Search Results (1,035)

A clinical observation of a previously asymptomatic native knee developing a relevant coronal alignment change after total hip arthroplasty (THA) motivated this research. This raised the question of whether the native knee morphology could influence the response to biomechanical changes elsewhere in the lower limb. First, we developed a simplified finite element model incorporating the Coronal Plane Alignment of the Knee (CPAK) classification. We developed a simplified model of the knee, where we represented the lateral distal femoral angle (LDFA) by physically rotating the femur, and to avoid remodeling the tibia coronal plane for each simulation, we represented the medial proximal tibial angle (MPTA) by adjusting the neutral angle of the joint (the angle at which the joint generates no reaction force). This allowed for quick parametric iteration over the CPAK input space, showing which type of knees were more vulnerable to extreme valgus (CPAK III) and varus (CPAK VII) due to their morphology. The simplicity of this model will also enable users with less technical expertise to quickly obtain insights into specific knee morphologies, without requiring deep knowledge about finite element modeling. This existing model lays the foundation for later work, with a deeper look into how changes to hip morphology build on the pre-existing tendencies to varus and valgus. Full article

Objective: This study aimed to analyze the incidence and multifactorial causes of dislocation following primary total hip arthroplasty (THA) and to evaluate current surgical strategies for the prevention and management of this complication. Methods: This retrospective study included 1066 hips (median age 57 years; 805 females and 261 males) that underwent primary THA performed by a single surgeon between 1996 and 2025. The median follow-up duration of the patients was 46 months (min: 6, max: 357 months), and 68.9% had primary coxarthrosis, while 31.1% had secondary coxarthrosis. In this study, the effects of dislocation causes, age, gender, femoral head size, liner angle, posterior capsular repair, type of anesthesia, fixation method of the prosthesis, etiology, and surgical experience (distribution by years) on dislocation were statistically analyzed. Results: The analysis revealed that 44 of the 1066 hips (4.1%) developed a dislocation. The most common causes of dislocation were identified as femoral offset error (40.91%) and acetabular component malposition (31.82%). A statistically significant correlation was found between dislocation development and gender (p < 0.001) and femoral head diameter (p = 0.006); the dislocation rate was higher in male patients (8.0%) than in female patients (2.9%). A marked reduction in dislocation rates (1.6%) was observed following the routine use of large-diameter femoral heads (32–36 mm). The highest dislocation rate was observed during the early years of surgical experience (1996–2000, 6.8%). No statistically significant differences were found between dislocation development and age (p = 0.055), type of anesthesia, type of prosthesis, liner angle, and secondary etiological factors (p > 0.05). Conclusions: Instability developing after primary THA is a multifactorial complication. In our study, inadequate femoral offset restoration and acetabular component malposition were identified as the most common mechanical causes of dislocation. Male gender was significantly associated with an increased risk of dislocation, whereas the use of larger femoral head diameters was associated with lower dislocation rates. Our findings suggest that meticulous preoperative planning, accurate component positioning, increased surgical expertise, and the use of larger femoral head diameters may play important roles in reducing the risk of instability. Full article

Background/Objectives: Diagnosis of periprosthetic joint infection (PJI) after total knee arthroplasty remains challenging when standard criteria are inconclusive. This study evaluated the diagnostic accuracy of synovial calprotectin and its prespecified exploratory adjunctive value to preoperative 2018 International Consensus Meeting (ICM) classification. Methods: This prospective single-center diagnostic accuracy study included 35 consecutive patients with primary or revision total knee arthroplasty who underwent synovial calprotectin testing followed by surgery for suspected PJI. Calprotectin was measured using a lateral flow assay with a prespecified threshold of ≥50 mg/L. Diagnostic performance was assessed against a multidisciplinary composite postoperative reference standard that did not incorporate calprotectin. Results: Twenty-one patients were classified as infected and 14 as non-infected. Calprotectin yielded 18 true-positive, 11 true-negative, 3 false-positive, and 3 false-negative results, corresponding to 85.7% sensitivity, 78.6% specificity, 85.7% positive predictive value, 78.6% negative predictive value, and an area under the curve of 0.83. Preoperative ICM correctly classified 26 patients, misclassified one, and left eight inconclusive. Among the inconclusive cases, calprotectin correctly classified all six non-infected patients but neither of the two infected patients. The combined strategy classified all 35 patients, correctly classifying 32 and misclassifying three. Among 10 antibiotic-exposed patients—seven infected and three non-infected—no misclassifications occurred; this finding was descriptive. Conclusions: Synovial calprotectin showed good overall diagnostic performance in this surgically managed cohort. When applied to preoperative ICM-inconclusive cases, it increased classification yield but missed both infected cases and should not be used alone to exclude PJI. Larger blinded multicenter studies are required before routine implementation. Full article

