1. An insert for balancing a joint during repair of the joint, the insert comprising: a top plate configured to interface with a bone structure of a joint; a bottom plate spaced apart from the top plate and configured to interface with an opposing bone structure of the joint; a pneumatic actuator including a first bellows made of an inflatable material, the first bellows configured to inflate and distribute a pneumatic force to the top plate and to the bottom plate; and one or more sensors for determining a spatial relationship between the top plate and the bottom plate.