J Bone Joint Surg Am. 2025 Aug 29. doi: 10.2106/JBJS.24.01630. Online ahead of print.

ABSTRACT

BACKGROUND: Periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) is a serious complication associated with notable loss of function, impaired quality of life, and excess short-term mortality. In this study, we aimed to report the impact of PJI on long-term mortality and its associated risk factors.

METHODS: Using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), we used Kaplan-Meier estimates of survivorship and standardized mortality ratios (SMRs) based on Australian period life tables to describe mortality rates following revision for PJI, aseptic revisions (excluding those for fracture), and unrevised primary TKA. Additionally, hazard ratios (HRs) were calculated with multivariable proportional hazard models to assess the impact of the risk factors of age, gender, comorbidities, and minor versus major revisions.

RESULTS: Among 867,113 TKA procedures overall, there were 8,642 first revisions for PJI and 25,328 aseptic first revisions. At 5, 10, and 15 years, 16.1%, 34.4%, and 53.4% of patients with revision for PJI had died. When compared with a matched population, the SMR for revision for PJI was 1.33 (95% confidence interval [CI]: 1.28 to 1.39); for aseptic revision, 0.84 (95% CI: 0.82 to 0.87); and for unrevised primary TKA, 0.79 (95% CI: 0.78 to 0.79). Increasing age and higher American Society of Anesthesiologists (ASA) scores were significant mortality risk factors. Major revisions for PJI were not associated with a greater mortality risk compared with minor revisions for PJI.

CONCLUSIONS: Patients with revision for PJI had a 33% greater-than-expected mortality. There was a high mortality in the early postoperative period, and the excess mortality risk persisted beyond 15 years. Increasing age and higher ASA scores were associated with increased mortality.

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

PMID:40880507 | DOI:10.2106/JBJS.24.01630

J Bone Joint Surg Am. 2025 Aug 29. doi: 10.2106/JBJS.24.01466. Online ahead of print.

ABSTRACT

BACKGROUND: There is no foundational classification that 3-dimensionally characterizes arthritic anatomy to preoperatively plan and postoperatively evaluate total knee arthroplasty (TKA). With the advent of computed tomography (CT) as a preoperative planning tool, the purpose of this study was to morphologically classify pre-TKA anatomy across coronal, axial, and sagittal planes to identify outlier phenotypes and establish a foundation for future philosophical, technical, and technological strategies.

METHODS: A cross-sectional analysis was conducted using 1,352 pre-TKA lower-extremity CT scans collected from a database at a single multicenter referral center. A validated deep learning and computer vision program acquired 27 lower-extremity measurements for each CT scan. An unsupervised spectral clustering algorithm morphometrically classified the cohort. The optimal number of clusters was determined through elbow-plot and eigen-gap analyses. Visualization was conducted through t-stochastic neighbor embedding, and each cluster was characterized. The analysis was repeated to assess how it was affected by severe deformity by removing impacted parameters and reassessing cluster separation.

RESULTS: Spectral clustering revealed 4 distinct pre-TKA anatomic morphologies (18.5% Type 1, 39.6% Type 2, 7.5% Type 3, 34.5% Type 4). Types 1 and 3 embodied clear outliers. Key parameters distinguishing the 4 morphologies were hip rotation, medial posterior tibial slope, hip-knee-ankle angle, tibiofemoral angle, medial proximal tibial angle, and lateral distal femoral angle. After removing variables impacted by severe deformity, the secondary analysis again demonstrated 4 distinct clusters with the same distinguishing variables.

CONCLUSIONS: CT-based phenotyping established a 3D classification of arthritic knee anatomy into 4 foundational morphologies, of which Types 1 and 3 represent outliers present in 26% of knees undergoing TKA. Unlike prior classifications emphasizing native coronal plane anatomy, 3D phenotyping of knees undergoing TKA enables recognition of outlier cases and a foundation for longitudinal evaluation in a morphologically diverse and growing surgical population. Longitudinal studies that control for implant selection, alignment technique, and applied technology are required to evaluate the impact of this classification in enabling rapid recovery and mitigating dissatisfaction after TKA.

