Factors associated with cervical instability requiring fusion after cervical laminectomy for intradural tumor resection

Object. The indications remain unclear for fusion at the time of cervical laminectomy for intradural tumor resection. To identify patients who may benefit from initial fusion, the authors assessed clinical, radiological/imaging, and operative factors associated with subsequent symptomatic cervical instability requiring fusion after cervical laminectomy for intradural tumor resection. Methods. The authors reviewed 10 years of data obtained in patients who underwent cervical laminectomy without fusion for intradural tumor resection and who had normal spinal stability and alignment preoperatively. The association of pre- and intraoperative variables with the subsequent need for fusion for progressive symptomatic cervical instability was assessed using logistic regression analysis, and percentages were compared using Fisher exact tests when appropriate. Results. Thirty-two patients (mean age 41 ± 17 years) underwent cervical laminectomy without fusion for resection of an intradural tumor (18 intramedullary and 14 extramedullary). Each increasing number of laminectomies performed was associated with a 3.1-fold increase in the likelihood of subsequent vertebral instability (odds ratio 3.114, 95% confidence interval 1.207-8.034, p = 0.02). At a mean follow-up interval of 25.2 months, 33% (4 of 12) of the patients who had undergone a ≥ 3-level laminectomy required subsequent fusion compared with 5% (1 of 20) who had undergone a ≤ 2-level laminectomy (p = 0.03). Four (36%) of 11 patients initially presenting with myelopathic motor disturbance required subsequent fusion compared with 1 (5%) of 21 presenting initially with myelopathic sensory or radicular symptoms (p = 0.02). Age, the presence of a syrinx, intramedullary tumor, C-2 laminectomy, C-7 laminectomy, and laminoplasty were not associated with subsequent symptomatic instability requiring fusion. Conclusions. In the authors' experience with intradural cervical tumor resection, patients presenting with myelopathic motor symptoms or those undergoing a ≥ 3-level cervical laminectomy had an increased likelihood of developing subsequent symptomatic instability requiring fusion. A ≥ 3-level laminectomy with myelopathic motor symptoms may herald patients most likely to benefit from cervical fusion at the time of tumor resection.