Patient-Specific Navigation Guides for Spinal Surgery

Abstract

A patient-specific navigation guide used in spinal surgery comprises a curved support frame having two arms, each having a patient-specific contact area, the support frame configured to abut against the respective contact area of ​​the patient's vertebra to define a unique joint configuration, and a main guide sleeve positioned on one side of the support frame and extending longitudinally between its proximal and distal ends, the main guide sleeve having a central hole that axially penetrates the longitudinal extension of the main guide sleeve itself for guiding surgical instruments into the patient's vertebra. The main guide sleeve has a patient-specific contact surface near its proximal end that abuts against the portion of the patient's vertebra being operated on in the joint configuration. The guide also comprises at least one reinforcing element positioned between the two arms, the reinforcing element having at least one central portion designed to cover the spinous process of the vertebra with or without contact. Furthermore, the guide comprises at least one bridge connecting element extending between the two arms, positioned between the contact area between the arm and the vertebra and the central portion of the reinforcing element covering the spinous process. The two arms consist of a support arm connected to the main guide sleeve and a mounting arm that does not have a connection to its own guide sleeve.

Description

Technical Field

[0001] The present invention relates to the technical field of orthopedic surgery.

[0002] More specifically, the present invention relates to a patient-specific navigation guide that can be used in spinal surgery.

[0003] A patient-specific guide is a disposable template, individually designed to match the bony anatomy obtained from computed tomography images of a specific patient. Surgical procedures such as drilling and incision can be planned preoperatively using computer-assisted technology, and the resulting patient-specific guide then allows a surgeon to accurately reproduce the planned procedure on the patient's body.

[0004] Patient-specific guides are used in various fields of orthopedics, including spinal surgery.

[0005] In this field, patient-specific guides are mainly used to assist surgeons during the insertion of pedicle screws, so that the screws can be inserted into the bone structure according to the pre-planned optimal insertion direction.

Background Art

[0006] Examples of patient-specific guides are known from patents EP2749235, EP2502582, US8758357, WO2014 / 090908, EP3863532, WO2013 / 158521, WO2014 / 197844, and also WO2014 / 070889.

[0007] As known in the prior art, a navigation guide comprises two or more tubular guide members integrated with a support frame.

[0008] The two tubular guide members define the insertion axes for the two pedicle screws, allowing them to be inserted into the patient's vertebrae at angles planned preoperatively. The insertion axes coincide with the longitudinal axes of the tubular guide members. Thus, the tubular guide members have axial through cavities from which surgical instruments can be inserted, for example, to prepare the pedicles for receiving the pedicle screws.

[0009] The guides currently used in such surgeries are quite large in size, comprise two or more tubular guide members, and need to act simultaneously on multiple parts of the same vertebra, or even on adjacent vertebrae.

[0010] In recent years, minimally invasive spinal surgery has become popular, so there is a tendency to minimize the size of the incision.

[0011] With currently known and used guides, the incision must be fairly extensive in order to widen the wound and insert the guide into the correct position.

[0012] When the incision is extensive, the surgery can no longer be defined as minimally invasive, and the patient's postoperative recovery period and surgical time are prolonged. Furthermore, if such an incision extends to particularly unstable skin areas, such as near the coccyx, wound healing becomes extremely difficult.

[0013] The objective of the present invention is to overcome the shortcomings of the prior art. In particular, the objective of the present invention is to propose a patient-specific navigation guide that is compact and can be used for any vertebra in minimally invasive surgery.

[0014] A further objective of the present invention is to provide a patient-specific navigation guide that allows for safe and accurate screw insertion, even in challenging trajectories, and even at different locations on the same side of the vertebra, without continuous radius control.

[0015] Another objective of the present invention is to provide a patient-specific navigation guide that can provide simplified positioning relative to the patient's bone structure in a stable and safe manner.

[0016] These and further objectives and benefits are achieved by the patient-specific navigation guide described in the attached claims and the patient-specific navigation kit described in claim 11. [Overview of the Initiative]

[0017] A first aspect of the present invention provides a patient-specific navigation guide for use in spinal surgery, the navigation guide comprising an arched support frame having two arms, each having a patient-specific contact area, and each contact area being configured to abut against the respective contact area of ​​the patient's vertebrae to define a unique joint arrangement.

[0018] The two arms comprise a support arm, which is connected to its own guide element, and a mounting arm, which is not connected to its own guide element.

[0019] There is a single main guide sleeve positioned on one side of the support frame and connected only to the support arm, extending longitudinally between its proximal and distal ends, and having a central hole that axially penetrates the longitudinal extension of the main guide sleeve itself in order to guide surgical instruments into the patient's vertebrae.

