Patent Publication Number: US-10314710-B2

Title: Methods of fusing a sacroiliac joint

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a divisional application of U.S. application Ser. No. 13/945,053 filed Jul. 18, 2013, which application claims priority to U.S. Provisional Patent Application 61/674,130, which was filed Jul. 20, 2012. 
     Application Ser. No. 13/945,053 is a continuation-in-part application of U.S. patent application Ser. No. 13/475,695, filed May 18, 2012, now U.S. Pat. No. 9,381,045, which application is a continuation-in-part application of U.S. patent application Ser. No. 13/236,411, filed Sep. 19, 2011, now U.S. Pat. No. 9,017,407, which application is a continuation-in-part of U.S. patent application Ser. No. 12/998,712 (“the &#39;712 application”), which was filed May 23, 2011, now U.S. Pat. No. 8,979,928. The &#39;712 application is the National Stage of International Patent Cooperation Treaty Patent Application PCT/US2011/000070 (the “PCT application”), which was filed Jan. 13, 2011. The PCT application claims the benefit of U.S. Provisional Patent Application 61/335,947, which was filed Jan. 13, 2010. 
     All of the aforementioned applications are hereby incorporated by reference in their entireties into the present application. 
    
    
     FIELD OF THE INVENTION 
     Aspects of the present invention relate to medical apparatus and methods. More specifically, the present invention relates to devices and methods for fusing a sacroiliac joint. 
     BACKGROUND OF THE INVENTION 
     The sacroiliac joint is the joint between the sacrum and the ilium of the pelvis, which are joined by ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. The sacroiliac joint is a synovial joint with articular cartilage and irregular elevations and depressions that produce interlocking of the two bones. 
     Pain associated with the sacroiliac joint can be caused by traumatic fracture dislocation of the pelvis, degenerative arthritis, sacroiliitis an inflammation or degenerative condition of the sacroiliac joint, osteitis condensans ilii, or other degenerative conditions of the sacroiliac joint. Currently, sacroiliac joint fusion is most commonly advocated as a surgical treatment for these conditions. Fusion of the sacroiliac joint can be accomplished by several different conventional methods encompassing an anterior approach, a posterior approach, and a lateral approach with or without percutaneous screw or other type implant fixation. However, while each of these methods has been utilized for fixation and fusion of the sacroiliac joint over the past several decades, substantial problems with respect to the fixation and fusion of the sacroiliac joint remain unresolved. 
     A significant problem with certain conventional methods for fixation and fusion of the sacroiliac joint including the anterior approach, posterior approach, or lateral approach may be that the surgeon has to make a substantial incision in the skin and tissues for direct access to the sacroiliac joint involved. These invasive approaches allow the sacroiliac joint to be seen and touched directly by the surgeon. Often referred to as an “open surgery”, these procedures have the attendant disadvantages of requiring general anesthesia and can involve increased operative time, hospitalization, pain, and recovery time due to the extensive soft tissue damage resulting from the open surgery. 
     A danger to open surgery using the anterior approach can be damage to the L5 nerve root, which lies approximately two centimeters medial to the sacroiliac joint or damage to the major blood vessels. Additionally, these procedures typically involve fixation of the sacroiliac joint (immobilization of the articular surfaces of the sacroiliac joint in relation to one another) by placement of one or more screws or one or more trans-sacroiliac implants (as shown by the non-limiting example of  FIG. 1 ) or by placement of implants into the S1 pedicle and iliac bone. 
     Use of trans-sacroiliac and S1 pedicle-iliac bone implants can also involve the risk of damage to the lumbosacral neurovascular elements. Damage to the lumbosacral neurovascular elements as well as delayed union or non-union of the sacroiliac joint by use of these procedures may require revision surgery to remove all or a portion of the implants or repeat surgery as to these complications. 
     Another significant problem with conventional procedures utilizing minimally invasive small opening procedures can be that the procedures are technically difficult, requiring biplanar fluoroscopy of the articular surfaces of the sacroiliac joint and extensive surgical training and experience. Despite the level of surgical training and experience, there is a substantial incidence of damage to the lumbosacral neurovascular elements. Additionally, sacral anomalies can further lead to mal-placement of implants leading to damage of surrounding structures. Additionally, these procedures are often performed without fusion of the sacroiliac joint, which does not remove the degenerative joint surface and thereby does not address the degenerative condition of the sacroiliac joint, which may lead to continued or recurrent sacroiliac joint pain. 
     Another significant problem with conventional procedures can be the utilization of multiple trans-sacroiliac elongate implants, which do not include a threaded surface. This approach requires the creation of trans-sacroiliac bores in the pelvis and nearby sacral foramen, which can be of relatively large dimension and which are subsequently broached with instruments, which can result in bone being impacted into the pelvis and neuroforamen. 
     The creation of the trans-sacroiliac bores and subsequent broaching of the bores requires a guide pin, which may be inadvertently advanced into the pelvis or sacral foramen, resulting in damage to other structures. Additionally, producing the trans-sacroiliac bores, broaching, or placement of the elongate implants may result in damage to the lumbosacral neurovascular elements, as above discussed. Additionally, there may be no actual fusion of the articular portion of the sacroiliac joint, which may result in continued or recurrent pain requiring additional surgery. 
     Another substantial problem with conventional procedures can be that placement of posterior extra-articular distracting fusion implants and bone grafts may be inadequate with respect to removal of the articular surface or preparation of cortical bone, the implant structure and fixation of the sacroiliac joint. The conventional procedures may not remove sufficient amounts of the articular surfaces or cortical surfaces of the sacroiliac joint to relieve pain in the sacroiliac joint. The conventional implant structures may have insufficient or avoid engagement with the articular surfaces or cortical bone of the sacroiliac joint for adequate fixation or fusion. The failure to sufficiently stabilize and fuse the sacroiliac joint with the conventional implant structures and methods may result in a failure to relieve the condition of sacroiliac joint being treated. Additionally, conventional methods of driving apart a sacrum and ilium may lead to mal-alignment of the sacroiliac joint and increased pain. 
     The inventive sacroiliac fusion system described herein addresses the problems associated with conventional methods and apparatuses used in fixation and fusion of the sacroiliac joint. 
     BRIEF SUMMARY OF THE INVENTION 
     One implementation of the present disclosure may take the form of a sacroiliac joint fusion system including a joint implant and a delivery tool. The joint implant includes at least one integral anchor configured to move relative to a body of the implant when being brought into anchoring engagement with bone defining a sacroiliac joint space in which the body of the implant is located. In one embodiment, the at least one anchor extends distally and laterally relative to a body of the implant when being brought into anchoring engagement with the bone. In another embodiment, the at least one anchor rotates relative to the body of the implant when being brought into anchoring engagement with the bone. The delivery tool is configured to support the implant off of a distal portion of the tool. The delivery tool is further configured to cause the displacement of the at least one anchor relative to the implant body so as to cause the at least one anchor to be brought into anchoring engagement with the bone. 
     While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. As will be realized, the invention is capable of modifications in various aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an anterior view of the pelvic region and a conventional method and device for stabilizing the sacroiliac joint. 
         FIG. 2A  is an isometric view of a first embodiment of a system for fusing a sacroiliac joint. 
         FIG. 2B  is the same view as  FIG. 2A , except the delivery tool and implant assembly are decoupled from each other. 
         FIG. 3  is the same view as  FIG. 2A , except the system is exploded to better illustrate its components. 
         FIGS. 4A-4C  are, respectively, proximal isometric, proximal end elevation and side elevation views of the implant assembly, which has a body that approximates or generally mimics a sacroiliac joint. 
         FIGS. 5 and 6  are distal end isometric views of the implant of the implant assembly of  FIGS. 4A-4C . 
         FIGS. 7 and 8  are proximal end isometric views of the implant of the implant assembly of  FIGS. 4A-4C . 
         FIGS. 9 and 10  are opposite lateral side plan views of the implant of the implant assembly of  FIGS. 4A-4C . 
         FIGS. 11 and 12  are, respectively, proximal and distal end elevations of the implant of the assembly of  FIGS. 4A-4C . 
         FIGS. 13 and 14  are opposite edge side elevations of the implant of the assembly of  FIGS. 4A-4C . 
         FIG. 15  is a longitudinal cross section of the implant as taken along section lines  15 - 15  in  FIG. 11 . 
         FIGS. 16A-16B  are, respectively, distal isometric and proximal isometric views of an implant assembly similar to that of  FIGS. 4A-15 , except having a rectangular body. 
         FIG. 16C  is a lateral side plan view of the rectangular implant assembly. 
         FIG. 16D  is an edge side elevation of the rectangular implant assembly. 
         FIGS. 16E and 16F  are, respectively, proximal and distal end elevations of the rectangular implant assembly. 
         FIGS. 16H and 16G  are enlarged isometric views of proximal ends of bores at proximal ends of any of the implant bodies disclosed herein as employing a screw type anchor arrangement. 
         FIG. 16I  is a distal end isometric view of an implant having a body that approximates or generally mimics a sacroiliac joint and includes a pair of keels extending from opposite lateral side surfaces. 
         FIGS. 17A and 17B  are, respectively, distal and proximal isometric views of the shaft assembly of the delivery tool of  FIGS. 2A-3 . 
         FIG. 17C  is an enlarged isometric view of the delivery tool distal end and implant assembly all shown exploded. 
         FIG. 18  is a distal isometric view of the implant retainer of the delivery tool of  FIGS. 2A-3 . 
         FIG. 19  is a distal isometric view of the delivery tool. 
         FIG. 20  is an isometric view of the implant assembly coupled to the implant retainer with the rest of the delivery tool hidden for clarity purposes. 
         FIG. 21  is an isometric view of the delivery tool and anchors with the implant hidden for clarity purposes. 
         FIGS. 22 and 23  are, respectively, distal and proximal isometric views of the implant assembly supported off of the delivery tool distal end. 
         FIG. 24  is a cross section through an anchor arm, anchor and implant bore when the implant assembly is supported off of the delivery tool distal end. 
         FIG. 25  is an inferior-posterior view of a patient wherein the delivery tool has penetrated the soft tissue to deliver the implant system into the sacroiliac joint in the hip region of the patient. 
         FIG. 26  is the same view as  FIG. 25 , except the soft tissue has been hidden to reveal only the patient&#39;s skeletal structure and the delivery tool delivering the implant system into the sacroiliac joint. 
         FIG. 27  is the same view as  FIG. 26 , except substantially enlarged to show the detail of the hip region of the patient. 
         FIG. 28  is the same view as  FIG. 27 , except still further enlarged and with the ilium hidden to more clearly shown the implantation of the implant system in the sacroiliac joint space. 
         FIG. 29  is a lateral view of a patient wherein the delivery tool has penetrated the soft tissue to deliver the implant system into the sacroiliac joint in the hip region of the patient. 
         FIG. 30  is the same view as  FIG. 29 , except the soft tissue has been hidden to reveal only the patient&#39;s skeletal structure and the delivery tool delivering the implant system into the sacroiliac joint. 
         FIG. 31  is the same view as  FIG. 30 , except substantially enlarged to show the detail of the hip region of the patient. 
         FIG. 32  is the same view as  FIG. 31 , except with the ilium hidden to more clearly shown the implantation of the implant system in the sacroiliac joint space. 
         FIG. 33  is a superior-anterior-lateral view of a patient wherein the delivery tool has penetrated the soft tissue to deliver the implant system into the sacroiliac joint in the hip region of the patient. 
         FIG. 34  is the same view as  FIG. 33 , except the soft tissue has been hidden to reveal only the patient&#39;s skeletal structure and the delivery tool delivering the implant system into the sacroiliac joint. 
         FIG. 35  is the same view as  FIG. 34 , except substantially enlarged to show the detail of the hip region of the patient. 
         FIG. 36  is a superior-posterior-lateral view of a patient wherein the delivery tool has penetrated the soft tissue to deliver the implant system into the sacroiliac joint in the hip region of the patient. 
         FIG. 37  is an enlarged view of the patient&#39;s hip region as viewed from the same perspective as  FIG. 36 , the soft tissue having been hidden to reveal only the patient&#39;s skeletal structure and the delivery tool delivering the implant system into the sacroiliac joint. 
         FIG. 38  is the same view as  FIG. 37 , except still further enlarged and with the ilium hidden to more clearly shown the implantation of the implant system in the sacroiliac joint space. 
         FIG. 39A  is a right lateral side view of a hip region of a patient lying prone, wherein the soft tissue surrounding the skeletal structure of the patient is shown in dashed lines. 
         FIG. 39B  is an enlarged view of the hip region of  FIG. 39A . 
         FIG. 40A  is a lateral-posterior view of the hip region of the patient of  FIG. 39A , wherein the patient is lying prone and the soft tissue surrounding the skeletal structure of the patient is shown in dashed lines. 
         FIG. 40B  is an enlarged view of the hip region of  FIG. 40A . 
         FIG. 41A  is a posterior view of the hip region of the patient of  FIG. 39A , wherein the patient is lying prone and the soft tissue surrounding the skeletal structure of the patient is shown in dashed lines. 
         FIG. 41B  is an enlarged view of the hip region of  FIG. 41A . 
         FIGS. 42A-42M  are each a step in the methodology and illustrated as the same transverse cross section taken along a plane extending medial-lateral and anterior posterior along section line  41 - 41  in  FIG. 41B . 
         FIG. 42N  is a similar view to  FIG. 42L , except the delivery tool in  FIG. 42N  includes an anchor arm extending off of the delivery tool to position an anchor transversely in relation to the implant assembly. 
         FIG. 43A  is a posterior-lateral view of the hip region of the patient, illustrating the placement of a cannula alignment jig. 
         FIGS. 43B-43C  are different isometric views of the cannula alignment jig. 
         FIG. 44A  is a posterior-lateral view of the hip region of the patient, illustrating the placement of a drill jig. 
         FIG. 44B  is an isometric view of the drill jig. 
         FIG. 45A  is a lateral view of the hip region of the patient, illustrating the implant implanted in the caudal region of the sacroiliac joint space. 
         FIG. 45B  is an anterior view of the hip region of the patient, illustrating the implant implanted in the caudal region of the sacroiliac joint space. 
         FIG. 45C  is an enlarged view of the implant taken along the plane of the sacroiliac joint. 
         FIG. 45D  is a transverse cross section of the implant and joint plane taken along section line  45 D- 45 D of  FIG. 45C . 
         FIG. 46  is generally the same enlarged view as  FIG. 39B , except illustrating the delivery tool being used to deliver the implant to the sacroiliac joint space. 
         FIG. 47  is the same view as  FIG. 46 , except the implant has now been fully inserted into the prepared space in the sacroiliac joint. 
         FIG. 48  is generally the same view as  FIG. 46 , except the ilium is removed to show the sacroiliac joint space boundary defined along the sacrum and the implant positioned for implantation within the joint space. 
         FIGS. 49A and 49B  are, respectively, posterior and posterior-lateral views of the implantation area and the implant assembly implanted there. 
         FIG. 50  is a plan view of a medical kit containing the components of the system, namely, the delivery tool, multiple implants of different sizes, and multiple anchor members of different sizes, wherein the system components are sealed within one or more sterile packages and provided with instructions for using the system. 
         FIG. 51  is the same transverse cross sectional view of the patient&#39;s hip as shown in  FIG. 42M , except showing the implant having structure attached thereto that will allow the implant to serve as an attachment point for structural components of a spinal support system configured to support across the patient&#39;s hip structure and/or to support along the patient&#39;s spinal column. 
