JBJS

Comparative Efficacy of Surgical Versus Nonsurgical Management for Acute Achilles Tendon Rupture in a Novel Mouse Model

J Bone Joint Surg Am. 2026 Mar 12. doi: 10.2106/JBJS.25.01211. Online ahead of print.

ABSTRACT

BACKGROUND: Acute Achilles tendon rupture is a common and serious injury in sports medicine. Clinical studies demonstrate that both surgical and nonsurgical interventions can achieve satisfactory outcomes; however, considerable debate exists regarding the optimal treatment modality for this injury. Currently, most animal experimental studies on acute Achilles tendon rupture lack clinical relevance due to inadequate fixation of the ankle joint.

METHODS: This study involved 162 male C57BL/6 mice and 30 Scx-CreERT2; Rosa26-tdTomato transgenic mice. The injury+repair groups underwent Achilles tenotomy followed by Kessler suture repair, while the injury+no repair groups underwent tenotomy alone. Ankle joints were immobilized at 160° (plantar flexion) or 90° (neutral alignment). Samples were collected at 2 and 4 weeks post-injury for biomechanical, histological, and quantitative real-time PCR (qPCR) analyses, including tracing of Scx+ tendon progenitor stem cells.

RESULTS: Biomechanical analysis was performed 2 and 4 weeks post-injury. At 2 weeks, the injury+repair group immobilized at a maximum plantar flexion angle of 160° showed significantly higher failure force and stiffness compared with the injury+no repair+160° group. However, there was no significant difference between the groups at 4 weeks (p > 0.05). The failure force in each 160° group was significantly higher than in the corresponding 90° group (p < 0.0001). Histological analysis indicated better collagen fiber alignment and higher expression of collagen type I alpha 1 (COL1A1) in the injury+repair groups. qPCR revealed generally higher expression of tendon repair-related genes (Scx, Tnmd, Tgfb1) in the injury+repair groups, while inflammatory factors (Il1b, Il6) were higher in the injury+no repair+90° group. Scx+ tendon progenitor stem cell tracing showed the greatest percentage in the injury+repair+160° group.

CONCLUSIONS: Both surgical and nonsurgical treatments for acute Achilles tendon rupture achieved satisfactory tendon healing results when the ankle joint was maintained in maximum plantar flexion. However, surgical treatment yielded superior histological tendon repair.

CLINICAL RELEVANCE: The results suggest that clinical trials may show immobilization in maximum plantar flexion following surgery to be optimal for tendon healing.

PMID:41818331 | DOI:10.2106/JBJS.25.01211

Prevascularized Bone Marrow-Derived Mesenchymal Stem Cell Sheets Promote Tendon-Bone Integration in Rotator Cuff Repair

J Bone Joint Surg Am. 2026 Mar 12. doi: 10.2106/JBJS.25.01375. Online ahead of print.

ABSTRACT

BACKGROUND: Limited vascularization at the tendon-bone interface (TBI) hinders rotator cuff (RC) healing. Although cell sheet technology has shown promise for interfacial repair, prevascularization strategies remain underexplored.

METHODS: Twenty female New Zealand rabbits underwent bilateral infraspinatus tendon repair and were randomized to receive either bone marrow-derived mesenchymal stem cell (BMSC) sheets or prevascularized BMSC sheets generated by coculture with endothelial cells, implanted at the TBI. An age- and weight-matched uninjured group served as a control. Healing at 6 weeks was assessed by gross observation, histology, immunohistochemistry, gene expression, and biomechanical testing.

RESULTS: Prevascularization of the BMSC sheets enhanced TBI vascularization, indicated by greater density of α-smooth muscle actin-positive vessels (16.16 ± 2.81 versus 10.63 ± 2.79/mm2, p = 0.0079). Immunohistochemistry demonstrated greater areas positive for collagen type II alpha 1 (86.96 ± 29.95 versus 40.25 ± 11.96 μm2, p = 0.0079) and interleukin 10 (14.93 ± 4.79 versus 7.43 ± 2.48 μm2, p = 0.0159). Biomechanically, prevascularization of the sheets yielded greater ultimate failure load (156.89 ± 51.92 versus 111.67 ± 27.51 N, p = 0.0364) and stiffness (37.27 ± 12.16 versus 27.16 ± 7.33 N/mm, p = 0.0486).