Background: Osteoarthritis (OA) is a prevalent degenerative joint disease with a complex molecular basis. This study aims to identify key molecules involved in OA pathogenesis, focusing on the role of acetylation-related gene expression. Methods: Public microarray datasets GSE82107 and GSE169077 were integrated to construct a differential expression landscape between OA patients and healthy controls. Acetylation-linked differentially expressed genes (acetylation-DEGs, ARDEGs) were extracted by intersecting DEGs with a curated set of acetyltransferases, deacetylases and acetylation substrates. A protein–protein interaction (PPI) network was built and subjected to LASSO-penalized regression to prioritise hub genes. Gene Ontology (GO), Kyoto Encyclopaedia of Genes and Genomes (KEGG) and Gene Set Variation Analysis (GSVA) were performed to characterize biological themes. Immune infiltration was quantified with CIBERSORTx and single-sample Gene Set Enrichment Analysis (ssGSEA). Single-cell RNA-seq data (GSE216651) were employed for orthogonal validation. For experimental corroboration, synovial tissue was collected from OA patients undergoing arthroplasty; mRNA and protein levels of hub genes were determined by qRT-PCR, Western blot and immunofluorescence. The destabilisation of the medial meniscus (DMM) mouse model was used for in vivo verification. Results: Twenty-one high-confidence ARDEGs were identified. Analysis of the PPI network yielded ten hub nodes, six of which (EGR1, PFKFB3, HDAC4, MMP13, PDK4 and ACADL) retained non-zero coefficients in the least absolute shrinkage and selection operator (LASSO) model. Enrichment analyses implicated these genes in embryonic development, collagen-containing extracellular matrix remodeling and PI3K–Akt signaling. Immune infiltration analysis showed potential differences in immune cell abundance between OA and healthy controls. Single-cell dataset analysis verified the expression patterns of key genes in different cell types. Concordant dysregulation of EGR1, PFKFB3, HDAC4, MMP13 and PDK4 was observed at both mRNA and protein levels in human OA synovium and DMM mouse joints. Conclusion: This comprehensive analysis identified acetylation-related genes and analyzed their potential biological roles in OA. The identified ARDEGs may provide new insights into OA diagnosis and treatment. Full article

Background and Objectives: Hallux rigidus is a degenerative condition of the first metatarsophalangeal joint that causes pain and limitation of motion. The aim of this study was to evaluate the clinical outcomes of a modified interpositional arthroplasty technique using an iliotibial band autograft fixed to the proximal phalanx in patients with advanced hallux rigidus. Materials and Methods: This prospective observational case series included 19 patients with Coughlin–Shurnas Grade III or IV hallux rigidus who underwent surgery between February 2023 and February 2025. Clinical outcomes were assessed using Visual Analog Scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS), and range-of-motion (ROM) measurements preoperatively and at postoperative 1, 6, and 12 months. Results: The mean VAS score decreased from 9.0 ± 0.82 preoperatively to 1.58 ± 0.51 at 12 months (p < 0.001). The mean AOFAS score increased from 35.1 ± 2.7 to 74.8 ± 10.9 (p = 0.001). ROM improved significantly at 1 and 6 months; however, the 12-month ROM was not significantly different from the preoperative value (36.3° ± 5.6° vs. 31.0° ± 5.5°, p = 0.082). Conclusions: Interpositional arthroplasty using an iliotibial band autograft fixed to the proximal phalanx was associated with short-term reductions in pain and improvements in functional scores. However, the early increase in range of motion was not maintained to the same extent at 12 months. Full article