         FIG. 52  is a posterior view of the patient&#39;s sacrum and ilia, wherein structural components of a spinal support system extend medial-lateral across the patient&#39;s hip structure and superiorly to support along the patient&#39;s spinal column. 
         FIG. 53  is the same view as  FIG. 52 , except having a different spanning member structure. 
         FIG. 54  is a schematic depiction of a system for fusing a joint, wherein the joint implant includes an electrode in electrical communication with a nerve sensing system. 
         FIG. 55A  is an isometric view of a second embodiment of a system for fusing a sacroiliac joint. 
         FIG. 55B  is the same view as  FIG. 55A , except the delivery tool and implant assembly are decoupled from each other. 
         FIG. 56  is the same view as  FIG. 55A , except the system is exploded to better illustrate its components. 
         FIGS. 57A-57F  are, respectively, distal isometric, proximal end elevation, first side elevation, second side elevation opposite the first side elevation, plan and distal end elevation views of the implant assembly, which has a body that is generally rectangular. 
         FIG. 58  is a distal end isometric view of the implant of the implant assembly of  FIGS. 57A-57F . 
         FIG. 59  is a lateral side plan view of the implant of the implant assembly of  FIGS. 57A-57F . 
         FIG. 60  is a proximal end elevation of the implant of the assembly of  FIGS. 57A-57F . 
         FIG. 61  is a longitudinal cross section of the implant as taken along section lines  61 - 61  in  FIG. 60 . 
         FIGS. 62A and 62B  are, respectively, distal and proximal isometric views of the shaft assembly of the delivery tool of  FIGS. 55A-56 . 
         FIG. 63  is a distal isometric view of the implant retainer of the delivery tool of  FIGS. 55A-56 . 
         FIG. 64  is a distal isometric view of the impactor of the delivery tool of  FIGS. 55A-56 . 
         FIG. 65  is a distal isometric view of the delivery tool. 
         FIG. 66  is a distal isometric view of the implant assembly coupled to the implant retainer, the impactor positioned as if having driven the anchor blades fully distal in the implant slots, and the rest of the delivery tool hidden for clarity purposes. 
         FIG. 67  is an enlarged isometric view of a distal end of the system of  FIGS. 55A-56 . 
         FIG. 68  is a distal isometric view of the impactor abutting against the proximal ends of the blade anchors, the rest of the implant assembly and delivery tool being hidden for clarity purposes. 
         FIGS. 69 and 70  are, respectively, posterior and lateral views of a patient hip region illustrating a surgical approach employing an entry point near the coccyx and the sacrotuberous ligament. 
         FIG. 71  is a posterior-lateral view of the patient hip region illustrating the delivery tool extending along the surgical approach of  FIGS. 69 and 70 . 
         FIG. 72  is an isometric view of an implant employing a rotatable or pivotable integral anchor. 
         FIGS. 73 and 74  are side elevation views of the implant of  FIG. 72 . 
         FIGS. 75 and 76  are, respectively, distal and proximal end views of the implant of  FIG. 72 . 
         FIG. 77  is an isometric view of an implant similar to that of  FIG. 72 , except employing a different anchor configuration. 
         FIGS. 78 and 79  are isometric views of the anchors employed in the implants of  FIGS. 72 and 77 , respectively. 
         FIG. 80  is an isometric view of an implant employing a rotatable or pivotable integral anchor. 
         FIGS. 81 and 82  are, respectively, side elevation and plan views of the implant of  FIG. 80 . 
         FIGS. 83 and 84  are, respectively, distal and proximal end views of the implant of  FIG. 80 . 
         FIG. 85  is an isometric view of an implant delivery tool for use with the implants of  FIGS. 72-84 . 
     
    
    
     DETAILED DESCRIPTION 
     Implementations of the present disclosure involve a system  10  for fusing a sacroiliac joint. The system  10  includes a delivery tool  20  and an implant assembly  15  for delivery to a sacroiliac joint via the delivery tool  20 . The implant assembly  15 , which includes an implant  25  and one or more anchors  30 , is configured to fuse a sacroiliac joint once implanted at the joint. The anchors  30  are integrally supported on the implant  25  and configured to laterally project from sides of the implant. By acting on the anchors  30  or a portion of the implant at a proximal end  43  of the implant  25  (e.g., by rotational or longitudinally displacing forces actuated by a component of the delivery tool  20  or by a separate tool), the anchors may be caused to deploy from the sides of the implant so as to penetrate into bone material defining the joint space in which the implant  25  is implanted. The tool  20  is configured to support the implant  25  from a distal end  35  of the delivery tool  20  for delivery of the implant into the joint space and further configured to facilitate the deployment of the anchors from the sides of the implant. Thus, the system  10  is configured such that the implant  25  can be quickly, accurately and reliably delivered to, and anchored in, a sacroiliac joint. 
     To begin a detailed discussion of a first embodiment of the system  10 , reference is made to  FIGS. 2A-3 .  FIG. 2A  is an isometric view of the system  10 .  FIG. 2B  is the same view as  FIG. 2A , except an implant assembly  15  of the system  10  is separated from a delivery tool  20  of the system  10 .  FIG. 3  is the same view as  FIG. 2A , except the system  10  is shown exploded to better illustrate the components of the system  10 . 
     As can be understood from  FIGS. 2A and 2B , the system  10  includes a delivery tool  20  and an implant assembly  15  for implanting at the sacroiliac joint via the delivery tool  20 , the implant assembly  15  being for fusing the sacroiliac joint. As indicated in  FIG. 3 , the implant assembly  15  includes an implant  25  and anchor elements  30  (e.g., bone screws, nails or other elongated bodies). As discussed below in greater detail, during the implantation of the implant assembly  15  at the sacroiliac joint, the implant  25  and anchor element  30  are supported by a distal end  35  of the delivery tool  20 , as illustrated in  FIG. 2A . In one embodiment, the distal end  35  may be fixed or non-removable from the rest of the delivery tool  20 . In other embodiments, the distal end  35  of the delivery tool  20  may be removable so as to allow interchanging of different sized or shaped distal ends  35  to allow matching to particular implant embodiments without requiring the use of a different delivery tool  20 . The delivery tool  20  is used to deliver the implant  25  into the sacroiliac joint space. The delivery tool  20  is then used to cause the anchor elements  30  to deploy or otherwise extend from the sides of the implant  25  and into the bone of the ilium and sacrum defining the sacroiliac joint. The delivery tool  20  is then decoupled from the implanted implant assembly  15 , as can be understood from  FIG. 2B . 
     To begin a detailed discussion of components of an embodiment of the implant assembly  15 , reference is made to  FIGS. 4A-4C , which are, respectively, proximal isometric, proximal end elevation, and side elevation views of the implant assembly  15 . As shown in  FIGS. 4A-4C , the implant assembly  15  includes an implant  25  and anchor elements  30 . The anchor elements  30  may be in the form of an elongated body such as, for example, a nail, rod, pin, threaded screw, etc. The anchor elements  30  are configured to be received in bores  40  defined through the implant  25 . The bores  40  extend through the implant  25  distally and laterally from a proximal end  43  of the implant  25  and are sized such that the anchor elements  30  can at least project both laterally and distally from the sides of the implant  25  as illustrated in  FIGS. 4A-4C . 
     For a detailed discussion of the implant  25 , reference is made to  FIGS. 5-15 .  FIGS. 5-8  are various isometric views of the implant  25 .  FIGS. 9 and 12  are opposite plan views of the implant  25 , and  FIGS. 11-14  are various elevation views of the implant.  FIG. 15  is an isometric longitudinal cross section of the implant  25  as taken along section lines  15 - 15  in  FIG. 11 . 
     As shown in  FIGS. 5-15 , in one embodiment, the implant  25  includes a distal or leading end  42 , a proximal or trailing end  43 , a longitudinally extending body  45 , bores  40  extending distally and laterally through the body from the proximal end  43 , a center bore  70 , a distal opening  50 , and a proximal opening  55 . In one embodiment, the implant  25  is configured to have a shape that generally mimics and even substantially fills a sacroiliac joint space. For example, as can be understood from a comparison of the plan views of the implant  25  as illustrated in  FIGS. 9 and 10  to the shape of the sacroiliac joint articular region  1044  depicted in  FIGS. 45A and 48  discussed below, the implant has an overall exterior shape that generally mimics the sacroiliac joint articular region  1044 . The anatomic implant  25  can be provided from the manufacturer in the configuration generally as shown in the  FIGS. 5-15 . 
     As illustrated in  FIGS. 7 and 8 , the implant  25  includes a proximal end  43  for being removably coupled to the extreme distal end  35  of the delivery tool  20 . Specifically, in one embodiment, the implant proximal end  43  includes a center bore  70  that extends distally through the implant from the proximal end  43 . The center bore  70  may be a blind hole in that it only has a single opening, which is at the proximal end  43 . Alternatively, as best understood from  FIG. 15 , the center bore  70  may be configured as a hole that communicates between the implant proximal end  43  and implant proximal opening  55 . The center bore  70  may be threaded or otherwise configured so as to allow mechanical engagement with a distal end  220  of a retainer member  95  of the delivery tool  20 , the retainer member  95  being used to secure the implant  25  off of the distal end  35  of the delivery tool  20 , as described in detail below. Additionally, the center bore  70  may extend distally across void  55  and continue distally further into body  45 . Accordingly, e.g., a bone graft can be placed in void  55  where the graft may have a bore similar to and in alignment with center bore  70  to allow retainer member  95  to pass there through, thereby retaining the graft in place during implantation of implant  25 . Subsequently, e.g., bone marrow aspirate may be injected via center bore  70  into the bone graft material, which if substantially solid may have passages cut into it which communicate between the external surfaces of the graft and the graft&#39;s bore. In one embodiment, the center attachment bore  70  has a diameter of between approximately 2 mm and approximately 10 mm, with one embodiment having a diameter of approximately 5 mm. 
     As shown in  FIGS. 9 and 10 , the implant  25  includes a long portion  7100  and a short portion  7101  perpendicularly oriented to the long portion. The long portion transitions smoothly into the short portion via a small radius  7102  and a large radius  7103  opposite the small radius. The large radius and small radius form an elbow region  7104  of the implant. The large radius forms a heal region  7105  of the implant, and opposite the heal region is a blunt toe region  7106  forming a right angle with a base region  7107  that is generally parallel to the proximal end  43 . These regions  7105 - 7107  form the distal end  42  of the implant  25 . 
     As can be understood from  FIGS. 9 and 10 , the long portion  7100  has a length D 1  of between approximately 25 mm and approximately 45 mm, and the short portion  7101  has a length D 2  of between approximately 20 mm and approximately 40 mm. The small curve  7102  has a radius of between approximately 2.5 mm and approximately 16 mm, with one embodiment having a radius of approximately 8 mm, and the large curve  7103  has a radius of between approximately 8 mm and approximately 20 mm, with one embodiment having a radius of approximately 15 mm. The implant body  45  has an overall width D 3  of between approximately 10 mm and approximately 20 mm and an overall length D 4  of between approximately 35 mm and approximately 60 mm. The toe projects from the immediate lateral side edge  7150  of the implant body  45  by a distance D 5  of between approximately 8 mm and approximately 20 mm, with one embodiment having a distance D 5  of approximately 15 mm. 
     The implant  25  can be configured such that the body  45  of the implant is a generally continuous solid surface with the exception of the bores  40 ,  70  extending through portions of the body  45 . However, as indicated in  FIGS. 5-10 and 15 , the body  45  of the implant  25  may have one or more openings or voids defined in the body  45 . For example, an opening or void  50  may be defined in a distal region of the implant body  45 , and another opening or void  55  may be defined in a proximal region of the implant body  45 . The voids  50 ,  55  may be packed with bone growth material prior to the implant  25  being delivered into the sacroiliac joint space. 
     As indicated in  FIGS. 5-15 , the implant body  45  includes side edge surfaces  7150  that extend between the proximal end  43  and the distal end  42 . These side edge surfaces  7150  and the similar side edge surfaces associated with the small curve  7102 , the large curve  7104 , the toe  7106 , the distal end  42  and proximal end  43  combine to define side edge surface boundary  7110  (indicated in  FIG. 15 ) that extends unbroken and unitary through all of the above-mentioned regions of the implant, thereby forming an outer boundary that may at least somewhat resemble the sacroiliac joint space and more fully occupy the joint space than more linearly shaped rectangle and cylindrical implant embodiments. 
     As illustrated in  FIGS. 5-15 , in one embodiment, the implant body  45  includes generally planar lateral side surfaces  7060 . In some embodiments, the lateral side surfaces  7060  may be generally spaced apart by a distance or body thickness that is generally continuous over the entirety of the surfaces  7060 . However, as can be understood from  FIGS. 13 and 14 , in some embodiments, the distance or body thickness may taper from a greater thickness D 4  in the long portion  7100  and a lesser thickness D 5  in the short portion  7101 . In one embodiment, the greater thickness D 6  may be between approximately 3 mm and approximately 10 mm, and the lesser thickness D 7  may be between approximately 3 mm and approximately 6 mm. 
     In one embodiment, the planar lateral side surfaces  7060  may be substantially smooth. However, in other embodiments, as indicated in  FIGS. 9-14 , the planar lateral side surfaces  7060  may have multiple parallel ridges  7061  that extend longitudinally along the long portion  7100  and may be serrated with notches  7062  oriented so as to prevent proximal migration of the implant  25  once implanted in the sacroiliac joint. The anti-migration features  7062  are generally evenly distributed along the planar surfaces  7060 . While the anti-migration features  7062  are depicted as being notches  7062  defined in the longitudinally extending ribs or ridges  7061 , in other embodiments the anti-migration features  7062  may be in the form of other types of surface texturing or protrusions in the form of cylinders, trapezoids, squares, rectangles, etc. Further, although the anti-migration features  7062  are depicted in the form of unidirectional serrated notches  7062  in ridges  7061  on the planar lateral side surfaces  7060  the implant  25 , the invention is not so limited and, as to particular embodiments, can be configured to have said features  7062  arranged in multiple directions, unidirectional, or a combination of multiple direction on some surfaces of the implant and unidirectional on other surfaces of the implant. Accordingly, the features  7062  can be so arranged on the various surfaces of the implant so as to prevent undesired migration in particular directions due to the forces present at the sacroiliac joint  1000 . 
     As indicated in  FIGS. 7 and 8 , longitudinally extending rectangular notches  6514  may be defined in the planar lateral side surfaces  7060 . As described below, such notches  6514  may interact with members  140  forming part of the delivery tool distal end  35  so as to help retain the implant  25  on the distal end  35  and to prevent the implant from rotating relative to the distal end  35  when the retaining rod threaded distal end  220  is being threaded into or out of the center bore  70 . 
     As can be understood from  FIGS. 4A and 5-10 , in one embodiment, the bores  40  extend distally and laterally from a proximal end  43  of the implant  25  to begin day lighting distally in the proximal void  55  and eventually exit the implant body  45  laterally as grooves or portions of bores defined in the planar lateral side surface  7060 . Since the bores  40  are oriented so as to extend distally and laterally from the proximal end  43  and, further, since the anchors  30  have sufficient length, the anchors  30  project both laterally and distally from the planar lateral side surfaces  7060  of the implant  25 , as illustrated in  FIGS. 4A-4C . 