CONCLUSIONS: Prevascularization of BMSC sheets was able to promote angiogenesis and improve structural and mechanical aspects of tendon-bone healing.

CLINICAL RELEVANCE: Prevascularized BMSC sheets may represent a biologic adjunct to enhance tendon-bone healing in RC repair.

PMID:41818324 | DOI:10.2106/JBJS.25.01375

Robotic-Assisted Reverse Shoulder Arthroplasty: Rationale, Potential, Challenges, and Future Directions

J Bone Joint Surg Am. 2026 Mar 4. doi: 10.2106/JBJS.25.01537. Online ahead of print.

ABSTRACT

Robotic-assisted reverse shoulder arthroplasty has recently entered early limited clinical use, with the goal of improving the execution of preoperative plans and reducing malposition outliers that increase complication rates and health-care costs. This Innovation article reviews the rationale for this technology, explores its potential impact, examines key implementation challenges, and highlights the future directions needed to determine its ultimate value.

PMID:41779866 | DOI:10.2106/JBJS.25.01537

Results of a Novel Osteotome System for Femoral Stem Extraction in Revision Total Hip Arthroplasty: Technique, Limitations, and Associated Complications

J Bone Joint Surg Am. 2026 Mar 4;108(5):363-369. doi: 10.2106/JBJS.25.00600. Epub 2025 Nov 26.

ABSTRACT

BACKGROUND: Revision total hip arthroplasty (THA) presents several unique challenges, one of which is the removal of osseointegrated uncemented femoral stems. Traditional techniques, such as extended trochanteric osteotomy, are associated with complications and patient morbidity. Recently, the advent of osteotome systems designed to facilitate femoral stem extraction has improved the capacity for complete fixation disruption without the need for osteotomy. This study describes our experience with one such novel system in a large series of revision THAs.

METHODS: Patients undergoing femoral component revision during revision THA from December 2017 to July 2024 were identified from our institutional database. We included and analyzed patients undergoing revision for any indication so long as the revised femoral component was cementless and confirmed to be osseointegrated at the time of revision surgery. Extraction was attempted with the femoral-extraction osteotome system of interest in all cases.

RESULTS: Of the 92 included cases, 65% involved single-taper wedge stems; 16%, fit-and-fill style designs; and 9%, fully hydroxyapatite (HA)-coated stems. Using the osteotome system, femoral extraction was successful (no intraoperative fracture or requirement for osteotomy) in 73% of the cases. Osteotomy was required in 10% of the cases but was not required for extraction of any single-taper wedge stem. Of those with fit-and-fill or fully HA-coated stems, 57% required osteotomy or sustained an extraction-related fracture. Extraction-related intraoperative fractures occurred in 13% of the cases.

CONCLUSIONS: In this large series of revision THAs, the use of a novel osteotome system designed for femoral component extraction led to successful extraction in 73% of the cases. The relatively low rate of osteotomy (10%) suggests that this technique is useful, but it also highlights limitations and the need for further innovation given the contemporary shift toward the use of collared, fully coated triple-tapered stems.

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

PMID:41778989 | DOI:10.2106/JBJS.25.00600

[18F]-Fluoride PET/CT Analyses of Postoperative Bone Mineralization Adjacent to Acetabular Cups in Total Hip Arthroplasty: A Randomized Clinical Trial

J Bone Joint Surg Am. 2026 Mar 3. doi: 10.2106/JBJS.25.00961. Online ahead of print.

ABSTRACT

BACKGROUND: The longevity of total hip arthroplasty (THA) largely depends on adequate bone formation around the implant. This study used [18F]-fluoride positron emission tomography combined with computed tomography (F-PET/CT) to evaluate skeletal metabolism in the bone surrounding the acetabular cup and to compare the metabolic activity in the periprosthetic regions between cups with 2 different surfaces.

METHODS: Twenty-eight Swedish patients (15 females) with a mean age of 61.3 years were randomly assigned to receive an uncemented cup with either a Trabecular Titanium (TT) surface or a hydroxyapatite (HA) coating. The acetabular bone region surrounding the cup was divided into 9 regions of interest (ROIs). All patients were assessed with use of radiographs and clinical scoring at 36 weeks of follow-up and with use of F-PET/CT at 4, 16, and 36 weeks postoperatively.

