BACKGROUND Many authors and the data of multiple registries have suggested that the use of posterior cruciate-substituting (posterior stabilized [PS]) total knee arthroplasty (TKA) leads to a higher risk of revision compared with the use of posterior cruciate-retaining (CR) TKA. The aim of the present prospective, randomized, long-term study was to compare PS and CR TKA with regard to the clinical, radiographic, and computed tomography (CT) results; the prevalence of osteolysis; revision rate; and survivorship. METHODS This study included a consecutive series of 300 patients (mean age [and standard deviation], 63.6 ± 6 years) who underwent simultaneous, bilateral TKA in the same anesthetic session. Each patient received a NexGen CR-Flex prosthesis on 1 side and a NexGen LPS-Flex prosthesis on the contralateral side. The mean follow-up period was 18 years (range, 17.5 to 19.5 years). RESULTS There were no significant differences between the NexGen CR and LPS-Flex TKA groups at the latest follow-up with regard to the mean Knee Society knee score (93 versus 92 points, respectively); the Western Ontario and McMaster Universities Osteoarthritis Index score (19.1 points for both); the University of California Los Angeles activity score (6.1 points for both); range of motion (125° ± 6.1° versus 126° ± 6.5°); radiographic and CT results; and revision rate (6.0% versus 6.3%). No knee had osteolysis. The estimated survival rate at 19.5 years was 94% (95% confidence interval [CI], 91% to 100%) for the NexGen CR-Flex prosthesis and 93.7% (95% CI, 91% to 100%) for the LPS-Flex prosthesis, with revision or aseptic loosening as the end point. CONCLUSIONS The findings of the present, long-term (minimum follow-up of 17.5 years) clinical study showed that NexGen CR-Flex and NexGen LPS-Flex implants produced excellent clinical and radiographic results. There was no notable clinical advantage of a NexGen CR-Flex implant over a NexGen LPS-Flex implant. LEVEL OF EVIDENCE Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

中文翻译：

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后交叉骨保留和后交叉骨替代 TKA 之间的翻修率或存活率没有明显差异。


背景 许多作者和多个登记处的数据表明，与使用后交叉骨保留 （CR） TKA 相比，使用后交叉骨替代 （后交叉骨 [PS]）全膝关节置换术 （TKA） 会导致更高的翻修风险。本前瞻性、随机、长期研究的目的是比较 PS 和 CR TKA 与临床、影像学和计算机断层扫描 （CT） 结果;骨溶解的患病率;修订率;和幸存者。方法 本研究包括 300 名患者 （平均年龄 [和标准差]，63.6 ± 6 岁）的连续系列，他们在同一麻醉疗程中同时接受了双侧 TKA。每位患者在 1 侧接受 NexGen CR-Flex 假体，在对侧接受 NexGen LPS-Flex 假体。平均随访期为 18 年 （范围，17.5 至 19.5 年）。结果 在最近的随访中，NexGen CR 和 LPS-Flex TKA 组在平均膝关节协会膝关节评分方面没有显著差异（分别为 93 分和 92 分）;西安大略大学和麦克马斯特大学骨关节炎指数评分（两者均为 19.1 分）;加州大学洛杉矶分校活动得分（两者均为 6.1 分）;活动范围（125° ± 6.1° 对比 126° ± 6.5°）;放射学和 CT 结果;和翻修率 （6.0% 对 6.3%）。没有膝关节有骨质溶解。NexGen CR-Flex 假体的 19.5 年估计生存率为 94% （95% 置信区间 [CI]，91% 至 100%），LPS-Flex 假体为 93.7% （95% CI，91% 至 100%），以翻修或无菌松动为终点。结论 目前的、长期的（至少随访 17 次。5 年）临床研究表明，NexGen CR-Flex 和 NexGen LPS-Flex 植入物产生了出色的临床和影像学结果。与 NexGen LPS-Flex 种植体相比，NexGen CR-Flex 种植体没有明显的临床优势。证据级别 治疗级别 II .有关证据级别的完整描述，请参阅作者说明。