Late-onset neurological deficits induced by proximal adjacent segment degeneration related to severe post-tuberculous kyphotic deformities of the spine: a series of 7 cases and surgical correction concept.

Objective: Late-onset neurological deficits are a rare complication of spinal tuberculosis that may be caused by proximal adjacent segment degeneration (ASD) above the kyphus. The objective of this study was to report several cases of neurological deficits due to proximal ASD in patients with post-tuberculous kyphotic deformity and discuss the characteristics of the authors' corrective surgical technique.

Methods: The inclusion criteria in this study were severe angular kyphosis due to a post-tuberculous kyphotic deformity and a late-onset neurological deficit. The cause of these deficits was related to a lesion in the proximal cephalad portion of the kyphotic deformity. Surgical intervention, including decompression and compromised restoration of the sagittal imbalance, was performed in all patients. Preoperative surgical planning with a radiological evaluation included CT, plain radiograph, and MRI studies. Clinical outcomes were evaluated using the American Spinal Injury Association Impairment Scale and the Oswestry Disability Index (ODI).

Results: The main goal of our surgical technique was the correction of sagittal malalignment by positioning the patient's head above the kyphotic deformity on the sagittal plane, excluding aggressive osteotomy. The neurological symptoms showed immediate improvements postoperatively, except in 1 patient. Compared to the preoperative value of 66.9, the mean ODI score improved to 42.6 at the final follow-up for all patients. Preoperatively, the mean values of the angles of deformity and the sagittal vertical axis were 99.7° and 157.7 mm, respectively, and decreased to 75.3° and 46.0 mm, respectively, at the final follow-up. No major complications were observed, and the patients' self-satisfaction was high with respect to both cosmetic and functional outcomes.

Conclusions: Clinicians should be aware of the degeneration of the vertebrae above the kyphotic segment in patients with post-tuberculosis deformity. Successful neurological recovery and compromised sagittal balance could be obtained by using our "head on kyphus" surgical concept.