Bone screw apparatus, system and method

Abstract

A bone screw apparatus, system, and method for assisting in the placement and alignment of a bone screw and for aligning bone are described. The present invention allows a surgeon to position a bone screw in a desired position and adjust a coupling element in a variety of positions and angles with respect to the bone screw.

I claim: 
     
       1. An apparatus for coupling a bone screw to a connector, comprising:
 a housing that includes:
 an aperture for receiving a connector, and 
 a base having:
 a generally flat anterior surface, 
 a generally flat posterior surface, and 
 a generally oblong opening formed by a substantially linear surface extending from the anterior surface to the posterior surface, 
 
 
 at least one polyaxial bone screw directly engaging the substantially linear surface forming the generally oblong opening, and 
 a fixation element adjustably mounted to the housing that engages both the connector and the at least one polyaxial bone screw to secure both the connector and the at least one polyaxial bone screw to the housing in a fixed position, 
 wherein the housing comprises:
 a lower housing, 
 an upper housing, and 
 wherein the upper housing is configured to receive the fixation element. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the housing comprises:
 a lower housing,   an upper housing, and   wherein the upper housing is configured to receive the fixation element.   
     
     
       3. The apparatus of  claim 1 , wherein the oblong opening includes a plurality of notches defining a plurality of slot positions. 
     
     
       4. The apparatus of  claim 1 , wherein the aperture is an oblong aperture with a major axis of the oblong opening extending substantially parallel to a major axis of the oblong aperture. 
     
     
       5. A bone screw apparatus comprising:
 a coupling element that includes:
 a housing having:
 an oblong aperture extending through the housing, and 
 a base having a generally oblong opening with a major axis of the oblong opening extending substantially parallel to a major axis of the oblong aperture, 
 
 
 a connector extending through the oblong aperture, 
 a head of a polyaxial bone screw positioned in direct engagement with a wall of the housing forming the oblong opening, and 
 a fixation element configured to secure the coupling element, connector, and bone screw in a fixed position. 
 
     
     
       6. The bone screw apparatus of  claim 5 , wherein the fixation element is a locking screw, a cam lock, a taper lock, or an interference lock. 
     
     
       7. The bone screw apparatus of  claim 5 , further comprising an elongated locking wedge securing the coupling element and the polyaxial bone screw in a fixed position. 
     
     
       8. The bone screw apparatus of  claim 7 , wherein the elongated locking wedge comprises:
 a posterior surface defining a connector channel thereon, and 
 an anterior surface defining an elongated concave channel extending substantially parallel with a major axis of the elongated locking wedge. 
 
     
     
       9. The bone screw apparatus of  claim 8 , wherein the connector channel is configured to accept the connector such that the posterior surface is in facing engagement with the connector. 
     
     
       10. The bone screw apparatus of  claim 9 , wherein the elongated concave channel is configured to contact the head of the bone screw. 
     
     
       11. The bone screw apparatus of  claim 5 , wherein the connector is a cylindrical rod, a square rod, an oval rod, a rectangular rod, or a hollow rod. 
     
     
       12. The bone screw apparatus of  claim 5 , wherein the oblong opening includes a plurality of notches defining a plurality of slot positions. 
     
     
       13. The bone screw apparatus of  claim 10 , wherein the oblong opening includes at least five slot positions. 
     
     
       14. The bone screw apparatus of  claim 5 , wherein the oblong opening is a continuous slot. 
     
     
       15. The bone screw apparatus of  claim 5 , wherein the oblong opening comprises at least one of a beveled edge and a rounded edge. 
     
     
       16. The bone screw apparatus of  claim 5 , wherein the bone screw apparatus comprises at least one additional polyaxial bone screw positioned within the oblong opening. 
     
