Ex vivo biomechanical study of hemilaminectomy and pediculectomy in canine thoracolumbar spine

Author(s)

Jaqueline França dos Santos

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2017-07-25

Examining board members

Cassio Ricardo Auada Ferrigno; Asdrubal Falavigna; Márcio Poletto Ferreira; André Luis Selmi; Angelo João Stopiglia

• Advisor: Cassio Ricardo Auada Ferrigno

Abstract

Intervertebral disk disease (IVDD) is extremely common in dogs and typically affects chondrodystrophic breeds. Thoracolumbar IVDD is the most common cause of canine neurological dysfunction. Clinical signs associated with disk protrusion may range from spinal pain to paresis/paraplegia and loss of nociception. Procedures for thoracolumbar spine decompression include hemilaminectomy and pediculectomy. Hemilaminectomy involves removal of articular facets and adjacent pedicular bone; pediculectomy differs from hemilaminectomy in that articular facets are preserved. This study set out to investigate the biomechanical behavior of the canine thoracolumbar spine under flexion and measure destabilizing effects of multiple consecutive unilateral hemilaminectomies and pediculectomies performed at T11 through L2. Test specimens were submitted to five biomechanical tests, as follows: intact segment (control) and following one, two, three and four hemi laminectomies or pediculectomies. Nineteen tests were performed in total (10 in the laminectomy and 9 in the pediculectomy group). Tests were repeated three times and mean angle differences, force values and specimen length calculated. Data were analyzed using the Generalized Estimated Equations (GEE) method and the Bonferroni test for multiple comparisons. Statistical analyzes were performed using SPSS software (v. 20.0); the level of significance was set at 5%. Results revealed significant differences, with higher values reflecting higher numbers of consecutive decompression procedures. However, destabilization promoted by decompression techniques investigated was mild (approximately two degrees), and did not differ significantly between techniques. (AU)

• FAPESP's process: 13/18806-1 - Ex vivo biomechanical study of hemilaminectomy and mini-hemilaminectomy in canine thoracolumbar spine
• Grantee: Jaqueline França dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate