Objective To compare the biomechanical properties of personalized Y-shaped plates with horizontal plates, vertical plates, and traditional Y-shaped plates in the treatment of distal humeral intra-articular fractures through finite element analysis, and to evaluate their potential for clinical application. Methods The study selected a 38-year-old male volunteer and obtained a three-dimensional model of the humerus by scanning his upper limbs using a 64-slice spiral CT. Four types of fracture-internal fixation models were constructed using Mimics 19.0, Geomagic Wrap 2017, Creo 6.0, and other software: horizontal plates, vertical plates, traditional Y-shaped plate, and personalized Y-shaped plate. The models were then meshed using Hypermesh 14.0 software, and material properties and boundary conditions were defined in Abaqus 6.14 software. AnyBody 7.3 software was used to simulate elbow flexion and extension movements, calculate muscle strength, joint forces, and load torques, and compare the peak stress and maximum displacement of the four fixation methods at different motion angles (10°, 30°, 50°, 70°, 90°, 110°, 130°, 150°) during elbow flexion and extension. Results Under dynamic loading during elbow flexion and extension, the personalized Y-shaped plate exhibits significant biomechanical advantages. During elbow flexion, the peak internal fixation stress of the personalized Y-shaped plate was (28.8±0.9) MPa, which was significantly lower than that of the horizontal plates, vertical plates, and traditional Y-shaped plate (P<0.05). During elbow extension, the peak internal fixation stress of the personalized Y-shaped plate was (18.1±1.6) MPa, which was lower than those of the other three models, with significant differences when compared with horizontal plates and vertical plates (P<0.05). Regarding the peak humeral stress, the personalized Y-shaped plate model showed mean values of (10.9±0.8) and (13.1±1.4) MPa during elbow flexion and extension, respectively, which were significantly lower than those of the other three models (P<0.05). Displacement analysis showed that the maximum displacement of the humerus with the personalized Y-shaped plate during elbow flexion was (2.03±0.08) mm, slightly higher than that of the horizontal plates, but significantly lower than that of the vertical plates, showing significant differences (P<0.05). During elbow extension, the maximum displacement of the humerus with the personalized Y-shaped plate was (1.93±0.13) mm, which was lower than that of the other three models, with significant differences when compared with vertical plates and traditional Y-shaped plates (P<0.05). Stress contour analysis showed that the stress of the personalized Y-shaped plate was primarily concentrated at the bifurcation of the Y-shaped structure. Displacement contour analysis showed that the personalized Y-shaped plate effectively controlled the displacement of the distal humerus during both flexion and extension, demonstrating excellent stability. ConclusionThe personalized Y-shaped plate demonstrates excellent biomechanical performance in the treatment of distal humeral intra-articular fractures, with lower stress and displacement, providing more stable fixation effects.
Objective To investigate the surgical method and short-term effectiveness of arthroscopy edge-to-edge #-shaped suture in the treatment of the complete radial tear of the lateral meniscus body. Methods The clinical data of 13 patients with complete radial tear of lateral meniscus body between May 2020 and August 2023 were retrospectively analyzed. There were 10 males and 3 females, aged 15-38 years (mean, 24.2 years). There were 11 cases of acute injury, with time from injury to admission ranging from 2 days to 5 months, and 2 cases of chronic injury, with the time from injury to admission being 3 months and 5 months respectively. All patients had tenderness in the lateral joint space, and 2 patients with chronic injury had positive McMurray’s sign. All patients were treated with arthroscopic edge-to-edge #-shaped suture technique. The knee joint activity, tenderness in the lateral joint space or McMurray’s sign were detected, and the healing of the incision and the occurrence of complications were observed. X-ray films and MRI of the knee joint were performed to evaluate joint degeneration and meniscus healing. Lysholm score, International Knee Documentation Committee (IKDC) subjective function score, Tegner score, and visual analogue scale (VAS) score were used to evaluate the functional recovery before and after operation. Results The operation time ranged from 46 to 100 minutes (mean, 80.8 minutes). All the incisions healed by first intention, and no complications such as intraoperative vascular and nerve injury or postoperative infection occurred. All 13 patients were followed up 20-59 months (mean, 29.3 months). All patients had no tenderness, swelling, and locking in the lateral space. One patient with chronic injury continued to have tenderness in the lateral space of the knee joint, while the remaining patients had no tenderness, swelling, and locking in the lateral space. Immediate postoperative MRI of knee joint showed continuous recovery of the lateral meniscus. At last follow-up, no degenerative changes were observed in X-ray films of knee joint. MRI revealed the changes of lateral meniscus body after repair. Lysholm score, IKDC subjective function score, Tegner score, and VAS score were all significantly improved when compared with those before operation (P<0.05). Conclusion The edge-to-edge #-shaped suture technique can effectively repair the complete radial tear of the lateral meniscus body, and the short-term effectiveness is satisfactory, which can be used as an effective means to repair the meniscus injury.