Effect of methylprednisolone on reperfusion after femoral head ischemia.

Abstract

An episode of ischemia and reperfusion of the femoral head is thought to be the common pathway in the pathogenesis of femoral head necrosis. The influence of short-term high-dose steroid treatment on femoral head reperfusion after ischemia was investigated in a porcine model. Twenty-two pigs were randomized to receive methylprednisolone 20 mg/day/kg bodyweight intramuscularly for 3 days followed by methylprednisolone 10 mg/day/kg bodyweight for 11 days (n = 11), whereas the control group (n = 11) received no treatment. Femoral head ischemia was achieved by 6 hours of unilateral intraarticular hip pressure increase to 250 mm Hg. Femoral head blood flow was estimated using radiolabeled microspheres (15 microm in diameter) before ischemia, during hip tamponade, and 4 hours after tamponade release. Femoral head blood flow was lower in the corticosteroid treated pigs. Subtotal femoral head ischemia was documented in both groups during joint tamponade. Apart from two femoral head epiphyses in either group, reperfusion after tamponade release on the average occurred to a blood flow level similar to that before ischemia. Short-term high-dose methylprednisolone treatment depressed bone perfusion in general, but had no effect on reperfusion after femoral head ischemia in the porcine model.