Bone & Joint Research最新文献

{"title":"Kaempferol suppresses fibroblast-like synoviocyte proliferation in rheumatoid arthritis by targeting glutamate-cysteine ligase modifier subunit to inhibit ferroptosis resistance.","authors":"Yi Ling, Zehong Luo, Nina Ren, Xuemei Yuan, Feng Luo, Hui Xu, Changming Chen, Daomin Lu, Qiuyi Wang, Xueming Yao, Wukai Ma","doi":"10.1302/2046-3758.155.BJR-2025-0419.R2","DOIUrl":"https://doi.org/10.1302/2046-3758.155.BJR-2025-0419.R2","url":null,"abstract":"<p><strong>Aims: </strong>Kaempferol has demonstrated promising therapeutic potential in the treatment of rheumatoid arthritis (RA), yet its underlying mechanisms remain to be fully elucidated. This study aimed to investigate the role of kaempferol in modulating ferroptosis resistance in tumour necrosis factor-alpha (TNF-α)-induced fibroblast-like synoviocytes (RA-FLS), and to explore its molecular targets and signalling pathways involved in RA progression.</p><p><strong>Methods: </strong>Proteomic and transcriptomic analyses were employed to identify the key pathways regulated by kaempferol in TNF-α-induced RA-FLS. The effects of kaempferol on oxidative stress, ferroptosis, and cellular proliferation in RA-FLS were evaluated using flow cytometry, measurements of malondialdehyde (MDA) and superoxide dismutase (SOD) activity, FerroOrange staining, transmission electron microscopy (TEM), cell counting kit (CCK-8) assay, and 5-ethynyl-2-deoxyuridine (EdU) assay. Protein and messenger RNA (mRNA) expression levels were validated using Western blotting and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Additionally, a TNF-α-induced collagen-induced arthritis (CIA) rat model was established to examine the anti-inflammatory and antiproliferative effects of kaempferol in vivo. The functional role of the glutamate-cysteine ligase modifier (GCLM) subunit was further investigated using GCLM-overexpressing RA-FLS models.</p><p><strong>Results: </strong>Kaempferol significantly modulated oxidative phosphorylation and glutathione metabolism pathways, reducing reactive oxygen species (ROS) and lipid peroxidation levels in RA-FLS. It suppressed TNF-α-induced RA-FLS proliferation by promoting ROS accumulation and inducing ferroptosis. In the CIA model, kaempferol effectively alleviated joint swelling and reduced inflammatory cytokine levels. Mechanistically, kaempferol downregulated GCLM expression in RA-FLS, resulting in decreased p65 nuclear translocation and inhibition of nuclear factor kappa B (NF-κB) activation. This regulatory effect restored intracellular ROS, thereby overcoming ferroptosis resistance and inhibiting synoviocyte hyperproliferation.</p><p><strong>Conclusion: </strong>Kaempferol exerts anti-inflammatory and antiproliferative effects in RA by targeting the GCLM/NF-κB signalling axis. By restoring ROS and iron homeostasis and overcoming ferroptosis resistance, kaempferol inhibits RA-FLS proliferation and mitigates synovial inflammation, suggesting its potential as a novel therapeutic agent for RA treatment.</p>","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 5","pages":"482-496"},"PeriodicalIF":5.1,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147833214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Patellar thickness can critically impact knee joint biomechanics after total knee arthroplasty.","authors":"Ning Guo, Allan Maas, Thomas M Grupp, Pascal Schütz, Henning Windhagen, William R Taylor, Seyyed Hamed Hosseini Nasab","doi":"10.1302/2046-3758.155.BJR-2025-0055.R2","DOIUrl":"10.1302/2046-3758.155.BJR-2025-0055.R2","url":null,"abstract":"<p><strong>Aims: </strong>Despite the potential benefits of an increased moment arm of the knee extensor mechanism with a thicker patellar button in patients undergoing total knee arthroplasty (TKA), many surgeons are reluctant to alter the natural patellar thickness (PTh) during resurfacing. Clinically, this hesitation stems from concerns about straining the extensor apparatus under passive motion exercises and the potential consequences on postoperative joint biomechanics, but also because many patients with a thinner patella experience improved functionality, range of motion, and possibly also reduced soft-tissue pain in the short term postoperatively. However, the biomechanical relationships underlying such short- and long-term consequences remain unexplored. Our aim was to investigate the influence of PTh on knee biomechanics after TKA.