JBJS

Physical Activity and 4-Year Radiographic Medial Joint Space Loss in Knee Osteoarthritis: A Joint Model Analysis

J Bone Joint Surg Am. 2025 Dec 3. doi: 10.2106/JBJS.25.00656. Online ahead of print.

ABSTRACT

BACKGROUND: We examined the association between physical activity (PA) and joint space loss (JSL) over 48 months in individuals with knee osteoarthritis to assess the role of the PA level in knee osteoarthritis progression.

METHODS: We analyzed 1,806 participants from the Osteoarthritis Initiative. PA was measured with the Physical Activity Scale for the Elderly (PASE) and was categorized as low, moderate, or high. JSL was defined as a reduction in joint space width of ≥0.7 mm. Analyses were stratified by the baseline Kellgren-Lawrence (KL) grade. Cox proportional-hazards (CoxPH) and joint models assessed the association between baseline PA and changes in longitudinal PA and JSL, adjusting for covariates.

RESULTS: Over 48 months, 33.8% of the patients experienced JSL. In patients with KL grade 2, the moderate PA tertile was associated with a reduced JSL risk compared with low PA in both standard and marginal CoxPH analyses. However, in patients with KL grade 3, increasing PA in the continuous PASE modeling was associated with increased JSL risk (marginal CoxPH: hazard ratio [HR], 1.002 [95% confidence interval (CI), 1.001 to 1.004]), confirmed by joint models (HR, 1.083 [95% CI, 1.020 to 1.150]). The rate of change of PA over time did not significantly influence progression.

CONCLUSIONS: Moderate or high PA did not increase the 4-year JSL risk in patients with KL grade 2. However, higher current PA was associated with higher JSL risk in patients with KL grade 3, highlighting the need for further research on the complex impact of PA on osteoarthritis. These findings may help clinicians to identify patient subgroups who could benefit from tailored PA recommendations, informing value-based care and personalized osteoarthritis management.

LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

PMID:41337563 | DOI:10.2106/JBJS.25.00656

Bracing Outcomes and Risk of Curve Progression in Adolescents with Idiopathic Scoliosis and Autism Spectrum Disorder

J Bone Joint Surg Am. 2025 Dec 3. doi: 10.2106/JBJS.25.00668. Online ahead of print.

ABSTRACT

BACKGROUND: Whether the sensory and behavioral traits of autism spectrum disorder (ASD) affect bracing outcomes in adolescent idiopathic scoliosis (AIS) remains unclear. This study evaluated the impact of ASD on bracing success, curve progression, and patient-reported outcomes in patients with AIS.

METHODS: This retrospective study included patients 10 to 18 years of age who were treated for AIS with bracing between 2011 and 2024. A total of 58 patients with ASD were matched in a 1:2 ratio to 116 controls with use of nearest-neighbor matching based on BrAIST-Calc predicted probabilities. Exclusions included non-idiopathic scoliosis, early-onset scoliosis, kyphoscoliosis, a Risser stage of >2, pre-treatment curves of <25° or >40°, and inadequate follow-up. Progression to the surgical threshold was defined as a major curve of ≥45°. Firth logistic regression was used to model the association between ASD and progression to the surgical threshold, adjusting for residual imbalances.

RESULTS: The matched cohort (n = 174; 51% male; 40% White, 25% Hispanic, 21% Black, 10% Asian, and 5% not specified) demonstrated balanced propensity scores (SMD = 0.006). Compared with patients without ASD, those with ASD had higher rates of progression to the surgical threshold (40% versus 20%; p = 0.005), a curve progression of ≥6° (60% versus 38%; p = 0.005), noncompliance (36% versus 22%; p = 0.04), brace-related issues (22% versus 8%; p = 0.006), and surgery being recommended or performed (33% versus 13%; p = 0.002). In the multivariable analysis, ASD (odds ratio [OR], 3.12 [95% confidence interval (CI), 1.32 to 7.35]; p = 0.009), noncompliance (OR, 4.00 [95% CI, 1.65 to 9.71]; p = 0.002), and a greater initial curve magnitude (OR per degree, 1.26 [95% CI, 1.15 to 1.38]; p < 0.001) significantly increased the odds of progression to the surgical threshold. Within the ASD group, Scoliosis Research Society-22 revised (SRS-22r) self-image, management, and total scores improved significantly over time. No significant between-group differences in change scores were observed.

