Sensory restoration of the critical border of the small finger by an emergency heterodigital nerve transfer after circular saw injury

Traumatic nerve injuries involving the distal part of the upper extremity may significantly affect the function of the hand if left untreated. An alternative to nerve autografts for treating digital nerve injuries are nerve transfers. We present the surgical management of a 2.5 cm nerve defect to the proper digital ulnar nerve of the small finger after circular saw injury to the palm of the hand with multiple neurovascular involvement and the use of a non-critical heterodigital nerve transfer for restoration of the critical functional border of the small finger. At 14 months postoperative the sensory recovery grading scale was S4 for the 4th finger and radial border of the 5th finger (primary repair) and S3+ for the ulnar border of the 5th finger (nerve transfer). Donor site morbidity consisted of anesthesia of the ulnar sided tip of the middle finger. Emergency nerve transfer of the proper ulnar digital nerve of the middle finger is a feasible surgical technique for the restoration of the critical ulnar digital border of the small finger after traumatic injuries but with the disadvantage of an insensate donor site.