Role of Additional Coronal Magnetic Resonance Imaging in Decompression and Reconstruction with or without Segment Salvage in Thoracic Spine Tuberculosis

ABSTRACT

STUDY DESIGN: Retrospective and observational study.PURPOSE: The present study aimed to develop guidelines for segment salvage or sacrifice based on the amount and status of the remnant portion of the vertebra as assessed by coronal magnetic resonance imaging (MRI) in addition to sagittal and axial images in thoracic spine tuberculosis (TB).OVERVIEW OF LITERATURE Indications for surgery have not changed significantly since the ‘middle path regimen’ was proposed by Tuli. Goals of modern surgical management of spinal TB include debridement of diseased vertebrae, spinal cord decompression, deformity correction, and spine stabilization. However, the extent of decompression has not been defined previously. Too less decompression will lead to compromised neurological recovery, whereas large extent of decompression is associated with increased surgical morbidity and longer segment to reconstruct.METHODS: Sixty-five patients with thoracic spine TB were divided into two groups (segment salvage/sacrifice) based on the thickness of the subchondral bone and endplate morphology of the vertebra as seen on MRI. The operative procedure in the form of instrumentation with Hartshill loop rectangle and sublaminar wire using the simultaneous anterior posterior approach in lateral position (versatile approach) was performed. The patients were analyzed for postoperative fusion, improvement in kyphosis angle, and followed up for development of complications.RESULTS: This method of deciding the level of fixation and segment salvage based on coronal MRI in addition to the sagittal and axial images provided good result in 64 of 65 patients, except for one patient in the segment sacrifice group who had graft buckling and resultant kyphosis.CONCLUSIONS: For segment salvage, having a clear three-dimensional idea about the viable remnant bone is important. Viable salvaged segment reduces the morbidity of the procedure, length of the construct, and unnecessary debridement without compromising on the neural recovery and fusion rate. Hence, additional cone down coronal cuts must be required when MRI is suggestive for spinal TB because it will help in the decision making.