JBJS Open Access最新文献

{"title":"Should We Reconstruct Coronal Plane Fractures in Multifragmentary Pertrochanteric Fractures? A Randomized Controlled Trial.","authors":"Velmurugesan Purnaganapathi Sundaram, Nagashree Vasudeva, Agraharam Devendra, Yoga Bharathi, G S Balachandran, Sivakumar Sp, Jayaramaraju Dheenadhayalan, Shanmuganathan Rajasekaran","doi":"10.2106/JBJS.OA.26.00148","DOIUrl":"10.2106/JBJS.OA.26.00148","url":null,"abstract":"<p><strong>Introduction: </strong>Coronal plane fractures are increasingly identified in multifragmentary pertrochanteric (AO Foundation/Orthopaedic Trauma Association [AO/OTA] 31-A2) fractures, yet their clinical significance is under-researched. The aim of this study was to evaluate whether wire augmentation during Proximal Femur Nail Antirotation Asia (PFNA-II) fixation improves functional outcomes-regain of abductor strength and modified Harris Hip Score (mHHS)-compared with PFNA-II alone at 18-month follow-up. The secondary outcomes such as time to union, pain scores (Visual Analog Scale [VAS]), and complications were also assessed.</p><p><strong>Methodology: </strong>In this single-center, randomized controlled trial, 142 patients of Asian race and Indian ethnicity aged older than 60 years with AO-OTA 31-A2 fractures were treated using PFNAII, with or without wire augmentation for coronal fragments. Preoperative computed tomography (CT) assessed coronal fragment size. Among them, 116 patients who completed 18-month follow-up were analyzed.</p><p><strong>Results: </strong>Modified intention-to-treat analysis was performed. At 18 months, augmentation produced greater abductor strength (Δ 8.21%, 95% confidence interval, 4.4-12.83; p < 0.001) with no significant difference in mHHS (Δ 3.31 points, -1.3-7.9; p = 0.16). In fragments >50%, wire augmentation led to a clinically relevant 10% strength gain, exceeding the minimal clinically important difference (MCID) of 8.2%. However, VAS was similar between groups. Controls showed more varus collapse, likely due to a persisting posteromedial void when the fragment is not stabilized.</p><p><strong>Conclusion: </strong>Wire augmentation improved abductor strength recovery, especially when fragment size exceeded 50%, supporting its use in such cases. However, mHHS were similar between the groups.</p><p><strong>Level of evidence: </strong>Level I Therapeutic. See Instructions for Authors for a complete description of levels of evidence.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 3","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13322473/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148369942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reframing Fixation Strategy in Total Knee Arthroplasty With Tibial Bone Density as a Central Criterion.","authors":"Yoshinori Mikashima, Ken Okazaki","doi":"10.2106/JBJS.OA.26.00087","DOIUrl":"10.2106/JBJS.OA.26.00087","url":null,"abstract":"<p><strong>Background: </strong>Cementless total knee arthroplasty (TKA) has gained renewed interest with advances in implant design, porous coatings, and surgical accuracy. However, early aseptic loosening continues to be reported, particularly in patients with reduced tibial bone mineral density (BMD). Cemented TKA also demonstrates loosening related to thin or insufficient cement mantles, especially in younger, high-body mass index, or highly active patients. Despite advances in available fixation methods, clear and reproducible criteria to guide fixation selection have yet to be established.</p><p><strong>Methods: </strong>A narrative review was conducted to summarize recent evidence regarding fixation strategy in TKA with a focus on tibial BMD. A PubMed literature search identified studies published between 2016 and 2026 using terms related to fixation methods (cementless and cemented TKA), tibial bone density, loosening mechanisms (migration, subsidence, early failure), and cementing techniques (cement mantle thickness and cement penetration). The initial search yielded 289 articles, of which 84 studies relevant to bone density, fixation stability, implant design, and loosening mechanisms were included.