[Imaging of the fused spine]

Imaging interpretation of the fused spine requires adequate knowledge of instrumentation and fusion techniques. Familiarity with the normal imaging features is needed in order to detect complications. While such complications are relatively rare, their presence is clinically significant and may lead to repeat surgery. Mechanical complications related to instrumentation and fusion (improper device placement, pseudarthrosis, progression of disease at the adjacent non-fused segments) are distinguished from non-mechanical complications (infection, postoperative hematoma, pseudo-meningocele) that usually occur sooner. The different complications will be illustrated with focus on the optimal imaging work-up (radiographs, CT, MRI).