The weight-bearing FLX before and after surgery (the preoperative ones were taken within 1 month before surgery and the postoperative ones 3 days after surgery) of the patients were collected via the picture archiving and communication system (PACS) and imported into Autodesk AutoCAD 2019 for measurement of preoperative hip-knee-ankle (HKA) angles and postoperative frontal femoral component angle (FFC), lateral femoral component angle (LFC) [30 (link)], frontal tibial component angle (FTC), lateral tibial component angle (LTC) [31 , 32 (link)], and HKA angles (Fig. 3). Three surgeons specializing in TKA performed blind measurement twice; in order to ensure that the raters had sufficient forgetting time, each was required to measure at an interval for more than 2 weeks [33 (link), 34 (link)]. For HKA, the varus was defined as negative and the valgus positive; for LTC, the retroversion was positive and the anteversion negative. Values exceeding the target value by 3° were recorded as outliers, and the percentage of outliers was calculated. Patients with varus knee preoperatively who had HKA valgus greater than 1° after surgery and patients with valgus knee preoperatively who had HKA varus greater than 1° after surgery were recorded as overcorrected, and the percentage of overcorrection was calculated.
Medical records such as the operation time, tourniquet time, hospital stay, intraoperative bleeding, incidence of postoperative complications, hemoglobin value 1 day before the operation, 1 day after the operation, and 3 days after operation were collected via the electronic medical record management system. And visual analog scale (VAS) score and New Knee Society Score (NEW-KSS) [35 (link)] before operation and 1, 6, and 12 months after operation were recorded.
This study has been approved by the local Ethics Committee (No. KY2019123).
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