Avascular Necrosis of the Femoral Head

In avascular (aseptic) necrosis, part of a bone loses its blood supply and dies; in the hip, the femoral head can eventually collapse, often leading to joint replacement. HBOT has been studied in early-stage disease as a way to relieve pain and support repair of the bone. The UHMS lists avascular necrosis among its approved indications (No. 15), but it is not on the US FDA's list of cleared uses and Medicare does not cover it.

In a small double-blind randomised trial, 20 patients with Ficat stage II femoral head necrosis received 30 sessions of hyperbaric oxygen or compressed air over six weeks: pain improved significantly with oxygen after 20 treatments, and seven years later none had required hip replacement — although after six weeks the air group was offered oxygen, so long-term follow-up was not controlled (Camporesi 2010). A 2021 meta-analysis of 10 cohort studies (368 treated patients and 353 controls; seven of the studies from China) found significant clinical improvement with HBOT, but the benefit was not significant in non-Asian patients (Paderno 2021). A 2025 meta-analysis of 10 studies (568 participants) found improvement from baseline but no difference between HBOT and non-HBOT groups, and concluded that HBOT cannot be regarded as an effective treatment for early-stage femoral head necrosis (Cao 2025).

The evidence is therefore conflicting and largely observational. One protocol studied — not a clinical recommendation — used two cycles of 30 daily sessions of 90 minutes at 2.5 ATA, with a 30-day break between cycles (Bosco 2018).