33rd Annual Scientific Meeting proceedings

Objective
Describe a technique for arthroscopic removal of osteochondral fragments originating from the dorsal aspect of the accessory carpal bone and compare radiographic findings of the carpi on survey and pre-sale radiographs.

Methods
Osteochondral fragments on the dorsal aspect of the accessory carpal bone identified during initial survey or later pre-sale radiographic examinations were removed arthroscopically in 41 Thoroughbred yearlings. Presence of concurrent osteoarthritis of the antebrachiocarpal joint was noted as well as development of a fragment between survey and pre-sale radiographs. Fragment removal was aided with a bipolar radiofrequency probe and confirmed by intra-operative radiography.

Results
Fragments were successfully removed in all but one case where the fragment was noted to be dislodged from the bed and not identified arthroscopically. No post-operative complications occurred. Survey radiographs identified concurrent osteoarthritis in 16 of 32 (50%) cases while 16 of 32 (50%) cases did not and none of those later developed osteoarthritis on pre-sale radiographs. Pre-sale radiographs identified nine cases which developed a fragment not seen on survey radiographs and all nine also developed osteoarthritis.

Conclusions
Fragments on the dorsal aspect of the accessory carpal bone can be removed using an arthroscopic approach in the proximal lateral recess of the antebrachiocarpal joint coupled with a radiofrequency probe to aid dissection of the fragment which has not been described. Early identification and removal of dorsal accessory carpal bone fragments can reduce the development of osteoarthritis of the antebrachiocarpal joint. Intervention is recommended prior to the fragment becoming dislodged from the osteochondral bed.