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

PMID:40880455 | DOI:10.2106/JBJS.24.01466

J Bone Joint Surg Am. 2025 Aug 28. doi: 10.2106/JBJS.24.00733. Online ahead of print.

ABSTRACT

➢ The use of multirod constructs (≥3 rods) in complex spine surgery has increased as its utility has been recognized over the past decade.➢ There are multiple different rod configurations that may be utilized on the basis of the desired supplemental rod function, with each type having its own advantages and clinical indications.➢ Literature has continued to demonstrate a reduced incidence of pseudarthrosis, rod fracture, and reoperation when comparing multirod constructs with traditional dual-rod constructs.➢ The use of consistent nomenclature when describing multirod constructs will allow for more productive clinical and biomechanical research.

PMID:40875787 | DOI:10.2106/JBJS.24.00733

J Bone Joint Surg Am. 2025 Aug 26. doi: 10.2106/JBJS.24.01333. Online ahead of print.

ABSTRACT

➢ With any study, readers should be cautious and critical when the conclusion is that "these treatments are the same."➢ If only superiority testing was performed, failing to find a difference does not mean that the treatments are the same, even when the study was adequately powered.➢ Noninferiority analysis is the correct method to compare treatments that researchers and clinicians think may be "the same" for the primary outcome.➢ The most important aspect of a noninferiority analysis is the selection of the noninferiority margin, which is the minimum difference between groups that would be considered meaningful.➢ To perform noninferiority testing, the difference in an outcome measure of interest between experimental and control groups must be examined with respect to the noninferiority margin of the same outcome measure. Assuming that a greater value indicates improvement in an outcome measure, if the lower bound of a 95% confidence interval of a difference in means based on a 1-sided test is greater than the noninferiority margin, then the experimental treatment can be considered noninferior to the control.

PMID:40857355 | DOI:10.2106/JBJS.24.01333

J Bone Joint Surg Am. 2025 Aug 25. doi: 10.2106/JBJS.24.01326. Online ahead of print.

ABSTRACT

BACKGROUND: Fourth-generation percutaneous, or minimally invasive, hallux valgus surgery utilizes a transverse osteotomy to achieve deformity correction. There are only a small number of studies reporting the clinical and radiographic outcomes of transverse osteotomies, many of which have methodological limitations such as small sample size, limited radiographic follow-up, or use of non-validated outcome measures. The aim of this study was to provide a methodologically robust investigation of percutaneous transverse osteotomies for hallux valgus deformity.

METHODS: We studied a prospective series of consecutive patients undergoing fourth-generation metatarsal extracapsular transverse osteotomy performed by a single surgeon (P.L.) between November 2017 and January 2023. The primary outcome was clinical foot function assessed using the Manchester-Oxford Foot Questionnaire (MOXFQ), a validated patient-reported outcome measure. Secondary outcomes included the radiographic deformity (the hallux valgus angle [HVA], 1-2 intermetatarsal angle [IMA], and sesamoid position) assessed according to American Orthopaedic Foot & Ankle Society (AOFAS) guidelines as well as a visual analog scale for pain and radiographic evidence of deformity recurrence (defined as an HVA of >20° at final radiographic follow-up). P values of <0.05 were considered significant.

RESULTS: Seven hundred and twenty-nine feet (483 patients; 456 female and 27 male; mean age, 57.9 ± 11.9 years) underwent fourth-generation metatarsal extracapsular transverse osteotomy. Radiographic data were available at a vminimum of 12 months postoperatively for 99.7% of the feet, which were followed for a mean of 2.6 ± 1.3 years (range, 1.0 to 5.7 years). There was a significant improvement (p < 0.05) in both the HVA (from 29.5° ± 8.5° preoperatively to 7.3° ± 6.7° at final follow-up) and the IMA (from 12.9° ± 3.3° to 4.6° ± 2.5°). All MOXFQ domains showed significant improvement (p < 0.05), with the MOXFQ Index improving from 36.9 ± 18.9 to 13.4 ± 15.8, Pain improving from 40.5 ± 22.0 to 17.2 ± 18.3, Walking/Standing improving from 32.3 ± 23.1 to 12.0 ± 18.2, and Social Interaction improving from 40.4 ± 20.4 to 11.0 ± 15.2. The recurrence rate was 4.5% (n = 33). The complication rate was 6.1%, which included a screw removal rate of 2.9%.

