Berry, Daniel J

Aims An angular proximal femoral deformity, in association with osteoarthritis (OA) of the hip, considerably increases the technical complexity of primary total hip arthroplasty (THA). The aims of this study were to determine the long-term implant survival, the risk factors for failure, complications, and clinical outcomes of contemporary primary THA in this difficult group of patients. Methods Our institutional total joint registry was used to identify 119 primary THAs performed in 108 patients with an angular proximal femoral deformity, between January 1997 and September 2017. The deformity was related to a previous femoral osteotomy in 102 THAs (86%), and developmental or metabolic disorders in 17 THAs (14%). A total of 62 hips (53%) had a predominantly varus deformity. The mean age of the patients was 44 years (SD 13), their mean BMI was 29 kg/m 2 (SD 6), and 70 (59%) were female. An uncemented femoral component with metaphyseal fixation was used in 35 THAs (30%), an uncemented femoral component with diaphyseal fixation in 34 (29%), an uncemented modular femoral component with a metaphyseal fixation sleeve in 29 (24%), and a cemented femoral component in 21 (18%). Simultaneous corrective femoral osteotomy was performed in 22 THAs (18%). Kaplan-Meier survival and Harris Hip Scores (HHSs) were reported. The mean follow-up was eight years (2 to 22). Results The ten-year survival free of femoral loosening, any femoral revision, any revision and any reoperation was 95%, 93%, 90%, and 88%, respectively. A total of 13 revisions were undertaken, for aseptic femoral loosening in three, fracture of the femoral component in two, dislocation in two, aseptic acetabular loosening in two, polyethylene liner exchange in two, and infection in two. A preoperative varus deformity was associated with a higher risk of any revision (hazard ratio (HR) 12.5, p = 0.020), and those with a simultaneous osteotomy had a higher risk of any reoperation (HR 3.6, p = 0.023). The mean HHSs improved significantly from 52 preoperatively to 82 at ten years (p < 0.001). Conclusion In the largest series to date of primary THAs in patients with hip OA and an angular proximal femoral deformity, we found a good ten-year survival free from any revision. Varus deformities, particularly those treated with a simultaneous osteotomy due to the magnitude or location of the deformity, had a higher rate of further surgery. Cite this article: Bone Joint J 2025;107-B(6 Supple B):101–108.

Background: Periprosthetic tibial fractures around a total knee replacement (TKR) remain challenging to manage, with little published information for guidance. The purpose of this study was to review the types, management techniques, and outcomes of periprosthetic tibial fractures in the largest series to date. Methods: We identified 300 periprosthetic tibial fractures (285 patients) around a TKR (43% in primary TKRs and 57% in revision TKRs) sustained between 1996 and 2020. Fractures were classified according to Felix et al. as Type I (tibial plateau), Type II (adjacent to stem), Type III (distal to stem), or Type IV (tibial tubercle), with subtypes A (well-fixed component), B (loose component), and C (intraoperative fracture). Of the fractures in this study, 53% were Type I, 24% were Type II, 16% were Type III, and 8% were Type IV. A total of 46% of fractures occurred intraoperatively, and 54% of fractures occurred postoperatively (61% subtype A, 39% subtype B). The mean patient age at fracture was 67 years, and 64% of patients were female. The mean follow-up was 6 years. Results: The intraoperative fracture incidence was 1.40% in revision TKRs and 0.10% in primary TKRs. Among intraoperative fractures, the 2-year survivorship free from tibial component revision was highest in Type I (100%) and lowest in Type IV (67%) (p < 0.001). For postoperative fractures, the 2-year survivorship free from any reoperation was 29% and the 2-year survivorship free from tibial component revision was 51%. Type-I postoperative fractures had the lowest 2-year survivorship free from tibial component revision (10%), whereas Type-III fractures had the highest survivorship (88%) (p < 0.001). Conclusions: Intraoperative periprosthetic fracture of the tibia was fourteenfold more likely in revision TKRs compared with primary TKRs. Among all intraoperative fractures, Type-I fractures were well-tolerated, with 100% survivorship free from tibial component revision at 2 years. Conversely, Type-I postoperative fractures had only 10% survivorship at 2 years. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Background: Total hip arthroplasty (THA) effectively restores mobility, reduces pain, and enhances the quality of life of patients of all ages. Despite its benefits, concerns regarding the long-term effects of high-impact activities and sports on implant longevity require further study. This study investigated the effect of activity level on long-term radiographic wear of highly cross-linked polyethylene (HXLPE) in young patients undergoing THA. Methods: Between 1999 and 2008, 785 patients (909 hips) aged ≤50 underwent primary THA using first-generation HXLPE liners from 4 different vendors with either metal or ceramic heads. Functional activity and participation questionnaires, including the Hip Injury and Osteoarthritis Outcome Score (HOOS Jr), University of California Los Angeles (UCLA) activity