APPLICATION OF A HOOK PLATE FOR MANAGEMENT OF EQUINE ULNAR FRACTURES

Closed fractures of the proximal aspect of the ulna were repaired in 1 0 horses younger than or equal to 6 months of age by application of a hook plate using a tension band principle. Ulnar fractures were classi fied as type 1A (2 horses), type 1B (4 horses), type 2 (1 horse), type 3 (1 horse), and type 4 (2 horses); all fractures had displacement of a proximal fragment. Complications were implant deformation (4 horses ), screw pullout (1 horse), osseous sequestration (1 horse), ulnar fra cture through a hole used to apply a tension device (1 horse), and met acarpophalangeal deformity associated with a displaced anconeal fragme nt (1 horse). Hook deformation was likely associated with failure to i nsert screws in all of the proximal holes of the plate and also in two horses, possibly with difficult recovery from anesthesia. Seven horse s were discharged from the hospital and were being used for athletic a ctivities. Insertion of the hook through the tendon of the triceps mus cle and incorporation of the fragment within the hook can be used to e ffectively reduce and stabilize a fragment that might otherwise not ho ld screws. (C)Copyright 1996 by The American College of Veterinary Sur geons