Anatomy-related risk factors for the subsidence of titanium mesh cage in cervical reconstruction after one-level corpectomy.

To clarify anatomy-related risk factors in the cervical spine with subsidence of titanium mesh cage (TMC) after one-level cervical corpectomy and fusion, we have assessed the radiological examinations and clinical outcomes for 236 patients. All the patients were underwent one-level corpectomy and TMC fusion between August 2003 and March 2006. The effects of the cervical posture, segmental curvature and endplate gradient on the postoperative phenomenon for these patients were evaluated. Our results suggested that in the patients who were followed up for 12 months, TMC subsidence occurred in 54 (28.6%) cases. C6 corpectomy had a significant higher risk (26/60, 43.3%) for TMC subsidence, which was correlated with the variation of the gradient of the vertebral endplates against cervical levels. Although the clinical outcome was comparable with those in the literature, the patients may have subsidence-related problems such as neck-shoulder pain, neurological deterioration and instrumental failure. In conclusion, to reduce the incidence of subsidence, TMC design should be optimized to be in line with anatomic characteristics of the cervical spine.