Does kyphosis in healed subaxial cervical spine tuberculosis equate to a poor functional outcome?

Abstract

Introduction: Tuberculosis (TB) of the subaxial cervical spine has a high percentage of morbidity. It accounts for about 10% of cases with the major concerns being quadriparesis and localized kyphosis. Aim: The study aims to provide an insight in the management of subaxial cervical spine TB treated by multiple modalities. Materials and Methods: A retrospective analysis of 91 patients with subaxial cervical (C3-C7) TB was performed. Neurology was assessed by Nurick's grading and pain using the visual analog scale (VAS) (in mm). Radiological evaluation was done with standard anteroposterior and lateral view of the cervical spine at presentation and 3 monthly intervals after intervention. Magnetic resonance imaging was done in all patients. Angle of kyphosis (K angle) was calculated from plain radiographs. Results: Mean age of the patients was 31.5 years. Neurological status was Nurick's Grade 5 in 8, Grade 4 in 15, Grade 3 in 28, Grade 2 in 22, Grade 1 in 7, and further 11 had Nurick's Grade 0. Operative intervention was either anterior, or posterior, or a combination of both depending on extent of vertebral destruction. All patients with Nurick's 5 and 4 improved to 3 or less at final follow-up. The kyphosis angle at presentation ranged from 2° to 58° of with an average kyphosis of 16.05°. The postoperative kyphosis was graded as mild (loss of lordosis to 10° kyphosis), moderate (10°-30°), and severe (>30°). Ten patients had mild kyphosis and 6 patients had moderate kyphosis. Mean VAS score at presentation was 45.5 mm which improved to 14.48 mm at follow-up. Patients with mild and moderate kyphosis remained asymptomatic till the last follow-up. Conclusion: Healing of subaxial cervical TB in kyphosis does not necessitate a poor clinical outcome as most patients remain asymptomatic.