Announcing HBO’s Newest Indication: Avascular Necrosis

In the recently published 15th edition of the UHMS Hyperbaric Medicine Indications Manual comes a highly anticipated and newly approved indication for hyperbaric oxygen therapy: avascular necrosis (AVN). Also known as aseptic osteonecrosis, this condition is poorly understood but thought to be due to vascularization in a watershed or terminal vascular area. It presents most commonly in the femoral head but is also seen in other bones of the extremities.

AVN is typically classified by the Ficat system, which relies on the appearance of the bone on x-ray. However, the current gold standard for diagnosis is MRI findings, and the Steinberg staging system includes MRI findings in its classification. Patients with AVN are typically aged 40 to 50 years, but the condition can present in younger patients. The goal of therapy is to reduce pain, improve quality of life, and preserve joint function; both medical and procedural treatments have been studied. End-stage disease is treated by total hip arthroplasty, which requires multiple revisions over time.

The rationale for hyperbaric oxygen (HBO) therapy is that it promotes angiogenesis and bone regeneration. Early studies have shown significant improvement in symptoms and a reduction in the need for surgery in Ficat III patients. It can also be used in conjunction with joint-saving operations, such as core decompression, to improve healing.

The UHMS indications manual recommends that patients be staged properly and directed to make lifestyle modifications prior to HBO therapy treatment. There are three different treatment plan recommendations based on the stage of the disease and, subsequently, three different treatment goals. As more HBO centers begin treating avascular necrosis, I’m sure more information will be forthcoming.

Source: Huang ET, ed. Undersea and Hyperbaric Medicine Society: Hyperbaric Medicine Indications Manual. 15th ed. Best Publishing Company; 2024.