Factors Affecting the Tibiofemoral Alignment in Minimally Invasive Unicompartmental Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: We analyzed affecting factors associated with the tibiofemoral alignment after minimally invasive unicompartmental knee arthroplasty (UKA) used to treat medial compartmental osteoarthritis of the knee. MATERIALS AND METHODS: From January 2003 to December 2003, 128 UKA were performed in 114 patients with minimally invasive surgery. The revealed tibiofemoral angle, tibial translation, posterior slope and the coronary orientation of the tibial and femoral component were measured using the preoperative and postoperative weight-bearing radiographs. The possible factors associated with the corrective tibiofemoral angle were analyzed statistically. RESULTS: The average corrective angle of the tibiofemoral axis was 5.8 degrees from varus 0.6 degrees preoperatively to valgus 5.2 degrees postoperatively. The average corrective angle of the tibiofemoral axis was 6.1 degrees in the mobile bearing group and 3.6 degrees in the fixed bearing group. There was significantly more corrective tibiofemoral angle postoperatively with a larger varus deformity of the knee preoperatively (p<0.0001). The corrective tibiofemoral angle had an increasing tendency with increasing bearing size but this was not statistically significant. Surgeons, the age of the patients, tibial translation, posterior slope of the tibial component, and coronary orientation of the tibial component and femoral component did not affect the degree of the corrective tibiofemoral angle. CONCLUSION: The average corrective angle of the tibiofemoral axis after minimally invasive UKA was 5.8 degrees. The preoperative tibiofemoral angle and the types of implants affected the postoperative tibiofemoral axis after minimally invasive UKA.

Short-Term Results and Early Complications of Minimally Invasive Unicompartmental Knee Arthroplasty

PURPOSE: To evaluate the short-term postoperative results of minimally invasive Unicompartmental Knee Arthroplasty(UKA) and to analysis the early postoperative complications. MATERIALS AND METHODS: 241 cases of UKA have been performed since January 2002 and followed up for average 27.3 months. Most of cases were medial compartment degenerative arthritis. All operative procedures were performed through minimally invasive technique. Clinical assessments were carried out using the Knee Society Score (KSS) rating system. RESULTS: The average knee score and the knee function score were improved from 55.4 and 55.4 points preoperatively to 89.3 and 84.9 points at final follow up. The average range of knee motion was 128.4 degrees preoperatively and recovered to 133.0 degrees at final follow up. Average preoperative tibiofemoral angle was 0.2 degrees of varus, which changed to 5.5 degrees of valgus at final follow up. Early complications after minimally invasive UKA were seen in 14 cases, 13 of which were occured within the first year. There were 4 polyethylene insert dislocation, 3 periprosthetic fracture, 2 femoral component loosening, 3 MCL injury and 1 infection. We also experienced 2 partial capsular rupture, 1 remained cement fragment in the joint and 1 impingement between osteophyte and stem. Two femoral component loosening and 1 MCL injury were combined with bearing dislocation. CONCLUSION: The short-term postoperative results of minimally invasive UKA were clinically satisfactory for improvement of knee score, function score and in the recovery of knee motion. The complication rate of UKA was relative low, but mostly caused by errors in surgical technique. Accurate surgical technique and enough experience were needed to improve clinical results and reduce the complications. When complications have occurred, better results are expected by more appropriate treatment for the cause of the complications.

Unicompartmental Knee Arthroplasty: A Prospective Analysis and Short-term Results / 대한정형외과학회잡지

PURPOSE: To evaluate the early postoperative results of Unicompartmental Knee Arthroplasty (UKA) based on a prospective analysis and follow up study. MATERIALS AND METHODS: Clinical assessments were carried out using the Knee Society Score (KSS) rating system. The tibiofemoral angle and radiographic changes were measured using weight-bearing X-rays. Prospective assessments were conducted preoperatively, and regularly followed up after the operation. Among the cases of UKA performed since January 2002, 67 were able to be followed up at 3, 6, 12 and 24 months after the operation. RESULTS: For these 67 knees, the average preoperative knee score and the knee function score were 54.6 and 56.3 points, respectively. The knee score was improved to 80.1, 85.4, 86.8 and 89.2 points at 3, 6, 12 and 24 months follow ups, respectively. The knee function score was also improved to 70.4, 76.0, 80.2 and 83.0 points at 3, 6, 12 and 24 months. The average range of knee motion was 127.6 degrees preoperatively, and recovered to 128.6 degrees at 3 months postoperatively. The preoperative tibiofemoral angle was 0.7 degrees of valgus, which changed to 5.7 degrees of valgus at 24 months postoperatively. CONCLUSION: As shown in this prospective study, the early postoperative results of UKA were satisfactory for improvement of knee score, function score and in the recovery of knee motion.

Treatment of Soft Tissue Defect after TKA Using Dorsalis Pedis Flap: A Case Report

Skin and soft tissue defect developed after total knee arthroplasty have important influence on prosthesis survival. Thus an adequate treatment have to be performed according to the size and depth of defect. We report a case of dorsalis pedis flap for treatment of skin and soft tissue defect combined with infection after conversion total knee arthroplasty and its good result with a review of the literature.

High Tibial Osteotomy Fixed with Long-winged Modified Steinmann pin

PURPOSE: To report the clinical and radiological results after high tibial osteotomy that was fixed with a long winged modified Steinmann pin. MATERIALS AND METHODS: Forty knees of twenty patients with genu varum, degenerative or physiologic, underwent high tibial osteotomy using a long-winged modified Steinmann pin and four-week cast immobilization. Mean follow up was 36.0 months(5~67 months). Clinical results were assessed using the Knee society score and radiographic measurements, using Bauer 's method and Insall-Savati ratio. Statistical analyses were performed with the paired samples t-test. RESULTS: The corrected angle was varus 3.2+/-2.7 degrees preoperatively, valgus 7.3+/-2.0 degrees postoperatively(p<0.05), and valgus 6.0+/-1.4 degrees at the latest follow up. According to the Knee society clinical rating system, the knee score was 61.8+/-7.2 preoperatively and 92.8+/-2.8 postoperatively (p<0.05). The function score was 77.8+/-5.8 preoperatively and 89.0+/-6.3 postoperatively(p<0.05). The Insall-Salvati ratio was 1.02+/-0.14 preoperatively and 1.00+/-0.15 at the latest follow up(p=0.018). CONCLUSION: High tibial osteotomy with a long-winged modified Steinmann pin could obtain good correction of angles and clinical results with few complications. And this method was also useful in maintaining the correction angles.