Citations

Introduction: Manual measurement of leg length (LL) and offset can be tedious. This study developed an automated algorithm for measuring LL and offset from pre- and postoperative AP pelvis radiographs in a large cohort of THA patients. Methods: Using a deep learning model trained on 1100 total AP pelvis radiographs, an algorithm was developed to calculate LL and offset. Algorithm measurements were compared with manual measurements by 4 raters on a sample of 100 pre- and postoperative image pairs. Inter- and intra-rater consistency was calculated using the intraclass correlation coefficient (ICC). The algorithm was applied to calculate the pre- and postoperative LL and offset discrepancies and the change in LL and offset bilaterally in a cohort of 15,951 image pairs. Results: ICC values between the algorithm and human raters ranged from 0.83 to 0.88 for offset measurements and 0.92 to 0.97 for LL measurements. Human raters demonstrated good-to-excellent inter-rater ICC and uniformly excellent intra-rater ICC. Entire database measurements demonstrated shorter LLs for arthritic joints versus the contralateral leg preoperatively and reduced LL discrepancy post-arthroplasty. Conclusions: We present a deep learning algorithm for calculating LL and offset using AP pelvis radiographs. This tool can support population-level studies and may assist operative management.

Abstract Purpose Iliopsoas tendinitis following total hip arthroplasty (THA) has been described to result from acetabular component overhang as well as prominent femoral collars. Yet, a portion of patients experience iliopsoas tendinitis in the setting of well-positioned components. The purpose of this study was to assess anatomic factors predisposing to iliopsoas tendinitis after THA. Methods Patients with THAs performed at three academic institutions who subsequently underwent arthroscopic iliopsoas release were retrospectively reviewed from 2015 to 2025 and propensity matched in a 1:3 fashion to a control group of THAs without subsequent iliopsoas release. Controls were matched by age, surgery date, laterality, sex, surgical approach, and implanted femoral component. Patients with iliopsoas tendinitis and subsequent release (THA-IP) were evaluated for anterior acetabular component overhang and femoral collar overhang, when a collar was present. We also evaluated the absolute and relative profile of the lesser trochanter on anteroposterior radiographs, understanding that when less of the lesser trochanter is visualized, the trochanter is anatomically displaced posterolaterally, resulting in a more arduous route from the inner pelvic origin of the iliopsoas to its insertion on the femur. Results Forty-five patients (mean age: 57±11; 71% female; 19 direct anterior, 10 anterolateral, 16 posterior approach) undergoing THA-IP were analyzed and matched to 135 controls. Both groups demonstrated a median cup size of 54 mm and head size of 36 mm. Average time to iliopsoas release after THA was 4 years. Anterior cup overhang of >2 mm was present in 49% of THA-IP patients, with 18% having collared femoral components, and 9% demonstrating collar overhang of >2 mm. Overall, 19 THA-IP patients had <2 mm of cup and collar overhang and 26 patients had >2 mm of overhang. THA-IP patients with <2 mm of cup and collar overhang had significantly greater relative posterolateralization of the lesser trochanter compared to those with overhang of >2 mm (p=0.010) and to controls (p=0.037). Conclusion Visualizing “Less of the Lesser” on anteroposterior hip radiographs and associated posterolateralization of the lesser trochanter may be an anatomic risk factor for iliopsoas tendinitis following THA, even in the presence of satisfactorily positioned components.

