Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea.
J Arthroplasty. 2020 Nov;35(11):3305-3310. doi: 10.1016/j.arth.2020.06.027. Epub 2020 Jun 17.
This study aimed to investigate the change in ankle varus incongruencies following total knee replacement (TKR) in patients with preoperative genu varum deformity of ≥10°.
The study cohort was composed of patients who underwent TKR in a single institution for knee osteoarthritis with preoperative genu varum deformity of ≥10° and concomitant varus ankle incongruencies. Eight radiographic measurements were evaluated preoperatively and postoperatively: mechanical tibiofemoral angle, mechanical lateral distal femoral angle, medial proximal tibial angle, lateral distal tibial angle, tibial plafond inclination, talar inclination, tibiotalar tilt angle (TTTA), and tibia-mechanical axis angle. Of these, TTTA represented the quantitative degree of ankle joint incongruency.
A total of 110 patients (male = 2; female = 108) were included in the analysis. The mean patient age was 68.9 (standard deviation [SD] 7.2) years at the time of TKR. All radiographic measurements showed significant changes postoperatively, representing the appropriate correction of genu varum deformity and restoration of the mechanical axis. Nineteen patients (17.3%) showed postoperative decrease in TTTA, 2 (1.8%) remained the same, and 89 (80.9%) showed increase. Overall, mean preoperative and postoperative TTTA were 3.3° (SD 2.2°) and 4.7° (SD 2.9°), respectively (P < .001), representing the aggravation of varus ankle incongruencies.
Varus ankle incongruencies showed aggravation following TKR despite correction of genu varum deformity and restoration of the mechanical axis. This could be an important cause of postoperative increase or development of ankle pain following TKR. Therefore, patients with preoperative varus ankle incongruencies need to be warned of possible aggravation of ankle symptoms and be evaluated before TKR.
Prognostic level III.
本研究旨在探讨术前膝内翻畸形≥10°的全膝关节置换（TKR）患者术后踝关节内翻不匹配的变化。
研究队列由在一家机构接受 TKR 治疗的膝关节骨关节炎患者组成，这些患者术前膝内翻畸形≥10°且伴有内翻踝关节不匹配。术前和术后评估了 8 项影像学测量值：机械胫股角、机械外侧远端股骨角、内侧近端胫骨角、外侧远端胫骨角、胫骨平台倾斜角、距骨倾斜角、距骨-胫距角（TTTA）和胫骨机械轴角。其中，TTTA 代表踝关节关节不匹配的定量程度。
共纳入 110 例患者（男 2 例，女 108 例）进行分析。TKR 时患者的平均年龄为 68.9 岁（标准差 [SD] 7.2）。所有影像学测量值均显示术后有显著变化，表明适当纠正了膝内翻畸形并恢复了机械轴。19 例（17.3%）患者术后 TTTA 降低，2 例（1.8%）患者 TTTA 不变，89 例（80.9%）患者 TTTA 增加。总的来说，术前和术后 TTTA 的平均值分别为 3.3°（SD 2.2°）和 4.7°（SD 2.9°）（P<.001），表明内翻踝关节不匹配加重。
尽管纠正了膝内翻畸形并恢复了机械轴，但 TKR 后仍出现内翻踝关节不匹配加重。这可能是 TKR 后踝关节疼痛增加或发展的一个重要原因。因此，术前有内翻踝关节不匹配的患者需要警惕踝关节症状可能加重，并在 TKR 前进行评估。
预后 III 级。
