Cutaneous Hypesthesia and Kneeling Ability After Total Knee Arthroplasty: A Randomized Controlled Trial Comparing Anterolateral and Anteromedial Skin Incision

Abstract

Background: Anterolateral skin incision can preserve the skin sensory of the anterior aspect of the knee and may improve kneeling ability after total knee arthroplasty (TKA).

Methods: This is a prospective, 2-arm, parallel-group, randomized, controlled trial involving patients scheduled for TKA. A total of 118 patients (162 knees) were randomly assigned to receive anterolateral skin incision or anteromedial skin incision with 1:1 treatment allocation. The surgical techniques other than skin incision were identical in both groups. The area of cutaneous hypesthesia was measured by a nonblinded assessor, and kneeling ability was evaluated by 2 blinded assessors at 12 months after surgery.

Results: The area of cutaneous hypesthesia was significantly smaller in the anterolateral skin incision group than the anteromedial skin incision group (3.0 ± 8.7 cm² vs 10.6 ± 18.6 cm²; 95% confidence interval, 2.8-12.3 cm²; P = .0019). The rates of patients judged to be able to kneel were significantly higher in the anterolateral skin incision group by both assessors (81% vs 60%; P = .025 and 81% vs 59%; P = .015, respectively) with almost perfect agreement between the 2 assessors (kappa value = 0.94). There were no significant differences in terms of complication rate, including wound complications, between the 2 groups (P > .05).

Conclusion: Compared with anteromedial skin incision, anterolateral skin incision may provide less cutaneous hypesthesia and better kneeling ability after TKA without increasing complication rate.

Keywords: knee; kneeling; patient satisfaction; primary arthroplasty; saphenous nerve; skin incision.