Surgical Treatment of Lumbosacral Foraminal Stenosis Using a Lateral Approach in Twenty Dogs with Degenerative Lumbosacral Stenosis

Abstract

To describe clinical signs, magnetic resonance imaging (MRI) and surgical findings using a lateral approach to the lumbosacral intervertebral foramen and to evaluate clinical outcomes in dogs with or without concurrent dorsal decompression and annulectomy. Retrospective study. Dogs (n=20) with degenerative lumbosacral stenosis (DLSS). Medical records (2002-2006) of dogs that had lumbosacral lateral foraminotomy alone or in combination with dorsal decompression were reviewed. Degree of dysfunction was assessed separately for each pelvic limb; dogs with unilateral signs were included in group A, those with bilateral signs in group B. Retrieved data were: signalment, history, neurologic status on admission, 3 days, 6 weeks, and 6 months postoperatively, duration of clinical signs, results of MRI, surgical site(s), intraoperative findings, and outcome. Based on the clinical and MRI findings unilateral foraminotomy was performed in 8 dogs, bilateral foraminotomy in 1 dog, unilateral foraminotomy with concurrent dorsal decompression in 7 dogs, and bilateral foraminotomy with concomitant dorsal decompression in 4 dogs. Surgery confirmed the presence of foraminal stenosis in all dogs, with osteophyte formation and soft tissue proliferations being the most common lesions. Outcome was good to excellent in 19 dogs and poor in 1 dog. Mean follow-up was 15.2 months (range, 6-42 months). Lateral foraminotomy addresses compressive lesions within exit and middle zones of the lumbosacral foramen. Successful surgical management of DLSS is dependent on recognition and correction of each of the compressive lesions within the lumbosacral junction.