Methods
A MEDLINE review of English-language literature was performed to identify studies comparing ventral multilevel discectomy and fusion with dorsal cervical fusion performed between 2003 and 2013. This time period was chosen to focus on only the most recent studies relevant to current clinical practice. The search terms included ventral cervical fusion, anterior cervical fusion, dorsal cervical fusion, posterior cervical fusion, cervical spondylotic myelopathy, and CSM. A total of 3512 results were retrieved from these searches. Furthermore, references from the identified studies as well as those from other review papers were used to ensure completeness. Studies were excluded if they did not pertain to ventral and dorsal fusion, involved single-level fusions, or if they were animal studies, single case reports, or clinical series with fewer than 10 patients reported, to ensure sufficient statistical power in study conclusions. Patients treated with laminectomy without fusion, and those who underwent laminoplasty procedures were not included because the primary focus of this review was on fusion. Studies were included only if they specifically pertained to clinical outcomes, complication profiles, or financial costs for ventral versus dorsal fusion surgery for CSM. Seven clinical studies were reviewed here.
Articles were further classified according to the level of evidence outlined by Resnick et al., in which studies are categorized into 3 classes. Class I evidence is the highest level, consisting of randomized controlled trials. Class II evidence includes most prospective studies other than randomized controlled trials. Class III studies consist of retrospectively collected data and case series. The level of evidence for the included studies was assessed by 2 independent reviewers (M.D.A. and D.L.), and any disagreement was resolved by reviewer consensus. Data collected from the included studies consisted of study type, patient sample size, specific complications and complication rate, health outcomes measured, types of questionnaires used, follow-up period, and costs.