Amputation of Finger by Horse Bite With Complete Avulsion of Both Flexor Tendons

Amputation of fingers with tendon avulsion occurs through a traction injury, and most occur through a ring avulsion mechanism. Usually the flexor digitorum profundus is torn out with the amputated finger. Replantation usually is recommended only when the amputation is distal to the flexor digitorum superficialis insertion. Animal bites are relatively common, with a decreasing order of frequency of dogs, cats, and humans. Horse bites are relatively infrequent but are associated with crush injuries and tissue loss when they occur. This article describes a 23-year-old man with amputation of his middle finger at the level of the proximal phalanx after being bitten by a horse. The amputated stump was avulsed with the middle finger flexor digitorum profundus and flexor digitorum superficialis torn from the muscle-tendon junction from approximately the middle of the forearm. The patient had no other injuries, and he was able to move his other 4 fingers with only mild pain. As the amputated digit was not suitable for replantation, the wound was irrigated and debrided. The edges of the phalanx were trimmed, and the edges of the wound were sutured. Tetanus toxoid and rabies vaccine were administered, along with intravenous amoxicillin and clavulanic acid. The patient was discharged from the hospital 2 days later, with no sign of infection of the wound or compartment syndrome of the forearm. This case demonstrates the weakest point in the myotendinous junction and emphasizes the importance of a careful physical examination in patients with a traumatic amputation.