</p><p><strong>Methods: </strong>This study used advanced computational modelling techniques to undertake a systematic exploration of the influence of PTh variation on knee joint kinematics, contact mechanics, and muscle and soft-tissue loading patterns during level walking and squatting.</p><p><strong>Results: </strong>Our results indicate that increased PTh efficiency enhances the extensor mechanism, which is consistent with previous studies, but our investigation additionally demonstrates the reduction in tibiofemoral loading conditions, especially at higher flexion angles. Conversely, a thinner patella induces reduced patellofemoral contact forces and pressure, and may offer increased joint range of motion.</p><p><strong>Conclusion: </strong>PTh was found to influence knee biomechanics in clinically relevant ways. A modest increase in thickness improved quadriceps efficiency and reduced tibiofemoral forces by up to ~10%, but also raised patellofemoral pressures by up to ~5 MPa. Conversely, thinner buttons lowered patellofemoral loading and may facilitate early comfort and flexion. These trade-offs were consistent across implant congruency designs, highlighting the need for patient-specific resurfacing strategies.</p>","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 5","pages":"472-481"},"PeriodicalIF":5.1,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13148873/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147833185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vivo 3D kinematic analysis of cervical facet joints under physiological loading in healthy individuals.","authors":"Yanlong Zhong, Zhihui Peng, Zhihao Zhang, Ming Chen, Jie Yang, Zizhen Zhang, Shaofeng Chen, Ke Xiao, Guoan Li, Yan Yu, Zongmiao Wan","doi":"10.1302/2046-3758.155.BJR-2025-0464.R1","DOIUrl":"10.1302/2046-3758.155.BJR-2025-0464.R1","url":null,"abstract":"<p><strong>Aims: </strong>As cervical total disc arthroplasty progresses, the biomechanics and physiology of cervical facet joints are gaining more attention. Yet, knowledge of their in vivo kinematics and synergistic functions remains limited.</p><p><strong>Methods: </strong>Approved by the ethics committee of a tertiary hospital, 20 asymptomatic adults (10 males, 10 females; mean age 34.4 years (SD 9.2)) were recruited with informed consent. Participants underwent cone-beam CT (CBCT) scans in seven functional cervical positions. 3D vertebral models were reconstructed, and local coordinate systems were established for each facet joint. Using 3D-3D registration, segmental motions and displacements were calculated in six degrees of freedom relative to the neutral position. Rotations were described as Cardan angles, and displacements as left-right, anteroposterior, and superoinferior components. Range of motion (ROM) was defined as the absolute difference between end positions and averaged across left and right facet joints.</p><p><strong>Results: </strong>In vivo analysis revealed distinct kinematic characteristics of the cervical facet joints. During flexion-extension, C0-C1 exhibited the greatest ROM (mean 25.6° (SD 5.9°)), whereas C2-C3 and C6-C7 showed relatively restricted motion. The mean total craniocervical (C0-C7) primary ROM was 62.9° (SD 7.6°), with segmental displacements mainly occurring in the anteroposterior direction, particularly at C0-C1. During axial rotation, the C1-C2 joint accounted for approximately 85% of the total motion (mean 51.4° (SD 5.1°)) and demonstrated the largest LR displacement (mean 5.2 mm (SD 4.4)). In lateral bending, the overall ROM was 35.2° (SD 7.7°), with C1-C2 again contributing the most and showing the largest LR displacement (mean 8.7 mm (SD 2.2)). These findings highlight the dominant role of C0-C1 in flexion-extension and C1-C2 in axial rotation and lateral bending, as well as the segment-specific displacement patterns of cervical facet joints.</p><p><strong>Conclusion: </strong>CBCT-based 3D-3D registration enabled precise in vivo assessment of cervical facet joint kinematics. These findings could offer valuable insights into the rehabilitation of facet joint manipulation and provide meaningful prospects for future research.