     
       17. The bone screw apparatus of  claim 16 , wherein the polyaxial bone screws are posted polyaxial screws. 
     
     
       18. The bone screw apparatus of  claim 5 , wherein the polyaxial bone screw is a posted polyaxial screw. 
     
     
       19. The bone screw apparatus of  claim 5 , wherein the base includes:
 a generally flat anterior surface; and 
 a generally flat posterior surface, and 
 wherein the oblong opening is formed by a substantially linear surface extending from the anterior surface to the posterior surface. 
 
     
     
       20. A bone screw system comprising:
 a connector, and 
 at least two bone screw apparatuses each comprising:
 a coupling element that includes:
 an The bone screw apparatus of claim 5, wherein the oblong aperture extending extends through the coupling element and is configured to receive the connector in a plurality of positions about two dimensions within the aperture, and 
 a base having an oblong slot, 
 
 a polyaxial bone screw positioned within the oblong slot, and 
 a fixation element adjustably mounted to the coupling element that secures the coupling element, connector, and polyaxial bone screw to the coupling element in a fixed position. 
 
 
     
     
       21. A method for aligning and placing a bone screw system in bone, comprising:
 (a) providing a bone screw system that includes;
 a connector; and 
 at least a first and a second bone screw apparatus, wherein each bone screw apparatus has
 a coupling element having
 an aperture configured to allow the connector to be perpendicular to or at an angle relative to a plane extending generally parallel to the aperture; and 
 a base having an opening; 
 
 a bone screw positioned within the opening; 
 an elongated locking wedge for securing the coupling element and the bone screw in a fixed position; and 
 a fixation element that provides a securing force to the connector, the elongated locking wedge, and the bone screw, 
 
 wherein the connector extends through the aperture and wherein the fixation element is configured to secure the coupling element, elongated locking wedge, connector, and bone screw in a fixed position, 
   (b) positioning the first bone screw of the first bone screw apparatus in the opening of the first coupling element,   (c) screwing the first bone screw into bone,   (d) positioning the second bone screw of the second bone screw apparatus in the generally oblong opening of the second coupling element,   (e) screwing the second bone screw into bone,   (f) repositioning each of the first and second coupling elements relative to the first and second bone screws respectively, along the openings of the first and second coupling elements so as to align the first and second apertures of the first and second coupling elements;   (g) extending the connector through each of the aligned coupling elements and positioning the connector within the aperture of at least one of the first and second coupling elements perpendicular to or at an angle relative to the plane extending generally parallel to the aperture, and   (h) securing the alignment of the first bone screw apparatus and connector to the first bone screw by providing a securing force to the connector and the elongated locking wedge via the first fixation element, and   (i) securing the alignment of the second bone screw apparatuses and connector to the second bone screw by providing a securing force to the connector and the elongated locking wedge via the second fixation element.   
     
     
       22. A bone screw for attachment to a vertebra, comprising:
 a housing having a rod passage for accepting a rod into the housing, the rod having a longitudinal rod axis;   a bone screw carried by the housing and positionable relative to the housing from a first side of the longitudinal rod axis when the rod is in the housing to a second side of the longitudinal rod axis, along a direction generally perpendicular to the longitudinal rod axis, the housing having a surface that is complementary in shape to a head of the bone screw;   a fixation element configured to secure the bone screw to the housing in various positions along the direction generally perpendicular to the longitudinal rod axis, wherein the fixation element is carried by the housing and is configured to secure both the rod and the bone screw to the housing; and   a member, the member restricted in movement in response to rotation of the fixation element against the rod for limiting relative movement between the bone screw and the housing.   
     
     
       23. The bone screw of claim 22, wherein the head of the bone screw is disposed in the housing. 
     
     
       24. The bone screw of claim 22, wherein the bone screw is adjustably positionable in various positions within the housing along the direction generally perpendicular to the longitudinal rod axis. 
     
     
       25. The bone screw of claim 22, wherein the member limits relative translational movement between the housing and the head of the bone screw. 
     
