PIVOTAL BONE ANCHOR ASSEMBLY WITH PRE-SECUREMENT OF AN INSERT INTO A RECEIVER

1 . A medical implant assembly for securing an elongate rod to a bone of a patient with tooling and a closure top, the medical implant assembly comprising:

a shank comprising a longitudinal axis, a head at a proximal end, and a body extending distally from the head with an anchor portion configured for anchoring to the bone;

a receiver comprising a base defining a lower portion of a central bore centered about a vertical centerline axis and communicating with a bottom of the base through a bottom opening, and a pair of upright arms extending upwardly from the base with interior arm surfaces defining an open channel extending between front and back faces of the receiver and configured to receive the elongate rod, the central bore extending upward from the bottom opening through the open channel to tops of the upright arms, the central bore including a closure mating structure adjacent the tops of the upright arms configured to mate with the closure top and at least one non-resilient inwardly-protruding structure preformed into the central bore below the closure mating structure, the at least one inwardly-protruding structure extending continuously and circumferentially around the central bore between vertical planar surfaces formed into the interior arm surfaces adjacent the front and back faces of the receiver, the lower portion of the central bore configured to receive the head the shank upon its uploading through the bottom opening; and

an insert positionable into the central bore of the receiver prior to the head of the shank, the insert having an upwardly-facing saddle surface configured to engage the elongate rod, a downwardly-facing surface configured to engage the head of the shank, and outward-facing side surfaces having at least one upwardly-facing abutment surface disposed adjacent to and below the at least one inwardly-protruding structure so as to limit vertical movement of the insert within the central bore prior to and during the uploading of the head of the shank into the lower portion of the central bore through the bottom opening.

2 . The medical implant assembly of claim 1 ,

wherein the insert is configured for forced downward displacement within the central bore via direct engagement from the tooling so as to move the downwardly-facing surface of the insert into engagement with the head of the shank and the at least one upwardly-facing abutment surface of the insert further below the at least one inwardly-protruding structure in the receiver, and

wherein the at least one inwardly-protruding structure is configured to overlappingly engage a second upwardly-facing surface on the insert so as to inhibit the insert from moving back up within the central bore of the receiver.

3 . The medical implant assembly of claim 1 and further comprising a resilient retainer, wherein the resilient retainer is configured to capture the head of the shank within the lower portion of the central bore upon the uploading of the head of the shank through the bottom opening.

4 . The medical implant assembly of claim 3 , wherein the lower portion of the central bore includes an expansion chamber region and the resilient retainer is configured to expand within the expansion chamber region to capture the head of the shank upon the uploading of the head of the shank through the bottom opening.

5 . The medical implant assembly of claim 3 , wherein when the head of the shank is captured by the resilient retainer, the shank is pivotal with respect to the receiver prior to locking the medical implant assembly with the closure top.

6 . The medical implant assembly of claim 1 , further comprising at least one downwardly-facing abutment surface on the outward-facing side surfaces of the insert configured to engage the at least one inwardly-protruding structure to limit downward displacement of the insert prior to the uploading of the head of the shank.

7 . The medical implant assembly of claim 1 , wherein the insert is uploadable through the bottom opening into the central bore of the receiver.

8 . The medical implant assembly of claim 7 , wherein the receiver further includes vertically-aligned guide surfaces formed into the central bore between the expansion chamber region and the closure mating structure and configured to slidably engage with vertically-aligned outer surfaces of the insert, upon the uploading of the insert into the central bore, to inhibit rotation of the insert relative to the receiver.

9 . The medical implant assembly of claim 1 , wherein the at least one upwardly-facing abutment surface of the insert further comprises a lower portion of a groove configured to at least partially receive the at least one inwardly-protruding structure upon positioning the insert within the central bore of the receiver.

10 . The medical implant assembly of claim 1 , wherein the insert further comprises a cylindrical base portion having a central aperture and a pair of insert arms extending upwardly from the cylindrical base portion to define the upwardly-facing saddle surface therebetween.

11 . The medical implant assembly of claim 1 and further comprising the elongate rod and the closure top, wherein the closure top is configured for positioning entirely within the central bore of the receiver above the elongate rod and in engagement with the closure mating structure to apply a downward pressure to the elongate rod, so as to secure the elongate rod to the bone of the patient.

12 . A method of assembling a medical implant assembly configured for securing an elongate rod to a bone of a patient via tooling and a closure top, the method comprising:

positioning an insert into a central bore of a receiver,

a receiver comprising a base defining a lower portion of the central bore centered about a vertical centerline axis and communicating with a bottom of the base through a bottom opening, and a pair of upright arms extending upwardly from the base with interior arm surfaces defining an open channel extending between front and back faces of the receiver and configured to receive the elongate rod, the central bore extending upward from the bottom opening through the open channel to tops of the upright arms, the central bore including a closure mating structure adjacent the tops of the upright arms configured to mate with the closure top and at least one non-resilient inwardly-protruding structure preformed into the central bore below the closure mating structure, the at least one inwardly-protruding structure extending continuously and circumferentially around the central bore between vertical planar surfaces formed into the interior arm surfaces adjacent the front and back faces of the receiver, the lower portion of the central bore configured to receive the head the shank upon its uploading through the bottom opening; and

the insert comprising an upwardly-facing saddle surface configured to engage the elongate rod, a curvate downwardly-facing surface, and outward-facing side surfaces having at least one upwardly-facing abutment surface disposed adjacent to the inwardly-protruding structure to limit vertical movement of the insert within the central bore; and

uploading a head of a shank into the lower portion of the central bore of the receiver through the bottom opening.

13 . The method of claim 12 , further comprising downwardly displacing the insert within the central bore via direct engagement from the tooling so as to move the downwardly-facing surface of the insert into engagement with the head of the shank and the at least one upwardly-facing abutment surface of the insert further below the inwardly-protruding structure in the receiver, and wherein the inwardly-protruding structure overlappingly engages a surface on the insert so as to inhibit the insert from moving back up within the central bore of the receiver.

14 . The method of claim 12 , further comprising capturing the head of the shank with a resilient retainer positioned within the lower portion of the central bore upon the uploading of the head of the shank through the bottom opening.

15 . The method of claim 14 , wherein the lower portion of the central bore includes an expansion chamber region and the resilient retainer is configured to expand within the expansion chamber region to capture the head of the shank upon the uploading of the head of the shank through the bottom opening.

16 . The method of claim 14 , wherein when the head of the shank is captured by the resilient retainer, the shank is pivotal with respect to the receiver prior to locking of the assembly via the closure top.

17 . The method of claim 12 , wherein at least one downward-facing abutment surface on the outward-facing side surfaces of the insert is configured to engage the inwardly-protruding structure to limit downward displacement of the insert prior to the uploading of the head of the shank through the bottom opening.

18 . The method of claim 12 , wherein positioning the insert into the central bore of the receiver further comprises uploading the insert through the bottom opening into the central bore of the receiver.

19 . The method of claim 18 , wherein the receiver further includes guide surfaces formed into the central bore below the closure mating structure and configured to slidably engage with outer surface portions of the insert upon the uploading of the insert into the central bore to limit rotation of the insert relative to the receiver.

20 . The method of claim 12 , wherein the at least one upwardly-facing abutment surface of the insert further comprises a groove portion configured to at least partially receive the inwardly-protruding structure upon positioning the insert within the central bore of the receiver.