Bone anchor with deployable purchase element

A bone anchor for connecting a rod to a bone structure, the bone anchor comprising a front, a back, opposing sides, a proximal end, and a distal end, the bone anchor further comprising:

• a rod housing configured to accommodate the rod;
• a hook member extending distally from the rod housing and curving forward, the hook member comprising a distal portion formed by two prongs with a groove therebetween;
• a cavity distal to the rod housing and dimensioned to accommodate the bone structure, the cavity bordered by the rod housing and the hook member;
• a purchase element housing positioned at the front of the bone anchor, wherein the purchase element housing is positioned above and in longitudinal alignment with the distal portion of the hook member;
• and
• a deployable purchase element movably received in the purchase element housing, the purchase element adapted to assume a retracted position in which the purchase element is retracted from the cavity, and adapted to assume a deployed position in which the purchase element is advanced into the cavity, wherein the purchase element comprises two purchase members, each purchase member comprising a distal tip, wherein each purchase member is adapted to be advanced toward and away from one of the prongs of the hook member.