ObjectiveTo systematically review the efficacy and safety of the anterior and posterior approach for the treatment in ossification of the posterior longitudinal ligament (OPLL) of the cervical spine.MethodsAn electronical search was conducted in PubMed, EMbase, The Cochrane Library, Web of Science, WanFang Data and CNKI from inception to December 2016 to collect studies which compared the anterior cervical approach with posterior approach for OPLL. Two reviewers independently screened literature, extracted data and assessed the risk bias of included studies and then RevMan 5.3 software was used to perform meta-analysis.ResultsA total of 20 studies involving 1 263 patients were included. The results of meta-analysis showed that: compared with the posterior approach group, the anterior approach group had higher postoperative JOA score (MD=0.98, 95%CI 0.52 to 1.44, P<0.000 1), higher improvement (MD=12.18, 95% CI 6.65 to 17.71, P<0.000 1), higher re-operation rate (OR=3.21, 95%CI 1.70 to 6.08, P=0.000 3), longer operation time (MD=53.43, 95%CI 12.77 to 94.09, P=0.01) and more bleeding (MD=122.88, 95%CI 39.56 to 206.20, P=0.004), respectively. There was no significant difference in the incidence of complications between two groups (OR=1.49, 95%CI 0.88 to 2.51, P=0.14).ConclusionThe anterior approach for the treatment in OPLL of the cervical spine can achieve better postoperative neurological improvement and lower neurological deterioration, while the posterior approach for the treatment in OPLL has lower re-operation rate, less blood loss and shorter operation time. The incidence of complications between two groups is similar. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify above conclusion.