Anterior cervical corpectomy and fusion versus posterior laminoplasty for the treatment of oppressive myelopathy owing to cervical ossification of posterior longitudinal ligament: a meta-analysis.

Purpose: The purpose of this research is to compare the clinical efficacy, postoperative complication and surgical trauma between anterior cervical corpectomy and fusion versus posterior laminoplasty for the treatment of oppressive myelopathy owing to cervical ossification of the posterior longitudinal ligament (OPLL).

Study Design: Systematic review and meta-analysis.

Methods: An comprehensive search of literature was implemented in three electronic databases (Embase, Pubmed, and the Cochrane library). Randomized or non-randomized controlled studies published since January 1990 to July 2017 that compared anterior cervical corpectomy and fusion (ACCF) versus posterior laminoplasty (LAMP) for the treatment of cervical oppressive myelopathy owing to OPLL were acquired. Exclusion criteria were non-human studies, non-controlled studies, combined anterior and posterior operative approach, the other anterior or posterior approaches involving cervical discectomy and fusion and laminectomy with (or without) instrumented fusion, revision surgeries, and cervical myelopathy caused by cervical spondylotic myelopathy. The quality of the included articles was evaluated according to GRADE. The main outcome measures included: preoperative and postoperative Japanese Orthopedic Association (JOA) score; neuro-functional recovery rate; complication rate; reoperation rate; preoperative and postoperative C2-C7 Cobb angle; operation time and intraoperative blood loss; and subgroup analysis was performed according to the mean preoperative canal occupying ratio (Subgroup A:the mean preoperative canal occupying ratio < 60%, and Subgroup B:the mean preoperative canal occupying ratio ≥ 60%).

Results: A total of 10 studies containing 735 patients were included in this meta-analysis. And all of the selected studies were non-randomized controlled trials with relatively low quality as assessed by GRADE. The results revealed that there was no obvious statistical difference in preoperative JOA score between the ACCF and LAMP groups in both subgroups. Also, in subgroup A (the mean preoperative canal occupying ratio < 60%), no obvious statistical difference was observed in the postoperative JOA score and neurofunctional recovery rate between the ACCF and LAMP groups. But, in subgroup B (the mean preoperative canal occupying ratio ≥ 60%), the ACCF group illustrated obviously higher postoperative JOA score and neurofunctional recovery rate than the LAMP group (P < 0.01, WMD 1.89 [1.50, 2.28] and P < 0.01, WMD 24.40 [20.10, 28.70], respectively). Moreover, the incidence of both complication and reoperation was markedly higher in the ACCF group compared with LAMP group (P < 0.05, OR 1.76 [1.05, 2.97] and P < 0.05, OR 4.63 [1.86, 11.52], respectively). In addition, the preoperative cervical C2-C7 Cobb angle was obviously larger in the LAMP group compared with ACCF group (P < 0.05, WMD - 5.77 [- 9.70, - 1.84]). But no statistically obvious difference was detected in the postoperative cervical C2-C7 Cobb angle between the two groups. Furthermore, the ACCF group showed significantly more operation time as well as blood loss compared with LAMP group (P < 0.01, WMD 111.43 [40.32,182.54], and P < 0.01, WMD 111.32 [61.22, 161.42], respectively).

Conclusion: In summary, when the preoperative canal occupying ratio < 60%, no palpable difference was tested in postoperative JOA score and neurofunctional recovery rate. But, when the preoperative canal occupying ratio ≥ 60% ACCF was associated with better postoperative JOA score and the recovery rate of neurological function compared with LAMP. Synchronously, ACCF in the cure for cervical myelopathy owing to OPLL led to more surgical trauma and more incidence of complication and reoperation. On the other hand, LAMP had gone a diminished postoperative C2-C7 Cobb angle, that might be a cause of relatively higher incidence of postoperative late neurofunctional deterioration. In brief, when the preoperative canal occupying ratio < 60%, LAMP seems to be effective and safe. However, when the preoperative canal occupying ratio ≥ 60%, we prefer to choose ACCF while complications could be controlled by careful manipulation and advanced surgical techniques. No matter which option you choose, benefits and risks ought to be balanced.