Donor-Site Morbidity Analysis of Thenar and Hypothenar Flap

Abstract

Background For the small glabrous skin defect, thenar and hypothenar skin are useful donor and it has been used as a free flap. Because of similar skin characteristics, both flaps has same indications. We will conduct comparative study for the donor morbidity of the thenar and hypothenar free flap. Methods From January 2011 to December 2021, obtaining demographic data, characteristics of each flap and complications using retrospective chart review. And the patient who had been follow more than 6 month donor outcomes measured using photographic analysis and physical examination. General pain, assessed by Numeric Rating Scale (NRS) score, Neuropathic pain, assessed by DN4 (Douleur Neuropathique 4 Questions) score, Scar appearance, assessed by modified Vancouver Scar Scale (mVSS), and Patient satisfaction, assessed on a 3-point scale. Statistical analysis was performed on the outcomes. Results Out of the 39 survey respondents, 17 patients received Thenar free flaps, and 22 patients received Hypothenar free flaps. Thenar group had higher morbidity of NRS, DN4, and mVSS (p<0.05). Despite the Hypothenar group showing greater satisfaction on the 3-point scale, the difference was not significant (p=0.085). Linear regression analysis indicated that flap width did not have a notable impact on the outcome measures, and multiple linear regression analysis revealed no significant interaction between flap width and each of the outcome measures. Conclusion Higher donor morbidity in general pain, neuropathic pain, and scar formation was noted in the Thenar free flap compared to the Hypothenar free flap. However, no difference in overall patient satisfaction.