Coronal shear fracture of the humeral trochlea.

PURPOSE To review records of 5 patients with anterior coronal trochlear fractures. METHODS Four men and one woman aged 25 to 46 (mean, 34) years underwent cancellous screw (n=3) or Kirschner wire (n=2) fixation for anterior coronal fractures of the humeral trochlea after falling on a flexed elbow. Patients were operated on through a medial approach. Three patients who had a large osteochondral fragment underwent fixation using 4-mm AO partially threaded cancellous screws. Two patients who had a small un-amenable osteochondral fragment (with articular cartilage damage) underwent fixation using Kirschner wires. Patients were evaluated using the Mayo Elbow Performance Index (MEPI) based on pain, arc of motion, stability, and functional disability. RESULTS The mean time from injury to surgery was 7 (range, 5-10) days. The mean follow-up period was 2.7 years. No patient had any wound-related problems, postoperative neurovascular compromise, or avascular necrosis. Radiographic union was noted after a mean of 14 weeks. Outcome was excellent in 4 patients and good in one. The mean arc of flexion-extension was 101º and the mean arc of supination-pronation was 130º. The mean MEPI was 92. The MEPI was relatively low in the 2 patients with a small osteochondral fragment who underwent Kirschner wire fixation. One patient with articular cartilage damage developed mild degenerative changes and had to change his occupation. The remaining 4 patients were pain-free and had returned to their occupations within 4 months. CONCLUSION Open reduction and screw fixation restores articular congruency and enables early mobilisation. Small coronal shear fractures of the trochlea not amenable to screw fixation should be fixed with Kirschner wires.