Rate of Conversion to Fusion following Cervical Laminectomy versus Laminoplasty: A Retrospective Analysis of 4,406 Patients

Introduction: The theoretical benefit of a laminoplasty is to preserve motion while reducing risk of postoperative kyphosis associated with cervical laminectomies. However, there is limited data comparing outcomes between cervical laminectomy without fusion and cervical laminoplasty.
The purpose of this study was to compare the rate of conversion to cervical fusion between patients that received cervical laminectomy and cervical laminoplasty for degenerative cervical disease.

Methods: The PearlDiver database for years 2010 to 2021 was queried for patients who received either a posterior cervical laminectomy or a cervical laminoplasty for a diagnosis of degenerative cervical disease. Multivariable regression analysis was performed to identify variables associated with conversion to fusion. A matched analysis was performed using the significant variables. Rates of conversion to cervical fusion were determined for each cohort for 2-years, 5-years, and 10-years after surgery. The rates were compared using Chi-square test. Survival analysis was performed.

Results: A total of 4,406 patients (Laminectomy: 2,258; Laminoplasty: 2,148) were included in this study. In the multivariable logistic regression analysis, age and obesity were significant variables. In the matched analysis, the rate of conversion to fusion for laminectomy at 2-years, 5-years, and 10-years were 3.2%, 5.0%, and 5.7%, respectively. The rate of conversion to fusion for laminoplasty at 2-years, 5-years, and 10-years were 2.2%, 3.2%, and 3.5%, respectively. There was no significant difference between the two groups at 2-years after surgery. Cervical laminectomy patients had a higher rate of conversion to fusion than cervical laminoplasty at 5-years and 10-years after surgery.

Conclusion : In patients with degenerative cervical disease, cervical laminectomy had a significantly higher rate of conversion to cervical fusion than cervical laminoplasty at 5-years and 10-years post-surgery. This is the largest study comparing laminectomy to laminoplasty to date.