Dysbaric Osteonecrosis

Abstract

To perform a general literature review of dysbaric osteonecrosis (DON) to describe its pathophysiology, prevalence in scuba divers, prognosis, and treatment options. A literature search on PubMed was performed using the term "dysbaric osteonecrosis" yielding 67 results. There was no exclusion based on dates. Articles that mainly dealt with decompression sickness secondary to tunnel work, mining, or airplane travel were not selected. An additional search on PubMed using the terms "(osteonecrosis diving) NOT dysbaric" was performed to identify other publications not picked up in the initial search. Dysbaric osteonecrosis is associated with prolonged hyperbaric exposure and rapid decompression that cause nitrogen bubbles to enter the fatty marrow-containing shafts of long bones leading to reduction in blood flow and subsequent osteonecrosis. Patients may present asymptomatically, and typical radiographic findings of DON include: decalcification of bone, cystic lesions, osteosclerotic patterns, nontraumatic fractures, bone islands, and a subchondral crescent sign. Surgical treatment options are comprised of core decompression and free vascularized fibular graft, whereas nonsurgical treatment options consist of monitoring, physical therapy, and bisphosphonate therapy. Although the incidence of DON has decreased significantly over the past 2 decades, the lack of timely diagnosis and optimal management keeps DON relevant in the orthopedic and sport medicine community.