Effect of durotomy in dogs with thoracolumbar disc herniation and without deep pain perception in the hind limbs.

OBJECTIVE: To determine the effectiveness of durotomy as an adjunct to surgical decompression in dogs with thoracolumbar intervertebral disc herniation (TL-IVDH) and loss of deep pain perception (DPP) in the hind limbs. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n = 116) with TL-IVDH and loss of DPP treated with hemilaminectomy. METHODS: Signalment, surgical site, recovery rate, incidence of progressive myelomalacia (PMM), time elapsed from onset of paraplegia of the hind limbs to surgery (TPS), and the length of area of hyperintensity of the spinal cord on magnetic resonance T2-weighted images compared with L2 vertebral body length (LHT2) were compared between dogs treated with hemilaminectomy alone and those treated with adjunct durotomy. Multivariate logistic regression analyses were used to test the association between outcomes and the external view of the spinal cord parenchyma after durotomy. RESULTS: The percentage of dogs regaining ambulation was greater when durotomy was performed (56.9%) than when dogs were treated with hemilaminectomy alone (38.5%; P = .04). In the hemilaminectomy group, 14 dogs died of suspected PMM, while no PMM was detected in the durotomy group. Durotomy, breed, surgical site, and LHT2 influenced recovery. No association was detected between age, sex, body weight, and TPS and recovery. CONCLUSION: Performing a durotomy in combination with decompression improved the return to function and prevented PMM in our clinical setting. CLINICAL SIGNIFICANCE: Surgeons should consider durotomy in dogs with TL-IVDH and loss of DPP in hind limbs to improve surgical outcome.