Abstract: A system including a knee ranging tool: including a base configured to locate on a resected proximal face of a tibia in a knee of a patient; defining a tibial reference surface configured to run against a femoral surface of an artificial femoral component, installed on a distal face of a femur of the patient, during articulation of the knee of patient; including a set of stages interposed between the base and the tibial reference surface, configured to locate the tibial reference surface relative to the base, and compliant to medial-lateral translation, anteroposterior translation, and transverse rotation; and configured to indicate a medial-lateral translation offset, an anteroposterior translation offset, and a transverse rotation offset corresponding to a position of the tibial reference surface, relative to the base, that yields elastic deformation of ligaments in the knee over a range of motion of the knee.

Abstract: Methods and devices are disclosed for soft tissue balancing of a knee joint during an arthroplasty procedure that include balancing the knee joint at or near mid-flexion, while maintaining the rotational position of the femur with respect to the tibia that replicates proper kinematic placement of these bones. Also disclosed are methods and devices for soft tissue balancing of a knee joint during an arthroplasty procedure that include balancing the knee joint at or near mid-flexion using one or more expansion devices that are not actively requiring monitoring and/or recording of forces applied by the bodily tissues, but instead uses incremental changes in actual length/height of the expansion device to determine whether the joint is properly tensioned or too lax.

Abstract: Methods and devices are disclosed for soft tissue balancing of a knee joint during an arthroplasty procedure that include balancing the knee joint at or near mid-flexion, while maintaining the rotational position of the femur with respect to the tibia that replicates proper kinematic placement of these bones. Also disclosed are methods and devices for soft tissue balancing of a knee joint during an arthroplasty procedure that include balancing the knee joint at or near mid-flexion using one or more expansion devices that are not actively requiring monitoring and/or recording of forces applied by the bodily tissues, but instead uses incremental changes in actual length/height of the expansion device to determine whether the joint is properly tensioned or too lax.

Abstract: Joint balancing methods and apparatus for arthroplasty procedures are disclosed. An example knee balancing jig may include a tibial placement guide configured for mounting to a tibial reference in a generally medial-lateral orientation in position generally anterior to a knee and/or at least one balancing assembly. The balancing assembly may include a vertical guide configured to releasably mount to the tibial placement guide in a generally inferior-superior orientation, at least one posteriorly extending paddle selectively vertically movable along the vertical guide, the paddle configured to selectively engage a distal femur and/or a proximal tibia, and/or at least one pin guide selectively vertically movable along the vertical guide, the at least one pin guide comprising at least one opening configured to receive at least one of a drill bit and a bone pin therethrough.

Abstract: Methods and devices are disclosed for soft tissue balancing of a knee joint during an arthroplasty procedure that include balancing the knee joint at or near mid-flexion, while maintaining the rotational position of the femur with respect to the tibia that replicates proper kinematic placement of these bones. Also disclosed are methods and devices for soft tissue balancing of a knee joint during an arthroplasty procedure that include balancing the knee joint at or near mid-flexion using one or more expansion devices that are not actively requiring monitoring and/or recording of forces applied by the bodily tissues, but instead uses incremental changes in actual length/height of the expansion device to determine whether the joint is properly tensioned or too lax.

Abstract: Methods and devices are disclosed for soft tissue balancing of a knee joint during an arthroplasty procedure that include balancing the knee joint at or near mid-flexion, while maintaining the rotational position of the femur with respect to the tibia that replicates proper kinematic placement of these bones. Also disclosed are methods and devices for soft tissue balancing of a knee joint during an arthroplasty procedure that include balancing the knee joint at or near mid-flexion using one or more expansion devices that are not actively requiring monitoring and/or recording of forces applied by the bodily tissues, but instead uses incremental changes in actual length/height of the expansion device to determine whether the joint is properly tensioned or too lax.

Abstract: Joint balancing methods and apparatus for arthroplasty procedures are disclosed. An example apparatus includes a knee arthroplasty set of guides comprising: (a) a femoral guide configured to mount to a distal femur, and (b) a tibial guide configured to mount to a proximal tibia, where the femoral guide and the tibial guide are configured to engage one another and lock in an angle between a longitudinal axis of the distal femur and a longitudinal axis of the proximal tibia of 30-70 degrees.

Abstract: A method for generating intraoperative surgical guidance during a knee arthroplasty includes: preceding resection of a first bone and a second bone in a knee of a patient, generating a first ligament tension curve for a first ligament in the knee; generating a second ligament tension curve for a second ligament in the knee; storing a first target tension curve for the first ligament based on the first ligament tension curve; and, succeeding resection of the first bone and succeeding placement of a first test implant on the first bone, generating a third ligament tension curve for the first ligament; characterizing a first phase difference between the third ligament tension curve and the first target tension curve; and in response to the first phase difference exceeding a threshold negative phase difference, outputting a first prompt to a surgeon to further resect the first bone proportional to the first phase difference.

Abstract: Once variation of a system for total knee replacement includes: a first alignment guide defining first set of guides that locate a first set of pins on a first bone of a joint in extension and defining a reference surface relative to the first set pin guides; a second alignment guide constrained relative to the first alignment guide by the reference surface and defining a second set of guides, relative to the first set of guides, that locate a second set of pins on a second bone of the joint; a first cut guide located by the first set of pins and defining a first cut plane for resecting the first bone; and a second cut guide located by the second set of pins and defining a second cut plane, linearly offset from the first cut plane, for resecting the second bone.

Abstract: Joint balancing methods and apparatus for arthroplasty procedures are disclosed. An example method of preparing a knee to receive a knee implant includes: (a) positioning a knee comprising a distal femur and a proximal tibia at a mid-flexion angle; (b) performing soft tissue balancing of the knee at the mid-flexion angle; (c) determining a location of a posterior chamfer cut of the distal femur configured to engage the posterior chamfer angle of a femoral component of a knee implant based at least in part upon the soft tissue balancing of the knee at the mid-flexion angle; and, (d) resecting the distal femur to create the posterior chamfer cut.

Abstract: Joint balancing methods and apparatus for arthroplasty procedures are disclosed. An example knee balancing jig may include a tibial placement guide configured for mounting to a tibial reference in a generally medial-lateral orientation in position generally anterior to a knee and/or at least one balancing assembly. The balancing assembly may include a vertical guide configured to releasably mount to the tibial placement guide in a generally inferior-superior orientation, at least one posteriorly extending paddle selectively vertically movable along the vertical guide, the paddle configured to selectively engage a distal femur and/or a proximal tibia, and/or at least one pin guide selectively vertically movable along the vertical guide, the at least one pin guide comprising at least one opening configured to receive at least one of a drill bit and a bone pin therethrough.