     
       26. A method of aligning and placing a bone screw system in bone, the method comprising:
 providing an apparatus including a bone fastener having a head, a housing with an aperture extending therethrough in a first direction, and a connecting rod received in the aperture and passing through the housing;   engaging the bone fastener with a bone;   selectively adjusting the housing relative to the head of the fastener along a line perpendicular to the first direction; and   securing both the head of the fastener and the connecting rod relative to the housing with a fixation element,   wherein the housing includes an open upper end and the method further comprises passing the connecting rod along a plane from the open upper end toward a lower portion of the housing, and   wherein adjusting the housing relative to the head includes positioning the head from a first side of the plane to a second side of the plane.   
     
     
       27. A method of aligning and placing a bone screw system in bone, the method comprising:
 providing an apparatus including a bone fastener having a head, a housing with an aperture extending therethrough in a first direction, and a connecting rod received in the aperture and passing through the housing;   engaging the bone fastener with a bone;   selectively adjusting the housing relative to the head of the fastener along a line perpendicular to the first direction; and   securing both the head of the fastener and the connecting rod relative to the housing with a fixation element,   wherein the housing includes an open upper end and the method further comprises passing the connecting rod along a plane from the open upper end toward a lower portion of the housing, and   wherein securing both the head of the fastener and the connecting rod relative to the housing with a fixation element includes rotating the fixation element about an axis, the axis disposed in the plane.   
     
     
       28. The method of claim 27, wherein the apparatus further includes a member and the method further comprises limiting movement of the member in response to driving engagement of the fixation element against the connecting rod to thereby limit the head of the fastener relative to the housing. 
     
     
       29. An apparatus for a bone fixation procedure, the apparatus comprising:
 a housing including an aperture extending through the housing in a first direction;   a connecting rod received in the aperture and passing through the housing;   a bone fastener including a head and an end adapted to engage a bone, the bone fastener carried by the housing such that the head of the bone fastener is adjustably positionable in various positions within the housing along a line perpendicular to the first direction prior to securing of the connecting rod to the housing, the housing having a surface that is complementary in shape to the head of the bone fastener; and   a fixation element carried by the housing for securing both the connecting rod and bone fastener relative to the housing,   wherein the housing includes an open upper end and a portion of the aperture proximate the open upper end defines a plane for passing the connecting rod from the open upper end toward a lower portion of the housing,   wherein the head of the bone fastener is disposed within the lower portion of the housing, and   wherein the head of the bone fastener is adjustably positionable from a first side of the plane to a second side of the plane.   
     
     
       30. An apparatus for a bone fixation procedure, the apparatus comprising:
 a housing including an aperture extending through the housing in a first direction;   a connecting rod received in the aperture and passing through the housing;   a bone fastener including a head and an end adapted to engage a bone, the bone fastener carried by the housing such that the head of the bone fastener is adjustably positionable in various positions within the housing along a line perpendicular to the first direction prior to securing of the connecting rod to the housing, the housing having a surface that is complementary in shape to the head of the bone fastener; and   a fixation element carried by the housing for securing both the connecting rod and bone fastener relative to the housing,   wherein the housing includes an open upper end and a portion of the aperture proximate the open upper end defines a plane for passing the connecting rod from the open upper end toward a lower portion of the housing, and   wherein the fixation element is rotatable relative to the housing about an axis, the axis disposed in the plane.   
     
     
       31. The apparatus of claim 30, further comprising a member, the member restricted in movement in response to rotation of the fixation element for limiting movement of the head of the bone fastener relative to the housing. 
     
     
       32. A method of aligning and placing a bone screw system, the method comprising:
 providing an apparatus including a bone fastener including a head, a housing with an aperture extending therethrough in a first direction, and a connecting rod received in the aperture and passing through the housing;   engaging the bone fastener with a bone; and   selectively adjusting a location of the head of the fastener within the housing by moving the head of the fastener along a line perpendicular to the first direction,   wherein the housing includes an open upper end and the method further comprises passing the connecting rod along a plane from the open upper end toward a lower portion of the housing, and   wherein adjusting the housing relative to the head includes positioning the head from a first side of the plane to a second side of the plane.   
     