</p><p><strong>Results: </strong>Large database studies consistently reported higher early aseptic loosening rates in cementless TKA, particularly in patients with low tibial BMD. Radiostereometric analyses demonstrated increased migration of cementless tibial components in low-density bone. In cemented TKA, inadequate cement penetration and thin or nonuniform cement mantles were strongly associated with tibial loosening. Recent computed tomography-based techniques-including hydroxyapatite-equivalent BMD and dual-energy computed tomography volumetric BMD-show strong correlations with trabecular bone strength and provide practical thresholds for fixation selection.</p><p><strong>Conclusion: </strong>Based on the results of all the papers reviewed, tibial BMD values are important and do influence the loosening rate of tibial components. Those patients with tibial BMD values below 46.4 HA/cm³ support the use of cemented fixation, while those exceeding 78.4 HA/cm³ seem to be better candidates for cementless fixation due to limited cement penetration.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 2","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13290156/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148333511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiographic Progression of Medial Ankle Osteoarthritis: The Influence of Global Coronal Alignment in a 7-Year Longitudinal Cohort.","authors":"Jahyung Kim, Min Gyu Kyung, Nah Yon Kim, Byung Ju Cho, Kyoung Min Lee, Dong Yeon Lee","doi":"10.2106/JBJS.OA.26.00143","DOIUrl":"10.2106/JBJS.OA.26.00143","url":null,"abstract":"<p><strong>Background: </strong>The structural progression of medial ankle osteoarthritis (OA) and the contribution of global coronal limb alignment beyond local ankle deformity remain incompletely understood. Previous longitudinal studies have focused on local talar tilt with limited evaluation of global lower-limb alignment. We hypothesized that talar tilt, medial talar translation, and varus hip-knee-ankle angle (HKA) would be associated with radiographic progression in intermediate-stage medial ankle OA.</p><p><strong>Methods: </strong>In this retrospective cohort study, 100 patients with Takakura stage 2 or 3A medial ankle OA managed nonoperatively were followed for a minimum of 5 years (mean, 83.3 ± 24.6 months). Baseline weight-bearing ankle radiographs and full-length standing teleradiographs were analyzed for talar tilt angle (TTA), medial talar translation (TCM), HKA, and additional parameters. Radiographic progression was defined as an increase in Takakura stage at final follow-up. Multivariable logistic regression was used to identify factors associated with progression. Multivariable linear regression evaluated factors associated with change in medial talar translation (ΔTCM).</p><p><strong>Results: </strong>Radiographic progression occurred in 53 patients (53%). At baseline, patients with progression had greater TTA (4.4° ± 3.3° vs. 2.9° ± 2.3°, p = 0.007) and varus HKA (5.3° ± 3.3° vs. 3.0° ± 3.0°, p < 0.001) than nonprogression patients. In multivariable analysis, higher TTA (OR 1.73; 95% CI 1.25-2.38; p < 0.001), TCM (OR 1.70; 95% CI 1.23-2.34; p = 0.001), and HKA (OR 1.59; 95% CI 1.24-2.03; p < 0.001) were associated with progression. Baseline TTA and HKA were also associated with greater ΔTCM over time. The model demonstrated strong discrimination (area under the curve = 0.88).</p><p><strong>Conclusions: </strong>Baseline talar tilt, medial talar translation, and global varus limb alignment were associated with radiographic progression of intermediate-stage medial ankle OA. These findings suggest that structural deterioration may reflect the combined influence of intra-articular deformity and global alignment rather than an exclusively local process.</p><p><strong>Level of evidence: </strong>Level III (Prognostic). See Instructions for Authors for a complete description of levels of evidence.