[Neurological complications of surgery for spinal deformities]

The aim of this study was to precisely analyse the physio-pathogenic mechanisms, bring to light the risk factors, and find a more practical way of proceeding in spinal surgery. Out of 667 spinal instrumentation surgical operations carried out between 1980-1989, we found 33 (4.8 per cent) neurological complications and have divided them into 2 groups: 7 peripheral complications, 26 cord and central complications. After further analysis, especially of the cord complications (2.5 per cent), we were able to pick out the factors which influence the rate of neurological complications and their evolution: secondary aetiology and the kyphotic composition of spinal deformation, and above all the notion of cord at risk. The delay of cord complications and especially the relation between the severity of the neurological syndrome and its evolution is extremely important. Somesthesic evoked potential monitoring confirmed that per operative diagnosis of a cord injury is possible. The steps to take when confronted with neurological complications, depend on the results of many examinations: pre and post-operative neurological evaluations electrophysiological exploration of the cord and neuro radiological explorations (myelography, scanner and IRM). This helps to complete aetiology and eliminate mechanical causes, which are the only positive indications of iterative surgery. The problems of instrumentation removal in emergency and the legal-medical aspect brought on by this type of complication are discussed.