ObjectiveTo evaluate the effectiveness of locking compress plate (LCP) for the treatment of aseptic diaphyseal humeral nonunions. MethodsBetween January 2006 and January 2012, 23 patients with aseptic diaphyseal humeral nonuninons were treated with LCP and autologous iliac crest bone graft, and the clinical data were retrospectively analyzed. There were 15 males and 8 females with the average age of 42.5 years (range, 28-60 years). The fracture located at left side in 11 cases and right side in 12 cases. The mechanism of the injury was traffic accident in 15 patients, and falling from height in 8 patients. Fracture was treated by internal fixation in 20 cases and external fixation in 3 cases. And 6 patients had open fractures and other 17 had close fractures. Based on the Weber-Cech classification, 6 cases were rated as atrophic nonunions, and 17 cases as hypertrophic nonuninons. Shoulder function was evaluated by Constant-Murley score and elbow function was evaluated by Mayo score. ResultsAfter operation, 2 patients had transient radial nerve symptoms of numbness and 1 patient had superficial infection. Primary healing of incision was obtained in the other patients. All patients were followed up 22.22 months on average (range, 16-30 months). Normal range of motion of the shoulder was found in 11 cases; and limited movements of abduction, elevation, and posterior extension were observed in 12 cases. And osseous union was observed clinically and radiographically in all patients. The average union time was 16.95 weeks (range, 12-24 weeks). The average Constant-Murley score was 81.87 (range, 50-98); and shoulder function was excellent in 14 cases, good in 6, and fair in 3. And the average Mayo score was 87.78 (range, 70-96); and the result was excellent in 14 cases, good in 7, and fair in 2. ConclusionAseptic diaphyseal humeral nonunions can be successfully treated with LCP, coupled with the use of autologous iliac crest bone graft.