To characterize discrete palmar carpal osteochondral fragmentation in horses and to document the effect of osteoarthritis and surgical removal of these fragments on functional outcome.
Retrospective case series.
25 horses.
Medical records and radiographic views were reviewed to identify horses that had radiographic evidence of palmar carpal fragmentation, which was subsequently treated by arthroscopic removal. Information collected included cause of fracture, initial and long-term clinical and radiographic findings, and functional outcome.
Palmar carpal fragmentation of 30 carpal bones was identified in 25 unilaterally affected horses. A known traumatic event was reported to cause the fragmentation in 17 of the 25 (68%) horses. Of the 25 horses, 17 (68%) had fragmentation involving the antebrachiocarpal joint, 7 (28%) had fragmentation involving the middle carpal joint, and 1 (4%) had fragmentation involving the carpometacarpal joint. The proximal aspect of the radial carpal bone was the most commonly affected site (12/30 fragments), followed by the accessory carpal bone (6/30). Of the 25 horses, 19 (76%) were not lame (sound) after surgery and returned to their intended use, 4 (16%) were considered pasture sound, and 2 were euthanized (because of severe postoperative osteoarthritis or long bone fracture during recovery from anesthesia). Eight of the 14 horses with preoperative evidence of osteoarthritis returned to function after surgery. Twelve of 17 horses with antebrachiocarpal joint fragments and 6 of 7 horses with middle carpal joint fragments returned to their previous use.
Results indicated that the prognosis for horses after arthroscopic removal of palmar carpal osteochondral fragments is good. Early intervention, before the development of osteoarthritis, is recommended.