Outcome of osteoplastic laminotomy for excision of spinal cord tumours.

PURPOSE To evaluate the outcome of osteoplastic laminotomy after excision of primary tumours of the thoracolumbar and lumbar spine. METHODS Records of 10 male and 11 female consecutive patients aged 15 to 57 (mean, 37) years who underwent osteoplastic laminotomy for excision of spinal cord tumours in the thoracolumbar (n=13) and lumbar (n=8) spine were reviewed. After tumour resection, the removed posterior elements were reattached to the superior and inferior processes using anchoring sutures. Pre- and post-operative functional status was retrospectively graded according to the modified McCormick scale. Spinal deformities were classified as sagittal and coronal malalignment, segmental instability, and spondylolisthesis. RESULTS The mean follow-up duration was 43 (range, 12-108) months. The mean number of laminae excised was 1.3 (range, 1-4). At the final follow-up, the modified McCormick scale score improved in 16 patients, remained unchanged in 4, and deteriorated in one. No patient developed any severe complication, recurrence, spondylolisthesis, or aseptic necrosis of grafted laminae. In 2 patients their spinal deformities became worse: one had segmental instability of 17 degrees at L3-4 secondary to non-union of the L3 lamina; the other (with type-I neurofibromatosis and dystrophic deformity) underwent fusion for severe low back pain and lumbar kyphosis and progressive rotational dislocation, despite union of the grafted L2 lamina. CONCLUSIONS Osteoplastic laminotomy preserves the structures that could be important for spinal stability and may reduce the risk of deformities. Anterior strut grafting and posterior fusion may be necessary in neurofibromatosis patients with dystrophic deformities.