Method for manufacturing a patient-specific prosthesis for a fractured long bone

Patent metadata

Field	Value
Publication number	US-11266503-B2
Application number	US-201916268336-A
Country	US
Kind code	B2
Filing date	Feb 5, 2019
Priority date	Feb 6, 2018
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

The invention concerns a method for manufacturing a prosthesis (11) for a fractured long bone of a patient, the method comprising the steps of: A) providing data representative of the fractured long bone, the fractured long bone comprising a diaphyseal fragment (2) comprising a medullary cavity (8); B) based on said data, designing the prosthesis specifically to the patient, the prosthesis comprising a stem part (12) configured to be inserted into the medullary cavity, step B) comprising: a sub-step of choosing, specifically to the patient, a contact zone (40) of the medullary cavity onto which a respective chosen mechanical stress is planned to be applied by the stem part, and a sub-step of designing the stem part so that the stem part may be inserted into the medullary cavity and thus apply the chosen mechanical stress to said contact zone; and C) manufacturing the prosthesis designed at step B).

First claim

What is claimed is:

1. A method for manufacturing a prosthesis for a fractured long bone of a patient, the method comprising the steps of:
A) providing data representative of the fractured long bone of the patient, the fractured long bone comprising a diaphyseal fragment comprising a medullary cavity;
B) based on the data provided at step A), designing the prosthesis specifically to the patient, the prosthesis comprising a stem part configured to be inserted into the medullary cavity for securing the stem part to the diaphyseal fragment, step B) comprising:
a sub-step of choosing, specifically to the patient, at least one contact zone of the medullary cavity onto which a respective chosen mechanical stress is planned to be applied by the stem part, when the stem part is inserted into the medullary cavity and
a sub-step of designing the stem part so that the stem part may be inserted into the medullary cavity and thus apply the chosen mechanical stress to said at least one contact zone; and
C) manufacturing the prosthesis including the stem part designed at step B).

2. The method according to claim 1 , wherein said at least one contact zone of the medullary cavity continuously covers a circumference of the medullary cavity.

3. The method according to claim 1 , wherein during sub-step B1), the chosen mechanical stress is chosen to be evenly distributed onto each of said at least one contact zone of the medullary cavity.

4. The method according to claim 1 , wherein step B) comprises the further sub-step of, based on the data provided at step A), designing the stem part so that the stem part comprises, specifically to the patient:
a coverable diaphyseal portion, configured to be covered by the diaphyseal fragment when the stem part is secured to the diaphyseal fragment, whereas the rest of the stem part is left uncovered by the diaphyseal fragment; and
a first visible mark, visually delimiting the coverable diaphyseal portion from the rest of the stem part.

5. The method according to claim 1 , wherein:
step A) comprises providing data representative of epiphyseal fragments of the fractured long bone; and
step B) comprises, based on the data provided at step A), designing the prosthesis so that the stem part is configured for securing at least one of the epiphyseal fragments to the stem part.

6. The method according to claim 5 , wherein step B) comprises:
a sub-step of choosing, specifically to the patient, respective securing positions of the epiphyseal fragments relative to each other, representative of how the epiphyseal fragments are planned to be positioned relative to each other when secured to the stem part, the securing positions being chosen so that a respective chosen mechanical stress is applied onto each epiphyseal fragment by at least one of the other epiphyseal fragments, when the epiphyseal fragments are secured at the respective chosen securing positions of the stem part, and
a sub-step of designing the stem part so that the stem part is configured for securing the epiphyseal fragments at the respective chosen securing positions.

7. The method according to claim 6 , wherein step B) comprises the further sub-step of designing the stem part so that the stem part comprises a second visible mark indicating the respective securing positions of the epiphyseal fragments on the stem part.

