Bone Anchor Assembly and Methods of Use

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

• providing at least one access device for insertion 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, the access device being advanced until the distal end is adjacent at least first and second vertebral target sites;
• providing two or more anchors for insertion 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 configured for securing 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 and housings 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.