CORR Insights^®: Apical and Intermediate Anchors Without Fusion Improve Cobb Angle and Thoracic Kyphosis in Early-onset Scoliosis

Excerpt

Early-onset scoliosis is a challenging problem that can result in severe deformity, pulmonary insufficiency, and early death. In recent years, there has been great interest in improving the lives of the children affected. Journals are stocked with studies describing competing options that often have similar or identical indications. Derotational casting or bracing, single or dual growing rods, the VEPTR (Synthes Spine Co. West Chester, PA, USA), Shilla (Medtronic Spine, Memphis, TN, USA), and anterior flexible tethers are some of the more widely-used options available. Casting and bracing certainly present the least chance of harm to the child and should be chosen for all but the most difficult-to-control curves. Although there is great interest in casting as a cure for infantile scoliosis, casting has also recently been demonstrated as a viable alternative to surgical procedures in delaying definitive fusion in young children [5]. Though occasional skin ulcers arise, growth occurs while spine flexibility is maintained. Growing rods and the VEPTR require regular open procedures to keep pace with the growth of the child. This leads to multiple opportunities for deep infection. Because the devices are distraction-based, kyphosis is often an issue. The diminishing height gains seen with multiple lengthenings [8] or spontaneous spinal fusions [2] also are disturbing. Magec Rods (Ellipse Technologies, Irvine, CA, USA) offer the hope of fewer operations as the rods can be lengthened without an operative intervention. However, these rods only elongate 45 mm, so revisions to place new rods can be expected. Of course, revisions for anchor shifting and similar issues also remain. At present, the high cost of the Magec rods will likely guarantee a financial loss for any hospital. In the Shilla technique, three to four apical vertebrae are exposed and fused using pedicle screws, while proximal and distal screws that capture, but do not lock to the rod, are placed without subperiosteal exposure. Rods with sufficient length are inserted allowing for growth, which occurs as the end anchors slide over the rods without the need for additional procedures. Early published results [7] seem promising, but concerns about early spontaneous fusions and the challenges of placing secure pedicle screws in a young child have limited the procedure’s acceptance. A similar growth strategy, the Luque trolley, has been largely abandoned because of early spontaneous fusions complicating growth [6]. …