Background/Objectives: Thrombocytopenia increases bleeding tendency and may complicate perioperative management in total knee arthroplasty (TKA), yet data on both in-hospital burden and post-discharge adverse events are limited. This study evaluated the association between preoperative platelet count and outcomes after primary TKA. Methods: In total, 3474 primary TKAs performed for osteoarthritis at a single institution (2008–2023) were retrospectively reviewed. Patients were classified as Normal, Mild, Moderate, or Severe by preoperative platelet count; the Severe group (N = 6) was excluded from comparative analyses and reported descriptively. Inverse probability of treatment weighting (IPTW) balanced baseline covariates. In-hospital outcomes were red blood cell (RBC) transfusion, intensive care unit (ICU) admission, and length of stay; follow-up outcomes were 30-day readmission, 1-year periprosthetic joint infection (PJI), and 1-year mortality. Results: After IPTW, the RBC transfusion rate rose with lower platelet count (Normal, 14.0%; Mild, 27.0%; Moderate, 32.5%; p < 0.001), and transfusion volume peaked in the Moderate group. ICU admission was more frequent (Moderate, 6.0%; Normal, 0.7%; Mild, 0.4%; p = 0.002), and length of stay increased with severity (p = 0.008). Readmission, 1-year PJI, and mortality were comparable across groups. In multivariable analysis, moderate thrombocytopenia was independently associated with RBC transfusion (adjusted odds ratio [aOR], 3.26; 95% confidence interval [CI], 1.51–6.59; p < 0.001) and ICU admission (aOR, 5.46; 95% CI, 1.37–17.41; p = 0.008), but not PJI or mortality. Conclusions: Preoperative thrombocytopenia—particularly in the mild-to-moderate range evaluated in this study—increased perioperative burden after TKA, with higher RBC transfusion and ICU utilization, but was not associated with a significant increase in major postoperative adverse events during 1-year follow-up. Even if not causally responsible, a low preoperative platelet count is a routinely available marker that may flag patients requiring closer perioperative attention. As the associated burden appears largely limited to the hospitalization period, such attentive in-hospital management may allow these patients to achieve favorable outcomes. Full article

Background/Objectives: First metatarsophalangeal (MTP) joint arthritis is a debilitating condition often treated with arthrodesis or joint replacement. However, the effectiveness of MTP joint replacement has not been thoroughly researched. This study aimed to evaluate functional outcomes and complication rates following first MTP joint replacement over a maximum seven-year follow-up period. Methods: A retrospective cohort study of 60 patients (68 toes) who underwent MTP joint replacement was performed. Data were extracted from medical records and anonymised prior to analysis. The primary outcomes measured included functional improvement and pain relief (AOFAS). Results: Findings indicate significant improvement in mean active and passive range of motion (ROM), with a mean active ROM of 35 degrees and a mean passive ROM of 45 degrees from a pre-op ROM of 0–10 degrees. The overall complication rate was 20.58%, with 10 cases of persistent stiffness but no pain and four cases of continued post-operative pain that necessitated MTP arthrodesis. Patients reported a mean post-operative AOFAS Hallux MTP-IP score of 88, improving from a pre-op score of 35. Conclusions: Results suggest that first MTP joint replacement is associated with significant pain relief and functional improvement with acceptable complication rates over the study period. Full article

Background/Objectives: Chronic lymphocytic leukemia (CLL), the most common leukemia in adults, predominantly affects the aging population. With improved survival from modern targeted therapies, a growing number of CLL patients are living long enough to become candidates for quality-of-life-improving procedures such as elective total knee arthroplasty (TKA). However, the impact of CLL on postoperative outcomes remains poorly understood. Methods: A retrospective cohort analysis was performed using the TriNetX Research Network. Adult patients who underwent primary TKA were identified and divided into two cohorts. CLL and non-CLL control, and 1:1 propensity score matching was performed on demographics and comorbidities. Medical complications were assessed at 30 and 90 days, and implant-related complications at 1 and 3 years postoperatively. Relative risks (RRs) with 95% confidence intervals (CIs) were calculated. Within the CLL cohort, a Cox proportional hazards model was used to identify preoperative laboratory values, medications, and comorbid diagnoses associated with complication development. Results: After matching, 2054 patients, 1027 per cohort, were analyzed. Patients with CLL demonstrated significantly higher risks of postoperative pain at both 30 days (p < 0.001) and 90 days (p < 0.001), as well as transfusion (p = 0.035) and acute kidney injury (p = 0.036) at 90 days. At 1 year, the CLL cohort had elevated risks of periprosthetic joint infection (PJI; p = 0.015) and arthrofibrosis (p = 0.036), and these differences persisted at 3 years (PJI p = 0.033; arthrofibrosis p = 0.006). In the hazards model, preoperative hemoglobin < 8 g/dL (HR: 1.75, 95% CI: 1.27–2.41, p < 0.001), long-term anticoagulant or antiplatelet use (HR: 1.43, 95% CI: 1.13–1.80, p = 0.003), chronic kidney disease (CKD; HR: 1.28, 95% CI: 1.04–1.58, p = 0.021), and overweight/obesity (HR: 1.23, 95% CI: 1.00–1.50, p = 0.047) were independently associated with short-term complications. Chronic opioid use was found to be associated with an increased risk of long-term complications (HR: 2.80, 95% CI: 1.49–5.24, p = 0.001). Conclusions: Patients with CLL undergoing TKA had higher observed risks of both early medical and late implant-related complications. These findings may reflect the combined effects of CLL-related immune dysfunction, cytopenias, and chronic systemic inflammation, which may impair wound healing, reduce physiologic reserve, and blunt infection clearance. Identification of associated, modifiable preoperative risk factors—anemia, anticoagulant exposure, CKD, obesity, and chronic opioid use—may provide actionable targets for optimization and risk stratification. Full article

