The Thenar Flap for Allen Type I and II Fingertip Injuries in Adults: A Retrospective Series and Rehabilitation Protocol

Abstract

Background: Fingertip injuries are among the most common traumatic lesions of the upper extremity and carry a disproportionate functional and socioeconomic impact. Injuries corresponding to Allen type I and selected type II patterns frequently involve volar pulp loss with exposed bone, rendering conservative management or skin grafting unreliable. Despite the development of various local reconstructive options, the thenar flap remains a valuable technique for achieving durable, sensate coverage.

Methods: A retrospective case series was conducted including adult patients who underwent staged thenar flap reconstruction for acute fingertip injuries. Eleven patients (10 male, 1 female; mean age 56 years) were treated. Follow-up of at least 7 months was achieved using patient-reported and objective outcome measures, including Visual Analog Scale (VAS) for pain, static two-point discrimination (2PD), and active range of motion (ROM). Surgical technique followed contemporary refinements in flap design ("mirror image" planning), positioning, and staged division, combined with a structured postoperative rehabilitation protocol.

Results: No flap losses or secondary infections were observed. Functional outcomes were favorable, with preservation of interphalangeal joint motion in all but one patient, who developed a mild cicatricial contracture not requiring surgical intervention. One patient reported persistent sensory disturbance; however, protective sensibility was preserved in all evaluated cases. No clinically significant nail deformities or donor-site complications were recorded.

Conclusion: In adult patients with fingertip injuries corresponding to Allen type I and selected type II patterns, the thenar flap remains a reliable and effective reconstructive option. When performed using modern planning principles and combined with structured rehabilitation, it provides durable glabrous padding, preserves digital length, and supports satisfactory functional and sensory recovery with a low complication profile.