A multi-member prosthesis including first and second elongated members and a central member, said multi-member prosthesis adapted to be advanced into a pilot SI joint opening in said dysfunctional SI joint via a posterior approach, the pilot SI joint opening comprising a sacrum opening and an ilium opening and a sacrum opening. The first elongated member adapted to be press-fit into the sacrum opening and the second elongated member adapted to be press-fit into the ilium opening. The central member including first and second elongated member securing means adapted to secure the first and second elongated members thereto.

A long-pitch, helical anchor includes splines radially extending and helically progressing circumferentially around and along the arcuate length of a curved center line (central curve). The center line may progress along the curved length of the anchor with all splines meeting near the center line. In other embodiments, the center line passes along the center of a lumen or channel from which the splines extend radially along the length. A solid point acts as a cutting edge on a distal end of the anchor. All the splines converge to the center line. Installation may be with or without a stabilizing frame, such as may be used to fill gaps and promote bone growth between joined members. The anchors may be used directly to connect and provide compression between two bones or bone structures.

A method of fusing a first bone and a second bone. An abrading and harvesting device is provided that includes a needle portion having a sharpened tip. The needle portion has a central bore extending therethrough. The needle portion has a proximal end and a distal end. The sharpened tip is attached to the distal end of the needle portion. A probe is provided having an unsharpened tip portion. The probe is extended between the first bone and the second bone. The needle portion is extended over the probe by passing the proximal end of the probe through the central bore. The first bone and the second bone are abraded with the sharpened tip to cause bleeding bone to be exposed on the first bone and the second bone. A device is placed along a path formed by the needle portion between the first bone and the second bone.

A threaded implant can be provided with an elongated main body having external threads configured to thread into bone, and an internal support structure located within the external threads. The internal support structure has a helical arrangement that extends in an opposite direction to the external threads. Other threaded implants and methods are also disclosed.

Sacro-iliac joint stabilizing implants adapted for implanting across a SI joint from a dorsal approach. Methods of, and delivery tools adapted for implanting sacro-iliac joint stabilizing implants across a SI joint from a dorsal approach.

A system for treating dysfunctional SI joints that includes a multi-function bone structure prosthesis adapted to be delivered to and inserted into a dysfunctional SI joint via a posterior approach, the multi-function bone structure prosthesis, when disposed in a dysfunctional SI joint, being adapted to (i) stabilize the dysfunctional SI joint, (ii) induce proliferation, and/or growth and/or remodeling and/or regeneration of osseous tissue and, thereby, healing and arthrodesis of the dysfunctional SI joint, (iii) attenuate pain associated with the dysfunctional SI joint via neurostimulation, and (iv) monitor physiological and/or biomechanical parameters associated with the dysfunctional SI joint via one or more sensor systems.

An implant and method for posterior sacroiliac fusion having a plate for placement across the posterior surface of the sacroiliac joint, a transverse pin to slide through the plate and transverse the joint as well as provide an aperture to receive bone graft, and a sacral screw to be inserted through the plate.

Prostheses are described for stabilizing dysfunctional sacroiliac (SI) joints. The prostheses are sized and configured to be press-fit into surgically created pilot SI joint openings in dysfunctional SI joint structures. The prostheses have a pontoon shape with opposed elongated partially cylindrical sections connected by a bridge section. The partially cylindrical sections and, in some instances, the bridge section have a porous structure.

A fusion device assembly for fusion of a joint, including a first screw portion, including a first distal end, a first proximal end, a first radially outward facing surface, and a first hole, a second screw portion, including a second distal end, a second proximal end, and a second radially outward facing surface, and a section, including a first end slidably engaged with the first hole, a second end non-rotatably secured to the second distal end, and a third radially outward facing surface.

Systems are described for conducting minimally invasive medical interventions utilizing instruments and assemblies thereof to stabilize and/or fixate a dysfunctional sacroiliac (SI) joint. The systems include a drill guide having a bone dislodging member adapted to create a pilot SI joint opening in the dysfunctional SI joint through an incision comprising a length no greater than 3.0 cm; portions of the pilot SI joint opening being disposed in the sacrum and ilium bone structures. The drill guide includes a tri-mode fixation system adapted to position and stabilize the drill guide during creation of the pilot SI joint opening in the dysfunctional SI joint and delivery of the SI joint prosthesis therein. The systems also include a SI joint prosthesis configured to be inserted into the pilot SI joint opening of the dysfunctional SI joint, a prosthesis deployment assembly configured to engage the SI joint prosthesis and advance the SI joint prosthesis into the dysfunctional SI joint, and a bone harvesting assembly adapted to extract and collect dislodge bone material from the bone dislodging member after creation of the pilot SI joint opening.