CONCLUSIONS: Adolescents with ASD were >3 times more likely to progress to the surgical threshold and had higher rates of noncompliance, brace-related issues, and surgery being recommended or performed. ASD may represent a risk factor for bracing failure, potentially related to sensory or behavioral intolerance. Nonetheless, 60% of patients with ASD avoided progression to the surgical threshold, and within-group improvements in SRS-22r scores were observed. These findings support bracing as a viable treatment option for patients with ASD, although it is likely best paired with individualized care and closer follow-up. Future studies should aim to improve brace tolerance and adherence in this population.

LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

PMID:41337495 | DOI:10.2106/JBJS.25.00668

Sacral Insufficiency Fractures: Pathology, Management, and Outcomes

J Bone Joint Surg Am. 2025 Dec 3;107(23):2627-2635. doi: 10.2106/JBJS.25.00482. Epub 2025 Dec 3.

ABSTRACT

➢ Sacral insufficiency fractures are associated with high morbidity and mortality rates and are becoming increasingly prevalent in elderly patients with osteoporosis.➢ Prompt identification of these injuries and appropriate treatment for stable and unstable fractures can reduce patient morbidity.➢ The treatment of sacral insufficiency fractures depends on the severity of symptoms, which, in most cases, is associated with the degree of fracture instability. Treatment options include nonoperative measures, pharmacologic therapies, procedural treatments, and operative management.➢ Sacroplasty may be an effective procedural treatment for sacral insufficiency fractures, although there has been a lack of comparative studies, and complication types and rates are concerning.➢ Percutaneous posterior pelvic ring screws demonstrate stable fixation, allowing early patient mobilization. Standard posterior pelvic ring percutaneous fixation has high screw backout rates, although new implants may mitigate these complications.➢ There have been limited comparative data on outcomes following treatment of these injuries across procedural and operative techniques.

PMID:41335115 | DOI:10.2106/JBJS.25.00482

Clinical Application of an Ultrasonic Bone Scalpel in the Treatment of Osteoid Osteoma: A Single-Center Pilot Study

J Bone Joint Surg Am. 2025 Dec 1. doi: 10.2106/JBJS.25.00572. Online ahead of print.

ABSTRACT

BACKGROUND: No previous studies have investigated the application of an ultrasonic bone scalpel (UBS) in the treatment of osteoid osteoma (OO). We aimed to evaluate the safety and effectiveness of UBS use, either as a standalone treatment or in combination with radiofrequency ablation (RFA), for managing OO.

METHODS: In this single-center study, a retrospective analysis was performed that included patients who were radiographically or histologically diagnosed with OO at Shanghai General Hospital from September 2022 to November 2023. The treatment modalities were RFA, UBS, or RFA and UBS combined. Demographic data, clinical presentation, and radiographic characteristics were collected and analyzed. Treatment failure was defined as symptom recurrence, reoperation, or the occurrence of complications.

RESULTS: A total of 77 patients (mean age, 16.12 ± 10.91 years; 70% male; 100% Han Chinese) were included. Most lesions (60%) were located in the femur, and the mean nidus diameter in the cohort was 11.58 ± 6.57 mm. Imaging classification revealed cortical (36%), subperiosteal (7%), cancellous (32%), and intra-articular (25%) types. Treatment included RFA (30%), UBS (34%), and RFA+UBS (36%). Visual analogue scale (VAS) pain scores decreased significantly from 4.55 ± 1.12 preoperatively to 0.99 ± 0.60 on postoperative day 3 and to 0.25 ± 0.52 at 1 month (p < 0.001). No major complications occurred. The treatment success rate was 97% during the 18 to 34 months of follow-up (mean, 27.32 ± 5.05 months).

CONCLUSIONS: The UBS, whether used alone or in combination with RFA, effectively improved short-term pain relief and functional recovery in patients with OO, with no major complications. Similar to RFA, UBS use appears to be a safe and reliable treatment option for OO. Because each treatment approach has its own advantages, it is recommended to select the surgical method on the basis of the lesion characteristics. This recommended treatment algorithm supports clinical decision-making and broadens minimally invasive treatment options for OO.

LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

PMID:41325452 | DOI:10.2106/JBJS.25.00572

Chemical Disinfection of an Accidentally Contaminated and Irreplaceable Inorganic Element During Orthopaedic Surgery Is a Safe Option

J Bone Joint Surg Am. 2025 Nov 19;107(22):2582-2587. doi: 10.2106/JBJS.24.01163. Epub 2025 Nov 19.

ABSTRACT

BACKGROUND: During surgical procedures, the accidental contamination of a critical instrument or implant can jeopardize the entire operation. Resterilizing the item is not always feasible and can be time-consuming. Since extending the duration of the surgery heightens the risk of postoperative complications, it is essential to balance this risk with the risk of infection from contamination. Currently, there is no simple, safe, and quickly available method to address this issue. This study explored the efficacy of using chemical disinfection to deal with this problem.

