Spinal implant system and a method for installing the implant onto a vertebral column

A spinal implant for stabilizing a vertebrae of a vertebral column, wherein the vertebral column has a curvature along at least one vertical axis and each vertebra has a pair of pedicles, comprising:

• at least two cylindrical clamps each having a first flange, and a second flange separated from said first flange by a slit, said clamps further having a first bore that extends through said first and second flanges, said first and second flanges both having cylindrical outer surfaces and a second bore essentially perpendicular to said first bore;
• a rod adapted to be inserted into and extend through said second bores;
• at least two screws, each said screw having a first threaded portion adapted to be attached to the pedicle of a vertebra and a second threaded portion adapted to extend through said first bore, each said screw further having a hexagonally shaped shoulder between said first and second threaded portions, said second threaded portion having a predetermined outer diameter and said first bore having a predetermined inner diameter larger than said outer diameter of said screw enabling said clamp to rotate up to 30.degree. about an axis perpendicular to the longitudinal axis of said screw and shoulders being adapted to engage said cylindrical outer surface of second flanges of said clamps;
• and
• at least two nuts adapted to be threaded onto said second portion of said screws, each screw having one nut with an annular flange adapted to engage said cylindrical outer surface of said first flange of said clamp such that said annular flange deflects to lock said first nut onto said clamp wherein said cylindrical clamps can be rotated about an axis perpendicular to a longitudinal axis of said screw without interference between said cylindrical clamp and said shoulders and said nuts.

A spinal implant for stabilizing the vertebrae of a vertebral column, wherein the vertebral column has a curvature along at least one vertical axis and each vertebra has a first and second pedicle, comprising:

• at least two cylindrical clamps, each said clamp having a first flange and a second flange separated from said first flange, by a slit, said clamps further having a first bore that extends through said first and second flanges, said first and second flanges both having cylindrical outer surfaces and a second bore essentially perpendicular to said first bore;
• a rod that extends through said second bores, said rod having a radius approximating the curvature of the vertebral column;
• at least two screws, each said screw having a first threaded portion attached to the first pedicle of a vertebra and a second threaded portion that extends through said first bore such that each said screw has a clamp attached thereto, each said screw further having a shoulder that engages said cylindrical outer surface of said second flange of said clamp;
• at least two nuts attached to said second portion of said screws, each screw having one nut engaging said cylindrical outer surface of said first flange of said clamp such that said first flange is deflected, said cylindrical clamps can be rotated about an axis perpendicular to a longitudinal axis of said screws without interference between said cylindrical clamps and said shoulders and said nuts.
• whereby said nut and said shoulder deflect said first and second flanges so that said clamp is pressed onto said rod such that said rod is held in firm engagement by said clamp.

A method for attaching a spinal implant to a vertebrae of a vertebral column to stabilize the vertebrae, wherein the vertebral column has a curvature along at least one vertical axis and each vertebra has a first and second pedicle, comprising the steps of:

• providing;
• at least two cylindrical clamps each having a first flange, and a second flange separated from said first flange by a slit, said clamps further having a first bore that extends through said first and second flanges, said first and second flanges both having cylindrical outer surfaces and a second bore essentially perpendicular to said first bore;
• a rod adapted to be inserted into and extend through said second bores;
• at least two screws, each said screw having a first threaded portion adapted to be attached to the pedicle of a vertebra and a second threaded portion adapted to extend through said first bore, each said screw further having a shoulder between said first and second threaded portions adapted to engage said cylindrical outer surface of said second flange of said clamp;
• at least two nuts adapted to thread onto said second threaded portion of said screws, each screw having one nut adapted to engage said cylindrical outer surface of said first flange of said clamp;
• attaching said screws to the first pedicle of at least two vertebra such that each vertebra has one screw;
• inserting said rod into said second bores of said clamps;
• placing said clamps and said rod onto said screws such that said second portion of said screws is inserted through said first bores of said clamps, said cylindrical clamps being capable of rotation about a longitudinal axis of said screws without interference between said cylindrical clamps and said shoulder and said nuts;
• screwing said nuts onto said second threaded portion of said screws, such that each screw has one nut, each said nut being screwed onto said second threaded portion until said nut engages said first flange of said clamp and said second flange of said clamp engages said shoulder;
• and
• tightening said nut of each screw such that said first and second flanges are deflected, pressing said clamp onto said rod, whereby said rod is securely fastened to the vertebrae to hold the vertebrae in place.