Purpose
To highlight the free thenar flap as a functional option in the reconstruction of an extensive volar finger soft tissue defect caused by a high-pressure injection (HPI) injury.
Case Report
A 53-year-old right-hand dominant male handyman sustained a HPI injury to his left middle finger with a water-based paint while working at home. He presented to our emergency department 48 hours later with increasing pain and swelling (see image). Two debridements resulted in a large volar soft tissue defect extending from the proximal interphalangeal joint crease up to and involving the fingertip (see image).
At day five post-injury, an ipsilateral free thenar flap was raised and anastomosed to the ulnar digital artery and dorsal vein to reconstruct the defect. The donor site was closed with a full thickness skin graft. After a smooth post-operative course he was discharged at day five. On outpatient review at three months, there was complete flap survival and the patient had returned to work with full range of motion in flexion and preserved fingertip sensation (see image).
Discussion
Described Kamei in 1993, the free thenar flap is based on a consistent superficial palmar branch of the radial artery1. Since this time, it has been described in the reconstruction of a variety of volar hand defects2. High-pressure injection injuries are rare and potentially devastating injuries, often resulting in significant soft tissue loss post-debridement. Descriptions of free thenar flap reconstruction of HPI injuries are scarce in the literature.
Conclusion
The free thenar flap is an excellent source of glaborous skin for the functional reconstruction of volar finger soft tissue defects following HPI injury.