Bone & Joint Research最新文献

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.

Aims: Cartilage metabolism exhibits circadian rhythms (CR), and disruption of these often correlates with cartilage degeneration. Mechanical stimulation is a vital zeitgeber of CR in cartilage. However, the effects of mechanical loading on CR and cartilage homeostasis have not been explored. In this study, we aimed to explore the involvement of CR in mediating temporomandibular joint (TMJ) cartilage homeostasis under mechanical loading.

Methods: We introduced the mechanical loading models of both rat TMJ chondrocytes and condyle explants. The mechanical loading was applied through rhythmic compression (12 hrs on and 12 hrs off), while the mechanical unloading model was set as control through static culture of cells and explants.

Results: One-week static culture led to imbalanced cartilage metabolism and accelerated cartilage degeneration. This was accompanied by diminished levels of core clock genes (bmal1, clock, per1, and cry2), compared with oscillations of these genes in one-day static cultured chondrocytes and condyle explants. Rhythmic physiological mechanical loading for one week not only sustained the oscillations of CR genes, but also partially maintained homeostasis of cartilage. The mechanistic delineation confirmed that one week of mechanical loading promoted the nuclear-cytoplasmic shuttling of Per1 and Cry2, which were obvious in one-day static cultured chondrocytes but weakened in one-week static cultured cells. Furthermore, nuclear translocation of Cry2, but not Per1, was dependent upon mechanical loading-induced Rho-associated protein kinase (ROCK) activation and actin polymerization. Inhibition of ROCK caused actin depolymerization and partially blocked Cry2 nuclear-cytoplasmic trafficking. Finally, down-regulation of Cry2 in both chondrocytes and condyle explants attenuated mechanical loading-sustained circadian oscillations and cartilage homeostasis.

Conclusion: This study elucidated the involvement of CR in mediating mechanical loading-related cartilage homeostasis, as well as the critical role of ROCK-actin-Cry2 in regulating normal CR and homeostasis of TMJ cartilage under rhythmic mechanical loading.

Aims: The optimal treatment of proximal fifth metatarsal (MT-V) fractures remains controversial. The most commonly used classification according to Lawrence and Botte distinguishes between three fracture types (zone I to III, from proximal to distal), aiming to derive the healing potential and treatment recommendations. It has been proposed that certain fracture types, such as zone II fractures, should be allocated to zone I and therefore treated conservatively rather than surgically based on their healing potential. Accordingly, this work aims to investigate the osseous microarchitecture in the three different zones of the proximal MT-V as a morphological basis for fracture classification.

Methods: A total of 30 bilateral MT-V bones were obtained from 15 skeletally intact body donors. The zone-specific, trabecular, and cortical microarchitecture at the MT-V base was analyzed by high-resolution peripheral quantitative CT (HR-pQCT). Differences between zones I, II, and III were analyzed using group comparisons and the influence of possible demographic factors using linear regression analyses.

Results: A decrease in trabecular bone microarchitecture with a simultaneous increase in cortical parameters was observed from zones I to III. Both trabecular and cortical parameters showed greater structural similarity between zones I and II than between zones II and III. Specifically, trabecular bone mineral density, area, and bone volume fraction, as well as cortical bone mineral density and cortical thickness, all exhibited smaller mean differences between zones I and II than between zones II and III. Female sex and advanced age were risk factors for poor microarchitecture in all three zones.

Conclusion: Our observations support the assumption that, due to the closer microstructural similarity, zone II fractures might have a similarly good healing potential as zone I fractures. The observed deterioration of microarchitecture in women and the elderly might indicate an increased susceptibility to fracture in this patient group.

Aims: To assess the feasibility and reliability of shear wave elastography (SWE) as an intraoperative tool for real-time monitoring and adjustment of collateral ligament tension during total knee arthroplasty (TKA).

Methods: A total of 33 porcine knee specimens were divided into stretching (n = 13) and minimally invasive needle puncture (MNP) groups (n = 20). The stretching experiment evaluated correlations between distraction forces (20 to 60 N) and shear wave speed (SWS) in medial (MCL) and lateral collateral ligaments (LCL). The MNP experiment assessed SWS and medial gap changes during 45 punctures at 90° flexion or full extension under 45 N force. Pearson correlation, generalized linear mixed models (GLMMs), and two-way analysis of variance analyzed relationships and effects. Intra- and interobserver reliability were calculated using intraclass correlation coefficients (ICCs).

