of 80 years [standard deviation (SD) 10.9], mostly female (67.3%), with 86.3% living in urban areas at the time of hospitalization and most (72.6%) admitted from the community without home care. A total of 24.5% of individuals did not receive any form of rehabilitation. Rurality of residence decreased the odds of having an initial rehabilitation type in complex continuing care [odds ratio (OR), 0.23; 95% CI, 0.21-0.26], in inpatient rehabilitation (OR, 0.26; 95% CI, 0.24-0.28), or in community rehabilitation (OR, 0.54; 95% CI, 0.50-0.58) compared with no rehabilitation. Dementia decreased the odds of having an initial rehabilitation type in complex continuing care (OR, 0.75; 95% CI, 0.69-0.81), in inpatient rehabilitation (OR, 0.44; 95% CI, 0.41-0.47), or in community rehabilitation (OR, 0.88; 95% CI, 0.82-0.95) compared with receiving no rehabilitation. Previous history of fragility fracture decreased the odds of having an initial rehabilitation type in either complex continuing care (OR, 0.30; 95% CI, 0.27-0.34), in inpatient rehabilitation (OR, 0.27; 95% CI, 0.24-0.29), or in community rehabilitation (OR, 0.33; 95% CI, 0.30-0.37) compared with no rehabilitation. CONCLUSIONS AND IMPLICATIONS:Rurality of residence, dementia, and previous history of fragility fractures reduced the odds of receiving specialized inpatient rehabilitation and increased the odds of receiving no rehabilitation. Future research should focus on achieving more equitable care for individuals living in rural settings, with dementia, or with previous fragility fractures to enhance the quality of care and achieve best outcomes for the overall hip fracture population.

Cam-type femoroacetabular impingement (FAI) is a condition in which excess bone at the femoral head–neck junction can damage the labrum and cartilage tissue. FAI is common, occurring in 22–55% of patients with hip pain [1]. Femoral osteochondroplasty is a common treatment, but low patient satisfaction has been reported [2]. We propose 3D-printed models for surgical planning to ensure a healthy post-operative labral seal. MRI and CT images from a healthy hip joint were segmented, including all soft tissues but the ligamentum teres. The Ottawa Hospital Research Institute ethics board approved secondary use of deidentified images. Material jetting 3D printing was used to create a multi-material hip joint model. Distraction testing was performed following established methods [3] to quantify labral seal efficacy. The model was mounted to a tensile testing machine in a neutral pose and the joint was lubricated with vacuum grease. The model was compressed to form the labral seal and then pulled until the seal was broken; force and displacement were measured. The maximum distraction force and displacement at seal break were averaged over five trials and compared to existing cadaveric studies [4–11]. The maximum distraction force was 116 ± 11 N (mean ± standard deviation) and the displacement at labral seal break was 3.31 ± 0.235 mm. Our 3D-printed model demonstrated similar maximum distraction force and displacement as cadaveric tests, and shows promise as a new tool for surgical planning. Future work includes submerging the joint during testing to better simulate physiological conditions. 1 Best & Martin, Principles of Orthopedic Practice for Primary Care Providers, 2nd ed, 159–72, 2021. 2. Farjo et al, Arthroscopy, 15:132–7, 1999. 3. Lee et al, Am J Sports Med, 43:98–104, 2015. 4. Suppauksorn et al, Arthroscopy, 38:365–73, 2022. 5. Nepple et al, Knee Surg Sports Traumatol Arthrosc, 22:730–6, 2014. 6. Utsunomiya et al, Am J Sports Med, 48:2733–9, 2020. 7. Maldonado et al, Am J Sports Med, 50:2462–8, 2022. 8. Storaci et al, Am J Sports Med, 48:2726–32, 2020. 9. Kaplan et al, Arthroscopy, 40:2575–84, 2024.

