Residual deformity of the spinal canal in patients witn traumatic paraplegia and secondary changes of the myelon

R Abel

Orthopädische Klinik der Heinrich Heine Universität Düsseldorf

C. Smit, H.J. Gerner

Stiftung Orthopädische Universitätsklinik Heidelberg

T. Meiners

Dept. 1, Werner Wicker Klinik, Bad Wildungen

Introduction:

The effect of a remaining spinal deformity with kyphotic angulation and/ or stenosis of the spinal canal towards secondary changes of the myelon has been discussed for quite a while. Since the advert of the MRI in 20 - 40% of patients with posttraumatic paraplegia hydromyelia, which is the most common secondary change in the myelon, could be diagnosed. While some centers try to perform an anatomic reconstruction of the spinal ,canal - even if the fracture has already healed and no neurologic recovery was noted, others tend to be more conservative because they feel that the potential benefit of major spinal surgery does not outweight the risk of these procedures in this group of patients. The purpose of our study is to evaluate the influence of residual spinal deformity, defined by the extend of the kyphotic angulation and the extend of the posttraumatic stenosis of the spinal canal, towards the developement of posttraumatic hydromyelia.

Material and methods:

In a retrospective study 201 cases of traumatic paraplegia witn MRI-follow-up were reviewed. A minimum of 3 years interval between the accident and the MRI study was required (Mean 10.6 years [3.2 - 38.3]). For statistical analysis a group of patients with hydromyelia and a group of patients without hydromyelia was formed. The extend of kyphosis and stenosis after healing of the fracture, as well as the characteristics of the paraplegia were noted.

Results:

We found that 49 patients had developed hydromyelia. A highly significant correlation was found for the extend of narrowing of the spinal canal (p= 0. 0022; T-test) and the amount of the kyphotic angulation in the fracture site (p=0.0045; T-test). The level of the lesion and the remaining neurologic function did not show any significant correlation towards the development of hydromyelia.

Conclusions:

These results support the idea that the spinal canal should be reconstructed in patients with postraumatic neurologic deficit, even if the fracture has already fused, if there is residual spinal deformity. Angulation and narrowing should both be corrected to prevent secondary changes of the myelon and their hazards.