A bone cutting assembly includes a guide pin that may be securely inserted into a bone to define a cutting axis. The bone cutting assembly also includes a housing having a cam surface and features for temporarily fastening the housing to the bone. The bone cutting assembly also includes a burr mounting arm that rotatably and slidably fits onto the guide pin so that the arm can swing around the cutting axis and also translate up and down the guide pin. A user may move the burr mounting arm about the cutting axis so that the arm follows along the cam surface of the housing.
