Inui Hiroshi, Taketomi Shuji, Yamagami Ryota, Kawaguchi Kohei, Nakazato Keiu, Tanaka Sakae
Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
J Knee Surg. 2020 Mar;33(3):294-300. doi: 10.1055/s-0039-1678539. Epub 2019 Feb 8.
There have been many reports on the clinical outcomes of Oxford unicompartmental knee arthroplasty (UKA); however, none have investigated the influence of flexion angle after UKA on clinical outcomes. The objective of this study was to clarify the relationship between outcomes and the postoperative maximum flexion angle and reveal the necessary factors for maximum flexion angle ≥ 140 degrees which is considered necessary for Asian populations. We categorized 212 UKA patients into the following three groups based on the postoperative maximum flexion angle: group 1 had flexion angle ≥ 140 degrees in 80 patients (38%), group 2 had 130 degrees ≤ flexion angle < 140 degrees in 80 patients (38%), and group 3 had flexion angle < 130 degrees in 52 patients (24%). Furthermore, we compared the postoperative clinical outcomes between the three groups and conducted multivariable regression analyses to assess parameters affecting the flexion angle. Postoperative Knee Society function scores for group 1 was significantly higher than for group 3. Group 1 had higher mean knee injury and osteoarthritis outcome scores (KOOS) in all subscales and significantly higher KOOS scores in the sports and quality of life subscales compared with group 2 and in all subscales compared with group 3. Multivariable logistic regression showed that preoperative flexion angle and tibial component posterior slope were associated with maximum flexion angle ≥ 140 degrees. Maximum flexion angle ≥ 140 degrees after Oxford UKA improved the clinical results, particularly for patient-reported outcomes. Furthermore, the tibial posterior slope was an important factor in achieving maximum flexion angle ≥ 140 degrees in UKA patients.
关于牛津单髁膝关节置换术（UKA）的临床结果已有许多报道；然而，尚无研究探讨UKA术后屈曲角度对临床结果的影响。本研究的目的是阐明结果与术后最大屈曲角度之间的关系，并揭示亚洲人群最大屈曲角度≥140度所需的必要因素。我们根据术后最大屈曲角度将212例UKA患者分为以下三组：第1组80例患者（38%）屈曲角度≥140度，第2组80例患者（38%）屈曲角度为130度≤屈曲角度＜140度，第3组52例患者（24%）屈曲角度＜130度。此外，我们比较了三组之间的术后临床结果，并进行多变量回归分析以评估影响屈曲角度的参数。第1组的术后膝关节协会功能评分显著高于第3组。与第2组相比，第1组在所有子量表中的平均膝关节损伤和骨关节炎结果评分（KOOS）更高，在运动和生活质量子量表中的KOOS评分显著高于第2组，与第3组相比，在所有子量表中均更高。多变量逻辑回归显示，术前屈曲角度和胫骨假体后倾与最大屈曲角度≥140度相关。牛津UKA术后最大屈曲角度≥140度可改善临床结果，尤其是患者报告的结果。此外，胫骨后倾是UKA患者实现最大屈曲角度≥140度的重要因素。
