Adulkasem Nath, Rojanasthien Sattaya, Siripocaratana Nattapol, Limmahakhun Sakkadech
Department of Orthopaedic Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
J Orthop Surg (Hong Kong). 2019 May-Aug;27(2):2309499019836286. doi: 10.1177/2309499019836286.
Unicompartmental knee arthroplasty (UKA) in anterior cruciate ligament deficiency (ACLD) has been debated for decades after the development of highly cross-linked polyethylene. This study aims to evaluate the effect of posterior tibial slope on restoring adequate knee stability and flexion after UKA in patients with ACLD. A total of 15 fresh cadaveric knees were divided into three groups: intact ACL, partial ACLD, and complete ACLD. Fixed-bearing UKAs including 3-D-printed tibial inserts with the slopes ranging from 3° to 12° were performed using computer-assisted navigation. Blinded evaluation of knee motion and anterior knee translation with knees flexed 20° and 90° was conducted using KT-arthrometry and stress radiography. A 1° slope increase translated the knees anteriorly by 0.85 mm and 0.76 mm in 20° and 90° of knee flexion for a complete ACLD ( R = 0.7 and 0.8, respectively, p < 0.001) compared to 0.5-0.6 mm for the normal and partial ACLD groups, respectively. Setting a slope of 5-8° of UKA for an intact ACL maintained both the stability and the motion of native knees. No significant changes of knee translation and flexion ability were observed after leveling the slopes at 5-7° and 5-6° for partial and complete ACLD, respectively ( p > 0.05 for all comparisons). In conclusion, UKA in complete ACLD knees is challenging since 1° of slope change nearly doubles the degree of knee translation compared to ACL-intact knees. The optimum posterior tibial slopes for fixed-bearing UKA patients with partial and complete ACLD are 5-7° and 5-6°, respectively.
在高交联聚乙烯出现后的几十年里，前交叉韧带缺损（ACLD）患者的单髁膝关节置换术（UKA）一直存在争议。本研究旨在评估后胫骨坡度对ACLD患者UKA术后恢复足够膝关节稳定性和屈曲的影响。总共15个新鲜尸体膝关节被分为三组：完整前交叉韧带组、部分ACLD组和完全ACLD组。使用计算机辅助导航进行固定平台UKA手术，包括3D打印的胫骨假体，其坡度范围为3°至12°。使用KT关节测量仪和应力放射成像对膝关节在屈曲20°和90°时的运动和膝关节前向平移进行盲法评估。对于完全ACLD组，坡度每增加1°，膝关节在屈曲20°和90°时分别向前平移0.85毫米和0.76毫米（R分别为0.7和0.8，p<0.001），而正常组和部分ACLD组分别为0.5 - 0.6毫米。对于完整前交叉韧带的膝关节，将UKA的坡度设置为5 - 8°可维持天然膝关节的稳定性和运动。对于部分ACLD和完全ACLD，分别将坡度调整为5 - 7°和5 - 6°后未观察到膝关节平移和屈曲能力的显著变化（所有比较p>0.05）。总之，完全ACLD膝关节的UKA具有挑战性，因为与前交叉韧带完整的膝关节相比，坡度每变化1°，膝关节平移程度几乎加倍。对于部分和完全ACLD的固定平台UKA患者，最佳后胫骨坡度分别为5 - 7°和5 - 6°。
