Journal of Orthopaedic Surgery and Research最新文献

Background: The kinematics of the wrist have been widely studied in terms of flexion/extension, radial/ulnar deviation, and the dart-throwing motion (DTM); however, the opposite dart-throwing motion (oDTM)-despite its functional importance in daily activities-remains poorly characterized. This study aimed to quantify in vivo kinematics of the radiocarpal and midcarpal joints and to characterize their motion patterns during oDTM.

Methods: In vivo kinematics of eleven wrists from healthy subjects were assessed using four-dimensional computed tomography (4D CT). A custom-designed device guided wrist motion along a plane oriented 45° in supination from the sagittal plane. Three-dimensional bone models were reconstructed to calculate the Euler angles and translational displacements of the third metacarpal, proximal carpal row, and distal carpal row. Throughout the arc of motion, the contributions of the radiocarpal and midcarpal joints were compared.

Results: The actual oDTM of the subjects was performed within a plane supinated 50.3 ± 7.0° [95% confidence interval (CI): 45.6° to 55.0°] from the sagittal plane, with a motion arc of 59.9 ± 10.3° [95% CI 53.0° to 66.8°]. During ulnar extension, the proximal carpal row underwent extension, supination, and ulnar deviation relative to the radius, while the distal carpal row flexed, pronated, and deviated ulnarly relative to the proximal row. During radial flexion, the proximal carpal row flexed, pronated, and deviated radially, except for the lunate which deviated ulnarly. Relative to the scaphoid, the trapezium, trapezoid, and capitate extended, supinated, and deviated radially. The capitate and hamate flexed, supinated, and deviated radially relative to the lunate and triquetrum, respectively. Translational displacements were generally less than 5 mm. Throughout the oDTM, the radiocarpal joint contributed predominantly to extension/flexion, whereas the midcarpal joint contributed substantially to radial/ulnar deviation.

Conclusion: During the oDTM, the radiocarpal joint exhibited motion consistent with the oDTM plane, while the midcarpal joint-particularly on the radial side-demonstrated motion more characteristic of the classical dart-throwing motion (DTM). Both the radiocarpal and midcarpal joints play integral and complementary roles in facilitating wrist oDTM. However, due to the relatively small sample size (n = 11) and the homogeneous cohort, the generalizability of these findings to broader or more diverse populations may be limited.

Background: The proximal femoral lateral wall serves as a critical "lateral pillar" in the mechanical stability of intertrochanteric fractures, and variations in its thickness may profoundly influence the biomechanical behavior of different intramedullary fixation systems. However, previous studies have largely assessed the lateral wall in a binary manner, lacking systematic evidence based on continuous gradients. This study aimed to elucidate the biomechanical coupling between lateral wall thickness and three mainstream intramedullary fixation systems (PFNA, PFBN, and InterTan) using high-resolution finite element models, and to delineate the optimal lateral wall domains for each system.

Methods: Sixteen continuous gradient models of the lateral wall, ranging from + 35 mm to - 20 mm, were constructed and implanted with PFNA, PFBN, or InterTan. Under three typical loading conditions-standing, slow walking, and fast walking-the maximum equivalent stress of the lag screw/main nail, overall displacement fields, and the mechanical response trajectories and instability trends of each fixation system during lateral wall thinning were analyzed and compared.

Results: Lateral wall thickness significantly affected the overall mechanical stability of intertrochanteric fractures. With progressive thinning, all three fixation systems exhibited increasing stress concentration and displacement. This relationship was nonlinear, with accelerated deterioration observed once the lateral wall was reduced below specific thresholds. Among the devices, PFBN maintained more uniform load distribution across the full gradient range, sustaining relatively low implant stress and minimal fracture gap displacement even with weak or absent lateral walls. InterTan demonstrated intermediate stability between PFBN and PFNA, with stress and displacement changes occurring more gradually during wall thinning. In contrast, PFNA was more sensitive to lateral wall deficiency, showing pronounced displacement increases under extremely thin wall conditions.