     In summary, as can be understood from  FIGS. 5-15 , in one embodiment, a sacroiliac joint fusion implant  25  includes a proximal end  43 , a distal end  42  generally opposite the proximal end, and side edge surfaces  7150  extending between the proximal and distal ends and defining a long portion of the implant  7100  and a short portion  7101  of the implant. The long portion is longer than the short portion and the two portions extend in directions generally perpendicular to each other. The proximal end terminates proximally in a generally blunt end and the distal end terminates distally in a generally blunt end  7106  facing in a direction generally perpendicular of the direction faced by the generally blunt end of the proximal end. The generally blunt end of the proximal end is configured to releasably couple to an implant delivery system. An offset distance between the side edge surfaces  7150  is substantially greater than a thickness of the implant as defined by an offset distance between the planar lateral side surfaces  7060 . One side edge surface  7150  transitions between the long and short portions  7100 ,  7101  via a first curved portion  7103  and the another side edge surface  7150  transitions between the long and short portions via a second curved portion  7102  having a radius smaller than the first curved portion. The cumulative exterior side edge border surface  7110  defines a shape resembling a shape of an adult human sacroiliac joint as viewed in a direction perpendicular a plane of the sacroiliac joint. For example, the cumulative exterior side edge border surface  7110  defines a shape resembling a boot for a human foot. 
     In one embodiment, the implant  25  may be machined, molded, formed, or otherwise manufactured from stainless steel, titanium, ceramic, polymer, composite, bone or other biocompatible materials. The anchor member  30  may be machined, molded, formed or otherwise manufactured from similar biocompatible materials. 
     In some embodiments, the implant  25  may be substantially as described above with respect to  FIGS. 4-15 , except the implant  25  may have an overall shape that is something other than shaped to mimic the sacroiliac joint. For example, as shown in  FIGS. 16A-16F , which are various isometric, plan, and elevational views of an alternative embodiment of an implant assembly  15  that may be employed with the delivery tool  20  of  FIGS. 2A-3 , the implant  25  may have a rectangular shape. Other than the overall shape of the implant  25  of the implant assembly  15  of  FIGS. 16A-16F  being different than the overall shape of the implant  25  of the implant assembly  15  of  FIGS. 4A-4C  and the implant  25  of  FIGS. 16A-16F  having only a single void  50  as opposed to two voids  50 ,  55 , all other features of the implant assemblies  15  are essentially the same for both implant assemblies  15 . While the implant  25  are shown herein to have a joint-shaped configuration and a rectangular shape, in other embodiments the implant  25  may have other shapes such as cylindrical, trapezoidal, triangular, etc. and still be useable with the delivery tool  20  of  FIGS. 2A-3  and have anchors oriented and deployable as described above with respect to  FIGS. 4A-16F . 
     As illustrated in  FIGS. 16H and 16G , which are enlarged isometric views of proximal ends of bores  40  at proximal ends  43  of any of the implant bodies  25  disclosed herein as employing a screw type anchor  30 , the bores  40  may be configured to have a retainer arrangement that acts against the anchors  30  when in the bores  40  to prevent the anchors  30  from backing out of the bores  40 . 
     As indicated in  FIG. 16H , in one embodiment, the proximal end of a bore  40  may have a disk-shaped seat  310  having a center hole  315  that forms the remainder of the extent of the bore  40 . The disk-shaped seat  310  has a plurality of arcuate members  320  distributed along an inner circumferential boundary  325  of a rim  330  of the disk-shaped seat  310 . There may be five or more or less arcuate members  320  distributed generally evenly about the inner circumferential surface  325  of the rim  330 . 
     In one embodiment, each arcuate member  320  has ends  332  that intersect the inner circumferential surface  325  of the rim  330 , with a center point  335  of the arcuate member  320  that is offset or spaced apart from inner circumferential surface  325  of the rim  330 . Thus, in one embodiment, the arcuate members  320  may be deflectable so as to allow the head of the anchor member  30  to pass between the center points  335  of the members  330  as the head of the anchor member  30  is seated in the seat  310 . As a result, the arcuate members  320  can act against the head of the anchor member  30  to prevent the anchor member from working its way out of the bore  40  and opening  315  of the implant  25 , thereby serving as an anchor member locking mechanism. 
     Other anchor member locking mechanisms may be employed. For example, as illustrated in  FIG. 16H , the bore  40  includes a cantilevered abutment arm  335  defined proximal end  43  of the implant body  25  via a series of parallel arcuate slots  340 . In one embodiment, a face  345  of the abutment arm  335  is deflectable and biased radially inward of the inner circumferential surface  350  of the bore  40  such that when the anchor member  30  is extended through the bore  40 , the face  345  abuts against the anchor member to prevent the anchor member from working its way out of the bore  40  of the implant  25 , thereby serving as an anchor member locking mechanism. 
     In other embodiments of the implant, other anchor member locking mechanisms may be employed including, for example, set screws supported off of the implant body to engage the anchor  30  when received in a bore  40 . 
     The particular embodiments of  FIGS. 4A-16F  depict implant assemblies  15  having an implant  25  with a generally planar body  45  such that the width and length of the body  45  are substantially greater than the thickness of the body  45  and the planar body  45  is generally free of any substantial features of the body extending away from the planar lateral side surfaces  7060 . However, in other embodiments, the implant body  45  of the present disclosure may have the anchoring arrangement illustrated in  FIGS. 4A-16F  and further be configured to have a shape and/or radially extending wings as described with respect to any of the many implant body embodiments described in U.S. patent application Ser. No. 13/475,695, which was filed May 18, 2012 and is hereby incorporated by reference in its entirety. For example, as seen in  FIG. 16I , which is a distal end isometric view of the implant  25 , the body  45  is similar to the implant  25  of  FIGS. 5-15 , except the body  45  includes a pair of keels, fins, planar members, or wing members  56  extending generally perpendicularly outward from the planar lateral side surfaces  7060 . The body  45  may include voids  50 ,  55  as in other embodiments of the implant  25 . As seen in the figure, the keels  56  may extend along a longitudinal axis of the body  45  of the implant and may extend from opposite planar lateral side surfaces  7060  such that the keels  56  are generally coplanar with each other. For example, the keels  56  opposite each other generally exist in the same plane. More specifically, planar faces of a first keel  56  are generally coplanar with the planar faces of a second keel  56  opposite the first keel  56 . As seen in the figure, the keels  56  are generally positioned centrally on the respective planar lateral side surfaces  7060  so as to be generally equidistant between a top and bottom side edge surface  7150 . A width of the keels  56  may be smaller than a width of the body  45  of the implant  25  between the opposite planar lateral side surfaces  7060 . 
     The particular embodiments of  FIGS. 4A-16F  depict implant assemblies  15  having an implant  25  with a generally planar body  45  such that the width and length of the body  45  are substantially greater than the thickness of the body  45  and the planar body  45  is generally free of any substantial features of the body extending away from the planar lateral side surfaces  7060 . However, in other embodiments, the implant body  45  of the present disclosure may have the anchoring arrangement illustrated in  FIGS. 4A-16F  and further be configured to have a shape and/or radially extending wings as described with respect to any of the many implant body embodiments described in U.S. patent application Ser. No. 13/475,695, which was filed May 18, 2012 and is hereby incorporated by reference in its entirety. 
     Alternatively, the implant may be configured as disclosed in U.S. Provisional Patent Application 61/520,956 which is entitled “Sacroiliac Joint Implant System,” which was filed Jun. 17, 2011 and the corresponding Patent Cooperation Treaty patent application PCT/US12/42823. 
     To begin a detailed discussion of components of an embodiment of the delivery tool  20 , reference is again made to  FIGS. 2A-3 . As shown in  FIG. 2A , the delivery tool  20  includes a distal end  35  and a proximal end  80 . The distal end  35  supports the components  25 ,  30  of the implant assembly  15 , and the proximal end  80  is configured to be grasped and manipulated to facilitate the implantation of the implant assembly  15  in the sacroiliac joint. 
     As illustrated in  FIG. 3 , the delivery tool  20  further includes a shaft assembly  85 , a handle  90 , an implant retainer  95 . As shown in  FIGS. 17A and 17B , which are, respectively, distal and proximal isometric views of the shaft assembly  85 , the shaft assembly  85  includes the handle,  90 , a tubular elongated body  100 , a distal implant engagement end  105 , and anchor guides  160 . The handle  90  is coupled on a proximal end  110  of the tubular elongated body  100 . The tubular elongated body  100  includes a lumen  115  through which the implant retainer  95  extends, as described below. The anchor guides  160  are tubular structures mounted on opposite sides of the distal implant engagement end  105 . The anchor guides  160  may have other shapes that are complementary with the shape of anchors  30  having shapes. For example, anchor guides  160  may have a rectangular in cross section in order to correctly align an anchor which is rectangular in cross section with an implant bore  40  which is also rectangular in cross section. 
     As shown in  FIG. 17C , which is an enlarged isometric view of the delivery tool distal end  35  and implant assembly  15  all shown exploded, the distal implant engagement end  105  includes a distal face  130  that is located between the distal openings of the lumens  132  of the anchor guides  160  and offset distally extending members  140 . The members  140  have opposed planar faces  142  that are each configured to be matingly received by the respective notches  6514  of the implant  25  when the proximal end  43  of the implant  25  is received in an implant receiving space  143  defined by the distal face  130  and opposed planar faces  142 . 
     As illustrated in  FIG. 18 , which is a distal isometric view of the implant retainer  95 , the implant retainer  95  includes a longitudinal cylindrical member  210 , a handle  215  on a proximal end of the longitudinal cylindrical member  210 , and an implant engagement feature  220  on a distal end the longitudinal cylindrical member  210 . As can be understood from  FIG. 19 , which is a distal isometric view of the delivery tool  20 , the member  210  of the implant retainer  95  extends through the lumen  115  of the body  100 , the engagement feature  220  distally extending from the lumen  115  when a distal face of the retainer handle  215  is abutting against a proximal face of the shaft assembly handle  90 . 
     As can be understood from  FIG. 20 , which is an isometric view of the implant assembly  15  coupled to the implant retainer  95  with the rest of the delivery tool  20  hidden for clarity purposes, in one embodiment, the implant engagement feature  220  is in the form of a threaded shaft for engaging complementary threads in the center bore  70 , thereby securing the implant proximal face  43  against the distal face  130  of the distal implant engagement end  105 , the members  140  being received in the notches  6514 , as can be understood from  FIG. 2A . 
     As illustrated in  FIG. 21 , which is a distal isometric view of the delivery tool  20  with the anchors  30  loaded in the anchor guides  160  of the delivery tool  20 , the anchor guides  160  are oriented such that the longitudinal axes of the anchor guide lumens  132  extend both distally and laterally. Thus, anchors  30  loaded in the anchor guide lumens  132  are oriented so as to be guided along a trajectory that is both distal and laterally outward relative to a longitudinal axis of the tubular member  100 . 
       FIGS. 22 and 23  are, respectively, distal and proximal isometric views of the implant assembly  15  supported off of the delivery tool distal end  35 .  FIG. 24  is a cross section through an anchor arm  160 , anchor  30  and implant bore  40  when the implant assembly  15  is supported off of the delivery tool distal end  35 . As can be understood from  FIGS. 22-24 , when the implant  25  is coupled to the delivery tool distal end  35 , the longitudinal axes of the anchor guide lumens  132  and the respective bores  40  are coaxially aligned such that the trajectory of an anchor  30  positioned in an anchor guide lumen  132  extends through the respective bore  40 . Thus, as indicated in  FIG. 24 , the anchor  40  automatically tracks into the respective bore  40  upon a wrench or other tool being applied to the distal or head end  144  of the anchor screw  30  via the proximal anchor lumen opening  146 , as can be understood from  FIG. 23 . 
     For a general overview of a method of implanting the above-described implant system  15  in a caudal region  1086  of the sacroiliac joint articular region  1044  of a patient  1001  via the above-described delivery tool  20  through a caudal access, reference is now made to  FIGS. 25-38 .  FIGS. 25, 29, 33 and 36  are, respectively, inferior-posterior, lateral, superior-anterior-lateral, and superior-posterior-lateral views of the patient  1001 . As shown in  FIGS. 25, 29, 33 and 36 , the delivery tool  20  penetrates the soft tissue  1003  of the patient  1001  to extend into the patient&#39;s hip region  1002  via a tissue penetration in a superior region of one of the patient&#39;s buttocks. In doing so, the delivery tool  20  can be seen to be oriented such that a longitudinal axis of the shaft  100  of the delivery tool  20  has a generally anterior trajectory. 
       FIG. 26  is the same view as  FIG. 25 , except the soft tissue  1003  has been hidden to reveal only the patient&#39;s skeletal structure  1006 , and  FIG. 27  is the same view as  FIG. 26 , except substantially enlarged to show the detail of the hip region  1002  of the patient. As illustrated in  FIGS. 26 and 27 , the position and orientation of the implant system  15  deployed in the sacroiliac joint  1000  can be understood with respect to common anatomical features of the sacrum  1004  and ilium  1005 , such anatomical features including the posterior superior iliac spine  2004 , posterior inferior iliac spine  2006 , greater sciatic notch  2008 , ischial spine  2010 , and tubercle of iliac crest  2012 . Other anatomical features shown include the posterior inferior access region  2016  of the sacroiliac joint articular region, the superior end  2018  on the sacroiliac joint line, the posterior inferior overhang  2020  of the posterior superior iliac spine, the inferior end  2022  on the sacroiliac joint line that is at approximately the superior beginning of the greater sciatic notch, and the lateral anterior curved boundary  2024  of the sacrum  1004 . 
     Additional understanding regarding the position and orientation of the implant system  15  deployed in the sacroiliac joint  1000  can be gained from a review of  FIGS. 30 and 34 , which are, respectively, the same views as  FIGS. 29 and 33 , except the soft tissue  1003  has been hidden to reveal only the patient&#39;s skeletal structure  1006 . Still further understanding can be obtained from  FIGS. 31 and 35 , which are the same respective views as  FIGS. 30 and 34 , except substantially enlarged to show the detail of the hip region  1002  of the patient.  FIG. 37  is a substantially enlarged view showing the detail of the hip region of the patient, except correlating to the view of the patient depicted in  FIG. 36 . 
       FIGS. 26 and 27  make it possible to understand the position and orientation of the delivery tool elements when the delivery tool distal end  35  is coupled to the proximal end of the implant  25  when the implant is positioned in the sacroiliac joint  1000 . For example, the position and location of delivery tool elements such as the handle  90 , shaft  100 , implant retainer handle  215  and anchor guide  160  can be understood from  FIGS. 26 and 27 .  FIGS. 30, 31, 34, 35 and 37  also provide understanding regarding the position and orientation of the delivery tool elements when the delivery tool distal end  35  is coupled to the proximal end of the implant  25  when the implant is positioned in the sacroiliac joint  1000 . 
       FIGS. 28, 32 and 38  are the same respective views as  FIGS. 27, 31 and 37 , except still further enlarged and with the ilium hidden to more clearly shown the implantation of the implant system  15  in the sacroiliac joint  1000 . The distal and lateral projection of the lateral anchor  30  from the implant  25  is clearly indicated in each of  FIGS. 28, 32 and 38 . The coupling of the proximal end of the implant  25  to the distal end of the delivery tool guide portion  160  can also be clearly seen in  FIGS. 28, 32 and 38 . 