Abstract Introduction Understanding factors that impact outcomes of total hip arthroplasty (THA) can aid clinical decision-making and patient counselling. The purpose of this study was to investigate functional outcomes, complications, and reoperation rates among patients undergoing primary THA after hip arthroscopy (HA-THA) compared to a matched cohort of primary THA patients without prior arthroscopy (THA-only). Methods A retrospective review was performed to identify all patients who underwent primary THA after prior hip arthroscopy from 2009-2022 at a single institution. Patients with a history of revision arthroscopy were excluded. Cases were propensity-matched with primary THA controls in a 1:4 ratio by age at time of THA, sex, body mass index, surgical approach, and year of surgery. At minimum 2-year follow-up, patient-reported outcomes (PROs) including Forgotten Joint Score (FJS), Modified Harris Hip Score (mHHS), Hip Disability and Osteoarthritis Outcome Score Pain (HOOS pain), and Visual Analog Pain Scale (VAS) were analyzed. Results Sixty-three hips in 60 patients (age: 47.3±9.4 years, BMI: 29.8±6.2 kg/m2) were matched to 252 THA-only hips, with patients converting to THA at a mean 3.1 years (range 0.3-10.3) following hip arthroscopy. While both HA-THA and THA patients demonstrated significant (p<0.001) postoperative improvements in PROs, HA-THA patients reported significantly lower postoperative FJS, mHHS, HOOS pain, and VAS pain scores (p<0.001) as compared to THA-only controls. At mean 6.6±3.2 years follow-up, HA-THA patients with preoperative Tönnis grades 2-3 reported significantly increased FJS, mHHS, and HOOS pain compared to those with preoperative Tönnis grades of 0-1 (p≤0.03). Additionally, HA-THA patients with preoperative Tönnis grades 0-1 exhibited worse PROs (p<0.001) as compared to THA-only controls. While there were no differences in complication rates between HA-THA patients and THA-only controls (8% vs. 5%, p=0.49), all-cause reoperation was greater amongst HA-THA patients compared to THA-only (10% vs. 2%, p=0.01). Conclusion While improved compared to preoperatively, patients undergoing THA after prior hip arthroscopy demonstrated inferior outcomes at mid-term follow up as compared to a demographically age-matched cohort without prior arthroscopy. When considering conversion to THA following arthroscopy, clinicians should consider counseling patients regarding improved outcomes in the setting of advanced radiographic osteoarthritis, and potentially increased all-cause reoperation.

As artificial intelligence (AI) advances in healthcare, encompassing robust applications for the diagnosis and prognostication of musculoskeletal diseases, clinicians must increasingly understand the implications of machine learning and deep learning in their practice. This review article explores computer vision algorithms and patient-specific, multimodal prediction models; provides a simple framework to guide discussion on the limitations of AI model development; and introduces the field of generative AI.

Purpose To evaluate the differences in clinical outcomes and complication rates between open and arthroscopic iliopsoas (IP) tenotomy between 1998 and 2023 at our institution. Methods Patients who underwent arthroscopic iliopsoas fractional lengthening (IPFL) or open tenotomy for IP tendinitis following total hip arthroplasty (THA) between 1988 and 2023 were identified. Patients were excluded if they underwent revision IP tendon release, had additional concomitant procedures, or had less than a 24‐month postoperative follow‐up. Patient records were reviewed, and patient‐reported outcomes were collected via electronic survey. Results Fifty‐two patients (36 arthroscopic, 16 open) were followed for an average of 68.7 (24.0‐203.7) months. Overall surgery satisfaction was 7.9 (scale 0‐10) following arthroscopic IPFL and 6.0 following open tenotomy ( P = .178). Eighty‐six percent of patients reported improvement in their anterior groin pain following arthroscopic IPFL, compared to 45% following open tenotomy ( P = .065). In the arthroscopic cohort, 64% reported improved hip flexion strength, compared to 36% in the open cohort ( P = .158). Visual analog scale for pain at rest was lower following arthroscopic IPFL (1.1 ± 2.2 vs 3.3 ± 3.2, P = .0092), while pain with use did not differ between cohorts (3.1 ± 1.3 vs 2.6 ± 1.1, P = .786). There were no differences in postoperative Tegner (3.1 ± 1.3 vs 2.6 ± 1.1, P = .302), modified Harris Hip Score (77.0 ± 19.0 vs 69.2 ± 26.9, P = .073), or Single Assessment Numeric Evaluation (70.9 ± 28.7 vs 66.7 ± 31.8, P = .571) scores between arthroscopic and open cohorts. Revision THA rates did not differ following arthroscopic or open procedures (8.3% vs 25%, P = .104). Conclusions Patients have improved pain at rest following arthroscopic IPFL when compared to open tenotomy for IP tendinitis following THA. Overall complication and reoperation rates were low for both techniques. Level of Evidence Level III, retrospective cohort study.

