Relationship Between Bone Marrow Edema and Development of Symptoms in Patients With Osteonecrosis of the Femoral Head

Abstract

OBJECTIVE. The purpose of this study was to determine the significance of risk factors on MR images for predicting the outcome of patients with osteonecrosis of the femoral head.SUBJECTS AND METHODS. Eighty-three asymptomatic or minimally symptomatic hips in 61 consecutive patients were followed up prospectively. Inclusion criteria included osteonecrosis of the femoral head identified by typical MRI findings, with no radiographic evidence of progression of collapse, and Harris hip score of 85 points or more. Every 3 months, the patients underwent clinical and radiographic examination, and MR images were obtained at 6- to 12-month intervals. Follow-up continued until worsening of hip pain with Harris hip score of less than 70 points or surgery. Asymptomatic hips were followed up for at least 24 months. The mean clinical and radiographic follow-up period after the initial diagnosis was 60 months (range, 3-168 months).RESULTS. Thirty-six (43%) of the 83 hips were symptomatic at the last follow-up. Bone marro...