In an exemplary embodiment, the present invention provides a fastener assembly that can be used for the fixation or anchoring of orthopedic devices or instruments to bone tissue. In particular, the present invention preferably provides a low profile variable angle or fixed angle fastener assembly that is able to securely connect the orthopedic device to bone tissue. Furthermore, in an exemplary embodiment, the present invention provides a fastener assembly having a locking mechanism that will quickly and easily lock the fastener assembly with respect to the orthopedic device.