Department of Orthopedic Surgery, Korea University College of Medicine, Korea University Guro Hospital, Seoul, Republic of Korea.
Department of Orthopedic Surgery, Korea University College of Medicine, Korea University Ansan Hospital, Ansan, Gyeonggi-do, Republic of Korea.
J Arthroplasty. 2020 Jan;35(1):265-271. doi: 10.1016/j.arth.2019.08.004. Epub 2019 Aug 8.
This study investigated the epidemiology and causes of bearing dislocations following mobile-bearing unicompartmental knee arthroplasty (MUKA) and determined whether the incidence of primary bearing dislocations decreases as surgeon experience increases.
We retrospectively reviewed the bearing dislocations following MUKAs performed by 14 surgeons with variable experience levels. Causes of bearing dislocations were determined based on the surgical records, radiographs, and operator's suggestion. Using a chi-squared test, the incidence of bearing dislocation was compared between the first 50, the second 50, and the next 100 unicompartmental knee arthroplasties (UKAs) of each surgeon's cohort.
There were 67 (3.6%) bearing dislocations from 1853 MUKAs. The mean time to bearing dislocations after index MUKAs was 33 months (range, 1-144 months); 55% of the bearing dislocations occurred within 2 years after the index MUKAs. Primary bearing dislocations (n = 58) were the most common, followed by secondary (n = 6) and traumatic dislocations (n = 3). There was no significant difference in the incidence of bearing dislocation between the first 50 and second 50 UKAs for each surgeon. Two surgeons showed a significant decrease in bearing dislocations in their second 100 UKAs, while the other surgeons did not show a difference between their first 100 and second 100 UKAs.
Most bearing dislocations after MUKAs were related to technical errors such as component malposition or gap imbalance. This study did not confirm that the incidence of bearing dislocations decreases as the number of cases increases.
IV, Case series.
本研究调查了活动平台单髁膝关节置换术后（MUKA）发生的关节脱位的流行病学和原因，并确定了随着外科医生经验的增加，初次人工关节脱位的发生率是否降低。
我们回顾性地分析了 14 名不同经验水平的外科医生进行的 MUKA 后发生的关节脱位病例。根据手术记录、影像学资料和手术医生的建议确定关节脱位的原因。使用卡方检验比较每位医生队列的前 50 例、第 51-100 例和接下来的 100 例单髁膝关节置换术（UKA）的关节脱位发生率。
在 1853 例 MUKA 中，有 67 例（3.6%）发生关节脱位。从 MUKA 到发生关节脱位的平均时间为 33 个月（范围 1-144 个月）；55%的关节脱位发生在 MUKA 后 2 年内。初次人工关节脱位（n=58）最常见，其次是继发性（n=6）和外伤性（n=3）。对于每位医生来说，第一次 50 例和第二次 50 例 UKA 的关节脱位发生率没有显著差异。有 2 位医生在第二次 100 例 UKA 中关节脱位发生率显著降低，而其他医生的第一次 100 例和第二次 100 例 UKA 之间的关节脱位发生率没有差异。
MUKA 后大多数关节脱位与技术错误有关，如组件位置不当或间隙失衡。本研究并未证实随着病例数量的增加，关节脱位的发生率会降低。
IV，病例系列。