Results: In the stretching experiment, SWS increased linearly with distraction force (r = 0.67 to 0.80, p < 0.001), unaffected by ligament thickness or structure. In the MNP experiment, SWS decreased with puncture count (r = 0.73, p < 0.001), detecting tension changes earlier than medial gap measurements (5 vs 20 punctures in flexion; 10 vs 20 in extension). GLMMs confirmed significant effects of force and puncture count on SWS (p < 0.001). Reliability was excellent (ICC > 0.88).

Conclusion: SWE is a reliable, noninvasive tool for monitoring ligament tension changes during TKA, offering greater sensitivity than gap measurements. It shows great potential for optimizing knee ligament tension, improving soft-tissue balancing, and enhancing TKA outcomes.

Aims: Academic journals are essential for advancing knowledge, yet gender disparities in orthopaedic authorship persist. While most previous studies focus authorship trends on mainly North American journals, this study analyzes gender distribution among primary and senior authors, along with the geographical origins of articles, in three orthopaedic journals based in Europe and North America.

Methods: A retrospective, cross-sectional analysis was conducted on articles published from 2000 to 2004, 2010 to 2014, and 2020 to 2024 in the following journals: Acta Orthopaedica (AO), The Bone & Joint Journal (BJJ), and Clinical Orthopaedics and Related Research (CORR). The gender of primary and senior authors, as well as the geographical and developmental status of their countries, were collected. The Namsor application, along with additional sources, was used to assign author gender. Country development status was determined by the Human Development Index.

Results: The study analyzed 7,381 articles. Female authorship significantly increased over time in all journals analyzed. Female primary authorship rose from 238 (8.9%) in the first period to 495 (24.7%) in the third, and senior female authorship increased from 133 (5.1%) to 287 (14.3%). In AO, female primary authorship saw a 3.4-fold rise, while senior authorship increased 4.9-fold. For BJJ, female primary authorship rose 2.3-fold, while senior authorship increased 1.7-fold. In CORR, primary authorship grew 2.7-fold and senior authorship 3.6-fold. Geographically, Europe was the most prominent contributor to AO and BJJ, while North America led in CORR. Articles from developing countries showed small increases, with China and India being key contributors, especially in BJJ and CORR.

Conclusion: The study highlights a notable rise in female authorship in three orthopaedic journals, based in Europe and North America. The increase in female authors is more closely associated with specific countries rather than entire continents. Despite low representation, articles from developing countries increased in CORR and BJJ. While progress in gender diversity is promising, regional disparities continue to exist.

Aims: This study aimed to biomechanically compare three medial meniscus posterior root tear (MMPRT) repair techniques to support their clinical application.

Methods: A total of 18 porcine knee joints and 12 bovine extensor tendons were allocated into three groups: transtibial pullout repair (TPR), tendon reconstruction (TR), and tendon-suture complex (TSC). Each sample underwent cyclic loading (1 to 30 N, 1,000 cycles), followed by failure testing. Displacement, elongation, stiffness, ultimate load, and failure modes were assessed.

Results: Significant mean differences were detected between the TPR and TSC after 100 cycles (2.27 mm (SD 0.26) vs 1.89 mm (SD 0.20), p = 0.012), and also between the TSC and TPR or TR after 500 and 1,000 cycles (500 cycles: 2.08 mm (SD 0.22) vs 2.62 mm (SD 0.27) and 2.50 mm (SD 0.13), p = 0.001 and p = 0.009, respectively; 1,000 cycles: 2.22 mm (SD 0.21) vs 2.86 mm (SD 0.31) and 2.71 mm (SD 0.20), p = 0.001 and p = 0.011, respectively), while no significant difference was detected between the TPR and TR. The ultimate failure load in the TSC was greater than that in the TR (277.43 N (SD 75.57) vs 176.88 N (SD 36.80), p = 0.038) and did not differ from that in the TPR. TR and TSC presented a lower elongation than that noted in the TPR (14.09 mm (SD 4.32) and 13.88 mm (SD 4.59) vs 26.89 mm (SD 7.27), both p = 0.003), with no difference noted between TR and TSC. Stiffness was greater with the TSC than with TPR (23.82 N/mm (SD 6.94) vs 14.34 N/mm (SD 2.39), p = 0.028) and did not differ between TPR and TR or between TR and TSC. Failure modes varied: TPR failure by suture pull-through, and TR and TSC failure by tendon pull-through.

Conclusion: TR and TSC outperformed TPR, with TSC resulting in better displacement, elongation, and stiffness, and a higher ultimate failure load than TR. These findings suggest that suture augmentation enhances repair strength. TSC shows favourable biomechanics, but further clinical validation and rehabilitation optimization are needed for better long-term outcomes.