     To begin a more detailed discussion regarding the step-by-step methodology associated with employing the above-described delivery tool  20  in implanting the above-described implant  25  in the sacroiliac joint  1000  of a patient  1001 , reference is first made to  FIGS. 39A-41B  to identify the bone landmarks adjacent, and defining, the sacroiliac joint  1000 .  FIG. 39A  is a right lateral side view of a hip region  1002  of a patient  1001  lying prone, wherein the soft tissue  1003  surrounding the skeletal structure  1006  of the patient  1001  is shown in dashed lines.  FIG. 39B  is an enlarged view of the hip region  1002  of  FIG. 39A . As illustrated in  FIGS. 39A and 39B , a lateral view of the patient&#39;s hip region  1002  reveals certain features of the ilium  1005 , including the anterior superior iliac spine  2000 , the iliac crest  2002 , the posterior superior iliac spine  2004 , the posterior inferior iliac spine  2006 , the greater sciatic notch  2008  extending from the posterior inferior iliac spine  2006  to the ischial spine  2010 , and the tubercle of iliac crest  2012 . The sacroiliac joint articular region  1044  is shown in dashed lines. A posterior inferior access region  2016  of the sacroiliac joint articular region  1044  has a superior end  2018  on the sacroiliac joint line  2019  that is between approximately 0 mm and approximately 40 mm inferior the posterior inferior overhang  2020  of the posterior superior iliac spine  2004 . The posterior inferior access region  2016  of the sacroiliac joint articular region  1044  has an inferior end  2022  on the sacroiliac joint line that is at approximately the intersection of the posterior inferior iliac spine  2006  with the lateral anterior curved boundary  2024  of the sacrum  1004 . In other words, the posterior inferior access region  2016  of the sacroiliac joint articular region  1044  has an inferior end  2022  on the sacroiliac joint line that is at approximately the superior beginning of the greater sciatic notch  2008 . 
       FIG. 40A  is a lateral-posterior view of the hip region  1002  of the patient  1001  of  FIG. 39A , wherein the patient  1001  is lying prone and the soft tissue  1003  surrounding the skeletal structure  1006  of the patient  1001  is shown in dashed lines.  FIG. 40B  is an enlarged view of the hip region  1002  of  FIG. 40A . As shown in  FIGS. 40A and 40B , a lateral-posterior view of the patient&#39;s hip region  1002  reveals the same features of the sacrum  1004  and ilium  1005  as discussed above with respect to  FIGS. 39A and 396B , except from another vantage point. The vantage point provided via  FIGS. 40A and 40B  provides further understanding regarding the posterior inferior access region  2016  of the sacroiliac joint articular region  1044  and superior end  2018  and inferior end  2022  of the posterior inferior access region  2016  relative to nearby anatomical features, such as, for example, the posterior inferior overhang  2020  of the posterior superior iliac spine  2004 , the intersection of the posterior inferior iliac spine  2006  with the lateral anterior curved boundary  2024  of the sacrum  1004 , and the superior beginning of the greater sciatic notch  2008 . 
       FIG. 41A  is a posterior view of the hip region  1002  of the patient  1001  of  FIG. 39A , wherein the patient  1001  is lying prone and the soft tissue  1003  surrounding the skeletal structure  1006  of the patient  1001  is shown in dashed lines.  FIG. 41B  is an enlarged view of the hip region  1002  of  FIG. 41A . As shown in  FIGS. 41A and 41B , a posterior view of the patient&#39;s hip region  1002  reveals the same features of the sacrum  1004  and ilium  1005  as discussed above with respect to  FIGS. 39A and 39B , except from yet another vantage point. The vantage point provided via  FIGS. 41A and 41B  provides yet further understanding regarding the posterior inferior access region  2016  of the sacroiliac joint articular region  1044  and superior end  2018  and inferior end  2022  of the posterior inferior access region  2016  relative to nearby anatomical features, such as, for example, the posterior inferior overhang  2020  of the posterior superior iliac spine  2004 , the intersection of the posterior inferior iliac spine  2006  with the lateral anterior curved boundary  2024  of the sacrum  1004 , and the superior beginning of the greater sciatic notch  2008 . 
     Now that the relevant anatomical landmarks have been identified with respect to  FIGS. 39A-41B , the methodology associated with employing any of the above-described delivery tools  20  in implanting any of the above-described implants  25  in the sacroiliac joint  1000  of a patient  1001  can be discussed. In doing so, reference will be made to  FIGS. 42A-42M , which are each a step in the methodology and illustrated as the same transverse cross section taken in along a plane extending medial-lateral and anterior posterior along section line  42 - 42  in  FIG. 41B . In this cross section, articular surfaces  1016  are covered by a thick layer of articular cartilage with a joint space existing between them, the  FIGS. 42A-42M  are simplified for illustrative purposes and do not show these features to scale. Now referring primarily to  FIG. 42A , an embodiment of the method can include the step of placing a patient under sedation prone on a translucent operating table (or other suitable surface). The sacroiliac joint  1000  can be locally anesthetized to allow for injecting a radiographic contrast  1046  (as a non-limiting example, Isoview  300  radiographic contrast) under fluoroscopic guidance into the inferior aspect of the sacroiliac joint  1000  to outline the articular surfaces  1016  of the sacroiliac joint  1000 ) defined between the sacrum  1004  and ilium  1005 , the sacroiliac joint  1000  having an interarticular region  1044 . Injection of the radiographic contrast  1046  within the sacroiliac joint  1000  can be accomplished utilizing a tubular member  1047 )(such as a syringe needle) having first tubular member end  1048  which can be advanced between the articulating surfaces  1016  of the sacroiliac joint  1000  and having a second tubular member end  1049  which removably couples to a hub  1050 . The hub  1050  can be configured to removably couple to a syringe barrel  1051  (or other device to contain and deliver an amount of radiographic contrast  1046 ). In the example of a syringe barrel  1051 , the syringe barrel  1051  can have an internal volume capable of receiving an amount of the radiographic contrast  1046  sufficient for outlining the articular surfaces  1016  of the sacroiliac joint  1000 , for example, under lateral fluoroscopy. A plunger  1052  can be slidingly received within the barrel  1051  to deliver the radiographic contrast  1046  through the tubular member  1047  into the sacroiliac joint  1000 . The tubular member  1047  can have a gauge in the range of about 16 gauge and about 20 gauge and can further be incrementally marked on the external surface to allow determination of the depth at which the first needle end  1048  has advanced within the sacroiliac joint  1000 . As the first needle end  1048  advances into the sacroiliac joint  1000  the radiographic dye  1046  can be delivered from within the syringe barrel  1051  into the sacroiliac joint  1000  to allow visualization of the sacroiliac joint  1000  and location of the tubular needle  1047  within the sacroiliac joint  1000 . 
     Now referring primarily to  FIG. 42B , once the first tubular member end  1048  has been sufficiently advanced into the sacroiliac joint  1000  and the articular surfaces  1016  of the sacroiliac joint  1000  have been sufficiently visualized, the hub  1050  can be removed from the tubular member  1047  leaving the tubular member  1047  fixed within the sacroiliac joint  1000  as an initial guide for tools subsequently used to locate or place the sacroiliac joint implant  25  non-transversely between the articulating surfaces  1016  of the sacroiliac joint  1000  (e.g., locate the implant  25  non-transversely to the joint plane  1030  generally defined by the articulating surfaces  1016  of the interarticular region  1044  of the sacroiliac joint  1000 ) or in removal of a portion of the sacroiliac joint  1000  within the region defined by the articular surfaces  1016  to generate an implant receiving space  1029  (see  FIG. 42H ). Alternately, one or more guide pins  1013  can be inserted along substantially the same path of the tubular member  1047  for fixed engagement within the sacroiliac joint  1000  and used in subsequent steps as a guide(s). 
     Now referring primarily to  FIG. 42C , a small incision  1053  can be made in the skin at the posterior superior (or as to certain embodiments inferior) aspect of the sacroiliac joint  1000 , extending proximal and distal to the tubular member  1047  along the line of the sacroiliac joint  1000  to provide a passage to access the interarticular space between the articulating surfaces  1016  (see  FIG. 42B ) of the sacroiliac joint  1000 . More specifically, as can be understood from  FIGS. 39A-41B , in one embodiment, the small incision  1053  can be made along the joint line  2019  of the sacroiliac joint  1000  in the tissue covering the posterior inferior access region  2016  of the sacroiliac joint articular region  1044 . A cannulated probe  1054  can be slidingly engaged with the tubular member  1047  (or guide pin  1013 ) extending outwardly from the sacroiliac joint  1000  (while the sacroiliac joint may be shown in the figures as being substantially linear for illustrative purposes, it is to be understood that the normal irregular features of the sacroiliac joint have not been removed). The cannulated probe  1054  can have a probe body  1054  of generally cylindrical shape terminating in a spatulate tip  1055  at the end advanced into the sacroiliac joint  1000 . A removable cannulated probe handle  1056  couples to the opposed end of the probe body  1054 . The spatulate tip  1055  can be guided along the tubular needle  1047  or guide wire  1013  into the posterior portion of the sacroiliac joint  1000  and advanced to the anterior portion of the sacroiliac joint  1000  under lateral fluoroscopic visualization. The cannulated probe handle  1056  can then be removed providing the generally cylindrical probe body  1054  extending outwardly from the sacroiliac joint  1000  through the incision  1053  made in the skin. 
     Alternatively, probe  1054  can be used to guide, advance or place a needle, guide wire or other instrument up to, near, or into the joint. 
     Additionally, in particular embodiments, probe handle  1056  or the opposed end of the probe body  1054 , or both, can be configured to have an interference fit or a luer lock hub to communicate with a syringe barrel  1051  in order to advance contrast, in situ curable biocompatible materials, stem cells, or etc. through the cannulated probe  1054  or cannulated probe handle  1056 . 
     Now referring primarily to  FIG. 42D , a passage from the incision  1053  (see  FIG. 42C ) to the sacroiliac joint  1000  can be generated by inserting a cannula  1057  into the incision. A soft tissue dilator  1058  having a blunt end  1059  can be advanced over the probe body  1054 , or a plurality of soft tissue dilators of increasing size, until the blunt end  1059  of the soft tissue dilator  1058  and the corresponding cannula end contact the posterior aspect of the sacroiliac joint  1000 . More specifically, as can be understood from  FIGS. 39A-41B , in one embodiment, the ends of the dilator  1058  and cannula  1057  contact the joint line  2019  of the sacroiliac joint  1000  at the posterior inferior access region  2016  of the sacroiliac joint articular region  1044 . The soft tissue dilator  1058  can be removed from within the cannula  1057 . The external surface of the cannula  1057  can be sufficiently engaged with the surrounding tissue to avoid having the tissue locate with in the hollow inside of the cannula  1057 . A non-limiting embodiment of the cannula  1057  provides a tubular body having substantially parallel opposed side walls which terminate in a radius at both ends (lozenge shape) into which a plurality of different jigs can be inserted. Alternatively, as a non-limiting example, according to particular embodiments, cannula  1057  and corresponding dilators  1058  and alignment jigs  1060  can be configured to have tubular bodies with an elliptical or circular cross section. 
     In some embodiments, the cannula  1057  may be additionally configured to have within or near its walls a light source such as, for example, a fiber optic or a LED light source to assist in visualization of the working area. Also, in some embodiments, irrigation and suction tubing may communicate with the inside passage of cannula  1057 . 
     Now referring primarily to  FIGS. 43A-43C , a cannula alignment jig  1060  can be advanced over the probe body  1054  (or guide pins  1013 ) and received within the cannula  1057 . Substantially, identical cross hairs  1063 ,  1064  can be disposed on the upper jig surface  1065  and the lower jig surface  1066 . Alignment of the cross hairs  1063 ,  1064  under x-ray with the sacroiliac joint  1000  can confirm that the cannula  1057  has proper orientation in relation to the paired articular surfaces  1016  of the sacroiliac joint  1000 . The cannula  1057  properly oriented with the paired articular surfaces  1016  can then be disposed in fixed relation to the sacroiliac joint by placement of fasteners through the cannula  1057  into the sacrum  1004  or the ilium  1005 . A handle extending from a part of the cannula may be configured to allow fixturing to an operating table. 
     Now referring to  FIGS. 44A and 44B , a first drill jig  1067  can be advanced over the probe body  1054  (or guide pins  1013 ) and received within the cannula  1057 . The probe body  1054  (or guide pins  1013 ) extending outwardly from the sacroiliac joint  1000  passes through a drill guide hole  1068  of the first drill jig  1067  (or a plurality of guide pins  1013  can extend through a corresponding plurality of guide pin holes  1069 ). The drill guide hole  1068  can take the form of a circular hole as shown in the Figures, a slot, or other configuration to restrict the movement of the drill bit  1062  (see  FIG. 42E ) within the drill jig  1060  and provide a guide for a drill bit  1062  in relation to the sacroiliac joint  1000 . Guide pin holes  1069  can receive guide pins which can be positioned between the articular surfaces  1016  of the sacroiliac joint  1000  to demarcate the zone of desired treatment or safe working zones while using, for example, lateral fluoroscopy. As a non-limiting example, a first guide pin  1013  can be advanced through a first guide pin hole  1069 , or alternatively a guide pin  1013  is first inserted into the sacroiliac joint  1000  and subsequently a guide jig  1067  is advanced over the guide pin  1013 , the first guide pin  1013  can enter near inferior end  2022  of the posterior inferior access region  2016  of the sacroiliac joint articular region  1044  via the sacroiliac joint line  2019  to border a portion of the greater sciatic notch  2008  thereby allowing a medical person, computer guided surgical system, or other observer to more easily highlight under x-ray a border which should not be crossed during the procedure due to the presence of nerve and other structures. Additionally, as a non-limiting example, first guide pin  1013  can configured as an electrode, insulated from the operator and the patient&#39;s soft tissues, and may be connected to a monitor to signal to an operator or surgeon when implant  25 , configured with a stimulating electrode (NM), as discussed below, comes into contact with first guide pin. Similarly, a second guide pin  1013  can be placed in another guide pin hole  1069  to demarcate a second limit to a desired zone of treatment, or safe working zone. For example, a second guide pin  1013  can enter near the superior end  2018  of the posterior inferior access region  2016  of the sacroiliac joint articular region  1044  via the sacroiliac joint line  2019  to be positioned to border an area of the sacroiliac joint  1000  such as a transition zone between the extra-articular  3007  (see  FIG. 48 ) and the interarticular region  1044  which, for example, has been highlighted by contrast material as above described. 
