Humeral nonunion.

Humerus fractures comprise 5% to 8% of all fractures. Although uncommon, nonunions can present a frustrating challenge to the orthopedic surgeon. Various risk factors that may predispose patients to nonunion include obesity, osteoporosis, alcoholism, smoking, poor bone quality, and scar tissue. Many methods of treatment have been described with various degrees of success. The rates of healing of humeral nonunions by traditional means of internal fixation with bone graft range from 70% to 92%, although in cases of infection, poorly vascularized beds, and open, segmental, or severely comminuted fractures, secondary bony healing may still be compromised.