Does Mesh Cage Subsidence Have Any Effect on Functional Outcome in Spinal Tuberculosis?

Introduction: Occurrence of mesh cage subsidence in patients undergoing anterior column reconstruction following Tuberculosis spine is frequent radiological finding as bone quality of affected vertebrae is poor. This study aims at determining effect of mesh cage subsidence on functional outcome.

Methods: Retrospective demographics of 30 patients of consecutive series in age range 4-60 year were collected with Clinical outcome evaluation using VAS, ODI and ASIA scale. 30 patient having Dorsolumbar tuberculosis with vertebral involvement ranging from 1-6 with mean vertebral level involvement of 2.71, underwent anterior column reconstruction through posterior only approach between 2011-15 were reviewed. Patients were followed at regular intervals of 6 weeks, 12 weeks, 6 months & thereafter on yearly basis. They were evaluated for interbody height loss with subsidence, fusion & segmental angle.

Results: Clinical parameters i.e. VAS & ODI showed improvement in postoperative period which continued to remain same even after subsidence ( < 0.05). Subsidence was categorized as combined anterior + posterior < 5mm; 5 -10mm; >10mm. ODI at follow up was 8.5 ±4.62, 9 ± 2 and 9 ± 4.2 ( = 0.961) respectively & VAS score in above group was 1.3 ± 0.51, 1.5 ± 1.2 & 1.5 ± 0.7 ( = 0.975) respectively. Subsidence was age, spinal level nonspecific.

Conclusion: Study indicates that though Cage subsidence occurs to varying severity due to weakened vertebral bodies, it did not have significant impact on functional outcome in terms of VAS, ODI or radiological evidence of fusion following reconstruction in Spinal tuberculosis.