A surgical apparatus comprising a first distraction mechanism, a second distraction mechanism, and a third distraction mechanism. The surgical apparatus is configured to be placed in a joint of the musculoskeletal system to precisely separate the first bone from the second bone to support one or more bone cuts for installing a prosthetic joint. The first distraction mechanism simultaneously changes a height of a first side and a second side of the joint. The change in height is equal on the first and second sides. The second distraction mechanism changes the height on the first side of the joint but not the second side. The third distraction mechanism changes the height of the second side of the joint but not the first side. The surgical apparatus further includes at least one module to measure loading applied by the joint to the surgical apparatus.