Tensioner-balancer for knee joint

A knee gap tensioning apparatus, comprising:

• a tensioner-balancer, including:
• a baseplate;
• a top plate;
• and
• a linkage interconnecting the baseplate and the top plate and operable to move the top plate relative to the bottom plate between retracted and extended positions in response to application of an actuating force, the linkage including:
• a first toggle linkage, including:
• a lower link having a first end and a second end, the first end pivotally connected to the baseplate;
• an upper link having a first end and a second end, the first end pivotally connected to the top plate, wherein the second ends of the first and second links are pivotally connected to each other;
• a second toggle linkage, including:
• a lower link having a first end and a second end, the first end pivotally connected to the baseplate;
• an upper link having a first end and a second end, the first end pivotally connected to the top plate, wherein the second ends of the first and second links are pivotally connected to each other;
• a connector linkage interconnecting the first and second toggle linkages;
• wherein the links of the linkage comprise parallel pivot axes;
• wherein the linkage is configured so as to produce linear movement of the top plate relative to the base plate, in response to a rotational movement of one or more of the links;
• wherein the linkage includes an input shaft coupled to the linkage and configured to accept a rotary input about an axis parallel to the parallel pivot axes of the links of the linkage;
• and
• at least one sensor operable to measure a distraction load applied by the tensioner-balancer.