Perioperative management of antirheumatic medications in adults with rheumatoid arthritis (RA) undergoing orthopedic surgery requires balancing postoperative infection and impaired wound healing against disease flare, pain, and delayed rehabilitation. This systematic review aimed to evaluate how perioperative continuation, withholding, interruption timing, restart timing, dose modification, or exposure to antirheumatic medications relates to postoperative outcomes in adults with RA undergoing arthroplasty and non-arthroplasty orthopedic procedures. PubMed, Scopus, and the Cochrane Central Register of Controlled Trials were searched from database inception to 18 April 2026 for English-language full-text clinical studies. The primary outcomes were surgical site infection/periprosthetic joint infection, delayed wound healing, and postoperative RA flare. Secondary outcomes included reoperation, revision, readmission, mortality, venous thromboembolism, dislocation, and other procedure-specific complications. Original studies were classified as direct perioperative strategy evidence, medication-exposure evidence, or supportive clinical-context evidence. Forty-three original clinical studies were included, together with six non-original contextual sources. The evidence was predominantly observational, clinically heterogeneous, and of very low certainty. Methotrexate continuation was not associated with an evident increase in early postoperative complications, whereas direct evidence for other conventional synthetic agents was limited. Longer interruption of biologic or targeted synthetic therapy did not consistently reduce infection or wound-healing complications, while several studies associated treatment interruption with postoperative flare. Chronic baseline glucocorticoid exposure was associated with adverse outcomes but was clinically distinct from short-term perioperative administration; stress-dose supplementation was not directly evaluated. Medication decisions should therefore be individualized according to drug class, disease control, glucocorticoid burden, surgical procedure, and patient risk profile. Full article

Osteoarthritis (OA) of the knee is characterized by cartilage matrix degeneration, which eventually leads to joint dysfunction and surgical replacement. Preoperative radiography, the standard for treatment decision making, provides limited information on the extent of degeneration, emphasizing the need for quantitative intraoperative techniques. This study evaluates the potential of vibroacoustic signals generated from instrument–tissue interactions to assess cartilage degeneration severity. A total of 136 ex vivo cartilage specimens of varying degeneration severity, histologically graded using the OARSI score, were collected from 41 patients undergoing arthroplasty. The specimens were classified into three groups: healthy cartilage (OARSI $\le 2.0$), degenerated cartilage (OARSI ≥ 2.5), and subchondral bone. Vibroacoustic signals were captured during specimen palpation using a vibration measurement system affixed to a surgical probe. 26 characteristic signal features were extracted using Continuous-Wavelet Transformation, and their discriminative power was assessed using Support Vector Machine and k-Nearest-Neighbor classifiers under patient- and specimen-level grouped cross-validation with nested hyperparameter tuning. Bone was distinguished from cartilage with 84–$91\%$ recall. Healthy cartilage (OARSI $\le 2.0$) was identifiable with 74–$80\%$ sensitivity, whereas the specificity for degenerated cartilage (OARSI ≥ 2.5) remained limited (40–$57\%$), constituting the principal limitation of the approach. Interpreting the binary cartilage classification as a diagnostic test, a receiver-operating characteristic (ROC) analysis yielded an area under the curve (AUC) of up to $0.66$ ($95\%$ CI [$0.56$, $0.76$]). The study demonstrates that vibroacoustic signals from instrument–tissue interactions may provide complementary information for intraoperative cartilage evaluation and may contribute to decision making in arthroplasty, while the reliable grading of cartilage degeneration remains an open challenge. Full article

