Computer aided orthopedic surgery system having a joint distraction device
An orthopedic distraction device is provided. The orthopedic distraction device includes a first upper paddle for engaging a first bone of a joint, a lower paddle for engaging a second bone of the joint and a displacement mechanism. The displacement mechanism includes a drive assembly operable to move the upper paddle relative to the lower paddle. The lower paddle is releasably connected to the displacement mechanism.
1 . A system for assessing laxity of a joint comprising:
a pair of arms for engaging a first bone and a second bone of the joint;
a force sensor for measuring a force applied by at least one of the pair of arms;
a three-dimensional position tracking system for tracking a position of the first bone and the second bone of the joint;
a memory having computer program instructions; and
a processor programmed to execute the computer program instructions to:
receive data regarding a relative position of the first and second bones of the joint while being distracted by the pair of arms,
receive a target force to be applied by the pair of arms,
display a measured force of the force sensor,
calculate a gap distance based on the relative position of the first and second bones, and
display the measured force in relation to the target force and the gap distance on a display.
2 . The system of claim 1 , wherein each arm comprises a tine.
3 . The system for assessing laxity of a joint of claim 1 , wherein the calculated gap distance is a predicted gap distance further based on the measured force.
4 . The system for assessing laxity of a joint of claim 3 , wherein the predicted gap distance defines a gap spacing between a virtual femoral implant and a virtual tibial implant associated with the first and second bones of the joint.
5 . The system for assessing laxity of a joint of claim 3 , wherein the processor is further programmed to execute the computer program instructions to display the predicted gap as a function of flexion angle of the joint.
6 . The system of claim 1 , wherein the pair of arms comprise an upper arm having a distal end and a lower arm having a distal end, both arms being either laterally or medially located relative to the first and the second bones, wherein the distal ends inter-lie relative to one another.
7 . The system of claim 6 , wherein the distal ends of the upper arm and lower arm inter-lie such that an overall height of the distal ends of the upper arm and lower arm is less than a sum of the individual heights of each of the distal ends of the upper arm and lower arm.
8 . The system of claim 1 , wherein the processor is further programmed to compare the target force to the measured force to determine a next force to be applied by the at least one of the pair or arms.
9 . The system of claim 8 , wherein the next force applied by the at least one of the pair of arms is determined according to an error between the target force and the measured force.
10 . The system of claim 8 , wherein the next force will be applied by the at least one of the pair of arms if the measured force is lower than the target force, and next forces will be applied until the measured force approaches the target force, wherein, as the actual, measured force approaches the target force, the error decreases, thereby decreasing a rate of actuation until actual, measured force equals target force.
11 . A system for assessing laxity of a joint comprising:
an upper paddle and a lower paddle for engaging a first bone and a second bone of a joint;
a force sensor for measuring a force applied by at least one of the upper and the lower paddles;
a three-dimensional position tracking system for tracking a position of the first bone and the second bone of the joint; and
a computer having a memory with computer program instructions and a processor programmed to execute the computer program instructions to:
receive, as a user input, a target force to be applied by the at least one of the upper and the lower paddles;
receive, from the force sensor, an actual, measured force applied by the at least one of the upper and the lower paddles;
receive, from the three-dimensional position tracking system, the position of the first bone and the second bone of the joint;
calculate a gap distance based an a relative position of the first and the second bones; and
display the measured force in relation to the target force and the associated gap distance on a display.
12 . The system for assessing laxity of a joint of claim 11 , wherein the processor is further programmed to execute the computer program instructions to display a relative position of the first and second bones of the joint at various degrees of flexion or the measured force applied by the at least one of the upper paddle and lower paddle.
13 . The system for assessing laxity of a joint of claim 11 , wherein each of the upper paddle and lower paddle are either laterally or medially located relative to the first and the second bones of the joint, each paddle having distal ends that inter-lie such that an overall height of the distal ends of the upper paddle and lower paddle is less than a sum of the individual heights of each of the distal ends of the upper paddle and lower paddle.
14 . The system of claim 11 , wherein the upper paddle and the lower paddle each have a distal end, where the distal ends of the respective upper and lower paddles are configured to be aligned either one on top of another, or to inter-lie relative to one another.
15 . The system of claim 11 , wherein the processor is further programmed to compare the target force to the measured force to determine a next force to be applied by the at least one of the upper and the lower paddles.
16 . The system of claim 15 , wherein the next force applied by the at least one of the upper and the lower paddles is determined according to an error between the target force and the measured force.
17 . The system of claim 15 , wherein the next force will be applied by the at least one of the upper and the lower paddles if the measured force is lower than the target force, and next forces will be applied until the measured force approaches the target force, wherein, as the actual, measured force approaches the target force, the error decreases, thereby decreasing a rate of actuation until actual, measured force equals target force.
18 . A system for assessing laxity of a joint comprising:
a pair of arms, each arm including a proximal portion and a distal portion, wherein the pair of arms is configured to move between a compressed configuration for insertion between first and second bones and an expanded configuration for distraction of the first and second bones in response to a force applied to at least one of the proximal portions, wherein a distance between each of the pair of arms is greater in the expanded configuration than in the compressed configuration;
a force sensor coupled to one of the pair of arms and configured to collect force data related to the applied force; and
a processor and computer-readable medium storing computer program instructions that, when executed, cause the processor to execute the computer program instructions to:
receive a target force to be applied by the pair of arms,
display force data of the force sensor,
calculate a gap distance between the first and second bones, and
display the force data in relation to the target force and the gap distance on a display.
19 . The system for assessing laxity of a joint of claim 18 , wherein the calculated gap distance is a predicted gap distance based on the force data, and the processor further executes computer program instructions to display the predicted gap distance.
20 . The system for assessing laxity of a joint of claim 19 , wherein the predicted gap distance defines a gap spacing between a virtual femoral implant and a virtual tibial implant or a bone resection associated with the first and second bones of the joint.
21 . The system for assessing laxity of a joint of claim 19 , wherein the processor further executes computer program instructions to display the predicted gap distance as a function of flexion angle of the joint.
22 . The system for assessing laxity of a joint of claim 18 , wherein each of the pair of arms are either laterally or medially located relative to the first and the second bones of the joint, and the distal portion of each arm inter-lie such that an overall height of the distal ends of each arm is less than a sum of the individual heights of the distal portions of each arm.
23 . The system for assessing laxity of a joint of claim 18 , wherein the processor further executes computer program instructions to display the gap distance when the applied force measured by the force sensor is within a predefined value or threshold from the target force.