Systems and methods for the fusion of the sacral-iliac joint

#This application relates generally to the fixation or fusion of bone.

#Many types of hardware are available both for the fixation of bones that are fractured and for the fixation of bones that are to fused (arthrodesed).

#For example, the human hip girdle (see FIGS. 9 and 10) is made up of three large bones joined by three relatively immobile joints. One of the bones is called the sacrum and it lies at the bottom of the lumbar spine, where it connects with the L5 vertebra. The other two bones are commonly called “hip bones” and are technically referred to as the right ilium and the left ilium. The sacrum connects with both hip bones at the sacroiliac joint (in shorthand, the SI-Joint).

#FIG. 1 is a side section view of a compression stem assembly assembled in adjacent bone regions, which are shown in FIG. 1 in a diagrammatically fashion for the purpose of illustration, without anatomic detail, which is later shown, e.g., in FIG. 16.

#FIG. 2 is an exploded perspective view of the components of the compression stem assembly shown in FIG. 1 prior to assembly.

#FIGS. 3 to 7 are alternative embodiments of an implant structure which forms a part of the compression stem assembly shown in FIGS. 1 and 2, illustrating different cross-sectional geometries and configurations for the implant structure 20.

#Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention that may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.

#FIGS. 1 and 2 show in assembled and exploded views, respectively, a representative configuration of a compression stem assembly 10 sized and configured for the fixation of bone fractures (i.e., fixation of parts of the same bone) or for the fixation of bones which are to be fused (arthrodesed) (i.e. fixation of two or more individual bones that are adjacent and/or jointed). For the sake of shorthand, the assembly 10 will sometimes be called a bone fixation/fusion compression assembly, to indicate that it can perform a fixation function between two or more individual bones), or a fusion function between two or more parts of the same bone, or both functions. As used herein, “bone segments” or “adjacent bone regions” refer to either situation, i.e., a fracture line in a single bone or a space or joint between different bone segments. In FIG. 1, the bone segment or adjacent bone regions are shown diagrammatically without anatomic detail for the purpose of illustration. Later, e.g., in FIGS. 13 to 16 and FIGS. 20 to 22, the bone segments or adjacent bone regions are shown in a specific anatomic setting, comprising the joint between the sacrum and the ilium of the pelvis, also anatomically called the sacroiliac joint (SI-Joint).

#As shown in FIGS. 1 and 2, the compression stem assembly 10 comprises an anchor body 12, which (as shown in FIG. 1) is sized and configured to be placed in compression within bone segments or adjacent bone regions. In a representative embodiment, the anchor body 12 takes the form of a cylindrical anchor pin or rod. Still, the anchor body 12 can possess other geometries.