We are assuming by saying you had a long fusion that there were several spinal segments fused. Most of the time using this term means that fusion occurred within the lumbar spine and that the lumbar spine was fused with the sacrum.
Since you had a long fusion, it’s possible you had bone grafts (bone harvested for use in fusions), graft extenders (materials used to increase the amount of graft available), and instrumentation (metal rods, plates, and/or screws to hold the bones in place until fusion occurs).
With long spine fusions, there is always a risk of fusion failure. The instrumentation may loosen, shift, pullout, or break. Pseudoarthrosis (formation of a false joint with movement at the fusion site) can occur.
Mesh cages are used to fill in the space where the disc material is removed. The cages are filled with bone graft material to help local bone incorporation. But sometimes the cage gets in the way of seeing the fusion site.
If that’s the case, it may be possible to get a better view using a CT scan. But the scans are more expensive and expose the patient to more radiation, so they are not used routinely. You can discuss your concerns with the surgeon and see if a CT scan is advised.
In the future, this problem may be eliminated. There is a new type of cage called a PEEK cage. PEEK refers to polyetheretherketone. It’s a plastic substance with biomechanical properties similar to those of cortical bone. It doesn’t show up on plain X-rays. Small metallic markers are placed on the front and back of the device to help the physician monitor its position.