AP X-ray of previous lumbosacral instrumented fusions
Lateral X-ray of previous instrumented lumbosacral fusions
Image guided diagnostic injection verified diagnosis
The patient noted significant pain relief after his SI joint fusions; however, he had persisting symptoms consistent with flat back syndrome, also known as positive sagittal imbalance (Figs. 13.4, 13.5, and 13.6).
Postoperative AP X-ray showing bilateral SIJ instrumentation
PA scoliosis film
Lateral scoliosis film showing “flat back” syndrome
The patient then underwent spinal reconstruction with a lumbar pedicle subtraction osteotomy. Distal fixation was challenging with the SI joint implants in place. The patient is quite satisfied with his clinical improvement (Figs. 13.7, 13.8, 13.9, and 13.10).
Postoperative lateral scoliosis film after subtraction osteotomy
Postoperative PA scoliosis film after subtraction osteotomy
AP X-ray after subtraction osteotomy
Lateral X-ray after subtraction osteotomy
It is now recognized that adjacent segment degenerative disease does affect the SIJ when a long lumbosacral fusion is performed. If the SIJ is fixated when performing a long lumbosacral fusion, certain pitfalls such as over abundant iliac bone graft harvesting, with its associated potential effects on the SIJ and the ramifications of positive sagittal balance, especially in the elderly, must be considered by the spine surgeon proactively to avoid potential long-term complications. When both positive sagittal balance and the SIJs are symptomatic and require surgery, the spine surgeon must be cognizant of the best methods to use and in what sequence to use them in order to achieve the best overall result for the patient.