Aims:As the number of patients who undergo total joint replacement as an outpatient continues to increase, it is essential that the safety and efficacy of this form of treatment is maintained. The aim of this study was to examine the outcome in a series of very obese patients who underwent total hip arthroplasty (THA) as an outpatient. Methods:A prospective database was used to identify 381 patients who underwent THA as an outpatient. Using case-control matching based on age, sex, and American Society of Anesthesiologists grade, 51 very obese patients with a BMI > 35 kg/m2 were matched to 51 patients with a BMI < 35 kg/m2 who underwent THA as an outpatient. In a subsequent analysis, 47 patients (41 THAs) from the same very obese cohort were matched to 47 very obese patients who underwent THA as an inpatient. For each group, readmission within 90 days, return to the emergency department (ED) within 90 days, adverse events, and reoperations were recorded. Results:The mean BMI of the very obese outpatient group was 40 kg/m2 (35 to 55); their mean age was 61 years (38 to 78). The mean BMI of the outpatients with a BMI < 35 kg/m2 was 27 kg/m2 (17 to 34); their mean age was 61 years (33 to 78). The mean BMI of the very obese inpatient group was 40 kg/m2 (35 to 55); their mean age 62 years (34 to 77). Between the two outpatient groups, the rate of adverse events was significantly higher in the very obese group (15.69% compared with 1.96% (p = 0.015)). The reoperation rate was also significantly higher in the very obese group (five cases compared with none; p = 0.022). The rate of readmission and return to the ED within 90 days did not differ significantly between the groups (p = 0.299 and p = 0.092, respectively). There was no significant difference for all outcomes between the very obese patients who were treated as an outpatient and those who were treated as an inpatient. Conclusion:The very obese group had significantly higher rates of adverse events and reoperations compared with those with a BMI < 35 kg/m2, but there was no difference when they were compared with a matched cohort of very obese patients who were treated as an inpatient. Caution must always be taken to identify the ideal candidates for outpatient surgery. However, BMI should not be used as a sole variable for deciding whether THA should be undertaken as an inpatient.

BackgroundThe use of machine learning (ML) in surgery till date has largely focused on predication of surgical variables, which has not been found to significantly improve operating room efficiencies and surgical success rates (SSR). Due to the long surgery wait times, limited health care resources and an increased population need, innovative ML models are needed. Thus, the Framework for AI-based Surgical Transformation (FAST) was created to make real time recommendations to improve OR efficiency.MethodsThe FAST model was developed and evaluated using a dataset of n=4796 orthopedic cases that utilizes surgery and team specific variables (e.g. specific team composition, OR turnover time, procedure duration), along with regular positive deviance seminars with the stakeholders for adherence and uptake. FAST was created using six ML algorithms, including decision trees and neural networks. The FAST was implemented in orthopedic surgeries at a hospital in Canada's capital (Ottawa).ResultsFAST was found to be feasible and implementable in the hospital orthopedic OR, with good team engagement due to the PD seminars. FAST led to a SSR of 93% over 23 weeks (57 arthroplasty surgery days) compared to 39% at baseline. Key variables impacting SSR included starting the first surgery on time, turnover time, and team composition.ConclusionsFAST is a novel ML framework that can provide real time feedback for improving OR efficiency and SSR. Stakeholder integration is key in its success in uptake and adherence. This unique framework can be implemented in different hospitals and for diverse surgeries, offering a novel and innovative application of ML for improving OR efficiency without additional resources.

Metal-on-metal (MoM) hip resurfacing (HR) has shown excellent results in male patients with adequate head size and suitable morphology. However, due to the long-term risk of adverse tissue reactions, particularly in females as well as limitations in component sizes, ceramic-on-ceramic (CoC) HRA has been introduced as an alternative. This study aims to examine overall survivorship and the effect of gender and component sizes on the five-year survivorship of the ReCerf CoC HRA. An international retrospective analysis was conducted on 604 consecutive patients (330 males, 264 females) with a mean age of 50.1 years (range 20–80 years) who underwent CoC HR from 3 September 2018 to 4 June 2024. All revisions were captured, and no patients were lost to follow-up. Kaplan-Meier analysis was used to determine the survivorship at 5 years. Cox proportional hazards model was used to analyse the influence of gender and implant size on the risk of revision. At a mean follow-up of 3.6 years (range: 2.4–5.7 years), the 5-year survivorship was 98.2% (95% CI 96.7–99.0%). The 5-year survivorship rates were 98.1% for males (95% CI 95.7–99.1%), 98.4% for females (95% CI 95.7–99.4%), 98.4% for femoral head sizes ≤ 48 mm (95% CI 95.9–99.4%), and 98% for head sizes ≥ 48 mm (95% CI 95.6–99.1%). Multivariate analysis indicated that neither sex nor smaller head sizes had a statistically significant impact on revision risk: males had an odds ratio (OR) of 1.2 (95% CI 0.21–6.9, p-value 0.84), and an increase in head diameter by 1 mm was associated with an OR of 1.0 (95% CI 0.81–1.23, p-value 0.99). CoC HRA demonstrates excellent survivorship at 5 years, irrespective of gender or implant size. This compares favourably to previously published outcomes for MoM HR, which typically report lower survivorship in female patients and smaller component sizes. Longer-term follow-up is required to confirm these outcomes.