METHODS: In part 1 of the study, 3 types of discs (cobalt-chromium, titanium, and polyethylene) were contaminated with Staphylococcus epidermidis, disinfected with use of 3 different procedures (2% chlorhexidine in 70% isopropanol alcohol, 0.9% povidone-iodine in 46% isopropanol alcohol, or 70% ethanol), and analyzed for remaining bacteria. A control group without disinfection was included. In part 2, the discs were dropped on the floor of an operating room, left on the floor for 30 seconds, and then collected before undergoing the same procedure as in part 1.

RESULTS: In part 1, all 3 alcohol-based disinfection procedures showed a high efficacy, as there was no growth found on any of the discs. These results were highly significant compared with those found for the control group (p < 0.01 for all). In the control group, polyethylene had the highest mean level of contamination (157.3 colony-forming units [CFUs]) and titanium had the lowest (58.4 CFUs). Part 2 confirmed the effectiveness of alcohol-based disinfection, with no growth observed in the test cultures. In the control group, polyethylene seemed to be the most prone to contamination. However, the level of contamination was low for all materials (0 to 8 CFUs per disc).

CONCLUSIONS: In the event of accidental contamination of an essential element or implant during a surgical procedure with no possibility of replacing the element, 2 minutes of disinfection in an alcohol-based solution seems to be a safe, simple, and quick option.

CLINICAL RELEVANCE: In the event of accidental contamination of an irreplaceable inorganic element during orthopaedic surgery, we recommend soaking the element in an alcohol-based disinfectant for 2 minutes and rinsing it with saline solution.

PMID:41315044 | PMC:PMC12614374 | DOI:10.2106/JBJS.24.01163

Diagnostic Utility of a Rapid Myeloperoxidase Test in Synovial Fluid for Chronic Periprosthetic Joint Infection

J Bone Joint Surg Am. 2025 Nov 19;107(22):2574-2581. doi: 10.2106/JBJS.24.01514. Epub 2025 Nov 19.

ABSTRACT

BACKGROUND: Numerous biomarkers have been identified for the diagnosis of periprosthetic joint infection (PJI), but no single biomarker has been proven to have definitive accuracy. Alpha-defensin is an excellent biomarker that is included as a minor criterion in the 2nd International Consensus Meeting (ICM) PJI diagnostic criteria; however, its high cost limits its accessibility at many general medical facilities. Consequently, alternative biomarkers for PJI diagnosis are under investigation. Myeloperoxidase (MPO), an enzyme with microbicidal properties through the catalysis of hypochlorous acid production, has emerged as a promising alternative. MPO has previously been reported as an effective biomarker for PJI. In the present study, we conducted a rapid MPO test as a point-of-care test (POCT) and evaluated its diagnostic utility.

METHODS: Patients with a suspected infection after total joint arthroplasty were categorized into the PJI or aseptic failure groups according to the 2nd ICM PJI diagnostic criteria. MPO and alpha-defensin levels in synovial fluid that was collected during surgery were quantified using an enzyme-linked immunosorbent assay (ELISA), and their diagnostic accuracy was compared. Additionally, an MPO POCT was conducted, and its diagnostic accuracy was assessed.

RESULTS: The investigation included 23 patients with PJI and 23 with aseptic failure. All were Japanese. MPO and alpha-defensin ELISAs exhibited a strong correlation, and, at the optimal cutoff, both tests demonstrated a sensitivity of 0.957 and a specificity of 0.957. The MPO POCT produced results in just 10 minutes and achieved a sensitivity of 1.00 and a specificity of 0.913.

CONCLUSIONS: The MPO ELISA demonstrated high diagnostic accuracy for PJI, equivalent to that of the alpha-defensin test. Furthermore, the MPO POCT showed similarly high diagnostic accuracy. The MPO POCT is a promising and rapid tool for diagnosing PJI and could serve as an alternative to the alpha-defensin test.

LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

PMID:41315043 | DOI:10.2106/JBJS.24.01514

Synovial Fluid MicroRNA Biomarkers Enable Accurate Diagnosis of Hip and Knee Periprosthetic Joint Infections

J Bone Joint Surg Am. 2025 Nov 19;107(22):2561-2573. doi: 10.2106/JBJS.24.01559. Epub 2025 Nov 19.

