Abstract: A method for planning an arthroplasty procedure on a patient bone. The method may include accessing generic bone data stored in a memory of a computer, using the computer to generate modified bone data by modifying the generic bone data according to medical imaging data of the patient bone, using the computer to derive a location of non-bone tissue data relative to the modified bone data, and superimposing implant data and the modified bone data in defining a resection of an arthroplasty target region of the patient bone.

Abstract: A computer-implemented method of preoperatively planning a surgical procedure on a knee of a patient including determining femoral condyle vectors and tibial plateau vectors based on image data of the knee, the femoral condyle vectors and the tibial plateau vectors corresponding to motion vectors of the femoral condyles and the tibial plateau as they move relative to each other. The method may also include modifying a bone model representative of at least one of the femur and the tibia into a modified bone model based on the femoral condyle vectors and the tibial plateau vectors. And the method may further include determining coordinate locations for a resection of the modified bone model.

Abstract: A method for planning an arthroplasty procedure on a patient bone. The method may include accessing generic bone data stored in a memory of a computer, using the computer to generate modified bone data by modifying the generic bone data according to medical imaging data of the patient bone, using the computer to derive a location of non-bone tissue data relative to the modified bone data, and superimposing implant data and the modified bone data in defining a resection of an arthroplasty target region of the patient bone.

Abstract: A femoral head prosthesis is a multilayer composite having a metal neck stem component thread or press fit into a hollow rigid shell of metal or ceramic, a polymeric core filling the interior volume under the hollow rigid shell and around a forward part of the neck stem, and a smooth, void-free polymeric articulation layer of at most 12 mm over the exterior of the shell. The prosthesis is formed by a polymeric molding process wherein polymerizing resin or heated thermoplastic material is flowed in a mold through a set of holes through the hollow shell into the interior volume and around the shell's exterior. Once the resin has cured or the thermoplastic cooled, the stem, core, shell and articulation layer collectively form an integral prosthesis of a desired head diameter matching a patient's anatomy.

Abstract: A computer-aided method of pre-operative planning of hip joint replacement is provided for establishing, from patient-specific images, femoral and acetabular implant sizes and cut planes. Image slices of a patient's hip joint are obtained. Coordinate positions of selected femur and acetabulum points (e.g., femoral head center, major trochanter midpoint, femoral shaft midpoint, acetabular rim high points and lowest point) in the images are marked, which allows the planning tool to perform a best fit analysis to offer a range of suitable implant and surgical cut plane parameters for selection by a surgeon. Patient-specific surgical jigs can then be constructed for the proximal femur and acetabulum of the hip joint corresponding to a surgeon selection between standard, mini, short-stem, and resurfacing hip replacement components and in accord with the surgeon-selected parameters.

Abstract: The femoral neck preserving hip implant includes a polymer femoral head molded onto a femoral head base, which is attached to a femoral neck rod to be inserted into the femoral neck of a patient. A metal acetabular cup is inserted into an acetabulum anatomy of a pelvis. The femoral head interfaces with the acetabular cup as a smooth plastic-to-metal spherical-surface joint. A main body shaft to be inserted into a femoral shaft has a diagonal hole therethrough located at a center line of the femur's neck to receive the femoral neck rod at a specified angle. A secured lock mechanism in the main body shaft above the diagonal hole is screwed down to compressively engage the femoral neck rod. Both the diagonal hole and the end of the femoral neck rod may have a slight taper. The femoral neck rod also has a radially outward extending flange that forms a contact feature that sits upon the resection plane of the femoral neck to stabilize against axial force loading.

Abstract: A computer-aided pre-operative planning tool with interactive surgeon interface for total knee replacement implements a method that allows implant size selection, implant positioning, and surgical cut planes estimation (with construction of corresponding surgical jig), based upon a series of coronal, axial and sagittal image slices of a patient's leg. Limb alignment and corresponding surgical cut planes are defined based upon joint anatomical-matching analysis to minimize joint wear and restore a pre-arthritic alignment (rather than an always fully neutral alignment). Using the interface, a surgeon has the option to adjust the varus/valgus alignment within recommended bounds between the pre-arthritic and fully neutral alignments. Implant size may be selected based on a best fit to the patient's leg obtained from analysis of the images.