     
       33. A method of aligning and placing a bone screw system, the method comprising:
 providing an apparatus including a bone fastener including a head, a housing with an aperture extending therethrough in a first direction, and a connecting rod received in the aperture and passing through the housing;   engaging the bone fastener with a bone; and   selectively adjusting a location of the head of the fastener within the housing by moving the head of the fastener along a line perpendicular to the first direction,   wherein the housing includes an open upper end and the method further comprises passing the connecting rod along a plane from the open upper end toward a lower portion of the housing, and   wherein securing both the head of the fastener and the connecting rod relative to the housing with a fixation element includes rotating the fixation element about an axis, the axis disposed in the plane.   
     
     
       34. The method of claim 33, wherein the apparatus further includes a member and the method further comprises limiting movement of the member in response to driving engagement of the fixation element against the head of the fastener to limit movement of the head of the fastener relative to the housing. 
     
     
       35. A system for assisting in placement and alignment of a bone screw and for aligning bone, the system compromising:
 an upper housing;   a lower housing;   a locking screw disposed within the upper housing, the locking screw engageable by a first tool for rotating the locking screw within the upper housing;   a connector inserted into the lower housing; and   a bone screw having a head located within the lower housing, the head of the bone screw able to be located at a plurality of different medio-lateral positions relative the lower housing, the bone screw engageable by a second tool to rotate the bone screw with respect to the bone, the lower housing defining a surface that is complementary in shape to the head of the bone screw,   whereby rotation of the locking screw by the first tool and rotation of the bone screw by the second tool secures the position of the upper housing, the lower housing and the connector with respect to the bone,   wherein the upper housing defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane for passing the connector from the open upper end toward the lower housing, and   wherein at least a first position of the plurality of different medio-lateral positions is on a first side of the plane and at least a second position of the plurality of different medio-lateral positions is on a second side of the plane.   
     
     
       36. The system of claim 35, wherein the locking screw is rotatable by the first tool about an axis, the axis disposed in the plane. 
     
     
       37. The system of claim 35, further comprising a member, movement of the member relative to the housing being restricted in response to driving engagement of the locking screw against the connector for limiting movement of the head of the bone screw relative to the lower housing. 
     
     
       38. A bone screw apparatus comprising:
 an upper housing;   a lower housing having a slot with a plurality of slot positions and including a center slot position;   a locking screw disposed within the upper housing;   a connector extending through the lower housing; and   a bone screw extending through the lower housing and being located at one of the plurality of slot positions, at least one of the plurality of slot positions being configured to inhibit movement of the bone screw along the slot,   wherein the upper housing defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane for passing the connector from the open upper end toward the lower housing, and   wherein at least a first position of the plurality of slot positions is on a first side of the plane and at least a second position of the plurality of slot positions is on a second side of the plane.   
     
     
       39. A bone screw apparatus comprising:
 an upper housing;   a lower housing having a slot with a plurality of slot positions and including a center slot position;   a locking screw disposed within the upper housing;   a connector extending through the lower housing; and   a bone screw extending through the lower housing and being located at one of the plurality of slot positions, at least one of the plurality of slot positions being configured to inhibit movement of the bone screw along the slot,   wherein the upper housing defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane for passing the connector from the open upper end toward the lower housing, and   wherein the locking screw is rotatable relative to the upper housing about an axis, the axis disposed in the plane.   
     
