Apparatus, system, and method for determining a position of a hip prosthesis in a bone of a patient
An apparatus, system, and method for determining a position of a hip prosthesis in a bone of a patient includes determining a set of contact points between a femoral head of a femoral prosthesis and a cup liner of an acetabular cup to be implanted into a patient based on a mechanics model. The mechanics model is indicative of mechanical motion of a hip exhibited during performance of a set of ADL or at corresponding functional positions of the patient. In some embodiments, a mathematical model may be generated based on a plurality of sets of contact points determined using the mechanics model and subsequently used to determine a resultant set of contact points.
1 . A system for determining a position of a hip prosthesis in a patient, the hip prosthesis having a femoral prosthesis and an acetabular cup, the system comprising:
one or more processors; and
one or more memory communicatively coupled to the one or more processors and including instructions that, in response to execution by the one or more processors, cause the system to:
acquire a set of medical images of a hip of the patient;
determine pelvic tilt measurements of a pelvis of the patient based on the set of medical images, wherein the pelvic tilt measurements are indicative of a range of motion of the hip of the patient between different functional positions;
determine a set of contact points between a femoral head of the femoral prosthesis and a cup liner of the acetabular cup with a generic activities-of-daily-living (ADL) mechanics model, using a type and size of the femoral prosthesis and the acetabular cup, the pelvic tilt measurements, and an orientation of the acetabular cup relative to an acetabulum of the patient as inputs to the generic ADL mechanics model, wherein the generic ADL mechanics model is indicative of mechanical motion of a hip exhibited during performance of a set of ADL;
generate a contact plot based on the set of contact points, wherein the contact plot includes an indicia for each contact point in the set of contact points and for an edge of the cup liner;
receive a surgeon's selection of a planned orientation for the acetabular cup relative to the acetabulum of the patient in response to the contact plot; and
provide guidance to the surgeon to implant the acetabular cup in the acetabulum of the patient at the planned orientation selected by the surgeon.
2 . The system of claim 1 , wherein the set of medical images includes an anterior-posterior medical image of the hip of the patient while the patient is standing, a sagittal medical image of the hip of the patient while the patient is standing, a sagittal medical image of the hip of the patient while the patient is seated and fully bent over at the waist, and a sagittal medical image of the hip of the patient while the patient is standing with a contralateral leg in a flexed position and the back extended, and
wherein to determine the pelvic tilt measurements of the pelvis of the patient comprises to identify a plurality of anatomical landmarks of the hip of the patient based on the set of medical images.
3 . The system of claim 1 , wherein the plurality of instructions, in response to execution by the one or more processors, further cause the system to determine a pelvic mobility of the hip of the patient based on the pelvic tilt measurements,
wherein to determine the set of contact points comprises to determine the set of contact points with the generic ADL mechanics model using the type and size of the femoral prosthesis and the acetabular cup, the pelvic tilt measurements, the pelvic mobility, and the orientation of the acetabular cup as inputs to the generic ADL mechanics model.
4 . The system of claim 1 , wherein to determine the set of contact points comprises to:
determine a plurality of sets of contact points between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup with the generic ADL mechanics model using the type and size of the femoral prosthesis and the acetabular cup, a plurality of sets of pelvic tilt values, and a plurality of orientations of the acetabular cup relative to the acetabulum of the patient as inputs to the generic ADL mechanics model, wherein each set of contact points of the plurality of sets of contact points corresponds to (i) a different orientation of the acetabular cup of the plurality of orientations of the acetabular cup and (ii) a different set of pelvic tilt values of the plurality of sets of pelvic tilt values used as inputs to the generic ADL mechanics model; and
generate a mathematical model based on the plurality of sets of contact points, wherein the mathematical model is a model of the plurality of sets of contact points and is configured to produce a resultant set of contact points between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup using a set of pelvic tilt measurements as input, wherein to determine the set of contact points comprises to determine the set of contact points using the mathematical model with the pelvic tilt measurements as an input to the mathematical model.
5 . The system of claim 1 , wherein to determine the set of contact points comprises to determine a subset of contact points of the set of contact points for each ADL activity of the set of ADL, wherein the set of contact points comprises the subset of contact points for each corresponding ADL activity, wherein to determine the subset of contact points for each ADL activity comprises to:
temporally discretize each ADL activity into a plurality of temporal periods;
determine an angle between a femur of the patient and the acetabulum of the patient during each temporal period of the plurality of temporal periods based on the pelvic tilt measurements; and
determine a contact point between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup for each temporal period of the plurality of temporal periods with the generic ADL mechanics model using the type and size of the femoral prosthesis and the acetabular cup, the pelvic tilt measurements, the orientation of the acetabular cup, and the determined angle for the corresponding temporal period as inputs to the generic ADL mechanics model.
