Common risks associated with lower back fusion surgery include infection, blood clot formation, neural damage, graft rejection and soreness at the graft site. Failure of the fusion and fracturing of the embedded pieces of metal may also occur following the operation, notes WebMD.
Surgeons perform lumbar spinal fusions by using bone grafts and metal implants. The potential risks vary and are influenced by the patient's age, health status, the reason for surgery and the type of surgical technique used, states WebMD.
Patients may experience bleeding following a spinal fusion, although this is usually not a cause for concern, according to American Academy of Orthopaedic Surgeons. Pseudarthrosis, which is characterized by inadequate bone growth, may also develop in patients who smoke. A follow-up surgery may be required to correct this issue.