     
       40. A system for assisting in placement and alignment of a bone screw and for aligning bone, the system compromising:
 a first coupling element;   a second coupling element;   a connector inserted through the first coupling element and the second coupling element and connecting the first and second coupling elements;   a first bone screw having a head located within the first coupling element, the first coupling element having a first position relative to the first bone screw for permitting the first coupling element to slide with respect to the first bone screw and having a second position relative to the first bone screw for restricting movement of the first coupling element with respect to the first bone screw, the first coupling element having a first surface that is complementary in shape to the head of the first bone screw;   a second bone screw having a head located within the second coupling element, the second coupling element having a first position relative to the second bone screw to permit the second coupling element to slide with respect to the second bone screw and having a second position relative to the second bone screw for restricting movement of the second coupling element with respect to the second bone screw; and   a plurality of locking screws each disposed within one of the first and second coupling elements, each of the locking screws having a first position permitting the connector to move with respect to the one said locking screw, each of the locking screws having a second position locking movement of the connector with respect to the one said locking screw,   wherein the first coupling element defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane for passing the connector from the open upper end toward a lower portion of the first coupling element, and   wherein the head is adjustable within the lower portion from a first side of the plane to a second side of the plane.   
     
     
       41. A system for assisting in placement and alignment of a bone screw and for aligning bone, the system compromising:
 a first coupling element;   a second coupling element;   a connector inserted through the first coupling element and the second coupling element and connecting the first and second coupling elements;   a first bone screw having a head located within the first coupling element, the first coupling element having a first position relative to the first bone screw for permitting the first coupling element to slide with respect to the first bone screw and having a second position relative to the first bone screw for restricting movement of the first coupling element with respect to the first bone screw, the first coupling element having a first surface that is complementary in shape to the head of the first bone screw;   a second bone screw having a head located within the second coupling element, the second coupling element having a first position relative to the second bone screw to permit the second coupling element to slide with respect to the second bone screw and having a second position relative to the second bone screw for restricting movement of the second coupling element with respect to the second bone screw; and   a plurality of locking screws each disposed within one of the first and second coupling elements, each of the locking screws having a first position permitting the connector to move with respect to the one said locking screw, each of the locking screws having a second position locking movement of the connector with respect to the one said locking screw,   wherein the first coupling element defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane for passing the connector from the open upper end toward a lower portion of the first coupling element, and   wherein the locking screw associated with the first coupling element is rotatable about an axis, the axis disposed in the plane.   
     
     
       42. A method for securing a connector to bone comprising:
 driving a first bone screw having a head located within a first coupling element into the bone to a first position thereby permitting the first coupling element to slide with respect to the first bone screw;   driving a second bone screw having a head located within a second coupling element into the bone to a first position thereby permitting the second coupling element to slide with respect to the second bone screw;   selectively aligning the first and second coupling elements to receive a connector by sliding the first coupling element with respect to the first bone screw and sliding the second coupling element with respect to the second bone screw;   rotating a first locking screw located in the first coupling element into engagement with the connector to secure the connector with respect to the first coupling element; and   rotating a second locking screw located in the second coupling element into engagement with the connector to secure the connector with respect to the second coupling element,   wherein the first coupling element defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane, and the method includes passing the connector along the plane from the open upper end toward a lower portion of the first coupling element, and   wherein aligning the first coupling element includes positioning the head of the first bone screw from a first side of the plane to a second side of the plane.   
     
     
       43. A method for securing a connector to bone comprising:
 driving a first bone screw having a head located within a first coupling element into the bone to a first position thereby permitting the first coupling element to slide with respect to the first bone screw;   driving a second bone screw having a head located within a second coupling element into the bone to a first position thereby permitting the second coupling element to slide with respect to the second bone screw;   selectively aligning the first and second coupling elements to receive a connector by sliding the first coupling element with respect to the first bone screw and sliding the second coupling element with respect to the second bone screw;   rotating a first locking screw located in the first coupling element into engagement with the connector to secure the connector with respect to the first coupling element; and   rotating a second locking screw located in the second coupling element into engagement with the connector to secure the connector with respect to the second coupling element,   wherein the first coupling element defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane, and the method includes passing the connector along the plane from the open upper end toward a lower portion of the first coupling element, and   wherein rotating the first locking screw includes rotating the first locking screw about an axis, the axis disposed in the plane.   
     
