Bone anchor assembly and methods of use

A method of treating the spine of a patient, the method comprising:

• inserting two or more anchors into a plurality of adjacent vertebrae, each anchor having a head and a shaft;
• providing a housing for each anchor, each housing having a first passage extending longitudinally therethrough between an upper opening and a lower opening, a second passage transverse to the first passage and configured to receive a longitudinal member, and a side opening configured to receive the anchor head;
• sliding two or more housings onto a longitudinal member, the longitudinal member configured to extend through the second passages in the housings;
• positioning the longitudinal member with the two or more housings disposed thereon adjacent the anchors such that each housing is adjacent an anchor head;
• sliding the housings onto the anchor heads with the anchor heads being received in the side openings;
• and
• securing the housings and longitudinal member to the anchor heads;
• wherein the housing has a seat formed by walls of the housing at the lower opening being tapered toward the first passage, the seat configured to receive a bottom surface of the anchor head and prevent the anchor from moving laterally out of the housing, wherein securing the housings includes moving the housing axially away from the anchor to position the anchor head in the seat.

A method for treating the spine of a patient, the method comprising:

• advancing at least one access device through a first incision in the skin of the patient, the access device having a proximal end and a distal end and a path extending therebetween, advancing the access device until the distal end is adjacent at least first and second vertebral target sites;
• inserting two or more anchors along the path through the access device and securing the anchors to the patient's vertebrae at the first and second vertebral target sites, each anchor having a head and a shaft, the shaft being secured to the vertebra;
• providing a longitudinal member and two or more housings, the longitudinal member configured for insertion through the two or more housings, each housing having a first passage extending longitudinally therethrough between an upper opening and a lower opening, a second passage transverse to the first passage and configured to receive the longitudinal member, and a side opening configured to receive the anchor head;
• inserting the longitudinal member with housings disposed thereon through the access device until a distal end of the longitudinal member is adjacent the first target site;
• advancing the distal end of the longitudinal member to the second target site, until a proximal end of the longitudinal member is adjacent the first target site, the distal end of the longitudinal member is adjacent the second target site, and each housing is adjacent an anchor head;
• sliding each housing onto an anchor head such that the anchor head enters the side opening;
• and
• securing the housings and longitudinal member to the anchor heads.