POLYAXIAL BONE ANCHOR WITH POP-ON SHANK AND FRICTION FIT RETAINER WITH LOW PROFILE EDGE LOCK

摘要

A polyaxial bone screw assembly includes a threaded shank body having an integral upper portion receivable in an integral receiver, the receiver having an upper channel for receiving a longitudinal connecting member and a lower cavity cooperating with a lower opening. A down- loadable compression insert, a down-loadable friction fit split retaining ring having inner and outer tangs and an up- loadable shank upper portion cooperate to provide for pop- or snap-on assembly of the shank with the receiver either prior to or after implantation of the shank into a vertebra. The shank and receiver once assembled cannot be disassembled.