     
       44. A system for assisting in placement and alignment of a bone screw and for aligning bone, the system compromising:
 an upper housing;   a lower housing;   a connector inserted through the lower housing;   a bone screw having a head located within the lower housing, the head of the bone screw permitting pivotal and sliding movement of the lower housing with respect to bone screw when the lower housing is in an unlocked position relative to the bone screw, the head of the bone screw restricting pivotal and sliding movement of the lower housing with respect to bone screw when the lower housing is in an locked position relative to the bone screw, the lower housing defining a surface that is complementary in shape to the head of the bone screw;   a locking screw located within the upper housing; and   a tool for adjusting the position of the locking screw so as to cause the lower housing to move between an unlocked position relative to the bone screw and a locked position relative to the bone screw.   
     
     
       45. The system of claim 44, wherein the locking screw is rotatable relative to the upper housing about an axis, the lower housing movable relative to the head of the bone screw such that the head of the bone screw is positionable along the axis. 
     
     
       46. The system of claim 45, wherein the upper and lower housings cooperatively define an aperture for receiving the connector. 
     
     
       47. The system of claim 46, wherein a portion of the aperture defined by the upper housing allows the connector to be received by an open upper end of the upper housing and pass toward the lower housing. 
     
     
       48. The system of claim 47, wherein the portion of the aperture defined by the upper housing restricts movement of the connector during passing of the connector from the open upper end toward the lower housing to a plane. 
     
     
       49. The system of claim 48, further comprising a fixation element carried by the upper housing for securing both the connecting rod and bone fastener relative to the upper housing, the fixation element rotatable relative to the upper housing about an axis, the axis disposed in the plane. 
     
     
       50. The system of claim 44, further comprising a member, the member restricted in movement in response to rotation of the locking screw for limiting movement of the head of the bone screw relative to the lower housing. 
     
     
       51. An apparatus for coupling a bone screw to a connector comprising:
 a housing that includes:
 an aperture for receiving a connector, and a base having:
 a generally flat anterior surface; 
 a generally flat posterior surface; and 
 a generally oblong opening formed by a substantially linear surface 
 extending from the anterior surface to the posterior surface; 
 
   a polyaxial bone screw movably engaged along the substantially linear surface forming the generally oblong opening; and   a fixation element adjustably mounted to the housing that engages both the connector and the polyaxial bone screw to secure both the connector and the polyaxial bone screw to the housing in a fixed position, wherein an upper portion of the housing includes a pair of spaced apart arms for threadably receiving the fixation element.   
     
     
       52. The apparatus of claim 51, wherein the pair of spaced apart arms define a plane for passing the connector from an open upper end of the housing toward a lower end of the housing. 
     
     
       53. The apparatus of claim 52, wherein the fixation element is coupled to the housing for rotation about an axis, the axis disposed in the plane. 
     
     
       54. The apparatus of claim 51, further comprising a member, the member restricted in movement in response to rotation of the fixation element against the connector for limiting movement of a head of the bone screw relative to the housing. 
     
     
       55. A bone screw system comprising:
 a connector; and   at least two bone screw apparatuses, each bone screw apparatus comprising:
 a coupling element that includes:
 a base having an oblong slot; and 
 an oblong aperture configured to allow the connector to be perpendicular to or at an angle relative to a plane extending generally parallel to the oblong slot; 
 
 a polyaxial bone screw positioned within the oblong slot; and 
 a single fixation element adjustably mounted to the coupling element that secures the connector and polyaxial bone screw to the coupling element in fixed position, wherein the coupling element of at least one of the bone screw apparatuses includes a housing having an upper portion and a lower portion, the upper and lower portions cooperatively defining the oblong aperture such that the oblong aperture is open at an upper end thereof. 
   
     
     
       56. The bone screw system of claim 55, wherein the polyaxial bone screw includes a head, the base of the coupling element movable relative to the head. 
     
     
       57. The bone screw system of claim 55, further comprising a member, the member restricted in movement in response to rotation of the fixation element against the connector for limiting relative movement between the bone screw and the connector. 
     
