Zuiderbaan Hendrik A, van der List Jelle P, Chawla Harshvardhan, Khamaisy Saker, Thein Ran, Pearle Andrew D
Department of Orthopaedic Surgery, Computer Assisted Surgery Center, Hospital for Special Surgery, Weill Cornell Medical College, New York, New York.
J Arthroplasty. 2016 Jul;31(7):1453-8. doi: 10.1016/j.arth.2015.12.038. Epub 2016 Feb 28.
Unexplainable pain after medial unicompartmental knee arthroplasty (UKA) remains a leading cause for revision surgery. Therefore, the aim of this study is to identify the patient-specific variables that may influence subjective outcomes after medial UKA to optimize results.
Retrospectively, we analyzed 104 consecutive medial UKA patients. The evaluated parameters consisted of age, body mass index, gender, preoperative radiographic severity of the various knee compartments, and preoperative and postoperative mechanical axis alignments.
At an average of 2.3-year follow-up, our data demonstrate that body mass index, gender, and preoperative severity among the various knee compartments do not influence Western Ontario and McMaster Universities Arthritis Index (WOMAC) results. Preoperatively, patients aged <65 years had inferior WOMAC stiffness (4.6 vs 2.9, P = .001), pain (9.7 vs 7.6, P = .041), and total (37.2 vs 47.6, P = .028) scores vs patients aged ≥65 years. Postoperatively, only the difference on the WOMAC stiffness subscale remained significant between both age groups, in favor of patients aged ≥65 years (1.0 vs 1.5, P = .035). A postoperative varus mechanical axis alignment of 1°-4° correlated to significantly superior WOMAC pain (P = .03), function (P = .04), and total (P = .04) scores compared to a varus of ≤1° or ≥4°.
Our data suggest that greater pain relief can be expected in patients aged <65 years and that a postoperative lower limb alignment of 1°-4° varus should be pursued. Taking these factors into consideration will help to maximize clinical outcomes, fulfill patient expectations after medial UKA, and subsequently minimize revision rates.
内侧单髁膝关节置换术（UKA）后出现的不明原因疼痛仍是翻修手术的主要原因。因此，本研究的目的是确定可能影响内侧UKA术后主观结果的患者特异性变量，以优化手术效果。
我们回顾性分析了104例连续接受内侧UKA手术的患者。评估参数包括年龄、体重指数、性别、术前各膝关节间室的影像学严重程度以及术前和术后的机械轴对线情况。
平均随访2.3年，我们的数据表明，体重指数、性别以及各膝关节间室的术前严重程度均不影响西安大略和麦克马斯特大学骨关节炎指数（WOMAC）结果。术前，年龄＜65岁的患者与年龄≥65岁的患者相比，WOMAC僵硬评分（4.6对2.9，P = 0.001）、疼痛评分（9.7对7.6，P = 0.041）和总分（37.2对47.6，P = 0.028）更低。术后，两个年龄组之间仅在WOMAC僵硬子量表上的差异仍然显著，年龄≥65岁的患者更具优势（1.0对1.5，P = 0.035）。与内翻角度≤1°或≥4°相比，术后内翻机械轴对线为1°-4°与显著更高的WOMAC疼痛评分（P = 0.03）、功能评分（P = 0.04）和总分（P = 0.04）相关。
我们的数据表明，年龄＜65岁的患者有望获得更大程度的疼痛缓解，并且术后应追求下肢1°-4°的内翻对线。考虑这些因素将有助于最大化临床效果，满足内侧UKA术后患者的期望，并随后降低翻修率。
