To investigate the method and cl inical effect of double-plating fixation in treatment of distal humerus fractures. Methods From April 2003 to January 2009, 21 patients with distal humerus fracture were treated with l imited contact compression plate and reconstruction plate via posterior elbow incision and approach inside and outside the edge of both sides of the triceps. There were 12 males and 9 females, aged from 20 to 63 years (39 years on average). The causes of injury were fall ing in 13 cases, traffic accident in 6 cases, and fall ing from height in 2 cases. According to the classification of Association for the Study of Internal Fixation (AO/ASIF), 8 cases were classified as type 12-B1, 2 as type 12-B2, 7 as type12-B3, 3 as type 13-A2, and 1 as type 13-A3. The course of disease averaged 4.8 days. Results Secretion was observed at incision in 1 case 2 weeks after operation, and incision healed after dressing change; other incisions healed by first intention. Transient numbness of ring and l ittle fingers occurred in 2 cases 2 days after operation; no iatrogenic nerve paralysis occurred. All patients were followed up 13 to 18 months (15 months on average). The X-ray films showed bone healed 6 months after operation. No postoperative joint adhesion occurred, and the motion of elbow joint ranged from 0° to 135°. According to Morrey evaluation standard, the results were excellent in 17 cases, good in 2 cases, and fair in 2 case; the excellent and good rate was 90.5%. Conclusion Double-plating fixation has the advantages of wide indications, rigid internal fixation, and significant curative effects in treatment of distal humerus fractures.
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 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 controled 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.