Background: Prosthetic joint infection (PJI) following total shoulder arthroplasty (TSA) is a rare but clinically relevant complication, largely attributable to the distinctive shoulder skin microbiome, predominantly composed of Cutibacterium acnes and coagulase-negative staphylococci (CoNS), which are considered low-virulence pathogens. Standard skin disinfection protocols do not completely prevent bacterial infiltration into the surgical field; therefore, the World Health Organization (WHO) recommends the use of intraoperative irrigation to reduce the risk of shoulder PJIs. Recently, the use of povidone–iodine (PVI) irrigation has been shown to significantly reduce both bacterial load and diversity after TSA; however, its activity against C. acnes remains suboptimal. Therefore, the aim of this study was to evaluate improved in vitro disinfection protocols by combining PVI and hydrogen peroxide for use as intraoperative irrigation in shoulder arthroplasty, which is characterized by a distinctive microbiome. Methods: In vitro broth dilution assays and time-kill experiments were performed to test PVI and H₂O₂, alone or in combination, against CoNS, Staphylococcus aureus, and Escherichia coli as representative aerobic bacteria, and against C. acnes as an anaerobic pathogen. Results: The results revealed that, when used alone, PVI exerted a more pronounced bactericidal effect against staphylococci, whereas H₂O₂ was more effective against C. acnes, even at a high bacterial inoculum, although at cytotoxic concentrations, particularly for PVI. Notably, when the disinfectants were used in combination, bacterial killing was achieved against all the tested pathogens, starting from short exposure times, mainly 3 min, and at low concentrations. Moreover, the antiseptics significantly reduced mature biofilm, although complete eradication was not achieved. Conclusions: A targeted irrigation protocol to prevent shoulder PJI can be achieved by combining PVI and H₂O₂ at non-toxic concentrations and for short exposure times that do not interfere with operating room costs or increase the risk of infection. Full article

Background/Objectives. Protein needs increase with aging to support muscle health. These needs are further increased in older adults undergoing surgery, particularly in procedures limiting acute post-operative activity, such as total joint arthroplasty (TJA). However, tools to efficiently characterize dietary protein intake in clinical settings have remained undeveloped. This report describes the initial development and preliminary validation of a novel protein screener (Protein Assessment Screening Tool, PAST) for community-dwelling adults and a clinical population undergoing elective total joint arthroplasty (TJA). Methods. Participants (n = 48; 33 female, 15 male) were aged 40–70 years in the community-dwelling group (n = 22) and aged 50–70 years in the elective TJA group (n = 26). Both groups completed a 3-day food record and the PAST at two timepoints. Descriptive statistics were performed on demographic data. Differences between male and female participants and between groups were determined using independent t-tests or Mann–Whitney U tests as appropriate. The screener and 3-day food records were compared to determine sensitivity, specificity, and negative and positive predictive values (NPVs and PPVs), with a threshold of ≥1.2 g/kg/day representing adequate protein intake. Results. The PAST had relatively high sensitivity (78–87%) and PPVs (68–79%) but lower and more variable specificity (25–57%) and NPVs (33–57%); however, the 95% confidence intervals indicated variability. Conclusions. These preliminary findings demonstrate the potential clinical utility of the PAST. However, additional research is required to validate this tool prior to broad implementation in clinical practice. Full article

Background/Objectives: Asymmetric acetabular liners used in Total Hip Arthroplasty (THA) are clinically successful in reducing revision associated with dislocation. The performance of an asymmetric liner is dependent on its positioning, although few studies have directly investigated the effects of variables such as cup orientation or extended rim position on outcomes such as impingement. Therefore, the aim of this study was to compare the incidence of impingement in THA with a standard and lipped liner. Methods: A THA was virtually implanted into a previously developed geometric model. Acetabular cups were placed in a range of clinically relevant orientations, and the model was moved through seven joint motions associated with dislocation-prone Activities of Daily Living (ADLs). The occurrence of implant–implant, implant–bone, and bone–bone impingement was assessed for the standard and lipped constructs across a total of 6,237 unique combinations of cup orientation and lipped liner apex rotations. Results/Conclusions: The model predicted that with both standard and lipped constructs, there were no component placement positions which avoided impingement for all ADLs. The number of impingement incidents was minimised when components were positioned at the higher end of the manufacturer’s recommendations for cup inclination and anteversion. The use of a lipped liner increased the frequency of impingement events compared with the standard construct. However, for anterior impingement leading to posterior dislocation, this increase may be minimised by rotating the lip apex to a posterior-inferior position. Anterior lip apex placement tended to minimise the increase in the less critical posterior impingement. Full article

