Abstract-Text deutsch

OBJECTIVE: Muscle-preserving selective laminectomy (MSL) is an alternative to conventional decompression surgery in patients with degenerative cervical myelopathy (DCM). It is less invasive, preserves the extensor musculature, and maintains the range of motion of the cervical spine. Therefore, at our institution, the preferred treatment for DCM has changed from anterior decompression and fusion (ADF): anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF), towards MSL. Our aim was to evaluate surgical outcomes before and after this paradigm shift with patient-reported outcome measures (PROMs), complications, reoperations and cost-effectiveness.

METHODS: This study was a retrospective register-based cohort study. All patients with subaxial DCM who underwent ADF or MSL at our institution from 2008 to 2019 were reviewed. Using analysis of covariance (ANCOVA), changes in PROMs from baseline to the 2-year follow-up were compared between the two groups, adjusting for clinicodemographic parameters, baseline PROMs, number of decompressed levels, and magnetic resonance imaging (MRI) measurements (C2-7 Cobb, C2-7 SVA, modified K-line interval). The PROMs, including the European Myelopathy Score (EMS), the Neck Disability Index (NDI), and the European Quality of Life-5 Dimension Questionnaire (EQ-5D), were collected from the national Swedish Spine Register. Complications, reoperations, and in-hospital treatment costs were also compared between the two groups.

RESULTS: Ninety patients (mean age 60.7 years, 51 men [57%]) were included in the ADF group, and 63 patients (mean age 68.8 years, 41 men [65%]) in the MSL group. The ADF and MSL groups presented similar PROMs at baseline. The preoperative MRIs presented similar C2-7 Cobb angles (10.7 [ADF] versus 14.1 [MSL], p=0.12) and modified K-line intervals (4.08 versus 4.88, p=0.07), but different C2-7 SVA values (16.2 versus 19.3, p=0.04). The comparison of ANCOVA-adjusted mean changes in PROMs from baseline to the 2-year follow-up presented no significant differences between the groups (EMS: p=0.901, NDI: p=0.639, EQ-5D: 0.378, EQ-5D health: p=0.418). The overall complication rate was twice as high in the ADF group (22.2% versus 9.5%, p=0.049), while the reoperation rate was comparable (16.7% versus 7.9%, p=0.146). The average in-hospital treatment cost per patient was 6,870 USD for MSL, 7,737 USD for ACDF, and 14,953 USD for ACCF.

CONCLUSIONS: MSL provides similar PROMs after 2 years, a significantly lower complication rate, and better cost-effectiveness compared with ADF.

Abstract-Text englisch

OBJECTIVE: Muscle-preserving selective laminectomy (MSL) is an alternative to conventional decompression surgery in patients with degenerative cervical myelopathy (DCM). It is less invasive, preserves the extensor musculature, and maintains the range of motion of the cervical spine. Therefore, at our institution, the preferred treatment for DCM has changed from anterior decompression and fusion (ADF): anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF), towards MSL. Our aim was to evaluate surgical outcomes before and after this paradigm shift with patient-reported outcome measures (PROMs), complications, reoperations and cost-effectiveness.

METHODS: This study was a retrospective register-based cohort study. All patients with subaxial DCM who underwent ADF or MSL at our institution from 2008 to 2019 were reviewed. Using analysis of covariance (ANCOVA), changes in PROMs from baseline to the 2-year follow-up were compared between the two groups, adjusting for clinicodemographic parameters, baseline PROMs, number of decompressed levels, and magnetic resonance imaging (MRI) measurements (C2-7 Cobb, C2-7 SVA, modified K-line interval). The PROMs, including the European Myelopathy Score (EMS), the Neck Disability Index (NDI), and the European Quality of Life-5 Dimension Questionnaire (EQ-5D), were collected from the national Swedish Spine Register. Complications, reoperations, and in-hospital treatment costs were also compared between the two groups.

RESULTS: Ninety patients (mean age 60.7 years, 51 men [57%]) were included in the ADF group, and 63 patients (mean age 68.8 years, 41 men [65%]) in the MSL group. The ADF and MSL groups presented similar PROMs at baseline. The preoperative MRIs presented similar C2-7 Cobb angles (10.7 [ADF] versus 14.1 [MSL], p=0.12) and modified K-line intervals (4.08 versus 4.88, p=0.07), but different C2-7 SVA values (16.2 versus 19.3, p=0.04). The comparison of ANCOVA-adjusted mean changes in PROMs from baseline to the 2-year follow-up presented no significant differences between the groups (EMS: p=0.901, NDI: p=0.639, EQ-5D: 0.378, EQ-5D health: p=0.418). The overall complication rate was twice as high in the ADF group (22.2% versus 9.5%, p=0.049), while the reoperation rate was comparable (16.7% versus 7.9%, p=0.146). The average in-hospital treatment cost per patient was 6,870 USD for MSL, 7,737 USD for ACDF, and 14,953 USD for ACCF.

CONCLUSIONS: MSL provides similar PROMs after 2 years, a significantly lower complication rate, and better cost-effectiveness compared with ADF.