RESULTS: F-PET/CT scans demonstrated 17% higher levels of metabolic activity indicating osseointegration in the TT group compared with the HA group at 4 weeks postoperatively. Additionally, both groups had higher standardized uptake values (SUVs) compared with the healthy reference acetabulum groups at 4 and 16 weeks postoperatively.

CONCLUSIONS: A detailed analysis of bone growth on the implant surface revealed that the initial healing phase involves increased mineral accumulation for both TT and HA cups. These findings provide valuable insights into the secondary stabilization of implants, which is critical for prosthesis survival.

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

PMID:41774785 | DOI:10.2106/JBJS.25.00961

A Blinded Analysis of Quality and Fidelity in Orthopaedic Patient Education Materials Simplified by ChatGPT and Humans

J Bone Joint Surg Am. 2026 Feb 26. doi: 10.2106/JBJS.25.00982. Online ahead of print.

ABSTRACT

BACKGROUND: Orthopaedic patient education materials (PEMs) within Epic's Elsevier library often exceed the recommended sixth-grade reading level, with a mean grade of 8.6 in English and 5.8 in Spanish, risking poor patient comprehension and adherence. The present study evaluated whether artificial intelligence (AI)-based text simplification can improve readability while preserving clinical accuracy. The objectives were to use previously established readability data for English and Spanish PEMs as baselines, to assess the impact of human-based and ChatGPT-based simplification on reading grade level, and to compare the fidelity of simplified texts against standard materials.

METHODS: In March 2025, 806 orthopaedic PEM documents were simplified using standardized ChatGPT prompts. Readability was reassessed using validated English and Spanish formulas, and fidelity was evaluated in the 86 PEMs that also had human easy-to-read versions. Two blinded clinicians compared human and ChatGPT-4o outputs with the originals to identify hallucinations, omissions, and inconsistencies according to severity. Following the release of ChatGPT-5, an unblinded post hoc analysis was performed using identical criteria.

RESULTS: ChatGPT-4o-simplified PEMs showed mean reading grade levels of 6.1 in English and 3.5 in Spanish. Compared with human simplifications, ChatGPT-4o showed fewer English omissions, similar Spanish omissions, fewer inconsistencies in both languages, and comparable English hallucinations, but higher Spanish hallucinations. Compared with ChatGPT-4o, ChatGPT-5 preserved English performance and improved Spanish fidelity, reducing hallucinations to human-comparable rates.

CONCLUSIONS: AI-driven simplification can produce orthopaedic PEMs that are easier to read while maintaining acceptable fidelity. The improvements observed with ChatGPT-5 highlight its potential for clinician-supervised use in generating accessible and reliable PEMs.

CLINICAL RELEVANCE: This study is clinically relevant because orthopaedic PEMs are routinely delivered through the Epic electronic health record and directly affect patient understanding, consent, and adherence in both English and Spanish. By evaluating the readability and fidelity of AI-simplified materials across languages, this study informs safe, scalable strategies to improve patient communication in everyday orthopaedic practice.

PMID:41747019 | DOI:10.2106/JBJS.25.00982

Mild Lateral Femoral Condyle Cartilage Damage Does Not Affect the Outcomes of Medial Unicompartmental Knee Arthroplasty: A Mean 6-Year Follow-up Study

J Bone Joint Surg Am. 2026 Feb 26. doi: 10.2106/JBJS.25.01031. Online ahead of print.

ABSTRACT

BACKGROUND: The aim of this study was to ascertain whether mild cartilage damage of the lateral condyle of the femur influences the mid-term clinical outcomes of medial unicompartmental knee arthroplasty (mUKA) and exacerbates the progression of osteoarthritis in the lateral compartment.

