An orthopaedic surgical device (10) for determining the joint force of a patients knee joint includes a tibial paddle (34) shaped to be positioned in the patients knee joint and a handle (32) extending from the tibial paddle. The tibial paddle includes a sensor array (90) positioned therein and configured to generate sensor signals indicative of the joint force of the patients knee joint. The device also includes a control circuit (92) configured to control a display located on the handle to provide a visual indication of the medial and lateral balance of the joint force. Various tibial trialing components (504) may be coupled to the tibial paddle along with an associated adaptor (502).