Subsidence of Titanium Mesh Cage A Study Based on 300 Cases

Study Design: A cohort study. Objective: To clarify the risk factors for the subsidence of the titanium mesh cage (TMC) after anterior cervical corpectomy and fusion. and to discuss their clinical correlations. Summary of Background Data: Fusion with TMC after anterior cervical corpectomy has become popular as an established treatment for cervical degenerative diseases, but postoperative TMC subsidence has often been reported in the literature. Methods: A total of 300 patients with anterior cervical corpectomy and TMC fusion were included in the study, including 1-level corpectomy in 236 patients and 2-level corpectomy in 64. TMC Subsidence, radiologic findings, and clinical results were evaluated in the 12-month follow-up period. Results: TMC subsidence occurred in 239 (79.7%) cases , including mild Subsidence (1 to 3 mm) in 182 (60.7%) and severe subsidence ( > 3 mm) in 57 (19.0%). Two-level corpectomy was more susceptible to severe subsidence, when compared with I-level corpectomy (P < 0.001). Japanese Orthopedic Association recovery rate for severe subsidence was significantly lower than that for no subsidence (P = 0.010). Severe subsidence was correlated with subsidence-related complications, including neck pain, neurologic deterioration, and instrument failure. Conclusions: TMC subsidence was a common phenomenon after anterior cervical corpectomy and fusion with TMC. Level of corpectomy was a unique risk factor for severe subsidence in this study, which might have led to bad clinical results and subsidence-related complications.