The incidence of heterotopic ossification in cervical artificial disc replacement in Chinese mainland population: A meta-analysis

Abstract

Objective To investigate the incidence of heterotopic ossification in cervical artificial disc replacement in Chinese mainland population by meta-analysis.Methods The related literatures published between 1997 and June 2012 were collected from both English databases,including Pubmed,Ovid,Cochrane library and Embase,and Chinese databases including Chinese Biomedical Literature Database,China National Knowledge Infrastructure,VIP database and Wanfang database.Literatures were selected in strict accordance with the inclusion and exclusion criteria.Studies providing data of prevalence of heterotopic ossification after cervical artificial disc replacement in Chinese mainland population were included.The information of literatures was extracted by excerpts questionnaire,and recorded by two independent researchers.I2 was calculated to test heterogeneity among studies.A random effects model was used if I2 ≥25％.Subgroup analysis was done according to the number of levels of disc replacement,brands of implants and duration of follow-up.Sensitivity analysis was done according to the sample size.The Meta-Analyst software was used for statistical analysis.Results A total of forty studies (1822 cases) were included in this study.The pooled incidence of heterotopic ossification was 7.3％ (95％CI:4.7％ to 11.0％).For single and mixed level disc replacement,the incidence was 11.6％ and 5.8％,respectively.For single and mixed level disc replacement using Bryan disc,the incidence was 13.8％ and 5.4％,respectively,and the total incidence was 7.2％.No matter the single or mixed level disc replacement,the incidence of heterotopic ossification increased with follow-up.Conclusion The incidence of heterotopic ossification in cervical artificial disc replacement is high in Chinese mainland population,while it is lower than in foreigners.However,it is necessary to monitor its long-term incidence due to its increase with follow-up. Key words: Cervical vertebrae; Prostheses and implants; Ossification, heterotopic; Meta-analysis