Bone & Joint Research最新文献

Aims: Lateral unicompartmental arthroplasty (UKA-L) is a bone- and cruciate-preserving procedure in the treatment of isolated lateral compartment gonarthrosis, but relatively little is known of its associated gait characteristics and patient-reported outcomes.

Methods: A total of 20 individuals, at a mean 35 months (SD 37) post UKA-L, were measured on an instrumented treadmill. They were compared to age-, sex-, and BMI-matched healthy controls (n = 22) and individuals with unilateral total knee arthroplasty (TKA, n = 28) mean 44 months (SD 46) post-surgery (p = 0.382). Top walking speed, temporospatial parameters, and vertical ground reaction forces of gait were analyzed. Oxford Knee Scores (OKS) and EuroQol five-dimension questionnaire (EQ-5D) scores were compared.

Results: The UKA-L group walked at a mean speed of 7.0 km/hour (SD 0.6), which was 0.2 km/hour (3%) slower than the healthy control group (7.2 km/hour (SD 0.7); p = 0.681) but 26% faster than the TKA group (5.5 km/hour (SD 0.7), p < 0.001). UKA-L displayed nearer normal vertical ground reaction forces throughout the stance phase. TKA demonstrated significantly reduced maximum weight acceptance, increased mid-stance, and reduced push-off forces compared to healthy and UKA-L subjects (all p < 0.05). UKA-L recorded similar step and stride lengths to healthy controls, and were 12% and 10% longer than TKA, respectively (p < 0.05). UKA-L was associated with a mean OKS of 44 (SD 3) compared to 36 (SD 6) for TKA (p < 0.001), and mean EQ-5D of 0.90 (SD 0.09) vs 0.78 (SD 0.14) for TKA (p = 0.003).

Conclusion: UKA-L restores healthy gait characteristics at top walking speeds. Compared to TKA, faster walking speeds, nearer-normal vertical ground reaction forces, longer stride lengths, and a more consistent gait pattern demonstrate the importance of functional cruciate ligaments to gait. UKA-L is associated with high patient satisfaction and good quality of life in the treatment of isolated lateral compartment arthrosis.

Aims: The biomechanical effects of varying rotator cuff tear severities on medialized versus lateralized reverse total shoulder arthroplasty (RTSA) remain unclear. This study aimed to compare medialized and lateralized RTSA designs based on subscapularis integrity and the severity of posterosuperior cuff tears.

Methods: A total of 12 human in vivo experimental datasets were collected during external rotation (ER) from a neutral position to 45°, with the elbow fixed at 90° and the palm facing inward. These datasets were used as inputs for musculoskeletal shoulder models of both medialized and lateralized RTSA. Inverse dynamic simulations were conducted under two subscapularis conditions-repaired (all bundles intact) and torn (all bundles torn)-across three stages of posterosuperior cuff tear severity. The scapular notching-related impingement stress, joint subluxation, and muscle-tendon forces were compared between the two RTSA configurations.

Results: Subscapularis repair in lateralized RTSA led to greater reductions in impingement stress (16.7% to 26.2%; p < 0.05) and joint subluxation (27.5% to 58.9%; p < 0.001) compared to medialized RTSA (14.1% to 18.6%; p < 0.05 and 14.7% to 22.4%; p < 0.001, respectively) across all posterosuperior cuff tear conditions. Additionally, with subscapularis repair, posterior deltoid force increased more markedly with tear severity in lateralized RTSA (from 2.6% (p = 0.007) to 918.5% (p < 0.001)) than in medialized RTSA (from 4.7% to 784.5%, both p < 0.001).

Conclusion: Lateralizing RTSA and repairing the subscapularis can significantly reduce scapular notching-related impingement, improve joint stability, and support ER torque generation by increasing posterior deltoid force in patients with posterosuperior cuff tears. These findings provide critical insights for surgical planning, supporting the use of a lateralized implant and subscapularis repair to reduce the risk of scapular notching and joint subluxation while enhancing ER torque generation.

