Improvement of Kyphoscoliosis in a 9-Year-Old Using Growth Modulation With a Posterior Tether: A Case Report.

Abstract

Our aim was to report the first case of a posterior tether used for growth modulation in the treatment of spinal deformity. A 9-year-old boy with progressive kyphoscoliosis failed multiple attempts of brace treatment; the deformity progressed to kyphosis of 73° and scoliosis of 41° on standing radiographs. We placed a posterior tether using hydroxyapatite-coated pedicle screws with a flexible polymer cord under modest compression unilaterally from T3 to T11 with no subperiosteal dissection and no attempt at fusion. Immediately postoperatively, the kyphosis improved from 73° to 65° and the scoliosis from 41° to 26°. At 26 months postoperatively, the kyphosis improved to 42° and the scoliosis to 26°. At 31 months postoperatively, distal junctional kyphosis developed. The patient then underwent a spine fusion at age 11 years. We noted at surgery that the previously tethered spine from T3 to T11 was fused with no motion present even after implants were removed. A posterior unilateral tether was successful at progressively improving kyphosis and preventing worsening of scoliosis in a 9-year-old boy, but it led to fusion of the spine within 31 months.