Curved spine of a patient with scoliosis Approximately seven million Americans live with scoliosis, a condition wherein the spine is curved side-to-side in an s- or c-shape. Individuals living with this condition may be restrained in their physical abilities by shortness of breath, chest and back pains, and limited spinal movement. While more mild cases of scoliosis may be addressed through posturing techniques, braces, and occupational therapy, more severe angles of curvature require surgery.

Surgery is often recommended for patients with a high likelihood of progression, cosmetically unacceptable curvature, or curves that result in physical interference, such as with sitting or breathing. The procedure often entails spinal fusion with instrumentation, wherein various types of anchors are connected to the spinal vertebrae in a rod-based system. The rigidity imparted by these rods, however, reduce spinal column mobility, thereby potentially limiting the patient’s movement just as much as the scoliosis itself did. This rigidity may also permit the creation of arthrodesis, which is spinal fusion between vertebrae. These methods also pose the inconvenience of definitively immobilizing the spinal column, thereby limiting any further growth of the affected portions, a particular problem in children affected with this condition. Further still, the markedly elevated forces concentrated at the ends of these rod structures can lead to accelerated degeneration and failure of spinal elements like discs and ligaments.

A spine corrected with the traditional, fixed method to correct scoliosis The deformity corrections these surgical methods principally address are limited to the sagittal and front planes, while only minimally (if at all) addressing vertebral rotation. This is an important limitation because a vertebra with axial rotation as seen in scoliosis has a marked deviation of posterior elements into the concavity of the curvature, which these methods fail to address. This oversight can lead to marked residual deformity and rib cage asymmetry. Furthermore, the invasive nature of these operations, wherein the surgeon must place these rigid instrumentations, poses significant health risks.

In view of all of these shortcomings in the field of spinal fixation surgery, there was a great need for a fusionless treatment for spinal deformities that is relatively simple and easy to implement. Warsaw Orthopedic, in Indiana, met such a need with its patent entitled, “Device for dynamic spinal fixation for correction of spinal deformities.” This new invention has the ability to de-rotate improperly rotated and improperly aligned vertebral bodies without having to permanently fix the vertebral bodies in place. The invention also provides a treatment for spinal deformities in skeletally immature individuals (i.e., children) that allows for natural growth of the spine to correct the deformity.

The patent discloses embodiments that, through a non-linear placement of vertebral anchor means and/or flexible interconnection, together with use of flexible interconnection, permit correction of the spinal deformity either during operative intervention or in a progressive manner. The correction occurs through a minimally invasive surgical approach, which is a welcome improvement over the invasive spinal fusions previously known in the art.

The system for treatment comprises at least three vertebral anchor means for anchoring into three different vertebral bodies, which may be positioned in a non-linear manner. The flexible interconnection means attached to these vertebral bodies allows for curvature correction without limiting the patient’s spinal mobility in the way that a rigid cable would.