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.

Treatment of Medial Collateral Ligament during Total Knee Arthroplasty:a Short Term Follow-up Study / 中国医科大学学报

Objective To compare the knee function in patients with intraoperative medial collateral ligament(MCL)injury treated with or with?out increased prosthetic constraint. Methods The records of 19 cases who encountered with iatrogenic injury to the MCL during total knee arthro?plasty(TKA)between January 2005 and December 2010 were retrospectively reviewed. Eight patients(LCCK group)were treated with increased prosthetic constraint;the remaining 11 patients(LPS group)received increased prosthetic constraint between January 2005 and December 2010 served as controls. The MCL was repaired after TKA. The complications were observed after operation. Knee society scores(KSS)subjective knee scores were used to assess the knee function. No patient was lost for follow?up. The mean follow?up was 5 years. Results Until last follow?up(60 months),The KSS subjective score was 87.4 for LCCK group compared with 93.3 for the LPS group. No revisions for knee instability were per?formed in the 11 patients treated with non?prosthetic constraint;however,2 patients treated with increased prosthetic constraint were revised due to joint loosening. Conclusion The MCL tear should be repaired during TKA;the type of the prosthesis should not be increased when MCL injury is recognized during TKA.