Patent ID: 9060810
Filing Date: 2015-06-23
Classification: A61B

Abstract:
1. A growing rod system for correcting a curvature or rotational orthopedic deformity of a curved spine of a body, comprising: at least one growing rod assembly including a first longitudinal rod segment, a second longitudinal rod segment, and a fluid actuator that is operable to extend the first and second rod segments longitudinally relative to each other in opposite directions from a retracted position to an extended position, wherein the growing rod assembly is adapted to be mounted within the body and spanning the orthopedic deformity, wherein the fluid actuator is a piston-cylinder actuator including a cylinder with an internal bore and a piston with a bore-received portion that telescopically reciprocates within the cylinder bore, wherein the first rod segment extends longitudinally from one of the piston or the cylinder and the second rod segment extends longitudinally from the other of the piston or the cylinder, wherein the bore-received piston portion and the cylinder bore of the piston-cylinder actuator are sagittally curved with a same, constant radius of curvature selected to generally conform to a desired post-treatment curvature of the spine, wherein the radius of curvature of the piston and the cylinder is maintained constant as the rod segments telescopically reciprocate with respect to each other from the retracted position to the extended position to move portions of the spine relative to each other to form the desired post-treatment curvature of the spine, wherein the piston-cylinder actuator includes an anti-rotation mechanism having mating keyed elements of the piston and the cylinder to prevent the piston and the cylinder from rotating relative to each other while permitting longitudinal extension relative to each other, wherein the piston-cylinder actuator includes an anti-retraction mechanism includes mating catch elements on the piston and the cylinder to prevent the piston and the cylinder from longitudinally retracting relative to each other while permitting longitudinal extension relative to each other, wherein the curved piston and the curved cylinder are formed by a first precision manufacturing technique selected from the group consisting of direct meal laser sintering, centrifugal pressure investment-casting, vacuum pressure investment-casting, and powder casting, and wherein the curved piston and the curved cylinder have curved surfaces that mate with each other and are smoothened by a second precision manufacturing technique selected from the group consisting of flexible honing, electropolishing, electroplating, wherein the curved piston and the curved cylinder are thereby formed with the mating curved surfaces sufficiently mating that they minimize binding and fluid leaking; and at least one fluid delivery assembly including at least one fluid line that is connected to the piston-cylinder actuator to deliver an actuating fluid to the piston-cylinder actuator to drive the piston-cylinder actuator to extend the rod segments.