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 2","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13290186/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148333485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Total Ankle Arthroplasty: A Comparative Review of Surgical Approaches and Outcomes.","authors":"Benjamin Hershfeld, Pranav Krish, Pedro Smith, Anthony Modica, Alexandra Krez, Brandon Klein, Adam D Bitterman","doi":"10.2106/JBJS.OA.26.00019","DOIUrl":"10.2106/JBJS.OA.26.00019","url":null,"abstract":"<p><p>» Total ankle arthroplasty (TAA) has evolved from an implant-limited procedure to a technique-sensitive operation, with surgical approach selection emerging as a key determinant of soft-tissue complications, deformity correction, and alignment accuracy. » Anterior and lateral transfibular approaches offer distinct advantages and tradeoffs in visualization, angiosome preservation, deformity correction, and technical complexity, and should not be viewed as interchangeable corridors. » Anterior approaches remain the most widely used and compatible with most implant systems but carry the highest risk of wound complications, particularly in patients with compromised anterior soft tissues or vascular disease. » The lateral transfibular approach provides extensile exposure and facilitates coronal-plane deformity correction while preserving anterior skin perfusion, at the cost of added bony morbidity, increased technical demands related to fibular osteotomy and fixation, and constrained revision options because failed lateral systems often require revision through an anterior approach using alternative implants. » Optimal outcomes in TAA depend less on the chosen approach itself than on appropriate patient selection, meticulous soft-tissue management, implant-approach compatibility, and surgeon experience, emphasizing the need for individualized, strategy-driven approach selection.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 2","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13259566/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148260008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Radiography Analysis of Functional Safe Zone During Sit-to-Stand Motion After Total Hip Arthroplasty and Its Association with Preoperative Factors.","authors":"Hiroki Shimodaira, Keiji Tensho, Suguru Koyama, Daiki Kumaki, Yusuke Maezumi, Yusuke Koyama, Manabu Takei, Hiroshi Horiuchi, Jun Takahashi","doi":"10.2106/JBJS.OA.26.00085","DOIUrl":"10.2106/JBJS.OA.26.00085","url":null,"abstract":"<p><strong>Background: </strong>Functional safe zones for implant positioning in total hip arthroplasty (THA) have primarily been evaluated in static postures. However, no studies have examined sit-to-stand movements, which carry a high risk of posterior dislocation. In this study, we recorded sit-to-stand motion post-THA using a dynamic x-ray system to analyze pelvic tilt and hip flexion angles during sitting and standing, including sex differences and the influence of sitting posture, and identify preoperative factors associated with standing alignment.</p><p><strong>Methods: </strong>We retrospectively evaluated 118 patients 6 months post-THA. Sequential lateral radiographs were used to capture maximal anterior pelvic tilt during standing. The sacral slope (SS) and pelvic-femoral angle (PFA) were measured; changes from the sitting position were calculated. Sex differences and correlations with sitting posture were assessed, and regression analyses identified predictors of standing SS and PFA.</p><p><strong>Results: </strong>The mean ΔSS was 29.6° ± 8.7°, and the mean ΔPFA was 24.8° ± 8.7°. ΔSS showed no sex difference (p = 0.331), whereas ΔPFA was larger in women (25.8° ± 8.6°) than in men (20.5° ± 8.3°, p = 0.011). ΔSS correlated negatively with sitting SS (r = -0.550, <i>p</i> < 0.001), and ΔPFA correlated positively with sitting PFA (r = 0.478, <i>p</i> < 0.001). Age, preoperative hip flexion, and pelvic incidence-lumbar lordosis (PI-LL) moderately predicted standing PFA.</p><p><strong>Conclusion: </strong>During sit-to-stand motions post-THA, the pelvis tilted anteriorly by approximately 30°, and the hip flexed by approximately 25°, influenced by sex and sitting posture. Standing hip flexion was affected by age, preoperative hip flexion angle, and PI-LL.