Sacro-iliac joint stabilizing implants and methods of implantation

1 . A method of positioning a sacroiliac (“SI”) joint stabilization implant across an SI joint from a dorsal approach, comprising:

advancing an elongate implant positioning guide (“positioning guide”) in a dorsal trajectory into an ilium of a subject;

positioning an inner surface of the SI joint stabilization implant about an external surface of the positioning guide to restrict movement of the inner surface with respect to the external surface of the positioning guide in at least one direction;

at a time subsequent to the positioning step, advancing the implant across the SI joint while guiding the implant with the positioning guide; and

removing the positioning guide from the ilium and from a position adjacent to the inner surface.

2 . The method of claim 1 , wherein advancing the positioning guide into the ilium comprises advancing the positioning guide into the ilium between lateral and medial cortical walls of the ilium.

3 . The method of claim 2 , further comprising viewing a radiographic teardrop view image that shows a teardrop region of the ilium of the subject to help guide the positioning guide into the ilium between the lateral and medial cortical walls of the ilium.

4 . The method of claim 1 , wherein advancing the positioning guide comprises advancing the positioning guide only into the ilium.

5 . The method of claim 1 , further comprising:

at a time subsequent to positioning the positioning guide into the ilium, advancing a sacrum positioning guide into a sacrum of the subject;

positioning a second implant inner surface about an external surface of the sacrum positioning guide, wherein the implant advancing step occurs while also guiding the implant with the sacrum positioning guide; and

removing the sacrum positioning guide from the sacrum.

6 . The method of claim 5 , wherein positioning the second implant inner surface about the external surface of the sacrum positioning guide occurs prior to advancing the sacrum positioning guide into the sacrum of the subject.

7 . The method of claim 5 , further comprising advancing a second sacrum positioning guide in a dorsal trajectory into the sacrum of a subject, and positioning a third implant inner surface about an external surface of the second sacrum positioning guide to restrict movement of the implant with respect to the second sacrum positioning guide in at least one direction.

8 . The method of claim 1 , wherein the positioning step limits the amount of implant migration towards a sacrum while advancing the implant across the SI joint.

9 . The method of claim 1 , further comprising, at a time prior to positioning the inner surface of the SI joint stabilization implant about the external surface of the positioning guide, engaging a sharpened broach with the positioning guide, and advancing the broach towards the SI joint to create a space for the implant while guiding the broach with the positioning guide; and removing the broach to allow dorsal access to the space.

10 . The method of claim 1 , wherein the implant has a sharpened front section, and wherein advancing the implant into the SI joint comprises advancing the sharpened front section through bone.

11 . The method of claim 1 , wherein positioning the inner surface of the SI joint stabilization implant about the external surface of the positioning guide comprises positioning an annular inner surface of the implant completely around a proximal region of the positioning guide.

12 . The method of claim 1 , wherein positioning the inner surface of the SI joint stabilization implant about the external surface of the positioning guide comprises positioning an arcuate inner surface of the SI joint stabilization implant around a proximal region of the positioning guide.

13 . The method of claim 1 , further comprising advancing a second ilium positioning guide in a dorsal trajectory into the ilium of a subject, and positioning a second inner surface of the SI joint stabilization implant about the second ilium positioning guide to restrict movement of the implant with respect to the second ilium positioning guide in at least one direction.

14 . A method of positioning a sacroiliac (“SI”) joint stabilization implant across an SI joint from a dorsal approach, comprising:

advancing an elongate ilium positioning guide in a dorsal trajectory into an ilium of a subject;

advancing an elongate sacrum positioning guide in a dorsal trajectory into a sacrum of the subject;

positioning a first inner surface of the SI joint stabilization implant about an external surface of the ilium positioning guide to restrict movement of the first inner surface with respect to the ilium positioning guide in at least one direction;

positioning a second inner surface of the SI joint stabilization implant about an external surface of the sacrum positioning guide to restrict movement of the second inner surface with respect to the sacrum positioning guide in at least one direction;

at a time subsequent to the positioning steps, advancing the implant across the SI joint while guiding the implant with the ilium positioning guide and with the sacrum positioning guide;

removing the ilium positioning guide from the ilium; and

removing the sacrum positioning guide from the sacrum.

15 . The method of claim 14 , wherein advancing the elongate ilium positioning guide occurs prior in time to advancing the elongate sacrum positioning guide.

16 . The method of claim 14 , wherein advancing the elongate ilium positioning guide occurs subsequent in time to advancing the elongate sacrum positioning guide.

17 . The method of claim 14 , wherein advancing the ilium positioning guide into the ilium comprises advancing the positioning guide into the ilium between lateral and medial cortical walls of the ilium.

18 . The method of claim 14 , wherein positioning the second inner surface of the SI joint stabilization implant about an external surface of the sacrum positioning guide occurs prior in time to advancing the sacrum positioning guide into the sacrum of the subject.

19 . The method of claim 14 , wherein positioning the first inner surface of the SI joint stabilization implant about the external surface of ilium positioning guide occurs prior in time to advancing the ilium positioning guide into the ilium of the subject.

20 . The method of claim 14 , further comprising advancing a second sacrum positioning guide from a dorsal approach into the sacrum of a subject, and engaging a third inner surface of the implant about the second sacrum positioning guide to restrict movement of the implant with respect to the second sacrum positioning guide in at least one direction.

21 . The method of claim 14 , wherein positioning the first inner surface of the SI joint stabilization implant about the external surface of the ilium positioning guide comprises positioning an annular inner surface over a proximal region of the ilium positioning guide.

22 . The method of claim 14 , wherein positioning the second surface of the SI joint stabilization implant about the external surface of the sacrum positioning guide comprises positioning an annular inner surface of the implant over a proximal region of the sacrum positioning guide.