     Now referring to  FIG. 42E , a cannulated drill bit  1070  can be advanced over the probe body  1054  and within a drill guide hole  1068  (see  FIGS. 44A and 44B ) of the first drill jig  1067 . The cannulated drill bit  1070  under fluoroscopic guidance can be advanced into the interarticular region  1044  between the articulating surfaces  1016  of the sacroiliac joint  1000  to produce a first bore  1071  (shown in broken line) to a determined depth. As to certain embodiments of the method, an amount of articular cartilage or other tissues from between the articular surfaces  1016  of the sacroiliac joint  1000  can be removed sufficient to allow embodiments of the sacroiliac joint implant  25  to be implanted in replacement of the removed articular cartilage or tissue. Because the method removes the degenerative articular cartilage or tissue between the articular surfaces  1016  of the sacroiliac joint  1000 , the articular surfaces  1016  of the sacroiliac joint  1000  can remain intact or substantially intact allowing the sacroiliac joint implant  25  to be non-transversely located between the articular surfaces  1016  of the sacroiliac joint  1000 . Understandably, other instruments can be utilized separately or in combination with a cannulated drill bit  1062  for the removal of articular cartilage or tissue between articular surfaces  1016  such as: endoscopy tools, box chisels, side cutting router bits, burs, flexible burs and bits, hole saws, curettes, lasers (such as C02, Neodymium/Y AG (yttrium-aluminum-garnet), argon, and ruby), electrosurgical equipment employing electromagnetic energy (the cutting or heating electrode can be a fine micro-needle, a lancet, a knife, a wire or band loop, a snare, an energized scalpel, or the like) where, e.g., the energy transmitted can be either monopolar or bipolar and operate with high frequency currents, for example, in the range of about 300 kHz and about 1000 kHz whether as pure sinusoidal current waveform where the “crest factor” can be constant at about 1.4 for every sinus waveform, and a voltage peak of approximately 300 V to enable a “pure” cutting effect with the smallest possible coagulation effect or as amplitude modulated current waveforms where the crest factor varies between 1.5 and 8, with decreasing crest factors providing less of a coagulation effect. Electrosurgical waveforms may be set to promote two types of tissue effects, namely coagulation (temperature rises within cells, which then dehydrate and shrink) or cut (heating of cellular water occurs so rapidly that cells burst). The proportion of cells coagulated to those cut can be varied, resulting in a “blended” or “mixed” effect. Additionally, a fully rectified current, or a partially rectified current, or a fulguration current where a greater amount or lateral heat is produced can be employed to find the articular surfaces of the joint and aid in advancing a probe or guide wire into a position in between the articulating surfaces. These currents can effectively degrade the cartilage and allow advance into the joint without grossly penetrating much beyond the cartilage. 
     Now referring to  FIG. 42F , as to certain embodiments of the invention, the first drill jig  1067  can be removed from within the cannula  1057  and a second drill jig  1072  can be advanced over the probe body  1054  and received within the cannula  1057 ; however, the invention is not limited to any particular number of drill jigs and as to certain embodiments of the method the first drill jig  1067  can include all the required drill guide hole(s)  1068  (or slots or other configurations of the drill guide) and as to other embodiments of the method a plurality of drill jigs can be utilized in serial order to provide all the drill guide holes  1068 . As to the particular embodiment of the invention shown by the Figures, the first drill jig  1067  can provide one or more additional drill guide holes  1068  which guide in relation to the first bore  1071  a second or more cannulated drills  1062  of the same or different configuration to be inserted within and advanced into the sacroiliac joint  1000  to produce a second bore  1073  (generally shown in broken line as  1071 / 1073 ) or a plurality of bores within the sacroiliac joint  1000  spaced apart in predetermined pattern to allow removal of sufficient articular cartilage  1016  or other tissue from the interarticular space of sacroiliac joint  1000  for placement of embodiments of the sacroiliac joint implant  25  within the region defined by and between the paired articular surfaces  1016  of the sacroiliac joint  1000 . As to certain methods of the invention, the first drill jig  1067  or the second drill jig  1072  or a plurality of drill jigs can be utilized in serial order to remove a portion of the sacroiliac joint  1000  for generation of an implant receiving space  1029  (see, for example,  FIG. 42H ). As these embodiments of the method, articular cartilage or other tissues and sufficient subchondral bone can be removed from between the articular surfaces  1016  of the sacroiliac joint  1000  sufficient to allow placement of certain embodiments of the sacroiliac joint implant  25  and one or more radial member receiving channels  1074  can be cut into at least one of the articular surfaces  1016  of said sacroiliac joint  1000  sufficient to receive other embodiments of the sacroiliac implant  25 . The one or more radial member receiving channels  1074  can be cut a depth into the subchondral, cortical bone or cancellous bone of the sacrum  1004  or ilium  1005 . 
     Now referring primarily to  FIG. 42G , in a subsequent step, the last in the serial presentation of drill jigs  1067 ,  1072  can be removed from within the cannula  1057  and a broach jig  1075  can be advanced over the probe body  1054  to locate within the cannula  1057 . The broach jig  1075  can include a broach guide hole  1076  which receives a first broach end  1077  of a cannulated broach  1078  advanced over the probe body  1054 . The first broach end  1077  can have a configuration which can be advanced into the sacroiliac joint  1000 . As to certain embodiments of the method, the first broach end  1077  can be adapted to remove an amount of articular cartilage and other tissue from between the articular surfaces  1016  within the articular region  1044  of the sacroiliac joint  1000  for non-transverse placement of a sacroiliac joint implant  25  having an elongate body  45 , or having an elongate body  45  and other features (e.g., members radially extending from the body  45 ) between the articular surfaces  1016  of the sacroiliac joint  1000 . As to other embodiments of the method, the cannulated broach  1078  can remove a sufficient portion of the sacroiliac joint  1000  to generate an implant receiving space  1029  to receive embodiments of the sacroiliac joint implant  25  having an elongate body  45  or an elongate body  45  and one or more radial members adapted for non-transverse placement between the articular surfaces  1016  or adapted to extend into the bone of the sacrum  1004  or the ilium  1005 . 
     As a non-limiting example,  FIG. 42G  shows a broach  1078  configured to remove a portion of the sacroiliac joint  1000  to produce an implant receiving space  1029  (shown in  FIG. 42H ) to receive embodiments of the sacroiliac joint implant  25  having an elongate body  45  that extends between the articular surfaces  1016  of the sacroiliac joint  1000  and one or more anchors  30  that extend from the implant body  45  into the adjacent sacrum  1004  and ilium  1005 . 
     Now referring primarily to  FIGS. 45A-45D , the implant receiving space  1029  and the sacroiliac joint implant  25  can be configured having related dimension relations such that placement of the sacroiliac joint implant  25  within the implant receiving space  1029  disposes the sacrum  1004  and the ilium  1005  in substantially immobilized relation and substantially avoids alteration of the positional relation of the sacrum  1004  and the ilium  1005  from the normal condition, or avoids driving together or driving apart the sacrum  1004  from the ilium  1005  outside of or substantially outside of the normal positional relation. An intention in selecting configurations of the sacroiliac joint implant  25  and the implant receiving space  1029  being immobilization of the sacrum  1004  in relation to the ilium  1005  while maintaining the sacroiliac joint  1000  in substantially normal or substantially normal positional relation, or returning the sacroiliac joint  1000  to a substantially normal positional relation to correct a degenerative condition of the sacroiliac joint  1000 . 
     As a non-limiting example, configurations of an implant receiving space  1029  allow embodiments of the sacroiliac joint implant  25  to be placed non-transversely between the caudal portion  1086  of the articular surfaces  1016  of the sacroiliac joint  1000 . In one embodiment of the sacroiliac joint implant  25 , the implant body  45  is located within a correspondingly configured implant receiving space  1029  to engage at least a portion of the bone of the ilium  1005  or sacrum  1004 . In some embodiments, members may radially extend from the implant body  45  to extend into a portion of the bone  1073  of the sacrum  1004  and the ilium  1005 . As to those embodiments of the sacroiliac joint implant  25  which having such radial members, the implant receiving space  1029  can further include one or more radial member receiving channels, which correspondingly allow the radial members to extend into the bone  1073  of the sacrum  1004  or the ilium  1005  (whether subchondral, cortical, cancellous, or the like), or impact of the sacroiliac joint implant  25  into the implant receiving space  1029  without the radial member receiving channels can forcibly urge such radial members into the bone  1073  of the sacrum  1004  and the ilium  1005 . While not depicted in the accompanying figures of the present application, such radial members and radial member receiving channels are discussed in detail in U.S. patent application Ser. No. 12/998,712 (which is incorporated herein in its entirety) and can be readily employed with any of the implant embodiments disclosed herein. 
     As indicated in  FIGS. 45B-45D , anchor members  30  (such as threaded members) can be inserted through the bores  40  in the implant  25  and into the sacrum  1004  and ilium  1005  to fix the location of the fixation fusion implant  25  within the implant receiving space  1029 . 
     While the preceding discussion is given in the context of the implant  25  being implanted non-transversely in the caudal portion  1086  of the sacroiliac joint  1000 , in other embodiments, the implant  25  may be implanted in other locations within the sacroiliac joint. For example, as disclosed in U.S. patent application Ser. No. 12/998,712, which is incorporated herein by reference, in some embodiments, the implant  25  may be implanted non-transversely in the cranial portion  1087  (see  FIG. 45A ) of the sacroiliac joint  1000  by the similar procedures or steps as above described with the incision and generation of the passage to the superior articular portion of the sacroiliac joint  1000 . The implant may also be implanted in the sacroiliac joint in such a manner so as to extend between the cranial and caudal portions, as also disclosed in U.S. patent application Ser. No. 12/998,712. 
     To begin a discussion of employing the delivery tool  20  to implant the implant  25  in the sacroiliac joint  1000  once the implant receiving space  1029  has been created, reference is made to  FIGS. 42I, and 46 .  FIG. 46  is generally the same enlarged view as  FIG. 39B . As shown in FIGS.  FIGS. 42I and 46 , once the implant receiving space  1029  has been created as discussed above with respect to  FIGS. 42A-42H , the implant  25  can be supported off of the distal end  35  of the delivery tool  20  and positioned such that the distal end  42  of the implant  25  begins to enter the sacroiliac joint articular region  1044  via the posterior inferior access region  2016 , which is described in detail above with respect to  FIGS. 39A-41B . As can be understood from  FIG. 46 , in entering the sacroiliac joint space, the implant  25  is oriented such that its body  45  is oriented generally parallel to, and aligned with, the sacroiliac joint line  2019 . In other words, the body  45  is generally located within the joint plane  1030  such that its faces  7060  are generally parallel to the joint plane  1030  and its side edge faces  7150  project in a directions that extends along the joint plane  1030  (see, e.g.,  FIGS. 45C and 45D ). The longitudinal axis of the shaft  100  of the delivery tool  20  has a generally anterior trajectory that is located within the joint plane  1030 . Alternatively, according to particular embodiments, as a non-limiting example, the longitudinal axis of the shaft  100  of the delivery tool  20  can have a trajectory which can be defined as being generally lateral or, in particular embodiments, generally posterior. In some embodiments, when the implant  25  is being delivered into the joint space, the shaft  100  can be said to be at least one of generally superior or cephald the sciatic notch. 
       FIG. 47  is the same view as  FIG. 46 , except the implant  25  has now been fully inserted into the prepared space  1029  in the sacroiliac joint  1000 . As illustrated in  FIGS. 42J and 47 , the implant  25  is fully received in the prepared sacroiliac space  1029  such that the body  45  is oriented generally parallel to, and aligned with, the sacroiliac joint line  1030  such that its faces  7060  are generally parallel to the joint plane  1030  and its side edge faces  7150  project in a directions that extends along the joint plane  1030  (see, e.g.,  FIGS. 45C and 45D ). As can be understood from  FIG. 42J , the longitudinal axis of the implant  25  and the longitudinal axis of the shaft  100  of the delivery tool  20  may be coaxially aligned with each other and generally located in the sacroiliac joint plane  1030 . 
       FIG. 48  is generally the same view as  FIG. 46 , except the ilium  1005  is removed to show the sacroiliac joint space boundary  3000  defined along the sacrum  1004  and outlining the sacroiliac joint articular region  1044 , the implant  25  positioned for implantation within the sacroiliac joint articular region  1044 . As shown in  FIG. 48 , the sacroiliac joint space boundary includes an inferior boundary segment  3002 , an anterior boundary segment  3004 , a superior boundary segment  3006 , and a posterior boundary segment  3008 . The inferior boundary segment  3002  is immediately adjacent, and extends along, the sciatic notch  2024 . 
     The inferior boundary segment  3002  and anterior boundary segment  3004  intersect to form an anterior-inferior corner  3010 . The anterior boundary segment  3004  and superior boundary segment  3006  intersect to form an anterior-superior corner  3012 . The superior boundary segment  3006  and posterior boundary segment  3008  intersect to form a superior-posterior corner  3014 . The posterior boundary segment  3008  and posterior inferior access region  2016  intersect to form a superior-posterior corner  3016  of the posterior inferior access region  2016 . The inferior boundary segment  3002  and posterior inferior access region  2016  intersect to form an inferior-posterior corner  3018  of the posterior inferior access region  2016 . 
     The inferior boundary segment  3002  extends between corners  3010  and  3018 . The anterior boundary segment  3004  extends between corners  3010  and  3012 . The superior boundary segment  3006  extends between corners  3012  and  3014  and provides an access into the cranial portion  1087  of the sacroiliac joint. The posterior boundary segment  3008  extends between corners  3014  and  3016 . The posterior inferior access region  2016  extends between corners  3016  and  3018  and provides an access into the caudal region  1086  of the sacroiliac joint. The posterior boundary segment  3008  separates articular region  1044  and extra-articular region  3007 , which includes the sacral fossa on the sacrum  1004  and the corresponding iliac tuberosity on the ilium  1005  and defined by the extra-articular region boundary  3009 . 
     As shown in  FIG. 48 , the implant  25  is inserted via the distal end  35  of the shaft  100  of the delivery tool  20  into the caudal region  1086  of the sacroiliac joint articular region  1044 . As shown via the implant  25  and shaft  100  shown in solid lines, in one embodiment, the implant  25  enters the posterior inferior access region  2016 , and is further advanced into the caudal region  1086  of the sacroiliac joint articular region  1044 , in an orientation such that the shaft  100  and side edge faces  7150  of the implant body  45  face in a direction that extends along the joint plane  1030  (see, for example,  FIGS. 42I-42J  and  FIGS. 45C and 45D ) and the longitudinally extending side edge face  7150  of the implant body  45  next to the inferior boundary segment  3002  is generally parallel to, and immediately adjacent to, the inferior boundary segment  3002 . Thus, the distal end  42  of the implant is heading generally perpendicular to, and towards, the anterior boundary segment  3004 . 
     As shown in  FIG. 48  via the implant  25  and delivery tool shaft  100  shown in dashed lines, in one embodiment, the implant  25  enters the posterior inferior access region  2016 , and is further advanced into the caudal region  1086  of the sacroiliac joint articular region  1044 , in an orientation such that the delivery tool shaft  100  and side edge faces  7150  of the implant body  45  face in a direction that extends along the joint plane  1030  (see, for example,  FIGS. 42I-42J  and  FIGS. 45C and 45D ) and the longitudinally extending side edge face  7150  of the implant body  45  next to the inferior boundary segment  3002  is somewhere between being generally parallel to the inferior boundary segment  3002  (as illustrated by the solid-lined implant  25  in  FIG. 48 ) or forming an angle AJ with the inferior boundary segment  3002  of up to approximately 50 degrees. Thus, the distal end  42  of the implant shown in dashed lines can be said to head anywhere from generally perpendicular to, and towards, the anterior boundary segment  3004  to heading generally towards the superior-anterior corner  3012 , or points in between. 
     In one embodiment, the implant  25  may be first directed into the joint space as illustrated by the solid-lined implant  25  in  FIG. 48  after which the implant  25  is rotated within the joint space to be positioned somewhere between, and including, angled position depicted by the dashed-lined implant  25 . In other embodiments, the implant  25  may be first directed into the joint space as illustrated by the dashed-lined implant  25  in  FIG. 48  after which the implant  25  is rotated within the joint space to be positioned somewhere between, and including, the parallel position depicted by the solid-lined implant  25 . 
