An orthopaedic surgical instrument that includes a patella resection guide is disclosed. The patella resection guide includes a body having a substantially planar upper surface that defines a patella cutting guide surface and a first jaw having a first tooth, and a second jaw positioned opposite the first jaw. The second jaw is movable relative to the first jaw and includes a second tooth extending toward the first tooth that defines an axis along which the second jaw is moveable relative to the first jaw. The patella cutting guide surface defines a resection plane that extends through a patient's patella when the patella is positioned between the first jaw and the second jaw.