Aims: Periprosthetic joint infection (PJI) represents one of the most severe complications following joint arthroplasty, often associated with a high recurrence rate despite appropriate therapeutic interventions. The underlying mechanisms contributing to this persistent risk remain incompletely understood. We hypothesize that alterations in joint capsule vascularization and fibrotic remodelling contribute to the pathophysiology of PJI and its recurrence.

Methods: A total of 69 patients undergoing joint arthroplasty surgery were included in the study (21 controls: primary total knee arthroplasty (TKA), 22 PJI revision: explantation, and 26 PJI revision: prosthesis reimplantation after temporary arthrodesis). Each knee joint capsule specimen was analyzed using haematoxylin and eosin (HE) staining, Masson's trichrome, Sirius red staining, immunofluorescence staining, and real-time quantitative polymerase chain reaction (RT-qPCR).

Results: Mean vessel area, diameter, and perimeter were reduced in PJI specimens, despite an overall increase in the number of blood vessels. A significant reduction in smooth muscle cell (SMC) and pericyte layer thickness, along with decreased pericyte coverage of vessel walls, was observed following both explantation and reimplantation. Fibrotic remodelling, indicated by increased collagen deposition, was markedly elevated in PJI samples at both stages. Gene expression analysis revealed upregulation of PDGFB, MIG, MMP-9, and COL1A1 at explantation or reimplantation, while PDGFA and FN1 were downregulated at explantation and significantly upregulated at reimplantation. VEGFA and FGF-2 expression remained consistently suppressed.

Conclusion: PJI is associated with profound vascular remodelling and fibrotic transformation of the joint capsule, marked by aberrant angiogenesis, disrupted vessel architecture, and distinct gene expression profiles. These alterations may impair tissue perfusion, compromise immune surveillance, and hinder antibiotic delivery, thereby contributing to recurrent infection. Targeting soft-tissue vascularization and fibrosis may represent a novel therapeutic strategy to reduce PJI recurrence and enhance surgical outcomes.

Aims: Electrochemical properties of synovial fluid are variable among patients and can lead to implant corrosion, negatively impacting their longevity. The purpose of this study was to explore the relationships between electrochemical properties of synovial fluid of knee osteoarthritic (OA) patients undergoing total knee arthroplasty (TKA) and their clinical and demographic data.

Methods: Knee OA patients undergoing TKA were enrolled in this study, and samples of their synovial fluid were collected during surgery and immediately injected into a three-electrode electrochemical cell to measure their electrochemical properties, including open circuit potential, polarization resistance, and cathodic current density. Synovial fluid samples from 43 patients were collected (25 females; mean age 69.9 years (SD 7.6); mean BMI 27.6 kg/m² (SD 5.2)). Clinical evaluation of the patients was conducted preoperatively to assess the disease severity, the inflammation in the knee joint, and patient-reported outcomes. A correlation analysis was performed to study the relationship between the electrochemical parameters of the synovial fluid and demographic and clinical data of the patients.

Results: Significant correlations were found between disease severity and both the polarization resistance and the cathodic current density, between WOMAC stiffness scores and polarization resistance, and between KSS knee scores and both open circuit potential and cathodic current density. Finally, patients with a history of oxygen-reducing medical conditions had larger open circuit potential than patients without this kind of medical history.

Conclusion: For the first time, correlations between patients' characteristics clinical and an in vivo electrochemical measurement have been obtained. The results showed that patients with more severe disease and more symptoms had less corrosive synovial fluid. Moreover, this study showed lower corrosive properties of synovial fluid in patients with a history of oxygen-reducing medical conditions, highlighting the critical role of oxygen in corrosion.

Aims: Preoperative anaemia is common in patients undergoing revision total joint replacement (TJR), yet its effects on inflammatory markers for diagnosing chronic periprosthetic joint infection (PJI) are poorly understood. This study aimed to investigate how preoperative anaemia impacts inflammatory biomarkers, and to establish anaemia-adjusted diagnostic thresholds for PJI.

