Patent ID: 8080038
Filing Date: 2011-12-20
Classification: A61B

Abstract:
1. A dynamic stabilization device configured for implantation into a spine, comprising: an outer coil spring formed from a first coil of a first wire and having a first working length, the first working length comprising the length of the first wire in a portion of the first coil that is able to bend or compress; and an inner coil spring formed from a second coil of a second wire and disposed within the outer coil spring, the inner coil having a second working length comprising the length of the second wire in a portion of the second coil that is able to bend or compress; wherein the outer spring first working length is substantially equal to the second working length of the inner coil spring; wherein the outer coil spring has a first diameter and a first number of turns; wherein the inner coil spring has a second diameter and a second number of turns; wherein the first diameter is greater than the second diameter; wherein the second number of turns is greater than the first number of turns; wherein the first working length is approximately equal to the first diameter multiplied by the first number of turns; and wherein the second working length is approximately equal to the second diameter multiplied by the second number of turns.