</p>","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 5","pages":"461-471"},"PeriodicalIF":5.1,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13143407/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147833178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing precision in limb-salvage surgery : proof-of-concept study of an innovative multifunctional patient-specific guide.","authors":"Sam Dhaene, Milan Roelens, Léonard Geudin, Gwen Sys","doi":"10.1302/2046-3758.155.BJR-2025-0485.R1","DOIUrl":"https://doi.org/10.1302/2046-3758.155.BJR-2025-0485.R1","url":null,"abstract":"<p><strong>Aims: </strong>Achieving tumour-free margins and precise prosthetic alignment remains an important challenge in limb-salvage surgery (LSS). Malalignment can compromise limb function and implant longevity, whereas inadequate margins increase the risk of local recurrence. Therefore, this study aims to develop a novel patient-specific guide (PSG) concept that integrates both osteotomy and prosthetic alignment into a single, user-friendly platform.</p><p><strong>Methods: </strong>A multifunctional PSG was developed, composed of two primary components: a patient-specific insert that is precisely contoured to the patient's bone anatomy, and a reusable universal frame that envelops the patient-specific element. The universal frame serves as a central platform to attach auxiliary instrumentation guides that facilitate osteotomy, reaming, and prosthetic alignment. A proof-of-concept study was conducted on ten cadaveric femora. Following CT imaging, virtual preoperative planning was performed in a 3D environment. The patient-specific parts of the guide were 3D-printed based on the virtual osteotomy and prosthetic alignment planes. The guide system was sequentially applied to perform the osteotomy and prosthesis placement on each specimen. Accuracy was assessed by comparing postoperative CT scans to the preoperative virtual plans, quantifying alignment and resection errors across all planes.</p><p><strong>Results: </strong>The PSG achieved sub-degree accuracy in coronal and sagittal alignment, with median deviations of 0.4° in both planes and a median rotational deviation of 1.2° (IQR 0.2° to 2.2°). Resection height deviation was 2.4 mm (IQR 1.9 to 3.6), with 90% of cases within a 6 mm margin. No significant correlation was observed between angular and translational errors, indicating no cross-dimensional propagation of error.</p><p><strong>Conclusion: </strong>This cadaveric proof-of-concept study demonstrates that this innovative multifunctional PSG enables precise intraoperative execution of virtual preoperative plans. By integrating both resection and prosthetic alignment into a single, user-friendly, and cost-effective platform, it addresses an unmet need in limb salvage surgery and could support precision-driven standardization in oncological limb reconstruction.</p>","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 5","pages":"451-460"},"PeriodicalIF":5.1,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13138857/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147833484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A clinically applicable energy-based approach for evaluating bone strength.","authors":"Qiushi Bai, Jiahao Li, Chi Ma, Gengyu Cao, Yuanyi Wang, Da He, Sheng Lu, Qiang Yang, Yongchang Gao, Jingjing Tian, Kun Cheng, Yu Zhao","doi":"10.1302/2046-3758.155.BJR-2025-0220.R1","DOIUrl":"https://doi.org/10.1302/2046-3758.155.BJR-2025-0220.R1","url":null,"abstract":"<p><strong>Aims: </strong>Bone mineral density (BMD) is the diagnostic standard for osteoporosis but reflects only part of bone mass change. Testing bone yield strength is a better measure of biomechanical competence, yet requires destructive testing. We developed two clinically feasible approaches for assessing yield strength to improve osteoporosis identification: an intraoperative model based on surgical mechanical data, and a preoperative model using demographic and noninvasive measures.</p><p><strong>Methods: </strong>Axial force and torque during reaming/tapping were integrated to compute process energy in synthetic bone analogues (SBA). This computation was calibrated with finite element analysis (FEA) by modelling the same processes and aligning calculated and simulated energies. A relationship between destruction energy and yield strength was then derived in SBA. The protocol was applied to ex vivo human cancellous bone, where the computed energies were converted to predicted yield strength via the SBA mapping, and calibrated against paired uniaxial compression. Intraoperative mechanical data were then collected across multiple centres to estimate vertebral yield strength and to train a preoperative model from demographic and noninvasive variables.