Luo J, et al. - authors performed this meta-analysis to evaluate the rate of adjacent segment disease (ASD) between cervical disc arthroplasty (CDA) and anterior cervical decompression and fusion (ACDF). As per pooled data, CDA group had significantly lower adjacent segment diseases than that in the ACDF group. Compared with the ACDF group, there were fewer adjacent segment reoperations in the CDA group. Findings thereby indicate the superiority of CDA to the ACDF in terms of ASD and adjacent segment reoperations. Thus for the treatment of cervical degenerative disc diseases, the HS was recognized as a superior alternative invention to preserve cervical range of motion and reduce the risk of ASD.