No Effect of Oral Mecobalamin on Skin Numbness at 3 Months After Total Knee Arthroplasty: A Randomized, Double-Blinded, Placebo-Controlled Superiority Trial.

Background: An area of skin numbness (AON) around an incision commonly occurs following total knee arthroplasty (TKA). Mecobalamin has been shown to facilitate peripheral nerve recovery in various conditions; accordingly, the present study aimed to investigate the ameliorative effect of mecobalamin on AON following TKA, as compared with a placebo. Methods: This superiority study was a double-blinded, randomized controlled trial. All patients undergoing primary TKA were assessed for eligibility. Included patients were randomized to receive either mecobalamin (500 µg, twice daily) or placebo (corn starch powder; 500 µg, twice daily) for 3 months. The primary outcome was the change in the AON around the surgical site from 2 weeks to 3 months after TKA. Secondary outcomes included the rates of different adverse events, functional outcomes, and visual analogue scale patient satisfaction scores. Results: A total of 154 patients were enrolled, with 77 patients each in the mecobalamin and placebo groups. The mean AON among patients in the mecobalamin group was 61.6 cm Conclusions: Mecobalamin did not demonstrate superiority over a placebo in reducing the AON around the surgical site at 3 months after primary TKA. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.