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 1-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.