     As can be understood from  FIGS. 4A-15, 45 and 48  where the implant  25  has a body  45  that is configured to have a shape that generally mimics and even substantially fills a sacroiliac joint space, depending on the needs of the patient and the treatment plan devised by the physician, generally the entirety of both the long portion  7100  and short portion  7101  of the implant body  45  may reside substantially in the caudal portion  1086  of the sacroiliac joint space (as indicated in  FIG. 48 ). Alternatively, the long portion  7100  of the implant body  45  may reside in the caudal portion  1086  of the sacroiliac joint space and the short portion  7101  may extend into the cranial portion  1087  of the sacroiliac joint space (as indicated in  FIG. 45 ), the small radius  7102  and large radius of the implant body  45  being generally located at the generally right-angled intersection between the cranial portion  1087  and the caudal portion  1086  of the sacroiliac joint. 
     As can be understood from  FIG. 42K , with the delivery tool  20  still coupled to the implant and the implant  25  located within the sacroiliac joint space as shown in  FIG. 45A-45D or 48 , the anchor members  30  are positioned in the guide lumens  132  of the delivery tool distal end  35  (see  FIGS. 17C and 21 ) in preparation for driving the anchors  30  through the respective bores  40  of the implant body  45 . 
     As can be understood from  FIGS. 22-24 and 45B-45D , a distal end of a driving tool (e.g., screw driver) is engaged in turn with a proximal end of the anchor member  30  (e.g., screw) residing in the respective guide lumen  132  to drive the anchor  30  through the implant bores  40  and into the adjacent bone of the sacrum and ilium as reflected in  FIG. 42L . Specifically, the driving tool is used to drive (e.g., a screw) each anchor  30  through its respective guide lumen  132  and into the respective implant anchor bore  40  aligned with the respective guide lumen  132  such that the distal region of the anchor  30  extends both distally and laterally from the respective side face  7060  of the implant body  45  into the respective bone (i.e., ilium and sacrum) bordering the sacroiliac joint space as depicted in  FIG. 42L . 
     Prior to anchor member implantation, guide lumen  132  may be further configured with a needle guide sleeve to allow for guided advancement of a needle into the bone of a sacrum or ilium for aspiration of bone marrow which may be used in subsequent steps during the course of the procedure or for administration into the patient at a later date after the procedure has been completed (e.g., the aspirate may be manipulated and stem cells isolated and cultured for administration into the patient to treat a medical condition). 
     As shown in  FIG. 42M , once the implant assembly formed of the implant  25  and anchor members  30  is secured at the implantation site such that the implant  25  is located in the prepared space  1029  of the sacroiliac joint space and the anchor members  30  extend from the implant body bores  45  into the bone of the ilium  1005  and sacrum  1004 , the distal end  35  of the delivery tool  20  can be decoupled from the implant proximal end  43 , e.g., by unthreading the retainer distal end  220  from the implant threaded bore  70  (see  FIG. 20 ). The incision through which the delivery tool distal end  35  entered the patient can then be closed. 
     The anchor members  30  prevent migration of the implant  25  within the joint space. The anchor members  30  also can draw the ilium and sacrum together about the implant  25 , increasing the sturdiness of the fixation of the implant in the joint space. The anchor members extending through the implant bores and into the bone of both the sacrum and ilium allow the anchor members  30  to be used to drawn the articular surfaces  1016  of the sacroiliac joint  1000  against the external surfaces of the sacroiliac joint implant  25 . With the implant implanted in the sacroiliac joint, the body will cause the joint surfaces to fuse together about the implant  25 . 
     As shown in  FIG. 42N , another embodiment of the delivery tool  20  may include an implant arm  21  and an anchor arm  23  adapted to guide the delivery of an anchor  27  into the sacrum  1004 , ilium  1005 , or both the sacrum  1004  and ilium  1005  in transverse relation to the sacroiliac joint and the implant  25 . The implant arm  21  may include a distal region and a proximal region and may releasably couple with or be fixedly attached to the delivery tool  20 . The anchor arm  23  may extend from and be supported off of the implant arm  21 . The anchor arm  23  may include an extension member  29  and an anchor guide  31 , which may be a sleeve, collar, or other guide mechanism configured to guide an anchor  27  or anchor delivery tool (not shown) coupled with an anchor  27  along a trajectory  33  that is transverse (i.e., across) to a longitudinal axis of the implant  25 . As seen in the figure, the anchor arm  23  may be fixed and non-adjustable relative to the implant arm  21  and the delivery tool  20  such that the anchor  27  will be delivered in a pre-determined angular orientation relative to the implant  25  when the implant  25  is coupled with the distal end of the delivery tool  20  and when the anchor  27  is guided along the trajectory  33  via the anchor arm  23 . 
     As can be understood from  FIGS. 49A and 49B , which are, respectively, posterior and posterior-lateral views the implantation area and the implant assembly implanted there, proximal end  43  of the implant  25  can be seen positioned in the posterior inferior access region  2016 , the implant being implanted in the caudal area of the sacroiliac joint space. The anchor member  30  can be understood to have been driven into the implant bore  40  transversely to the joint plane  1030  via a route in the ilium  1005  that avoids contact with vascular and neurological structures, thereby avoiding potentially life threatening injury to such structures. The ability to blindly, yet safely, drive the anchor members  30  into the respective implant bores  40  and adjacent bones while the implant  25  is hidden in the joint space is made possible by the cooperating configurations of the implant  25  and the delivery tool  20 . Specifically, the guide lumens  132  of the delivery tool distal end  35  being axially aligned with the respective implant bores  40  when the proximal end  43  of the implant  25  is supported off of the distal end  35  of the delivery tool  20  makes it possible to safely drive the anchor members  30  through the implant bores  40  and into the ilium  1005  and sacrum  1004  when the implant is hidden in the joint space on account of being delivered to the joint space via the delivery tool  20 . 
     While the delivery tool  20  may be employed to deliver the implant  25  to the caudal portion  1086  of the sacroiliac joint space via the caudal approach discussed above with respect to  FIGS. 42A-49B , in other embodiments the other approaches and implant locations may be employed. For example, the implant  25  may be implanted in cranial portion  1087  of the sacroiliac joint space via a cranial approach as discussed in U.S. patent application Ser. No. 13/475,695 (“the &#39;695 application”), which is incorporated herein by reference in its entirety. Alternatively, as described in the &#39;695 application, the implant  25  may be implanted in the extra-articular space, as opposed to the sacroiliac joint articular region  1044 , the extra-articular space being accessed via the extra-articular recess access region. 
     In some embodiments, the system  10  may be provided in the form of a kit  4999 . Such a kit  4999  is shown in  FIG. 50 . The kit  4999  may include the system  10  enclosed in a sterile main package  5000 . For example, the delivery tool  20 , the implant  25  and anchor members  30  may be sealed within the sterile main package  5000 . The delivery tool  20  may be any of the tool embodiments disclosed herein and may include all of its components. Also, the implant  25  may be any of the implant embodiments disclosed herein. 
     As illustrated in  FIG. 113 , in some embodiments, the kit  4999  may include multiple sizes of the implant  25  and/or multiple sizes of the anchor members  30 . The multiple implants  25  may be contained in a sterile individual package  5002  within the sterile main package  5000 , and the multiple anchor members  30  may be contained in another sterile individual package  5004  within the sterile main package  5000 . By providing the multiple sizes of implants  25  and anchor members  30 , the implants and anchor members can be used as trials during certain steps of the procedure to determine appropriate implant sizes and to allow a physician, who is presented with the kit  4999  containing the delivery system  20  and multiple sizes and configurations of the implant and anchor members, to evaluate particular embodiments of an implant and anchor member as described herein that would be best suited to a particular patient, application or implant receiving space. The kit  4999  may also or alternatively contain multiple implants  25  with different angles of bores  40  to provide various desirable trajectories for anchor members  30  and multiple delivery systems  20  with as-manufactured angular relations corresponding to the different angles of the bores. The kit  4999  may also include color coded, numeric or other indicators corresponding between delivery systems  20  and the corresponding implants  25 . 
     In some embodiments, the kit  4999  may include instructions  5006  that lay out the steps of using the system  10 . The instructions  5006  may be contained within one of the sterile packages such as, for example, the sterile main package  5000 . Alternatively, the instructions  5006  may be adhered or otherwise attached to an exterior surface of one of the sterile packages such as, for example, the sterile main package  5000 . Alternatively, the instructions  5006  may be simply provided separately such as, for example, via simply shipped loose with the rest of the kit  4999 , emailed, available for download at a manufacturer website, or provided via a manufacture offered training seminar program. 
     In some embodiments, the kit  4999  may have any one or more of the tool  20 , implants  25  and anchor members  30  contained in individual sterile packages that are not held within a sterile main package. Alternatively, the tool  20 , implants  25  and anchor members  30  may be contained in a single common package or in any combination of packages and combination of tool, implants and anchor members. 
     As can be understood from  FIG. 51 , which is the same transverse cross sectional view of the patient&#39;s hip as shown in  FIG. 42M , once the implant  25  and anchors  30  are secured at the sacroiliac joint  1000  in the manner depicted in  FIG. 42M , the implant  25  can be used as an attachment point for structural components of a spinal support system configured to support across the patient&#39;s hip structure and/or to support along the patient&#39;s spinal column. To serve as an attachment point for structural components of a spinal support system, a coupling element  2087  is connected to the proximal end  2011  of the sacroiliac joint implant  25 . As a non-limiting example, the coupling element  2087  can be disposed in fixed relation to the proximal end  2011  of the sacroiliac joint implant  25  by threaded engagement of a fastener portion  2088 ; however, the invention is not so limited and the fastener portion  2088  can be connected to the first end  2011  of the sacroiliac joint implant  25  by any method such as welding, spin welding, adhesive, or the like. The coupling element  2087  can further provide a coupling portion  2089  configured to join with a numerous and wide variety of cross sectional geometries of spanning members  2090 . As a non-limiting example, the coupling portion  2089  can be configured as cylindrical cup  2091  pivotally coupled to the fastener portion  2088 . A spiral thread can be coupled to the internal surface of the cylindrical cup  2091  to rotationally receive a spirally threaded body  2092 . The side wall  2093  of the cylindrical cup  2091  can include a pass through element  2094  in which part of a spanning member  2090  can be received. The part of the spanning member  2090  received within the pass through element  2094  can be placed in fixed relation to the cylindrical cup  2091  by rotational engagement of the spirally threaded body  2092 . 
       FIG. 52  is a posterior view of the patient&#39;s sacrum  1004  and iliums  1005 , wherein structural components of a spinal support system extend medial-lateral across the patient&#39;s hip structure and superiorly to support along the patient&#39;s spinal column. As shown in  FIG. 52 , in one embodiment, each of a pair of sacroiliac joints  1000  can receive an embodiment of the sacroiliac joint implants  25 , disclosed herein, each having a coupling element  2087  coupled to the first end  2011 . Each of the coupling elements  2087  can receive the opposed ends  2095  of a spanning member  2090 . Additionally, the spanning member  2090  in fixed relation to the sacroiliac joint implants  25  can be connected to a plurality of additional spanning members  2096  which can as a non-limiting example be placed in positional relation to the vertebral column  2097  to allow support of additional implants which can be anchored between vertebrae. 
       FIG. 53  is the same view as  FIG. 52 , except having a different spanning member structure. As illustrated in  FIG. 53 , a first coupling element  2087  can be joined to the first end  2011  of an embodiment of a sacroiliac joint implant  25  as disclose herein and the fastener portion  2088  of a second coupling element  2087  can be disposed directly into the bone of the sacrum  1004  or the ilium  1005 , or both. The opposed ends  2095  of a spanning element  2090  in the form of a flat plate can provide apertures  2096  through which the fastener portion  2088  of the coupling element  2087  can pass. The corresponding parts of the external surface of the coupling portion  2089  and the spanning member  2090  can be engaged to fix the location of the spanning member  2090  allowing for coupling of the lumbar spine to the stabilized pelvis by a plurality of fixation elements to further increase stability. As an example, fastener  2088  can be a pedicle screw and may be implanted in the S1 pedicle and angled generally anteriorly and generally parallel to the S1 endplate. Alternatively or additionally, fastener  2088  can be a S2AI screw and may be implanted in the sacrum, across the sacroiliac joint, and terminate in or through the ilium. 
     In one embodiment, the implant  25  and spanning element  2090  of  FIG. 52  are a multi-piece arrangement as illustrated in  FIG. 52  and assembled during the surgery. In another embodiment, the implant  25  and spanning element  2090  of  FIG. 52  are in the form of an integral, unitary construction that is provided to the physician by a manufacturer in such an integral, unitary construction with the spanning element  2090  simply being an extension of a proximal region of the implant  25 . 
     Similarly, in one embodiment, the implant  25  and spanning element  2090  of  FIG. 53  are a multi-piece arrangement as illustrated in  FIG. 53  and assembled during the surgery. In another embodiment, the implant  25  and spanning element  2090  of  FIG. 53  are in the form of an integral, unitary construction that is provided to the physician by a manufacturer in such an integral, unitary construction with the spanning element  2090  simply being an extension of a proximal region of the implant  25 . 
     In one embodiment, as schematically depicted in  FIG. 54 , the implant  25  may be configured to include a stimulating electrode (NM) connected to an internal controllable power source or external controllable power source. For example, the external controllable power sources may be either in the delivery system instrumentation  20  itself or a separate controller unit located in the operating suite and electrically coupled to the implant supported electrode NM via electrical conductors extending through the implant body and the shaft  100  of the delivery system  20  to electrically couple to the separate controller unit via a cable extending proximally from the delivery system  20  to the separate controller. With the exception of the electrode (NM) itself, the entirety of the rest of the implant surfaces may be electrically insulated so as to prevent current shunting into surrounding tissues or the operator. 
     In one embodiment, the stimulating electrode (NM) during navigation can have an amperage of about 8 milliamps (mA) or, nearing final placement, an amperage of about 1-4 mA and, in certain cases, up to 5 mA. The electrode (NM) may be attached to or at least partially imbedded in implant  25  (either permanently or retrievable/removable after implantation) (or according to particular embodiments, located within, near or on the anchor  30 , probe  1054 , on or within a trial, broach, drill or other tools of system  10 ) to reduce the risk to the patient of iatrogenic damage to the nervous system by using intraoperative neurophysiological monitoring, for example electromyography (EMG), which is able to alert the surgeon or technician reliably and in real-time of implant  25  advancing beyond, for example, inferior boundary segment  3002  or beyond anterior-inferior corner  3010 . 
     As illustrated in  FIG. 54 , which is a schematic depiction of a joint implantation system  10  configured for nerve stimulating and sensing, in one embodiment, the system  10  includes a joint implant  25 , a delivery tool  20 , a nerve stimulating system  10003 , a pre-amplifier unit  10004 , an amplifier unit  10005 , a computer  10006 , and an electrical conductor pathway  10001 . The joint implant  25  includes an electrode NM and a body  45  including a distal end  42  and a proximal end  43  opposite the distal end. The electrode NM is supported on the implant  25 . The delivery tool  20  includes an implant arm  110  with a distal end  35  configured to releasably couple to the proximal end  43  of the body  45  of the joint implant  25 . The nerve stimulating system  10003  is configured to stimulate electrode NM in order to sense nerve contact made with the electrode NM or when NM is approaching and near a nerve. The electrical conductor pathway  10001  extends from the electrode NM along the implant  25  and implant arm  110  to the nerve stimulating system  10003 . The electrical conductor pathway  10001  places the electrode NM and nerve stimulating system  10003  in electrical communication. 