Aims: Chronic periprosthetic joint infections (PJIs) caused by low-virulence pathogens can be challenging to differentiate from aseptic failure. The aim of this study was to assess the diagnostic accuracy of the most commonly used tests for diagnosing these PJIs.

Methods: A consecutive series of 420 patients undergoing revision total hip or knee arthroplasty were studied. Coagulase-negative staphylococci, Cutibacterium spp., enterococci, Actinomyces spp., and fungi were classified as low-virulence pathogens. Of the 207 PJIs defined by the European Bone and Joint Infection Society (EBJIS) criteria, 60 were chronic infections caused by low-virulence pathogens. A total of 213 cases were classified as aseptic, resulting in a total of 273 cases included in the analysis. The performance of established test methods was assessed using receiver operating characteristic (ROC) curves.

Results: The calculated synovial fluid percentage of polymorphonuclear neutrophils (SF-%PMN) cut-off of > 67% demonstrated the best preoperative performance with a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) of 97.1% (95% CI 83.9 to 100), 97.2% (95% CI 91.9 to 100), 97.1% (95% CI 91.6 to 100), 97.2% (95% CI 91.9 to 100), and 0.972 (95% CI 0.933 to 1.000), followed by SF white blood cell count (SF-WBC) > 2,403 cells/µl with estimates of 85.4% (95% CI 71.1 to 93.4), 100% (95% CI 94.6 to 100), 100% (100), 93.3% (95% CI 88.0 to 98.5), and 0.927 (95% CI 0.872 to 0.982). While a %PMN cut-off of > 67% outperformed the established threshold of > 80% (p = 0.010), the calculated SF-WBC cut-off of > 2,403 G/l did not perform significantly better than the established threshold of > 3,000 G/l (p = 0.266). Intraoperatively, permanent paraffin-fixed sections showed the best accuracy with performance values of 89.3% (95% CI 78.1 to 95.3), 100% (95% CI 97.7 to 100), 100% (100), 97.1% (95% CI 94.8 to 99.4), and 0.946 (95% CI 0.906 to 0.987), followed by frozen sections (85.7% (95% CI 67.7 to 94.6), 99.2% (95% CI 95.1 to 100), 95.8% (95% CI 87.8 to 100), 96.9% (95% CI 94.0 to 99.9), and 0.922 (95% CI 0.853 to 0.991)).

Conclusion: Synovial fluid %PMN and WBC, and permanent histological sections demonstrated the highest diagnostic performance for diagnosing PJI caused by low-virulence pathogens. Intraoperative frozen sections proved to be a valuable intraoperative tool, particularly in cases with unclear preoperative diagnosis. A lower cut-off for SF-%PMN may be considered to more accurately diagnose these infections.

Aims: Melatonin (MEL) has been investigated as a strategy to prevent bone loss related to oestrogen deficiency. However, its systemic impact on multiple bone properties is not completely established. This study evaluated the effects of chronic MEL administration on bone parameters commonly compromised by hypoestrogenism, using complex network analyses as an innovative approach to integrate bone outcomes.

Methods: A total of 40 female Wistar rats were allocated into four groups: control + vehicle (CG), ovariectomized + vehicle (OG), melatonin (MG), and ovariectomized + melatonin (MOG). OG and MOG underwent bilateral ovariectomy (OVX) at 15 weeks of age. One week later, animals received daily melatonin (MG and MOG, 10 mg.kg^-1) or vehicle (CG and OG) via orogastric gavage during the dark period for 12 weeks. At the end, bilateral femora were collected for metric, physical, mechanical, chemical, and micro-CT analyses. Two-way analysis of variance (ANOVA) was conducted and parameter interactions were explored with complex network analyses with PageRank and Betweenness centrality metrics.

Results: Traditional analyses confirmed that OVX impaired bone health, while MEL treatment improved mechanical strength and preserved bone properties. Overall, treated animals exhibited values closer to CG than to OG and complex network analyses elucidated the physiological adjustments in response to interventions. Centrality metrics indicated that MEL modulated parameters to enhance the bone's load-bearing capacity, while biophysical aspects were more central in other groups and became key connectors in MG with Betweenness centrality.

Conclusion: Our results suggest that MEL administration positively influences bone mechanics under different stress conditions and prevents deterioration related to osteometabolic disorders caused by OVX. Complex network analyses highlighted biomechanical variables as central in groups treated with MEL, while biophysical variables acted as key connectors. These findings provide an integrative understanding of the physiological adaptations promoted by MEL to maintain bone strength, through reorganization of the functional importance of biomechanical and biophysical parameters under hypoestrogenism conditions over 12 weeks.