Abstract Background: Iliopsoas (IP) tendinitis is a recognized complication following total hip arthroplasty (THA) and isolated iliopsoas fractional lengthening (IPFL) has been able to provide symptom relief. IPFL has traditionally been done openly; however, the arthroscopic IPFL has recently been described as an alternative, offering the potential for lower surgical site morbidity and a more favorable post-operative recovery. Purpose: To compare clinical and patient reported outcomes following open and arthroscopic IPFL. We hypothesize that patients undergoing arthroscopic IPFL will have improved pain, function, and satisfaction with lower post-operative complication rates when compared to patients undergoing open IPFL. Methods: Patients with symptomatic IP tendinitis following THA who underwent IPFL from 1988-2023 were reviewed. Inclusion criteria included 2 years follow-up and no concomitant procedures. Patient records were evaluated for surgery type, radiographic anterior acetabular component overhang, reoperations, and need for revision THA. Surveys were used to report overall surgery satisfaction, postoperative subjective hip flexion strength and anterior groin pain improvement, mHHS, SANE score, Tegner activity scale, and VAS for pain. Results: Fifty-two patients (16 males and 36 females, age: 63.9 ± 11.7 years, BMI: 28.8 ± 5.4 kg/m2) were followed for a mean of 68.7 (24.0 – 203.7) months postoperatively. Overall surgery satisfaction was 7.9 (arthroscopic) and 6.0 (open) (p = 0.178). 86% of patients treated arthroscopically reported feeling “slightly” or “much better” and 86% also reported improvement in their anterior groin pain, compared to 55% and 45% respectively treated openly. In the arthroscopic cohort, 64% reported that their hip flexion strength was “slightly ” or “much better”, compared to 36% treated openly. Average VAS pain score was 1.7 ± 2.7 at rest (arthroscopic: 1.1 ± 2.2, open: 3.3 ± 3.2, p = 0.0092) and 3.0 ± 1.3 (arthroscopic: 3.1 ± 1.3, open: 2.6 ± 1.1) with use. Mean postoperative Tegner score was 3.0 ± 1.3 (arthroscopic: 3.1 ± 1.3, open: 2.6 ± 1.1) compared to 2.3 ± 1.2 preoperatively (arthroscopic: 2.3 ± 1.3, open: 2.1 ± 1.1) (p = 0.0018). Mean post-operative mHHS and SANE score was 74.9 ± 21.6 (arthroscopic: 77.0 ± 19.0, open: 69.2 ± 26.9) and 69.7± 29.7 (arthroscopic: 70.9 ± 28.7, open: 66.7 ± 31.8) respectively. Conclusion: The results indicate that arthroscopic IPFL trends towards significantly improved pain, function, and satisfaction scores when compared to patients undergoing open IPFL, and should be considered when appropriate over an open IPFL given the less invasive nature of an arthroscopic procedure.

