Residual herniated disc material following hemilaminectomy in chondrodystrophic dogs with thoracolumbar intervertebral disc disease.

Objective: To evaluate the presence of residual disc material within the vertebral canal following hemilaminectomy in chondrodystrophic dogs with thoracolumbar intervertebral disc disease.
Methods: Forty dogs were treated by hemilaminectomy. Computed tomography was performed preoperatively and immediately postoperatively. The vertebral canal height, width, area, and herniated disc material area were measured. Maximum filling percentage (MFP), residual disc percentage (RDP), maximum residual filling percentage (MRFP), and residual filling percentage (RFP) were calculated. Clinical outcome was determined by telephone interviews.
Results: Residual disc material was present in 100% of the dogs. Mean MFP = 55.4% (range 25.9-82.3%; median 56.9%). Mean RDP = 50.3% (range 2.6-155.8%; median 47.9%). Mean MRFP = 30.8% (range 4.9-60%; median 30.1%). Mean RFP = 19.8% (range 4.8-45%; median 19.0%). All dogs were ambulatory with voluntary urination at the long-term follow-up (range: 88-735 days).
Clinical Significance: Residual disc was present in all dogs following hemilaminectomy for intervertebral disc disease. Residual disc was not associated with failure to achieve functional recovery in these cases.