Outcome of lag-screw treatment of incomplete fractures of the frontal plane of the radial facet of the third carpal bone in horses.
OBJECTIVE
To describe outcomes for horses diagnosed with incomplete, non-displaced fractures of the frontal plane of the radial facet (INFR) of the third carpal bone (C3) treated by placement of a lag screw across the fracture under arthroscopic guidance.


METHODS
Horses (n=13) diagnosed with INFR and treated between December 1999 and January 2005 using a lag screw placed over the fracture were studied. For each case, five horses matched for sire, age and sex which were not known to have INFR were sought for comparison. Racing performance data were collected from a commercial online database. The racing performance of cases pre- and post-operatively, and of cases and matched horses in the post-operative period was compared.


RESULTS
Sixteen INFR were found in the 13 horses. Radiographic evidence of healed fracture lines 2-4 months after surgery was seen in 11/16 (69%) fractures; 11/13 (85%) cases raced again after a median recovery period of 292 (range 149-681) days. Treatment was considered successful in 9/13 (69%) cases, which were still in training or had been retired for reasons other than lameness localised to the middle carpal joint at the end of the study period. Just 6/13 (46%) cases had raced prior to injury. The racing ability pre- and post-operatively of five cases was compared, three (60%) of which performed better post-operatively than they had before. There was no significant difference in racing longevity or ability post-operatively between patients and matched (control) horses.


CONCLUSIONS
Post-operatively, there was little difference in the racing performance between horses diagnosed with INFR which had a lag screw placed across the fracture line and horses matched for sire, age and sex which were not known to have INFR.


CONCLUSIONS
Horses which were diagnosed with INFR of C3 and had a lag screw placed across the fracture had a good prognosis for future racing performance.
Rutherford
D J
DJ
Massey Equine, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand. d.j.rutherford@massey.ac.nz
Bladon
B
B
Rogers
C W
CW
D000818:Animals; D001863:Bone Screws / Q000662:veterinary*; D002350:Carpus, Animal / Q000000981:diagnostic imaging / Q000601:surgery*; D016022:Case-Control Studies; D005260:Female; D017102:Fracture Healing; D006736:Horses / Q000293:injuries* / Q000601:surgery; D008297:Male; D010805:Physical Conditioning, Animal; D011859:Radiography; D011996:Records / Q000662:veterinary; D012189:Retrospective Studies; D016896:Treatment Outcome