Decompressive Laminectomy with Fusion as an Alternative to Multilevel Discectomy/corpectomy in Cervical Stenotic Spondylotic Myelopathy

Introduction: Multilevel cervical stenotic spondylotic myelopathy (CSM) is currently frequently treated via anterior multilevel discectomy/corpectomy, although modern magnetic resonance imaging (MRI) technology makes posterior decompressive laminectomy with fusion an important alternative. We sought to study the effects of decompressive laminectomy and lateral mass fusion on the posterior migration of the spinal cord in multilevel CSM by using pre- and post-operative MRI measurements.

Methods: We retrospectively reviewed the medical records of 89 patients with CSM who underwent cervical laminectomy extending over at least four levels and fusion that were performed at a single institution from January 2000 to January 2020. Statistical analysis involved independent sample tests, paired t-tests, chi-square tests, nonparametric t-tests, and repeated measure ANOVA at the 0.05 level of significance and was performed using PASW Statistics 18.0.

Results: Our cohort was 55.1% male with a median age of 67 years. Pre-operatively, severe stenosis was present in 79.5% patients; anterior and posterior compression were present in 94.9%; CSF spaces were < 1mm anteriorly and posteriorly; mean Kamata measurement was 1.3mm; mean C2-7 Cobb angle was -8*; and, mean minimum C2-7 mK-line interval was 4.9mm. Post-operatively, stenosis was resolved in 43.6% patients and mild in 46.2% (p < 0.0001); anterior compression was absent in all patients and posterior compression was present in 2.0% (p < 0.0001); CSF spaces were >1.5mm anteriorly and posteriorly (p < 0.0001); mean Kamata measurement was 0.3mm (p=0.0061); mean C2-7 Cobb angle was -2* (p=0.0011); and, mean minimum C2-7 mK-line interval was 5.6mm (p < 0.0204). Global posterior spinal cord migration for C2-7 was -27mm. Our complication rate was 16.3%.

Conclusion : We demonstrated a significant posterior migration of the spinal cord in all cases of CSM treated with multilevel decompressive laminectomy and lateral mass fusion. We believe that this procedure should assume a more prominent role in the surgical armamentarium for the treatment of CSM.