Zuiderbaan H A, Khamaisy S, Thein R, Nawabi D H, Pearle A D
Computer Assisted Surgery Center, Department of Orthopaedic Surgery, Hospital for Special Surgery, 535 East 70th Street, New York, New York, 10021, USA.
Bone Joint J. 2015 Jan;97-B(1):50-5. doi: 10.1302/0301-620X.97B1.33057.
Progressive degenerative changes in the medial compartment of the knee following lateral unicompartmental arthroplasty (UKA) remains a leading indication for revision surgery. The purpose of this study is to evaluate changes in the congruence and joint space width (JSW) of the medial compartment following lateral UKA. The congruence of the medial compartment of 53 knees (24 men, 23 women, mean age 13.1 years; sd 62.1) following lateral UKA was evaluated pre-operatively and six weeks post-operatively, and compared with 41 normal knees (26 men, 15 women, mean age 33.7 years; sd 6.4), using an Interactive closest point algorithm which calculated the congruence index (CI) by performing a rigid transformation that best aligns the digitised tibial and femoral surfaces. Inner, middle and outer JSWs were measured by sub-dividing the medial compartment into four quarters on pre- and post-operative, weight bearing tunnel view radiographs. The mean CI of knees following lateral UKA significantly improved from 0.92 (sd 0.06) pre-operatively to 0.96 (sd 0.02) (p < 0.001) six weeks post-operatively. The mean CI of the healthy control group was 0.99 sd 0.01. Post-operatively, the mean inner JSW increased (p = 0.006) and the outer decreased (p = 0.002). The JSW was restored post-operatively as no significant differences were noted in all three locations compared with the control group (inner JSW p = 0.43; middle JSW p = 0.019, outer JSW p = 0.51). Our data suggest that a well conducted lateral UKA may improve the congruence and normalise the JSW of the medial compartment, potentially preventing progression of degenerative change.
外侧单髁置换术（UKA）后膝关节内侧间室的进行性退行性改变仍然是翻修手术的主要指征。本研究的目的是评估外侧UKA后内侧间室的匹配度和关节间隙宽度（JSW）的变化。对53例膝关节（24例男性，23例女性，平均年龄13.1岁；标准差62.1）在外侧UKA术前和术后6周进行内侧间室匹配度评估，并与41例正常膝关节（26例男性，15例女性，平均年龄33.7岁；标准差6.4）进行比较，采用交互式最近点算法，通过执行使数字化胫骨和股骨表面最佳对齐的刚体变换来计算匹配指数（CI）。通过在术前和术后负重隧道位X线片上将内侧间室分为四个区域来测量内侧、中间和外侧JSW。外侧UKA术后膝关节的平均CI从术前的0.92（标准差0.06）显著提高到术后6周的0.96（标准差0.02）（p<0.001）。健康对照组的平均CI为0.99±0.01。术后，内侧平均JSW增加（p = 0.006），外侧减小（p = 0.002）。术后JSW恢复正常，与对照组相比，所有三个位置均无显著差异（内侧JSW p = 0.43；中间JSW p = 0.019，外侧JSW p = 0.51）。我们的数据表明，实施良好的外侧UKA可能会改善内侧间室的匹配度并使JSW正常化，从而有可能防止退行性改变的进展。
