Treatment response and athletic outcome of foals with tarsal valgus deformities: 39 cases (1988-1997)
Dutton, D.M.; Watkins, J.P.; Honnas, C.M.; Hague, B.A.
Journal of the American Veterinary Medical Association 215(10): 1481-1484
1999
ISSN/ISBN: 0003-1488 PMID: 10579047 Document Number: 505676
The response to various treatments and long-term outcome of 39 foals with tarsal valgus deformities was studied retrospectively. Radiographic views of the tarsus were evaluated for incomplete ossification of tarsal bones and were classified as normal in appearance, type-I incomplete ossification, or type-II incomplete ossification. Radiographic assessment revealed that 22 foals (56%) had concomitant tarsal valgus deformities and incomplete ossification of the tarsal bones. Eight of 19 foals with tarsal valgus deformities that were treated with periosteal stripping responded favourably. Foals <=60 days old were significantly more likely to respond to periosteal stripping than older foals. Five of 8 foals with tarsal valgus deformities that were treated with growth plate retardation responded favourably. 11 of 21 foals with long-term follow-up performed as intended. Compared with foals with type-II incomplete ossification, foals with tarsal bones that had a normal radiographic appearance or type-I incomplete ossification were significantly more likely to perform as intended. It is concluded that foals with tarsal valgus deformities should have lateromedial radiographic views of the tarsus obtained to assess the tarsal bones for incomplete ossification. Because foals with type-II incomplete ossification of the tarsal bones respond poorly to periosteal stripping alone, treatment by growth-plate retardation is recommended.