Effectiveness of laminectomy with fusion and laminectomy alone in degenerative cervical myelopathy

Purpose The effectiveness of laminectomy with fusion and laminectomy alone in degenerative cervical myelopathy was compared. Methods Individuals treated with laminectomy with fusion or laminectomy alone at or below the second cervical vertebra were identified in the Swedish spine registry. 66 individuals treated with laminectomy and instrumented fusion were age matched to 132 individuals treated with laminectomy alone. The European Myelopathy Scale (EMS), the Neck Disability Index (NDI), the Numeric Rating Scale (NRS) for neck pain and the EQ-5D index were available at baseline, and at 1 and 2 year follow-ups. Statistical analyses were performed with Mann-Whitney U tests and paired T tests. Effect sizes were described with Cohen's D. Results Data at baseline did not differ significantly between the groups with the exception of a longer laminectomy in the fusion group (4.2 vs 3.4 vertebras; p < 0.001). Both groups improved EMS, NDI, NRS and EQ-5D from baseline to 1 year (p <= 0.011), with no additional improvement between 1 and 2 years (all p >= 0.09). Effect sizes for change from baseline were small to medium in both groups. At 2 years the laminectomy with fusion group and the laminectomy alone group had a median (25th;75th percentile) EMS of 13 (11;13) and 13 (11;15) (p = 0.77), NDI of 39 (24;54) and 27 (10;41) (p = 0.045), NRS of 4 (1;2) and 2 (0;5) (p = 0.048), and EQ-5D index of 0.67 (0.25;0.73) and 0.66 (0.17;0.76) (p = 0.96). Conclusion The results of this study suggest similar effectiveness of laminectomy with instrumented fusion and laminectomy alone in degenerative cervical myelopathy