Outcome of traumatic intervertebral disk lesions after stabilization by internal fixator

The optimal treatment of intervertebral disk lesions accompanying thoracolumbar fractures remains controversial. To evaluate short- and medium-term progression of intervertebral disk lesions accompanying vertebral fractures, MRI scans obtained after trauma were compared with scans obtained at an average follow-up of 1 year, by means of our clinically useful classification of traumatic intervertebral disk lesions.

MRI scans of 54 disks in patients with trauma-induced single-level thoracolumbar fractures were analyzed retrospectively. All patients underwent posterior stabilization using a titanium internal fixator. Exclusion criteria were malignant vertebral collapse, spondylodiskitis, osteoporotic fractures, and degenerative disk disease in the uninjured disks. Morphologic changes and signal alterations of the adjacent disks were compared using routine MRI scans obtained after trauma and at an average follow-up of 1 year. Disks were divided according to their signals into four categories, from grade 0 to grade 3.

Of the disks studied after trauma (n = 54), 27.8% were determined to be grade 0, 31.5% were grade 2, and 40.7% were grade 3. In the follow-up examination, MRI detected grade 0 in 13% of disks. Hence, more than 50% of the disks with grade 0 after trauma changed into grade 2 lesions, resulting in 46.3% grade 2 lesions. Grade 3 disk lesions (40.7%) remained the same without any sign of recovery.

In the current study, we found progressive disk degradation and creeping in instrumented and nonfused segments in thoracolumbar fractures. For further validation, randomized controlled long-term outcome investigations seem mandatory as the next step in future clinical research.