LAUSR

To the Editor: Total cervical disc replacement (TDR) has beenwidely used to treat cervical degenerative disc diseases (CDDD). However, implant-related complications, including implant migration, implant subsidence, heterotopic ossification (HO), and anterior bone loss (ABL), have been reported bymany studies. ABL has received more attention in recent years; however, this phenomenon has been recognized only in cervical artificial discs without keels, including Bryan, Baguera-C, Discocerv, and Mobi-C. Therefore, the first aim of this study was to evaluate the incidence of ABL in a keeled artificial disc, the Prestige-LP cervical disc system (Medtronic Sofamor Danek Inc., Memphis, TN, USA).