THE FITS - FITZ INTERVERTEBRAL TRACTION SCREW

摘要

Degenerative lumbosacral stenosis (DLSS) is a syndrome of disc, articular fascet, vertebral and soft-tissue associated dynamic or static compression of the cauda equina and L7 nerve roots. DLSS is the most common cause of compression of the cauda equina and L7 nerve roots in dogs, where disc material, inflammatory tissue or vertebral malformation cause dynamic or static impingement. In clinical reports to date, there is paucity of documentation and measurement of neuroforaminal abaxial impingement, especially with regard to the clinical contribution of exit-zone impingement of the L7 nerve root. Surgical treatment has historically targeted specific components of the disease by means of dorsal laminectomy, annulectomy, nuclear extirpation, fascectectomy, foraminotomy, fascet stabilisation or application of dorsal stabilising implants. Selection criteria for surgical intervention and long-term outcome data have been poorly defined. This is especially relevant where the exit zone of the neuroforamen may be encroached by soft tissue or osseous deformity and where dynamic instability is present. Medium-term recurrence of clinical signs has variably been reported as 18-54.5%. Magnetic Resonance Imaging (MRI) has been validated as a useful interrogationtool and may be superior to Computed Tomography (CT) scan in terms of elucidation of the soft-tissue component of neural encroachment, whilst CT defines well the osseous anatomic boundaries.