Buechel F F, Pappas M J
Total Joint Reconstructive Services, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark.
Orthop Clin North Am. 1989 Apr;20(2):147-77.
A metal-backed, interchangeable, meniscal bearing knee replacement system has been designed to combine low constraint forces with low contact stresses (LCS) to allow nearly normal joint articulation and loading as well as long-term wear resistance of the implants. System components allow unicompartmental, bicompartmental, tricompartmental, and revision knee arthroplasties. In this prospective comparison study, the early series of cases used methyl methacrylate for prosthesis-to-bone fixation, whereas the more recent series of knee replacements used sintered-bead porous coating to allow tissue ingrowth stabilization of all implants. Overall results in the first 149 cemented cases with 2- to 10-year follow-up (mean 7.6 years) were good to excellent in 85.2 per cent, fair in 3.4 per cent, and poor in 11.4 per cent using a strict knee scoring scale. Fair and poor results were seen predominantly in multiply operated and implant revision cases. The best cemented results were noted in primary cases, 95.1 per cent of which had good to excellent results. Overall results in the first 208 cementless cases with 2- to 7-year follow-up (mean 4.4 years) were good to excellent in 91.8 per cent, fair in 2.4 per cent, and poor in 5.8 per cent. Fair and poor results were also seen predominantly in multiply operated and implant revision cases. The best cementless results were noted in primary cases, 98.2 per cent of which had good to excellent results. Of 140 meniscal bearing implants in the entire series, one dislocation occurred (0.7 per cent) which required open bearing replacement. Of 217 rotating platform bearing implants in the entire series, 7 dislocations occurred (3.2 per cent), which required open bearing replacement or revision of components for malposition. These dislocations were seen predominantly in revision cases involving insufficient flexion stability; 6 of the 7 cases were revisions. This study demonstrates the efficacy of mobile bearing elements for use in knee replacement arthroplasty. It is essential that flexion and extension gaps be controlled to maintain contact pressure on such bearings to avoid problems of subluxation or dislocation.
一种金属背衬、可互换的半月板轴承膝关节置换系统被设计成将低约束力与低接触应力（LCS）相结合，以实现近乎正常的关节活动和负荷，以及植入物的长期耐磨性。系统组件可用于单髁、双髁、三髁和翻修膝关节置换术。在这项前瞻性比较研究中，早期的一系列病例使用甲基丙烯酸甲酯进行假体与骨的固定，而最近的一系列膝关节置换术则使用烧结珠多孔涂层，以使所有植入物通过组织长入实现稳定。对最初149例采用骨水泥固定的病例进行2至10年随访（平均7.6年），按照严格的膝关节评分标准，结果为优至良的占85.2%，一般的占3.4%，差的占11.4%。一般和差的结果主要出现在多次手术和植入物翻修的病例中。骨水泥固定的最佳结果出现在初次手术病例中，其中95.1%的病例结果为优至良。对最初208例非骨水泥固定的病例进行2至7年随访（平均4.4年），结果为优至良的占91.8%，一般的占2.4%，差的占5.8%。一般和差的结果也主要出现在多次手术和植入物翻修的病例中。非骨水泥固定的最佳结果出现在初次手术病例中；其中98.2%的病例结果为优至良。在整个系列中的140个半月板轴承植入物中，发生了1例脱位（0.7%），需要进行开放式轴承置换。在整个系列中的217个旋转平台轴承植入物中，发生了7例脱位（3.2%），需要进行开放式轴承置换或因位置不当而对组件进行翻修。这些脱位主要出现在涉及屈曲稳定性不足的翻修病例中；7例中有6例是翻修病例。本研究证明了活动轴承元件在膝关节置换术中的有效性。必须控制屈伸间隙，以保持此类轴承上的接触压力，避免半脱位或脱位问题。
