Mid-Term Results of Oxford Medial Unicompartmental Knee Arthroplasty

BACKGROUND: This study examined the clinical and radiologic mid-term results of patients treated by Oxford minimally invasive unicompartmental knee arthroplasty. METHODS: One hundred and eighty-eight knees of unicompartmental knee arthroplasties with Oxford Uni(R) in 166 patients (16 males and 150 females), which were performed between 2002 and 2005, were reviewed. The mean age was 65.3 years (range, 44 to 82 years) and the mean follow-up period was 79.8 months (range, 56 to 103 months). The preoperative diagnosis was osteoarthritis in 166 patients, osteonecrosis of the medial femoral condyle in 20 and chondrocalcinosis in 2. RESULTS: The mean Hospital for Special Surgery (HSS) knee score was 67.5 (range, 52 to 75) preoperatively and 89.9 (range, 85 to 100) at the final follow-up. The mean preoperative flexion contracture was 6.5degrees (range, 0 to 15degrees) and 0.8degrees (range, 0 to 5degrees) at the final follow-up. The mean full flexion increased from 135degrees (range, 90 to 150degrees) preoperatively to 150degrees (range, 140 to 165degrees) at the final follow-up. Active full flexion was possible within 2 postoperative months. The squatting and cross-leg postures were possible in 133 patients (80.1%) and 152 patients (91.6%) at the final follow-up. The mean tibiofemoral angle was improved from varus 1.5degrees to valgus 4.8degrees. Complications were encountered in 18 cases (9.5%). A bearing dislocation occurred in 10 cases (5.3%), tibial component loosening in 4 cases (2.1%), femoral loosening in 3 cases (1.6%) and lateral translation in 1 case (0.5%). The mean time for a bearing dislocation was 22.6 months (range, 3 to 70 months) postoperatively. Seven cases returned to the predislocation level of activity with the insertion of a thicker bearing and 3 cases converted to total knee arthroplasty. CONCLUSIONS: Minimally invasive unicompartmental knee arthroplasty with Oxford Uni(R) provided rapid recovery, good pain relief and excellent function suitable for the Korean lifestyle. In contrast, the high complication rates of Oxford Uni(R) encountered in the mid-term results suggested less reliability than total knee arthroplasty.

Ceramic on Ceramic Cementless Total Hip Arthroplasty Using a Large Diameter Head / 대한정형외과학회잡지

PURPOSE: The authors evaluated the clinical and radiological results of ceramic on ceramic articulation cementless total hip arthroplasty using a large diameter head. MATERIALS AND METHODS: Seventy-two hips were followed for more than 2 years after ceramic on ceramic articulation cementless total hip arthroplasty using a 36 mm diameter head. The mean patient age was 62 years (range: 50-85), and the mean follow-up period was 35.3 months (range: 25-53). The Harris hip score, the postoperative inguinal pain and the thigh pain were analyzed clinically. The radiological results were assessed using various radiological indices. RESULTS: The mean Harris hip score improved from preoperative 57.5 points to postoperative 94.8 points. The postoperative mean flexion of hip was 109degrees (range: 100degrees-125degrees), external rotation was 42degrees (range: 35degrees-49degrees) and abduction was 35degrees (range: 30degrees-45degrees). There was one case of inguinal pain. Radiologically, all the stems demonstrated stable fixation without progressive subsidence of the stem or significant change in the cup obliquity. A radiolucent line was observed around the stem in 4 cases (5.6%) and around the cup in 2 cases (2.8%). Endosteal new bone formation was observed around the stem in 28 cases (38.9%) and around the cup in 26 cases (36.1%). There was no osteolysis around the stem or the cup. CONCLUSION: The short-term results of ceramic on ceramic cementless total hip arthroplasty using a large diameter head demonstrated satisfactory results.