Risk factors, treatment, and outcomes associated with nonunion of the midshaft humerus fracture.

Charts of 28 patients with a diagnosis of delayed union or nonunion were reviewed. There were four delayed unions and 25 nonunions. Comorbidities, risk factors, treatments, and outcomes were evaluated. Comorbidities were common and included cardiovascular, pulmonary, and renal compromise, as well as endocrinopathies and rheumatologic disease. Consensus risk factors included: unstable fractures (comminuted or short oblique, 83% (24/29); advanced age, 57% (16/28); obesity, 35% (9/28); daily tobacco use, 38% (10/28); and multiple long bone fractures, 21% (6/29). Sixty-nine percent (20/29) of the fractures united; 21% (6/29) failed to heal. Healing outcome for 11% (3/29) could not be determined because of death or loss to follow-up. Patients presenting for primary treatment with any of the aforementioned risk factors should be cautioned regarding possible nonunion.