</p><p><strong>Results: </strong>Data were acquired for six SBA densities. Computed energies correlated with finite element energies (R² = 0.95), and the SBA energy to yield strength relationship showed excellent fit (R² = 0.99). In ex vivo human cancellous bone (n = 14), predicted yield strengths were corrected against uniaxial compression with high agreement (R² = 0.96) and validated in an independent sample (n = 6). Intraoperative data from 200 procedures supported a high-performing preoperative model (R² = 0.99). SHapley Additive exPlanations (SHAP) indicated positive contributions from T-score and Hounsfield units (HU) and negative contributions from BMI, female sex, and age.</p><p><strong>Conclusion: </strong>This study proposes two clinically applicable models for bone yield strength prediction, circumventing destructive testing. The preoperative model enables risk stratification, while the intraoperative model provides accurate vertebral assessment.</p>","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 5","pages":"437-450"},"PeriodicalIF":5.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13132637/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147811027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anatomy changes, signalling pathways, and clinical treatment after ankle sprain.","authors":"Junqiu Wang, Jianyao Chen, Yue Zhao, Menglang Peng, Wei Liu, Lei Zhang","doi":"10.1302/2046-3758.154.BJR-2025-0168.R1","DOIUrl":"https://doi.org/10.1302/2046-3758.154.BJR-2025-0168.R1","url":null,"abstract":"<p><strong>Aims: </strong>Ankle sprain (AS), a prevalent sports injury, often progresses to chronic ankle instability (CAI) and post-traumatic arthritis if inadequately treated. Despite known clinical manifestations, the molecular mechanisms driving poor rehabilitation outcomes remain unclear. This review aims to explore the pathological changes in anatomical structure and signalling pathways in AS, as well as the therapeutic strategies associated with these mechanisms.</p><p><strong>Methods: </strong>A comprehensive literature search was conducted in four databases: PubMed, Embase, Web of Science, and OVID MEDICINE, covering the period from January 2000 to August 2025. The search terms included combinations of \"ankle sprain,\" \"chronic ankle instability,\" \"signaling pathway,\" \"treatment\", and so on. Only articles published in English and containing relevant experimental or clinical evidence were considered. Duplication, irrelevant cases, case reports, and non-original studies were excluded.</p><p><strong>Results: </strong>This study ultimately included 20 references after screening. In AS, transforming growth factor beta-1 drives fibrosis via Smad-dependent collagen overproduction, exacerbating ligament stiffness; Piezo2 dysfunction impairs mechanosensation, contributing to proprioceptive deficits in CAI; and nuclear factor kappa B-mediated matrix metalloproteinase activation perpetuates inflammation and extracellular matrix degradation. Additionally, dysregulated apoptotic pathways further compromise ligament and cartilage integrity. Pharmacological and non-pharmacological strategies showed partial efficacy, but pathway-targeted therapies require further validation.</p><p><strong>Conclusion: </strong>Integrating biomechanical and molecular insights can optimize AS management. Future research should explore mechanoimmunomodulatory therapies to break the cycle of instability and degeneration.</p>","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 4","pages":"425-436"},"PeriodicalIF":5.1,"publicationDate":"2026-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13107349/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147762118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serological evidence linking viral infections to incident risk of hip and knee osteoarthritis.","authors":"Jialiu Fang, Zemene Demelash Kifle, Fatemeh Vazirian, Jing Tian, Silvana Bettiol, Flavia Cicuttini, Graeme Jones, Feng Pan","doi":"10.1302/2046-3758.154.BJR-2025-0299.R1","DOIUrl":"https://doi.org/10.1302/2046-3758.154.BJR-2025-0299.R1","url":null,"abstract":"<p><strong>Aims: </strong>Infections, including viral and bacterial agents, can trigger acute arthritis, with some potentially playing a role in the development of chronic arthritis such as osteoarthritis (OA). However, the role of pathogens in OA development remains unexplored. Therefore, this study aimed to investigate the associations between infectious agents and the risk of incident hip and knee OA.