CONCLUSIONS: This study, which was the largest consecutive series of any percutaneous osteotomy technique used to correct hallux valgus deformity, demonstrated significant improvement in clinical and radiographic outcomes with a low rate of recurrence.

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

PMID:40854004 | DOI:10.2106/JBJS.24.01326

J Bone Joint Surg Am. 2025 Aug 22. doi: 10.2106/JBJS.24.01236. Online ahead of print.

ABSTRACT

BACKGROUND: Tranexamic acid (TXA) and absorbable hemostat (AH) are widely used to reduce perioperative blood loss in total knee arthroplasty (TKA). However, the efficacy of single-method hemostatic strategies is increasingly insufficient for meeting clinical demands. This study tested the efficacy and safety of TXA combined with AH for perioperative blood management in TKA.

METHODS: Hemostatic efficacy was preliminarily evaluated through in vitro dynamic coagulation assays, lactate dehydrogenase activity measurements, and scanning electron microscopy, as well as in vivo using a rabbit liver bleeding model. The in vivo biocompatibility was also measured. Subsequently, the efficacy and safety of TXA combined with AH were further evaluated in a prospective, blinded study involving 149 individuals who were randomized to receive TXA, AH, or TXA+AH during TKA. The primary outcomes were perioperative blood loss, blood transfusion, hemoglobin and hematocrit levels, maximum hemoglobin change, anemia, and postoperative complications. Secondary outcomes included perioperative inflammation, coagulation function, and knee joint function.

RESULTS: Coagulation assays and the liver hemostasis model demonstrated that TXA combined with AH effectively promoted coagulation, with satisfactory biocompatibility. The clinical results of 114 Han Chinese (East Asian) patients indicated that the combination significantly reduced perioperative blood loss in TKA (564.51 ± 136.26 mL in the TXA+AH group, 879.35 ± 85.62 mL in the TXA group, and 692.70 ± 96.06 mL in the AH group; p < 0.001) without an increase in thromboembolic events or wound-related complications. Additionally, the combination accelerated early postoperative knee function recovery without significantly affecting pain scores or inflammatory markers.

CONCLUSIONS: The combination of TXA and AH effectively reduced perioperative blood loss in TKA, accelerated early patient recovery, and did not increase the rate of complications.

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

PMID:40845176 | DOI:10.2106/JBJS.24.01236

J Bone Joint Surg Am. 2025 Aug 22. doi: 10.2106/JBJS.25.00090. Online ahead of print.

ABSTRACT

BACKGROUND: Glycation stress has been implicated in frozen shoulder, potentially inducing oxidative stress through advanced glycation end products (AGEs) and their receptor (RAGE). As the role of oxidative stress in frozen shoulder remains undetermined, this study examined the expression of related genes: NOX, SOD, and PRDX.

METHODS: Thirty-eight participants 35 to 70 years old (23 men and 15 women; all ethnic Japanese) were included; 16 had frozen shoulder, and 22 had a rotator cuff tear without range-of-motion limitations. Tissue samples were collected from the rotator interval capsule and the middle glenohumeral ligament during surgical procedures. Oxidative stress was evaluated by quantifying dihydroethidium (DHE) fluorescence intensity and protein carbonyl levels. Expression levels of genes associated with oxidative stress (SOD1, SOD2, SOD3, PRDX5, NOX1, NOX4), matrix turnover and remodeling (COL1, COL3, MMP1, MMP3, MMP13), and glycation stress (RAGE, RELA) were measured using real-time polymerase chain reaction. Superoxide dismutase (SOD) activity was also evaluated.

