Pathogenesis and treatment of osteonecrosis of the shoulder.

Osteonecrosis of the humeral head is an uncommon condition that occurs when bone vascularity is impaired. The causes underlying osteonecrosis of the humeral head seem to be multifactorial and can be traumatic or nontraumatic. Although clinical symptoms and causative factors affect the treatment of each patient, staging is the most objective criterion in deciding on the most appropriate treatment. Conservative treatment can be effective in stages I and II. Surgical intervention is advocated when symptoms are persistent and signs of collapse are evident. The surgical options include arthroscopic débridement, core decompression, vascularized bone grafting, and shoulder arthroplasty.