</p><p><strong>Methods: </strong>Data were analyzed from 7,352 UK Biobank participants (mean age 56.1 years (SD 8.2); 54.1% female), who were free of hip or knee OA at baseline. A multiplex serology panel measured serum immunoglobulin G antibody levels for 20 infectious agents, including herpesviruses, polyomaviruses, papillomaviruses, retroviruses, hepatitis viruses, bacteria, and protozoa. Incident hip and knee OA were identified through hospital and death registry records. Cox regression was used for the analyses, and the Hochberg method was used for multiple testing correction.</p><p><strong>Results: </strong>Over a median follow-up of 12.7 years (IQR 12.4 to 14.0), 262 participants developed hip and 311 developed knee OA. Seroprevalence rates for the infectious agents ranged from 0.2% to 95.5%. In fully adjusted model, seropositive agents (BK Virus (BKV) (HR 2.88; 95% CI 1.19 to 6.98), Human Papillomavirus type 18 (HPV-18) (HR 1.93; 95% CI 1.03 to 3.65), Kaposi's Sarcoma-Associated Herpesvirus (KSHV) (HR 1.50; 95% CI 1.03 to 2.20), and Merkel Cell Polyomavirus (MCV) (HR 1.40; 95% CI 1.07 to 1.85)) were associated with an increased risk of incident hip OA. Cytomegalovirus (CMV) seropositivity (HR 1.39; 95% CI 1.08 to 1.78) was associated with a higher risk of incident knee OA. BKV, MCV, and CMV remained significant after multiple testing adjustments.</p><p><strong>Conclusion: </strong>This study identified specific viral pathogens associated with an increased risk of incident hip and knee OA, with differences at the knee and hip, suggesting a potential role of preceding infections in OA pathogenesis.</p>","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 4","pages":"412-424"},"PeriodicalIF":5.1,"publicationDate":"2026-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13107217/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147760501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum.","authors":"Amy J Garner, Oliver W Dandridge, Justin P Cobb","doi":"10.1302/2046-3758.154.BJR-2026-00003","DOIUrl":"10.1302/2046-3758.154.BJR-2026-00003","url":null,"abstract":"","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 4","pages":"411"},"PeriodicalIF":5.1,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13058609/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147632408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effective therapy for periprosthetic joint infection through sequential application of non-contact low-frequency ultrasonic debridement and antiseptic solutions.","authors":"Fei Wang, Yicheng Li, Boyong Xu, Xiaogang Zhang, Wenbo Mu, Wentao Guo, Abudousaimi Aimaiti, Tuerhongjiang Wahafu, Dewen Xue, Yichang Li, Baochao Ji, Li Cao","doi":"10.1302/2046-3758.154.BJR-2025-0452.R1","DOIUrl":"10.1302/2046-3758.154.BJR-2025-0452.R1","url":null,"abstract":"<p><strong>Aims: </strong>Conventional mechanical debridement may be insufficient to fully eradicate biofilms adherent to prosthetic and surrounding tissue surfaces in cases of periprosthetic joint infection (PJI). This study aimed to evaluate the eradication efficacy and safety of non-contact low-frequency ultrasonic debridement (NLFUD) combined with antiseptic solutions against <i>Staphylococcus aureus</i> biofilms.</p><p><strong>Methods: </strong>Ex vivo, sequential NLFUD was followed by one of four antiseptic protocols (0.9% saline, 3% H₂O₂, 0.5% povidone-iodine (PI), or 3% H₂O₂ then 0.5% PI) to eliminate <i>S. aureus</i> biofilms on titanium discs, and evaluated eradication efficacy by live/dead staining and scanning electron microscopy (SEM). In vivo, the approach was subsequently evaluated in a <i>S. aureus</i>-infected PJI rat model comprising four groups: mechanical debridement alone, mechanical and chemical debridement, mechanical and NLFUD debridement, and combined mechanical, NLFUD, and chemical debridement. In vivo, biofilm disruption was assessed by SEM, and safety by haematology, hepatorenal function, major-organ histology, local angiogenic/inflammatory markers, and periprosthetic bone integration.