Lonner Jess H
Department of Orthopedic Surgery, Pennyslvania Hospital, Philadelphia, Pennsylvania, USA.
Orthopedics. 2010 Sep 7;33(9):653. doi: 10.3928/01477447-20100722-39.
Isolated patellofemoral arthritis can occur in as many as 9% of patients older than 40 years and is particularly common in women, who often have subtle patellofemoral maltracking or malalignment. In fact, 24% of women with symptomatic knee arthritis have localized patellofemoral arthritis. Arthroplasty options can provide predictable pain relief, whereas other surgical measures for refractory patellofemoral arthritis--arthroscopic debridement, cartilage grafting, patellectomy, tibial tubercle unloading procedures--often have unsatisfactory results. While total knee arthroplasty (TKA) yields excellent results in >90% of patients with isolated patellofemoral arthritis, it is not desirable in patients who are young and active. Therefore, patellofemoral arthroplasty has a legitimate role in the treatment of isolated anterior compartment arthritis. Early patellofemoral implants were plagued by a high incidence of patellar maltracking, catching and subluxation, due to design features of the trochlear components, inadequate soft tissue balancing, and component malposition. Most importantly, contemporary onlay style trochlear components, implanted perpendicular to the anteroposterior axis of the femur, have substantially reduced the patellar maltracking that was so prevalent with inlay style prostheses for 3 decades. With onlay trochlear designs, early patella instability problems have been reduced, leaving late tibiofemoral degeneration as the primary cause of failure of patellofemoral arthroplasties. Several long-term studies have shown a rate of tibiofemoral degeneration of approximately 20% at 15 years. Finally, the results of TKA do not seem to be compromised by the presence of a prior patellofemoral arthroplasty.
孤立性髌股关节炎在40岁以上患者中发生率高达9%，在女性中尤为常见，她们常存在细微的髌股轨迹不良或对线不良。事实上，24%有症状的膝关节关节炎女性患有局限性髌股关节炎。关节成形术可提供可预测的疼痛缓解，而针对难治性髌股关节炎的其他手术措施——关节镜清理、软骨移植、髌骨切除术、胫骨结节卸载手术——往往效果不佳。虽然全膝关节置换术（TKA）在90%以上的孤立性髌股关节炎患者中取得了优异的效果，但对于年轻且活跃的患者并不理想。因此，髌股关节置换术在孤立性前侧间室关节炎的治疗中具有合理的作用。早期的髌股植入物因滑车部件的设计特点、软组织平衡不足和部件位置不当，髌股轨迹不良、卡顿和半脱位的发生率很高。最重要的是，当代的覆盖式滑车部件垂直于股骨的前后轴植入，大大减少了过去30年中镶嵌式假体普遍存在的髌股轨迹不良。采用覆盖式滑车设计，早期髌骨不稳定问题已减少，晚期胫股关节退变成为髌股关节置换失败的主要原因。几项长期研究表明，15年时胫股关节退变率约为20%。最后，先前进行过髌股关节置换术似乎并未影响TKA的效果。