Background: Long-term outcomes of FAI surgery are critical to understand it’s hip preserving ability, yet few studies have reported mid to long-term survivorship following FAI surgery. The purpose of this study was to report rates of treatment failure after first-generation FAI surgery at an average 10- year follow-up. Methods: A prospective, multicenter cohort study assessed patients treated for FAI with hip arthroscopy or surgical dislocation by seven surgeons at four institutions from 2008 to 2012. Inclusion criteria included primary surgery and diagnosis of isolated cam or combined cam/pincer type FAI. At an average 10-year follow-up, 362/452 eligible hips (80.1%) achieved follow-up. Cox proportional hazards model was used to identify predictors of conversion to total hip arthroplasty (THA). Results: Three hundred and sixty two hips were evaluated at a mean of 10.0 ± 2.3 years follow-up. At time of final follow-up, 34 hips (9.2%) had undergone conversion to THA at a mean of 5.2 ± 3.1 years post-operatively. An additional 18 patients (4.9%) underwent non-arthroplasty revision preservation surgery at a mean of 2.0 ± 1.5 years post-operatively. The Kaplan Meier survivorship rates after 5 and 10 years of surgery were 94.9% and 95.2% for conversion to THA and 91 % and 95.2% for revision hip preservation. Older age (HR:1.06, CI: 1.01-1.10; p=0.009), BMI≥30 (HR:4.14, CI:1.52-11.24, p=0.005), male sex (HR:3.23, CI: 1.18-9.09, p=0.02), and lower baseline mHHS (HR:1.03, CI: 1.01-1.04, p=0.01) were significant predictors of conversion to THA. Conclusion: This study demonstrates that FAI surgery yields durable outcomes with the majority of patients (85.9%) not requiring revision surgery or conversion to total hip arthroplasty at an average 10 years. Age 30 years, male sex, and obesity were significantly associated with the risk of THA conversion.

Aims:We aimed to determine if a home-based hip exercise programme, designed to use strength and flexibility exercises to modify pelvic positioning, is superior to usual care in reducing pain and improving function and quality of life in patients with symptomatic femoroacetabular impingement (FAI). Methods:This was a single-blind parallel-group randomized controlled trial. Eligible participants were aged ≥ 16 years and diagnosed with symptomatic cam FAI. A sample size of 94 was needed to detect a clinically important difference. Participants were randomly allocated to: 1) an eight-week home-based exercise programme focused on posterior pelvic tilt supervised by a physiotherapist every two weeks in addition to usual care; and 2) usual care. The primary outcome measure was function (patient-reported 33-Item International Hip Outcome Tool (iHOT-33)) and secondary outcome measures were quality of life (EuroQol five-dimension five-level questionnaire (EQ-5D-5L)), and pain (visual analogue scale (VAS)) at baseline, nine weeks, and six months. The Mann-Whitney U test was used to test between-group differences in scores using a two-tailed level of significance of p < 0.05. Results:A total of 95 participants were recruited (48 intervention, 47 control), 55 were males (57.9%), the mean age was 32 years (SD 8.5), and both groups were similar at baseline. There were no statistically significant differences in the primary outcome measure between groups at nine weeks and six months for function (nine weeks: p = 0.394, 95% CI -15.5 to 6.5; six months: p = 0.526, 95% CI -8.8 to 13.7). There were no statistically significant differences in the secondary outcome measures between groups: pain (nine weeks: p = 0.153, 95% CI -0.4 to 2.4; six months: p = 0.743, 95% CI -1.1 to 1.7), and quality of life (quality of life VAS nine weeks: p = 0.877, 95% CI -10.0 to 6.0; six months: p = 0.269, 95% CI -15.0 to 5.0; index value nine weeks: p = 0.815, 95% CI -0.067 to 0.052; six months: p = 0.217, 95% CI -0.099 to 0.020). Conclusion:Our results demonstrated no statistical differences in pain, function, and quality of life for participants following an eight-week home-based exercised programme supervised by a physiotherapist compared to usual care.