RESULTS: In the frozen shoulder group, oxidative stress was indicated by elevated DHE fluorescence and protein carbonyl levels in tissue samples from both the rotator interval capsule and the middle glenohumeral ligament. NOX4, RELA, and MMP13 were significantly upregulated, while SOD1 was significantly downregulated, in the rotator interval capsule and middle glenohumeral ligament in the frozen shoulder group compared with the rotator cuff tear controls. PRDX5, RAGE, and COL1 were significantly upregulated and SOD2 was significantly downregulated in the rotator interval capsule in the frozen shoulder group. SOD activity was significantly downregulated in the rotator interval capsule and middle glenohumeral ligament in the frozen shoulder group.

CONCLUSIONS: The frozen shoulder group showed increased expression of glycation stress genes and NOX along with decreased SOD expression and activity, indicative of oxidative stress. Oxidative stress, in addition to glycation stress, could be involved in the pathogenesis of frozen shoulder.

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

PMID:40845125 | DOI:10.2106/JBJS.25.00090

J Bone Joint Surg Am. 2025 Aug 21. doi: 10.2106/JBJS.24.00821. Online ahead of print.

ABSTRACT

BACKGROUND: Predicting anterior cruciate ligament reconstruction (ACLR) revision risk using machine learning (ML) regression analyses of large-scale registry data offers an evidence-based approach for clinical decision-making and management at a patient-specific level. We examined the performance of an enhanced ML-Cox regression analysis of the Danish Knee Ligament Reconstruction Registry (DKRR) for predicting ACLR revision risk.

METHODS: We analyzed surgical and patient-reported outcome measure data from 18,753 patients in the DKRR who underwent primary ACLR between 2005 and 2023. Enhanced ML-Cox regression analyses, using the least absolute shrinkage and selection operator (LASSO) and stable iterative variable selection (SIVS) approaches, were applied to predict the risk of ACLR revision (i.e., the risk of repeat surgery to reconstruct the ACL). The SIVS procedure identified key variables, including age at the time of primary ACLR and several Knee injury and Osteoarthritis Outcome Score (KOOS) items from 12-month follow-up surveys, as inputs for the best-performing regression models for predicting ACLR revision risk. The resultant Cox regression models for the prediction of ACLR revision risk, therefore, did not involve an analysis of patients with incomplete 12-month follow-up survey data, including patients with graft ruptures within 12 months after the primary surgery.

RESULTS: The best-performing Cox regression model for predicting ACLR revision risk incorporated age at the time of primary ACLR and 3 KOOS items (Pain P1 and Quality of Life Q2 and Q3) from the 12-month postoperative follow-up assessment. This model demonstrated good prediction accuracy 1, 2, and 5 years after the 12-month follow-up assessment (C-index [and standard error], 0.73 [0.03], 0.73 [0.02], and 0.74 [0.02], respectively). This 4-variable Cox regression model was well-calibrated across these time points. An online clinical point-of-care tool, the Danish KOOS3 Risk Monitoring Tool (DK3), was developed for predicting ACLR revision risk.

CONCLUSIONS: Enhanced ML-Cox regression, incorporating patient age and 3 KOOS items obtained 12 months postoperatively, provided good prediction accuracy for ACLR revision risk from 1 to 5 years after the 12-month follow-up assessment, a period that has been associated with the vast majority of ACLR revisions. The newly developed DK3 point-of-care tool offers a direct-input method to predict and monitor the risk of ACLR revision.

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

PMID:40839712 | DOI:10.2106/JBJS.24.00821

J Bone Joint Surg Am. 2025 Jun 19;107(16):1818-1824. doi: 10.2106/JBJS.24.01225.

ABSTRACT

BACKGROUND: Implant-associated infections (IAIs) require aggressive debridement to eliminate microbial bioburden. The use of irrigants may improve microbial killing during debridement. This study compared the efficacy of surgical irrigants in vitro against Staphylococcus aureus alone and in combination with Candida albicans, in both planktonic and biofilm states.

METHODS: Full-strength Dakin's solution, 0.35% povidone-iodine (PI), 10% PI, 3% hydrogen peroxide (HP), a 1:1 combination of 10% PI and 3% HP (PI + HP), Irrisept, XPERIENCE, Bactisure, and normal saline solution were tested. For planktonic testing, 1 × 106 colony-forming units (CFUs) of S. aureus and C. albicans were utilized, and biofilms were grown in these conditions on 0.8 × 10-mm titanium alloy Kirschner wires for 48 hours. Killing assays were performed using 5-minute dwell times. Success was defined by complete eradication of planktonic or biofilm CFUs.