Conclusion: Finite element analysis indicates that lateral wall thickness is a decisive factor for the fixation stability of intertrochanteric fractures. Progressive thinning leads to marked increases in stress and displacement for all intramedullary devices, accompanied by characteristic mechanical critical points. PFBN provides superior stability under weak or absent lateral wall conditions, whereas PFNA and InterTan are more sensitive to lateral wall structural variations. These findings suggest that lateral wall thickness should be a core parameter in selecting fixation methods and formulating postoperative weight-bearing strategies, providing critical biomechanical evidence for individualized management of unstable intertrochanteric fractures.

Background: Percutaneous vertebroplasty (PVP) is highly effective treatment for osteoporotic vertebral compression fractures (OVCF). There is no clear conclusion regarding the common locations of fractures, and whether recurrent fractures are related to surgery, or changes in local spinal alignment.

Methods: A total of 164 patients with thoracolumbar OVCF from June 2020 to June 2024 were enrolled. The segmental distribution with initial and recurrent fractures were collected. The impact of surgery on recurrent fractures was analyzed by comparing the segmental distribution of recurrent fractures between groups. 84 patients with T11-L2 OVCF were divided into two groups based on recurrent fractures or not. The gender, age, trauma of patients were measured, imaging indicators including bone cement distribution type, T11-L2 Cobb angle, Cobb angle and height recovery rate of fractured vertebra, and vertebral CT value were measured at the time of initial fracture, immediately after surgery, and recurrent fracture. The influencing factors of recurrent OVCF were explored through inter-group comparative analysis.

Results: Both initial and recurrent fractures mostly occurred in the T11-L3, accounting for 80.4% and 63.1%, respectively. In the non-surgical group, the recurrent fractures were found mostly at L1 and L2 levels, accounting for 21.6%; while in the surgical group, the fractures occurred mostly at L1 level, accounting for 14.0%. In 84 patients with T11-L2 OVCF, among surgical patients, average age in the recurrent fracture group was 8.4 years older(P<0.001), and the average CT value was 22.9 HU lower (P =0.012) than that in the non-recurrent group. For each 1-year increase in age, the risk of recurrent fractures increased by 7.1%; for each 1 HU decrease in CT value, the risk of recurrent fractures increased by 2.1%. In addition, 78.6% of patients with initial fractures had a history of trauma, and 64.7% of patients with recurrent fractures had a history of trauma.

Conclusions: Initial and recurrent OVCF of the thoracolumbar spine commonly occurred in T11 to L3 segments. The segment of initial fracture and surgical treatment were not associated with recurrent fracture location or risk. Advanced age and decreased CT value are risk factors for recurrent fractures. The occurrence of the fracture, mostly depends on the presence of trauma. REGISTRY: www.chictr.org.cn, TRN: ChiCTR2500105987, Registration date: 27 June 2025.

Background: The Latarjet procedure is a well-established surgical technique for the treatment of recurrent anterior shoulder instability. Endobutton fixation systems have recently emerged as an alternative to conventional screw fixation, with the potential advantage of providing a more homogeneous stress distribution across the graft. The purpose of this study was to compare the distribution of Von Mises stress (VMS) in coracoid grafts fixed with screws versus endobuttons using three-dimensional finite element (FE) analysis.

Methods: Three-dimensional FE models of the glenoid and coracoid graft were constructed using computed tomography data. Two fixation scenarios were evaluated: [1] Group A - fixation with two cortical screws, and [2] Group B - fixation with an Endobutton system. Identical graft dimensions, positions, and loading conditions were applied. A 50-N anteriorly directed force was applied at the graft-glenoid interface. Material properties were defined as homogeneous, isotropic, and linearly elastic. VMS values were calculated using Abaqus software.

Results: Screw fixation produced localized stress concentrations around the screw holes with limited proximal load transfer, resulting in a heterogeneous graft stress pattern. In contrast, the Endobutton construct demonstrated a more uniform stress distribution across the graft. Although the screw group exhibited a higher mean von Mises stress (16.7 MPa [0.8-23.1]) compared with the Endobutton group (12.3 MPa [5.4-20.9]), a substantially greater proportion of graft volume exceeded the predefined high-stress threshold (≥ 15 MPa), indicating localized stress concentration. The Endobutton model showed fewer high-stress regions and improved stress homogeneity.

