King G J, Glauser S J, Westreich A, Morrey B F, An K N
Orthopedic Biomechanics Laboratory, Mayo Clinic/Mayo Foundation, Rochester, Minnesota 55905.
J Arthroplasty. 1993 Jun;8(3):291-8. doi: 10.1016/s0883-5403(06)80092-6.
Total elbow arthroplasty is often used to replace elbow joints that have been severely damaged by arthritis or trauma. A great disparity of designs exists, however, in currently available elbow prostheses. This study evaluated the intrinsic stability of one popular resurfacing implant, the Capitellocondylar (Johnson and Johnson Orthopaedics, Inc., New Brunswick, NJ) total elbow. The in vitro response of this unconstrained prosthesis to valgus-varus and supination-pronation loading was investigated using a materials testing machine. The influence of compressive loading and flexion angle on the intrinsic stability of the prosthesis was studied. The Capitellocondylar prosthesis was found to have little intrinsic constraint, relying on external forces for component stabilization. Dislocations were common at 111 N of compressive loading, while larger loads progressively stabilized the prosthesis. Joint flexion angle had little influence on the intrinsic constraint of the implant except to increase varus stability at lower flexion angles. The Capitellocondylar total elbow prosthesis, as designed by F. C. Ewald, behaves as an unconstrained implant. Adequate soft tissue supports, which are properly balanced to provide controlled loading, are essential to prevent instability of this arthroplasty.
全肘关节置换术常用于替换因关节炎或创伤而严重受损的肘关节。然而，目前市面上的肘关节假体在设计上存在很大差异。本研究评估了一种常用的表面置换植入物——髁间假体（强生骨科公司，新泽西州新不伦瑞克）全肘关节的固有稳定性。使用材料试验机研究了这种非限制性假体对外翻-内翻和旋前-旋后载荷的体外响应。研究了压缩载荷和屈曲角度对假体固有稳定性的影响。发现髁间假体几乎没有固有约束，依靠外力来稳定部件。在111 N的压缩载荷下脱位很常见，而更大的载荷会逐渐稳定假体。除了在较低屈曲角度增加内翻稳定性外，关节屈曲角度对植入物的固有约束影响很小。由F.C.埃瓦尔德设计的髁间全肘关节假体表现为非限制性植入物。适当平衡以提供可控载荷的充足软组织支撑对于防止这种关节成形术的不稳定至关重要。