ABSTRACT

BACKGROUND: Diagnosing hip and knee periprosthetic joint infections (PJIs) is challenging, necessitating sensitive and specific biomarkers for accurate diagnosis. Cell-free microRNAs (miRNAs) are emerging as noninvasive biomarkers. We hypothesized that hip and knee PJIs are associated with unique cell-free miRNA profiles in synovial fluid, which can be used for the diagnosis of infection.

METHODS: Synovial fluid samples from 173 Caucasian patients undergoing septic or aseptic revision total joint replacement (TJR) of the hip or knee, as well as samples from 6 osteoarthritic knees, were analyzed. The samples were divided into a discovery group (40 samples; 50% septic) and a validation cohort (133 samples; 35% septic). Small RNA next-generation sequencing (NGS) was used to screen miRNAs in the discovery samples, with reverse transcription-quantitative polymerase chain reaction (RT-qPCR) used to confirm the NGS findings and to validate results in the independent, larger cohort. Logistic regression and cross-validation were applied to assess the diagnostic power of individual and combined miRNAs.

RESULTS: NGS identified 132 miRNAs with significant differences (false discovery rate < 0.05) between the septic and aseptic synovial fluid samples. Of these, 18 miRNAs were further analyzed with use of RT-qPCR in the independent cohort, with miR-223-3p and miR-338-5p showing the highest increases in septic synovial fluid (log2 fold change >4) and miR-151a-3p and miR-214-3p showing the most substantial reductions. To investigate the performance of the multivariable models, logistic regression was performed by dividing the cohort into a training set (60%) and a test set (40%), which showed improved performance relative to that of the univariate models (median area under the curve [AUC] for the multivariable models, 0.96). A subgroup analysis by joint type, gender, and synovial fluid sample preparation confirmed robust miRNA biomarker performance for PJI.

CONCLUSIONS: Cell-free miRNA levels in the synovial fluid of patients undergoing septic hip or knee TJR were altered in response to infection, indicating immune cell activity in the joint. These miRNAs offer sensitive and specific pathogen-independent biomarkers with potential clinical applications in the diagnosis of hip and knee PJI.

LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

PMID:41315042 | PMC:PMC12614378 | DOI:10.2106/JBJS.24.01559

Timing of Debridement, Antibiotics, and Implant Retention for Early Periprosthetic Joint Infection: Data from the Finnish Arthroplasty Register

J Bone Joint Surg Am. 2025 Nov 19;107(22):2554-2560. doi: 10.2106/JBJS.25.00946. Epub 2025 Nov 19.

ABSTRACT

BACKGROUND: Debridement, antibiotics, and implant retention (DAIR) is the method of choice in the treatment of acute periprosthetic joint infection (PJI). However, the optimal timing of DAIR is somewhat unclear. We assessed the success of DAIR performed during different time intervals after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) using data from the Finnish Arthroplasty Register (FAR).

METHODS: There were 178,498 primary operations (78,888 THAs and 99,610 TKAs) from May 2014 to April 2022 recorded in the FAR. Male patients represented 53.4% of the THA group and 55.5% of the TKA group. The most common age group was ≤62 years in the THA group and ≥76 years in the TKA group. All patients were of Finnish ethnicity. A total of 1,014 DAIR procedures were performed within 6 months after the primary arthroplasty. Cases of reoperation after DAIR were followed for 1 year after the DAIR; re-revision due to PJI within 1 year was regarded as a failure of the DAIR treatment. We compared the failure rate of DAIR among 3 time intervals: 0 to 42, 43 to 84, and 85 to 180 days after the primary operation. A Cox regression model was used to assess risk factors for re-revision.

RESULTS: In the THA group, the failure rate was 15.1% when DAIR was performed within 42 days, 10.0% when performed at 43 to 84 days, and 31.4% when performed at 85 to 180 days after the primary THA. In the TKA group, the failure rate was 8.9% when DAIR was performed within 42 days, 16.7% when performed at 43 to 84 days, and 9.8% when performed at 85 to 180 days after the primary TKA. Later DAIR was not associated with an increased re-revision risk, compared with the reference of 0 to 42 days, in the THA group (43 to 84 days: hazard ratio [HR], 1.2 [95% confidence interval (CI), 0.6 to 2.2; p = 0.63]; 85 to 180 days: HR, 1.4 [95% CI, 0.6 to 3.0; p = 0.41]). The same was true in the TKA group (43 to 84 days: HR, 1.0 [95% CI, 0.4 to 2.4; p = 0.98]; 85 to 180 days: HR, 1.9 [95% CI, 1.0 to 3.8; p = 0.065]).

