The risk of symptomatic venous thromboembolism after total knee arthroplasty for valgus deformity is comparable to that for varus deformity, but revision is 2.5 times higher

Purpose: To study the difference of perioperative symptomatic venous thromboembolism (VTE) and prosthesis revision rate in patients with valgus knee osteoarthritis by comparing with patients undergoing total knee arthroplasty(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 8917 patients who underwent primary unilateral TKA in our hospital from 2011 to 2020 were retrospectively analyzed and all patients assigned to 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. Results In our hospital, the proportion of valgus knees in TKA patients was 4.62% (412/8917), the incidence of VTE events was 6.17‰ (55/8917), and most deep venous thrombosis occurred in the distal lower extremities (51/55), mainly in the intermuscular veins (43/53). The incidence of VTE was 6.23‰(53/8505) and 4.85‰(2/412) in the varus and valgus groups, and the results were not statistically different (P = 0.727). There was no significant difference in echogenicity, number of occluded vessels and thrombus length between the valgus group (P = 0.942, P = 0.653, P = 0.684). Total prosthesis revision after TKA was 5.16‰(46/8917), and infection was the main reason for revision (26/46). 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 The proportion of valgus knees in TKA patients in our hospital was 4.62%, which was lower than that in previous reports. Compared with the varus group, no difference was found in the incidence of symptomatic VTE, thrombus location, echogenicity, number of occluded vessels, and thrombus length after TKA in the valgus group, but the prosthesis revision rate was 2.5 times higher in the valgus group than in the varus group,higher revision rates may be associated with longer operative times.