The results of total knee arthroplasty in patients with osteonecrosis of the medial femoral condyle were examined using Kaplan-Meier survival analysis. The study included 32 osteonecrotic knees with an average final follow-up examination of 3.9 years. For comparison, 63 osteoarthrotic knees with an average final follow-up examination of 4.6 years were also analyzed. The survival rates were calculated using four distinct categories of failure: (I) revision, (2) revision or radiolucency, (3) revision, radiolucency, or pain, and (4) pain. On the basis of pain relief alone, the five-year postoperative success rate was 82% for osteonecrosis (eight knees) and 90% for osteoarthrosis (27 knees), with no significant statistical difference between the two groups.
Center for Hip and Knee Surgery, Moores-ville, Indiana and Louisiana State University, Shreve-port, Louisiana.
Reprint requests to Merrill A. Ritter, M.D., Center for Hip and Knee Surgery, 1199 Hadley Rd., Mooresville, IN 46158.
Received: April 5, 1989.