The most common cause of iatrogenic flatback syndrome is Harrington
distraction instrumentation extending into the lower lumbar spine.
Other common causes and exacerbating factors include failure to enhance
regional lordosis during lumbar fusion for degenerative spondylosis,
development of pseudarthrosis or postoperative loss of correction, development
of kyphosis at the thoracolumbar junction, development of degeneration and
decompensation cephalad or caudad to a prior fusion, and hip flexion
Prevention of flatback syndrome involves preoperative assessment of
sagittal balance, avoidance of distraction instrumentation and extension of
long fusions into the lower lumbar spine, enhancement of physiologic lordosis
during lumbar fusions, and intraoperative positioning with the hips
Treatment of flatback syndrome involves corrective pedicle subtraction or
Smith-Petersen osteotomies with segmental instrumentation.
Polysegmental osteotomies and vertebral column resection may be utilized in
cases of sloping global sagittal imbalance and related severe coronal
Following surgical treatment, sagittal balance is generally improved with
fair-to-good clinical outcomes, high patient satisfaction, and moderately high
perioperative complication rates.