The effect of hyperbaric oxygen therapy on lesion size in early-stage femoral head avascular necrosis

Introduction: Femoral head avascular necrosis (AVN) is a common orthopaedic condition that occurs when intraosseous microcirculation is compromised. Hyperbaric oxygen therapy (HBOT) increases tissue oxygen concentration, reduces oedema, stimulates angiogenesis, lowers intraosseous pressure, and enhances microcirculation. The aim of this study was to evaluate the effectiveness of HBOT in early femoral head AVN based on magnetic resonance imaging (MRI) findings. Methods: A total of 37 hips from 25 patients with Ficat Stage 1−2 femoral head AVN, followed between 2018 and 2021 and receiving HBOT at Kayseri City Training and Research Hospital, were retrospectively included. Thirty HBOT sessions of 90 minutes each were administered at 243 kPa pressure (2.4 atmospheres absolute) with 100% oxygen breathing, along with a weight-bearing restriction protocol. Results: There were 20 females and five males. The mean (standard deviation) age was 46.9 (9.5). In pre-treatment MRI imaging, the mean lesion size was 29.87 (22.64) cm3 in 20 right hips and 28.84 (14.95) cm3 in 17 left hips (P = 0.183). At the second month after treatment, the lesion size was 12.39 (11.26) cm3 in 20 right hips and 21.81 (13.56) cm3 in 17 left hips (P < 0.001). The mean pre-post differences for the right and left hips was 17.48 (21.15) cm3 and 7.02 (5.95) cm3 respectively (both P < 0.001). Conclusions: Femoral head AVN is a progressive disease, with femoral head collapse exceeding 40% in a five-year follow-up. This study demonstrated a reduction in lesion size associated with HBOT in early stage femoral head AVN. In our opinion, HBOT is an integral part of the treatment for early-stage femoral avascular necrosis.