Abstract Purpose: 1) To report the clinical outcomes and reoperation rates of arthro- and endo-scopic iliopsoas release at short-term follow-up following ipsilateral total hip arthroplasty from two separate medical institutions, and 2) to evaluate whether demographic and radiographic parameters are associated with postoperative patient reported outcomes. Methods: Patients with iliopsoas tendinitis in the setting of prior THA that underwent arthroscopic iliopsoas fractional lengthening from 1988 – 2023 were reviewed at two academic institutions. Patients were included if they had minimum 12-month follow-up and were evaluated for preoperative anterior acetabular component overhang, surgery satisfaction, postoperative subjective hip flexion strength and anterior groin pain improvement, modified Harris Hip Score (mHHS), Single Assessment Numeric Evaluation (SANE) score, Tegner activity scale, visual analog scale (VAS), and revision hip arthroplasty. Results: Sixty hips in 58 patients (19 males, 39 females) were followed for a mean of 39.3 (12.0-105.9) months postoperatively. 77% of patients reported feeling “much” or “slightly better”, 75% reported improved anterior groin pain, and 60% reported improved subjective hip flexion strength. Surgery satisfaction was 7.2 ± 3.3 (scale of 0 to 10). Mean postoperative mHHS, VAS pain at rest, VAS pain with use, and SANE scores were 73.9 ± 19.4, 1.3 ± 2.4, 3.8 ± 2.9, and 71.9 ± 21.9 respectively. Preoperative anterior acetabular component overhang was 3.3 ± 6.5 mm and didn’t significantly correlate with postoperative PROs (p ≥ 0.45). Tegner score improved to 2.9 ± 1.4 from 2.5 ± 1.7 preoperatively (p = 0.0253). Three patients underwent revision arthroplasty at a mean of 25.3 (11.6 – 40.4) months postoperatively, with an acetabular component revision rate of 3.3%. Conclusions: Satisfactory outcomes and low revision arthroplasty rates were observed in patients undergoing arthroscopic iliopsoas lengthening following THA. There was no statistically significant relationship between anterior acetabular component overhang and final PROs. Level of Evidence: IV; Retrospective Case Series

ABSTRACTPurposeDouble‐level osteotomies (DLOs) have shown promising results for knee joint preservation, however, most ultimately progress in terms of degenerative disease resulting in conversion to total knee arthroplasty (TKA). Therefore, the purpose of this study was to examine the time to TKA conversion, long‐term clinical outcomes and revision rates of patients who have undergone TKA after prior ipsilateral DLO.MethodsPatients who underwent simultaneous or staged DLO and subsequently underwent conversion to TKA at a single academic institution from 1997 to 2022 were evaluated. The type of osteotomy performed (opening‐ vs. closing‐wedge), osteotomy hardware fixation, when and if osteotomy hardware was removed, implanted TKA components and revision rates were recorded. Postoperative outcomes, including Forgotten Joint Score‐12 (FJS‐12), Tegner Activity Scale score and subjective knee preference were also obtained.ResultsA total of 22 patients (24 knees) underwent TKA following DLO and were followed for an average of 26.1 ± 7.7 years. The average time from DLO to TKA conversion was 14.1 ± 6.5 years, with 70.8% of knees converting to TKA more than 10 years after DLO. The mean follow‐up after conversion to TKA was 12.0 ± 7.7 years. Only 12.5% of patients received a varus‐valgus or hinged‐constrained TKA. At the final follow‐up, the mean FJS‐12 was 75.8 ± 23.1, while the mean Tegner Activity Scale score was 2.5 ± 1.1. Seventy‐seven percent of patients had no subjective knee preference or preferred their DLO‐TKA knee. Only two knees (7.4%) underwent subsequent revision after index arthroplasty at a mean of 9.3 years postoperatively.ConclusionsA majority of DLOs (70.8%) converted to TKA after more than a decade. Subsequent TKA function was favorable as most patients had either no subjective knee preference or preferred their DLO‐TKA knee. This study demonstrates both long‐term joint preservation and uncompromised TKA function after prior DLO.Level of EvidenceLevel IV.

