Total knee arthroplasty with retention of both cruciate ligaments. A 9 to 11 year follow-up study

Abstract: This is a prospective assessment of 163 total knee arthroplasties in 130 patients with the retention of both cruciate ligaments of which 107 knees in 89 patients have been followed for ten years. The patients were 34 men and 96 women whose average age, at the time of the index arthroplasty, was 67 years (range: 40 to 84 years). The diagnosis was osteoarthritis in 122 (75%) knees and rheumatoid arthritis in 41 (25%). Twenty-six knees had a valgus deformity, 109 knees a varus deformity and 28 knees had a normal alignment of 5 to 10° of valgus. The anterior cruciate ligament was relatively normal in 96 knees and partly degenerated in 67 knees. Using the Knee Society rating system (37), all 163 knees were prospectively evaluated at yearly intervals including 56 knees in 41 patients who were followed in this manner until they died or were lost to follow-up. 104 knees (97%) of the 107 knees available for study at ten years had excellent or good results. At the latest follow-up in this group of patients, pain was adequately relieved in 97 knees (91%), the average flexion range was 107 ± 12.6° (range: 65 to 135°). Ninety-five knees (89%) had normal antero-posterior stability (less than 5 mm) and 12 knees (11%) had (5 to 10 mm) as determined by the drawer sign. Ninety-six knees (90%) had normal mediolateral stability and 11 knees (10%) had a laxity from 5 to 10°. Ninety-four knees (88%) had a valgus alignment of 5 to 10°. The average knee score was 90.7 ± 8.4 (range: 54 to 100) and the functional score was 82 ± 21 (range: 10 to 100). The survival at ten years with the end point being revision was 94.8% ± 1.95. Seven knees (4.3%) of the 163 knees in this series were revised. There were no revision for patellar problems or aseptic tibial component loosening. The good anteroposterior stability at latest follow-up in this series indicates that both the anterior and posterior cruciate ligaments, even when partly degenerated, remain functional after an average follow-up of ten years.