Abstract: A knee prosthesis for total knee replacement has femoral and tibial joint components. The femoral component has a medial condyle, a lateral condyle and an intercondylar recess between the condyles. The condyles in sagittal profile both have spiral outer surfaces, wherein the increasing anterior-to-posterior radii of curvature for the medial condyle is smaller than the corresponding radii of curvature for the lateral condyle. The tibial component has shallow concave medial and lateral condyle surfaces for receiving corresponding condyles of the femoral component as bearing surfaces when the femoral and tibial components are biased together under applied tension by ligaments. Posterior portions of each femoral condyle that contact the corresponding tibial condyle up to 90° flexion are substantially spherical in shape, with gradually increasing radii in coronal profile as flexion increases, while the anterior portions beyond 90° flexion are substantially elliptical in shape in coronal profile.

Abstract: A method of manufacturing an arthroplasty jig is disclosed herein. The method may include the following: generate a bone model, wherein the bone model includes a three dimensional computer model of at least a portion of a joint surface of a bone of a patient joint to undergo an arthroplasty procedure; generate an implant model, wherein the implant model includes a three dimensional computer model of at least a portion of a joint surface of an arthroplasty implant to be used in the arthroplasty procedure; assess a characteristic associated with the patient joint; generate a modified joint surface of the implant model by modifying at least a portion of a joint surface of the implant model according to the characteristic; and shape match the modified joint surface of the implant model and a corresponding joint surface of the bone model.

Abstract: A femur cutting jig mechanism (FCJM) is provided having a number N1 of spaced apart FCJM contact points that correspond to a number N1 of spaced apart femur contact points on at least one of a medial condyle, a lateral condyle, and a trochlear groove on the patient's knee. The FCJM contact points are positioned in contact with the knee contact points, and a cut bar mechanism is positioned in contact with the FCJM to provide a location and an angular orientation of a cut bar plane that is to be used to resection and remove a selected portion of the patient's, knee. The FCJM is removed from the patient's knee, and a selected portion of the patent's knee is resectioned and removed. The number N1 is at most 12 in some embodiments.

Abstract: Disclosed herein is an arthroplasty jig for use in an arthroplasty procedure on a bone of a patient that forms a ball and socket joint. The arthroplasty jig may include a customized mating region and a resection guide. The customized mating region and the resection guide are referenced to each other such that, when the customized mating region matingly engages a surface area of a proximal femur, the resection guide will be aligned to guide a resectioning of the proximal femur along a preoperatively planned resection plane.

Abstract: A femur cutting jig mechanism (FCJM) is provided having a number N1 of spaced apart FCJM contact points that correspond to a number N1 of spaced apart femur contact points on at least one of a medial condyle, a lateral condyle, and a trochlear groove on the patient's knee. The FCJM contact points are positioned in contact with the knee contact points, and a cut bar mechanism is positioned in contact with the FCJM to provide a location and an angular orientation of a cut bar plane that is to be used to resection and remove a selected portion of the patient's, knee. The FCJM is removed from the patient's knee, and a selected portion of the patent's knee is resectioned and removed. The number N1 is at most 12 in some embodiments.

Abstract: A cutting jig and corresponding method of manufacture is provided. The jig comprises a unitary piece combining a bone cutting guide defining a cut plane and a set of fins projecting from a jig substrate and terminating in curvilinear bone-jig contact surfaces for abutting articular surface features. The curvilinear surfaces are characterized by custom patient-specific parameters derived from measurements obtained from selected image slices of a patient's joint region such that the curvilinear surfaces establish one and only one mechanical self-locking position for the unitary piece. One obtains a series of image slices of a patient's joint region, then selects a set of slices that show specified articular surface features in the joint region. Patient-specific parameters obtained from measurements of the slices specify curvilinear bone-jig contact surfaces and a cut plane.