     
       58. A bone screw system comprising:
 at least two bone screw housings, each housing including:
 a base having an oblong slot; and 
 an aperture perpendicular to a first plane extending generally parallel to the slot; 
   a polyaxial bone screw engageable relative to the oblong slot, at least one of the housings being movable relative to the polyaxial screw;   a connector positionably engaged within the aperture to allow a connector to be perpendicular to or at an angle relative to a plane extending generally parallel to the slot; and
 a pair of fixation elements, with one of the fixation elements adjustably mounted to each of the housings to secure the connector and bone screw to the respective housing in fixed positions, 
 wherein the connector is received into the housing a first direction, the first direction being perpendicular to the first plane, and 
 wherein the housing is movable relative to a head of the polyaxial bone screw such that the head is adjustably positionable on both a first side of the first plane and a second side of the first plane. 
   
     
     
       59. The bone screw system of claim 58, wherein the connector has a longitudinal axis and further wherein the at least one of the housings is movable relative to the polyaxial screw in a direction perpendicular to the longitudinal axis. 
     
     
       60. The bone screw system of claim 58, wherein the polyaxial bone screw has a head, the head disposed in one of the bone screw housings. 
     
     
       61. The bone screw system of claim 58, further comprising a member, the member restricted in movement in response to rotation of the fixation element against the connector for limiting relative movement between the bone screw and the housing. 
     
     
       62. An apparatus for coupling a bone screw to a connector comprising:
 a housing having an aperture and an oblong slot;   a polyaxial screw positionable within the oblong slot, the housing having a surface that is complementary in shape to a head of the polyaxial screw;   a connector positionably engaged within the aperture, the aperture being configured to allow the connector to be perpendicular to or at an angle relative to a plane extending generally parallel to the slot; and   means for fixing the connector that engages the polyaxial screw to secure both the connector and the screw in a fixed position along the oblong slot,   wherein the housing includes an upper portion and a lower portion that cooperate to define the aperture, the aperture being open at an upper end to receive the connector in a first direction such that a longitudinal axis of the connector translates within a plane as the connector moves from the upper end toward the lower portion of the housing, and   wherein the housing is movable relative to the head of the polyaxial screw such that the head is adjustably positionable on both a first side of the plane and a second side of the plane.   
     
     
       63. A system for coupling a bone screw to a connector comprising:
 a housing having an oblong slot and an aperture, the oblong slot being substantially perpendicular to the aperture;   a polyaxial screw engaged within the oblong slot, the housing being independently adjustable in relation to the polyaxial screw and having a surface that is complementary in shape to a head of the polyaxial screw; and   means for fixing the housing in relation to the polyaxial screw along multiple positions relative to the oblong slot, the means for fixing disposed in the aperture in a plane substantially perpendicular or at an angle to the oblong slot,   wherein the housing is movable relative to a head of the polyaxial screw such that the head is adjustably positionable on both a first side of the plane and a second side of the plane.   
     
     
       64. A bone screw for attachment to a vertebra, comprising:
 a housing having an upper portion, a lower portion, and a rod-receiving passage from the upper portion toward the lower portion, the rod-receiving passage having a plane along which a rod travels from the upper portion toward the lower portion;   a bone screw carried by the lower portion of the housing and movable from a first side of the plane to a second side of the plane, the housing having a surface that is complementary in shape to a head of the bone screw; and   a fixation element configured to secure the bone screw to the housing in various positions as the bone screw is moved between the first and second sides of the plane.   
     
     
       65. The bone screw of claim 64, wherein the bone screw translates from the first side to the second side in a direction generally perpendicular to the plane. 
     
     
       66. The bone screw of claim 64, further comprising a set screw received in the rod-receiving passage. 
     
     
       67. The bone screw of claim 64, wherein the head of the bone screw is disposed in the lower portion of the housing. 
     
     
       68. The bone screw of claim 66, further comprising a member, the member restricted in response to rotation of the set screw against the rod for limiting movement between the bone screw and the housing. 
     
