METHODS FOR CONNECTING A LONGITUDINAL MEMBER TO A BONE PORTION
An apparatus ( 10 ) includes a fastener ( 16 ) engageable with a bone portion to connect a longitudinal member ( 12 ) to the bone portion. A housing ( 40 ) has a first passage ( 42 ) configured to receive the longitudinal member ( 12 ) and a second passage ( 44 ) extending transverse to the first passage. The fastener ( 16 ) extends through an opening ( 50 ) in the housing ( 40 ) into the second passage ( 44 ). A longitudinal axis ( 18 ) of the fastener ( 16 ) is positionable in any one of a plurality of angular positions relative to a longitudinal axis ( 46 ) of the second passage ( 44 ). A spacer ( 60 ) received in the second passage ( 44 ) of the housing ( 40 ) is engageable with the fastener ( 16 ) and the longitudinal member ( 12 ). A member ( 70 ) applies a force to prevent relative movement between the fastener ( 16 ) and the housing ( 40 ) and permit manual movement of the fastener ( 16 ) relative to the housing ( 40 ) against the force when the longitudinal member ( 12 ) is disengaged from the spacer ( 60 ). A clamping mechanism ( 90 ) clamps the longitudinal member ( 12 ), the spacer ( 60 ), and the housing ( 40 ) to the fastener ( 16 ) to prevent movement of the fastener relative to the housing.
1 . An apparatus for connecting a rod with a bone portion, comprising:
an anchoring member having a threaded portion and a head;
a housing having a lower portion and an upper portion, the lower portion having an opening allowing only the threaded portion of the anchoring member to pass through and a socket for receipt of the head, the upper portion having an opening for receipt of the rod, the housing having a spring pocket formed therein;
a retainer ring disposed between the lower portion and the upper portion of the housing, the retainer ring having a lower spherical surface positionable along an upper surface of the head and a concave upper surface configured to engage the rod; and
a biasing element having a first proximally facing surface positionable in and contacting a surface the spring pocket of the housing and a second distally facing surface contacting a surface of the retainer ring, the biasing element applying a force upon the retainer ring which exerts a force upon the anchoring member head which exerts a force on an engagement surface of the socket of the housing; and
a fastener element securable to the upper portion of the housing for engaging the rod;
wherein the housing is configured to be moved into a predetermined position relative to said anchoring member head and maintain the predetermined position under the force exerted by the biasing element with the fastener element traversable between an unlocked position and a locked position for controlling movement of the housing relative to the anchoring member in any one of a plurality of angular positions.
2 . The apparatus of claim 1 , wherein said biasing element is an axially compressible member.
3 . The apparatus of claim 1 , wherein said biasing element is a spring member.
4 . The apparatus of claim 1 , wherein the upper portion of the housing includes a substantially U-shaped opening sized to accept said rod, wherein said concave upper surface of said retainer ring extends into said U-shaped opening.
5 . The apparatus of claim 1 , wherein said housing includes an internal thread, and said fastener element is a set screw engageable with said internal thread.
6 . The apparatus of claim 1 , wherein the biasing element positioned within the spring pocket limits proximal movement of the retainer ring and anchoring member.
7 . An apparatus for connecting a rod with a bone portion, comprising:
an anchoring member having a shank and a head;
a housing having a lower portion and an upper portion, the lower portion having an opening allowing only the shank to pass through and a socket for receipt of the head, the socket configured to receive the head in a variety of angular positions, the upper portion of the housing having a spring pocket formed therein;
a retainer ring received in said housing and having a lower surface positionable along an upper surface of the head of the anchoring member and a concave upper surface configured to engage the rod;
a spring member positionable in said spring pocket, the spring member having an upper surface in contact with an upper surface of said spring pocket and a lower surface in contact with a surface of the retainer ring; and
a fastener element securable to said upper portion of said housing for engaging the rod;
wherein the spring member is configured to apply a force onto the surface of the retainer ring, biasing the retainer ring towards the anchoring member, thereby holding a longitudinal axis of said anchoring member in any one of a plurality of desired angular positions relative to a longitudinal axis of said housing when said rod is disengaged from said retainer ring and said retainer ring engages said anchoring member head, said retainer ring and said housing being manually movable relative to each other against said force when said rod is disengaged from said retainer ring and said spring member applies said force.
8 . The apparatus of claim 7 , wherein said spring member is axially compressible.
9 . The apparatus of claim 7 , wherein the housing includes a substantially U-shaped opening sized to accept said rod, wherein the concave upper surface of said retainer ring extends into said U-shaped opening.
10 . The apparatus of claim 7 , wherein said housing includes an internal thread, and said fastener element is a threaded compression element engageable with said internal thread.
11 . The apparatus of claim 7 , wherein the spring member positioned within the housing pocket limits proximal movement of the retainer ring and anchoring member.
12 . An apparatus for connecting a rod with a bone portion, comprising:
an anchoring member having a longitudinal axis and engageable with the bone portion to connect said rod to the bone portion, the anchoring member having a shaft and a connector;
a housing having a lower portion and an upper portion, said lower portion having an opening through which only the shaft is extendable and a seat surrounding the opening for receiving the connector, the housing having a pocket formed therein;
a spacer positionable in said housing and engageable with said anchoring member and said rod; and
a biasing member positionable within the pocket between the housing and spacer;
wherein when the biasing member is disposed within the pocket, a proximal surface of the biasing member contacts an upper surface of the pocket, thereby limiting proximal movement of the spacer and anchoring member, and a distal surface of the biasing member applies a force biasing the spacer towards the anchoring member, thereby holding a longitudinal axis of said anchoring member in any one of a plurality of desired angular positions relative to a longitudinal axis of said housing when said rod is disengaged from said spacer and said spacer engages said anchoring member, said anchoring member and said housing being manually movable relative to each other against said force when said rod is disengaged from said spacer and said biasing member applies said force.
13 . The apparatus of claim 12 , wherein said biasing member is an axially compressible member.
14 . The apparatus of claim 12 , wherein said biasing member is a spring.
15 . The apparatus of claim 12 , wherein the housing includes a substantially U-shaped opening sized to accept said rod, wherein said spacer includes a concave upper surface configured to receive said rod, said concave upper surface extending into said U-shaped opening.
16 . The apparatus of claim 12 , wherein said housing includes an internal thread, and said apparatus further includes a threaded compression element engageable with said internal thread.
17 . The apparatus of claim 12 , wherein said shaft includes a helical thread.
18 . The apparatus of claim 12 , wherein the connector includes a spherical surface and the spacer has a lower spherical surface configured to match the spherical surface of the connector.