Abstract: Disclosed herein is a method of defining a mating surface in a first side of an arthroplasty jig. The mating surface is configured to matingly receive and contact a corresponding patient surface including at least one of a bone surface and a cartilage surface. The first side is oriented towards the patient surface when the mating surface matingly receives and contacts the patient surface. The method may include: a) identifying a contour line associated with the patient surface as represented in a medical image; b) evaluating via an algorithm the adequacy of the contour line for defining a portion of the mating surface associated with the contour line; c) modifying the contour line if the contour line is deemed inadequate; and d) employing the modified contour line to define the portion of the mating surface associated with the contour line.

Abstract: A computer-implemented method of preoperatively planning a surgical procedure on a knee of a patient including determining femoral condyle vectors and tibial plateau vectors based on image data of the knee, the femoral condyle vectors and the tibial plateau vectors corresponding to motion vectors of the femoral condyles and the tibial plateau as they move relative to each other. The method may also include modifying a bone model representative of at least one of the femur and the tibia into a modified bone model based on the femoral condyle vectors and the tibial plateau vectors. And the method may further include determining coordinate locations for a resection of the modified bone model.

Abstract: A method for planning an arthroplasty procedure on a patient bone. The method may include accessing generic bone data stored in a memory of a computer, using the computer to generate modified bone data by modifying the generic bone data according to medical imaging data of the patient bone, using the computer to derive a location of non-bone tissue data relative to the modified bone data, and superimposing implant data and the modified bone data in defining a resection of an arthroplasty target region of the patient bone.

Abstract: Jigs for guiding femur and tibia resectioning in knee surgery contain bone-jig contact surfaces and a cutting guide as a single unitary piece. Contact surfaces are curvilinear surfaces formed into ends of projections from a jig base. Each jig has three pairs of contact surfaces selected to abut low-wear, lateral and medial, articular surface features, such that only one self-locking position against the bone (or cartilage) is possible and the integral cutting guide will define only one cut plane for the resectioning. An improved rotational transformation that converts scan views into desired proper axes is based on projections of rotated coordinates onto the plane of rotation to produce parameters that closely correspond to the joint surfaces in the desired jig coordinates.

Abstract: Methods of manufacturing a custom arthroplasty resection guide or jig are disclosed herein. For example, one method may include: generating MRI knee coil two dimensional images, wherein the knee coil images include a knee region of a patient; generating MRI body coil two dimensional images, wherein the body cod images include a hip region of the patient, the knee region of the patient and an ankle region of the patient; in the knee coil images, identifying first locations of knee landmarks; in the body coil images, identifying second locations of the knee landmarks; run a transformation with the first and second locations, causing the knee coil images and body coil images to generally correspond with each other with respect to location and orientation.

Abstract: Arthroplasty jigs and related methods are disclosed. Some of the arthroplasty jigs may comprise a jig body that is configured to align with a surface of a bone, and a positioning component. Certain of the methods may comprise providing such an arthroplasty jig, and aligning the jig body with a surface of a bone so that the positioning component provides at least one of a visible, audible, or tactile indication that such alignment has been achieved. Some of the arthroplasty jigs may comprise a jig body that is configured to align with a surface of a bone, and that is marked with identifying information. Certain of the methods may comprise providing an arthroplasty jig comprising a jig body that is configured to align with a surface of a bone, or providing an arthroplasty jig blank, and marking the arthroplasty jig or the arthroplasty jig blank with identifying information.

Abstract: A computer-implemented method of preoperatively planning a surgical procedure on a knee of a patient including determining femoral condyle vectors and tibial plateau vectors based on image data of the knee, the femoral condyle vectors and the tibial plateau vectors corresponding to motion vectors of the femoral condyles and the tibial plateau as they move relative to each other. The method may also include modifying a bone model representative of at least one of the femur and the tibia into a modified bone model based on the femoral condyle vectors and the tibial plateau vectors. And the method may further include determining coordinate locations for a resection of the modified bone model.