[Autologous concentrated bone marrow graft in the treatment of femoral head avascular necrosis: clinical outcome after two years of follow up in a non-controlled prospective study]

Objective: To assess the efficacy of implanting concentrated bone marrow rich in mesenchymal stem cells (MSC) for the treatment of femoral head avascular necrosis (AVN) to prevent or delay total hip replacement (THR).

Material and methods: A single-centre, prospective, non-controlled clinical study was conducted on patients with a diagnosis of AVN. The parameters assessed were, patient demographics, Harris Hip Score (HHS), imaging test (X-ray and NMR), and staging using the Arlet-Ficat scale. The patients were followed up for 1, 6, 12 and 24 months. The bone marrow was aspirated from the iliac crest, concentrated with the Harvest SmartPReP 2 system, and infused into the necrotic area by means of core decompression.

Results: A total of 22 hips in 17 patients were recruited between the years 2006 to 2012, with a minimum follow-up of 2 years. A mean of 119.5 mL of aspirate was extracted, with 15.25 ml of MSC being implanted. During the first 2 years of the infusion, 5 hips (24.7%) required THR, with no differences in the baseline Arlet-Ficat stage, and 4 of these (80%) had femoral head involvement equal to or higher than 30%. A significant increase of 14.27 (P=.026) in the HHS and a 0.98 (P=.089) decrease in the VAS was observed two years after the infusion in the remaining 17 hips. The results suggest that the infusion of concentrated bone marrow rich in MSC, combined with surgical decompression of the nucleus, improves hip function (HHS), and avoids THR in 75.3% of patients with AVN treated during the first 2 years.