Anchor device for bone implantation during surgical procedures

1 . An anchor device for insertion into a bone, comprising

a single post suitable for implantation into a bone, and

a cord housing coupled to the post, comprising

a lower housing monolithic with the single post, the lower housing comprising at least a pair of cradles, each of the cradles for receiving therein at least one cord; and

an upper housing, separate from the lower housing, comprising at least a pair of clamps, each of the clamps for placement over the cords inserted into the cradles;

wherein the joining of the upper housing to the lower housing forms a pair of cord channels by the cradles and the clamps, to encase in each cord channel the cord received by each of the cradles; and

means for fastening the upper housing to the lower housing, causing the upper housing to press against and compress the cords within the cord channels to keep the cords clamped in and held snugly in place;

wherein

the lower housing further comprises a lower housing major surface located between the cradles; and

the upper housing further comprises an upper housing major surface located between the clamps;

wherein the upper housing major surface substantially abuts the lower housing major surface when the upper housing is joined to the lower housing and provides a stop to prevent overtightening of the upper housing to the lower housing.

2 . The anchor device of claim 1 wherein the lower housing major surface is flat and the upper housing major surface is flat.

3 . The anchor device of claim 1 wherein

the lower housing further comprises at least a pair of lower housing minor surfaces; and

the upper housing further comprises at least a pair of upper housing minor surfaces;

wherein the upper housing minor surfaces substantially abut the lower housing minor surfaces when the upper housing is joined to the lower housing and provide a stop to prevent overtightening of the upper housing to the lower housing.

4 . The anchor device of claim 3 wherein the lower housing minor surfaces are flat and the upper housing minor surfaces are flat.

5 . The anchor device of claim 3 wherein the adjoining of the upper housing major surface to the lower housing major surface and the upper housing minor surfaces to the lower housing minor surfaces provides a limit to the compression of the cords.

6 . The anchor device of claim 1 wherein the cord channels are formed by adjoining the upper housing major surface to the lower housing major surface, the upper housing minor surfaces to the lower housing minor surfaces, and the clamps to the cradles.

7 . The anchor device of claim 1 wherein

each of the cradles comprise a first end portion where the cord enters the cord channel, a middle portion, and a second end portion where the cord exits the cord channel, wherein the first end portion and the second end portion of each cradle each comprise an outwardly flared surface along an axis defined by the cord encased within and running along the cord channel; and

each of the clamps comprise a first end portion where the cord enters the cord channel, a middle portion, and a second end portion where the cord exits the cord channel, wherein the first end portion and the second end portion of each clamp each comprise an outwardly flared surface along an axis defined by the cord encased within and running along the cord channel;

whereby the outwardly flared surfaces enable the cord to bend and flex where the cord enters and exits the channel without fraying.

8 . The anchor device of claim 7 wherein each cradle comprises a non-smooth surface suitable for gripping the at least one cord when inserted therewithin,

wherein the non-smooth surface of each cradle comprises a plurality of ribs extending substantially perpendicular to the direction in which the cord is placed within each cradle,

wherein each clamp comprises a non-smooth surface suitable for gripping the at least one cord when inserted therewithin, wherein the non-smooth surface of each clamp comprises a plurality of ribs extending substantially perpendicular to the direction in which the cord is placed within the cradle;

whereby a locally compressive force is imparted on each cord so that each cord is held securely in place when the upper housing is joined to the lower housing around the cords and the cords are prevented from being pulled in either direction in the event there are stresses on the cords imparted during normal use.

9 . The anchor device of claim 1 wherein

the means for fastening comprises a threaded fastener;

the lower housing further comprises a receiving cylindrical portion comprising threads suitable for receiving the threaded fastener; and

the upper housing further comprises an aperture for receiving therethrough the threaded fastener.

10 . The anchor device of claim 9 wherein

the threaded fastener is a screw comprising a head, and

the aperture in the upper housing is countersunk to allow the head of the screw to be substantially flush with the upper housing.

11 . The anchor device of claim 10 wherein the screw is captively associated with the upper housing.

12 . The anchor device of claim 1 wherein

each cradle is partially cylindrical and adapted to receive at least a single cord,

each clamp is partially cylindrical and adapted for placement over the cord inserted into the cradle; and

each cord channel is substantially cylindrical to encase a single cord placed into the cradle;

wherein each cradle provides a cross-sectional profile of greater than half of each cylinder and extends more than halfway around each cord, and each clamp provides a cross-sectional profile of less than half of each cylinder and extends less than halfway around each cord when placed over it;

whereby each cord is press fit into each cradle with a small amount of force so the cord temporarily compresses to fit within the cradle and is held in place temporarily by the cradle until the upper housing is fastened to the lower housing.

