Objective: To describe the dorsal laminectomy, annulectomy and distraction stabilization with pins and polymethylmethacrylate technique, its complications and outcome in the management of canine degenerative lumbosacral stenosis. To determine pre- and post-surgical foraminal width and vertebral step changes.
Study design: Multi-institutional retrospective clinical study.
Methods: Medical records (2005-2020) of dogs treated (n = 30). Clinical signs, Modified Frankel Score, Texas Spinal Cord Injury Score, pain score (dorsal palpation of spine, tail dorsiflexion), imaging findings and complications were retrieved pre-operatively, perioperatively and at long-term follow-up.
Results: The most common presurgical imaging findings were disc protrusion (24/25) and sclerosis of the caudal end-plate of L7 (23/30). On short- to long-term assessment 18 out of 21 dogs exhibited clinical improvement and all exhibited improved pain scores (p < 0.0001). Catastrophic complications occurred in 3 dogs, and major complications occurred in 5, of which 3 required additional surgery. Mean lumbosacral step defect reduced 60% (1.8 mm ± 2.5 mm pre-surgery to 0.7mm ± 0.9mm post-surgery, p = 0.1585). Mean foraminal width significantly increased 50% long-term (3.3 mm ± 1.0 mm pre-surgery to 5.0 mm ± 0.9 mm post-surgery, p < 0.0001).
Clinical significance: Dorsal laminectomy, annulectomy and distraction stabilization is a complex procedure which can significantly increase foraminal width, reduce pain and improve gait characteristics in dogs in the short- to long-term, and should be performed by surgeons experienced in lumbosacral pin placement.