Sacroiliac joint implant system

A method of treating a sacroiliac joint at a sacroiliac joint region having a sacrum, an ilium and a sacroiliac joint space therebetween, the ilium comprising a posterior inferior iliac spine (PIIS) and a posterior superior iliac spine (PSIS), the method comprising:

• delivering a joint implant into the sacroiliac joint region via a posterior approach such that the joint implant passes through a posterior access region defined between the PSIS and the PIIS, the joint implant being oriented in the sacroiliac joint space such that a portion of the joint implant is positioned within a joint plane of the sacroiliac joint space, the joint implant comprising a body including a length extending between a proximal end and a distal end, an external surface extending the length, and a fixation member receiving channel extending the length and disposed in the external surface;
• and
• delivering a fixation member into the fixation member receiving channel thereby forming a joint implant assembly, the fixation member slidingly and matingly engaging the fixation member receiving channel in a grooved arrangement, wherein, when the fixation member is received into the fixation member receiving channel, the fixation member extends outward from the external surface of the joint implant and extends a portion of the length, wherein the fixation member comprises a channel insertion element configured to engage the fixation member receiving channel, a projection element coupled to the channel insertion element and comprising one or more aperture elements which communicate between opposite sides of the projection element, and a terminal element coupled to the projection element and oriented generally perpendicular thereto,
• wherein, when the joint implant is delivered into the sacroiliac joint region and when the fixation member is delivered into the fixation member receiving channel, the projection element is configured to extend from the external surface and into engagement with at least one of the sacrum or the ilium.