Etiology of Osteoarthritis of the Knee with Disappearance of the Anterior Cruciate Ligament and Clinical Results of High Tibial Osteotomy

Abstract

We evaluated the clinical results of high tibial osteotomy performed between 1975 and 1989 for osteoarthritis of the knee in which disappearance of the anterior cruciate ligament was verified during the operation. There were 12 knees in 11 women, with a mean age at operation of 65.1 (range : 52 to 77) . The mean length of follow-up was 3.2 years (range : 1.4 to 6.8) . We contrasted this ACL (-) group with a group that had no disappearance of ACL. In this ACL (+) group there were 231 knees of 163 cases (34 men, 129 women), whose mean age at operation was 63.4 (range : 43 to 80) . The mean length of follow-up was 5.1 years (range : 1.0 to 13.2) .
The frequency of steroid injection into the knee in the past was higher in the ACL (-) group than in the ACL (+) group (p<0.01) . The Yokohama City University radiographic knee osteoarthritis grades at preoperation were also more progressive in the ACL (-) (p<0.01) . The average of the posterior inclination angle of the tibial plateau in lateral radiographs in the ACL (-) group was 15.4±2.9° and larger than the 9.2±3.4° in the ACL (+) group (p<0 .01) . The average femoro -tibial angle (standing) in antero -posterior radiographs was 195.4±5.4° in the ACL (-) group and 185.2±5.1° in the ACL (+) group. The preoperative alignment of the knee in the ACL (-) group was also more varus (p<0.01), but the average of this angle at follow-up was 169.4±5.7° in the ACL (-) group and 167.7±57° in the ACL (+) group. The average clinical score with the Japanese Orthopaedic Association Criteria for Evaluation of Osteoarthritis of the Knee was 60±11 points in both ACL (-) and ACL (+) groups at preoperation and was 84±11 points in the ACL (-) group and 85±11 points in the ACL (+) group at the time of follow-up.