[0020] The main guide sleeve has a patient-specific contact surface near its proximal end that, in the joint configuration, abuts against the area of ​​the patient's vertebrae where the surgery is performed.

[0021] The guide also includes a reinforcing element, which is positioned between two arms and has at least one central portion designed to cover, with or without contact, the spinous process of the vertebra to be operated on.

[0022] Further, the guide comprises at least one bridge connecting element extending between the two arms, said bridge connecting element being arranged at a position between a contact area between the arm and a vertebra and a central portion of a reinforcing element covering the spinous process.

[0023] Preferably, the connecting element has an arcuate shape, with a concave surface oriented toward the guide itself. The connecting element projects transversely to a plane passing through the longitudinal axis of the arm of the support frame.

[0024] The reinforcing element has a substantially V-shaped structure, with a concave surface oriented toward the vertebra.

[0025] The guide further comprises at least one support leg projecting from one of the arms of the support frame to provide sagittal stability to the guide itself.

[0026] The support leg comprises a spherical tip adapted to fit into a depression of the vertebra.

[0027] Advantageously, the support leg projects from an arm that supports a main guide sleeve, which becomes more unstable due to stresses generated by the passage of a surgical instrument.

[0028] The guide comprises at least one auxiliary guide sleeve connected to a support arm of the support frame by a support body that extends projecting from the support arm transversely to a plane passing through the longitudinal axis of the arm of the support frame.

[0029] The auxiliary guide sleeve extends longitudinally between a proximal end and a distal end, the axis of which is inclined relative to the longitudinal axis of the main guide sleeve, and the auxiliary guide sleeve has a central bore axially penetrating the longitudinal extension of the auxiliary guide sleeve itself for guiding a surgical instrument to a patient's vertebra.

[0030] Advantageously, the guide comprises a plurality of auxiliary guide sleeves that are continuously aligned on the same support body and have longitudinal axes inclined relative to each other.

[0031] Preferably, the guide comprises a gripping element arranged at the top of the support frame, the gripping element being arrangeable above a central portion of the reinforcing element.

[0032] A second aspect of the present invention provides a patient-specific navigation guide kit comprising two navigation guides, wherein the first guide has a main guide sleeve associated with one arm of the support frame, and the second navigation guide has a guide sleeve associated with the other arm arranged on the opposite side of the support frame, such that the kit can act on both sides of the same vertebra. The two navigation guides each have a respective support arm connected to their respective main guide sleeve, and the support arms are located on opposite sides of each navigation guide. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The patient-specific navigation guide described and claimed is also illustrated in the following figures, which are exemplary and not exclusive. [Figure 1] It is a perspective view of a patient-specific navigation guide according to the present invention, the navigation guide being associated with a vertebra to be operated on and according to a first embodiment. [Figure 2] It is a perspective view of a specific navigation guide associated with a vertebra to be operated on and according to a second embodiment with technical modifications to the first embodiment. [Figure 3] It is a bottom view of the guide shown in Figure 1. [Figure 4] It is a front view of the guide shown in Figure 2. [Figure 5] It is a perspective view of a patient-specific navigation guide according to the present invention, the navigation guide being according to a third embodiment with technical modifications to the first embodiment, merely for illustrative purposes. [Figure 6] It is a second guide that, together with the guide shown in Figure 5, constitutes a kit according to a possible embodiment of the present invention, in particular according to the third embodiment. [Figure 7] Figure 5 is a view from below of the guide. [Figure 8] This is a top view of the guide shown in Figure 7. [Figure 9] This is a front view of a guide according to a fourth embodiment, given by the configuration of a technical modification incorporated into the first embodiment. [Figure 10] This is a top view of a guide according to a fourth embodiment of the present invention. [Figure 11] This is a front view of a guide according to a first embodiment of the present invention, which is in a usage configuration associated with a vertebra different from that shown in Figures 1 and 2. [Modes for carrying out the invention]

[0034] With respect to the attached drawings, 1 shows a patient-specific navigation guide according to a first aspect of the present invention.

[0035] Guide 1 comprises a support frame 2, which preferably has an inverted U-shape or inverted V-shape as shown in the accompanying drawings, and has two mounting arms 3. Each arm 3 has its own contact area 4, which is adapted according to a particular patient. In other words, each contact area 4 is configured to be placed on the respective contact area of ​​the patient's vertebrae 100 so as to define a unique joint arrangement that conforms to the patient's anatomical structure.

