Method for simulating the behavior of an articulated set of bones
A method of simulating the behavior of an articulated set of bone parts, in particular the vertebral column comprising a construction step of constructing a three-dimensional geometrical model from data that is specific to the subject in a reference position; and a mechanical customization step of determining the geometrical model by detailing at least some of the connection areas of the bone parts. The mechanical customization step includes a stage of customizing critical connection areas for the bone parts; a data acquisition stage of acquiring data concerning the articulated bone set of the subject during at least one clinical test of posture; and a characterization stage for characterizing the mechanical parameters of said junction areas in order to cause the model to reproduce the data acquired during the above-mentioned clinical test.
1. A method of simulating the behavior of an articulated set of vertebrae of a spine, with limited computational capacity and time, comprising:
a construction step of constructing a three-dimensional geometrical model, in a computer, of the set from data that is specific to the subject in a reference position; and
a mechanical customization step of customizing the geometrical model comprising:
a stage of determining critical connection areas in the vertebrae set, by determining for every connection area the rotation and/or inclination of the adjacent vertebrae which are connected by this connection area;
concluding that every connection for which said rotation and/or inclination is singular are critical connection areas based on predetermined specific criteria;
concluding that every connection area for which said rotation and/or inclination is normal are not critical connection areas;
a data acquisition stage of acquiring data concerning the articulated vertebrae set of the subject during at least one clinical test of posture in a position different from the reference position or a clinical test of movement starting from said reference position; and
a stage of determination for the mechanical parameters of said critical connection areas in order to cause the model to reproduce the shape acquired by the above-mentioned set of vertebrae during the clinical test.
2. A method according to claim 1 , wherein it consists either in subjecting the model to a set of forces representing the action of an implant, or in combining the model in functional manner with an implant model depending on insertion strategy, in order to calculate the shape of the digital model that results therefrom and in order to represent it graphically.
3. A method according to claim 2 , wherein it consists in applying another set of static forces to the customized digital model, which other set of static forces represents supporting the subject during surgery and in removing said other set of static forces before representing the final result graphically.
4. A method according to claim 2 , wherein the set of forces belong to a database from Which they are extracted depending on the surgical method adopted and in said method, on the final operating strategy.
5. A method according to claim 4 , wherein the surgical method adopted is the method known by the name Cotrel-Dubousset.
6. A method according to claim 4 , wherein the method adopted is the in situ bending of the rod.
7. A method according to claim 3 , wherein the set of forces belong to a database from which they are extracted depending on the surgical method adopted and in said method, on the final operating strategy.
8. A method according to claim 7 , wherein the surgical method adopted is the method known by the name Cotrel-Dubousset.
9. A method according to claim 7 , wherein the method adopted is the in situ bending of the rod.