METHODS: Patients with normal cartilage or mild cartilage damage of the lateral femoral condyle (Outerbridge grade, ≤II) who underwent mUKA between March 2016 and December 2020 were retrospectively divided into 4 groups: a normal cartilage group and a cartilage damage group that was subdivided on the basis of the damage location (weight-bearing area, posterior weight-bearing area, and medial side of the lateral condyle). Patients with postoperative overcorrection of limb alignment or preoperative lateral meniscal extrusion were excluded. Outcomes that were compared among the groups included the hip-knee-ankle angle (HKA), lateral compartment Kellgren-Lawrence (K-L) grade, Oxford Knee Score (OKS), Forgotten Joint Score (FJS), Kujala score, patient satisfaction, and complications.

RESULTS: The study included 203 knees in 177 patients (136 female patients; 177 East Asian; mean age, 68.3 ± 7.1 years) with a mean follow-up of 70.8 months (range, 48 to 106 months). The postoperative OKS, FJS, and Kujala score showed no significant differences among the groups. Mid-term full-length standing radiographs of the lower limbs were obtained for 99 of the 203 knees, with a mean follow-up of 54.1 months (range, 49 to 104 months). Of the 99 knees, 26 (26.3%) showed an increase of 1 K-L grade in the lateral compartment and 73 (73.7%) remained unchanged. Three knees (1.5%) from the normal group experienced complications, including 1 periprosthetic fracture, 1 bearing dislocation, and 1 bearing rotation, but none required conversion to TKA.

CONCLUSIONS: In patients in whom postoperative alignment is not overcorrected and preoperative lateral meniscal function is intact, mild cartilage damage (Outerbridge grade I or II) of the lateral femoral condyle does not impact the mid-term clinical outcomes of mUKA and does not exacerbate the progression of osteoarthritis in the lateral compartment.

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

PMID:41747016 | DOI:10.2106/JBJS.25.01031

Measuring Value in Orthopaedics: The U.S. and U.K. Perspectives

J Bone Joint Surg Am. 2026 Feb 25. doi: 10.2106/JBJS.25.01106. Online ahead of print.

ABSTRACT

➢ Despite substantial health-care spending, both the U.S. and U.K. lack standardized, operational definitions of value in specialty care, limiting their ability to optimize patient-centric health outcomes and appropriate selection and utilization of resources.➢ First-generation value-based specialty care models in the U.S., like the Bundled Payments for Care Improvement Initiative and Comprehensive Care for Joint Replacement, have achieved modest savings by focusing on post-acute care and procedural efficiency, without negatively impacting quality metrics. Similarly, the Getting It Right First Time initiative in the U.K. aimed to bring about higher-quality care in hospitals, at lower cost, by reducing unwanted variations in services and practices. However, there remains no true understanding of impact on value, of efficacy based on measurement of patient-centric health outcomes that matter to patients, or of whether interventions were appropriately selected in the first place.➢ A standardized value metric, specifically the incremental cost-effectiveness ratio (ICER), is critical to measuring quality in specialty care, enabling health-care systems to compare treatment options on the basis of both cost and patient-centric outcomes.➢ The ICER integrates quality-adjusted life years, cost data, and the duration of effectiveness, providing a framework for shared decision-making, care variation reduction, and more strategic site-of-service decisions.➢ Health-care systems and policymakers should adopt ICER-based frameworks to transition from volume-based incentives to value-based models that support innovation, accountability, and whole-person musculoskeletal specialty care.

PMID:41739900 | DOI:10.2106/JBJS.25.01106

Cost-Effectiveness of Surgery Versus Functional Bracing for Humeral Shaft Fractures in Adults: A Prespecified Economic Evaluation of the Finnish Shaft of the Humerus (FISH) Trial

J Bone Joint Surg Am. 2026 Feb 24. doi: 10.2106/JBJS.25.00867. Online ahead of print.

ABSTRACT

BACKGROUND: Humeral shaft fractures commonly affect working-age adults and can lead to prolonged work absence and substantial economic burden. Although surgical fixation and functional bracing offer comparable functional outcomes, their relative cost-effectiveness remains unclear.

METHODS: We conducted a prespecified economic evaluation alongside a multicenter, superiority, randomized clinical trial at 2 Finnish university hospitals between 2012 and 2018. Eighty-two adults (mean age, 48.9 years; 38 women) with displaced, closed humeral shaft fractures were randomly assigned to surgical fixation (n = 38) or functional bracing (n = 44) and followed for 2 years. The primary outcome was the incremental net monetary benefit (INMB) based on quality-adjusted life years (QALYs) measured with the 15-dimensional (15D) instrument, analyzed from both societal and health-care perspectives.

