1Knee Research Australia, Gold Coast, Queensland, Australia 2Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia 3Australian Orthopaedic Association National Joint Replacement Registry, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.
J Bone Joint Surg Am. 2017 Jul 5;99(13):1129-1139. doi: 10.2106/JBJS.16.01083.
Controversy still exists as to the optimum management of the posterior cruciate ligament (PCL) in total knee arthroplasty. Surgeons can choose to kinematically substitute the PCL with a posterior-stabilized total knee replacement or alternatively to utilize a cruciate-retaining, also known as minimally stabilized, total knee replacement. Proponents of posterior-stabilized total knee replacement propose that the reported lower survivorship in registries when directly compared with minimally stabilized total knee replacement is due to confounders such as selection bias because of the preferential usage of posterior-stabilized total knee replacement in more complex or severe cases. In this study, we aimed to eliminate these possible confounders by performing an instrumental variable analysis based on surgeon preference to choose either posterior-stabilized or minimally stabilized total knee replacement, rather than the actual prosthesis received.
Cumulative percent revision, hazard ratio (HR), and revision diagnosis data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry from September 1, 1999, to December 31, 2014, for 2 cohorts of patients, those treated by high-volume surgeons who preferred minimally stabilized replacements and those treated by high-volume surgeons who preferred posterior-stabilized replacements. All patients had a diagnosis of osteoarthritis and underwent fixed-bearing total knee replacement with patellar resurfacing.
At 13 years, the cumulative percent revision was 5.0% (95% confidence interval [CI], 4.0% to 6.2%) for the surgeons who preferred the minimally stabilized replacements compared with 6.0% (95% CI, 4.2% to 8.5%) for the surgeons who preferred the posterior-stabilized replacements. The revision risk for the surgeons who preferred posterior-stabilized replacements was significantly higher for all causes (HR = 1.45 [95% CI, 1.30 to 1.63]; p < 0.001), for loosening or lysis (HR = 1.93 [95% CI, 1.58 to 2.37]; p < 0.001), and for infection (HR = 1.51 [95% CI, 1.25 to 1.82]; p < 0.001). This finding was irrespective of patient age and was evident with cemented fixation and with both cross-linked polyethylene and non-cross-linked polyethylene. However, the higher revision risk was only evident in male patients.
There was a 45% higher risk of revision for the patients of surgeons who preferred a posterior-stabilized total knee replacement compared with the patients of surgeons who preferred a minimally stabilized total knee replacement.
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
在全膝关节置换术中，对于后交叉韧带（PCL）的最佳处理方式仍存在争议。外科医生可以选择通过后稳定型全膝关节置换来运动替代 PCL，或者选择使用保留交叉韧带的，也称为最小稳定型，全膝关节置换。后稳定型全膝关节置换术的支持者提出，与最小稳定型全膝关节置换术直接比较时，在注册研究中报告的较低存活率是由于混杂因素造成的，例如由于更复杂或严重的病例中优先使用后稳定型全膝关节置换术而导致的选择偏倚。在这项研究中，我们旨在通过基于外科医生选择使用后稳定型或最小稳定型全膝关节置换术的倾向而不是实际使用的假体进行工具变量分析，来消除这些可能的混杂因素。
从 1999 年 9 月 1 日至 2014 年 12 月 31 日，我们从澳大利亚矫形协会全国关节置换登记处获得了 2 个队列患者的累积翻修百分比、风险比（HR）和翻修诊断数据，队列 1 为高容量外科医生治疗的患者，他们更喜欢最小稳定型置换，队列 2 为高容量外科医生治疗的患者，他们更喜欢后稳定型置换。所有患者均被诊断为骨关节炎，并接受了带髌骨表面置换的固定轴承全膝关节置换术。
在 13 年时，对于更喜欢最小稳定型置换的外科医生，累积翻修百分比为 5.0%（95%置信区间[CI]，4.0%至 6.2%），而对于更喜欢后稳定型置换的外科医生，累积翻修百分比为 6.0%（95%CI，4.2%至 8.5%）。对于更喜欢后稳定型置换的外科医生，所有原因（HR=1.45[95%CI，1.30 至 1.63]；p<0.001）、松动或溶解（HR=1.93[95%CI，1.58 至 2.37]；p<0.001）和感染（HR=1.51[95%CI，1.25 至 1.82]；p<0.001）的翻修风险均显著更高。这一发现与患者年龄无关，并且在骨水泥固定和交联聚乙烯与非交联聚乙烯中均存在。然而，较高的翻修风险仅在男性患者中明显。
与更喜欢最小稳定型全膝关节置换术的外科医生的患者相比，更喜欢后稳定型全膝关节置换术的外科医生的患者翻修风险高出 45%。
治疗性 III 级。请参阅作者指南，以获取完整的证据水平描述。