Conclusion: Endobutton fixation in the Latarjet procedure results in a more uniform stress distribution across the coracoid graft than screw fixation, which may reduce the risk of graft osteolysis and enhance osteointegration. These findings warrant further validation with cadaveric and clinical studies.

Purpose: Radiostereometric analysis (RSA) has been the gold standard for implant migration analysis for decades. Our group previously demonstrated in a porcine cadaver model that CT-RSA precision was non-inferior by dose reduction. The aim of this study was to investigate whether this finding applied in a clinical setting.

Methods: This study is part of the ClessTKA trial comparing a novel 3D printed uncemented medially stabilized total knee arthroplasty (TKA) with Tritanium TKA. Fifty patients were recruited (GMK Sphere n = 26, Tritanium n = 24). All surgeries were performed with mechanical alignment between January and June 2023. CT acquisitions were performed postoperatively within 2 days (standard dose 0.05 mSv, n = 49) and at 1 year (low dose 0.01 mSv, n = 47) using a GE Revolution scanner. CT-RSA analyses of tibial components were performed with Sectra CTMA software by a certified assessor. The primary endpoint was difference in precision (mean) of maximum total point motion (MTPM) between dose levels, with an equivalence interval of 0-0.1 mm.

Results: Mean difference (95% CI) in MTPM under zero motion circumstances between standard and low dose was 0.007 mm (- 0.018 to 0.032). No clinically meaningful differences were found for migration or rotations. Centre-of-mass analysis showed one significant but clinically irrelevant posterior translation (0.013 mm).

Conclusion: The findings confirm that reducing the effective radiation dose from 0.05 mSv to 0.01 mSv does not compromise the precision of CT-RSA for tibial components in TKA. The results further support the use of low-dose CT-RSA protocols in clinical studies, enabling substantial reduction in patient radiation exposure without loss of precision.

Trial registration: Clinicaltrials.gov identifier NCT05651009. Initial release of the study was November 23, 2022. At that time, the software CTMA (Sectra) did not provide the very important Maximum Total Point Motion (MTPM), this was introduced in a later update of the CTMA. Hence there was change in the original protocol retrospectively.

Background: Thoracic spinal stenosis (TSS) is a severe spinal disorder that can lead to thoracic myelopathy, particularly in non-ambulatory patients. Thoracic ossification of the posterior longitudinal ligament (T-OPLL) and thoracic ossification of the ligamentum flavum (T-OLF) are the primary etiologies, but their differences in clinical characteristics and surgical outcomes remain unclear. This study aimed to compare the clinical features and surgical efficacy between non-ambulatory T-OPLL and T-OLF patients.

Methods: A retrospective analysis was conducted on 126 non-ambulatory patients (70 in T-OPLL group, 56 in T-OLF group) who underwent decompression surgery between 2012 and 2023. Demographic data, surgical details, perioperative complications, and neurological outcomes were compared between groups.

Results: T-OPLL patients were younger (51.3 vs. 58.2 years, P < 0.001) and more frequently female (74.3% vs. 48.2%, P = 0.003). Despite worse preoperative mJOA scores (median 3.0 vs. 3.0, P = 0.03), T-OPLL patients achieved higher recovery rates (62.5% vs. 50.0%, P = 0.042) at final follow-up. T-OPLL surgeries required more decompressed segments (4.5 vs. 4.0, P = 0.02) and longer operative times (134.5 vs. 111.0 min, P = 0.02), with higher rates of transient neurological deterioration (22.9% vs. 5.4%, P = 0.006).

Conclusions: Non-ambulatory T-OPLL patients exhibit distinct demographic profiles and more severe preoperative deficits but demonstrate better postoperative recovery than T-OLF patients. These findings underscore the need for tailored surgical approaches and highlight the potential for neurological improvement even in advanced TSS.

Purpose: This study aimed to evaluate the efficacy and safety of perioperative intravenous dexamethasone (Dexa) in patients with type 2 diabetes mellitus (T2DM) undergoing total hip arthroplasty (THA).

