Comparison between Hemilaminectomy with either Anulectomy or Partial Discectomy for Treatment of Thoracolumbar Intervertebral Disc Protrusion in Dogs

Objectives The aim of this study was to compare the clinical outcome of dogs undergoing a hemilaminectomy with anulectomy (HA) or a hemilaminectomy with partial discectomy (HPD) for treatment of thoracolumbar intervertebral disc protrusion. Methods Medical records from 2006 to 2015 were retrospectively reviewed. Dogs were included if they had clinical signs and imaging findings consistent with thoracolumbar intervertebral disc protrusion and had undergone surgical treatment with a HA or HPD. Outcome data were obtained via veterinary records and owner questionnaires. Recorded variables included age, sex, body weight, neurological deficits, surgical time, perioperative complications, postoperative neurological deterioration and recurrence of clinical signs. Results The two treatment groups showed no significant difference in signalment, clinical presentation and imaging findings. However, significant differences were detected in outcome. Early postoperative neurological deterioration was recorded in 16/29 dogs in the HA group and 7/24 dogs in the HPD group (p = 0.037). Sustained clinical improvement for a minimum of 18 months postoperatively was reported in 9/22 dogs in the HA group compared with 17/23 dogs in the HPD group (p = 0.019). Clinical Significance Hemilaminectomy with partial discectomy for decompression of thoracolumbar intervertebral disc protrusion was associated with decreased postoperative neurological deterioration and increased sustained clinical improvement compared with hemilaminectomy with anulectomy.