Taunton, Michael J.

Aims Two-stage exchange arthroplasty with an antibiotic-eluting cement spacer remains the predominant strategy in the USA for managing chronic periprosthetic joint infection (PJI) following total hip arthroplasty (THA). The aim of this study was to evaluate a commercially available, partially intraoperatively fabricated articulating high-dose antibiotic cement spacer, focusing on survival, complications, and patient-reported outcomes. Methods A total of 298 patients (302 THAs) underwent two-stage exchange arthroplasty for PJI using a specific articulating antibiotic spacer between August 2005 and May 2022. Patients with a previous failed two-stage exchange were excluded, although 121 THAs (302, 40%) had undergone previous PJI-related procedures. The mean age of the patients was 65 years (SD 11), the mean BMI was 32 kg/m 2 (SD 7), and 116 (38%) were female. Most patients were classified as McPherson host B (158; 52%) and limb grade 2 (165; 55%), and 265 (88%) met the 2011 Musculoskeletal Infection Society criteria. The mean follow-up was six years (2 to 16). Results At five years after reimplantation, survival free of reinfection, aseptic rerevision, any rerevision, or any reoperation were 89% (95% CI 85.2 to 93.1), 93% (95% CI 89.3 to 96.1), 86% (95% CI 81.3 to 90.3), and 80% (95% CI 74.7 to 84.9), respectively. Dislocation accounted for most aseptic rerevisions (15/20). McPherson host C (HR 3.7 (95% CI 1.4 to 9.6); p = 0.007) and limb grade 3 (HR 3.3 (95% CI 1.0 to 11.1); p = 0.049) were significantly associated with an increased risk of reinfection. The mean Harris Hip Score at the latest follow-up was 76 (29 to 100). A total of 17 patients underwent revision or removal of a spacer for concerns about persistent infection and two for dislocation of the spacer. Eight patients underwent a non-rerevision reoperation during the spacer interval for wound drainage (n = 5), dislocation of the spacer (n = 2), and perispacer fracture (n = 1). A total of 26 spacer-related complications were treated nonoperatively (15 perispacer fractures, 11 dislocations). Dislocation of the spacer was strongly associated with dislocation after reimplantation (HR 6.2 (95% CI 2.3 to 16.9); p < 0.001). Conclusion This commercially available, partially intraoperatively fabricated articulating spacer showed excellent reinfection-free five-year survival (89%). Spacer-related fracture and dislocation each occurred in 5% of patients. Dislocation of the spacer significantly increased the risk of dislocation following reimplantation, supporting the use of higher-stability bearings in these high-risk patients. Cite this article: Bone Joint J 2026;108-B(9):1104–1112.

The total number of total hip arthroplasties performed each year is expected to increase significantly over the coming decades. As a result, an increasing number of young patients are undergoing total hip arthroplasty while similarly, a growing subset of active elderly patients desire to return to sports or high-impact activity after surgery. Patients are typically provided restrictions and activities to avoid following surgery. For these patients, there is no clear consensus or guidelines regarding whether they should limit their activity level postoperatively and in particular, if returning to high-impact exercise increases their risk of complications and subsequent revision surgery. This article will discuss the most common complications after total hip arthroplasty and whether patients who return to sports or a high-impact activity after surgery may be more predisposed to these complications in comparison to their more sedentary peers.

We previously reported 5-year results of 57 patients with major acetabular defects (Paprosky 2B through 3B) who underwent full (31) or half (26) cup-cage reconstructions. This study provides an update with 8.8-year mean follow-up. The 10-year cumulative incidence of and survivorship free from revision, reoperation, and complications were estimated. The 10-year cumulative incidence of revision was 14% for full and 12% for half constructs. The incidence of revision for aseptic loosening was 4.3% and 4.6%, respectively. The 10-year survivorship free from aseptic loosening for patients with pelvic discontinuity was 88.9% (95% confidence interval [CI], 70.6% to 100%) and 85.7% (95% CI, 61.8% to 100%), respectively; no patient without pelvic discontinuity required revision for aseptic loosening. The 10-year cumulative incidence of complications was 42% for all patients, including a 15% incidence of dislocation. Thus, both full and half cup-cage constructs provided durable fixation for complex acetabular bone loss at 10 years, although dislocation remains a concern. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: Prior studies have reported higher rates of periprosthetic fracture, superficial infection, and neurologic deficit with the direct anterior approach (DAA), and higher rates of dislocation with the posterior approach (PA) for total hip arthroplasty (THA). Despite these differences, the overall clinical burden of complications between approaches remains unclear. The purpose of this study was to compare the profiles, severity, impact, and resolution of 5 clinically important complications between DAA and PA THA. Methods: A retrospective review was conducted of 11,783 consecutive primary THAs performed between 2010 and 2021 across 3 centers within a single healthcare system, using either the DAA (n = 4,451) or the PA (n = 7,332). Complications assessed included dislocation, infection, periprosthetic fracture (PPFx), aseptic loosening, and neurologic deficit. Severity was graded using the Clavien-Dindo classification (I = minor, V = death). Impact was defined by reoperation burden, and outcomes were categorized as resolved or persistent. Kaplan-Meier survivorship and propensity-weighted Cox proportional hazards models were used to compare complication risk. Results: The overall 1-year risk of surgical complications did not differ between DAA and PA (hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.75-1.06; p = 0.208). Dislocation occurred more frequently with PA THA than DAA THA (1.9% vs. 0.4%; HR, 5.20; 95% CI, 3.04-8.90; p < 0.001). Superficial infections were more frequent with the DAA (1.6% vs. 0.8%; HR, 2.43; 95% CI, 1.68-3.53; p < 0.001). The risk of deep infection, PPFx, aseptic loosening, and neurologic deficit did not differ significantly between approaches. Among patients with complications, the proportion classified as severe (Clavien-Dindo III–V) was similar, and adjusted analyses showed no difference in the odds of severe complications (adjusted odds ratio 1.34 for PA vs DAA; 95% CI, 0.95-1.91; p = 0.099). Complication impact and resolution were likewise comparable. Conclusion: Although the profile of complications differed between DAA and PA THA, the severity, early clinical impact, and resolution of complications appeared similar. Notably, DAA was associated with a lower risk of dislocation and a higher risk of superficial infection compared with PA THA. Level of Evidence: Level III , Retrospective Comparative Study. See Instructions for Authors for a complete description of levels of evidence.