</p><p><strong>Level of evidence: </strong>Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 2","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13259556/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148259983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Custom and Off-the-Shelf Large Language Models Routinely Misinterpret Implant Technique Guides: Too Soon to Substitute Medical Device Representatives with Generative Artificial Intelligence.","authors":"Joshua J Woo, Andrew J Yang, Yash S Saboo, Andrew J Wassef, Alexandra I Stavrakis, Stefano A Bini, Alexander B Christ, Prem N Ramkumar","doi":"10.2106/JBJS.OA.26.00076","DOIUrl":"10.2106/JBJS.OA.26.00076","url":null,"abstract":"<p><strong>Background: </strong>Large language models (LLMs) are used for clinical information retrieval, yet their performance on highly domain-specific documents such as orthopaedic technique guides or instructions for use (IFU) remains poorly understood. Various financial drivers affecting the orthopaedic medical device industry have generated interest in automated perioperative support during surgery using advanced generative artificial intelligence (AI) techniques leveraging LLMs. We sought to establish whether these complex, manufacturer-specific IFUs for surgical planning and intraoperative execution were clinically amenable to substitution by custom LLM applications.</p><p><strong>Methods: </strong>We evaluated 5 LLM-based information retrieval solutions, including 4 custom retrieval-augmented generation pipelines and ChatGPT5, in their ability to extract clinically relevant information from 3 distal femoral replacement IFUs. Two fellowship-trained orthopaedic surgeons curated 28 questions spanning literal, enumerative, and reasoned query types. Answers were scored against the expert-generated ground truth using a three-tier rubric (incorrect, partially correct, fully correct).</p><p><strong>Results: </strong>All systems demonstrated low overall accuracy (<50%). A custom multimodal pipeline achieved the highest overall score (44.6%), outperforming commercial systems such as ChatGPT (29.2%). Performance varied by document and question type: literal queries were most accurately answered (up to 53.0%), while reasoned questions yielded the lowest scores across all systems (as low as 15.3%).</p><p><strong>Conclusions: </strong>Current LLM-based retrieval systems, including commercially available tools, are unreliable for extracting complex procedural information from orthopaedic implant protocols. Whether IFUs require further clarity for clinical queries or open source LLMs require enhanced image processing, medical device representatives are far from being replaced by generative AI techniques given their poor performance in safe integration with surgical workflows. Improving LLMs with enhanced image processing and domain-specific training will be necessary before considering medical device representatives' substitution.</p><p><strong>Level of evidence: </strong>Prognostic, Level IV. See Instructions for Authors for a complete description of levels of evidence.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 2","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13259562/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148260055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early Outcomes of a Hip Arthroplasty Program in Rural Ethiopia.","authors":"Gutu Daba Kumsa, Dawit Yosef Barkesa, Abduselam Muhamed Abda, Carlos Williams, Asana Bersisa Mirkena, Gavin Button","doi":"10.2106/JBJS.OA.26.00114","DOIUrl":"10.2106/JBJS.OA.26.00114","url":null,"abstract":"<p><strong>Background: </strong>Hip arthroplasty profoundly improves quality of life. This procedure is primarily performed in the developed world by specialist surgeons and staff using sophisticated implants. Only rarely, in a few large cities, is hip arthroplasty performed in Africa. The objective of this study was to assess whether a de novo hip arthroplasty program in rural Ethiopia, at Negele Arsi General Hospital, is feasible.</p><p><strong>Methods: </strong>This cohort study analyzed data from 132 hip replacements in a total of 116 patients, the number and type of complications, and change in hip disability and osteoarthritis outcome scores (HOOSs). Preoperative and postoperative HOOSs were compared for 68 surgeries using a paired t-test; 58 surgeries had only postoperative HOOS data.