Patient-specific orthopedic implant evaluation

Patent metadata

Field	Value
Publication number	US-2025195143-A1
Application number	US-202318849807-A
Country	US
Kind code	A1
Filing date	Mar 22, 2023
Priority date	Apr 12, 2022
Publication date	Jun 19, 2025
Grant date	—

Abstract

A computer-implemented method of determining fixation of a prosthesis in bone matter based on bone anatomy and density information comprises generating a three-dimensional model of a bone of a patient for output in a video display unit, adding three-dimensional bone density information for the bone matter to the three-dimensional model, simulating a. preparation of the bone to produce a bone surface on the three-dimensional model, simulating placement of the prosthesis in the bone surface, estimating a fixation strength of the prosthesis to the bone matter using the bone density information at the prosthesis, and outputting indicia on the video display unit that indicates risk factors for displacement, of the prosthesis from the bone matter.

First claim

1 . A computer-implemented method of determining fixation of a prosthesis in bone matter based on bone anatomy and density information, the computer-implemented method comprising:
generating a three-dimensional model of a bone of a patient for output in a video display unit; adding three-dimensional bone density information for the bone matter to the three-dimensional model; simulating a preparation of the bone to produce a bone surface on the three-dimensional model; simulating placement of the prosthesis in the bone surface; estimating a fixation strength of the prosthesis to the bone matter using the three-dimensional bone density information at the prosthesis; and outputting indicia on the video display unit that indicates risk factors for displacement of the prosthesis from the bone matter.

2 . The computer-implemented method of claim 1 , wherein generating the three-dimensional model of the bone of the patient comprises aggregating a plurality of three-dimensional scans of the bone.

3 . The computer-implemented method of claim 1 , wherein generating the three-dimensional model of the bone of the patient comprises 2D to 3D generation using a plurality of two-dimensional x-ray images.

4 . The computer-implemented method of claim 1 , wherein generating the three-dimensional model of the bone of the patient comprises generating a finite element model.

5 . The computer-implemented method of claim 4 , wherein adding three-dimensional bone density information to the three-dimensional model comprises adding a number representing a grey value of each pixel of the finite element model.

6 . The computer-implemented method of claim 1 , wherein simulating placement of a prosthesis in the bone surface comprises:
displaying an outline of the prosthesis in the bone; and displaying an indication of bone density level at an intersection of the prosthesis with the outline.

7 . The computer-implemented method of claim 6 , further comprising:
simulating physical activity of a joint including the bone and the prosthesis; and simulating application of force on the prosthesis due to performance of the physical activity.

8 . The computer-implemented method of claim 7 , wherein:
simulating physical activity of a joint including the bone and the prosthesis comprises scaling force data according to patient-specific body information of the patient; and the force data is selected from a publicly available database of physical activities or a musculoskeletal model.

9 . (canceled)

10 . The computer-implemented method of claim 1 , wherein outputting indicia on the video display unit indicating risk factors for displacement of the prosthesis from the bone surface comprises:
displaying bone density indicators around the prosthesis in a heat map view in the three-dimensional model.

11 . The computer-implemented method of claim 1 , wherein outputting indicia on the video display unit indicating risk factors for displacement of the prosthesis from the bone surface comprises:
displaying a matrix of risk factors and implant conditions including an assessment of each risk factor at each implant condition.

12 . The computer-implemented method of claim 11 , wherein the assessment comprises an indication of whether or not a threshold for each risk factor has been met.

13 . The computer-implemented method of claim 11 , wherein the risk factors comprise one or more of loosening of the prosthesis, stress shielding of the bone around the prosthesis, dissociation of a component of the prosthesis from another component, bone fracture, implant fracture, bone removal, and cortex perforation.

14 . The computer-implemented method of claim 1 , further comprising:
changing an implant parameter; updating a simulated placement of the prosthesis; updating a risk factor estimate for the prosthesis; updating the indicia of risk factors based on changing of the implant parameter; and updating the indicia of risk factors in real-time in an operating room.

15 . (canceled)

16 . The computer-implemented method of claim 14 , wherein changing the implant parameter comprises changing the preparation of the bone surface or changing placement of the prosthesis in the bone surface.

17 . The computer-implemented method of claim 16 , wherein changing the implant parameter comprises changing a type of the prosthesis.

18 . The computer-implemented method of claim 1 , further comprising:
determining the indicia of risk factors comprises running an artificial intelligence engine to identify weakness in the three-dimensional bone anatomy and density information for the prosthesis; and updating the artificial intelligence engine with the identified weakness in the three-dimensional bone anatomy and density information.

19 . (canceled)

20 . The computer-implemented method of claim 18 , further comprising running the artificial intelligence engine to estimate the risk factor without simulating a resection and the placement of the prosthesis.

21 . A method of generating an electronic surgical plan using a patient-specific bone density model, the method comprising:
obtaining imaging of a bone of a patient including bone anatomy and bone density information of bone matter of the bone; generating a three-dimensional bone model of the bone of the patient from the imaging; determining bone density levels of the bone matter at three-dimensional locations in the three-dimensional bone model from bone density information of the imaging; plotting an interface for a prosthesis on the three-dimensional bone model; estimating fixation of the prosthesis to the bone at the interface due to engagement with the bone matter; and saving a digital version of the electronic surgical plan in a computer-readable storage medium, the electronic surgical plan including the prosthesis, the three-dimensional locations of the bone density levels, the interface and estimates of the fixation.

22 . The method of claim 21 , wherein estimating fixation of the prosthesis to the bone at the interface due to engagement with the bone matter comprises comparing the three-dimensional location of the bone density to three-dimensional locations of bone density levels of bones of a patient population, the method further comprising updating a database of surgical plans for a patient population with the digital version of the electronic surgical plan to train a machine learning algorithm.

23 . The method of claim 21 , wherein estimating fixation of the prosthesis to the bone at the interface due to engagement with the bone matter comprises solving equations of a finite element model defining the three-dimensional bone model.

24 . The method of claim 21 , further comprising:
comparing fixation levels of the prosthesis to the bone with threshold fixation levels to determine a probability of loosening of the prosthesis from bone; and displaying visual indicators of the threshold fixation levels on a video output unit; wherein the threshold fixation levels are determined for forces applied to the bone during performance of a specific activity.

25 . (canceled)

26 . The method of claim 24 , further comprising:
displaying the three-dimensional bone model on the video output unit; adjusting the interface for the prosthesis on the three-dimensional bone model in the video output unit or changing a fixation feature of the prosthesis that engages

Assignees

• Zimmer Inc

Inventors

• Favre Philippe
• Bischoff Jeffrey E
• Henderson Adam D
• Mueri Christine Mirja
• Maquer Ghislain
• Dharia Mehul
• Summers Rodney

Classifications

• A61B2034/108

  Computer aided selection or customisation of medical implants or cutting guides · CPC title

• A61B2034/105

  Modelling of the patient, e.g. for ligaments or bones · CPC title

• A61B2034/102

  Modelling of surgical devices, implants or prosthesis · CPC title

• A61F2/4059

  Humeral shafts · CPC title

• A61F2002/4633

  for selection of endoprosthetic joints or for pre-operative planning · CPC title