Preoperative valgus-corrected hip-knee-ankle angle and medial meniscal extrusion are useful for evaluating postoperative alignment in mobile-bearing UKA

Changquan Liu; Juncheng Ge; Yankun Jiang; Weiguo Wang; Qidong Zhang; Wanshou Guo

doi:10.1016/j.heliyon.2023.e22234

Preoperative valgus-corrected hip-knee-ankle angle and medial meniscal extrusion are useful for evaluating postoperative alignment in mobile-bearing UKA

Heliyon. 2023 Nov 17;9(11):e22234. doi: 10.1016/j.heliyon.2023.e22234. eCollection 2023 Nov.

Authors

Changquan Liu^{1

2}, Juncheng Ge³, Yankun Jiang³, Weiguo Wang^{1

2}, Qidong Zhang^{1

2}, Wanshou Guo^{1

2}

Affiliations

¹ China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
² Department of Orthopaedic Surgery, China-Japan Friendship Hospital, Beijing, China.
³ Department of Orthopaedic Surgery, Peking University China-Japan Friendship School of Clinical Medicine, Beijing, China.

Abstract

Purpose: The purposes of the study were to analyze the correlation between preoperative variables (valgus corrected hip-knee-ankle angle (vcHKA), medial osteophyte areas of the tibia and femur, and medial meniscus extrusion (MME)) and the postoperative alignment in mobile-bearing unicompartmental knee arthroplasty (UKA).

Methods: This study enrolled 109 patients (118 knees) who underwent mobile-bearing UKA between January 1, 2019 and January 1, 2023, retrospectively. Radiographic parameters, including the HKA, hip-knee-shaft angle (HKS), and valgus-corrected femorotibial angle (vcFTA), were measured using preoperative radiographs. The vcHKA was calculated as vcFTA - HKS. The medial osteophyte areas of the tibia and femur and MME were measured using knee magnetic resonance imaging (MRI). Simple and multiple linear regression analyses, univariate and multivariate logistic regression analyses, and receiver operating characteristic (ROC) curves were performed.

Results: In total, 109 patients (118 knees) were enrolled in this study. In the multiple linear regression analysis, vcHKA (β = 0.732, 95 % confidence interval (95%CI) = 0.582 to 0.881; p < 0.001) and MME (β = 0.203, 95%CI = 0.001 to 0.405; p = 0.049) were positively correlated with postoperative HKA, and postoperative HKA was modeled according to the following equation: 45.420 + (0.732° * vcHKA) + (0.203 mm × MME). In the multivariate logistic regression analysis, vcHKA (odds ratio (OR) = 2.007, 95 % CI = 1.433 to 2.810, p < 0.001) was associated with postoperative valgus malalignment independently. In the ROC curve, vcHKA (cutoff value: 180°) was predictive of postoperative valgus malalignment, with an accuracy (95%CI) of 0.862 (0.780-0.944).

Conclusion: Overcorrection of a varus knee under valgus stress radiograph (VSR) and excessive MME on preoperative MRI increase the possibility of overcorrection of postoperative alignment in mobile-bearing UKA.

Keywords: Knee magnetic resonance imaging (MRI); Medial meniscal extrusion (MME); Mobile-bearing unicompartmental knee arthroplasty (UKA); Postoperative alignment; Valgus stress radiograph (VSR); Valgus-corrected hip-knee-ankle angle (vcHKA).