Open-Door Laminoplasty versus French-Door Laminoplasty in Cervical Compressive Myelopathy: Grading the Evidence through a Meta-Analysis

Research Article

Austin J Anat. 2016; 3(1): 1045.

Open-Door Laminoplasty versus French-Door Laminoplasty in Cervical Compressive Myelopathy: Grading the Evidence through a Meta-Analysis

Yan Li, Wei Guo, Ling-Xiao C, Yu-Lin L, Xiao-Bo W, Guang-Zhi N and Shi-Qing F*

Department of Orthopaedics, Tianjin Medical University General Hospital, China

*Corresponding author: Shi-Qing Feng, Department of Orthopedics, Tianjin Medical University, General Hospital, 154 Anshan Road, Heping District, Tianjin 300052, People’s Republic of China, China

Received: October 12, 2015; Accepted: January 18, 2016; Published: January 22, 2016


Purpose: To compare the clinical outcomes of cervical compressive myelopathy with Open-door laminoplasty or French-door laminoplasty.

Method: We searched electronic databases including PubMed, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar from 1966 to Feb 2015. No language restriction was applied. We used the Cochrane risk of bias tool to evaluate the trial quality. Each reference list was viewed for any ignore studies. Two authors independently extracted data from all eligible studies, including study design, patients’ characteristics, interventions and outcomes. The available data were using random-effects models or fixed-effects with mean differences or stand mean differences for continuous variables. GRADE system was used to assess the level of evidence.

Results: The meta-analyses indicated there was no significant difference in operative time and blood loss between Open-door and French-door group (MD -3.87, 95% CI -10.58 to 2.84, P value=0.26, I2=56%; SMD -0.10, 95% CI – 0.63 to 0.42, P value=0.70, I2=72%, repectively). Open-door laminoplasty significantly decreased Japanese Orthopedic Association (JOA) scores when compared with French-door laminoplasty (MD 0.09, 95% CI 0.59 to 1.39, P value<0.00001, I2=0%).

Conclusion: Considering the results, we could not confirm which laminoplasty is the better one in patients with cervical compressive myelopathy. More high-quality RCTs were needed to test the result.

Keywords: Open-door laminoplasty; French-door laminoplasty; Cervical compressive myelopathy; Meta-analysis; Randomized controlled trial GRADE


Cervical Compressive Myelopathy (CCM) is generally defined as the compression of cervical spinal cord caused by various pathological changes [1]. The principles of treatment for CCM are pain relief recovery of neural functions and preservation of patients’ locomotion. Surgery is still the only effective method to deal with CCM but the selection of surgical methods is still controversial.

Open-door and French-door laminoplasty have their own advantages and disadvantages, but the common purpose of both two is to enlarge the narrowed spinal canal and thus afford the challenge of reactivating the spinal cord. On one hand, Open-door laminoplasty is a standard procedure for the treatment of multiple levels of cervical spondylotic myelopathy. There are several techniques to maintain cervical canal expansion such as the Hirabayashi technique which is the classic open-door laminoplasty that maintains cervical canal expansion by suturing to the contralateral soft tissue [2]. On the other hand, French door laminoplasty consists of a median lamina split followed by a lateral thinning and opening of both hemilaminae. This technique provides satisfied and reliable results in patients with myelopathy due to cervical spondylosis and posterior thickening of the ligament umflavum [3]. In recent researches, scholars have suggested that open-door laminoplasty is superior to French-door laminoplasty, with respect to expansion of the sagittal diameter and because of lower complication rates [4]. Others have suggested that French-door laminoplasty is much more better than opendoor laminoplasty, for patients with multilevel cervical compressive myelopathy as determined by the Medical Outcomes Study 36-item Short- Form Health Survey (SF-36) and have recommended Frenchdoor laminoplasty to minimize postoperative C5 palsy in patients with asymmetrical Ossification Of The Posterior Longitudinal Ligament (OPLL) [5]. The aim of this study was to determine which of these two methods is more effective in terms of clinical and radiologic outcomes.


