Effect of Knee Valgus Deformity on Symptomatic Venous Thromboembolism and Prosthesis Revision Risk after Total Knee Arthroplasty: A Multicenter Retrospective Study

Abstract

Objective: Symptomatic venous thromboembolism (VTE) and prosthesis failure are the most serious complications after total knee arthroplasty (TKA). However, whether knee valgus deformity aggravates these complications has not been fully clarified. To study the difference between perioperative symptomatic VTE and prosthesis revision rate in patients with valgus knee osteoarthritis by comparing with patients undergoing TKA for varus deformity and analyze the reasons for revision. At the same time, the distribution and radiographic features of lower extremity deep venous thrombosis were recorded.

Methods: The data of patients who underwent TKA in two tertiary hospitals from January 2016 to December 2020 were retrospectively reviewed, and a total of 8917 patients were included. According to preoperative manifestations of knee malformations, all patients were divided into two groups: valgus group (n = 412) and varus group (n = 8505). Main indicators included the incidence of symptomatic VTE and prosthesis revision. Secondary outcomes included general information on operative time, Kellgren and Lawrence score, total hospital stay, and total costs. The patient data of the two groups were analyzed by Pearson chi-square test, Student t test, or Mann-Whitney U test. The revision was evaluated using Kaplan-Meier survival analysis.

Results: The proportion of valgus knees in TKA patients was 4.62% (412/8917). The incidence of VTE was 6.23‰ (53/8505) and 16.99‰ (7/412) in the varus and valgus groups, and the results were statistically different (p = 0.009). There was no significant difference in echogenicity, number of occluded vessels, and thrombus length between the valgus group (p = 0.102; p = 0.645; p = 0.684). Patients with valgus deformity had 12.14‰ (5/412) prosthesis revision, the incidence of varus deformity was 4.82‰ (41/8505), and the revision risk of valgus group was 2.5 times higher than varus group, and the results were statistically different (p = 0.043). The operation time and hospital stay in the valgus group were longer than those in the varus group, and the results were statistically different (p = 0.018; p < 0.001).

Conclusions: Valgus deformity increases risk of symptomatic VTE and prosthesis revision after TKA. These results have guiding significance for the prevention of complications after TKA in patients with valgus deformity.

Keywords: Revision; Total Knee Arthroplasty; Valgus; Varus; Venous Thromboembolism.

FIGURE 1

Survival curves of Kaplan–Meier prosthesis in two groups.

FIGURE 2

A 67‐year‐old woman with valgus deformity of the right knee underwent TKA. (A) One month before surgery, weight‐bearing radiographs of the whole lower limb were taken. (B) Anteroposterior position of right knee joint 3 days after TKA. (C) Lateral position of right knee joint 3 days after TKA. (D) Anteroposterior position of right knee joint 6 months after TKA. (E) Lateral position of right knee joint 6 months after TKA. (F) Anteroposterior position of right knee joint 11 months after TKA. (G) Lateral position of right knee joint 11 months after TKA. (H) Anteroposterior position of right knee joint 2 days after revision. (I) Lateral position of right knee joint 2 days after operation. (J) Anteroposterior position of right knee joint 1 month after revision. (K) Lateral position of right knee joint 1 month after operation.