Methods: In this prospective, single-blind randomized trial (Registration No.: MR-45-23-047982; Registration Date: December 7, 2023), 60 T2DM patients undergoing THA were assigned to either the Dexa or control group. Outcomes included white blood cell count (WBC), C-reactive protein (CRP), visual analogue scale (VAS) scores, blood glucose, nausea and vomiting, medication requirements, complications, and hospital stay.

Results: Compared with controls, the Dexa group had lower WBC on postoperative days 2 ~ 3 (day 2: 9.20 ± 1.28 vs.10.56 ± 2.34 × 10⁹/L, P = 0.007; day 3: 8.02 ± 1.34 vs. 9.22 ± 1.49 × 10⁹/L, P = 0.002)and reduced CRP on days 1 ~ 3 (day 1: 38.20 vs. 63.50 mg/L, P = 0.040; day 2: 86.00 vs. 101.50 mg/L, P = 0.010; day 3: 78.00 vs. 95.20 mg/L, P = 0.044). Transient hyperglycemia was observed in the Dexa group on postoperative day 1, with higher median blood glucose (8.90 vs. 8.35 mmol/L, P < 0.01) and peak glucose (11.80 vs. 10.35 mmol/L, P = 0.031) but showed no differences thereafter. VAS pain scores at rest and during activity were lower in the Dexa group on postoperative days 1 ~ 2 (all P < 0.01). Dexa reduced the need for rescue tramadol (4 vs. 12 patients, P = 0.020) and metoclopramide (1 vs. 8 patients, P = 0.026), and lowered PONV incidence (3.33% vs. 23.30%, P = 0.026). Hospital stay was shorter in the Dexa group (5.67 ± 1.13 vs. 6.70 ± 1.29 days, P = 0.002), with no differences in 90-day complications (all P > 0.05).

Conclusion: Perioperative Dexa administration improves early recovery outcomes in patients with T2DM undergoing THA without compromising short-term safety, although it may cause transient hyperglycemia. However, the relatively small sample size, limited follow-up period, and lack of systematic evaluation of potential complications highlight the need for larger, longer-term studies to further strengthen these observations.

Background: Reverse shoulder arthroplasty (RSA) is a promising option for proximal humerus fractures (PHFs) and also used as a salvage procedure for failed treatment. Whether the timing of RSA would influence the clinical outcomes is controversial. This meta-analysis compared outcomes between immediate RSA (iRSA) and salvage RSA (sRSA) in geriatric patients with PHFs.

Methods: PubMed, Embase, Web of Science and Cochrane Library databases were searched up to 1st April 2024. Comparative studies reporting outcomes of iRSA and sRSA in geriatric patients with PHFs were included. A random-effects model was used for meta-analysis. The primary outcome was the revision rate. Secondary outcomes included shoulder function and complications. Risk ratios (RR) were calculated for dichotomous outcomes, and weighted mean differences (WMDs) were used for continuous variables. Meta-regression model and subgroup analysis were used to explore sources of potential heterogeneity for the primary outcome.

Results: Seventeen studies with 27,756 cases (24442 receiving iRSA and 3314 receiving sRSA) were included. Compared with sRSA, iRSA was associated with a lower risk of revision (RR = 0.41, P < 0.001), greater range of motion (ROM) (abduction: WMD = 11.32°, P < 0.001; forward flexion: WMD = 11.51°, P < 0.001; external rotation: WMD = 3.77°, P = 0.048) and statistically superior shoulder functional scores (Constant-Murley score: WMD = 5.57, P < 0.001; American Shoulder and Elbow Surgeons score: WMD = 10.38, P < 0.001; Simple Shoulder Test score: WMD = 0.91, P = 0.001; Shoulder Pain and Disability Index: WMD = - 14.50, P < 0.001), and lower risk of complications (infection: RR = 0.42, P = 0.019; dislocation: RR = 0.34, P = 0.007; nerve palsy: RR = 0.49, P = 0.026). The meta-regression model and subgroup analysis showed that sRSA after failed prior surgery had the highest revision rate (9.4%) as compared with iRSA (3.7%).