Criteria for considering studies

We included studies which compared open-door laminoplasty versus french-door laminoplasty in patients with cervical compressive myelopathy.

Studies were considered acceptable for inclusion in the system review if they met the criteria: (1) cervical compressive myelopathy; (2) Open-door laminoplasty compared with French-door laminoplasty.

Trials were excluded if they: (1) were abstracts, letters, or meeting proceedings; (2) had repeated data or did not report outcomes of interest.

Search methods

We searched A med (From 1985 to February 2015), British Nursing Index (From 1985 to February 2015), Embase (From 1974 to February 2015), PubMed (From 1966 to February 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, most recent issue), Google scholar, SIGLE (System for Information on Grey Literature in Europe), the National Technical Information Service, the National Research Register (UK), and the Current Controlled Trials databases. Keywords and MeSH terms including “cervical compressive myelopathy” and “Opendoor laminoplasty” and “French-door laminoplasty” and “unilateral laminoplasty” and “sagittal splitting procedure” were used in the search strategy. We also viewed each reference list for any ignored papers

Selection of studies and assessment of risk of bias in included studies

Two review authors independently made the selection based on title and abstract. Any disagreement between review authors was resolved by discussion. If there were still some debates, a further reviewer and expert was consulted.

We used the Cochrane risk of bias tool to assess risk of bias [6]. The tool included seven domains, which were random sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting and other bias. The judgment for each domain was low risk of bias, high risk of bias, or unclear risk of bias and two authors independently evaluated the risk of studies.

Data extraction and management

Information including the authors, study design, mean age, sample size, study population, outcome measures and follow-up periods were extracted for each included study. For continuous data (e.g. Operation time, Blood loss, Japanese Orthopedic Association (JOA) scores), the Mean Differences (MDs) or Stand Mean Differences (SMDs) with 95%CI was used. We would contact the original author to ask for any missing information as possible as we can. If the paper didn’t support Standard Deviations (SDs) and we couldn’t get data from the author, there were two ways to be used. The first was calculation of the missing SDs if some other data were supplied, for example, MDs, P value and number of patients. The second was manual measurement by graphs presented in article. One review author entered the data into RevMan 5.2, after which another review author checked all values. Meta-analyses were only made when studies were considered to be sufficiently homogeneous and a random-effects model was used for the pooled analysis. We assessed the heterogeneity firstly by observing the overlap of CIs in the forest plots. And then, we used I2 analysis to evaluate the heterogeneity (I2 larger than 50% was considered high heterogeneity).

Assessment of reporting biases and sensitivity analyses

We used a funnel plot to identify possible publication bias. We changed the model and excluded study one by one to test the robustness of the result.

Level of evidence

The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach is to grade the quality of evidence and strength of recommendations [6]. Risk of bias, limitations, the indirectness, the consistency of the results across studies, the precision of the overall estimate across studies and other considerations are six domains of the tool. For each outcome, if further research was very unlikely to change our confidence in the estimate of effect, the quality of the evidence was rated as high; if further research was likely to have an important impact on our confidence in the estimate of effect and may change the estimate, the quality was moderate; if further research was very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate, the quality was low; if the estimate was very uncertain, the quality was very low. The GRADE pro 3.6 software was used to estimate the methodological quality of the evidence in the meta-analysis by two reviewers. If there were disagreements between the two reviewers, a third author would join to discuss and make decisions

We used GRADE pro 3.6 to assess the level of evidence.


Study identification and selection

The PRISMA flow diagram of studies in the article is depicted in (Figure 1). The search was performed on February16th, 2014 and identified 78 references in the primary search and 7 through other sources. After removal of 43 duplicate references, the total amount of references to be screened was 42. After a screening by one author (Li) a total of 8 publications appeared eligible for inclusion, others were not selected for various reasons (e.g. Two studies were case reports and one study was about biomechanics) [7-9]. In total, 5 studies were included in the narrative review and data on 4 of these studies were included in the meta-analysis [10-13].