Spinal Implant System and Method

A bone screw for fixation in a vertebral body of a spine, comprising:

• an elongated shank having bone engaging threads and defining a longitudinal axis;
• and
• a rod-engaging portion connected to one end of said elongated shank, said rod-engaging portion defining a vertical axis and a channel for receiving a spinal rod therein oriented perpendicular to said vertical axis,
• wherein said rod-engaging portion is connected directly to said elongated shank so that said longitudinal axis intersects said channel and is not colinear with said vertical axis.

A kit for forming a spinal construct for correcting a plurality of vertebral levels of a patient's spine, the kit comprising:

• a plurality of bone screws, each having;
• an elongated shank having bone engaging threads and defining a longitudinal axis;
• a rod-engaging portion defining a channel for receiving a spinal rod therein oriented perpendicular to said vertical axis;
• and
• an intermediate portion disposed between and directly connected to said rod-engaging portion and said elongated shank, said intermediate portion having a height along said longitudinal axis, wherein each of the plurality of bone screws has a different height ranging from 0.5 mm to 30 mm.

A kit for forming a spinal construct for correcting a plurality of vertebral levels of a patient's spine, comprising:

• an elongated spinal rod defining a fixed curved contour adapted for percutaneous introduction along a patient's spine, said fixed curved contour being non-perpendicular relative to an optimum insertion angle for a bone screw into vertebral bodies at different vertebral levels;
• and
• a plurality of bone screws having;
• an elongated shank with bone engaging threads and defining a longitudinal axis;
• and
• a rod-engaging portion defining a channel for receiving the spinal rod therein,
• wherein said elongated shank is attached to said rod-engaging portion at different non-perpendicular angles to align with the optimum insertion angle for a bone screw at each of the different vertebral levels.

A method for forming a spinal construct for correcting a plurality of vertebral levels of a patient's spine, comprising the steps of:

• determining the T10-S2 distance between the T10 vertebra and the S2 vertebra of the patient's spine;
• determining the L1-S2 distance between the L1 vertebra and the S2 vertebra of the patient's spine;
• providing a spinal rod having a total length at least equal to the T10-S2 distance, in which the spinal rod includes a caudal portion and a cranial portion, in which the length of the caudal portion is sixty percent (60%) of the total length and in which the caudal and cranial portions are oppositely curved at the same fixed radius to form a fixed curved contour of the rod, wherein the fixed radius is calculated using the following equation—((L1-S2 distance)2/8A)+A/2, where A is the anterior displacement of the caudal portion, measured from a line between one end of the rod and the cranial portion, that is 9-11% of the total length of the spinal rod;
• providing a plurality of bone screws, each having;
• an elongated shank having bone engaging threads and defining a longitudinal axis;
• a rod-engaging portion defining a channel for receiving a spinal rod therein oriented perpendicular to said vertical axis;
• and
• an intermediate portion disposed between and directly connected to said rod-engaging portion and said elongated shank, said intermediate portion having a height along said longitudinal axis, wherein each of the plurality of bone screws has a different height ranging from 0.5 mm to 30 mm in 0.5 mm increments;
• determining the distance between the caudal portion of the spinal rod and each of the instrumented L1-S1 vertebrae, and the distance between the cranial portion of the spinal rod and each of the instrumented T10-T12 of the patient's spine;
• selecting one of the plurality of bone screws for each of the instrumented vertebrae having a height corresponding to the distance between the spinal rod and the corresponding vertebra;
• implanting the selected bone screws into the corresponding vertebra;
• and
• attaching each of the selected bone screws to the spinal rod.