Conclusions: In elderly patients with PHFs, iRSA is associated with lower revision and complication rates, as well as statistically superior shoulder function and ROM, compared with sRSA. However, the clinical significance of some functional differences remains uncertain.

Trial registration: CRD42024534751.

Background: Osteoarthritis (OA) is a degenerative disease with incompletely understood mechanisms. The proteasome subunit PSMB9 has been implicated in immune regulation, but its specific role in OA pathogenesis remains unclear. This study aimed to investigate whether PSMB9 mediates IL-1β-induced chondrocyte injury by activating the NF-κB pathway through promoting IκBα degradation, and to explore the regulatory relationship between IL-6 and PSMB9 in OA progression.

Methods: Differentially expressed genes were identified by integrating human and mouse OA datasets. A mouse destabilization of the medial meniscus (DMM) model was established. The function of PSMB9 in OA chondrocytes and its effect on the NF-κB pathway were analyzed using hematoxylin-eosin (H&E) staining, immunohistochemistry, Western blot, CCK-8, Edu, flow cytometry, and immunofluorescence to observe p65 nuclear translocation.

Results: (1) PSMB9 was significantly upregulated in multiple OA datasets and models; (2) PSMB9 expression increased in the cartilage of OA patients and mice; (3) PSMB9 overexpression exacerbated IL-1β-induced chondrocyte apoptosis, inhibited proliferation, upregulated the expression of the inflammatory factor IL-6 and the matrix-degrading enzyme MMP13, promoted extracellular matrix (ECM) degradation, and decreased COL2A1 expression; (4) PSMB9 activated the NF-κB pathway by promoting IκBα degradation, and inhibition of this pathway alleviated cell injury; (5) silencing IL-6 reduced PSMB9 expression.

Conclusion: PSMB9 may participate in the activation of the NF-κB pathway and potentially contribute to chondrocyte injury in OA, making it a promising target for future research.

Background: This study aimed to investigate the association between specific fracture line distributions and patellar fracture malreduction by generating patellar fracture maps and analyzing preoperative and postoperative computed tomography (CT) data. The goal was to identify risk factors influencing postoperative patellar malposition to guide surgical management and improve prognosis.

Methods: Imaging data of 193 patients with patellar fractures who underwent surgical treatment at Hebei Medical University Third Hospital from January 2020 to May 2025 were reviewed. Patellar fractures were virtually reconstructed and reduced using Mimics 21.0 software. Fracture lines were superimposed onto a standard template to establish a 3D fracture map for distribution analysis. Postoperative patellar positional changes were assessed using X-ray and CT measurements. Correlations between fracture line characteristics and postoperative malposition were analyzed.

Results: A total of 193 patients (118 males, 75 females; mean age: 51.30 ± 12.59 years) were included. Transverse fractures (n = 141) primarily involved the mid-lower poles with higher fracture line density on the lateral surface. Comminuted fractures (n = 42) exhibited a radial distribution concentrated in the center; the inferior non-articular zone was prone to laminar and comminuted patterns. Fracture mapping revealed a distinct isolated medial fragment formed by intersecting fracture zones in the medial upper-middle 1/3 of the patella. This isolated medial fragment was significantly associated with postoperative lateral displacement (P < 0.001). Additionally, laminar and comminuted fractures of the inferior pole were significantly correlated with postoperative inferior displacement (P < 0.001). A significant difference in the inferior pole distance was observed between patients with and without postoperative inferior displacement (38.39 ± 5.25 mm vs. 42.68 ± 5.88 mm, P < 0.001). Gender was not associated with malposition (P > 0.05).

Conclusions: Fracture line mapping effectively elucidates the distribution characteristics of patellar fractures. The presence of an isolated medial fragment serves as an indicator of increased risk for postoperative lateral patellar displacement. Consequently, intraoperative management should prioritize the minimization of soft tissue stripping and the secure fixation of this fragment; when necessary, imbrication of the medial soft tissues should be performed to maintain patellar alignment. For comminuted fractures, particularly those involving lamination and comminution of the non-articular surface of the inferior pole, achieving sufficiently rigid fixation is essential. Such reinforced stability is likely required to minimize the risk of elongation, serving as the prerequisite for safe, early functional rehabilitation.