[0036] Thus, Guide 1 exhibits optimal stability by having two unfolding surfaces, each configured according to the anatomical structure of a specific patient, rather than discrete mounting points.

[0037] The two arms 3 are, in particular, the support arm 3' and the mounting arm 3''.

[0038] The support arm 3' is connected to other functional elements of the guide (e.g., the guide sleeve described below), while the mounting arm 3'' has no connection to other functional elements of the guide and at best is connected to a structural element, serving only as an additional mounting point on the vertebra, balancing and evenly distributing the forces applied to the guide itself by the surgeon. In other words, the mounting arm 3'' is not connected to any guide sleeve or other functional elements, and is connected only to other structural elements such as the support arm 3', and possibly to further mounting elements as described below, via the frame 2 or via the connecting element 8 described below.

[0039] Only one side of the support frame 2, i.e., one arm, specifically the side associated with the support arm 3', has the guide sleeve 5.

[0040] The other arm 3, i.e., the mounting arm 3'' opposite to the arm connected to the guide sleeve 5, is not connected to any other guide sleeve and therefore has no connection to its own guide element. This mounting arm 3'' has only a lower contact area 4 for resting on the patient's spine. Thus, in this structure, the guide sleeve 5 is positioned on only one side of the support frame 2 with respect to a plane perpendicular to the plane through which the two arms 3 pass.

[0041] The first arm 3 or support arm 3' is a support arm for further guide elements, such as the guide sleeve 5 described below, and this support arm 3' also has a mounting portion, i.e., a lower contact area 4, for guiding the vertebrae. The second arm 3 or mounting arm 3'', on the other hand, is simply a mounting arm and therefore has no connection to any guide sleeve or other guide elements.

[0042] The guide sleeve 5 extends longitudinally between its proximal end 5p and distal end 5d, and has a central hole 6 that axially penetrates the longitudinal extension of the sleeve 5 itself. This guide sleeve 5 is used to guide surgical instruments into the patient's vertebra 100.

[0043] The guide sleeve 5 also has a patient contact surface at its proximal end 5p that is specifically designed to contact the area of ​​the patient's vertebra 100 where the surgery is to be performed.

[0044] Between the two arms 3 of the support frame 2 is provided at least one reinforcing element 7, which has at least one central portion 7a intended to cover the spinous process 104 of the vertebra 100 being operated on, whether in contact or not. This reinforcing element 7 is preferably positioned directly below the support frame 2, and in particular below the upper part 2a of the support frame 2.

[0045] Preferably, the reinforcing element 7 has a substantially V-shaped structure with its concave surface oriented toward the vertebra.

[0046] Advantageously, the guide 1 also includes at least another structural element, such as a connecting element 8, preferably a bridge, that extends laterally to the two arms 3 to firmly connect the two arms 3. More preferably, the connecting element 8 is located between the contact area 4 between the vertebra 100 and the arm 3 and the central portion 7a of the reinforcing element 7 that covers the spinous process 104.

[0047] This connecting element 8 is therefore a crossing member, preferably not linear, that extends between the two arms 3, moving them apart and holding them firmly in predetermined relative positions.

[0048] Preferably, the connecting element 8 has an arcuate or inverted structure with respect to the spinous projection 104 it surrounds, with its concave surface oriented toward the guide itself. In other words, the connecting element 8 traverses a plane passing through the longitudinal axis 3a of the arm 3 of the support frame 2.

[0049] According to some embodiments, the connecting element 8 takes an arc shape and defines a sheet 88 within itself for accommodating the spinous process 104 of the vertebra 100.

[0050] The support frame 2 advantageously has at least one support leg 10 protruding from one side of the arm 3 to provide sagittal stability to the guide itself. Depending on the vertebra to be operated on, and therefore depending on the size of the guide used, there may be two support legs, one on each arm 3. The support legs 10 have contact surfaces with the vertebra that are formed according to a particular patient, i.e., formed to resemble the negative shape of the vertebra on which they rest, in order to obtain greater stability.

[0051] In some structures, preferably in some structures of guides specifically designed for sacral surgery, the support leg 10 has a spherical tip 11 (shown in Figures 2 and 4) that is fitted into a recess in the vertebra 100. Preferably, the support leg 10 always protrudes from at least the support arm 3 that supports the main guide sleeve 5, and the side with the sleeve is the side that is subjected to the most stress, as it is the side that the surgeon operates on.

