Clinical and radiographic evaluation of posterior surgical correction for the treatment of moderate to severe post-tuberculosis kyphosis in 36 cases with a minimum 2-year follow-up

Abstract

The object of this study was to compare the clinical and radiographic outcomes of 36 patients with posttuberculosis kyphosis who underwent one of two types of osteotomy. Each patient underwent single-stage correction via a posterior surgical approach. A modified pedicle subtraction osteotomy (mPSO) was performed when the kyphotic deformity was less than 70° (7 cases), whereas a posterior vertebral column resection (VCR) was performed when the kyphotic deformity exceeded 70° (29 cases). Full-length standing radiographs were obtained before surgery and at follow-up visits. These images were used to measure the kyphosis angle; sagittal alignment of the lumbar, thoracic, and cervical regions; and sagittal balance of the spine. Back pain was rated using the visual analog scale (VAS), and neurological function was classified based on the American Spinal Injury Association (ASIA) grading system. Each patient's overall satisfaction with surgical treatment was measured with the Patient Satisfaction Index. For purposes of comparison, patients were studied in 2 groups based on the region of their kyphotic apex. Half of the cohort had apical kyphosis in the lower thoracic spine or thoracolumbar junction (TL group). Using both radiographic and clinical assessments, the authors compared this group with the other half of the patients who had apical kyphosis in the upper to mid thoracic spine (MT group). The cohort included 15 males and 21 females, with an average age of 34 years at the time of surgery. The minimum follow-up was 24 months, and the mean follow-up was 31 months. Following surgery, kyphosis across the treated segments was reduced by an average of 60°. Lumbar lordosis also improved by an average of 24°, and thoracic kyphosis improved by an average of 20°. Both back pain and neurological function improved after surgical treatment. There was a 67% improvement in VAS scores, and 13 of the 36 patients had improvement in their ASIA grade. The 2 surgical procedures used for deformity correction (mPSO and VCR) demonstrated comparable radiographic and clinical results. Note, however, that differences were found in both radiographic and clinical outcomes in comparing patients who had lower thoracic or thoracolumbar (TL group) versus upper to midthoracic (MT group) apical kyphosis. Posterior tubercular kyphosis can be effectively improved through corrective surgery, and deformity correction can be accompanied by improvement in clinical symptoms. When appropriately selected, both the mPSO and the VCR can be expected to yield satisfactory reduction of post-tuberculosis kyphotic deformities. Differences in radiographic and clinical outcomes should be anticipated, however, when treating such deformities in different regions of the spine.