Systems and methods for holding and implanting bone anchors

1. A guide assembly for introducing a bone anchor, comprising:

(a) an inner sleeve comprising:

(i) a first inner arm having a first distal end and a first proximal end, and comprising a first tab with a first radial ridge at the first proximal end;

(ii) a second inner arm having a second distal end and a second proximal end, comprising a second tab with a second radial ridge at the second proximal end, and positioned opposite to the first inner arm;

(iii) a first inner slot between the first inner arm and the second inner arm;

(iv) a second inner slot between the first inner arm and the second inner arm, and positioned opposite to the first inner slot;

(v) a cap assembly coupled to the first proximal end of the first inner arm and the second proximal end of the second inner arm, which longitudinally fixed relative to the first inner arm and the second inner arm, and which is free to rotate relative to the first inner arm and the second inner arm, the cap assembly comprising:

(1) an external threaded region,

(2) an internal radial groove that is complementary to the first and second radial ridges that allows the first and second radial ridges to rotate relative to the internal radial groove, but which prevents the first and second radial ridges from translating longitudinally relative to the internal radial groove; and

(b) an outer sleeve surrounding the inner sleeve, the outer sleeve comprising:

(i) a first outer arm generally aligned with the first inner arm;

(ii) a second outer arm generally aligned with the second inner arm;

(iii) a first outer slot between the first outer arm and the second outer arm;

(iv) a second outer slot between the first outer arm and the second outer arm, and positioned opposite to the first outer slot; and

(v) a central passage having a passage proximal end and a passage distal end, comprising an internal threaded region at the passage proximal end that is complementary to the external threaded region of the cap.

2. The guide assembly of claim 1 , wherein the distal end of the outer sleeve includes a cutout between the first outer arm and second outer arm, the first distal extension and second distal extension being situated within the cutout region.

3. The guide assembly of claim 2 , wherein the cutout region is dimensioned to pass the bone anchor housing such that said housing is permitted to be introduced into the central passage from the side when the first inner arm and second inner arm are in the open position.

4. The guide assembly of claim 1 , further comprising a locking mechanism to prevent the cap assembly from rotating to move the first inner arm and second inner arm from the closed position until the locking mechanism is disengaged.

5. The guide assembly of claim 4 , wherein the locking mechanism automatically engages when the first inner arm and second inner arm move into the closed position.

6. The guide assembly of claim 1 , wherein the cap is spring biased distally.

7. The guide assembly of claim 6 , wherein the cap includes at least two apertures that receive corresponding tabs extending from the proximal body to couple the cap to the proximal body.

8. A guide assembly for introducing a bone anchor to an operative target site, the bone anchor including a housing having a pair of opposed arms defined by first and second opposed slots formed in the housing, the guide assembly comprising:

(a) an outer sleeve having

(i) a distal end,

(ii) a proximal end,

(iii) a central passage extending from the distal end to the proximal end and comprising internal threading,

(iv) a first outer arm comprising a first projection at the distal end extending into the central passage, said first projection configured to engage the first recesses formed in the housing arms,

(v) a second outer arm comprising a second projection at the distal end extending into the central passage, said second projection configured to engage the second recess formed in the housing arms,

(vi) a third slot open at the distal end positioned between the first outer arm and the second outer arm, and

(vii) a fourth slot opposite the third slot, positioned between the first outer arm and the second outer arm, and open at the distal end; and

(b) a first inner arm and a second inner arm that are moveable between an open position and a closed position;

(i) the first inner arm slidably coupled to the first outer arm such that the first inner arm translates longitudinally relative to the first outer arm, the first inner arm comprising a first longitudinally extending engagement feature,

(ii) the second inner arm slidably coupled to the second outer arm such that the second inner arm translates longitudinally relative to the second outer arm, the second inner arm comprising a second longitudinally extending engagement feature,

(iii) a fifth slot separating the first and second inner arms and aligned with the third slot,

(iv) a sixth slot separating the first and second inner arms and aligned with the fourth slot, and

(c) a proximal body threadedly engaged with the internal threading of the outer sleeve and rotatable to translate the first inner arm and second inner arm between the open and closed positions.

9. The guide assembly of claim 8 , wherein the distal end of the outer sleeve includes a cutout between the first outer arm and second outer arm, the first distal extension and second distal extension being situated within the cutout region.

10. The guide assembly of claim 9 , wherein the cutout region is dimensioned to pass the bone anchor housing such that said housing is permitted to be introduced into the central passage from the side when the first inner arm and second inner arm are in the open position.

11. The guide assembly of claim 8 , further comprising a locking mechanism to prevent the proximal body from rotating to move the first inner arm and second inner arm from the closed position until the locking mechanism is disengaged.

12. The guide assembly of claim 11 , wherein the locking mechanism automatically engages when the first inner arm and second inner arm move into the closed position.

13. The guide assembly of claim 12 , wherein the locking mechanism includes a cap coupled to the proximal body.

14. The guide assembly of claim 13 , wherein the cap is spring biased distally.

15. The guide assembly of claim 14 , wherein the cap includes at least two apertures that receive corresponding tabs extending from the proximal body to couple the cap to the proximal body.

16. The guide assembly of claim 8 , wherein the distal end of the outer sleeve includes third and fourth longitudinally extending engagement features configured to slideably engage complementary third and fourth longitudinally extending engagement features on the housing.