Distraction-based growth friendly implants with rib anchors

Abstract

In this chapter, we will describe the indications, surgical technique, and potential benefits of distraction-based growth-friendly implants with rib anchors (hybrid growing rods) in the management of early-onset scoliosis. This technique is described both for use in the management of early-onset scoliosis involving the thoracic spine and for deformities of the cervicothoracic region. The use of ribs for growing rod anchors has the benefit of avoiding dissection and intentional fusion of the upper thoracic spine, which is important for pulmonary development. Additionally, as ribs are mobile, a theoretical benefit of rib anchors is motion preservation, as opposed to spontaneous autofusion observed frequently after extended treatment with rigid standard growing rod constructs. Hooks from standard spinal instrumentation systems are used as rib anchors in this technique. Benefits of using standard spinal hooks over specialized rib implants include that no special equipment, training, or institutional approval is needed, and multiple ribs at a time may be used for load sharing. In most cases, a thoracotomy, elevation of the scapula, or cutting of tissue between ribs is not indicated. Distraction of the concavity of scoliosis leads to expansion of the hemithorax and harmonious separation between ribs. Neuromonitoring of the upper extremities is indicated when distracting on rib anchors and positioning the arms in adduction is recommended if there is particular concern for brachial plexus injury.