Buechel F F, Pappas M J, Iorio L J
Total Joint Reconstructive and Arthritis Surgery Services, University of Medicine and Dentistry, New Jersey-New Jersey Medical School, Newark.
Foot Ankle. 1988 Jun;8(6):279-90. doi: 10.1177/107110078800800603.
A congruent contact, unconstrained, multiaxial ankle replacement has been developed for use without cement. A talar onlay component with a trochlear surface and central fixation fin uses a cylindrical articulating axis that reproduces the lateral talar curvature. A tibial inlay component with a 7 degree anteriorly inclined short fixation stem uses a flat loading plate, recessed anatomically into the distal tibia to distribute tibial loads to the ankle joint. For both components, made of cast cobalt-chromium-molybdenum, a 275-micron pore-size, sintered-bead, porous coating is used to allow tissue ingrowth stabilization. A congruent ultra-high molecular weight polyethylene bearing is inserted between the metallic implants. Its upper surface is flat, whereas its lower surface conforms to the trochlear surface, thereby providing unconstrained, sliding cylindrical motion with low contact stress on the bearing surfaces. Contact pressure and collateral ligaments maintain ankle stability during both static and dynamic loading conditions. Clinically, 23 total ankle arthroplasties were performed in 21 patients. The follow-up period ranged from 24 months to 64 months with a mean of 35.3 months. Diagnoses included rheumatoid arthritis, 6 patients (26.1%); osteoarthritis, 4 patients (17.4%); post-traumatic arthritis, 10 patients (43.5%); avascular necrosis of the talus, 2 patients (8.7%), and painful ankle fusion, 1 patient (4.3%). Pain was the primary reason for surgery in all cases. Postoperatively, 87% of ankles had no pain or, at most, mild pain. Postoperative complications included poor wound healing in four ankles, reflex sympathetic dystrophy in two ankles, deep infection in one ankle, and one bearing subluxation. No ankle replacements were removed and no fusions were performed for failed implants, although one bearing was exchanged without disrupting the metallic elements. In this report, the suggestion is made that total ankle arthroplasty may have an improved application in various arthritis disorders when used with biologic fixation and unconstrained mobile bearings.
一种无骨水泥使用的贴合、无约束、多轴踝关节置换假体已被研发出来。带有滑车表面和中央固定鳍的距骨覆盖组件采用圆柱形关节轴，该轴再现了距骨外侧曲率。带有7度前倾短固定柄的胫骨嵌入组件采用扁平承载板，其在解剖学上凹陷于胫骨远端，以将胫骨负荷分散至踝关节。对于这两种由铸造钴铬钼制成的组件，使用275微米孔径的烧结珠多孔涂层以实现组织长入稳定。一个贴合的超高分子量聚乙烯轴承插入金属植入物之间。其上表面是平的，而下表面与滑车表面相符，从而在轴承表面提供无约束的滑动圆柱运动且接触应力低。接触压力和侧副韧带在静态和动态加载条件下均维持踝关节稳定性。临床上，对21例患者实施了23例全踝关节置换术。随访期为24个月至64个月，平均35.3个月。诊断包括类风湿性关节炎6例（26.1%）；骨关节炎4例（17.4%）；创伤后关节炎10例（43.5%）；距骨缺血性坏死2例（8.7%），以及疼痛性踝关节融合1例（4.3%）。疼痛是所有病例手术的主要原因。术后，87%的踝关节无疼痛或至多有轻度疼痛。术后并发症包括4例踝关节伤口愈合不良、2例踝关节反射性交感神经营养不良、1例踝关节深部感染和1例轴承半脱位。尽管更换了1个轴承但未破坏金属部件，没有取出任何踝关节置换假体，也没有因植入物失败而进行融合手术。在本报告中，有人提出，当全踝关节置换术与生物固定和无约束活动轴承一起使用时，在各种关节炎疾病中可能有更好的应用。
