Femoral condylar necrosis: treatment with hyperbaric oxygen therapy

BACKGROUND: Osteonecrosis of the knee (ONK) is a form of aseptic necrosis resulting from ischemia to subchondral bone tissue. Typically, treatment is invasive. Hyperbaric oxygen therapy (HBOT) may provide a noninvasive alternative by improving oxygenation and reperfusion of ischemic areas. This study evaluates the efficacy of HBOT in a series of ONK patients. METHODS: This retrospective study evaluates 37 ONK patients (29 male, 8 female; mean age ± 1 standard deviation: 54 ± 14); 83.7% of patients presented with Aglietti stage I-II; 16.3% presented with Aglietti stage III. Patients were treated with HBOT once a day, 5 days a week, at 2.5 atmosphere absolute with 100% inspired oxygen by mask for an average of 67.9 ± 15 sessions. Magnetic resonance imaging was performed before HBOT, within 1 year after completion of HBOT, and in 14 patients, 7 years after treatment. Oxford Knee Scores (OKSs) were recorded before HBOT and at the end of each HBOT treatment cycle. RESULTS: After the 30 sessions of HBOT, 86% of patients experienced improvement in their OKS, 11% worsened, and 3% did not change. All patients improved in OKS after 50 sessions. Magnetic resonance imaging evaluation 1 year after HBOT completion showed that edema at the femoral condyle had resolved in all but 1 patient. CONCLUSIONS: HBOT is beneficial for treating ONK. Patients experienced improvements in pain and mobility as demonstrated by improvement in OKS. Radiographic improvements were also seen upon post-treatment follow-up. Aglietti staging for the entire sample saw an aggregate decrease (P < .01) from 1.7 ± 0.7 to 0.3 ± 0.6.