PURPOSE:Using a finite element (FE) model, we aimed to validate the efficacy of our new additional reduction screw technique to basicervical femoral neck fractures. METHODS:To investigate the biomechanical effects of an additional screw in an FE model of a femoral fracture, we recorded von Mises stress distributions. The fracture was simulated along the trochanteric line, with the additional screw positioned as inferior to the femoral neck as possible without invading the cortical bone. We compared models with and without the additional reduction screw to assess differences in external stress resistance. RESULTS:In the model without the additional screw, stress was distributed along the inferior neck of the fractured femoral head fragment. With the additional screw, stress in this region decreased, leading to better stress redistribution and improved structural integrity. The peak implant stress - particularly at junctions - was lower with the additional screw. Fracture fragment displacement around the femoral head centre was 61.9 mm without the additional screw and 9.5 mm with it. CONCLUSIONS:In basicervical fractures, additional reduction screw fixation enhanced stress distribution across the bone at the fracture site - especially on the anteromedial cortex - reduced implant stress, and minimised fracture fragment movement during cephalomedullary nailing.
BackgroundExtensor carpi ulnaris tenosynovitis (ECUT) is a common cause of ulnar-sided wrist pain and is often associated with tendon hypertrophy. Although extensor carpi ulnaris tendon thickness (ECUTT) has been used to assess tendon enlargement, a one-dimensional measurement may not fully reflect morphological changes of the tendon. We therefore investigated the diagnostic value of extensor carpi ulnaris tendon cross-sectional area (ECUTCSA) measured on magnetic resonance imaging (MRI) as a quantitative imaging biomarker for ECUT.MethodsIn this retrospective case-control study, MRI examinations from 26 patients with clinically diagnosed ECUT and 26 control subjects were analyzed. Axial T1-weighted wrist MR images were reviewed by two musculoskeletal radiologists who were blinded to clinical information. ECUTCSA and ECUTT were measured at the level demonstrating maximal tendon hypertrophy. Group comparisons were performed using unpaired t-tests, and diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis. Interobserver agreement was assessed using intraclass correlation coefficients (ICCs).ResultsThe mean ECUTCSA was significantly greater in the ECUT group than in the control group (10.86 ± 2.32 mm2 vs. 7.25 ± 2.52 mm2, p < 0.001). The optimal ECUTCSA cutoff value was 8.80 mm2, yielding a sensitivity of 84.6%, specificity of 84.6%, and an area under the ROC curve (AUC) of 0.89. The optimal ECUTT cutoff value was 1.98 mm, with an AUC of 0.88. Interobserver agreement was excellent for ECUTCSA (ICC = 0.92) and ECUTT (ICC = 0.88).ConclusionECUTCSA is a reproducible quantitative MRI parameter associated with ECU tenosynovitis and demonstrated good diagnostic performance in this study. These findings support the potential role of ECUTCSA as an imaging biomarker for quantitative assessment of tendon hypertrophy. Further multicenter studies with larger cohorts are warranted to validate its clinical utility.
This study aimed to evaluate the surgical outcomes of MOWHTO in patients categorized based on joint space width (JSW) patterns observed in extension and flexion positions and to identify factors associated with these outcomes. This retrospective study involved 172 patients who underwent MOWHTO between 2016 and 2021. Patients were classified into four groups based on the median values of preoperative medial JSW in extension and flexion positions, measured on standing AP and Rosenberg views, respectively: the extension osteoarthritis (OA) group, the flexion OA group, the minimal JSN group, and the severe JSN group. Perioperative parameters, including demographic data, meniscal status, cartilage grade (International Cartilage Repair Society grading system), knee alignment, and posterior tibial slope (PTS), were analyzed. Clinical outcomes were assessed between groups using the Lysholm score, recorded preoperatively and during follow-ups. Among all enrolled patients, the mean follow-up duration was 3.54 years; the Lysholm score significantly improved from 48.31 preoperatively to 89.32 at 2 years postoperatively. No significant differences in Lysholm scores(P = .795) were observed between the groups postoperatively. PTS showed a negative correlation with extension JSW(R = -.315, P < .001) and a positive correlation with preoperative varus deformity(R = .258, P = .004), as measured with the hip-knee-ankle angle. Additionally, preoperative PTS values differed significantly among the groups, with the flexion OA group exhibiting higher PTS(p < .001). MOWHTO is an effective surgical procedure regardless of knee JSW in extension or flexion positions. PTS was identified as a distinguishing factor for flexion JSN. : Level IV, retrospective therapeutic case series.