[0052] According to some embodiments, as shown in Figure 5-8, the guide 1 also includes at least one auxiliary guide sleeve 12 that is always connected to the arm 3 supporting the main guide sleeve 5 and, by extension, to the support arm 3'. The auxiliary sleeve 12 is connected to the support arm 3' via a support 13 that protrudes from the arm laterally with respect to the plane through which the arm 3 of the support frame 2 passes. In this case, the support 13 functions as a support leg. To balance the structure, an additional support leg (and therefore considered a structural element rather than a functional element of the guide) can be provided associated with the free arm. In such a case, the leg 10 therefore protrudes from the support arm 3'', i.e., the free arm without the main guide sleeve 5 and the auxiliary guide sleeve 12, and balances the guide 1.

[0053] In certain structures, the main guide sleeve 5 and auxiliary sleeve 12 are all positioned on the same side of the guide and, in particular, all associated with the same support arm 3', making it possible to insert multiple screws on the same side of the vertebra. Therefore, the overall dimensions of the guide itself, and thus the size of the wound itself, can be significantly reduced.

[0054] The auxiliary guide sleeve 12 also extends longitudinally between its proximal end 12p and distal end 12d, with its axis 12a inclined with respect to the longitudinal axis 5a of the main guide sleeve 5. The auxiliary guide sleeve 12 also has a central hole 15 that axially penetrates the longitudinal extension of the auxiliary guide sleeve 12 itself in order to guide surgical instruments into the patient's vertebra 100.

[0055] Another embodiment (Figure 10) includes the presence of a plurality of auxiliary guide sleeves 12 that are arranged in a continuous alignment and have different inclination angles along their longitudinal axes, and are positioned on the same support 13 that protrudes from the support arm 3' associated with the main guide sleeve 5.

[0056] For example, other embodiments shown in Figures 9 and 10 include either a support leg or an auxiliary sleeve having a spherical tip. The spherical support 11 is positioned where a stronger grip on the vertebra is required for structural stability.

[0057] To facilitate handling, the support frame 2 is provided with a gripping element 16 substantially above the central portion 7a of the reinforcing element 7 connected to the spinous process 104 or the sacral crest, in its upper portion 2a. The gripping element 16 also functions as a pressure point for holding the guide in a stable position during insertion of surgical instruments into the guide channel.

[0058] Another aspect of the present invention is to propose a patient-specific navigation guide kit comprising two navigation guides as described above. Each guide comprises a main guide sleeve positioned on only one of two arms. Specifically, the kit consists of two guides, one of which has a guide sleeve (and an auxiliary sleeve, if any) on the right arm, and the other guide has a main guide sleeve (and an auxiliary sleeve, if any) on the left arm. In this way, it is possible to act alternately on both sides of the vertebra to be operated on at different times during surgery.

[0059] Therefore, each of the two navigation guides has its own support arm 3' connected to its own main guide sleeve 5. That is, the support arms 3' are positioned on opposite sides of each navigation guide.

[0060] Examples of such kits are shown in Figures 5 and 6, where Figure 5 shows a first guide with the main guide sleeve 5 on the left arm, and Figure 6 shows a second guide of the kit with the main guide sleeve 5 on the right arm.

[0061] The kits shown in Figures 5 and 6 are shown merely as examples, and the guide can be made according to any embodiment described and illustrated, namely, it is at least always a main sleeve (connected to only one support arm 3') and a main sleeve that can integrate a support leg, or one or more auxiliary sleeves (connected only to the same support arm 3'), or a combination of the two variations, namely a support leg and an auxiliary sleeve.

[0062] The guide according to the present invention has a small transverse dimension, which allows for easy use in minimally invasive surgery. The structure, with only one main sleeve on one side of the guide, connected to only one of the two arms, i.e., only the support arm, and with no additional guide elements on the other arm, allows for incisions of a more controlled dimension. The kit itself enables controlled cutting because it comprises two guides of the above type, each having a main sleeve associated with a single and different support arm.

[0063] Within the same incision, it is actually possible to insert a first guide, with the guide sleeve positioned on only one side, for example, on the right support arm. Once the guide is positioned and stable, the surgeon proceeds with the surgery. After acting on one side, the guide can be removed, and within the same incision, a second guide is inserted with the sleeve on the opposite side, for example, associated with the left support arm, thereby acting on the opposite side of the vertebra. Each guide has only a support arm, without connections to the guide sleeve or other elements adapted to act on the vertebra.

[0064] Compared to commonly used guides, the guide according to the present invention, i.e., the one-sided guide, has a more restrained profile and allows for easy insertion into an incision made in the patient without increasing the size of the patient's incision, especially for entry points where the screw trajectory is large. This is possible because the main guide sleeve and optionally the auxiliary sleeve are connected to only one arm, i.e., the support arm, while the other arm, i.e., the mounting arm, has no additional guide elements, and therefore the overall dimensions of the guide can be limited.

