The lumbar area of the spine, composed of the vertebrae from T11 to S3, often becomes damaged over time. Lumbar spinal fusion aims to reduce back pain by stabilizing the damaged area of the spine. Pain comes from inflammation in damaged discs or joints or from pinched nerves. Fusing two or more vertebrae together using bone grafts and hardware such as plates or screws prevents movement and reduces nerve pressure and inflammation. Like any surgery, lumbar spinal fusion can have significant risks.
Persistent Pain
Pain can persist even after lumbar spinal fusion surgery; patients achieve satisfactory pain relief compared to preoperative pain 50 to 80 percent of the time, the Columbus Regional Health System's Hughston Spine Center states. Fusing more than two joints is less likely to result in pain relief because it places too much stress on nearby joints, orthopedic surgeon Peter Ullrich of the Neuro-Spine Center of Wisconsin reports.
Pseudoarthrosis
Pseudoarthrosis, a non-union of the fused bone, occurs in less than 20 percent of spinal fusions overall. Smokers have the highest rate of pseudoarthrosis because smoking interferes with new bone growth. Pseudoarthrosis occurs in 40 percent of smokers and around 8 percent of nonsmokers, reports Larry Davidson, M.D. of Memphis, Tennessee.
Graft/Hardware Complications
Problems can arise in the bone grafts or the hardware that hold them in place while the bone fuses. Portions of the graft may dissolve, leaving too little bone to fuse and requiring a second surgery to place more graft material and new hardware to hold them in place, eOrthopod states. Hardware can loosen, irritating tissues, or break off altogether, causing pain in other areas and possibly requiring further surgery.
Infection
Infection in the spine after lumbar fusion surgery can cause serious problems. Infection occurs in 1 to 5 percent of patients after surgery, most often in cases where metal hardware is used. Diabetes and excess weight also increase the risk of infection.
Muscle/Nerve Damage
Nerves to muscles are often cut during surgery, and blood supply can also be disrupted. Nerve damage and lack of blood supply can cause muscle weakness and fatigue. Nerve damage can also decrease sensation in the damaged areas, eOrthopod reports.
