Surgical aid for joints

A surgical aid for joints, comprising:

• a first element (10), intended to be positioned in contact with a first bone of a joint;
• a second element (20), intended to be positioned in contact with a second bone of the joint;
• the first and second element (10,20) are movable relative to one another along at least a first direction (X);
• a displacement sensor (30) predisposed for measuring a relative displacement between the first and second element (10, 20);
• an actuator or motor (50) predisposed for exerting a force that tends to move away the first element (10) and second element (20) from one another;
• a force sensor (51) suitable for detecting the force exerted by the actuator or motor (50);
• a processing module (60) which receives in input signals emitted by the displacement sensor (30) and pressure sensor (40) and which is predisposed for controlling the actuator or motor (50);
• wherein the processing module (60) is predisposed for detecting the signals of the displacement sensor (30) and signals of the force sensor (51) and for processing a force/displacement diagram, which puts into correspondence a force value applied by the actuator or motor (50), which force is obtained from a value detected by the force sensor (51), with a corresponding displacement value detected by the displacement sensor (30);
• wherein the processing module (60) is arranged to store, in at least two bending positions, the force/displacement diagram by detecting a displacement wherein the diagram exhibits a change of slope;
• characterized in that the processing module (60) is provided with an algorithm to process the displacement values recorded and stored for each angular position to obtain a displacement which corresponds to a maximum tibiofemoral distance in which capsule-ligamentous tissues are maintained in conditions of isometric tension.