Comparison between hemilaminectomy with anulectomy or hemilaminectomy with partial discectomy for the surgical management of thoracolumbar anulus fibrosis protrusion in dogs

Abstract

Objective: To compare the clinical outcome of dogs undergoing a hemilaminectomy with anulectomy or a hemilaminectomy with partial discectomy for treatment of thoracolumbar intervertebral disc protrusion (IVDP). Methods: Medical records from 2006 to 2015 were reviewed. Dogs were included if they had clinical signs and imaging findings consistent with thoracolumbar IVDP and had undergone surgical treatment with a hemilaminectomy with anulectomy or hemilaminectomy with partial discectomy. Outcome data was obtained by accessing medical files, veterinary records and conducting owner questionnaires. Variables compared between the two treatment groups included age, sex, body weight, duration of clinical signs, presence and severity of neurological deficits, MRI findings (number of IVDPs and presence of intra-parenchymal/intra-medullary signal intensity changes), surgical time, perioperative complications, postoperative neurological deterioration and recurrence of clinical signs. Results: The two treatment groups showed no significant differences in signalment, clinical presentation and imaging findings. Significantly fewer dogs undergoing a hemilaminectomy with partial discectomy showed an early postoperative neurological deterioration (P=0·037) and recurrence of clinical signs of thoracolumbar IVDP within 18 months of initial presentation (P=0·019) compared with dogs undergoing a hemilaminectomy with anulectomy. Clinical significance: Hemilaminectomy with partial discectomy for decompression of thoracolumbar IVDP is associated with a reduced rate of postoperative neurological deterioration as well as a reduced rate of recurrence of clinical signs compared to hemilaminectomy with anulectomy.