Partially overlapping limited anterior and posterior instrumentation for adult thoracolumbar and lumbar scoliosis: a description of novel spinal instrumentation, "the hybrid technique"

Abstract

Progressive and/or painful adult spinal deformity in the thoracolumbar and lumbar spine is sometimes treated surgically by long posterior fusions from the thoracic spine down to the pelvis, especially where there is a major thoracic curve component. Recent advances in anterior spinal instrumentation and spinal surgery technique have demonstrated the improved corrective ability offered by anterior stabilization systems, and the added benefit of limiting the number of vertebral fusion levels required for control of the deformity. The "hybrid technique" is a novel use of anterior instrumentation that applies limited anterior instrumentation down to the low lumbar spine (rods and screws), and partially overlapping short-segment posterior instrumentation to the sacrum (pedicle screws and rods). These constructs avoid posterior thoracic instrumentation and fusions, and avoid extension of posterior instrumentation to the pelvis. In the first 10 patients treated using this technique, thoracolumbar and lumbar major curve correction has averaged 71 and 82% in the immediate postoperative period (n = 7), respectively, and 59 and 68% at 2-year follow-up, respectively. The technique is an appealing and attractive alternative for treatment of thoracolumbar and lumbar scoliosis in the adult population, and avoids the requirement for applying spinal fixation to the thoracic spine and the pelvis.

Fig. 1

Intraoperative photographs of the anterior instrumentation technique. Perspective shows operative field through a left thoracolumbar approach as viewed by the surgeon, with top being the anterior of the patient and right being the head of the patient. Subpanel (A) shows the placement (upper) and seating (middle) of vertebral staples, and probing (lower) for vertebral body screws. Subpanel (B) shows prerotation/reduction position of the rod (upper), postrotation/reduction position of the rod and placement of interbody cages (middle) and axial compression (lower) to prevent kyphosis and agument deformity correction. Subpanel (C) shows intraoperative deformity correction achieved. Subpanel (D) shows the placement of the second (stabilizing) rod

Fig. 2

Single-rod hybrid instrumentation case summary. An otherwise healthy 50-year-old woman with previously untreated adolescent idiopathic scoliosis presented with complaints of low back pain and deformity. She underwent single-rod hybrid instrumentation spine surgery with left iliac crest bone graft for supplementation of the posterior fusion. Four years postoperatively, she had upright posture, physiological coronal and sagittal balance, and occasional back and leg symptoms controlled by NSAIDs. Subpanel (A) shows preoperative x-ray with 37° thoracic, 59° lumbar, and 40° lumbosacral fractional curves. Subpanel (B) shows postoperative x-ray with single-rod hybrid construct of 1/4 inch stainless steel, anterior spine fusion from T10–L5 and posterior spine fusion from T10–S1. Postoperative curves measured 23, 20, and 11° in the thoracic, lumbar, and lumbosacral fractional curves, respectively. Subpanel (C) shows preoperative clinical photograph illustrating coronal imbalance 2.5 cm to the left and obvious scoliosis deformity. Subpanel (D) shows postoperative clinical photograph illustrating physiological coronal balance and improvement of deformity

Fig. 3

Dual-rod hybrid instrumentation case summary. A 56-year-old woman with mitral valve prolapse and lumbar stenosis previously treated by L5–S1 laminectomy presented with complaints of low back pain and deformity which had caused her to leave her job. She underwent dual-rod hybrid instrumentation spine surgery with right iliac crest bone graft for supplementation of the posterior fusion. Three years postoperatively, her pain was gone and she was back to work. She had upright posture, physiological coronal and sagittal balance, occasional leg symptoms, and was very satisfied with her surgery. Subpanel (A) shows preoperative x-ray with 29° thoracic, 53° lumbar, and 28° lumbosacral fractional curves. Subpanel (B) shows postoperative x-ray with titanium dual-rod hybrid construct, anterior spine fusion from T11–S1, and posterior spine fusion from L4–S1. Postoperative curves measured 14, 13, and 12° in the thoracic, lumbar, and lumbosacral fractional curves, respectively. Subpanel (C) shows preoperative clinical photograph illustrating coronal imbalance 4.5 cm to the left and obvious scoliosis deformity. Subpanel (D) shows postoperative clinical photograph illustrating physiological coronal balance and improvement of deformity