Methods: This retrospective cohort study was conducted at a tertiary referral centre, evaluating 886 revision arthroplasty cases (396 PJI and 490 aseptic failures) between January 2008 and October 2023. Serum biomarkers (CRP, ESR, D-dimer, fibrinogen, fibrin degradation products (FDP), procalcitonin, and interleukin-6 (IL-6)) and synovial fluid markers (white blood cell count (SF-WBC) and polymorphonuclear percentage (SF-PMN)) were analyzed. The diagnostic performance of these markers was assessed using receiver operating characteristic (ROC) curve analysis, with patients stratified by anaemia status.

Results: Preoperative anaemia was present in 55.1% (218/396) of patients with chronic PJI. In anaemic patients, serum biomarker levels were significantly higher than those of non-anaemic patients: CRP (28.35 vs 14.75 mg/l; p < 0.001), ESR (58 vs 40 mm/h; p < 0.001), D-dimer (615 vs 415 ng/ml; p < 0.001), and IL-6 (22.19 vs 10.74 pg/ml; p < 0.001). After adjusting diagnostic thresholds for anaemia, the area under the curve (AUC) for CRP improved from 0.838 to 0.927. Similar improvements were observed for ESR and IL-6. Fibrinogen and FDP demonstrated moderate diagnostic utility, while procalcitonin showed limited diagnostic value in both anaemic and non-anaemic patients.

Conclusion: Preoperative anaemia is associated with statistically significant increases in most inflammatory biomarker levels and with higher diagnostic thresholds in chronic PJI. Anaemia-adjusted cut-off values for CRP, ESR, and IL-6 may enhance diagnostic accuracy for PJI in this patient population.

Aims: Tendinopathy is a pathological condition characterized by pain and significant dysfunction, with its pathogenesis involving various factors including chronic inflammation, cellular senescence, and apoptosis. Previous research indicates that blocking CD44 signalling exacerbates apoptosis and inflammation in tendinopathic tenocytes. Furthermore, microRNA-146a (miR-146a) has been shown to counteract interleukin-1β (IL)-1β-induced senescence in these cells, and is upregulated by CD44 in knee osteoarthritis. Therefore, this study aimed to investigate the CD44-miR-146a signalling axis in regulating apoptosis in tendinopathy.

Methods: Lentiviral vectors (LVs) were used to overexpress CD44 cDNA (LVCD44) and miR-146a precursor (LVmiR-146a) in rat primary tendinopathic tenocytes and tendons. Apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining. To dissect the CD44-AKT-miR-146a signalling pathway, the PI3K/AKT inhibitor LY294002 and the CD44 antagonizing antibody OX-50 were used. In situ hybridization (ISH) and immunohistochemistry (IHC) were performed to examine the pathway's effect on Smad4 expression in tendinopathic tenocytes and tendons.

Results: Overexpression of CD44 and miR-146a in tendinopathic tenocytes resulted in significantly reduced apoptosis compared to controls. The CD44-AKT-miR-146a signalling axis was found to mitigate apoptosis in IL-1β-stimulated tenocytes and in a rat model of collagenase-induced Achilles tendinopathy, primarily by suppressing Smad4 expression.

Conclusion: This study highlights the protective role of the CD44-AKT-miR-146a axis in tendinopathy. By modulating the AKT/miR-146a/Smad4 signalling pathway, CD44 and miR-146a effectively reduce apoptosis in tendinopathic tenocytes and tendons.

Aims: The main treatment method for distal femoral fractures is open reduction and internal fixation with a lateral locking plate. However, the literature indicates that the failure rate for this method is high, the healing is slow, and the prognosis is poor. Therefore, this study aimed to solve the problems of high failure rate and poor rehabilitation.

Methods: Data from 140 patients with AO/OTA type 33 A/33 C fractures (September 2014 to December 2023) were retrospectively analyzed. After excluding 20 cases (loss to follow-up, Gustilo III fractures, polytrauma), 120 patients were categorized into three groups: locking compression plate (LCP) alone, LCP + percutaneous medial column screws (PMCS), and LCP + auxiliary inner locking plate (ALP). An A3 fracture model of the distal femur with medial bone defect was established to explore the maximum stress and maximum displacement. Biomechanical simulations were carried out under axial, torsional, and bending loads. Clinical outcomes, finite element analysis, and biomechanical tests were compared.

