Laminectomy alone versus laminectomy with fusion for degenerative cervical myelopathy: a long-term study of a national cohort

Eddie De Dios,Anna Macdowall,Lars Lindhagen,Robert F Heary

doi:10.1007/s00586-021-07067-w

Abstract

PurposeTo compare patient-reported 5-year clinical outcomes between laminectomy alone versus laminectomy with instrumented fusion in patients with degenerative cervical myelopathy in a population-based cohort.MethodsAll patients in the national Swedish Spine Register (Swespine) from January 2006 until March 2019, with degenerative cervical myelopathy, were assessed. Multiple imputation and propensity score matching based on clinicodemographic and radiographic parameters were used to compare patients treated with laminectomy alone with patients treated with laminectomy plus posterior-lateral instrumented fusion. The primary outcome measure was the European Myelopathy Score, a validated patient-reported outcome measure. The scale ranges from 5 to 18, with lower scores reflecting more severe myelopathy.ResultsAmong 967 eligible patients, 717 (74%) patients were included. Laminectomy alone was performed on 412 patients (mean age 68 years; 149 women [36%]), whereas instrumented fusion was added for 305 patients (mean age 68 years; 119 women [39%]). After imputation, the propensity for smoking, worse myelopathy scores, spondylolisthesis, and kyphosis was slightly higher in the fusion group. After imputation and propensity score matching, there were on average 212 pairs patients with a 5-year follow-up in each group. There were no important differences in patient-reported clinical outcomes between the methods after 5 years. Due to longer hospitalization times and implant-related costs, the mean cost increase per instrumented patient was approximately $4700 US.ConclusionsInstrumented fusions generated higher costs and were not associated with superior long-term clinical outcomes. These findings are based on a national cohort and can thus be regarded as generalizable.

Highlights

Degenerative cervical myelopathy is a leading cause of spinal cord dysfunction in adults worldwide
Among 967 eligible patients, 155 (27%) of 567 patients were excluded in the laminectomy-alone group, and 95 (24%) of 400 patients were excluded in the fusion group
Sex ratio, age, body mass index (BMI), and the number of compressed levels were comparable between the groups, with slightly worse smoking status, baseline European Myelopathy Score (EMS), and baseline Neck Disability Index (NDI) score in the fusion group

Summary

Introduction

Degenerative cervical myelopathy is a leading cause of spinal cord dysfunction in adults worldwide. Previous research has estimated that degenerative spine disease accounts for 59% of non-traumatic spinal cord injury in Japan, 54% in the United States, and 31% in Europe. The decompression of the spinal cord can be achieved with both anterior and posterior approaches, and several surgical techniques have been proposed, including discectomy with fusion, corpectomy with fusion, laminectomy alone, laminectomy with fusion, and laminoplasty [3]. Following reports of post-laminectomy kyphosis in the 1970s/1980s [8], conventional thinking has favored including a prophylactic posterior-lateral instrumented fusion when there are signs of ‘instability’ [9]; there is no widely agreed upon definition of ‘instability’ in the degenerated cervical spine. The decision to fuse is mainly based on surgeon preference [10]

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