Primary microsurgical repair of ring avulsion amputation injuries

Patients with ring avulsion injuries of the fourth and fifth digits often demand attempts at reconstruction rather than completion of the amputation. In the past, this has led to reconstruction involving a staged series of operations with results that were often less than desirable. Seven patients with ring avulsion amputation injuries that were reconstructed by use of microsurgical reanastomoses are reported. All were classified as either Carroll type IV or Urbaniak type III. Six patients (85%) had a successful replantation leading to a useful finger. The operating time averaged 5.5 hours. On average, 1.9 arteries (range 1 to 2) and 3.3 veins (range 2 to 5) were repaired for each digit. Average hospital stay was 6.7 days (range 4 to 15). Average range of motion was 0(2)/84(2) for metacarpophalangeal joint and 15(2)/90(2) for proximal interphalangeal joint (PIP) with distal interphalangeal joint ankylosis at between 0(2) and 15(2) of flexion. Sensibility was protective in all cases and good in three. If the PIP joint was damaged, completion of amputation was the treatment of choice. If the amputation is distal to the PIP with a functional superficialis tendon, primary microsurgical repair is the treatment of choice in complex ring avulsion injuries.