Undercutting surgical instrument

Abstract

An undercutting surgical instrument comprises a housing disposed along a longitudinal axis between a proximal region and a distal section which is sized to be inserted into a hole in a bone. A passage with an open end at the distal section is disposed through the housing along an axis to receive a guide wire for positioning the distal section adjacent to the bone. A plurality of axially extending slots in walls of the housing are arranged around the passage and extend between the proximal region and the distal section of the housing, and receive a plurality of axially extending arms. A proximal region of each arm is pivotally mounted to the housing, and a distal end of each arm carries a cutting tool so that the cutting tools are arranged around the open end of the passage (and the guide wire). An actuator is movably disposed within the passage and coupled to selectively pivot the arms transversely to the axis so that the cutting tools are moved between a retracted position (in the slots) and a deployed position (in which the cutting tools protrude from the slots). The actuator is also rotatably coupled to the housing to rotate the distal section and the deployed cutting tools to form an undercut in the bone hole around the guide wire. The instrument is highly effective in forming an undercut hole shaped to securely receive a tissue plug, such as a cartilage plug, during procedures to repair the articular cartilage of a joint. The undercut receives a lip on the tissue plug, and thus holds the plug in the hole without requiring external anchoring (e.g., suture or pins).

Dependencies are inferred from the claim text.