cage subsidence
Migration or sinking of an interbody implant into the adjacent vertebral endplates, compromising fusion and alignment.
Full Definition
Cage subsidence is a significant postoperative complication where an interbody fusion cage migrates or sinks into one or both adjacent vertebral endplates. This can occur due to inadequate endplate preparation, poor bone quality, oversized implants, or excessive loading before fusion consolidation. Subsidence can result in loss of disc height, foraminal narrowing, sagittal malalignment, and potential nonunion. Recognition of cage subsidence on follow-up imaging is crucial as it may require revision surgery to restore proper alignment and achieve solid fusion.
Usage
Usage note: Quantify the degree of subsidence in millimeters when documenting on imaging.
In Context
- "Postoperative CT showed 3mm of cage subsidence at the L5-S1 level." — follow-up imaging report
- "Revision surgery was indicated due to symptomatic cage subsidence causing foraminal stenosis." — surgical consultation