RESULTS: PI + HP and Bactisure were the only irrigants to eradicate S. aureus in both planktonic and biofilm states. PI + HP was the only irrigant to eradicate polymicrobial S. aureus + C. albicans bioburden in both states.

CONCLUSIONS: PI + HP and Bactisure were superior irrigants against S. aureus, eliminating it in planktonic and biofilm states. PI + HP was the only irrigant to eradicate polymicrobial S. aureus + C. albicans bioburden in both states. In vivo studies are needed to evaluate the clinical effectiveness.

CLINICAL RELEVANCE: Surgical irrigants have variable efficacy in eradicating microbes depending on their state of existence (planktonic versus biofilm). In this study, the most effective eradication of polymicrobial S. aureus + C. albicans bioburden was a 1:1 combination of 10% PI and 3% HP, which is of nominal cost.

PMID:40833422 | PMC:PMC12356552 | DOI:10.2106/JBJS.24.01225

J Bone Joint Surg Am. 2025 Jul 10;107(16):1879-1886. doi: 10.2106/JBJS.24.01287.

ABSTRACT

➢ Glucagon-like peptide-1 (GLP-1) receptor agonists are a promising tool for preoperative weight loss in the patient who is undergoing orthopaedic surgery and has concomitant obesity and type-2 diabetes mellitus.➢ With regard to the perioperative management of GLP-1 receptor agonists for the orthopaedic surgeon, the American Society of Anesthesiologists (ASA) recommends withholding daily-dose GLP-1 therapy on the day of the elective surgical procedure and withholding weekly-dose therapy for the week prior to the procedure.➢ The ASA recommends postponing surgery or proceeding with "full stomach precautions" if the patient undergoing an orthopaedic procedure and taking GLP-1 therapy exhibits gastrointestinal symptoms on the day of the elective procedure.➢ In the trauma setting, patients taking GLP-1 therapy should proceed with the surgical procedure at the discretion of the surgeon with full stomach precautions or a preoperative point-of-care gastric ultrasound.➢ GLP-1 receptor agonists show the potential for disease modification in osteoarthritis and osteoporosis.

PMID:40833394 | PMC:PMC12356572 | DOI:10.2106/JBJS.24.01287

J Bone Joint Surg Am. 2025 Aug 20. doi: 10.2106/JBJS.24.01411. Online ahead of print.

ABSTRACT

BACKGROUND: The effect of home call on the sleep of orthopaedic residents and attending surgeons remains unquantified, despite known negative impacts of poor sleep on cognition, fine motor skills, and decision-making. We prospectively measured the impact of home call on orthopaedic surgery residents' and attending surgeons' sleep patterns (total sleep, slow-wave sleep [SWS], and rapid eye movement [REM] sleep), as well as on heart rate variability (HRV). We hypothesized that orthopaedic home call would negatively impact all phases of sleep and suppress post-call HRV.

METHODS: Sixteen orthopaedic attending surgeons and 14 orthopaedic surgery residents taking home call at multiple Level-I trauma centers in a single program wore WHOOP 3.0 Straps. The WHOOP Strap objectively measures and quantifies total sleep, SWS, and REM sleep. Over a 13-month period, home call nights were prospectively recorded and matched with physiological data to compare on-call, post-call night 1 (PCN 1), and PCN 2 metrics. Fixed-effects regression models were used for statistical analysis.

RESULTS: Over 13 months, we observed 4,574 recorded nights of residents' sleep and 3,573 recorded nights of attending surgeons' sleep. The mean baseline (non-call night) sleep parameters were highly varied among individuals. Overall, the mean sleep time was significantly shorter (p < 0.001) for attending surgeons (6.0 hours) than for residents (6.7 hours). When on home call, residents' total sleep decreased by 20% from baseline (p < 0.001), REM sleep decreased by 12% (p < 0.001), and SWS decreased by 12% (p < 0.001). For attending surgeons, total sleep on call decreased by 10% from baseline (p < 0.001), REM sleep decreased by 7% (p < 0.001), and SWS decreased by 4% (p < 0.01).

