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 and 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 are found to develop hydromyelia. Purpose of our study: To evaluate the influence of residual spinal deformity, 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 with MRI follow-up were reviewed retrospectively. A minimum of 3 years duration 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 hydromyelia and without hydromyelia. After healing of the fracture, the extent of the kyphosis and stenosis, as well as the characteristics of the paraplegia were noted. Results: We found that 53 patients had hydromyelia. A highly significant correlation was found for the extent of spinal stenosis and the amount of kyphosis. Cluster analysis indicated that patients with more than 15 degrees of posttraumatic kyphosis and more than 25% of stenosis were twice as likely to develop hydromyelia. The level of the lesion and the remaining neurological 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. Surgical reconstruction should be considered for all patients to prevent secondary changes of the spinal cord.