Knee balancing system using patient specific instruments
A system is disclosed to support installation of a prosthetic joint or a prosthetic component. The system includes at least one sensor to measure a parameter. The system uses one or more patient specific instruments in conjunction with a tensor to make one or more bone cuts. The patient specific instruments and tensor make the bone cuts such that an installed prosthetic joint is aligned, balanced, loaded correctly, and positioned optimally for performance and reliability. The use of the tensor simplifies the workflow required when using the patient specific instruments. In one embodiment, the patient specific instruments are bone cutting jigs configured for the patient anatomy.
1. A surgical orthopedic system comprising:
one or more patient specific instruments (PSI) formed for a patient, the patient specific instruments being formed using a 3D model of at least one bone of the patient;
a tensor having a distraction mechanism and a tilting mechanism wherein a knee joint of the patient is configured to be balanced using the tensor with a leg of the patient placed in flexion greater than 5 degrees and less than 80 degrees, and wherein a drill guide is configured to couple to the tensor, the tensor including one or more sensors;
a computer configured to receive measurement data from the sensors, and
a display coupled to the computer configured to display the measurement data.
2. The surgical orthopedic system of claim 1 wherein a pre-operative plan is provided and displayed on the display, wherein the pre-operative plan supports optimization of a tibial or femoral location, and wherein 3D imaging of the leg is used to design the one or more patient specific instruments (PSI).
3. The surgical orthopedic system of claim 2 wherein a PSI tibial resection guide is configured to support a resection of a proximal tibia of the leg.
4. The surgical orthopedic system of claim 1 wherein the leg is placed in flexion at approximately 10 degrees and wherein the tensor is configured to set a balance of the compartments of the knee joint.
5. The surgical orthopedic system of claim 4 wherein the leg is moved to extension, wherein one or more holes are drilled in a femur of the leg using the femoral drill guide, wherein the femoral drill guide has an anterior/posterior adjustment, wherein the femoral drill guide has a rotation adjustment, and wherein the one or more holes support a bone cut that yields equal compartment heights at the balance set by the tensor.
6. The surgical orthopedic system of claim 5 wherein one or more adjustments are made to increase a range of motion if the knee joint or leg cannot be placed in extension.
7. The surgical orthopedic system of claim 5 wherein one or more adjustments are made to decrease a range of motion if the knee joint or leg hyperextends.
8. The surgical orthopedic system of claim 5 wherein a PSI distal femoral guide is configured to be pinned to the femur using the one or more holes drilled in the femur and wherein the PSI distal formal guide is configured to resect the femur.
9. The surgical orthopedic system of claim 8 wherein the leg is placed in flexion at 90 degrees, wherein the tensor is configured to be inserted into the knee joint, wherein the tensor is configured to balance the knee joint with the leg in flexion at 90 degrees and wherein one or more holes are drilled in the femur of the leg in flexion at 90 degrees.
10. The surgical orthopedic system of claim 9 wherein the tensor is removed, wherein the PSI femoral guide is configured to be pinned to the femur using the one or more holes that were drilled in the femur of the leg when positioned at 90 degrees, and wherein the femur is resected.