     A sensing (or recording) electrode  10011  can be placed in, for example, a quadriceps femoris, tibialis anterior, gastrocnemius, or abductor hallucis muscle and may be coupled to an electrical conductor pathway  10007  that extends to the pre-amplifier  10004 . A reference electrode  10010  can also be placed in, for example, a quadriceps femoris, tibialis anterior, gastrocnemius, or abductor hallucis muscle, but in a location between the area subject to stimulation from the stimulating electrode (NM) and the sensing (or recording) electrode  10011 ; and may be coupled to an electrical conductor pathway  10012  that extends to the nerve stimulating system  10003 . An additional needle  10009  can be placed in proximity to the aforementioned needles (i.e., electrodes  10010 ,  10011 ) within a muscle (or when the electrode is in the form of a patch it may be applied to the skin of the patient) and may be coupled to an electrical conductor pathway  10008  that extends to the pre-amplifier  10004  and a ground. 
     The pre-amplifier  10004  may be connected to the amplifier  10005  that itself may be connected to the computer unit  10006 . The computer unit  10006  may process or interpret the signal from the amplifier  10005  and display or otherwise alert (e.g., auditory signals with varying amplitude or frequency) or convey to an observer or operator in an operating suite or to a monitoring physician in a remote location (e.g., by employing computer software and processing and networking hardware) the state of the various electrical connections and pathways (e.g., connected versus disconnected) and electrical activity caused by the stimulating electrode NM. 
     In one embodiment, the proximal end  43  of the implant  25  and the distal end  35  of the implant arm include a cooperatively mating electrical connection  10000  that form a segment of the electrical conductor pathway  10001 . An example of such a cooperatively mating electrical connection includes a male-female pin contact assembly  10000 . The proximal end  80  of the delivery tool  20  and a distal end of an electrical conductor segment of the pathway  10001  between the sensing system  10003  and the proximal end  80  include a cooperatively mating electrical connection  10002  that form a segment of the electrical conductor pathway  10001 . The electrical conductor pathway  10001  may be in the form of one or more multi-filar cables, one or more solid core wires, etc. The electrode NM is at or near the distal end  42  of the implant  25  and the rest of the implant (or only an area directly surrounding the electrode NM) has an electrically insulative coating or is formed of an electrically nonconductive material. 
     To begin a detailed discussion of a second embodiment of the system  10 , reference is made to  FIGS. 55A-56 .  FIG. 55A  is an isometric view of the system  10 .  FIG. 55B  is the same view as  FIG. 55A , except an implant assembly  15  of the system  10  is separated from a delivery tool  20  of the system  10 .  FIG. 56  is the same view as  FIG. 55A , except the system  10  is shown exploded to better illustrate the components of the system  10 . 
     As can be understood from  FIGS. 55A and 55B , the system  10  includes a delivery tool  20  and an implant assembly  15  for implanting at the sacroiliac joint via the delivery tool  20 , the implant assembly  15  being for fusing the sacroiliac joint. As indicated in  FIG. 56 , the implant assembly  15  includes an implant  25  and anchor elements  30  (e.g., self-locking blades or other elongated bodies slidably extendable from the implant body). As discussed below in greater detail, during the implantation of the implant assembly  15  at the sacroiliac joint, the implant  25  and anchor element  30  are supported by a distal end  35  of the delivery tool  20 , as illustrated in  FIG. 55A . In one embodiment, the distal end  35  may be fixed or non-removable from the rest of the delivery tool  20 . In other embodiments, the distal end  35  of the delivery tool  20  may be removable so as to allow interchanging of different sized or shaped distal ends  35  to allow matching to particular implant embodiments without requiring the use of a different delivery tool  20 . The delivery tool  20  is used to deliver the implant  25  into the sacroiliac joint space. The delivery tool  20  is then used to cause the anchor elements  30  to deploy or otherwise extend from the sides of the implant  25  and into the bone of the ilium and sacrum defining the sacroiliac joint. The delivery tool  20  is then decoupled from the implanted implant assembly  15 , as can be understood from  FIG. 55B . 
     To begin a detailed discussion of components of an embodiment of the implant assembly  15 , reference is made to  FIGS. 57A-57F , which are various isometric, end elevation, side elevation, and plan views of the implant assembly  15 . As shown in  FIGS. 57A-57F , the implant assembly  15  includes an implant  25  and anchor elements  30 . In one embodiment, the anchor elements  30  may be in the form of an self-locking blades  30  or other elongated bodies slidably extendable from the implant body. 
     As indicated in  FIGS. 57A-57F , the anchor elements  30  are configured to be received in bores  40  defined through the implant  25 . The bores  40  extend through the implant  25  distally and laterally from a proximal end  43  of the implant  25  and are sized such that the anchor elements  30  can at least project both laterally and distally from the sides of the implant  25  as illustrated in  FIGS. 57A-57F . In one embodiment, the anchor elements  30  may be generally blade-like members  30  that are substantially wider and longer than thick. Where the anchor elements  30  are blade-like, the bores  40  may then be slots  40  that are shaped to match the blade-like anchor elements  30  received therein. Each blade-like member  30  may have a slight curvature along its length that matches the slight curvature of the slot  40  in which the blade-like member  30  is received, as can be understood from  FIG. 61 , which is a longitudinal cross section of the implant  25  as taken along section line  61 - 61  in  FIG. 60 . 
     As can be understood from  FIGS. 57A-57F , the blade-like anchor members  30  may have a distal or leading edge  30 A with a notch  30 B defined therein. Serrations or other anti-migration features  30 C may be defined in the side edges  30 D of the members  30 . Locking tabs  30 E may extend from the side edges  30 D of each member  30  to bias outwardly once free of the confines of the slot  40  after the member  30  has been sufficiently distally displaced out of the slot  40 . By biasing outwardly to have an overall width that is greater than the width of the corresponding slot  40 , the locking tabs  30 E prevent the proximal migration of the member  30  within the slot  40 . By applying a distal acting force on the blunt proximal end  30 F of a member  30 , the member  30  may be caused to slide distally within its slot  40  to cause the distal end  30 A of the member  30  to project distally and laterally from the implant body  45 , such projection being capable of anchoring the implant assembly  15  into bone defining the sacroiliac joint space. 
     For a detailed discussion of the implant  25  of the implant assembly  15  discussed above with respect to  FIGS. 57A-57F , reference is made to  FIGS. 58-61 .  FIG. 58  is an isometric view of the implant  25 .  FIGS. 59 and 60  are, respectively, plan and proximal end elevation views of the implant  25 .  FIG. 61  is an isometric longitudinal cross section of the implant  25  as taken along section lines  61 - 61  in  FIG. 60 . 
     As shown in  FIGS. 58-61 , in one embodiment, the implant  25  includes a distal or leading end  42 , a proximal or trailing end  43 , a longitudinally extending body  45 , slots  40  extending distally and laterally through the body from the proximal end  43 , an attachment bore  70 , and an opening  50 . In one embodiment, as reflected in  FIGS. 58-61 , the implant body  45  has a generally rectangular box shape. However, in other embodiments similar to that discussed above with respect to  FIGS. 5-15 , the implant body  45  may be configured to have a shape that generally mimics and even substantially fills a sacroiliac joint space. 
     As illustrated in  FIG. 60 , the implant  25  includes a proximal end  43  for being removably coupled to the extreme distal end  35  of the delivery tool  20 . Specifically, in one embodiment, the implant proximal end  43  includes an attachment bore  70  that extends distally through the implant from the proximal end  43 . The attachment bore  70  may be a blind hole in that it only has a single opening, which is at the proximal end  43 . Alternatively, the attachment bore  70  may be configured as a hole that communicates between the implant proximal end  43  and implant opening  50 . The attachment bore  70  may be threaded or otherwise configured so as to allow mechanical engagement with a distal end  220  of a retainer member  95  of the delivery tool  20 , the retainer member  95  being used to secure the implant  25  off of the distal end  35  of the delivery tool  20 , as described in detail below. In one embodiment, the attachment bore  70  has a diameter of between approximately 2 mm and approximately 10 mm, with one embodiment having a diameter of approximately 5 mm. 
     In one embodiment, the implant  25  can be configured such that the body  45  of the implant is a generally continuous solid surface with the exception of the slots  40  and bore  70  extending through portions of the body  45 . However, as illustrated in  FIGS. 58 and 60 , in other embodiments, the body  45  of the implant  25  may have one or more openings or voids defined in the body  45 . For example, an opening or void  50  may be defined in the implant body  45 . The void  50  may be packed with bone growth material prior to the implant  25  being delivered into the sacroiliac joint space. 
     As indicated in  FIGS. 58-60 , the implant body  45  includes side edge surfaces  7150  that extend between the proximal end  43  and the distal end  42 . These side edge surfaces  7150  and the similar side edge surfaces associated with the distal end  42  and proximal end  43  combine to define side edge surface boundary that extends unbroken and unitary through all of the above-mentioned regions of the implant, thereby forming an outer boundary that may at least somewhat resemble a rectangle. In other embodiments, the outer boundary formed by the side edge surfaces may resemble other shapes including, for example, a circle, an oval or etc. In one embodiment, the outer boundary formed by the side edge surfaces may even resemble the sacroiliac joint space as discussed above with respect to  FIGS. 5-15 , thereby allowing the implant  25  to more fully occupy the joint space than more linearly shaped rectangle and cylindrical implant embodiments. 
     As illustrated in  FIGS. 58-61 , in one embodiment, the implant body  45  includes generally planar lateral side surfaces  7060 . In some embodiments, the lateral side surfaces  7060  may be generally spaced apart by a distance or body thickness that is generally continuous over the entirety of the surfaces  7060 . However, in some embodiments, the distance or body thickness may taper from a greater thickness in some regions of the body to a lesser thickness in other regions of the body. 
     In one embodiment, the planar lateral side surfaces  7060  may be substantially smooth. However, in other embodiments, as indicated in  FIGS. 58-61 , the planar lateral side surfaces  7060  may have multiple parallel ridges  7061  that extend longitudinally along the long portion  7100  and may be serrated with notches  7062  oriented so as to prevent proximal migration of the implant  25  once implanted in the sacroiliac joint. The anti-migration features  7062  are generally evenly distributed along the planar surfaces  7060 . While the anti-migration features  7062  are depicted as being notches  7062  defined in the longitudinally extending ribs or ridges  7061 , in other embodiments the anti-migration features  7062  may be in the form of other types of surface texturing or protrusions in the form of cylinders, trapezoids, squares, rectangles, etc. Further, although the anti-migration features  7062  are depicted in the form of unidirectional serrated notches  7062  in ridges  7061  on the planar lateral side surfaces  7060  the implant  25 , the invention is not so limited and, as to particular embodiments, can be configured to have said features  7062  arranged in multiple directions, unidirectional, or a combination of multiple direction on some surfaces of the implant and unidirectional on other surfaces of the implant. Accordingly, the features  7062  can be so arranged on the various surfaces of the implant so as to prevent undesired migration in particular directions due to the forces present at the sacroiliac joint  1000 . 
     As indicated in  FIGS. 58 and 60 , a longitudinally extending rectangular notch  6514  may be defined in a side edge surface  7150 . As described below, such a notch  6514  may interact with a member  140  forming part of the delivery tool distal end  35  so as to help retain the implant  25  on the distal end  35  and to prevent the implant from rotating relative to the distal end  35  when the retaining rod threaded distal end  220  is being threaded into or out of the attachment bore  70 . 
     As can be understood from  FIGS. 58-61 , in one embodiment, the slots  40  extend distally and laterally from a proximal end  43  of the implant  25  to daylight distally in the planar lateral side surfaces  7060 , thereby exiting the implant body  45  laterally as slots  40  defined in the planar lateral side surface  7060 . Since the slots  40  are oriented so as to extend distally and laterally from the proximal end  43  and, further, since the blade-like anchors  30  have sufficient length, the anchors  30  project both laterally and distally from the planar lateral side surfaces  7060  of the implant  25 , as illustrated in  FIGS. 57A-57F . 
     In one embodiment, the implant  25  may be machined, molded, formed, or otherwise manufactured from stainless steel, titanium, ceramic, polymer, composite, bone or other biocompatible materials. The anchor member  30  may be machined, molded, formed or otherwise manufactured from similar biocompatible materials. 
     As to particular embodiments as shown in  FIGS. 57A-61 , and in other embodiments as disclosed throughout, the implants described herein can be configured to be used as trials during certain steps of the procedure to determine appropriate implant sizes and to allow a physician, who is presented with a kit containing the delivery system  20  and multiple sizes and configurations of the implant  15 , to evaluate particular embodiments of an implant as described herein that would be best suited to a particular patient, application or implant receiving space. 
     The particular embodiments of  FIGS. 57A-61  depict implant assemblies  15  having an implant  25  with a generally planar body  45  such that the width and length of the body  45  are substantially greater than the thickness of the body  45  and the planar body  45  is generally free of any substantial features of the body extending away from the planar lateral side surfaces  7060 . However, in other embodiments, the implant body  45  of the present disclosure may have the anchoring arrangement illustrated in  FIGS. 57A-61  and further be configured to have a shape and/or radially extending wings as described with respect to any of the many implant body embodiments described in U.S. patent application Ser. No. 13/475,695, which was filed May 18, 2012 and is hereby incorporated by reference in its entirety. 
     To begin a detailed discussion of components of an embodiment of the delivery tool  20 , reference is again made to  FIGS. 55A-56 . As shown in  FIG. 55A , the delivery tool  20  includes a distal end  35  and a proximal end  80 . The distal end  35  supports the components  25 ,  30  of the implant assembly  15 , and the proximal end  80  is configured to be grasped and manipulated to facilitate the implantation of the implant assembly  15  in the sacroiliac joint. 
     As illustrated in  FIG. 56 , the delivery tool  20  further includes a shaft assembly  85 , a handle  90 , an implant retainer  95 , and an impactor  97 . As shown in  FIGS. 62A and 62B , which are, respectively, distal and proximal isometric views of the shaft assembly  85 , the shaft assembly  85  includes the handle  90 , a tubular elongated body  100 , a distal implant engagement end  105 , and an impactor guide  161 . The handle  90  is coupled on a proximal end  110  of the tubular elongated body  100 . The tubular elongated body  100  includes a lumen  115  through which the implant retainer  95  extends, as described below. The impactor guide  161  is a rectangular opening longitudinally extending through a guide head  162  of the distal implant engagement end  105 . 
     As illustrated in  FIG. 63 , which is a distal isometric view of the implant retainer  95 , the implant retainer  95  includes a longitudinal cylindrical member  210 , a handle  215  on a proximal end of the longitudinal cylindrical member  210 , and an implant engagement feature  220  on a distal end the longitudinal cylindrical member  210 . As can be understood from  FIG. 65 , which is a distal isometric view of the delivery tool  20 , the member  210  of the implant retainer  95  extends through the lumen  115  of the body  100 , the engagement feature  220  distally extending from the lumen  115  when a distal face of the retainer handle  215  is abutting against a proximal face of the shaft assembly handle  90 . 
     As illustrated in  FIG. 64 , which is a distal isometric view of the impactor  97 , the impactor  97  includes a shaft  97 A, a handle  97 B on a proximal end of the shaft  97 A, and an impactor head  97 C on a distal end of the shaft  97 A. The impactor head  97 C includes planar lateral sides that taper slightly as the planar lateral sides extend distally to a blunt distal end  97 D of the impactor head  97 C. As can be understood from  FIGS. 62A-62B , the impactor guide  161  is in the form of a tapered rectangular hole  161  that generally matches the shape of the impactor head  97 C. Thus, the impactor guide hole  161  includes planar lateral sides that taper slightly as the planar lateral sides extend distally to the distal daylight opening of the hole  161  in the guide head  162 . As can be understood from  FIG. 65 , the interaction of the tapered configurations of the impactor head  97 C and the impactor guide hole  161  allow the impactor head  97 C to displace distal-proximal within impactor guide hole  161 , but limits the maximum distal displacement of the impactor head  97 C within the impactor guide hole  161  such that the blunt distal end  97 D can protrude from the distal end of the guide head  162  only a small distance. 