</p><p><strong>Results: </strong>Between September 2021 and March 2025, a total of 97 primary total hip arthroplasty (THA) and 35 hemiarthroplasty (HA) procedures were performed, 29 by an Ethiopian team alone. The mean age of THA patients was 51 years, and 26% of patients were female. The primary indication was avascular necrosis for 41% of patients and primary osteoarthritis for 38% of patients. There was a statistically significant increase in mean HOOS subscore for THA patients from 46 to 85 and in HA from 31 to 87. There was an 11.4% complication rate with 4 failed acetabular shells, 3 femoral stem fractures, 3 dislocations, 1 deep venous thrombosis, 1 death, and no infections.</p><p><strong>Conclusions: </strong>It is possible to develop a hip arthroplasty program in a rural city in a developing country with outcomes that substantially improve patient quality of life. Early results of this study are promising; however, long-term follow-up and outcomes of Ethiopian-led surgeries alone are required to fully assess program success.</p><p><strong>Level of evidence: </strong>Level III. See Instructions for Authors for a complete description of levels of evidence.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 2","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13259558/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148259991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"5-Year Results of an Implantable Shock Absorber Demonstrate Durable Outcomes in Patients with Medial Knee Osteoarthritis.","authors":"Anil Ranawat, David Flanigan, Dennis Crawford, Seth Sherman, Jacek Walawski, Urszula Zdanowicz, Mateusz Janik, Konrad Slynarski, Marcin Domzalski, Jan Victor, David Diduch, Andreas Gomoll","doi":"10.2106/JBJS.OA.25.00187","DOIUrl":"10.2106/JBJS.OA.25.00187","url":null,"abstract":"<p><strong>Background: </strong>The implantable shock absorber (ISA) addresses patients within the knee osteoarthritis treatment gap between failure of nonsurgical care and arthroplasty.</p><p><strong>Methods: </strong>This follow-up of a prospective, open-label, comparative cohort study reports effectiveness and safety outcomes at 5 years.</p><p><strong>Results: </strong>Eighty-one participants received the ISA. Participants had statistically significant improvement in Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain (mean 43.4 point improvement, p < 0.0001) and function (mean 42.1 point improvement, p < 0.0001) versus baseline, beginning 6 weeks postsurgery, and remaining statistically significant and clinically meaningful through the 5-year follow-up. The study was designed to satisfy regulatory requirements, and survival was defined, a priori, in the study protocol with US Food and Drug Administration to be freedom from conversion to arthroplasty or high tibial osteotomy. At 5 years, 73/81 (90.1%) participants reported conversion-free survival.</p><p><strong>Conclusion: </strong>ISA provided benefits that were statistically significant and clinically meaningful for at least 5 years. Based on these 5-year data of durable, conversion-free survivorship, the ISA has proven to be a treatment option for medial knee osteoarthritis patients.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 2","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13259560/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148259988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does Transitioning to Robotic-Assisted Total Knee Arthroplasty Change Surgeon Revision Risk or Failure Modes?: A Baseline Comparative Analysis Before and After Robotic Adoption.","authors":"Wayne Hoskins, Charles Gusho, Roger Bingham, Peiyao Du, Helena Oakey, Kelly G Vince, Michael McAuliffe","doi":"10.2106/JBJS.OA.26.00127","DOIUrl":"10.2106/JBJS.OA.26.00127","url":null,"abstract":"<p><strong>Background: </strong>Robotic-assisted total knee arthroplasty (RA-TKA) may disproportionately affect revision rates based on a surgeon's revision profile. This national registry study (1) stratified surgeons by pre-RA-TKA revision rates as low, medium, or high and (2) compared the change in revision rates and modes of failure within each cohort after commencing RA-TKA.