Isolated involvement of the posterior elements in spinal tuberculosis: a review of twenty-four cases.

BACKGROUND

The literature on tuberculosis of the posterior spinal elements without involvement of the vertebral body is scarce. In this study we report our experience with twenty-four cases of neural arch tuberculosis that were treated at our center.

METHODS

We performed a retrospective review of the clinical and radiographic data of twenty-four consecutive patients who had tuberculosis of the posterior spinal elements with total sparing of the vertebral bodies and intervertebral disc space. We categorized the patients into two groups on the basis of the clinical and radiographic evaluation. The patients who had rapid onset weakness of the lower limbs or pyramidal signs or who showed evidence of epidural abscess underwent emergency decompressive laminectomy (Group A). Patients who had pyomyositis of the posterior spinal muscles without any neurological deficit, pyramidal signs, or epidural abscess were managed with antitubercular therapy alone (Group B).

RESULTS

The common presenting features were spastic limb weakness and back pain. The majority of the patients had involvement of the thoracic spine. Epidural abscess, erosion of lamina, and pyomyositis of posterior spinal muscles were common imaging findings. Group A consisted of nineteen patients and Group B consisted of five patients. The mean period of follow-up was 16.9 months (range, nine to sixty months). Patients in Group A had a poorer outcome than those in Group B. Thirteen of the nineteen patients in Group A improved to become independent in the activities of daily living, with complete neurological recovery in eight patients and partial recovery in five patients. Six of the nineteen patients continued to have spastic paraplegia and were wheelchair-dependent. All of the patients in Group B remained neurologically intact during the follow-up period. None of the patients had recurrence of the disease or developed anterior element involvement or kyphotic deformity during the follow-up period.

CONCLUSIONS

Neural arch tuberculosis is often missed at the time of initial presentation. In association with epidural abscess, it leads to rapid neurological deterioration. This atypical picture of spinal tuberculosis showed a high rate of neurological deficit at the time of initial presentation for medical care.