8. The method according to claim 7 , wherein step B) comprises the further sub-step of designing the stem part based on the data provided at step A), so that the stem part comprises, specifically to the patient, coverable epiphyseal portions, being configured for being covered respectively by the epiphyseal fragments when the epiphyseal fragments are secured to the stem part at the respective securing positions; wherein the second visible mark is designed so as to visually delimit the coverable epiphyseal portions from each other.

9. The method according to claim 6 , wherein the stem part comprises, for at least one of the epiphyseal fragments, a respective plug, for securing the concerned epiphyseal fragment to the stem part, said at least one plug applying mechanical stress onto the epiphyseal fragment secured thereto.

10. The method according to claim 5 , wherein:
the epiphyseal fragments comprise:
at least one viable tuberosity fragment, secured to a muscle of the patient, the muscle being attached to said at least one viable tuberosity fragment by means of a tendon of the muscle and
a damaged articular fragment, initially being part of an damaged joint of the patient, for articulating the long bone with an auxiliary bone of the patient;
step B) comprises:
based on the data provided at step A), designing the prosthesis so that:
the stem part is configured for securing said at least one viable tuberosity fragment to the stem part, and
the prosthesis further comprises a head part, being configured to be secured to the stem part in replacement for the damaged articular fragment of the fractured long bone of the patient,
a sub-step of choosing, specifically to the patient, respective securing positions of said at least one viable tuberosity fragment and of the head part relative to each other, representative of how said at least one viable tuberosity fragment and head part are planned to be positioned relative to each other when secured to the stem part, the securing positions being chosen so that a respective chosen mechanical stress is applied to each of said at least one viable tuberosity fragment by the head part, when said at least one viable tuberosity fragment and the head part are secured at the respective chosen securing positions of the stem part, and
a sub-step of designing the stem part so that said at least one viable tuberosity fragment and the head part may be secured to the stem part at the respective chosen securing positions;
step C) comprises providing or manufacturing the head part of the prosthesis.

11. The method according to claim 10 , wherein the head part comprises:
a standard cap, comprising an articular surface of concave or convex shape for forming a prosthetic joint for replacement of the damaged joint of the patient, and comprising a securing surface opposed to the articular surface, the standard cap being secured to the stem part by means of the securing surface;
a patient-specific insert, designed during step B) patient specifically, and manufactured during step C), configured to:
be interposed between the standard cap and the stem part, and
apply the respective mechanical stress onto each of said at least one viable tuberosity fragment.

12. The method according to claim 1 , wherein step A) includes using CT scans of the patient and step C) includes additive manufacturing of at least a part of the prosthesis.

13. The method according to claim 1 , wherein the fractured long bone is a fractured humerus, the prosthesis being a shoulder prosthesis.

14. A patient-specific prosthesis for a fractured long bone of a particular patient, the prosthesis comprising a stem part that is designed based on data representative of the fractured long bone of this particular patient, so as to:
be inserted into the medullary cavity of a diaphyseal fragment of the fractured long bone of the patient for securing the stem part to the diaphyseal fragment, and
apply a chosen mechanical stress to at least one contact zone of the medullary cavity, chosen based on said data.

15. The patient-specific prosthesis according to claim 14 , wherein the stem part comprises, specifically to the patient:
a coverable diaphyseal portion, including at least a part of the stem part and being configured to be c

Assignees

• Howmedica Osteonics Corp

Inventors

• Coulange Vincent
• Courtade-Jouanicq Céline
• Gargac Shawn M
• Godelu Marine
• Rognin Guillaume

Classifications

• A61F2/4014 Primary

  Humeral heads or necks; Connections of endoprosthetic heads or necks to endoprosthetic humeral shafts · CPC title

• A61F2220/0016

  with sharp anchoring protrusions, e.g. barbs, pins, spikes · CPC title

• A61F2002/30948

  using computerized tomography, i.e. CT scans · CPC title

• A61F2002/30579

  with mechanically expandable devices, e.g. fixation devices · CPC title

• A61F2002/30556

  for adjusting thickness · CPC title