Arthroscopic procedures often require soft tissue to be reattached to bone. To achieve this, anchors are typically placed in the bone and sutures attached to the anchor are passed through the tissue to securely retain the tissue in place. Typical anchors may be pound-in or screw-in type anchors, or combinations of both. However, a combination pound-in/screw-in type anchor can fail during insertion if the threaded, screw-in portion of the anchor is over-inserted by the driver assembly. Furthermore, while some contact between the threads of the anchor and the bone surface is necessary to screw the anchor into the bone, too much axial force can damage the threads, impairing the overall function of the anchor.
Some current driver assemblies, in attempting to control anchor over-insertion, rely on visual markers. These visual markers typically include laser marks on the distal end of the anchor and/or driver. However, these visual markers cannot protect the anchor from damage if they are not clearly visible, or are disregarded by the user. Driver assemblies with internal springs have also been developed to provide axial compliance of the inserter shaft to protect the anchor from over-insertion. However, with higher spring loads, friction between the knob which advances the threaded portion of the anchor and the handle grip may cause the knob to be difficult to turn.