Provided is a spacer device for assisting a surgeon during knee surgery on a patient, the spacer device having a housing, a support portion and an electronic force sensor. The housing includes a lateral member having an outer surface and an inner surface and a pair of side members that comprise respective, internal, opposed side walls. The support portion includes a first end portion disposed between the side walls of the housing and including a first pair of lateral projections and a second end portion. The support portion is further adapted for axial slidable movement relative to the housing so as to define a first space and a second space between a first pair of lateral projections and respective side members for receiving one or more spacer elements therein. A surgical system including the spacer device as well as methods of using same are also provided.