6 . The system of claim 1 , wherein the plurality of instructions, in response to execution by the one or more processors, further cause the system to determine an impingement-free range of motion of the femoral prosthesis and the acetabular cup based on (i) a three-dimensional model of the femoral prosthesis and a three-dimensional model of the acetabular cup and (ii) a plurality of orientations of the femoral prosthesis relative to a femur of the patient and a plurality of orientations of the acetabular cup relative to the acetabulum of the patient, and
wherein the plurality of instructions, in response to execution by the one or more processors, further cause the system to display the contact plot and indicia of the impingement-free range of motion.
7 . The system of claim 1 , wherein to determine the set of contact points comprises to determine a plurality of sets of contact points between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup with the generic ADL mechanics model, wherein each set of contact points of the plurality of sets of contact points corresponds to a different orientation of the acetabular cup relative to the acetabulum of the patient used as an input to the generic ADL mechanics model, and
wherein the plurality of instructions, in response to execution by the one or more processors, further cause the system to identify a sub-group of the plurality of sets of contact points that are predicted to result in edge loading of the acetabular cup based on a distance between at least one contact point of a corresponding set of contact points of the sub-group and the edge of the cup liner of the acetabular cup being within a reference threshold distance.
8 . The system of claim 7 , wherein the plurality of instructions, in response to execution by the one or more processors, further cause the system to:
determine an edge loading boundary based on the different orientations of the acetabular cup corresponding to the sub-group of the plurality of sets of contact points that are predicted to result in edge loading of the acetabular cup; and
display an indicia of the edge loading boundary.
9 . The system of claim 1 , wherein to determine the set of contact points comprises to determine a plurality of sets of contact points between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup with the generic ADL mechanics model, wherein each set of contact points of the plurality of sets of contact points corresponds to a different orientation of the acetabular cup relative to the acetabulum of the patient used as an input to the generic ADL mechanics model,
wherein the plurality of instructions, in response to execution by the one or more processors, further cause the system to:
determine a distance between at least one outermost contact point of each set of contact points and the edge of the cup liner of the acetabular cup; and
identify a preferred orientation of the acetabular cup based on the determined distances.
10 . A method for determining a position of a hip prosthesis in a patient, the hip prosthesis having a femoral prosthesis and an acetabular cup, the method comprising:
acquiring a set of medical images of a hip of the patient;
operating a computer system to determine pelvic tilt measurements of a pelvis of the patient based on the set of medical images, wherein the pelvic tilt measurements are indicative of a range of motion of the hip of the patient between different functional positions;
operating the computer system to determine a set of contact points between a femoral head of the femoral prosthesis and a cup liner of the acetabular cup with a generic activities-of-daily-living (ADL) mechanics model, using a type and size of the femoral prosthesis and the acetabular cup, the pelvic tilt measurements, and an orientation of the acetabular cup relative to an acetabulum of the patient as inputs to the generic ADL mechanics model, wherein the generic ADL mechanics model is indicative of mechanical motion of a patient-generic hip exhibited during performance of a set of ADL;
operating the computer system to generate a contact plot based on the set of contact points, wherein the contact plot includes an indicia for each contact point in the set of contact points and for an edge of the cup liner;
selecting a planned orientation for the acetabular cup relative to the acetabulum of the patient in response to the contact plot; and
implanting the acetabular cup in the acetabulum of the patient at the planned orientation.
11 . The method of claim 10 , further comprising operating the computer system to determine a pelvic mobility of the hip of the patient based on the pelvic tilt measurements,
wherein operating the computer system to determine the set of contact points comprises operating the computer system to determine the set of contact points with the generic ADL mechanics model using the type and size of the femoral prosthesis and the acetabular cup, the pelvic tilt measurements, the pelvic mobility, and the orientation of the acetabular cup as inputs to the generic ADL mechanics model.
12 . The method of claim 10 , wherein operating the computer system to determine the set of contact points comprises:
operating the computer system to determine a plurality of sets of contact points between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup with the generic ADL mechanics model using the type and size of the femoral prosthesis and the acetabular cup, a plurality of sets of pelvic tilt values, and a plurality of orientations of the acetabular cup relative to the acetabulum of the patient as inputs to the generic ADL mechanics model, wherein each set of contact points of the plurality of sets of contact points corresponds to (i) a different orientation of the acetabular cup of the plurality of orientations of the acetabular cup and (ii) a different set of pelvic tilt values of the plurality of sets of pelvic tilt values used as inputs to the generic ADL mechanics model; and
operating the computer system to generate a mathematical model based on the plurality of sets of contact points, wherein the mathematical model is a model of the plurality of sets of contact points and is configured to produce a resultant set of contact points between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup using a set of pelvic tilt measurements as input,
wherein operating the computer system to determine the set of contact points comprises operating the computer system to determine the set of contact points using the mathematical model with the pelvic tilt measurements as an input to the mathematical model.
