Objective Cervical disc herniation(CDH)is one of the common orthopaedic diseases.With the in-depth study of it and the development of cervical implants,the establishment of cervical fusion animal models has become an indispensable part.Notably however,studies of the establishment and evaluation of cervical fusion animal models in China are currently lacking.This study aimed to provide a suitable animal model and evaluation scheme for implants for cervical spine-related research.Methods Small-tailed Han sheep were chosen for anterior cervical discectomy fusion(ACDF)after modified surgery,and a polyetheretherketone(PEEK)interbody fusion cage(Cage)(control group),3D-printed Ti6Al4V Cage(group 1),and new method Ti6Al4V Cage(group 2)were implanted in different cervical segments(C2/3～C4/5)in each sheep,respectively.Hematology and histopathological analyses were carried out after surgery to evaluate recovery of sheep and the biosafety of the materials.Bone in-growth and bone fusion were assessed by X-ray,computed tomography(CT),Micro-CT and quantitative analysis,hard tissue section staining,and biomechanical tests.Results The modified ACDF ovine model was established successfully.There were no significant differences in important hematology indexes(P＞0.05)and histopathological analysis showed no pathological changes,such as inflammatory cell infiltration.The implants had good biosafety.Furthermore,X-ray and CT examinations showed that the position of internal fixation and the interbody fusion were good.Micro-CT and quantitative analysis at 3 and 6 months after operation showed that compared with PEEK Cage group,the bone volume/total volume and trabecular number were significantly increased(P＜0.01)while the trabecular spacing was significantly decreased in the new method Ti6Al4V and 3D-printed Ti6Al4V groups compared with the PEEK Cage group(P＜0.01).Moreover,the new method new method Ti6Al4V Cage group had more bone growth(P＜0.01).Hard tissue section staining demonstrated that the pores of the new method Ti6Al4V Cage and 3D-printed Ti6Al4V Cage had obvious bone growth and relatively dense pores in the new method Ti6Al4V and 3D-printed Ti6Al4V groups,and the combination was slightly better than that of PEEK Cage.Biomechanical evaluation indicated that the new method Ti6Al4V Cage and 3D-printed Ti6Al4V Cage reduced the range of cervical flexion-extension,lateral bending,and axial rotation(P＜0.05)compared with the PEEK cage,as well as enhancing the stability of the cervical vertebra,and the new method Ti6Al4 V Cage was more advantageous(P＜0.05).Conclusions After the establishment of the modified ACDF ovine model,reasonable and effective assessment method were used to demonstrate the suitability and effectiveness of the model and the good biosecurity of all three Cage materials.Compared with the PEEK Cage,the new method Ti6Al4V Cage and 3D-printed Ti6Al4V Cages showed better performances in terms of bone growth and bone fusion,which could enhance the stability of the cervical vertebrae.The new method Ti6Al4V Cage was particularly advantageous.