Multiple drilling compared with standard core decompression for avascular necrosis of the femoral head in sickle cell disease patients

Sickle cell disease (SCD) is the most common cause of avascular necrosis of femoral head (ANFH) in childhood. Advances in medical treatment led to improved life expectancy of such patients. SCD-related ANFH frequently progress to total collapse of the femoral head necessitating hip replacement. However, SCD patient are at more risk of intra- and post-operative complications and suboptimal outcome of total hip arthroplasty. Hence, it is imperative to preserve the femoral head as long as possible.

Between September 1992 and June 2007, 94 core decompression procedures were done to SCD patients who had modified Ficat stage I, II_A and II_B ANFH. Sixty one patients underwent a classical 8-mm drilling and 33 patients underwent 3.2-mm diameter MD technique. Patients were followed up for minimum of 2 years and were evaluated for clinical and Harris Hip Score improvement and for radiological progression.

All 19 hips that had Ficat stage I had significant reduction of pain and improvement of Harris Hip Score. No patient has required further surgery. Among the 39 hips with Ficat II_A at time of procedure, 80 % of hips which underwent CD and 78 % of MD cases had significant reduction of pain and improvement of HHS. Those patients showed no radiographic progression of the disease. The remaining, 20 % CD and 22 % MD eventually progressed radiologically to grade III or grade IV and had HHS less than 75 at last visit. In the 36 cases with Ficat II_B, 52 % CD and 52.8 % MC had significant reduction of pain and improvement of HHS. The rest showed no improvement in pain and function, and progressed to stage IV; 11 of them underwent THA and one patient refused surgery.

While multiple drilling is safer and less invasive than single coring in SCD, there is no statistically significant difference in outcome or complication rate between both procedures done for ANFH in patients with SCD.