Abstract: A hand-held display module includes a housing, a display coupled to the housing, and a circuit positioned in the housing and coupled to the display. The circuit includes a receiver circuit configured to communicate with a sensor module positioned in a knee joint of a patient to receive joint force data indicative of the joint force of the patient's knee joint. In one mode, the circuit is configured to display a visual indication of the medial-lateral balance of the joint force based on the joint force data. In a second mode, the circuit is configured to display a visual indication of the medial-lateral and the anterior-posterior balance of the joint force.