</p><p><strong>Methods: </strong>All TKA procedures performed for osteoarthritis and recorded by the Australian Orthopaedic Association National Joint Replacement Registry from September 1999 to December 2023 were screened for eligibility. A total of 178 surgeons were included, performing 85,075 TKAs since commencing RA-TKA. TKA with hinged, constrained or medial pivot bearings, and American Society of Anesthesiologists (ASA) Scores 4 and 5 were excluded. Surgeons were stratified into quartiles based on their 2-year cumulative-percent-revision (CPR) rates before commencing RA-TKA into low (2-year CPR ≤1%), middle (1%-2.5%), and high revision cohorts (≥2.5%). The primary outcome was CPR with comparisons between time-matched RA-TKA and non-RA-TKA for each surgeon cohort after commencing RA-TKA. Secondary outcomes were changes in failure modes. Cox proportional hazards modelling controlled for age, sex, body mass index, ASA, patellar resurfacing, surgical year, fixation, polyethylene, and bearing type.</p><p><strong>Results: </strong>After commencing RA-TKA, there was no difference in CPR between RA-TKA and non-RA-TKA in low (hazard ratio [HR] 1.27; 95% CI 0.84-1.91; <i>p</i> = 0.26) and middle-revision rate surgeon groups (HR 0.99; 95% CI 0.83-1.19; <i>p</i> = 0.95). High-revision rate surgeons had decreased three-month CPR (HR 0.51; 95% CI 0.34-0.75; <i>p</i> < 0.001) but increased >9-month CPR (HR 2.28; 95% CI 1.74-2.98; <i>p</i> < 0.001). The mean follow-up was 2.4, 2.4 and 2.3 years, respectively, with maximum 7-year follow-up. Failure modes including infection, loosening, and instability did not change within any revision rate cohort after commencing RA-TKA (<i>p</i> > 0.05).</p><p><strong>Conclusions: </strong>At a grouped cohort level, commencing RA-TKA does not improve revision rates nor change failure modes. Surgeons with higher revision rates before commencing RA-TKA experienced further increases in revision rates.</p><p><strong>Level of evidence: </strong>Level III. See Instructions for Authors for a complete description of levels of evidence.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 2","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13259563/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148260005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Passive Laxity in Patients With Subjective Instability Following a Cruciate-Retaining Total Knee Arthroplasty: A Pilot Study.","authors":"Longfeng Rao, Nils Horn, Alexander Mattmann, Stefan Preiss, Renate List, William R Taylor, Pascal Schütz","doi":"10.2106/JBJS.OA.26.00008","DOIUrl":"10.2106/JBJS.OA.26.00008","url":null,"abstract":"<p><strong>Background: </strong>Postoperative knee instability is one of the major underlying causes of unsatisfactory outcomes after total knee arthroplasty (TKA). However, the thresholds between stable and unstable knees remain difficult to quantify, mainly using manual clinical assessment. This pilot study aimed to understand whether differences in passive knee laxity exist between self-reported stable and unstable knees after Cruciate retaining TKA.</p><p><strong>Methods: </strong>Eight self-reported unstable and 10 stable TKA knees were assessed using fluoroscopic imaging to accurately assess the passive tibiofemoral rotation under the application of internal/external torques using a rotometer. In addition, anteroposterior and varus/valgus laxity were measured using stress radiography with a modified TELOS device.</p><p><strong>Results: </strong>Our results showed that at 30° of knee flexion, the unstable TKA knees exhibited significantly higher joint rotational laxity between 0.9 and 2.7 Nm of internal rotation torque level (p < 0.001, <i>d</i> = 2.31), as well as larger tibiofemoral anteroposterior translation in the posterior Lachman test compared with the stable knees (p < 0.05, <i>d</i> = 1.14 at 50 N, p < 0.001, <i>d</i> = 1.51 at 100 N).</p><p><strong>Conclusions: </strong>Our findings demonstrate that unstable TKA knees have increased posterior anteroposterior laxity and higher rotational laxity at low internal rotation torques at 30° of knee flexion compared with stable joints. However, our findings should be interpreted as exploratory; larger, longitudinal cohorts are still needed to mitigate bias and validate the presented findings in subjects exhibiting postarthroplasty instability.</p><p><strong>Level of evidence: </strong>Level IV diagnostic.</p>","PeriodicalId":36492,"journal":{"name":"JBJS Open Access","volume":"11 2","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13259561/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148260065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}