Sensorized knee arthroplasty utilizing an intraoperative sensor system
Systems and techniques can be provided to generate sensorized insights into the characteristics of a knee joint space during a knee replacement procedure. In some implementations, a sensor support body carrying one or more sensors can be used to measure and inform the clinician of the varus/valgus angles of the tibia and femur, allowing the clinician to adjust the surgical procedure to accommodate the measured angles. The clinician may simulate changes to the load balance across the knee joint in response to potential dimensional changes to the knee joint prior to actually surgically implementing the changes.
1 . A method of performing bone alignment during a knee arthroplasty procedure, the method comprising:
resecting each of a tibia and a femur defining a tibiofemoral joint;
inserting a sensor support body carrying a position sensor into the tibiofemoral joint with an alignment rod extending through the sensor support body;
rotating the sensor support body in a medial-to-lateral direction until a tip of the alignment rod is positioned at a center of a femoral head of the femur and thereafter capturing a varus/valgus angle of the femur in a coronal plane using the position sensor; and
rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at a center of an ankle and thereafter capturing a varus/valgus angle of the tibia in the coronal plane using the position sensor.
2 . The method of claim 1 , wherein the position sensor comprises a three-axis accelerometer.
3 . The method of claim 1 , wherein rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the femoral head of the femur comprises pressing the sensor support body against a cut face of the femur in the tibiofemoral joint, optionally with one or more features positioned between the sensor support body and the cut face of the femur.
4 . The method of claim 1 , wherein rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the femoral head of the femur comprises rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned over the center of the femoral head of the femur.
5 . The method of claim 1 , wherein rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the ankle comprises pressing the sensor support body against a cut face of the tibia in the tibiofemoral joint, optionally with one or more features positioned between the sensor support body and the cut face of the tibia.
6 . The method of claim 1 , wherein rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the ankle comprises rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned over the center of the ankle.
7 . The method of claim 1 , wherein:
rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the femoral head of the femur and thereafter capturing the varus/valgus angle of the femur comprises rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the femoral head of the femur and thereafter capturing the varus/valgus angle of the femur with the tibiofemoral joint in extension; and
rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the ankle and thereafter capturing the varus/valgus angle of the tibia comprises rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the ankle and thereafter capturing the varus/valgus angle of the tibia with the tibiofemoral joint in extension.
8 . The method of claim 1 , further comprising an electronics housing containing the position sensor.
9 . The method of claim 8 , wherein the electronics housing is configured to detachably couple to the sensor support body.
10 . The method of claim 1 , further comprising displaying via a display of a computing device at least one of the varus/valgus angle of the femur, the varus/valgus angle of the tibia, and a mechanical axis of the tibiofemoral joint.
11 . The method of claim 10 , comprising displaying the varus/valgus angle of the femur, the varus/valgus angle of the tibia, and the mechanical axis of the tibiofemoral joint.
12 . The method of claim 1 , wherein rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the femoral head of the femur and thereafter capturing the varus/valgus angle of the femur comprises rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the femoral head of the femur and thereafter capturing the varus/valgus angle of the femur before rotating the sensor support body in the medial-to-lateral direction until the tip of the alignment rod is positioned at the center of the ankle and thereafter capturing the varus/valgus angle of the tibia.
13 . The method of claim 1 , comprising:
pressing the sensor support body against a cut face of the tibia in the tibiofemoral joint, optionally with one or more features positioned between the sensor support body and the cut face of the tibia;
tilting a proximal portion of the sensor support body toward the femur; and
capturing a tilt angle of the tibia in a sagittal plane using the position sensor.
14 . The method of claim 13 , further comprising displaying via the display of the computing device the tilt angle.
15 . The method of claim 1 , further comprising inserting the sensor support body carrying at least one force sensor into the tibiofemoral joint with both the tibia and the femur resected and measuring a force across the tibiofemoral joint.
16 . The method of claim 15 , wherein inserting the sensor support body carrying at least one force sensor into the tibiofemoral joint comprises inserting the sensor support body carrying at least one force sensor into the tibiofemoral joint after capturing the varus/valgus angle of the femur and after capturing the varus/valgus angle of the tibia.
17 . The method of claim 15 , wherein:
the at least one force sensor comprises a medial force sensor and a lateral force sensor; and
measuring the force across the tibiofemoral joint comprises measuring a medial compartment force via the medial force sensor and a lateral compartment force via the lateral force sensor.
18 . The method of claim 17 , wherein:
the medial force sensor comprises a medial anterior force sensor and a medial posterior force sensor;
the lateral force sensor comprises a lateral anterior force sensor and a lateral posterior force sensor; and
measuring the force across the tibiofemoral joint comprises measuring a medial anterior force via the medial anterior force sensor, a medial posterior force via the medial posterior force sensor, a lateral anterior force via the lateral anterior force sensor, and a lateral posterior force via the lateral posterior force sensor.
19 . The method of claim 15 , comprising:
receiving, via a user interface of a computing device, a user input simulating a change in a dimensional characteristic of the tibiofemoral joint;
determining, with one or more processors, the force across the tibiofemoral joint projected in response to the change in the dimension characteristic; and
displaying, via a display of the computing device, the force across the tibiofemoral joint projected in response to the change in the dimension characteristic.
20 . The method of claim 19 , wherein the change in the dimensional characteristic comprises:
a change in the varus/valgus angle of the tibia;
a change in the varus/valgus angle of the femur; and/or
a change in a spacing between the tibia and the femur across the tibiofemoral joint.
21 . The method of claim 20 , wherein the change in the spacing between the tibia and the femur across the tibiofemoral joint comprises at least one of:
a change in an amount of bone resected from the tibia and/or femur; and/or
a change in a thickness of a prosthetic bearing to be inserted between a femoral prosthetic component to be installed on the femur and a tibial prosthetic component to be installed on the tibia.
22 . The method of claim 19 , wherein:
the at least one force sensor comprises a medial force sensor and a lateral force sensor;
measuring the force across the tibiofemoral joint comprises measuring a medial compartment force via the medial force sensor and a lateral compartment force via the lateral force sensor;
determining, with one or more processors, the force across the tibiofemoral joint projected in response to the change in the dimension characteristic comprises determining the medial compartment force projected in response to the change in the dimension characteristic and determining the lateral compartment force projected in response to the change in the dimension characteristic; and
displaying, via the display of the computing device, the force across the tibiofemoral joint projected in response to the change in the dimension characteristic comprises displaying the medial compartment force projected and the lateral compartment force projected.
23 . The method of claim 19 , wherein determining, with one or more processors, the force across the tibiofemoral joint projected in response to the change in the dimension characteristic comprises referencing a database relating different force values to different tibiofemoral joint dimensional characteristics.
24 . The method of claim 19 , further comprising further resecting at least one of the tibia and the femur to implement the change in the dimensional characteristic of the tibiofemoral joint simulated.