Background and Objectives: Synovial chondromatosis is a rare benign disease characterized by chondral metaplasia of the synovial membrane and the formation of intra-articular loose bodies. Although usually benign, delayed diagnosis may lead to progressive joint damage, recurrence, and, rarely, malignant transformation. Materials and Methods: A narrative review of the literature was conducted using the PubMed/MEDLINE database, focusing on studies published between January 2010 and December 2025. Eligible studies addressed the classification, epidemiology, clinical presentation, imaging findings, histopathology, differential diagnosis, treatment, recurrence, and prognosis of synovial chondromatosis. Results: Synovial chondromatosis most commonly affects large joints. Plain radiographs may show calcified loose bodies, whereas MRI is essential for detecting early non-calcified disease and assessing synovial involvement. Treatment depends on symptoms, disease extent, joint damage, and recurrence risk. Surgical removal of loose bodies with synovectomy remains the mainstay of treatment, while arthroplasty may be considered in advanced degenerative disease. Conclusions: This review provides an updated and clinically oriented synthesis of synovial chondromatosis, emphasizing early recognition, multidisciplinary diagnostic assessment, appropriate surgical management, and vigilant follow-up. Particular attention should be paid to recurrent disease and aggressive clinical or radiological features suggestive of malignant transformation. Full article

Background/Objectives: Total ankle arthroplasty (TAA) is increasingly used to treat end-stage ankle arthritis, but comprehensive cross-registry data on revision patterns remain limited. This study describes indications, causes, and patient risk factors for revisions using three national registries. Methods: Aggregate data were extracted from the UK National Joint Registry (NJR; 22nd Annual Report 2025; n = 11,321), the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR; 2025 Ankle Supplementary Report; n = 5379), and the Swedish Ankle Registry (SwedAnkle; Annual Report 2024; n = 1852; survival estimates from a published sub-cohort, n = 1226). Metrics were compared descriptively without inferential pooling. Results: Across registries, 18,552 primary TAAs were identified. Ten-year cumulative per cent revision (CPR) was 9.54% (95% confidence interval [CI], 8.75–10.39) in the NJR, 13.5% (95% CI, 12.1–15.1) in the AOANJRR osteoarthritis sub-cohort, and approximately 26% (author-derived from Kaplan–Meier curves; see Methods) in SwedAnkle (1993 onwards implants). Aseptic loosening was the predominant cause of revision in all three registries; the rank of subsequent causes differed between registries (infection was second in the NJR and AOANJRR; in SwedAnkle, infection ranked below insert wear/breakage at 11.5%). AOANJRR Cox analysis identified younger age (hazard ratios (HRs), 2.00 for <55 vs. ≥75 years; 95% CI, 1.30–3.07; p = 0.001), earlier surgical era (HR, 1.91 for pre-2015 vs. 2015–2024; 95% CI, 1.53–2.38; p < 0.001), and obesity (HR, 1.52 for body mass index (BMI) ≥ 30; 95% CI, 1.06–2.19; p = 0.023) as significant independent predictors in AOANJRR Cox proportional hazards models (osteoarthritis sub-cohort for age, sex, BMI and ASA; all-diagnoses primary cohort for surgical era). Sex and American Society of Anesthesiologists (ASA) scores were not significant. Conclusions: Aseptic loosening was the predominant cause of revision in all three registries. The rank of subsequent causes differed: in the NJR and AOANJRR, infection was the second most frequent cause; in SwedAnkle, infection ranked below insert wear/breakage. Younger age, obesity, and earlier surgical era were independent predictors of revision in AOANJRR Cox proportional hazards models. The post-2015 era was associated with approximately 48% lower revision hazard; this association cannot be interpreted causally, as the independent contributions of implant design, surgical technique, patient selection, and other secular changes cannot be isolated from registry data. These findings may inform preoperative counselling, implant selection, and registry harmonisation efforts. Full article