The vertebral column traumatic injuries are very common in small animal practice. Usually produced by road accidents or others, like falls, gunshots, bites and colisions againts fixed obstacles.
In these traumatisms is essential to check likely concomitant injuries in spinal nervous structures which produce different degrees of neurologic disorders. A proper neurologic examination is crucial in order to set up the prognosis and possibly treatment, keeping in mind that with deeph sensitivity there are still recovery expectations.
The aim of spinal traumatic injury treatment is either nervous structures descompresion, which severity is dictated by the neurologic examination and the myelographic exploration or achieve an adecuate stability to prevent the outcoming damages, wich stability is determained by the compartments theory.
The vertebral body and fibrous annulus produce from 60% to 70% of the spinal stability. The articular facets involve the 10%-20%, while muscles and dorsal and ventral longitudinal ligaments provide the remaining 10% (Shires). That means the ventral compartments injuries, those which involve the vertebral body or those affecting both compartments have to be treated ventraly.
At toracolumbar and lumbar level it is a challange to achieve a good stability in spinal fractures because of the difficulty to combine several implants given to the proximity of vital structures (spinal cord, aorta, etc) and also to obtain an stable technique with enough guaranties. It should be kept in mind that the simultaneus use of bone plates in vertebral body (ventral) and spinous apofisis (dorsal) is the technique wich provides the best stability and still provides a three times less stability than the biomechaniques forces originates at fracture level.
The technique described by Dr. David Wise is an easy one, whithout specific materials, which combines dorsal and ventral fixation by means of a modification of the segmentary dorsal stability and provides a proper stability in most patients.
The technique itself consists in placing a double wire ventral to the vertebral body, caudal to the lesion and it's fixation with two Kirscher wire onto the transverse apofisis, acording to the classic intersegmentary fixation, being the main step, placing the ventral wire at the vertebral body without damaging closing structures, aorta, which is avoided checking the bilateral pulse just when tightening the wire.
Dr. Wise reports two satisfactorily resolved cases by this technique. Also using it, we have achieved hopefully results in 14 patients. As complication in some cases we have found the cranial assembly loosening. It was resolved by craneal fixation with a wire around the vertebral body or fixed to the transverses apofisis, so that a higher stability is achieved.
Summary: with Dr. Wise technique, which consists in the modification of the segmentary fixation added to a ventral wire assembly around the vertebral body at toracolumbar, lumbar and lumbosacro level we have achieved satisfactory results with easy application and without special materials, although it must be taken into account the risk of producing severe injuries in vital visceres which can be avoided by an adequate use of orthopaedic techniques in wires application.
References
1. David Wise. "A novel technique for stabilizing vertebral fractures and luxations in dogs." Veterinary Medicine. December 1999: 1033-1042.
2. Shires P. K. Spinal Fractures. Small Animal Orthopedics . M. L. Olmsted. Mosby, M.O. 1995 pp 183-190.
3. McKee, Malcon. The Spine. Manual of Small Animal Fracture Repair and Management. B.S.A.W.A. pp 133-160.
4. Wheeler. Small Animal Spinal Disorders. Mosby, pp 171-191.
5. Oliver, Hoerleing, Mayhew. Veterinary Neurology, Saunders, pp 416-441.