Zhang Qiang, Chen Zhe, Lin Yazhou, Cao Peng, Zhang Xingkai, Wu Wenjian, Liang Yu
Department of Orthopedics, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China.
Orthop Res Rev. 2025 May 16;17:213-220. doi: 10.2147/ORR.S517491. eCollection 2025.
PURPOSE: The aim of this study was to explore short-term radiological findings after contiguous two-level ACDF with Zero-P VA devices. METHODS: Patients who underwent contiguous two-level anterior cervical discectomy and fusion (ACDF) from C3 to C7 with a Zero-P VA system were followed. Cervical anteroposterior and lateral X-rays and functional outcomes were assessed 3 months after surgery. RESULTS: Overall, 34.9% of patients had prosthesis subsidence and 74.6% screw loosening. Up to 46.8% of the patients with screw loosening also experienced prosthesis subsidence compared with 0 patients without screw loosening (=0.0005). The screw-loosening rate was 91.7% in patients with poor positioning of the screw/cage and 70.6% in patients without poor positioning of the screw/cage, but no statistical difference was found between the groups (=0.267). The subsidence rate was 50% in patients with poor positioning of the screw/cage and 31.4% in patients without poor positioning of the screw/cage, but no statistical difference was found between the groups (=0.314). VAS scores of patients with prosthesis subsidence were much higher than those without (=0.031), but this difference was not found for patients with or without screw loosening (=0.116). The NDI scale was much higher in patients regradless of screw loosening or subsidence. CONCLUSION: Screw loosening and prosthesis subsidence happen frequently after contiguous two-level ACDF with Zero-P VA. Screw loosening seems to be the only risk factor for prosthesis subsidence.
Bratisl Lek Listy. 2019