Introduction: Spinal deformity correction is a demanding realignment of the spine in which neurological monitoring can be used to reduce the risk of neurological deficits related to surgery. The purpose of this study was to assess the pre‐op neurological risk in a consecutive series of spinal deformity patients undergoing correction surgery at one institution.
Methods: This is a retrospective consecutive review of deformity surgical cases at our institution in 2007. Patients were grouped according to diagnosis: Neuromuscular (NM) scoliosis, Sagittal plane deformity, and Scoliosis. There were 301 cases performed (154 pediatric and 126 adult), 281 cases were monitorable. Intra‐operative neurological status was measured with a combination of somatosensory evoked potentials (SSEPs) and/or motor evoked potentials (MEPs).
Results: Comparing each diagnositic criteria and primary vs. revision status, primary NM scoliosis cases had the highest incidence of NMC's (11%). In patients with primarily sagittal plane deformity, NMC's were increased in the setting of larger kyphosis (58°vs. 42°, p<0.05), larger operative change in lumbar lordosis (16.4°vs. 3.9°, p<0.05), and increased blood loss (2.5L vs. 1.6L, p<0.05). Sagittal plane deformity cases had the second highest incidence of NMC's (10.87%). In scoliosis patients, significant increases in NMC's were found with larger pre‐operative thoracolumbar/lumbar curves (50.4°vs. 31.5°, p<0.05) and larger blood loss (1.95L vs. 989mL, p<0.05). However, revision surgery did not appear to significantly affect NMC's in this group (p<0.05). Of the 13 NMC's patients, 3 patients had persistent neurological deficit detected by post‐operative neurological examination; one patient had a resolving foot drop, one patient had motor paraplegia that improved to walker assisted ambulation, and one patient had a partial foot drop that completely resolved.
Conclusion: Primary neuromuscular scoliosis and revision sagittal plane deformities appear to carry greatest risk for NMC's during surgical intervention. Most observed NMC's did not predict a permanent neurological deficit.
Significance: This study may aid surgeons and patients to better assess neurological risks related to spinal deformity surgery.