</p><p><strong>Results: </strong>NLFUD combined with each antiseptic produced residual live and dead biofilm areas of < 1%. NLFUD + PI and NLFUD + H₂O₂ + PI groups exhibited no bacterial regrowth. SEM analysis confirmed effective biofilm disruption using NLFUD on titanium discs ex vivo and on titanium alloy prosthesis in vivo. NLFUD treatment significantly increased bacterial counts in surgical fluid (median 2,665 vs 195 CFU/ml, p = 0.002). Biofilms were reformed in all groups at two weeks after debridement surgery. No significant between-group differences were seen in local immunohistochemical markers (including periprosthetic bone integration and angiogenic markers), or systemic inflammatory indicators, and haematoxylin and eosin staining revealed no structural abnormalities in major organs.</p><p><strong>Conclusion: </strong>As an intraoperative adjunct to debridement in PJI, sequential NLFUD and antiseptic irrigation enhance immediate biofilm disruption while maintaining a favourable systemic and local safety profile, warranting clinical evaluation to reduce residual biofilm burden.</p>","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 4","pages":"397-410"},"PeriodicalIF":5.1,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13058610/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147632483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of pedicle screw transitional segment and thread distribution on postoperative rod-screw system failure : insights from clinical research and mechanical testing.","authors":"Wen Peng, Weichao Wang, Jie Zhang, Yami Liu, Peiliang Yu, Haoling Huo, Jianzeng Ren, Zhongfa Mao, Xiaojian Wang, Yiguo Yan, Cheng Wang","doi":"10.1302/2046-3758.154.BJR-2025-0215.R1","DOIUrl":"10.1302/2046-3758.154.BJR-2025-0215.R1","url":null,"abstract":"<p><strong>Aims: </strong>This study aimed to evaluate the differences in postoperative internal fixation system failure between two distinct pedicle screw designs, and to examine how variations in the transitional segment and thread distribution of these screws influence the bending mechanical properties of the rod-screw system.</p><p><strong>Methods: </strong>A retrospective analysis was performed on 81 cases of thoracolumbar posterior internal fixation surgery from January 2020 to December 2023, focusing on comparing the postoperative fracture and loosening rates associated with the two pedicle screw designs. Finite element analysis was employed to assess the impact of different transitional segment and thread distribution designs of pedicle screws on stress distribution within the rod-screw system under physiological stress conditions in a T10-L2 fracture model. Dynamic and static bending performance tests were conducted on pedicle screws and rod-screw systems featuring various transition segment and thread distribution designs.</p><p><strong>Results: </strong>The clinical analysis revealed significant variations in postoperative fracture rates among rod-screw systems with different pedicle screw designs (p < 0.05), while the rates of loosening remained largely consistent postoperatively. Finite element analysis and mechanical testing demonstrated that extending the transitional segment can mitigate the maximum stress across the entire rod-screw system and enhance the uniformity of stress distribution. This modification improves the bending performance of the pedicle screw and its rod-screw system, shifting the failure point from the pedicle screw to the connecting rod. Conversely, variations in thread distribution design exhibited minimal impact on the stress distribution and bending performance of the entire rod-screw system.</p><p><strong>Conclusion: </strong>Pedicle screws with optimally extended transitional segments can effectively alleviate local stress concentrations and enhance the bending performance of the screw and its rod-screw system, thereby reducing the risk of postoperative screw fracture.</p>","PeriodicalId":9074,"journal":{"name":"Bone & Joint Research","volume":"15 4","pages":"383-396"},"PeriodicalIF":5.1,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13055031/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147627139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}