Short-term outcome of lamina-sparing decompression in thoracolumbar spinal tuberculosis.

Abstract

The authors sought to assess the outcomes of lamina-sparing decompression using a posterior-only approach in patients with thoracolumbar spinal tuberculosis (TB). In patients with spinal TB with paraplegia, anterior decompression yields excellent results because it allows direct access to the diseased part of the vertebra, but the anterior approach has related morbidities. Posterior and posterolateral decompression mitigate approach-related morbidities; however, these approaches destabilize the already diseased segment. Lamina-sparing decompression through a posterior-only approach is a modification of posterolateral and anterolateral decompression that allows simultaneous decompression and instrumentation while preserving the posterior healthy bony structure as much as possible. Thirty-five patients with spinal TB underwent lamina-sparing decompression and instrumentation. Outcomes were determined by using a visual analog scale (VAS) and the Oswestry Disability Index (ODI) for functional assessment, the American Spinal Injury Association (ASIA) impairment grade for neurological assessment, blood loss and duration of surgery for surgical outcome assessment, and Cobb angles to measure kyphosis correction. In total, 35 patients (12 men and 23 women) with an average age of 35.8 ± 18.7 (range 4-69) years underwent lamina-sparing decompression. Eight patients had dorsal, 7 had dorsolumbar, 7 had lumbar, 9 had multifocal contiguous, and 4 patients had multifocal noncontiguous spinal TB; 33 patients had paradiscal Pott's spine (tuberculous spondylodiscitis), and 2 had central-type disease. The average preoperative Cobb angle was 28.4° ± 14.9° (range 0°-60°) and the postoperative Cobb angle was 16.3° ± 11.3° (44° to -15°). There was loss of 1.6° ± 1.5° (0°-5°) during 16 months of follow-up. Average blood loss was 526 ± 316 (range 130-1200) ml. Duration of surgery was 228 ± 79.14 (range 60-320) minutes. Level of vertebral instrumentation on average was 0.97 ± 0.8 (range 0-4) vertebra proximal and 1.25 ± 0.75 (0-3) distal to the diseased segment. Neurological recovery during the immediate postoperative period occurred in 23 of 27 patients (85.1%). All patients had recovered at the final follow-up at 16 months. The preoperative ODI score improved from 76.4 ± 17.9 (range 32-100) to 6.74 ± 17.2 (0-60) at 16 months. The preoperative VAS score improved from 7.48 ± 1.16 (6-10) to 0.47 ± 1.94 (0-8). Surgical site infection occurred in 2 patients, and 1 patient had an intraoperative dural tear that was successfully repaired. One patient developed implant loosening at 3 months, which was managed by extended instrumentation. To achieve stability, lamina-sparing decompression allows fixation of lower numbers of vertebrae proximal and distal to the diseased segment. This method has a fair outcome in terms of kyphosis correction, good functional and neurological recovery, shorter surgical duration than conventional methods, and less blood loss.