Barrack Robert L
Professor of Orthopaedic Surgery and Director, Adult Reconstructive Surgery, Tulane University School of Medicine, New Orleans, LA 70112, USA.
J Am Acad Orthop Surg. 2003 Mar-Apr;11(2):89-99. doi: 10.5435/00124635-200303000-00003.
Implant design and positioning are important factors in maintaining stability and minimizing dislocation after total hip arthroplasty. Although the advent of modular femoral stems and acetabular implants increased the number of head, neck, and liner designs, the features of recent designs can cause intra-articular prosthetic impingement within the arc of motion required for normal daily activities and thus lead to limited motion, increased wear, osteolysis, and subluxation or dislocation. Minimizing impingement involves avoiding skirted heads, matching a 22-mm head with an appropriate acetabular implant, maximizing the head-to-neck ratio, and, when possible, using a chamfered acetabular liner and a trapezoidal, rather than circular, neck cross-section. Computer modeling studies indicate the optimal cup position is 45 degrees to 55 degrees abduction. Angles <55 degrees require anteversion of 10 degrees to 20 degrees of both the stem and cup to minimize the risk of impingement and dislocation.
植入物的设计和定位是全髋关节置换术后维持稳定性和减少脱位的重要因素。尽管模块化股骨柄和髋臼植入物的出现增加了股骨头、颈和内衬的设计数量,但近期设计的特点可能会在正常日常活动所需的运动弧内导致关节内假体撞击,从而导致活动受限、磨损增加、骨质溶解以及半脱位或脱位。尽量减少撞击包括避免使用带裙边的股骨头、将22毫米的股骨头与合适的髋臼植入物相匹配、最大化头颈比,并且在可能的情况下,使用带倒角的髋臼内衬以及梯形而非圆形的颈部横截面。计算机建模研究表明,最佳髋臼位置是外展45度至55度。角度小于55度时,柄和髋臼均需要10度至20度的前倾角,以尽量降低撞击和脱位的风险。