An orthopaedic surgical device for determining the joint force of a patient's knee joint includes a tibial paddle shaped to be positioned in the patient's knee joint and a handle extending from the tibial paddle. The tibial paddle includes a sensor array positioned therein and configured to generate sensor signals indicative of the joint force of the patient's knee joint. The orthopaedic surgical device also includes a control circuit configured to control a display located on the handle to provide a visual indication of the medial and lateral balance of the joint force. In some embodiments, various tibial trialing components may be coupled to the tibial paddle along with an associated adaptor.