Mid-term outcomes of primary constrained condylar knee arthroplasty for severe knee deformity / 华中科技大学学报（医学）（英德文版）

This study aimed to examine the clinical and radiographic outcomes of primary total knee arthroplasy (TKA) with use of NexGen® Legacy® Constrained Condylar Knee (CCK) prosthesis for severe knee deformity. Clinical data of 46 patients (48 knees in total, aged 61 years on average) with severe knee deformity who underwent TKA with NexGen® Legacy® CCK prosthesis between December 2007 and February 2012 were retrospectively analyzed. There were 34 knees with severe valgus with incompetent medial collateral ligament, 11 knees with severe flexion contracture with inability to achieve knee balancing in flexion and extension by posterior soft tissue release, 2 knees with Charcot arthritis with severe varus and bone loss, and 1 with traumatic osteoarthritis with severe varus and ligamentous instability. The mean duration of follow-up was 71 months (range 40-90 months). The New Knee Society scoring (NKSS) system and the Hospital for Special Surgery (HSS) score were used to evaluate the functional and clinical outcomes. Visual Analogue Scale (VAS) was used for pain measurement and Knee Society criteria for evaluation of radiological images. The results showed that, in the total 48 knees, 1 case of loosening due to short-stem tibial component at 3 months post-operatively underwent revision. The 6-year prosthesis survival rate in this cohort was 97.9%. There was no component infection occurring within 6 years. Significant post-operative improvements were found in NKSS and HSS scores. Patient satisfaction was significantly increased. Pain score was decreased significantly. Total functional score was improved from 31.46±11.43 to 86.42±8.87, range of motion (ROM) from 42.42°±23.57° to 95.31°±23.45° and the flexion contracture from 5.31°±7.87° to 0.92°±1.80°. Preoperative radiographic study showed excessive valgus (≥7°) in 37 knees, and varus deformity in 3 knees. Post-operative femorotibial alignment was valgus 3.88°±1.76° in 48 knees. Antero/posterior (A/P) view of X-ray films showed 4 radiolucent lines (RLL) in 48 tibial components. It was concluded that TKA with CCK is effective for the treatment of the severe unstable knee that cannot be balanced by soft tissue.

A Comparative Study of Subcutaneous versus Intra-Articular Indwelling Closed Suction Drainage after Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: The aim of this study was to compare the drainage amount, total blood loss, and clinical results between two different positions of suction drainage after total knee arthroplasty. MATERIALS AND METHODS: A total of 100 patients who underwent one stage bilateral total knee arthroplasty were enrolled. In experiment 1 with 50 patients, we compared the drainage amount, pain, range of motion, and complications of the leg whose suction drain was inserted into the joint cavity with those of the contralateral leg whose suction drain was inserted in subcutaneous tissue. Another 50 patients of experiment 2 had suction drainage in the joint cavity of both legs and the total blood loss (sum of drainage output, exudates, and hematoma of subcutaneous tissue and joint) was calculated and compared with that of experiment 1. RESULTS: In experiment 1, the drainage amount was less in the leg with suction drainage in subcutaneous tissue compared with the contralateral leg with suction drainage in the joint cavity (p<0.001). However, the postoperative joint pain was significantly different only on post-operative day 2 between two legs. In experiment 2, there was no significant difference in the total blood loss between the two groups. CONCLUSION: Although the drainage amount was less in the leg whose suction drain was kept in subcutaneous tissue compared with the contralateral leg whose suction drain was in the joint cavity, the total blood loss and the clinical results were not significantly different according to the position of the suction drain. Therefore, we can conclude that the subcutaneous position of the suction drain did not yield superior results.