SCREW FIXATION METHOD

Abstract

A method for fixing a bone graft on a shoulder bone includes, before selection and use of a fixation device, a preoperative plan including collecting a preoperative imaging of a shoulder of a patient; virtually 3D modeling the shoulder; identifying at least one anatomical structure; and preoperative planning by one of sizing the graft, positioning the graft on the host bone, positioning the fixation device, and/or selecting the fixation device.

Claims

1. A method for fixing a bone graft on a shoulder bone, the method comprising, before selection and use of a fixation device, a preoperative plan including the following operations: collecting a preoperative imaging of a shoulder of a patient by radiography and/or ultrasound and/or CT image and/or MRI of the shoulder; virtually 3D modeling the shoulder; identifying at least one anatomical structure; and preoperative planning of at least one of the following operations: sizing the graft, positioning the graft on the host bone, positioning the fixation device, and selecting the fixation device.

2. The fixation method according to claim 1, wherein the method further comprises the following operations: displaying during surgical intervention the preoperative plan on an augmented or mixed reality device.

3. The fixation method according to claim 2, wherein the operations of displaying during the surgical intervention the preoperative plan on an augmented or mixed reality device comprises overlaying the preoperative plan onto a corresponding patient bone.

4. The fixation method according to claim 2, wherein the operations of displaying during the surgical intervention the preoperative plan on an augmented or mixed reality device comprises overlaying the preoperative plan onto a corresponding patient bone and guiding at least one of the following operations: sizing the graft, positioning the graft on the host bone, positioning the fixation device and selecting the fixation device.

5. The fixation method according to claim 1, wherein the fixation device is comprised of two screws and only two screws.

6. The fixation method according to claim 5, wherein at least one of the two screws comprises a cannula, where the at least one of the two screws is provided with a longitudinal through hole.

7. The fixation method according to claim 1, wherein the fixation device is comprised of two screws and only two screws, comprising: a first screw provided at a proximal end with a head for compressing a bone by an end-abutment; and a second screw provided at a distal end with a bone threading having a first helix pitch and at a proximal end with a bone threading having a helix with a pitch smaller than the first helix pitch, the second screw being headless.

8. The fixation method according to claim 7, wherein the method further comprises, after the preoperative planning step, using the first and second screws to position the bone graft on the host bone and fix the bone graft on the shoulder.

9. The fixation method according to claim 1, wherein the method further comprises, after the preoperative planning step, using the fixation device to position the bone graft on the host bone and fix the bone graft on the shoulder.

10. The fixation method according to claim 9, wherein the method further comprises the following operations: displaying during surgical intervention the preoperative plan on an augmented or mixed reality device.

11. The fixation method according to claim 10, wherein the operations of displaying during the surgical intervention the preoperative plan on an augmented or mixed reality device comprises overlaying the preoperative plan onto a corresponding patient bone.

12. The fixation method according to claim 10, wherein the operations of displaying during the surgical intervention the preoperative plan on an augmented or mixed reality device comprises overlaying the preoperative plan onto a corresponding patient bone and guiding at least one of the following operations: sizing the graft, positioning the graft on the host bone, positioning the fixation device and selecting the fixation device.

13. The fixation method according to claim 9, wherein the fixation device is comprised of two screws and only two screws.

14. The fixation method according to claim 13, wherein at least one of the two screws comprises a cannula, where the at least one of the two screws is provided with a longitudinal through hole.

15. The fixation method according to claim 9, wherein the fixation device is comprised of two screws and only two screws, comprising: a first screw provided at a proximal end with a head for compressing a bone by an end-abutment; and a second screw provided at a distal end with a bone threading having a first helix pitch and at a proximal end with a bone threading having a helix with a pitch smaller than the first helix pitch, the second screw being headless.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0083] FIG. 1 is an external side view of an embodiment of a first one of the two screws of the device of the invention;

[0084] FIG. 2 is a sectional side view of the screw of FIG. 1;

[0085] FIG. 3 is an external side view of an embodiment of the second one of the two screws of the device of the invention;

[0086] FIG. 4 is a sectional side view of the screw of FIG. 3;

[0087] FIG. 5 is a sectional view of an assembly of a bone graft to another bone.

[0088] FIG. 6 is a diagram of the main phases of the process leading to the selection and/or the creation of a kit and/or screws according to the invention specific to a patient.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0089] An embodiment of the device of the invention consists of the two illustrated screws.

[0090] The first screw 100 of FIGS. 1 and 2 comprises a head 110 and a rod 120. The head 110 comprises a recess 111 to cooperate with a setting tool (not illustrated) allowing the insertion of the screw into the bone. This first screw is pre-formed by a cannula 130.

[0091] The rod 120 is divided into several portions: [0092] A smooth proximal portion 121 disposed under the head 110, [0093] A conical proximal threaded portion 122 having a given pitch (single thread and disposed under the smooth proximal portion 121), [0094] A smooth middle portion 123, [0095] A distal threaded portion 124 having a pitch larger (double thread) than the pitch of the proximal portion 122.

[0096] The second screw 200 of FIGS. 3 and 4 is formed of a solid headless body which comprises [0097] A conical proximal threaded portion 210 having a given pitch (single thread) and a recess 211 to cooperate with a setting tool, [0098] A smooth middle portion 220, [0099] A distal threaded portion 230 having a pitch larger (double thread) than the pitch of the proximal portion 210.

[0100] As illustrated in the drawing of FIG. 5, the device is used for fixing the bone graft G to a host bone O. As illustrated, the screws are sized so that: [0101] the proximal threaded portions 122 and 210 cooperate only with the graft G; [0102] the distal threaded portions 124 and 230 cooperate only with the host bone O.

[0103] In addition, the length of the screws 100 and 200 is defined so that the distal threaded portions 124 and 230 of the screws pass through the cortical wall, of the host bone O, opposite the bone graft G.

[0104] Prior to the surgical intervention, during the phase of collecting data 310, the preoperative imaging of the patient to be operated is acquired in various ways. For example, radiographies and/or ultrasounds and/or CT images and/or MRI of the shoulder are used.

[0105] Based on the preoperative imaging of the patient to be operated, during a modeling and identification phase 320, at least one segmentation and treatment algorithm allows modeling the joint of the patient, identifying at least one anatomical structure. This phase may include the measurement of at least one specific feature of the joint of the patient.

[0106] During the planning phase 330, the surgeon performs a preoperative planning by means of a computer interface allowing to view the modeling of the joint and to perform at least one of the following operations: sizing the graft, positioning the graft on the host bone and positioning and selecting the screws constituting the fixation device according to the invention.

[0107] This method may further include the constitution, manufacture and provision for the surgical intervention of a patient-specific fixation kit produced based on the previously collected data and, particularly, on the planning output data.

[0108] It is understood that the device which has just been described and represented above, has been for the purpose of disclosure rather than limitation. Of course, various arrangements, modifications and improvements can be made to the example above, without departing from the scope of the invention.