     
       69. An apparatus for a bone fixation procedure, the apparatus comprising:
 a connecting rod;   a housing including an oblong aperture extending therethrough in a first direction;   the connecting rod received in the oblong aperture and passing through the housing;   a bone fastener including a head and an end adapted to engage a bone, the bone fastener carried by the housing such that the head of the bone fastener is adjustably positionable in various positions along a line perpendicular to the first direction prior to securing of the connecting rod to the housing, the housing having a surface that is complementary in shape to the head of the bone fastener; and   a fixation element carried by the housing for securing both the connecting rod and bone fastener relative to the housing,   wherein the housing includes an open upper end defining a rod-receiving passage through which the connecting rod passes within a plane from the open upper end toward a lower portion of the housing.   
     
     
       70. The apparatus of claim 69, wherein the head is movable relative to the housing from a first side of the plane to a second side of the plane. 
     
     
       71. The apparatus of claim 69, wherein the fixation element is a set screw received in the open upper end of the housing. 
     
     
       72. The apparatus of claim 69, wherein the open upper end of the housing includes a pair of spaced apart arms. 
     
     
       73. The apparatus of claim 69, further comprising a member, movement of the member relative to the housing is restricted in response to driving engagement of the fixation element against the connecting rod for limiting movement of the head of the bone fastener relative to the housing. 
     
     
       74. A bone screw for attachment to a vertebra, comprising:
 a housing having a rod passage for accepting a rod into the housing, the rod having a longitudinal rod axis;   a bone screw including a head that is carried by the housing and a shank that extends from the head, wherein the head of the bone screw is positionable relative to the housing from a first side of the longitudinal rod axis when the rod is in the housing to a second side of the longitudinal rod axis, along a direction generally perpendicular to the longitudinal rod axis, without rotating the shank of the bone screw about the head and without rotating the housing relative to the head of the bone screw; and   a fixation element configured to secure the bone screw to the housing in various positions along the direction generally perpendicular to the longitudinal rod axis.   
     
     
       75. The bone screw of claim 74 wherein, when the rod is in the housing, the head of the bone screw is movable from one side of the rod to another side of the rod without rotating the shank of the bone screw about the head. 
     
     
       76. The bone screw of claim 74, wherein the housing includes an upper housing defining the rod passage and a lower housing having a base which defines an opening that receives the head of the bone screw. 
     
     
       77. The bone screw of claim 76, wherein upper housing of the housing is immovably coupled to the lower housing of the housing. 
     
     
       78. The bone screw of claim 76, wherein the opening in the base of the lower housing is a slot having a length that extends along the direction generally perpendicular to the longitudinal rod axis. 
     
     
       79. A bone screw for attachment to a vertebra, comprising:
 a housing having a rod passage for accepting a rod into the housing, the rod having a longitudinal rod axis;   a bone screw including a head that is carried by the housing and a shank that extends from the head, wherein when the rod is in the housing, the head of the bone screw is translatable relative to the housing from a first side of the rod to a second side of the rod, along a direction generally perpendicular to the longitudinal rod axis; and   a fixation element configured to secure the bone screw to the housing in various positions as the head of the bone screw is translated between the first and second sides of the rod,   wherein the housing includes a base defining an opening that receives the head of the bone screw.   
     
     
       80. The bone screw of claim 79, wherein, when the rod is in the housing, the head of the bone screw is translatable from the first side of the rod to the second side of the rod without rotating the shank of the bone screw about the head. 
     
     
       81. The bone screw of claim 79, wherein the opening in the base of the housing is elongated in the direction generally perpendicular to the longitudinal rod axis to allow the head of the bone screw to translate from the first side of the rod to the second side of the rod. 
     
     
       82. The bone screw of claim 79, wherein the opening in the base of the housing has an edge that is complementary in shape to the head of the bone screw.