Dynamic implants for spinal deformities: Development and clinical experience

Abstract

Scoliosis is a common problem and concern for children. This deformity of the spine develops in 2-3% of growing children. In 10% of those children, the deformity progresses and needs medical treatment. Often a brace can be used, but with severe cases surgery is required for correction and fusion. However, surgical treatment of scoliosis is extremely difficult in children that are still growing. An implant is needed that can accommodate the growth in the spine. However, current implants are static and cannot further correct the spine after implantation. After undergoing surgery with these static implants, multiple re-operations are needed in young children to control the scoliosis. Therefore, a dynamic implant was developed that can grow with the spine: The Spring Distraction System. By using a continuous distraction force in the implant, the spine can continue to grow while correcting the spine during implantation. This Spring Distraction System was used in a clinical trial and performed as expected, correcting the spine during implantation. To further develop the dynamic implant, a torsional force was added to correct the rotation in the scoliotic spine. This implant was investigated in an animal study and showed that a scoliotic spine could be corrected with the combination of these forces. This thesis presents exciting progress in treatment of scoliosis and can potentially lead to a cure for scoliosis in the future.