scale, and High-Activity Arthroplasty Score (HAAS), were surveyed in 2018 to 2019. The response rate was 44%. Radiographic linear wear rates were measured using the ROMAN software in patients who had completed questionnaires and had radiographs taken at least 10 years apart, leaving a final cohort of 249 patients (284 hips). Multivariate analyses were performed to determine the relationship between HXLPE wear rates and activity scores. Results: At the time of the survey, approximately 10% of the patients performed high-impact activities not-recommended by consensus guidelines. The HXLPE linear wear rate was 0.036 mm/year (SD: 0.026). Patients with higher activity levels, as measured on the continuous UCLA/HAAS activity scale, did not exhibit increased wear (β = -0.0009; p = 0.31). Stair climbing was correlated with increased wear rates (β = 0.0066; p = 0.004), whereas walking (β = 0.0005; p = 0.66) and running (β = 0.0017; p = 0.30) were not significantly correlated. Patients performing nonrecommended activities did not show increased wear rates compared with those performing recommended activities (β = 0.0063; p = 0.19). Conclusions: Linear wear rates of first-generation HXLPE were not related to functional activity or participation in high-impact activities. Future research should include longitudinal assessments of activity levels and data on other potential complications related to high-impact sports to provide robust evidence regarding recommended activity level postoperatively. Level of Evidence: Level III , Retrospective Comparative Study. See Instructions for Authors for a complete description of levels of evidence.

Background: Traditional Medicare (TM) claims data are widely used by researchers and registries to report survivorship following total knee arthroplasty (TKA). The purpose of the present study was to investigate whether the mass exodus of patients from TM to Medicare Advantage (MA) has compromised the fidelity of TM data. Methods: We identified 11,717 Medicare-eligible patients (15,282 knees) who had undergone primary TKA from 2000 to 2020 at a single institution. Insurance type was analyzed, and 84% of TKAs were covered by TM. The rates of survivorship free from revision or reoperation were calculated for patients with TM coverage. The same survivorship end points were recalculated after censoring of patients who transitioned to MA after primary TKA, thereby modeling the impact of losing patients from the TM dataset. Differences in survivorship were compared. The mean duration of follow-up was 10 years. Results: From 2000 to 2020, there was a decrease in TM insurance (from 94% to 68%) and a corresponding increase in MA insurance (from 0% to 19%) among patients undergoing TKA. Following TKA, 25% of patients with TM coverage switched to MA. For patients with TM at the time of surgery, the 15-year rates of survivorship free from any reoperation or revision were 90% and 96%, respectively. When patients were censored upon transition from TM to MA, the 15-year rates of survivorship free from any reoperation (92% versus 90%; hazard ratio [HR] = 1.2; p = 0.001) or any revision (97% versus 96%; HR = 1.3; p = 0.002) were significantly higher. Conclusions: One in 4 patients left TM for MA after primary TKA, effectively making them lost to follow-up within TM datasets. The mass exodus of patients out of TM resulted in falsely elevated estimates of survivorship free from reoperation and from revision, with increasing divergence in survivorship over time, when MA data were excluded. As MA continues to grow, efforts to incorporate these data will become increasingly important. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Experimental analyses of knee joint contractures have traditionally utilized a 6-month rabbit model as the gold standard. However, this model is time-intensive and costly. The purpose of this study was to develop an abbreviated rabbit model of knee contractures and compare it to the well-established longer model. Twenty female New Zealand White rabbits were divided into two equal groups and prospectively studied to assess knee passive extension angles (PEA), contracture angles (CA), and terminal posterior capsular stiffness. Experimental knees were immobilized for either 4 weeks ( n = 10) with an 8-week remobilization period in the abbreviated model (i.e., 3 months) or for 8 weeks ( n = 10) with a 16-week remobilization period in the standard model (i.e., 6 months). PEAs were assessed at remobilization and several time points using differing vertical forces. At sacrifice, terminal biomechanical data were collected to assess posterior capsular stiffness. Analysis of PEAs in live animals at each torque value and time point demonstrated increased PEAs and decreased CAs in the 3-month abbreviated model as compared to the 6-month standard model. At sacrifice, biomechanical analysis demonstrated that the posterior capsules of the 3-month experimental limbs were significantly more stiff than the contralateral limb (2.4 vs. 0.05 Ncm/°, p < 0.0001), but significantly less stiff compared to the 6-month experimental limbs (2.4 vs. 4.7 Ncm/°, p < 0.0001). Our study suggests that the 6-month standard rabbit knee model of arthrofibrosis should continue to be used in the laboratory assessment of arthrofibrosis. However, the abbreviated model may be beneficial under selected experimental conditions.