CONCLUSIONS: Orthopaedic surgery residents and attending surgeons exhibited low baseline sleep, and taking home call reduced this further. This suggests that there is a previously unmeasured toll of home call on orthopaedic surgeons, upon which further research is required to ensure excellent patient care, maximize educational environments, and develop strategies for resilience.

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

PMID:40834105 | DOI:10.2106/JBJS.24.01411

J Bone Joint Surg Am. 2025 Aug 20;107(16):e81. doi: 10.2106/JBJS.24.01633.

NO ABSTRACT

PMID:40833424 | DOI:10.2106/JBJS.24.01633

J Bone Joint Surg Am. 2025 Aug 20;107(16):e80. doi: 10.2106/JBJS.25.00526.

NO ABSTRACT

PMID:40833398 | DOI:10.2106/JBJS.25.00526

J Bone Joint Surg Am. 2025 Aug 20;107(16):e79. doi: 10.2106/JBJS.25.00583.

NO ABSTRACT

PMID:40833396 | DOI:10.2106/JBJS.25.00583

J Bone Joint Surg Am. 2025 Jul 10;107(16):1841-1847. doi: 10.2106/JBJS.24.01304.

ABSTRACT

BACKGROUND: Researchers employ murine fracture models to study bone healing, but the temporal relationship between mouse and human fracture healing is poorly understood. The hypothesis of this study was that it was possible to quantify specific post-fracture time frames corresponding to the stages of endochondral ossification in both mice and humans.

METHODS: Radiographs of mice and human femoral fractures treated with intramedullary stabilization were reviewed. The study included 330 human femoral fractures (OTA/AO 32A, B, or C injuries) that ultimately healed without complications in patients aged 18 to 55 years and 309 surgically created midshaft femoral fractures in 3-month-old C57BL6/J mice. Multiple orthopaedic surgeons assessed the radiographs using the Modified Radiographic Union Score for Tibia (mRUST). A 4-parameter log-logistic curve was fit to describe fracture healing over time, with 3 parameters allowed to vary: Y∞ (mRUST score at time = ∞), k (healing rate in [1/log(time)]), and X0.5 (time to half-healing).

RESULTS: The values (and 95% confidence interval) for the mice were Y∞ = 14.70 (14.54 to 14.87), k = 4.54/log(days) (4.30 to 4.77), and X0.5 = 11.77 days (11.56 to 11.98). For the humans, the values were Y∞ = 16.78 (16.21 to 17.36), k = 1.37/log(days) (1.28 to 1.45), and X0.5 = 91 days (83 to 99). All parameters differed significantly between the mice and humans (p < 0.05).

CONCLUSIONS: Using mRUST scoring and mathematical modeling, we were able to quantify and compare the temporal progression of fracture healing in mice and humans.

CLINICAL RELEVANCE: These data are relevant for designing and/or interpreting fracture healing studies of mice and humans to promote rational translation of fracture research between species.

PMID:40833385 | PMC:PMC12344732 | DOI:10.2106/JBJS.24.01304

J Bone Joint Surg Am. 2025 Aug 20;107(16):e82. doi: 10.2106/JBJS.ER.23.01346.

NO ABSTRACT

PMID:40833379 | DOI:10.2106/JBJS.ER.23.01346

J Bone Joint Surg Am. 2025 Jun 4;107(16):1825-1832. doi: 10.2106/JBJS.24.00842.

ABSTRACT

BACKGROUND: Surgeons often lack objective data on patient functional outcomes, particularly as compared with the patient's baseline. The present study aimed to determine whether gait parameters recorded on Apple iPhones provided longitudinal mobility data following lower-extremity fracture surgery that matched clinical expectations. We hypothesized that iPhones would detect the mobility changes of injury and early recovery, correlate with patient-reported outcome measures, and differentiate nonunion.

