Curtin Brian, Fehring Thomas K, Lauber Jessica
Orthopedics. 2014 Jul;37(7):e644-8. doi: 10.3928/01477447-20140626-56.
This study describes the variance within a representative population of total knee arthroplasty (TKA) patients to provide guidance in improving coronal alignment. The authors retrospectively reviewed 250 preoperative full-length standing radiographs in a consecutive series of TKAs performed by one surgeon. The distal femoral resection was templated on each radiograph to establish a femoral mechanical anatomical (FMA) angle to guide resection. Mean FMA angle was 5.35°, with a wide variation in FMA angle ranging from 1° to 10°. Slightly more than half (56%) of patients had either a 5° or 6° FMA angle, which is concerning for surgeons using a fixed resection angle. Ninety percent of patients measured within the 5°±2° window. Similarly, 90.7% of patients measured within the 6°±2° window. However, nearly 10% of patients (9.75%) had measurements greater than 7° or less than 3°. This study reports a wide variance in the angle of resection required to establish proper femoral mechanical alignment in TKA. Surgeons should be cognizant of the numerous variables that play a role in TKA and influence overall coronal alignment. Many of these variables can be fully assessed by evaluating full-length standing leg radiographs preoperatively. With experience, templating long-leg films can be reproducible and informative in preparing for each surgical procedure. Routine reliance on a single fixed resection angle could result in malalignment in 10% of patients.
本研究描述了全膝关节置换术（TKA）患者代表性人群中的差异，以指导改善冠状面排列。作者回顾性分析了由一位外科医生连续进行的一系列TKA手术中250例术前全长站立位X线片。在每张X线片上对股骨远端切除术进行模板化，以确定股骨机械解剖（FMA）角来指导切除。平均FMA角为5.35°，FMA角变化范围很广，从1°到10°。略超过一半（56%）的患者FMA角为5°或6°，这对于使用固定切除角度的外科医生来说是个问题。90%的患者测量值在5°±2°范围内。同样，90.7%的患者测量值在6°±2°范围内。然而，近10%的患者（9.75%）测量值大于7°或小于3°。本研究报告了在TKA中建立正确股骨机械对线所需的切除角度存在很大差异。外科医生应认识到在TKA中起作用并影响整体冠状面排列的众多变量。通过术前评估全长站立位腿部X线片可以充分评估其中许多变量。凭借经验，在为每次手术做准备时，对长腿X线片进行模板化可以具有可重复性并提供有用信息。常规依赖单一固定切除角度可能导致10%的患者出现对线不良。
