A new surgical technique for the treatment of supracondylar humerus fracture malunions in children.

PURPOSE To report a new locking lateral closing wedge osteotomy used in repairing pediatric supracondylar humerus fracture malunions, which allows for coronal and sagittal plane correction of both cubitus varus and extension. METHODS At our institution, eight children with cubitus varus resulting from prior supracondylar humerus fracture malunions underwent a new technique of lateral closing wedge osteotomy performed by a single surgeon. Preoperative templating created from radiographs of the bilateral upper extremities were compared with clinical exam to determine the angle of triangular bone that must be removed in order to correct the varus and any extension deformity. A lateral approach and subperiosteal dissection exposed the distal humerus. A transverse osteotomy created a proximal and distal fragment, from which two triangles of bone were removed. The fragments were reunited, parallel lateral pins were placed, and live imaging confirmed stable fixation. RESULTS The osteotomy was performed in eight patients, with an average age of 6.3 years. The mean interval between the initial injury and corrective osteotomy was 2.4 years. All patients ended up with flexion of 130° or greater with full and symmetrical pronation and supination. The average ulnohumeral angular correction was 25.5°, which was within 2° of the uninvolved elbow in seven patients and to within 5° in one patient. Baumann's angle averaged 85.3° preoperatively and 73.7° postoperatively, with an average 70.2° in the uninvolved elbow. All of the patients healed with excellent clinical and radiographic alignment and complete function. There were no complications or revisions. CONCLUSION Varus malunion is a well-described complication of pediatric supracondylar humerus fracture repairs, and many different osteotomy techniques have been described. This series demonstrates that an interlocking lateral wedge osteotomy with parallel lateral pin fixation can provide reliable correction of varus and extension deformity, with a minimal complication rate.