Abstract
we evaluated 47 total knee arthroplasties with a cementless component in 32 patients, performed from August, 1988 to November, 1992 with 34 Miller/Galante (M/G) type protheses and 13 Omnifit (OM) type. The mean age at operation was 67.8 (range, 50-80) . Twenty-two knees were in 16 patients with osteoarthritis (OA), 24 knees in 15 patients with rheumatoid arthritis (RA), and 1 knee had osteonecrosis of the femoral medial condyle. The mean follow-up period was 29.9 months (range, 6.8-57.8) . The knee scores using the Three University Plan knee scoring system improved from an average of 47.4 preoperatively to 87.4 in OA patients and from 38.6 to 78.1 in RA patients. The mean FTA and ROM at follow-up were 176.3 degrees and 104.9 degrees/-2.9 degrees (flexion/ extension) in OA patients, and 173.6 and 102.9/ - 3.3 degrees in RA patients, respectively. Using radiographic findings we evaluated the risk factors of fixation failure between bone and components. Clear zones of bone-component interfaces were revealed in 48.9% of all cases. In 2 cases of RA these were over 2mm in width. Eight knees with OM type components had clear zones with displaced beads, which had the risk of migrating into the joint surface. One case with RA showed massive bone atrophy near the femoral and tibial components. Sinking of tibial components was revealed in 36.2% of all cases, 82.3% of which were thought to be caused by either malpositioning of tibial components and/or the use of smaller size tibial components.