Results: The LCP + PMCS technique showed better therapeutic effects compared with the other two groups. There were significant differences in fracture healing time (p < 0.001), range of knee joint motion (p < 0.001), and incidence of complications (p = 0.007). The finite element analysis results showed that the maximum stress and displacement of LCP + PMCS made it the optimal method among the three groups. Biomechanical tests confirmed that LCP + PMCS had higher yield load and stiffness.

Conclusion: LCP combined with PMCS offers enhanced biomechanical stability, reduced complications, and minimally invasive advantages, making it a promising strategy for distal femoral fractures, particularly in elderly and osteoporotic patients.

Aims: Interbody fusion stabilizes the spine by promoting bony growth between vertebrae. Large animal models have physiological and biomechanical similarities to human spines that can provide safety and efficacy data before human use. Sheep models are well validated and are the model of choice to improve understanding of fusion processes by allowing post-mortem analyses of tissues unavailable in human studies. They should be consistently designed to allow appropriate translation of the results into clinical practice. This paper investigates the methodological rigour of ovine lumbar interbody fusion (LIF) studies, and proposes recommendations for researchers designing future studies.

Methods: PubMed and the Cochrane library were searched up to 20 December 2024. The search terms were 1) lumbar AND ("in vivo" OR "animal model") AND "fusion" AND (interbody OR cage OR anterior) and 2) (lumbar AND ("in vivo" OR "animal model") AND (spine OR intervertebral disc) AND (sheep OR ovine) AND fusion).

Results: A total of 323 papers were identified; 48 studies were included after rejection of non-spinal references, duplicates, and non-English-language papers. Data regarding 993 animals and 1,668 fusion levels were examined. Animal ages varied from six months to nine years. Cages were used in 88% of studies, with a wide range of sizes. The commonest assessments included radiography, histology, and mechanical testing. The in-life phase of the studies varied from one week to three years. High risk of bias was evident in all papers, especially considering 1) treatment allocation sequences, 2) housing randomization, 3) blinding of caregivers, and 4) outcome assessment randomization.

Conclusion: This review demonstrates variability in the design of ovine LIF studies, highlights features likely to limit the translatability of results into clinical practice (sheep age and interbody cage size), shows high risk of bias in the published literature, and makes recommendations for future studies.

Aims: Osteoporosis poses a substantial public health burden. The conicity index (C-index), which integrates waist circumference, weight, and height, is a validated measure of abdominal obesity. However, its association with osteoporosis and femoral bone mineral density (BMD) remains unclear.

Methods: This study analyzed data from 16,218 USA adults (aged ≥ 20 years) in the 2005 to 2020 National Health and Nutrition Examination Survey (NHANES). Associations between C-index and osteoporosis were assessed by weighted multivariable logistic regression, while associations between C-index and femoral BMD (total femur, neck, trochanter, intertrochanter) were evaluated by weighted multivariable linear regression. Potential non-linearity was explored via generalized additive models with smooth curve fitting. Threshold effect and dose-response analyses were performed, and robustness was tested by subgroup analyses.

Results: After full adjustment for confounders, participants in the highest C-index quartile (Q4) had significantly higher odds of osteoporosis than those in the lowest quartile (Q1) (OR 1.67 (95% CI 1.23 to 2.27); p = 0.001). Each one-unit increase in C-index was associated with statistically significant decreases in BMD, as follows: total femur (-0.17 g/cm²), femoral neck (-0.18 g/cm²), trochanter (-0.17 g/cm²), and intertrochanter (-0.18 g/cm²). These associations persisted in subgroup analyses. A non-linear relationship was identified between C-index and femoral BMD.

Conclusion: Elevated C-index independently predicts osteoporosis risk and femoral BMD reduction in USA adults, with critical thresholds indicating accelerated bone loss. It thus serves as a clinically actionable metric for osteoporosis risk stratification in abdominal obesity management.