13 . A spinal alignment apparatus, comprising

a pair of flexible cords, and

a plurality of anchor devices for securing the pair of cords to a plurality of vertebrae during a spinal alignment procedure, each of the anchor devices comprising:

a single post suitable for implantation into a vertebra, and

a cord housing coupled to the post, comprising

a lower housing monolithic with the single post, the lower housing comprising a pair of cradles, each of the cradles for insertion of one of the cords therein; and

an upper housing, separate from the lower housing, comprising a pair of clamps, each of the clamps for placement over the cords inserted into the cradles;

wherein the joining of the upper housing to the lower housing forms a pair of cord channels by the cradles and the clamps, to encase in each cord channel the cord inserted into each of the cradles; and

means for fastening the upper housing to the lower housing, causing the upper housing to press against and compress the cords within the cord channels to keep the cords clamped in and held snugly in place;

wherein

the lower housing of each anchor device further comprises a lower housing major surface located between the cradles; and

the upper housing of each anchor device further comprises an upper housing major surface located between the clamps;

wherein the upper housing major surface substantially abuts the lower housing major surface when the upper housing is joined to the lower housing and provides a stop to prevent overtightening of the upper housing to the lower housing.

14 . The spinal apparatus of claim 13 wherein

the lower housing of each anchor device further comprises at least a pair of lower housing minor surfaces; and

the upper housing of each anchor device further comprises at least a pair of upper housing minor surfaces;

wherein the upper housing minor surfaces substantially abut the lower housing minor surfaces when the upper housing is joined to the lower housing and provide a stop to prevent overtightening of the upper housing to the lower housing.

15 . The spinal apparatus of claim 14 wherein the adjoining of the upper housing major surface to the lower housing major surface and the upper housing minor surfaces to the lower housing minor surfaces provides a limit to the compression of the cords.

16 . The spinal apparatus of claim 13 wherein the cord channels of each anchor device are formed by adjoining the upper housing major surface to the lower housing major surface, the upper housing minor surfaces to the lower housing minor surfaces, and the clamps to the cradles.

17 . The spinal apparatus of claim 13 wherein

each of the cradles of each anchor device comprise a first end portion where the cord enters the cord channel, a middle portion, and a second end portion where the cord exits the cord channel, wherein the first end portion and the second end portion of each cradle each comprise an outwardly flared surface along an axis defined by the cord encased within and running along the cord channel; and

each of the clamps of each anchor device comprise a first end portion where the cord enters the cord channel, a middle portion, and a second end portion where the cord exits the cord channel, wherein the first end portion and the second end portion of each clamp each comprise an outwardly flared surface along an axis defined by the cord encased within and running along the cord channel;

whereby the outwardly flared surfaces enable the cord to bend and flex where the cord enters and exits the channel without fraying.

18 . The spinal apparatus of claim 17 wherein each cradle of each anchor device comprises a non-smooth surface suitable for gripping the at least one cord when inserted therewithin,

wherein the non-smooth surface of each cradle comprises a plurality of ribs extending substantially perpendicular to the direction in which the cord is placed within each cradle,

wherein each clamp of each anchor device comprises a non-smooth surface suitable for gripping the at least one cord when inserted therewithin, wherein the non-smooth surface of each clamp comprises a plurality of ribs extending substantially perpendicular to the direction in which the cord is placed within the cradle;

whereby a locally compressive force is imparted on the each cord so that each cord is held securely in place when the upper housing is joined to the lower housing around the cords and the cords are prevented from being pulled in either direction in the event there are stresses on the cords imparted during normal use.

19 . The spinal apparatus of claim 13 wherein

each cradle of each anchor device is partially cylindrical and adapted to receive one of the pair of cords,

each clamp of each anchor device is partially cylindrical and adapted for placement over the cord inserted into the cradle; and

each cord channel of each anchor device is substantially cylindrical to encase the cord placed into the cradle;

wherein each cradle provides a cross-sectional profile of greater than half of each cylinder and extends more than halfway around each cord, and each clamp provides a cross-sectional profile of less than half of each cylinder and extends less than halfway around each cord when placed over it;

whereby each cord is press fit into each cradle with a small amount of force so the cord temporarily compresses to fit within the cradle and is held in place temporarily by the cradle until the upper housing is fastened to the lower housing.