METHODS: This cross-sectional study included 107 adult patients with lower-extremity fractures who owned iPhones and had at least 6 months of follow-up. Participants shared Apple Health data and completed Patient Reported Outcomes Measurement Information System (PROMIS) surveys. The primary outcome was the daily step count. Four other gait-related parameters were analyzed: walking asymmetry, double support, walking speed, and step length. Mixed-effects models compared mobility parameters at pre-injury, immediate post-injury, and 6-months post-injury time points. Correlations between mobility parameters and PROMIS surveys were assessed. A mixed-effect model evaluated the relationship between step count recovery and surgery for nonunion.

RESULTS: There was a 93% reduction in daily step count from the pre-injury period to the immediate post-injury period (95% confidence interval [CI], -94% to -93%). Other gait parameters also showed increased impairment from pre-injury to post-injury. At 6 months, step count improved sixfold relative to the immediate post-injury period but remained 52% below baseline (95% CI, -55% to -49%). PROMIS Physical Function correlated moderately with step count (r = 0.42; 95% CI, 0.25 to 0.57) and weakly with other gait parameters. Patients with a known nonunion had a 55% slower recovery of step count than those without a nonunion (95% CI: 44% to 66%).

CONCLUSIONS: Apple Health mobility parameters captured changes in mobility following lower-extremity fracture and throughout the subsequent recovery period. These metrics distinguished between patients with and without nonunions, demonstrating their potential usefulness as objective, real-world functional outcome measures. These "digital biomarkers" may aid clinical decision-making and research and could be utilized for the early identification of patients at risk for poor outcomes.

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

PMID:40833368 | PMC:PMC12354133 | DOI:10.2106/JBJS.24.00842

J Bone Joint Surg Am. 2025 Aug 20;107(16):e83. doi: 10.2106/JBJS.ER.24.00164.

NO ABSTRACT

PMID:40833364 | DOI:10.2106/JBJS.ER.24.00164

J Bone Joint Surg Am. 2025 Aug 19. doi: 10.2106/JBJS.25.00524. Online ahead of print.

NO ABSTRACT

PMID:40828958 | DOI:10.2106/JBJS.25.00524

J Bone Joint Surg Am. 2025 Aug 14. doi: 10.2106/JBJS.24.01472. Online ahead of print.

ABSTRACT

BACKGROUND: The precise pathological mechanisms through which obesity increases the risk of slipped capital femoral epiphysis (SCFE) remain unclear. We aimed to investigate the impact of childhood obesity on the morphology of the capital femoral epiphysis in children and adolescents without hip disorders.

METHODS: We performed a retrospective cross-sectional study that included 4,888 children and adolescents 7 to 19 years of age who underwent a hip or pelvic computed tomography (CT) scan, most for abdominal pain, between 2004 and 2022. Automated 3D-CT analysis assessed epiphyseal tubercle height, superior and anterior peripheral cupping, and epiphyseal tilt. Generalized additive models (GAMs) were used to examine the associations between epiphyseal morphology and age, stratified by obesity status, while adjusting for sex.

RESULTS: We observed distinct age-related trajectories of femoral-head morphology related to obesity. Subjects with obesity demonstrated a larger femoral-head diameter from ages 7 to 15 years (obese versus normal-weight differences: 0.3 to 2.3 mm), smaller epiphyseal tubercle height after 9 years of age (normal-weight versus obese differences: 0.4% to 1.3%), and a more posteriorly tilted epiphysis, as assessed by a smaller axial tilt angle (normal-weight versus obese differences: 4° to 1°) from ages 7 to 15 years. In subjects with obesity, the superior epiphyseal cupping was larger before 11 years of age (obese versus normal-weight differences: 1.6% to 0.4%), but after 13 years of age, the superior epiphyseal cupping was smaller (normal-weight versus obese differences: 0.2% to 2%).

CONCLUSIONS: Children with obesity demonstrated a smaller epiphyseal tubercle height, greater posterior epiphyseal tilt, and reduced superior cupping compared with children of normal weight. These anatomical differences may contribute to the increased risk of SCFE in patients with obesity and offer potential imaging markers for earlier identification and risk-stratification.

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

PMID:40811524 | DOI:10.2106/JBJS.24.01472