Itoi E, King G J, Neibur G L, Morrey B F, An K N
Department of Orthopedics, Mayo Clinic.
J Orthop Res. 1994 Sep;12(5):665-71. doi: 10.1002/jor.1100120509.
Malrotation of the humeral component of the capitellocondylar total elbow replacement is thought but not proved to be one of the major causes of postoperative dislocation. The purpose of this study was to quantitate the effect of malrotation of the humeral component on the kinematics and laxity of the capitellocondylar total elbow prosthesis. Eleven fresh previously frozen elbows were used. With the humeral component in optimal position, external rotation, or internal rotation, movements of the elbow with neutral, valgus, and varus loading were monitored with an electromagnetic tracking device. When the humeral component was positioned in external rotation, the ulna was more valgus and supinated than when the component was in optimal position, and when the component was in internal rotation the ulna was more valgus in extension and more supinated in flexion. Malrotation in external rotation decreased valgus-varus laxity, and malrotation in internal rotation increased rotational laxity. Only one elbow became dislocated, despite constant severe maltracking between the components in all of the specimens. We concluded that although malrotation of the humeral component influences the laxity and causes maltracking, it is not the primary cause of postoperative dislocation. The contribution of other factors should be investigated.
肱骨髁间全肘关节置换中肱骨组件的旋转不良被认为是术后脱位的主要原因之一，但尚未得到证实。本研究的目的是量化肱骨组件旋转不良对肱骨髁间全肘关节假体运动学和松弛度的影响。使用了11个新鲜的、先前冷冻的肘关节。将肱骨组件置于最佳位置、外旋或内旋时，用电磁跟踪装置监测肘关节在中立位、外翻和内翻负荷下的运动。当肱骨组件处于外旋位置时，与组件处于最佳位置时相比，尺骨更外翻且旋前；当组件处于内旋位置时，尺骨在伸展时更外翻，在屈曲时更旋前。外旋时的旋转不良降低了外翻-内翻松弛度，内旋时的旋转不良增加了旋转松弛度。尽管所有标本中组件之间持续存在严重的跟踪不良，但只有一个肘关节发生了脱位。我们得出结论，虽然肱骨组件的旋转不良会影响松弛度并导致跟踪不良，但它不是术后脱位的主要原因。应研究其他因素的作用。
