Moussa Mohamed E, Lee Yuo-Yu, Patel Anay R, Westrich Geoffrey H
Division of Adult Reconstruction and Joint Replacement Surgery, Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York.
Epidemiology and Biostatistics Core, Hospital for Special Surgery, New York, New York.
J Arthroplasty. 2017 Jun;32(6):1869-1873. doi: 10.1016/j.arth.2017.01.001. Epub 2017 Jan 11.
Certain clinical or adverse intraoperative situations require the use of increased constraint in primary total knee arthroplasty (TKA). These include significant angular deformities causing incompetent collateral ligaments, or inadvertent intraoperative injury to collateral structures as well as the inability to achieve a balanced flexion and extension gap. Clinical success has been described with the use of constrained condylar knee arthroplasty in the primary setting in these situations. Traditionally, increasing constraint has been in conjunction with intramedullary stems, referred to as stemmed constrained condylar knees (SCCK); however, some devices provide an intermediary option by increasing constraint without the use of stems, herein referred to as nonstemmed constrained condylar knees (NSCCK). The aim of this study was to compare the clinical outcomes of both these devices in primary TKA in terms of revision rates and change in outcome measures over the follow-up period.
Between 2007 and 2012, 85 SCCKs and 354 NSCCKs were identified in our institutional registry database performed in the primary TKA setting with minimum 2-year clinical outcome measure follow-up. Baseline demographic information, as well as Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Lower Extremity Activity Scale (LEAS) were collected preoperatively at 2-year follow-up. Revision data were also collected.
Both groups showed substantial improvement in WOMAC scores (pain, stiffness, and function), and LEAS at 2 years postoperatively compared with baseline, although the changes in scores were not statistically significant. One of 85 SCCKs (1.17%) was revised for infection, whereas 9 of 354 NSCCKs (2.54%) were revised (6 for mechanical complications, eg, loosening, 2 for periprosthetic fracture, and 1 for infection).
Both cohorts demonstrated improvement in clinical outcome measures at 2-year follow-up. None of the SCCKs performed in the primary setting were revised for a mechanical complication. Although both groups had overall low revision rates, there was trend toward a higher revision rate with NSCCKs. Many of these were revised for component loosening. In summary, when necessary, constrained options in the primary TKA setting provide excellent clinical outcome at short-term follow-up. However, constrained constructs with stemmed fixation may provide more rigid fixation and be less susceptible to mechanical failure.
在初次全膝关节置换术（TKA）中，某些临床情况或术中不良情况需要增加固定限制。这些情况包括导致侧副韧带功能不全的严重角度畸形、术中意外损伤侧副结构以及无法实现屈伸间隙平衡。在这些情况下，在初次手术中使用限制性髁膝关节置换术已取得临床成功。传统上，增加固定限制是通过髓内柄实现的，称为带柄限制性髁膝关节（SCCK）；然而，一些装置通过不使用柄增加固定限制提供了一种中间选择，在此称为无柄限制性髁膝关节（NSCCK）。本研究的目的是比较这两种装置在初次TKA中的临床结果，包括翻修率以及随访期间结果指标的变化。
在2007年至2012年期间，在我们机构的登记数据库中识别出85例SCCK和354例NSCCK，这些病例均为初次TKA手术，且至少有2年的临床结果指标随访。术前收集基线人口统计学信息以及西安大略和麦克马斯特大学关节炎指数（WOMAC）和下肢活动量表（LEAS），并在2年随访时再次收集。同时收集翻修数据。
与基线相比，两组在术后2年时WOMAC评分（疼痛、僵硬和功能）以及LEAS均有显著改善，尽管评分变化无统计学意义。85例SCCK中有1例（1.17%）因感染进行了翻修，而354例NSCCK中有9例（2.54%）进行了翻修（6例因机械并发症，如松动；2例因假体周围骨折；1例因感染）。
两组在2年随访时临床结果指标均有改善。初次手术中进行的SCCK均未因机械并发症进行翻修。虽然两组总体翻修率较低，但NSCCK有翻修率较高的趋势，其中许多是因假体松动进行翻修。总之，必要时，初次TKA中的限制性选择在短期随访中可提供良好的临床结果。然而，带柄固定的限制性结构可能提供更牢固的固定，且机械故障的易感性更低。