[0065] The guides that make up the kit are always manufactured in two versions: one for drilling on the left side and the other for drilling on the right side. In fact, the contact area of ​​the guide sleeve exists only on the side that is affected by the guide.

[0066] In all unilateral guides, stability is ensured by contact on both sides of the guide, allowing for safe and accurate screw insertion. The largest contact area is located on the side of interest or the side where the surgery is performed, as this is the side that is most stressed and prone to instability. A smaller contact area exists on the opposite side, ensuring good stability during use. [Prior art documents] [Patent Documents]

[0067] [Patent Document 1] EP2749235 [Patent Document 2] EP2502582 [Patent Document 3] US8758357 [Patent Document 4] WO2014 / 090908 [Patent Document 5] EP3863532 [Patent Document 6] WO2013 / 158521 [Patent Document 7] WO2014 / 197844 [Patent Document 8] WO2014 / 070889

Claims

1. A patient-specific navigation guide (1) used in spinal surgery, - A support frame (2) with a curved shape comprising two arms (3), each having a patient-specific contact area (4), wherein each contact area (4) is configured to abut against the respective contact area of ​​the patient's vertebrae (100) to define a specific bonding arrangement, and the two arms (3) comprise a support arm (3') connected to its own guide element and a mounting arm (3'') not connected to its own guide element, - A single main guide sleeve (5) positioned on one side of the support frame (2) and connected only to the support arm (3'), wherein the main guide sleeve (5) extends longitudinally between a proximal end (5p) and a distal end (5d), has a central hole (6) that axially penetrates the longitudinal extension of the main guide sleeve (5) itself for guiding surgical instruments to the patient's vertebra (100), and has a patient-specific contact surface near the proximal end (5p) that, in the combined configuration, abuts against the portion of the patient's vertebra (100) where surgery is performed, and - A reinforcing element (7) positioned between the two arms (3), comprising at least one central portion (7a) designed to cover the spinous process (104) of the vertebra (100) to be operated on, with or without contact, A patient-specific navigation guide (1) comprising: at least one bridge connecting element (8) extending between the two arms (3), the bridge connecting element (8) positioned between the contact area between the arms (3) and the vertebra (100) and the central portion (7a) of the reinforcing element (7) covering the spinous process.

2. The unique navigation guide (1) according to claim 1, wherein the connecting element (8) has an arc shape with a concave surface oriented toward the guide (1) itself, and the connecting element protrudes laterally with respect to a plane passing through the longitudinal axis of the arm (3) of the support frame (2).

3. The inherent navigation guide (1) according to claim 1, wherein the reinforcing element (7) has a substantially V-shaped structure with a concave surface oriented toward the vertebra (100).

4. The unique navigation guide (1) according to claim 1, comprising at least one support leg (10) protruding from one of the arms (3) of the support frame (3) in order to provide sagittal stability.

5. The specific navigation guide (1) according to claim 4, wherein the support leg (10) comprises a spherical tip (11) adapted to fit into a recess in the vertebra (100).

6. The support leg (10) protrudes from the support arm (3') of the main guide sleeve (5), wherein the unique navigation guide (1) is as described in claim 4.

7. The unique navigation guide (1) according to claim 1, comprising at least one auxiliary guide sleeve (12) connected to the support arm (3') of the support frame (2) by a support (13) extending from the support arm (3') in a direction laterally to a plane passing through the longitudinal axis of the arm (3) of the support frame (2).

8. The specific navigation guide (1) according to claim 7, wherein the auxiliary guide sleeve (12) extends longitudinally between a proximal end (12p) and a distal end (12d), the longitudinal axis (12a) is inclined with respect to the longitudinal axis (5a) of the main guide sleeve (5), and the auxiliary guide sleeve (12) has a central hole (15) that axially penetrates the longitudinal extension of the auxiliary guide sleeve (12) itself in order to guide surgical instruments into the patient's vertebra (100).

9. The unique navigation guide (1) according to claim 8, wherein there are a plurality of auxiliary guide sleeves (12) that are aligned in a continuous manner on the same support (13).

10. A unique navigation guide (1) according to any one of claims 1 to 9, comprising a gripping element (16) positioned on the upper part of the support frame (2), which can be positioned above the central part of the reinforcing element (7).

11. A patient-specific navigation guide kit comprising two navigation guides (1) according to any one of claims 1 to 10, wherein each of the two navigation guides (1) has a support arm (3') connected to its respective main guide sleeve (5), and the support arms (3') are positioned on opposite sides of each navigation guide.

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