Risk factors affecting the outcome of surgery for atlantoaxial subluxation in dogs: 46 cases (1978-1998)

Objective—To identify risk factors for successful surgical management of dogs with atlantoaxial subluxation (AAS). Design—Retrospective study. Animals—46 dogs managed surgically for AAS. Procedure—Age at onset of clinical abnormalities, duration of clinical abnormalities prior to surgery, radiographic appearance of the dens, type (dorsal or ventral procedure) and number (1 or 2) of surgeries performed, grade of postoperative atlantoaxial joint reduction, and neurologic status prior to surgery (preoperative), when dogs were discharged from the hospital (postoperative), and during a follow-up evaluation (final) were obtained from the dogs' medical records. Risk factors for surgical success and degree of neurologic improvement were identified and analyzed for predictive potential. Results—Age at onset of clinical abnormalities ≤ 24 months was significantly associated with greater odds of a successful first surgery and final outcome and a lower postoperative neurologic grade. Duration of clinical abnormalitie...