Purpose To investigate outcomes among patients undergoing total hip arthroplasty after hip arthroscopy (HA‐THA) compared with a matched cohort undergoing primary THA without prior arthroscopy (Only‐THA). Methods Patients who underwent THA after primary hip arthroscopic labral repair from 2009 to 2022 at a single institution were identified. Cases were propensity‐matched 1:4 to primary THA controls by age at THA, sex, body mass index (BMI), surgical approach, and year of surgery. At minimum 2‐year follow‐up, patient‐reported outcomes (PROs)—Forgotten Joint Score (FJS), modified Harris Hip Score (mHHS), and Hip Disability and Osteoarthritis Outcome Score Pain (HOOS‐Pain)—were analyzed. Results Sixty‐two hips (age: 47.5 ± 9.3 years, BMI: 29.7 ± 6.2 kg/m 2 ) were matched to 248 Only‐THA hips (age: 47.9 ± 10 years, BMI: 29.5 ± 5.8 kg/m 2 ). Although both HA‐THA and Only‐THA patients showed significant ( P < .001) postoperative improvements in PROs, HA‐THA patients reported significantly lower postoperative FJS, mHHS, HOOS‐Pain, and inferior Visual Analog Scale pain scores ( P < .001) compared with Only‐THA controls. A cohort‐specific minimal clinical important difference for mHHS was calculated as 9.6 points, with 75.7% of HA‐THA and 87.5% Only‐THA patients achieving this threshold ( P = . 077). At mean 6.6 ± 3.3 years follow‐up, HA‐THA patients with preoperative Tönnis grades 1 reported significantly decreased FJS, mHHS, and HOOS‐Pain compared with HA‐THA patients with preoperative Tönnis grade 2‐3 ( P ≤ .05). HA‐THA patients with Tönnis grade 1 also exhibited worse PROs ( P < .001) compared with Only‐THA controls. Although there were no differences in complication rates between HA‐THA and Only‐THA patients (8% vs. 5%, P = .49), all‐cause reoperation was greater amongst HA‐THA (10% vs. 2%, P = .01). Conclusions Patients undergoing THA after prior hip arthroscopy showed modestly inferior subjective outcomes at mid‐term follow up compared with an age‐matched cohort without prior arthroscopy. Although both groups showed meaningful improvement, a smaller proportion of HA‐THA patients achieved the cohort‐specific MCID for mHHS compared with Only‐THA controls. Level of Evidence Level III, retrospective cohort study.

