Kabo J M, Yang R S, Dorey F J, Eckardt J J
Department of Orthopaedic Surgery, University of California, Los Angeles, School of Medicine 90095-6902, USA.
Clin Orthop Relat Res. 1997 Mar(336):166-76. doi: 10.1097/00003086-199703000-00024.
The in vivo rotary laxity and torsional stiffness of the knee joint were measured in 20 patients with wide intraarticular resection of the distal femoral tumor followed by reconstruction with a custom Kinematic rotating hinge endoprosthesis. The contralateral normal knee served as natural control. Twenty patients underwent 29 measurements, including 9 at the first year, 10 at the second year (4 of these also measured at year 1), and 10 at the third year (3 of these also measured at years 1 and 2; 2 also measured at year 2). The mean followup for the 15 survivors was 134 months (range, 102-156 months). The total rotatory laxity of the hinged knee was significantly greater than that of the contralateral knee. The torsional stiffness in external rotation of the hinged knee was 30.4% less than that of the contralateral knee in the first postoperative year, whereas the torsional stiffness in internal rotation was similar to that of the contralateral knee. Torsional stiffness of the hinged knee in the second year was significantly less than that of the contralateral knee whereas it was within the normal range of stiffness in the third year. The total rotatory laxity and torsional stiffness of the hinged knee in the early postoperative years could not predict the risk of late loosening. In vitro rotational stability of the rotating hinge device with axial load bearing was 6.7 and 8.1 Newton-meters (N-m) at 0 degrees and 20 degrees knee flexion, respectively, under an axial tibial load of 945 Newtons.
对20例股骨远端肿瘤行关节内广泛切除并采用定制的运动旋转铰链型人工关节重建的患者，测量其膝关节的体内旋转松弛度和扭转刚度。对侧正常膝关节作为自然对照。20例患者共进行了29次测量，其中第1年9次，第2年10次（其中4次在第1年也进行了测量），第3年10次（其中3次在第1年和第2年也进行了测量；2次在第2年也进行了测量）。15例存活患者的平均随访时间为134个月（范围102 - 156个月）。铰链式膝关节的总旋转松弛度显著大于对侧膝关节。术后第1年，铰链式膝关节外旋时的扭转刚度比对侧膝关节低30.4%，而内旋时的扭转刚度与对侧膝关节相似。铰链式膝关节在第2年的扭转刚度显著低于对侧膝关节，而在第3年则在正常刚度范围内。术后早期铰链式膝关节的总旋转松弛度和扭转刚度不能预测晚期松动的风险。在945牛顿的轴向胫骨载荷下，带轴向承重的旋转铰链装置在膝关节屈曲0度和20度时的体外旋转稳定性分别为6.7和8.1牛顿·米（N-m）。
