Patent ID: 8043337

Claim:
An implant comprising: a first bone anchor including, a first head and a first tip, and a first engaging surface adapted to engage a first lateral surface of a vertebra, the first engaging surface being continuously curved with a first radius of curvature along a first longitudinal axis between the first head and the first tip and being continuously curved with a second radius of curvature larger than the first radius of curvature perpendicular to said first longitudinal axis; a second bone anchor including, a second head and a second tip, and a second engaging surface adapted to engage a second lateral surface of the same vertebra opposite the first lateral surface, the second engaging surface being continuously curved with said first radius of curvature along a second longitudinal axis between the second head and the second tip and being continuously curved with said second radius of curvature perpendicular to said second longitudinal axis; a flexible horizontal rod connected to the first head of the first bone anchor and the second head of the second bone anchor; wherein the first head of the first bone anchor and the second head of the second bone anchor are spaced apart along the flexible horizontal rod by an adjustable distance; wherein the adjustable distance can be reduced in order to cause the first engaging surface of the first bone anchor to engage the first lateral surface of a vertebra and cause the second engaging surface of the second bone anchor to engage the second lateral surface of the same vertebra and thereby secure the flexible horizontal rod to the vertebra; and a third bone anchor adapted to be attached to a first portion of another vertebra; a fourth bone anchor adapted to be attached to a second portion of the same another vertebra; another flexible horizontal rod connected to the third bone anchor and the fourth bone anchor; and a rigid vertical rod; the rigid vertical rod connected between the flexible horizontal rod and the another flexible horizontal rod; wherein the rigid vertical rod is connected to the flexible horizontal rod at a position about halfway between the first bone anchor and the second bone anchor and spaced from the first bone anchor and the second bone anchor; and wherein the rigid vertical rod is connected to the another flexible horizontal rod at a position about halfway between the third bone anchor and the second bone anchor and spaced from the third bone anchor and the fourth bone anchor.