Background: Total knee arthroplasty (TKA) is the treatment of choice for end-stage knee osteoarthritis in many patients. In younger patients with predominantly medial compartment disease, high tibial osteotomy (HTO) is performed as a joint-preserving treatment. However, concerns remain regarding potentially compromised outcomes of TKA after previous HTO given the axial deviation, osteotomy site, secondary surgery, previous hardware, and instrumentation. Therefore, this study compared long-term implant survival, revision, and infection rates, and patient-reported outcomes between patients undergoing TKA after HTO and matched TKA-only controls. Methods: Postoperative complications and revision surgeries were prospectively recorded in patients who underwent TKA from 2000 to 2023 at a single academic center. Patients with previous ipsilateral HTO formed the study group and were propensity matched 1:2 to TKA-only patients without a previous osteotomy based on age, sex, and body mass index. Knee Society Scores (KSS) were collected prospectively. Implant survivorship was analyzed using Kaplan-Meier survival curves and Cox proportional hazards models. Results: The study included 134 HTO-TKA and 268 matched TKA-only patients, with a mean follow-up of 10.5 ± 6.4 years (range: 0-24 years) after TKA. Both groups showed significant postoperative improvements in KSS (p < 0.02) with comparable clinical outcomes (HTO-TKA: 79.0 (6.0), TKA-only: 79.0 (11.8)). Revision arthroplasty rates were 5.2% for HTO-TKA and 4.5% for TKA-only (p = 0.69); the mean time to revision was 8.1 ± 8.7 years vs. 4.4 ± 3.5 years, respectively (p = 0.30). Infection rates were 2.2% and 1.1%, respectively (p = 0.74). Conclusions: Revision and infection rates were comparable between HTO-TKA and matched TKA-only patients, with no statistically significant differences. Our findings demonstrate comparable patient-reported outcomes in both groups. These findings indicate that a previous HTO does not adversely affect TKA implant longevity or clinical outcomes when compared with matched primary TKA patients within the US population. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Introduction In recent years collared femoral stems have been increasingly utilized in total hip arthroplasty (THA) for their ability to improve rotational stability, metaphyseal load transfer, and prevent periprosthetic femoral fracture (PFF). While literature has demonstrated their benefit over collarless stems, the clinical and biomechanical implications of a postoperative collar–calcar gap (CCG) after implantation remain incompletely understood. Objective The purpose of this scoping review was to evaluate existing literature around CCG in primary THA. Methods A PRISMA Scoping Review literature search was conducted across Ovid MEDLINE, Embase, Cochrane CENTRAL, and Scopus databases. Studies were included if they reported CCG incidence, subsidence, remodeling, or biomechanical performance in primary THA. Two independent reviewers screened studies and extracted data, and clinical study quality was assessed using the Newcastle–Ottawa Scale. Results A total of 408 studies were identified and 11 met inclusion criteria. The incidence of postoperative CCG varied from 18.7% to 53.9%. Most gaps demonstrated closure over time (66–76%). Biomechanical and finite element studies showed improved stability, reduced micromotion, and decreased periprosthetic fracture risk when direct collar–calcar contact was achieved. In contrast, stems with persistent gaps demonstrated increased subsidence (up to 19% vs 1.3%) and biomechanical behavior comparable to collarless designs. Conclusion CCG is common following THA. The majority of gaps resolve, however biomechanical evidence demonstrates that the advantages of collared stems depend on calcar contact. Preventing CCG may optimize early implant stability, though surgical technique must balance mechanical engagement with preservation of proximal femoral bone stock.

Abstract Purpose The purpose of this systematic review was to compare the inter‐ and intra‐observer reliability of Kellgren–Lawrence (KL) grading versus minimum joint space width (mJSW) measurement on knee radiographs, and to examine the influence of rater type, radiographic view and atlas‐based training. Methods A systematic search of PubMed/MEDLINE, Embase, Scopus and Web of Science was conducted through July 2025 following Preferred Reporting Items for Systematic reviews and Meta‐Analyses (PRISMA) guidelines. Studies reporting inter‐ and/or intra‐observer reliability for KL or mJSW on standard knee radiographs were included. Extracted data included kappa ( κ ) and intraclass correlation coefficient (ICC) values, rater expertise, radiographic view and atlas usage. Raters were categorized as expert, trainee/non‐expert or artificial intelligence (AI)‐assisted/automated. Results Twenty‐four studies (10,394 radiographs) met the inclusion criteria. Inter‐observer reliability was generally higher for mJSW (mean ICC = 0.82 ± 0.17) compared with KL (mean k = 0.72 ± 0.17), with similar trends observed for intra‐observer reliability. Experts and AI‐assisted systems outperformed trainees/non‐experts for both metrics. Reliability improved with semiflexed posteroanterior/Rosenberg views and atlas‐guided training. Conclusion This systematic review demonstrates that mJSW measurement generally shows higher reproducibility than KL grading. Reliability improved with expertise, standardized imaging and structured training, and AI‐assisted approaches performed comparably to expert raters. Quantitative mJSW should complement KL grading, particularly when combined with alignment measures, to enhance consistency and clinical relevance of radiographic assessment. Level of Evidence Level III.

Background: We aimed to develop automated data extraction pipelines with large language models (LLMs) to extract registry data from total hip arthroplasty (THA) operative notes and compare the performance with that of existing natural language processing (NLP) algorithms. Methods: We randomly sampled 1,000 primary THA cases from our institutional registry. Two human annotators manually reviewed each operative note for 3 data points: surgical approach, bearing surface, and fixation technique. All labeled THA notes were split into the development set (n = 239) and the testing set (n = 719). We developed a custom data extraction pipeline for each data point by combining an iteratively customized prompt with an LLM. The performance was compared with that of existing rules-based NLP algorithms. Results: The accuracy of LLMs was superior to that of NLP algorithms for all data points: surgical approach (96% compared with 94%), bearing surface (89% compared with 74%), and fixation technique (96% compared with 95%). Furthermore, the LLM accurately inferred the bearing surface for 80% of the notes that were ambiguous about the bearing surface. Conclusions: We developed LLM pipelines for extracting 3 registry-relevant data points from THA operative notes, demonstrating superior performance to existing NLP algorithms. Clinical Relevance: LLMs have the potential to impact clinical care, including the evaluation of electronic medical record free-text data. As registries serve as a cornerstone of orthopaedic evidence, this work demonstrates promise for LLMs to simplify, improve, and democratize the construction of registry databases from operative notes.

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.