Residual deformity of the spinal canal in patients with traumatic paraplegia and secondary changes of the spinal cord

Introduction: The effect of spinal deformity with posttraumatic kyphosis an d stenosis of the spinal canal in producing secondary changes of the spinal cord has been discussed for quite some time. Since the advent of magnetic resonance imaging (MRI), 20 40% of patients with posttraumatic paraplegia a re found to develop hydromyelia. Purpose of our study: To evaluate the influence of residual spinal deformit y, defined by the extent of the posttraumatic kyphosis and stenosis, in the development of posttraumatic hydromyelia. Material and methods: Two hundred and seven cases of traumatic paraplegia w ith MRI follow-up were reviewed retrospectively. A minimum of 3 years durat ion between trauma and MRI study was required (mean 10.6 years [3.2 - 38.3] ). For statistical analysis two groups of patients were formed: with hydrom yelia and without hydromyelia. After healing of the fracture, the extent of the kyphosis and stenosis, as well as the characteristics of the paraplegi a were noted. Results: We found that 53 patients had hydromyelia. A highly significant co rrelation was found for the extent of spinal stenosis and the amount of kyp hosis. Cluster analysis indicated that patients with more than 15 degrees o f posttraumatic kyphosis and more than 25% of stenosis were twice as likely to develop hydromyelia. The level of the lesion and the remaining neurolog ical function was not proven to have any influence towards the development of hydromyelia. Conclusions: These results support the idea that chronic mechanical stress to the spinal cord increases the risk for the development of hydromyelia. S urgical reconstruction should be considered for all patients to prevent sec ondary changes of the spinal cord.