Periosteal transection and periosteal stripping for correction of angular limb deformities in foals.

Valgus deformities were created in 6 pony foals by hemicircumferential transection of the periosteum and periosteal stripping (HCTP and PS) just proximally to the distal physis on the medial side of 1 radius (principal thoracic limb). The opposite thoracic limb served as a control. One month after this surgical procedure was done, the limbs were radiographed and the angle of deviation was determined. All horses developed a valgus deformity of the principal limb. In an effort to correct the acquired valgus deformity, the 2nd surgical procedure was performed--HCTP and PS on the lateral aspect of the principal radius. The carpal valgus deformities corrected within 3 months. To determine the differences in growth, stainless steel wires were introduced into both legs of each foal at certain points on the distal part of the radius. Growth changes in response to the HCTP and PS were not significantly different in the 2 groups of thoracic limbs. Increased bone growth did occur at the medial aspect of the bone in response to the 1st surgical procedure and an increase was found on the lateral aspect of the bone in response to the 2nd. The reasons for the statistically insignificant changes are discussed. A significant increase in bone width at the level of growth plate developed in response to the 1st and 2nd HCTP and PS procedures.