Surgeons have struggled for years to find a way to prevent complications after long spinal fusions to the sacrum for adult scoliosis. Years ago, long rods were placed on either side of the vertebrae. But there was a high rate of pseudoarthrosis (false joint or movement at the joint). Problems from the resulting flat back were also reported.
Over time, this surgery has changed but the problems haven’t gone away. For awhile, it looked like the procedure was more successful than it really was. That’s because the results were only reported for a couple years after the operation. But the real problems started later than that.
In this study, 50 adults who had a long spinal fusion for scoliosis were followed for at least five years. The fusion was from the sacrum up to T10 or higher. Most of the time, lumbar pedicle screws were used in the lumbar and sacral areas.
Instead of one long rod connecting the entire spine together, smaller segments were secured using special hardware called instrumentation. Special surgical hooks were placed in the thoracic spine. Stainless steel or titanium implants were preferred.
More than half the group had both an anterior (from the front) and posterior (from the back) fusion. The lumbar spine was fused to the sacrum. Some patients had only a posterior fusion. No artificial bone substitute was used in the fusion (only donor bone). In posterior fusions, bone taken from the patient (autograft) was mixed with bone from a bone bank (allograft).
Complications and problems were reported. These included pseudoarthrosis, nerve root injury with paralysis, wound infection, and urinary tract infection. More minor problems such as dural tears (lining of the spinal cord), blood clots, or minor heart events were reported as well.
Despite all efforts to prevent it, there was still a high rate of complications. No one died or suffered a spinal cord injury. But one-fourth of the group developed pseudoarthroses. Most of these didn’t occur until two years or more after the fusion operation.
The authors suggest structural support should be used with anterior fusions for adults with scoliosis. All lumbar levels should be fused anteriorly. Fusing the sacrum to the ilium (pelvic bone) is needed to secure a stable base. Some of the hardware may have to be removed later.