AimsTo evaluate the role of autophagy in primary knee fibroblasts undergoing myofibroblast differentiation as an in vitro model of arthrofibrosis, a complication after total knee arthroplasty characterized by aberrant intra-articular scar tissue formation and limited range of motion.MethodsWe conducted a therapeutic screen of autophagic-modulating therapies in primary human knee fibroblasts undergoing transforming growth factor-beta 1 (TGF-β1)-mediated myofibroblast differentiation. Autophagy was induced pharmacologically with rapamycin or by amino acid deprivation. Picrosirius red staining was performed to quantify collagen deposition. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were conducted to evaluate fibrotic gene expression levels.ResultsRapamycin, an mTOR complex 1 (mTORC1) inhibitor and autophagy inducer, reduced TGF-β1-mediated collagen deposition. Interestingly, we simultaneously report that myofibrogenic genes, including ACTA2, were highly upregulated following rapamycin-TGF-β1 treatment. When autophagy was induced through amino acid deprivation, we demonstrated suppressed extracellular matrix levels, fibrotic gene expression (e.g. ACTA2), and SMAD2 phosphorylation levels in TGF-β1-stimulated fibroblasts.ConclusionOur findings demonstrate that the induction of cellular autophagy suppresses TGF-β1-induced collagen deposition in primary human knee fibroblasts. Taken together, these data suggest that cellular autophagy may be prophylactic against the pathogenesis of arthrofibrosis.Cite this article: Bone Joint Res 2025;14(4):328–337.

AimsContemporary outcomes of total femoral arthroplasties (TFAs) in the non-oncological setting are limited. This study aimed to assess implant survival free from revision and reoperation, clinical outcomes, and radiological results associated with TFAs for non-oncological conditions.MethodsWe identified 24 patients who received TFAs between 1 January 2007 and 31 December 2021 through our institutional total joint registry. The patients’ mean age was 66 years (48 to 83), mean BMI was 33 kg/m2 (21 to 54), and median follow-up was four years (IQR 2 to 5). Bearings used included eight flat-faced polyethylene bearings, seven dual-mobility constructs, six constrained liners, and three face-changing liners. Of the 24 patients, 17 had a previously documented periprosthetic joint infection (PJI) and 12 were treated with chronic antibiotic suppression following their TFAs.ResultsThe two-, five-, and ten-year survivals free of any revision were 66%, 51%, and 34%, respectively. There were 12 revisions: five for hip dislocation, four for PJI, one for aseptic tibial loosening, one for prosthetic knee dislocation, and one for acetabular loosening with pelvic discontinuity. The two-, five-, and ten-year survivals free of any reoperation were 53%, 47%, and 34%, respectively. In addition to the stated TFA revisions, one patient required open reduction of a hip dislocation, and two patients required superficial irrigation and debridement procedures for wound complications. Mean Harris Hip Scores improved from a mean score of 48 to 69 (p = 0.002), and Knee Society Scores improved from a mean score of 56 to 71 (p = 0.110). At final follow-up, 20 patients had TFAs in situ, but four patients had been treated with hip disarticulation due to recalcitrant infection. All but one tibial and all non-revised acetabular components were radiologically well-fixed at final follow-up.ConclusionThe use of TFAs in the non-oncological setting, mostly for salvage of multiply revised hips with previous PJI, had a low five-year survival free from any revision of 51%, mostly for hip dislocation and infection. Nevertheless, clinical outcomes improved in this challenging cohort of patients.Cite this article: Bone Joint J 2025;107-B(4):449–454.

