Disclosed herein are systems and methods of patella arthroplasty. A navigated patella clamp used in an arthroplasty procedure includes first and second movable jaw members and an actuation member coupled to the first and second jaw members for moving the first and second jaw members along a plane toward and away from one another. The patella clamp further includes a tracker and adjustable stylus for positioning the clamp on a patient's patella below a desired resection plane. The adjustable stylus coupled to the clamp is used to check the position and orientation of the clamp with respect to the patella to ensure the correct amount of bone will be resected from the patella corresponding to the thickness of a patella component that will be implanted on the resected patella.