     As shown in  FIG. 62A , the distal implant engagement end  105  includes a distal face  130  that surrounds the distal opening of the anchor guide hole  161  and from which a distally extending member  140  distally projects. The member  140  has a planar face  142  that is configured to be matingly received by the notch  6514  of the implant  25  when the proximal end  43  of the implant  25  is received in an implant receiving space  143  (shown in  FIG. 56 ) defined by the distal face  130  and planar face  142  (shown in  FIG. 62A ). The implant  25  so coupled to the distal implant engagement end  105  of the delivery tool  20  is illustrated in  FIG. 67 , which is an enlarged distal isometric view of the system  10 . 
     As can be understood from  FIG. 66 , which is an isometric view of the implant assembly  15  coupled to the implant retainer  95 , the impactor  97  positioned as having fully distally driven the anchors  30 , and the rest of the delivery tool  20  hidden for clarity purposes, in one embodiment, the implant engagement feature  220  is in the form of a threaded shaft for engaging complementary threads in the attachment bore  70 , thereby securing the implant proximal face  43  against the distal face  130  of the distal implant engagement end  105 , the member  140  being received in the notch  6514 , as can be understood from  FIGS. 55A and 67 . The blunt distal end  97 D of the impactor head  97 C is abutting against the implant proximal face  43  after having been displaced sufficiently distal so as to impact the blades proximal ends  30 F to drive the anchor blades  30  fully distal in their respective slots  40  such that the blade tabs  30 E have exited the distal openings of the respective slots  40  and biased wide to prevent the proximal migration of the anchor blades  30  within the slots  40 . 
     As illustrated in  FIG. 68 , which is a distal isometric view of the impactor  97  abutting against the proximal ends of the anchors  30 , the rest of the delivery tool and implant being hidden for clarity purposes, the blunt distal end  97 D can be brought into impacting contact with the proximal ends  30 F of the blade anchors  30 . As can be understood from  FIGS. 65-66 , the threaded distal end  220  of the retainer  95  is threadably received in the attachment bore  70  of the implant  25  to retain the implant  25  in the implant receiving area  143  (see  FIG. 56 ) of the tool attachment end  105 . Also, the impactor head  97 C is guided in its distal-proximal displacement against the anchor proximal ends  30 F by the guide head hole  161 . 
     Prior to being distally driven through the slots  40  by the impactor  97 , the implant  25  may be secured to the distal end of the tool  10  via the mechanical interaction of the retainer distal end  220  in the implant attachment hole  70 . The blades  30  may be staged in the slots  40  by inserting just the blade distal ends  30 A in the proximal openings of the slots  40  when the implant is supported off of the distal end of the delivery tool  10 . With the blades so positioned and the implant so supported, the implant can be delivered into the sacroiliac joint via the delivery tool, and once the implant is positioned within the sacroiliac joint as desired, the impactor  97  can then be used to drive the blades  30  from being substantially in the guide hole  161  and only partially in the slots  40  to being fully out of the guide hole  161  and into the implant slots  40  such that the distal ends  30 A of the blades  30  distally and laterally project from the lateral faces of  7060  of the implant  25  a substantial distance. 
     It should be noted that the delivery methods described above with respect to  FIGS. 25-53  are readily adaptable to the implant system  15  and delivery tool  20  discussed with respect to  FIGS. 55A-68 , the main difference being that the anchor blades  30  of the implant  25  of  FIGS. 57A-57F  are impacted through the implant  25  and into the adjacent sacrum and ilium bone, as opposed to being screwed through the implant  25  and into the adjacent bone as is the case with the screw anchors  30  of the implant  25  of  FIGS. 4A-4C . 
     The systems  10  disclosed herein may be further configured, as disclosed in U.S. patent application Ser. No. 13/475,695, which was filed May 18, 2012 and is incorporated herein in its entirety, to allow placement of an anchor  30  near the implant or through a part of the implant  25  from a generally medial or, in some embodiments, a lateral approach as guided by the delivery tool. 
     To begin a detailed discussion of another method of accessing a sacroiliac joint space to treat a musculoskeletal condition, reference is made to  FIGS. 69-71 . To begin and as can be understood from  FIGS. 69 and 70 , a stab incision is made in the patient&#39;s skin to create an entry point near the coccyx and the sacrotuberous ligament. A cannulated blunt dissecting tool for deflecting soft tissue away from the sacrum may be advanced through the entry point and advanced while following the sacrum up to a sacroiliac joint inferior boundary  3002  which is immediately adjacent, and extends along, the sciatic notch  2024 . A guide wire may then be placed through the cannulation in the dissecting tool and advanced into the sacroiliac joint. Optionally, after the dissecting tool has been removed an inflatable bowel retractor may be advanced over the guide wire and, once in place, inflated to provide a protected passageway for access to a sacroiliac joint. A working cannula may then be advanced over the guide wire to further protect the soft tissues from subsequent use of tools during the remainder of the procedure. The guide wire may then be removed or alternatively left in place to be used to guide an implant delivery tool up to the sacroiliac joint. Regardless, as can be understood from  FIG. 71 , any of the tools  20  disclosed herein can be used along the surgical pathway depicted in  FIGS. 69 and 70  to deliver corresponding implants  15  into the sacroiliac joint space. 
     To begin a discussion regarding an embodiment of an implant  15  including an integral rotating anchor arrangement, reference is made to  FIGS. 72-76 , which are various isometric, side, and end views of such an implant  15 . As shown in  FIGS. 72-76 , the implant  25  includes a distal or leading end  42 , a proximal or trailing end  43 , a longitudinally extending body  45 , bores  70  for coupling the implant to a delivery tool, a center opening  50 , and an anchor  30  pivotably supported in the center opening  50 . In one embodiment, the implant  25  is configured to have a shape that generally mimics and even substantially fills a sacroiliac joint space. However, as indicated in  FIGS. 72-76 , in one embodiment, the implant  50  is generally rectangular in shape and includes large opposed radial members  7149  terminating in edge faces  7150  and small opposed radial members terminating  7153  in edge faces  7151 , the small opposed radial members  7153  being generally perpendicular to the large opposed radial members  7149 . 
     As illustrated in  FIG. 76 , the implant  25  includes a proximal end  43  for being removably coupled to the extreme distal end  35  of the delivery tool  20 . Specifically, in one embodiment, the implant proximal end  43  includes a bores  70  that extends distally into the implant from the proximal end  43 . The bores  70  may be blind holes in that they each only have a single opening, which is at the proximal end  43 . Alternatively, the bores  70  may be configured as holes that communicate between the implant proximal end  43  and implant center opening  50 . The bores  70  may be threaded or otherwise configured so as to allow mechanical engagement with a distal end of a retainer feature of the delivery tool  20 , the retainer feature being used to secure the implant  25  off of the distal end  35  of the delivery tool  20 , as described in detail below. 
     As indicated in  FIGS. 72-76 , the implant body  45  includes side edge surfaces  7150  of the large radial members and side edge surfaces  7151  of the small radial members that extend between the proximal end  43  and the distal end  42 . The center opening  50  is defined in the body  45  so as to extend through an inner region of the large radial members  7149  and through the entirety of the small radial members  7153  such that side edge surfaces  7151  of the small radial members  7153  are not continuous distal to proximal but instead from a distal region and a proximal region separated by center opening  50 . 
     As illustrated in  FIGS. 72-76 , in one embodiment, the implant body  45  includes generally planar lateral side surfaces  7060  of the large radial members  7149 . In some embodiments, the lateral side surfaces  7060  may be generally spaced apart by a distance or body thickness that is generally continuous over the entirety of the surfaces  7060 . However, as can be understood from  FIGS. 13 and 14 , in some embodiments, the distance or body thickness may vary along the length of the implant body  45   
     In one embodiment, the planar lateral side surfaces  7060  may be substantially smooth. However, in other embodiments, as indicated in  FIGS. 72-76 , the planar lateral side surfaces  7060  may have multiple serrated features  7061  configurations and spacing  7062  oriented so as to prevent proximal migration of the implant  25  once implanted in the sacroiliac joint. The anti-migration features  7061  are generally evenly distributed along the planar surfaces  7060 . Anti-migration features may also be defined in the outer surface faces  7151  of the small radial members  7153  in the form of notches  7063 . While the anti-migration features are depicted as being serrated features  7061  or notches  7063 , in other embodiments the anti-migration features may be in the form of other types of surface texturing or protrusions in the form of cylinders, trapezoids, squares, rectangles, etc. Further, although the anti-migration features are depicted in the form of unidirectional serrated features or notches on large and small radial members of the implant  25 , the invention is not so limited and, as to particular embodiments, can be configured to have of the anti-migration features arranged in multiple directions, unidirectional, or a combination of multiple direction on some surfaces of the implant and unidirectional on other surfaces of the implant. Accordingly, the anti-migration features can be so arranged on the various surfaces of the implant so as to prevent undesired migration in particular directions due to the forces present at the sacroiliac joint  1000 . 
     As can be understood from  FIGS. 72-76 , the anchor  30  includes bone engagement features  30 A radially extending from a center axle  30 B about which the anchor  30  is pivotally coupled to the implant body  45  so as to be capable of rotating or pivoting within the confines of the center opening  50 . The center axle  30 B is generally coaxially arranged with a longitudinal center axis of the implant body  45 , as can be understood from  FIG. 77 , which is an isometric view of another version of the implant having a rotating integral anchor. 
     As illustrated in  FIG. 77 , the proximal end  30 C of the anchor  30  may include an engagement feature (e.g., hex-head) for engagement by a complementarily shaped distal end  7111  of a tool (e.g. hex-head wrench or screwdriver) extending through the delivery tool  20  to cause the anchor  30  to rotate about its axle  30 B within the center opening  50  defined in the implant body  45  so as to bring the engagement features  30 A of the anchor  30  into anchoring engagement with the sacrum and ilium bordering the sacroiliac joint space. When the implant  15  is delivered into the sacroiliac joint space via the delivery tool, the anchor  30  is rotationally positioned in the opening  50  such that the engagement features  30 A are each in alignment with the small radial members  7153  or, alternatively, in alignment with the large radial members  7149 . Thus, the engagement features  30 A are protected from interaction with the bone of the sacrum or ilium by being so aligned with the one set of the radial members. Once the implant  15  is positioned as desired in the sacroiliac joint space, the anchor  30  can be caused to rotate about its axle  30 B so as to cause its engagement members  30 A to engage the sacrum and ilium in an anchoring fashion. The anchor  30  may have a locking mechanism such as, for example, a pawl tooth or ratchet arrangement, a setscrew, or etc., to prevent the anchor  30  from reverse rotating such that the engagement members  30 A ceasing to anchor within the bone of the sacrum and ilium. 
     As can be understood from a comparison of the anchors  30  of the embodiments of  FIGS. 72 and 77  and further as can be understood from the same respective anchors shown alone in  FIGS. 78 and 79 , the engagement features  30 A may vary. For example, as shown in  FIGS. 72 and 78 , in one embodiment, the engagement features  30 A may be in the form of longitudinally extending blades  30 A supported off of radially extending pairs of arms  30 D from the axle  30 B. In another embodiment, as depicted in  FIGS. 77 and 79 , the engagement features  30 A may be in the form of radially extending arms  30 D terminating in tapered points  30 E with an optional radially extending edge  30 F. 
     In one embodiment, as illustrated in  FIGS. 80-84 , which are various isometric, side and end views of another implant  15 , the implant  15  may be free of radially extending members and simply have a body  45  with the opening  50  and the anchor  30  pivotably supported therein. The rest of the feature of the implant  15  may be generally the same as already described, the implant body  15  having a generally rectangular shape with tapered distal end  42  and tapered proximal end  43 . As can be understood from  FIGS. 80-84 , the engagement feature  30 A of the anchor  30  may be in the form of a hook. Such an anchor embodiment may be employed with the implants of  FIGS. 72-79  or the anchors embodiments of those figures may be employed with the implant of  FIGS. 80-84 . 
     In one embodiment, the implants  25  of  FIGS. 72-84  may be machined, molded, formed, or otherwise manufactured from stainless steel, titanium, ceramic, polymer, composite, bone or other biocompatible materials. The anchor member  30  may be machined, molded, formed or otherwise manufactured from similar biocompatible materials. 
     In one embodiment, a delivery tool  20  for use with the implant embodiments of the  FIGS. 72-84  may be configured as illustrated in  FIG. 85 . Such a tool  20  may have an implant arm  110  formed mainly of a sleeve  110 Z and a retainer rod  110 X. The retainer rod  110 X may be received coaxially within the sleeve  110 Z. 
     The retainer rod  110 X includes a shaft  10030  that distally terminates in opposed arms  10032 , which in turn terminate in retainer arms or prong arms  140 . As shown in  FIG. 85 , when the rod  110 X is free of the sleeve  110 Z, the opposed arms  10032  are biased apart, resulting in a space-apart distance indicated by arrow D that is sufficiently wide to allow the implant  25  to be received between the prong arms  140  at the rod distal end  120 . 
     As indicated in  FIG. 85 , the sleeve  110 Z includes a distal end  10040 , a proximal end  10042 , and slots  10044  that extend into the hollow interior of the shaft of the sleeve  110 Z. The slots  10044  provide opening into the hollow interior to facilitate sterilization of the sleeve  110 Z via an autoclave. A knurled gripping surface  10046  is defined near the sleeve proximal end  10042  so as to facilitate rotation of the sleeve relative to the rod when the threads  110 Y are being threadably engaged. 
     As can be understood from a comparison of  FIG. 85 , when the sleeve  110 Z is advanced distally over the retainer rod  110 X, complementary threads  110 Y on both the sleeve  110 Z and retainer rod  110 X can be engaged and the sleeve can be rotatably driven distally by said thread engagement. Alternatively, a lever or other mechanical arrangement may be provided to cause the sleeve to be driven distally. The sleeve  110 Z advancing distally causes prong arms  140  of the retainer rod  110 X to draw toward one another and in turn cause the portion of the retainer rod which couples to the implant  25  to grasp the implant. The complementary threads when engaged may prevent proximal movement of the sleeve  110 Z relative to the rod  110 X and allow the coupling of implant and retainer rod to continue throughout the course of the procedure. While the tool  20  is coupled to the implant  15 , a hex-head wrench or screwdriver  7111  may be extended down a central lumen of the shaft  10030  to engage the hex-head end  30 C (see  FIG. 77 ) of the anchor  30  of the implant to cause its engagement features  30 A to rotate into anchoring engagement with the sacrum and ilium. After implantation the sleeve  110 Z may be caused to move proximally along the retainer rod  110 X in order to decouple the aforementioned tool and implant arrangement. 
     The foregoing merely illustrates the principles of the invention. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements and methods which, although not explicitly shown or described herein, embody the principles of the invention and are thus within the spirit and scope of the present invention. From the above description and drawings, it will be understood by those of ordinary skill in the art that the particular embodiments shown and described are for purposes of illustrations only and are not intended to limit the scope of the present invention. References to details of particular embodiments are not intended to limit the scope of the invention.