Postoperative alignment of total knee replacement : its effect on survival

Four hundred twenty-one posterior cruciate condylar total knee arthroplasties were performed between 1975 and 1983. Anatomic alignment of the knee was recorded on follow-up evaluations from two months to 13 years postoperatively. Patients were stratified into a normal group that was 5 degrees to 8 degrees anatomic valgus, a varus group that was from 4 degrees anatomic valgus to any degree of varus, and a valgus group that was more than 9 degrees anatomic valgus. There were eight failures, five in the varus group and three in the normal group. There were no failures in the valgus group. Kaplan-Meier survival curves showed no significant difference between normal and valgus groups; however, there was a statistical difference between the valgus and varus and the normal and varus groups. A surgeon should align a total knee prosthesis in neutral or a slight amount of anatomic valgus to give the patient the best chance for long-term survival.