NM Fitzpatrick, KL Perry, S Girling, R Yeadon.
Fitzpatrick Referrals, Farnham, United Kingdom

ACVS Abstract 2007

Surgical intervention for antebrachial growth deformity aims to establish functional limb axis and limit elbow or carpal pathology. 15 antebrachii (13 dogs) were operated. Mean age 9.2 months. Single transverse radial osteotomy at the deformity apex and oblique proximal ulnar osteotomy were performed with acute realignment referenced from the frontal plane of the humero-radial joint.

Nine limbs were corrected using 1/3 ring arches and linear frame components (Linear-Arch-Pin-Frame, LAPF) and six limbs with two 1/3 ring arch frame components (Double-Arch-Pin-Frame, DAPF) with a minimum of three pins per frame component. Orthogonal preand post-operative radiographs were used to determine the frontal (FPA) and sagittal plane (SPA) anatomic axes. Pre- and post-operative function and cosmesis were assessed. Frame removal occurred within 7.5 weeks. Lameness and joint pain had resolved within 17 weeks.

Rotational deformity in frontal and sagittal planes was corrected. Cosmesis proved less satisfactory for LAPF than DAPF. All cases achieved good function. For 15 radii, FPA and SPA significantly improved by paired t test. Divergent pins allow maximum purchase in minimum bone stock and avoid growth plates. Three-dimensional movement is possible and pre-operative planning is not necessary. LAPF has less scope for three-dimensional correction with less desirable functional and cosmetic results than DAPF.

In the absence of carpal valgus, rotation was corrected therefore FPA would not be expected to change. Residual procurvatum and translational deformities were better tolerated than rotational or valgus deformities in these patients, therefore correction may not be necessary. DAPF constructs are recommended for clinical application.