Background: Many surgeons use body mass index (BMI) cutoffs when offering total hip arthroplasty (THA). However, little is known about who loses weight before THA, and if weight loss improves outcomes. This study determined how many patients lost weight before primary THA, identified predictors of preoperative weight loss, and evaluated whether preoperative weight loss was associated with improved outcomes. Methods: Among 53,038 primary THAs that were performed between 2002 and 2019, we identified 2,463 patients who had a BMI of ≥30 kg/m 2 (measured 1 to 24 months before surgery) and had their weight measured at the time of surgery. The mean age was 66 years; 47% were women. The mean BMI was 35 kg/m 2 . Nonparametric models evaluated potential associations with weight loss. Univariable and multivariable logistic regression and Cox proportional hazards models evaluated the impact of preoperative weight change on hospital length of stay, discharge disposition, operative time, periprosthetic joint infection (PJI), complications, revision, and reoperation. The mean follow-up was 5 years. Results: Overall, 17% of the patients gained >5 pounds (2.27 kg), 38% maintained their weight, 16% lost 5 to <10 pounds (4.54 kg), 17% lost 10 to <20 pounds (9.07 kg), and 12% lost ≥20 pounds before THA. Only 28% of patients with a preoperative BMI of ≥40 kg/m 2 achieved a BMI of <40 kg/m 2 by the time of surgery; those who did required a mean of 1.3 years to lose the weight. In multivariable analyses, there were no significant improvements in operative time, length of stay, and discharge disposition, or survivorship free of PJI, complication, revision, or reoperation for any weight-loss category when compared with those who maintained their weight. Conclusions: Only 12% of patients lost ≥20 pounds, and only 28% of patients with a BMI of ≥40 kg/m 2 achieved a BMI of <40 kg/m 2 before primary THA. There was no decrease in complications, revisions, or reoperations for any preoperative weight-loss category when compared with those who maintained their weight. While weight loss benefits overall health, the results of this study call into question whether preoperative weight loss alone is enough to reduce postoperative complications for most patients. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Background: The relative advantages and disadvantages of 2-stage versus 1-stage management of infection following total hip arthroplasty (THA) are the current subject of intense debate. To understand the merits of each approach, detailed information on the short and, importantly, longer-term outcomes of each must be known. The purpose of the present study was to assess the long-term results of 2-stage exchange arthroplasty following THA in one of the largest series to date. Methods: We identified 331 periprosthetic joint infections (PJIs) that had been treated with a 2-stage exchange arthroplasty between 1993 and 2021 at a single institution. Patients were excluded if they had had prior treatment for infection. The mean age at the time of reimplantation was 66 years, 38% of the patients were female, and the mean body mass index (BMI) was 30 kg/m 2 . The diagnosis of PJI was based on the 2011 Musculoskeletal Infection Society criteria. A competing-risk model accounting for death was utilized. The mean duration of follow-up was 8 years. Results: The cumulative incidence of reinfection was 7% at 1 year and 11% at 5 and 10 years. Factors predictive of reinfection included BMI ≥30 kg/m 2 (hazard ratio [HR] = 2; p = 0.049) and the need for a spacer exchange (HR = 3.2; p = 0.006). The cumulative incidence of any revision was 13% at 5 and 10 years. The cumulative incidence of aseptic revision was 3% at 1 year, 7% at 5 years, and 8% at 10 years. Dislocation occurred in 33 hips (11% at 10 years); 15 (45%) required revision. Factors predictive of dislocation were female sex (HR = 2; p = 0.047) and BMI <30 kg/m 2 (HR = 3; p = 0.02). The mean Harris hip score (HHS) improved from 54 to 75 at 10 years. Conclusions: In this series of 331 two-stage exchange arthroplasties that were performed for the treatment of infection, we found a low rate of aseptic revision (8%) and a low rate of reinfection (11%) at 10 years. These long-term mechanical and infection data must be kept in mind when considering a paradigm shift to 1-stage exchanges. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.