Lew W D, Engebretsen L, Lewis J L, Hunter R E, Kowalczyk C
Department of Orthopaedic Surgery, University of Minnesota, Minneapolis 55455.
J Orthop Res. 1990 Sep;8(5):702-11. doi: 10.1002/jor.1100080512.
The objective of this study was to develop a method for obtaining a controllable and reproducible immediate postoperative mechanical state in a knee with an anterior cruciate ligament (ACL) reconstruction. This method, called the force-setting technique, was demonstrated using a composite graft consisting of the middle third of the patellar tendon with bone blocks (PT) and the ligament augmentation device (LAD). The total graft force was set to match the force in the intact ACL at 30 degrees flexion with the knee under the same standardized external load, while at the same time the load sharing between the biologic and augmentation components was controlled. The total graft force was set to match the ACL force three separate times in each knee, with ratios of load sharing set at the following levels: 50% PT-50% LAD, 25% PT-75% LAD, and 75% PT-25% LAD. ACL, PT, LAD, and collateral forces were measured using buckle transducers, and three-dimensional knee motion was measured using an instrumented spatial linkage as 90 N anteriorly directed tibial loads were applied to eight specimens at 0 degree, 30 degrees, 60 degrees, and 90 degrees flexion with an intact ACL, an excised ACL, and the three load-sharing reconstruction states. The total graft force could be consistently set to within an average of 2% of the intact ACL force at 30 degrees flexion, and load sharing between the graft segments could be set to within an average of 5.1% of the desired ratio at 30 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)
本研究的目的是开发一种方法，以在进行前交叉韧带（ACL）重建的膝关节中获得可控且可重复的术后即刻力学状态。这种方法称为力设定技术，使用由带骨块的髌腱中三分之一（PT）和韧带增强装置（LAD）组成的复合移植物进行了演示。在相同的标准化外部负荷下，将总移植物力设定为与膝关节在30度屈曲时完整ACL中的力相匹配，同时控制生物成分和增强成分之间的负荷分担。在每个膝关节中，将总移植物力设定为三次与ACL力相匹配，负荷分担比例设定为以下水平：50%PT - 50%LAD、25%PT - 75%LAD和75%PT - 25%LAD。使用扣式换能器测量ACL、PT、LAD和侧副韧带的力，并使用仪器化空间连杆测量三维膝关节运动，在完整ACL、切除ACL以及三种负荷分担重建状态下，对八个标本在0度、30度、60度和90度屈曲时施加90 N向前的胫骨负荷。总移植物力可以始终如一地设定为在30度屈曲时与完整ACL力的平均值相差2%以内，并且移植物段之间的负荷分担可以设定为在30度时与所需比例的平均值相差5.1%以内。（摘要截短为250字）