RESULTS: From a societal perspective, surgical treatment was both more effective and less costly than bracing. The mean total cost per patient was €23,680 for surgery and €30,389 for bracing, yielding an INMB of €9,423 (95% confidence interval [CI], €4,139 to €14,609). Cost-effectiveness acceptability curves showed that surgery was highly likely to be cost-effective across all willingness-to-pay thresholds up to €120,000 per QALY. The cumulative QALYs from 6 weeks to 2 years post-injury were 1.776 (95% CI, 1.725 to 1.827) for surgery and 1.705 (95% CI, 1.641 to 1.769) for bracing, corresponding to a QALY difference of 0.071 (95% CI, 0.012 to 0.130) in favor of surgery. From the health-care perspective, functional bracing was less costly (€4,904 versus €10,967) and therefore more cost-effective, with an INMB of -€4,087 (95% CI, -€5,215 to -€3,054). When considering only direct medical costs, surgery was unlikely to be cost-effective at thresholds below €80,000 per QALY, reaching a 75% probability of cost-effectiveness only at €120,000 per QALY.

CONCLUSIONS: Surgery is cost-effective when societal costs are considered. Functional bracing remains a reasonable option, particularly for patients less affected by time away from work. Shared decision-making should incorporate both economic and individual patient factors.

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

PMID:41734249 | DOI:10.2106/JBJS.25.00867

Radiographic Measurement of Psoas Muscle Width: A Simple and Reliable Screening Tool for Sarcopenia

J Bone Joint Surg Am. 2026 Feb 23. doi: 10.2106/JBJS.25.01094. Online ahead of print.

ABSTRACT

BACKGROUND: Sarcopenia, characterized by the progressive loss of skeletal muscle mass and strength, is associated with adverse outcomes, including increased postoperative complications in patients with orthopaedic conditions. Although computed tomography (CT) and magnetic resonance imaging (MRI) remain the gold-standard modalities for assessing sarcopenia, their cost, radiation exposure, and limited availability restrict widespread screening. This study investigated the potential of lumbar spine radiographs as a practical alternative for sarcopenia screening.

METHODS: We retrospectively reviewed data of patients who underwent surgery for degenerative lumbar spine diseases at our hospital's Department of Orthopedic Surgery between June 2013 and April 2024 and had both preoperative standing lumbar spine radiographs and supine CT scans. Demographic variables (age and sex) were collected. The psoas muscle width at the caudal end plate of L3 was measured on anteroposterior lumbar spine radiographs and was compared with CT-based cross-sectional psoas muscle area. Sarcopenia was defined on the basis of previously established psoas muscle index thresholds. Interobserver reliability was assessed with the intraclass correlation coefficient (ICC), and correlation analyses, multivariable regression, and receiver operating characteristic (ROC) curve analyses were performed.

RESULTS: There were 305 patients (177 male patients [58.0%], with a median age of 71.7 years; and 128 female patients [42.0%], with a median age of 69.8 years; all ethnic Japanese) included in the analysis. Of these 305 patients, 114 (37.4%) were classified as having sarcopenia (78 male patients and 36 female patients). Radiographic psoas muscle width demonstrated excellent interobserver reliability (ICC, 0.94) and strongly correlated with the CT-measured psoas muscle area (male patients, r = 0.71; female patients, r = 0.64; both p < 0.001). Multivariable analysis identified the psoas width as a significant predictor of the psoas muscle area. ROC curve analysis revealed that optimal cutoff values for sarcopenia screening were 118.8 mm (area under the curve [AUC], 0.847) for male patients and 99.9 mm (AUC, 0.777) for female patients.

CONCLUSIONS: Radiographic psoas muscle width measurement is a simple and reliable method for sarcopenia screening that may facilitate early sarcopenia identification, enabling timely interventions and improving surgical outcome predictions. Lumbar spine radiographs hold potential as a novel screening tool for sarcopenia beyond their conventional diagnostic role.

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

PMID:41730017 | DOI:10.2106/JBJS.25.01094

Pages