CONCLUSIONS: The failure rate of DAIR may not increase as much as previously thought if performed >6 weeks after primary total joint arthroplasty. Thus, DAIR can also be worth considering as a treatment method for PJI beyond the first 6 weeks postoperatively, depending on the severity of the case.

LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

PMID:41315041 | PMC:PMC12614382 | DOI:10.2106/JBJS.25.00946

Infection and Nonunion Rates in Open Fractures: Description of 6,042 Fractures from the FLOW and PREP-IT Trials

J Bone Joint Surg Am. 2025 Nov 19;107(22):2541-2553. doi: 10.2106/JBJS.24.01055. Epub 2025 Nov 19.

ABSTRACT

BACKGROUND: Infection and nonunion are common sequelae of open fractures. Studies have shown infection and nonunion rates ranging from 2% to 52% and 12% to 17%, respectively. The present article describes the rates of surgical site infection (SSI) and delayed union/nonunion following open fractures in a large contemporary series of patients from prospective clinical trials with adjudicated outcomes.

METHODS: A descriptive analysis was performed with use of patient data from the FLOW, Aqueous-PREP, and PREPARE-Open studies. These studies, published within the past 10 years, included multiple international trauma centers and shared definitions for SSI and delayed union/nonunion. SSI and delayed union/nonunion rates were stratified by the OTA/AO fracture and Gustilo-Anderson open fracture classification systems. Kaplan-Meier estimators were utilized to obtain point estimates, and the log-log transformation approach was utilized to calculate 95% confidence intervals (CIs) for outcome rates.

RESULTS: A total of 6,042 open fractures were included. The cumulative SSI rates at 12 months for Gustilo-Anderson Types 1, 2, 3A, 3B, and 3C were 5.1%, 9.7%, 13.8%, 28.9%, and 26.2%, respectively. The cumulative rates of delayed union/nonunion at 12 months for Gustilo-Anderson Types 1, 2, 3A, 3B, and 3C were 3.0%, 5.2%, 8.0%, 14.0%, and 17.0%, respectively. Utilizing the OTA/AO fracture classification to increase the point estimate granularity, the estimated 12-month SSI and delayed union/nonunion rates in 156 Gustilo-Anderson type 3B open tibial shaft fractures (OTA/AO 42) were 34.7% (95% CI, 26.7% to 41.9%) and 18.4% (95% CI, 12.0% to 24.4%), respectively. A companion website with SSI and delayed union/nonunion rates was developed to supplement this article.

CONCLUSIONS: Open fractures are a substantial problem with complications that include infection and nonunion. The present data are useful for prognosis, research study design, and informing public awareness and policy. These results show that, despite current treatment approaches, the rates of SSI and delayed union/nonunion following treatment of open fractures remain high at 1 year and are not substantially improved from historical rates spanning several decades. Although open fracture sequelae remain a burden for patients, orthopaedic surgeons, and health-care systems, there may be opportunities for improvement in outcomes.

LEVEL OF EVIDENCE: Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

PMID:41315040 | PMC:PMC12614385 | DOI:10.2106/JBJS.24.01055

Global Perspectives on the Management of Periprosthetic Joint Infection

J Bone Joint Surg Am. 2025 Nov 19;107(22):2521-2528. doi: 10.2106/JBJS.25.00775. Epub 2025 Nov 19.

ABSTRACT

➢ The rate of periprosthetic joint infection (PJI) is rising globally, with substantial regional variability, and PJI has 5-year mortality rates of 15% to 25%, which exceed those of early-stage breast and prostate cancer and rival those of colorectal and hematologic malignancies.➢ Diagnostic criteria, including synovial fluid analysis, novel culture techniques, and molecular techniques, have improved in accuracy. However, infections caused by fastidious, biofilm-forming microorganisms continue to pose a major diagnostic challenge worldwide.➢ While patient selection remains critical for successful outcomes, the use of DAIR (debridement, antibiotics, and implant retention), 1-stage, 2-stage, and 1.5-stage procedures varies across regions and is often influenced by logistical constraints, resource availability, and clinical expertise. In parallel, discordant definitions of treatment success in the literature hinder comparative research and outcome benchmarking. A tiered framework-encompassing infection eradication, surgical burden, joint function, and patient-reported outcomes-offers a path toward standardized and clinically meaningful reporting.➢ Advances in immunogenetics, artificial intelligence-driven risk modeling, and precision medicine, alongside the emergence of research consortia and global collaborations, are opening new frontiers in treatment strategies and creating opportunities for innovative, individualized approaches to PJI management.

PMID:41315038 | DOI:10.2106/JBJS.25.00775

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