Anti-rotation mechanism for a sacroiliac screw

A sacroiliac screw comprising:

• a screw implant with a proximal end having an outer surface with an outer groove, and a distal end having external screw threads extending distally from the outer surface to a distal tip;
• a screw head cap having an inner surface with an inner groove and ratcheting geometric features configured to slide on the outer surface of the screw implant, and an outer surface with radial fins;
• a split washer configured to fit within the external groove and internal groove to rotatably couple the screw head cap with the screw implant;
• and
• a flexible pin having a first end fixedly coupled with the outer surface of the screw implant and a second end flexibly coupled with the ratcheting geometric features of the screw head cap;
• wherein with the ratcheting geometric features and flexible pin allow rotation of the screw head cap in a first direction and prevent rotation of the screw head cap in a second direction.

A sacroiliac screw comprising:

• a screw implant having external screw threads on a distal end and an external groove on a proximal end;
• a screw head cap having an inner surface configured to rotatably couple with the proximal end of the screw implant and an outer surface with radial fins, the inner surface having ratcheting geometric features and an internal groove;
• a split washer configured to fit within the external groove and internal groove to prevent the screw head cap from uncoupling with the screw implant;
• and
• a flexible pin having a first end fixedly couple with the screw implant and a second end flexible coupled with ratcheting geometric features to allow rotation of the screw head cap in a first direction and prevent rotation in a second, opposite direction.