AimsThe purpose of this study was to directly compare the Modular Dual Mobility (MDM) Mobile Bearing Hip System (Stryker, USA) and large femoral heads (LFHs) in revision total hip arthroplasties (THAs) at mid-term follow-up, with specific emphasis on survival free of re-revision for dislocation, any re-revision, dislocation, and the risk of metal-related complications.MethodsWe identified 299 revision THAs performed at a single tertiary care academic institution from March 2011 to July 2014. Aseptic loosening of the acetabular component (n = 65), dislocation (n = 58), and reimplantation as part of a two-stage exchange protocol (n = 57) were the most common reasons for index revision. MDM constructs were used in 123 cases, and LFHs were used in 176 cases. Mean age was 66 years (28 to 93), mean BMI was 31 kg/m2 (18 to 55), and 45% (n = 136) were female. Mean follow-up was seven years (2 to 12).ResultsThe ten-year survival free of re-revision for dislocation was 99% (95% CI 95 to 100) in the MDM cohort and 91% (95% CI 84 to 96) in the LFH cohort, with a significantly increased risk of re-revision for dislocation in the LFH cohort (HR 7.1 (95% CI 1.3 to 40.8); p = 0.023). The ten-year survival free of any re-revision was 92% (95% CI 82 to 99%) in the MDM cohort and 84% (95% CI 74 to 90) in the LFH cohort with a significantly increased risk of any re-revision in the LFH cohort (HR 2.6 (95% CI 1.1 to 5.9); p = 0.024). The ten-year survival free of any dislocation was 95% (95% CI 85 to 99) in the MDM cohort and 87% (95% CI 78 to 92) in the LFH cohort with a significantly increased risk of any dislocation in the LFH cohort (HR 2.7 (95% CI 1.1 to 6.3); p = 0.028). There were no re-revisions or reoperations for metallosis or corrosion in the MDM cohort.ConclusionIn this head-to-head comparison, revision THAs with a MDM construct safely and effectively lowered the risk of re-revision for dislocation, any re-revision, and any dislocation compared to LFH at mid-term follow-up. There were no re-revisions or reoperations for metallosis or corrosion in the MDM cohort.Cite this article: Bone Joint J 2025;107-B(1):58–64.

Background: The direct anterior approach (DAA) is a popular approach for primary total hip arthroplasty (THA). However, the contemporary outcomes for DAA THA need further elucidation. Therefore, we aimed to describe implant survivorship, complications, and clinical outcomes after DAA THA. Methods: From our multi-institutional total joint registry, 3,184 patients who had undergone 3,698 primary DAA THA between 2010 and 2019 were identified. The identified patients had a mean age of 65 years and a mean body mass index (BMI) of 29 kg/m 2 , and 53% of patients were female. The indications for revision and reoperation and the incidence of complications were collected and analyzed. Potential risk factors, including age, sex, BMI, and high-volume compared with low-volume operating surgeons, were examined. Descriptive statistics and Kaplan-Meier survivorship with Cox regression analyses were performed. Results: At 10 years following primary DAA THA, the cohort had 96% (95% confidence interval [CI], 95% to 98%) survivorship free of any revision and 94% (95% CI, 92% to 96%) survivorship free of any reoperation. The leading indications for revision were periprosthetic joint infection (PJI) (n = 24; 5-year cumulative incidence, 0.93% [95% CI, 0.6% to 1.5%]), periprosthetic fracture (n = 20; 5-year cumulative incidence, 0.62% [95% CI, 0.4% to 1.0%]), and aseptic loosening (n = 14; 11 femoral, 3 acetabular; 5-year cumulative incidence, 0.84% [95% CI, 0.5% to 1.5%]). A BMI of ≥40 kg/m 2 was found to be significantly associated with PJI (hazard ratio [HR], 6.4; p < 0.001), reoperation (HR, 3.5; p < 0.001), and nonoperative complications (HR, 2.3; p = 0.018). Survivorship free of recurrent instability was 99.6% (95% CI, 99.4% to 99.8%) at 5 and 10 years, and the cumulative incidence of revision for instability was 0.14% at 5 years. Conclusions: In one of the largest published series to date, survivorship following DAA THA was satisfactory at early to intermediate follow-up. The leading indications for revision were PJI, periprosthetic fracture, and aseptic loosening. Instability after DAA THA was uncommon and infrequently led to revision. As a note of caution, a BMI of ≥40 kg/m 2 was identified as a risk factor for adverse outcome after DAA THA. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.