	US 11,980,428 B2
	Method obtained by means of computer for checking the correct alignment of a hip prosthesis and a system for implementing said check
Francesco Siccardi, Castel San Pietro (CH); Massimiliano Bernardoni, Castel San Pietro (CH); and Daniele Ascani, Castel San Pietro (CH)
Assigned to Medacta International SA, Castel San Pietro (CH)
Appl. No. 17/602,215
Filed by MEDACTA INTERNATIONAL SA, Castel San Pietro (CH)
PCT Filed Apr. 6, 2020, PCT No. PCT/IB2020/053257 § 371(c)(1), (2) Date Oct. 7, 2021, PCT Pub. No. WO2020/208495, PCT Pub. Date Oct. 15, 2020.
Claims priority of application No. 102019000005350 (IT), filed on Apr. 8, 2019.
Prior Publication US 2022/0192755 A1, Jun. 23, 2022
Int. Cl. A61B 34/20 (2016.01); A61B 90/00 (2016.01); A61F 2/32 (2006.01); G06T 7/00 (2017.01); G06T 7/33 (2017.01); G06T 7/68 (2017.01); G06T 19/20 (2011.01)

CPC A61B 34/20 (2016.02) [A61F 2/32 (2013.01); G06T 7/0016 (2013.01); G06T 7/344 (2017.01); G06T 7/68 (2017.01); G06T 19/20 (2013.01); A61B 2034/2065 (2016.02); A61B 2090/364 (2016.02); G06T 2207/30008 (2013.01); G06T 2207/30052 (2013.01); G06T 2207/30168 (2013.01); G06T 2210/41 (2013.01); G06T 2219/2004 (2013.01)]

15 Claims

1. A method obtained by means of computer for checking correct alignment of a hip prosthesis, the method comprising:

acquiring a 3D model of a pelvic bone of a patient in a preoperative phase;

detecting at least one 2D image of the pelvic bone in post-implant situation;

selecting an image of the 3D model according to a first inclination thereof and detecting a reference element, represented by an acetabular cup, on said selected image of the 3D model;

identifying a plurality of reference points on the 2D image defining an ellipse given by a projection of an edge of the acetabular cup;

superimposing the 2D image on said selected image of the 3D model;

checking the correct superimposition and correspondence of the reference points of the 2D image with the reference element with said image of the 3D model;

generating a signal representative of a value of compliance to a predetermined superimposition criterion between the reference points of the 2D image and the reference element of the selected image of the 3D model;

if said predetermined compliance value is above a predetermined error threshold, modifying the inclination of the 3D model and repeating the above steps;

if said predetermined compliance value is below a predetermined error threshold, the image of the 3D model identified is correct and the superimposition and correspondence between the acetabular cup of the 3D model and the ellipse, given by the projection of the acetabular cup in 2D, is perfect, detecting possible differences in the positioning of the pelvic bone in post-implant configuration with respect to the preoperative situation as a function of the superimposition and correspondence of the reference points of the 2D image with the reference element of the image of the 3D model.