The Orion SI Joint System consists of cannulated, fully threaded screws with double helix threads designed to be able to screw into pre-drilled bone. It is fabricated from medical grade titanium alloy, Ti-6Al-4V (ASTM F-136). The Orion SI Joint System implants come in various sizes and lengths to accommodate patient anatomy. Optional washers are included for each screw diameter to aid in conforming to patient anatomy. Orion SI Joint System features distal cutting flutes and dual lead threads which allow for effortless bone grip. Also perforated, it features an open implant design resulting in improved osseointegration and reduced radiographic signature. Integrated safety features help control targeting and screw insertion and incorporate a post fusion removal system. The Orion system includes numerous surgical instruments used to prepare the site to insert the implants safely and efficiently.