A modular spacer device for a knee joint includes a tibial element adapted to be constrained to an end of the tibial bone and a femoral element adapted to be constrained to an end of the femoral bone and to be articulated on the tibial element. The tibial element has first and second surfaces opposite to each other, and the femoral element has first surface and second surfaces opposite to each other. The first surface of the femoral element is convex and laterally has a curved, ammonite-shaped contour with a curvature radius that increases starting from a rear section with a curvature radius R1, a first central section having a curvature radius R2, a second central section having a curvature radius R3, and a front section having a curvature radius R4, with R1≤R2≤R3≤R4.

An orthopaedic tibial prosthesis includes a tibial baseplate with an asymmetric periphery which promotes proper positioning and orientation on a resected tibia, while also facilitating enhanced kinematics, soft-tissue interaction, and long-term fixation of the complete knee prosthesis. The asymmetric baseplate periphery is sized and shaped to substantially match portions of the periphery of a typical resected proximal tibial surface, such that proper location and orientation is evident by resting the baseplate on the tibia. The baseplate periphery provides strategically positioned relief and/or clearance between the baseplate periphery and bone periphery, such as in the posterior-medial portion to prevent deep-flexion component impingement, and in the anterior-lateral portion to avoid undue interaction between the anatomic iliotibial band and prosthesis components.

Embodiments of the invention include a knee arthroplasty trialing system and method with a femoral component and a tibial trial that has one or more spacers and one or more articular trials. Some embodiments include spacers and articular trials that may be moved in and out of the joint space without significantly distracting the femoral component away from the tibial trial. Some spacers and trials are configured to be inserted and removed from a joint space substantially along an anterior-posterior axis.

Methods and devices are disclosed relating improved articular models, implant components, and related guide tools and procedures. In addition, methods and devices are disclosed relating articular models, implant components, and/or related guide tools and procedures that include one or more features derived from patient-data, for example, images of the patient's joint. The data can be used to create a model for analyzing a patient's joint and to devise and evaluate a course of corrective action. The data also can be used to create patient-adapted implant components and related tools and procedures.

A knee joint prosthesis for a tibia and femur can include a tibial component, a tibial bearing, and a post. The tibial bearing can include a first bearing portion, a second bearing portion, and an aperture. The first bearing portion can be positionable on a first side of the sagittal axis and can have a first shape. The second bearing portion can be positionable on a second side can have a second shape different than the first shape. The post, together with the first bearing portion and the second bearing portion, can be configured to promote the femur to pivot substantially about the first bearing portion.

An orthopaedic knee prosthesis includes a tibial insert and a femoral component configured to articulate on the tibial insert. The tibial insert includes a lateral articular surface and medial articular surface that is asymmetrically shaped relative to the lateral articular surface. The medial articular surface is shaped to reduce anterior translation of a medial condyle of the femoral component, while the lateral articular surface is shaped to allow a lateral condyle of the femoral component to pivot, relative to the medial articular surface, along an arcuate articular path. Additionally, one or both condyles of the femoral component may include a femoral articular surface having a curved femoral surface section defined by a continuously decreasing radius of curvature.

An orthopaedic surgical system for a total knee implant includes a plurality of commonly-sized femoral trial components. Each commonly-sized femoral trial component includes a first femoral condyle having a first articulation surface configured to engage a tibial component, and a second femoral condyle may be spaced apart from the first femoral condyle. The second femoral condyle has a second articulation surface configured to engage the tibial component. An anterior cam is positioned between the first femoral condyle and the second femoral condyle. A method of using such a system is also disclosed.

Medical implants and methods for forming medical implants with additive manufacturing techniques are provided herein. The medical implants include arranging grain orientations of the materials of the medical implants to enhance strength characteristics of the medical implants or to reduce material requirements. The medical implant may be formed by heating a first portion of a granulized material along a first build pathway to melt the material such that grains of the material are oriented along the first build pathway after the melted material cools and heating a second portion of the granulized material along a second build pathway to melt the material such that grains of the material are oriented along the second build pathway oriented substantially transverse to the build pathway of the first portion after the melted material cools. The first and second build pathways may be a series of substantially overlapping melting events.

A bone cut system comprising a distractor, one or more drill guides, one or more bone cutting jigs, a computer, and a display. The distractor includes electronic circuitry configured to control a measurement process and transmit measurement data. The distractor can include a magnetic distance sensor, a magnetic angle sensor, and load sensors configured to measure a distraction distance, medial-lateral angle, load magnitude applied to the distractor, and position of load in real-time. The distractor equalizes a medial and lateral compartment of a knee joint in flexion or extension at a predetermined loading. Guide holes are drilled to support cuttings with the medial and lateral compartments equalized. The distractor is configured to support one or more bone cuts using cutting jigs coupled to the guide holes that supports installation of a prosthetic component in alignment with a mechanical axis of a leg.

A knee joint prosthesis is capable of moving between an extended position and a flexion position. The knee joint prosthesis includes a femoral component that is configured to be mounted to a femur, a tibial component that is configured to be mounted to a tibia, a post fixedly connected to one of the femoral component and the tibial component, and a cam recess defined on the other of the femoral component and the tibial component that is configured to be engaged by the post in either the extended position or the flexion position of the knee joint prosthesis. The knee joint prosthesis may also include an artificial ligament that extends between the femoral component and the tibial component. The post and the ligament mimic one of the ACL and PCL.