13 . The method of claim 10 , wherein operating the computer system to determine the set of contact points comprises operating the computer system to determine a subset of contact points of the set of contact points for each ADL activity of the set of ADL, wherein the set of contact points comprises the subset of contact points for each corresponding ADL activity, and wherein operating the computer system to determine the subset of contact points for each ADL activity comprises:
operating the computer system to temporally discretize each ADL activity into a plurality of temporal periods;
operating the computer system to determine an angle between a femur of the patient and the acetabulum of the patient during each temporal period of the plurality of temporal periods based on the pelvic tilt measurements; and
operating the computer system to determine a contact point between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup for each temporal period of the plurality of temporal periods with the generic ADL mechanics model using the type and size of the femoral prosthesis and the acetabular cup, the pelvic tilt measurements, the orientation of the acetabular cup, and the determined angle for the corresponding temporal period as inputs to the generic ADL mechanics model.
14 . The method of claim 10 , further comprising operating the computer system to determine an impingement-free range of motion of the femoral prosthesis and the acetabular cup based on (i) a three-dimensional model of the femoral prosthesis and a three-dimensional model of the acetabular cup and (ii) a plurality of orientations of the femoral prosthesis relative to a femur of the patient and a plurality of orientations of the acetabular cup relative to the acetabulum of the patient, wherein the computer system causes the contact plot and indicia of the impingement-free range of motion to be displayed.
15 . The method of claim 10 , wherein operating the computer system to determine the set of contact points comprises operating the computer system to determine a plurality of sets of contact points between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup with the generic ADL mechanics model, wherein each set of contact points of the plurality of sets of contact points corresponds to a different orientation of the acetabular cup relative to the acetabulum of the patient used as an input to the generic ADL mechanics model, and
further comprising operating the computer system to identify a sub-group of the plurality of sets of contact points that are predicted to result in edge loading of the acetabular cup based on a distance between at least one contact point of a corresponding set of contact points of the sub-group and the edge of the cup liner of the acetabular cup being within a reference threshold distance.
16 . The method of claim 15 , further comprising operating the computer system to determine an edge loading boundary based on the different orientations of the acetabular cup corresponding to the sub-group of the plurality of sets of contact points that are predicted to result in edge loading of the acetabular cup, wherein the computer system causes an indicia of the edge loading boundary to be displayed.
17 . The method of claim 10 , wherein operating the computer system to determine the set of contact points comprises operating the computer system to determine a plurality of sets of contact points between the femoral head of the femoral prosthesis and the cup liner of the acetabular cup with the generic ADL mechanics model, wherein each set of contact points of the plurality of sets of contact points corresponds to a different orientation of the acetabular cup relative to the acetabulum of the patient used as an input to the generic ADL mechanics model, and further comprising:
operating computer system to determine a distance between at least one outermost contact point of each set of contact points and the edge of the cup liner of the acetabular cup; and
operating the computer system to identify a preferred orientation of the acetabular cup based on the determined distances.
18 . A method of performing an orthopaedic surgical procedure on a hip of a patient to implant a hip prosthesis having a femoral prosthesis and an acetabular cup, the method comprising:
operating a computer system to (i) determine a plurality of sets of contact points between a femoral head of the femoral prosthesis and a cup liner of the acetabular cup with a generic activities-of-daily-living (ADL) mechanics model, using a type and a size of the femoral prosthesis, a type and a size of the acetabular cup, pelvic tilt measurements of the patient, and a plurality of possible orientations of the acetabular cup relative to the acetabulum of the patient as inputs to the generic ADL mechanics model, wherein the generic ADL mechanics model is indicative of mechanical motion of a patient-generic hip exhibited during performance of a set of ADL, and wherein each set of contact points of the plurality of sets of contact points corresponds to a different possible orientation of the acetabular cup of the plurality of possible orientations of the acetabular cup used as an input to the generic ADL mechanics model and (ii) identify a sub-group of the plurality of sets of contact points that are predicted to result in edge loading of the acetabular cup based on a distance between at least one contact point of a corresponding set of contact points of the sub-group and an edge of the cup liner of the acetabular cup being within a reference threshold distance;
selecting a planned orientation for the acetabular cup relative to the acetabulum of the patient from among the plurality of possible orientations of the acetabular cup not corresponding to one of the sub-group of the plurality of sets of contact points that are predicted to result in edge loading of the acetabular cup; and
performing the orthopaedic surgical procedure on the hip of a patient to implant the acetabular cup in the acetabulum of the patient at the planned orientation.
19 . The method of claim 18 , wherein selecting the planned orientation for the acetabular cup is performed pre-operatively to the orthopaedic surgical procedure.
20 . The method of claim 18 , further comprising operating the computer system, during the orthopaedic surgical procedure, to (i) determine an actual orientation of the acetabular cup positioned in the acetabulum of the patient and (ii) display a contact plot including indicia for each contact point in one of the plurality of sets of contact points that corresponds with the actual orientation of the acetabular cup.