Department of Orthopaedic Surgery, Gifu University Graduate School of Medicine, Gifu, Japan.
Knee Surg Sports Traumatol Arthrosc. 2024 Jan;32(1):47-53. doi: 10.1002/ksa.12019. Epub 2024 Jan 3.
Restricted kinematically aligned total knee arthroplasty (rKA-TKA) may not restore the constitutional varus alignment in most patients with knee osteoarthritis. This study aimed to investigate (1) the extent to which constitutional lower limb alignment can be restored by rKA-TKA using an anatomically designed implant and (2) which lower limb alignment parameters are associated with patient-reported outcome measures (PROMs).
This study included 60 patients who underwent rKA-TKA using an anatomically designed implant. Radiographic alignment parameters, including mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), coronal hip-knee-ankle angle (HKA), coronal joint line obliquity (JLO), posterior tibial slope (PTS), single-leg standing knee flexion angle (KFA), sagittal JLO, and arithmetic HKA (aHKA), were evaluated preoperatively and postoperatively. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) was used for clinical evaluation.
The mLDFA, MPTA, and aHKA showed no significant differences before and after surgery. Coronal HKA and PTS have significantly changed from 8.1 ± 8.7° and 9.9 ± 8.6° preoperatively to 3.5 ± 3.1° and 2.5 ± 2.0° postoperatively, respectively (p < 0.001 for each comparison). The postoperative WOMAC total score was significantly correlated with the KFA (r = 0.4063, p = 0.0034) and sagittal JLO (r = -0.3435, p = 0.0157). Postoperative KFA is a causal factor for the increased postoperative WOMAC total score (r = 1.416, 95% confidence interval: 0.491-2.342, p = 0.003).
rKA-TKA using an anatomically designed implant can restore constitutional coronal lower limb alignment, while postoperative KFA and sagittal JLO were associated with poor PROMs. Care should be taken for the postoperative KFA because it is a risk factor for poor PROMs.
Level III, case-control study.
在大多数膝骨关节炎患者中，受限运动学对线全膝关节置换术（rKA-TKA）可能无法恢复其固有内翻对线。本研究旨在探究：（1）使用解剖设计植入物恢复 rKA-TKA 固有下肢对线的程度；（2）哪些下肢对线参数与患者报告的结局测量（PROM）相关。
本研究纳入 60 例行 rKA-TKA 治疗的患者，均使用解剖设计植入物。评估术前和术后的影像学对线参数，包括机械外侧远端股骨角（mLDFA）、内侧近端胫骨角（MPTA）、冠状髋膝踝角（HKA）、冠状关节线倾斜角（JLO）、胫骨后倾角（PTS）、单腿站立膝关节屈曲角度（KFA）、矢状面 JLO 和算术 HKA（aHKA）。采用 Western Ontario 和 McMaster 大学骨关节炎指数（WOMAC）进行临床评估。
mLDFA、MPTA 和 aHKA 在术前和术后无显著差异。冠状 HKA 和 PTS 分别从术前的 8.1±8.7°和 9.9±8.6°显著变化至术后的 3.5±3.1°和 2.5±2.0°（每个比较均 p<0.001）。术后 WOMAC 总分与 KFA（r=0.4063，p=0.0034）和矢状面 JLO（r=-0.3435，p=0.0157）显著相关。术后 KFA 是增加术后 WOMAC 总分的一个原因（r=1.416，95%置信区间：0.491-2.342，p=0.003）。
使用解剖设计植入物的 rKA-TKA 可恢复固有冠状下肢对线，而术后 KFA 和矢状面 JLO 与较差的 PROM 相关。应注意术后 KFA，因为它是 PROM 较差的一个危险因素。
III 级，病例对照研究。
