PROXIMAL KYPHOSIS, “TOPPING OFF SYNDROME”, AND RETROLISTHESIS SECONDARY TO MULTILEVEL LUMBAR FUSION IN THE ELDERLY PATIENTS

Fifty-two patients older than sixty years had undergone multilevel lumbar decompression and fusion with instrumentation and reached a minimum two-year follow up. The relationship between abnormal sagittal plane configuration of the proximal segments and the number of lumbar fusion segments was radiographically analyzed. Group A (L1-L5 or S1) patients had two (20%) proximal vertebral compression fractures and four (40%) focal kyphosis. Group B (L2-L5 or S1) patients had one (6%) proximal vertebral compression fractures, five (33%) retrolisthesis and two (13%) focal kyphosis. Group C (L3-S1) had seven (39%) retrolisthesis. Group D had only one retrolisthesis and two disc height loss. Radiographically analyze the relationship between abnormal sagittal plane configuration of the proximal segments and the number of lumbar fusion segments in patients older than sixty years old. It appears that lumbar fusion up to L1 causes more kyphotic changes and topping off syndrome in the elderly. Fusion L2-L5 or S1 seems having less severe adjacent level degeneration. Retrolisthesis is a significant problem in fusion from L3-L5 or S1. The least adjacent level degenerative changes were seen in L4-S1 fusion. Selected limited instrumentation avoiding kyphotic segments or extending the fusion above the thoracolumbar junction may be the needed. Solid fusion was seen in 46 (88%) patients. There were ten patients in group A, and two (20%) had vertebral compression fractures in the most cranial vertebrae and four (40%) focal kyphosis. Of fifteen patients in group B, one (6%) had compression fracture, five (33%) retrolisthesis, and two (13%) focal kyphosis. Of eighteen patients in group C, retrolisthesis was seen in seven (39%) patients. Group D had nine patients with only one patient having retrolisthesis and two having disc height loss. Since January 1997, there were fifty-two consecutive patients with an average age of seventy years who have undergone multilevel lumbar decompression and posterolateral fusion with pedicle screw-rod instrumentation, and have reached a minimum two-year follow up. Postoperative radiographs of lumbar fusion were classified into group A (L1-L5 or S1), group B (L2-L5 or S1), group C (L3-L5 or S1) and group D (L4-S1).