LIMB POSITIONING SYSTEM

Abstract

A limb positioning system for positioning and maintaining immobilized a patient's limb in a desired position with respect to a surgical table during orthopedic surgery. The system includes: a pivoting member having a longitudinal portion extending along a corresponding longitudinal axis; a support member configured to support the patient's limb; the support member includes a support hooking part connected to the longitudinal portion and movable along the longitudinal portion; a clutch connected to the pivoting member having an open configuration and a locked configuration, wherein, in the open configuration, the clutch enables pivoting of the pivoting member around a rotation axis that is parallel to the longitudinal axis, distinct from the longitudinal axis, and wherein, in the locked configuration, the clutch allows immobilization of the pivoting member in the desired position; and at least one fixation member configured to maintain the system in position with respect to the surgical table.

Claims

1. A limb positioning system for positioning and maintaining immobilized a limb of a patient in a desired position with respect to a surgical table during orthopedic surgery, said system comprising: a pivoting member having a longitudinal portion extending along a corresponding longitudinal axis, said pivoting member being configured such that, when the system is in a normal use configuration, said longitudinal axis is parallel to the surgical table; a support member configured to support the limb of the patient; said support member comprises a support hooking part connected to said longitudinal portion and movable along said longitudinal portion; a clutch connected to the pivoting member having an open configuration and a locked configuration, wherein, in the open configuration, the clutch enables pivoting of the pivoting member around a rotation axis that is parallel to the longitudinal axis, distinct from the longitudinal axis, and wherein, in the locked configuration, the clutch allows immobilization of the pivoting member in the desired position; and at least one fixation member configured to maintain the system in position with respect to the surgical table.

2. The limb positioning system according to claim 1, wherein the pivoting member is movable relative to the clutch for varying a distance between the longitudinal axis and the rotation axis.

3. The limb positioning system according to claim 1, wherein the fixation member is configured to clamp the system to the surgical table.

4. The limb positioning system according to claim 3, wherein the fixation member is configured to clamp the system to a rail of the surgical table.

5. The limb positioning system according to claim 1, wherein the fixation member comprises a setting module configured to modify the position of the pivoting member, the support member and the clutch in a plane orthogonal to the rotation axis.

6. The limb positioning system according to claim 1, further comprising a weight compensation device configured to provide a weight compensation force to the pivoting member, said force being opposed to a weight of the limb applied to the pivoting member.

7. The limb positioning system according to claim 5, wherein the weight compensation device is a passive device or an active device such as an actuator.

8. The limb positioning system according to claim 7, wherein the passive device is a spring

9. The limb positioning system according to claim 7, wherein the active device is an actuator.

10. The limb positioning system according to claim 1, further comprising a bone grasping support having a first portion fixed to the pivoting member and comprising, at one end of a second portion, a grasping member configured to be rigidly fixed to at least one bone of the patient.

11. The limb positioning system according to 1, wherein the support member comprises an annular part configured to surround the limb, wherein the annular part is positioned with respect to the pivoting member so that the limb is hanged on the longitudinal portion of the pivoting member using the annular part.

12. The limb positioning system according to claim 11, wherein the support hooking part is detachably connected to the annular part so that the annular part is detachable from the longitudinal portion.

13. The limb positioning system according to claim 1, wherein the clutch is an electromagnetic power off brake.

14. The limb positioning system according to claim 1, further comprising a switching member for switching the clutch between the open configuration and locked configuration, said switching member being located below the rotation axis and at a predetermined distance from the floor when the system is in a normal use configuration.

15. The limb positioning system according to claim 11, wherein the switching member comprises two switches located respectively on both sides of the fixation member.

16. An assembly comprising a limb positioning system according to claim 1 and a surgical robotic device, wherein the limb positioning system and robotic device are connected to each other's.

17. The assembly according to claim 13, wherein the surgical robotic device comprises at least one movable member configured to pivot around a rotation axis coinciding with the rotation axis of the pivoting member of the limb positioning system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The following detailed description will be better understood when read in conjunction with the drawings. For the purpose of illustrating, the system and assembly is shown in the preferred embodiments. It should be understood, however that the application is not limited to the precise arrangements, structures, features, embodiments, and aspect shown. The drawings are not drawn to scale and are not intended to limit the scope of the claims to the embodiments depicted. Accordingly, it should be understood that where features mentioned in the appended claims are followed by reference signs, such signs are included solely for the purpose of enhancing the intelligibility of the claims and are in no way limiting on the scope of the claims.

[0034] Features and advantages of the invention will become apparent from the following description of embodiments of a system, this description being given merely by way of example and with reference to the appended drawings in which:

[0035] FIG. 1 is a perspective view of the system coupled to one leg of a patient according to an embodiment of the invention.

[0036] FIG. 2 is a top view of the system of the invention coupled to one leg of a patient.

[0037] FIG. 3 is a lateral view of the system of the invention coupled to one leg of a patient according to an embodiment of the invention.

[0038] FIG. 4 is a schematic representation of different positions in which the leg of the patient can be placed when using the system of the invention.

[0039] FIG. 5 is a schematic representation of the movements that may be permitted on the leg, when the system of the invention is coupled to one leg of a patient.

[0040] FIG. 6 is a schematic representation of the surgeon manipulating the leg of the patient when the system is in a locked configuration.

[0041] FIG. 7 is a perspective view of the system comprising a bone grasping support.

[0042] FIG. 8 is a perspective view of the assemble of the present invention.

[0043] While various embodiments have been described and illustrated, the detailed description is not to be construed as being limited hereto. Various modifications can be made to the embodiments by those skilled in the art without departing from the true spirit and scope of the disclosure as defined by the claims.

DETAILED DESCRIPTION

[0044] A limb positioning system 10 according to an embodiment of the present invention will now be described with reference to FIG. 1.

[0045] As shown in FIG. 1, the limb is a leg L of the patient and the positioning system 10 comprises a pivoting member 20, a support member 30 configured to support the limb of the patient, a clutch 40 connected to the pivoting member 20 and a fixation member 50.

[0046] In this first embodiment, the pivoting member 20 has a longitudinal first portion 21 extending along a corresponding longitudinal axis A.sub.L. The pivoting member is configured so as that, when the system is in a normal use configuration, the longitudinal axis A.sub.L always belong to a plane parallel to the surgical table T, no matter the position of the pivoting member 20 with respect to the table T. As shown in FIG. 1, the pivoting member 20 may comprise a second portion 22 that connects the longitudinal portion 21 to the clutch 40. In this example, the second portion 22 is substantially perpendicular or transversal to the longitudinal portion 21 and the longitudinal axis A.sub.L. The longitudinal axis A.sub.L extends in direction Z (FIG. 2).

[0047] Alternatively, the longitudinal portion 21 extending along a corresponding longitudinal axis A.sub.L may be directly connected to the clutch (not represented).

[0048] In order to set properly the pivoting member 20 towards the clutch 40, the second portion 22 can be adjusted by varying a distance between the longitudinal axis A.sub.L and the rotation axis A.sub.R. In one embodiment, multiple pivoting member 20 with a various length for the second portion 22 may be available to be coupled with the clutch. The surgeon will have to choose the length of the second portion according to the morphology of the patient.

[0049] Alternatively, the clutch 40 may be configured to receive a part of variating length of the second portion 22, the length of the part inserted into the clutch 40 being determined by the surgeon to fit the morphology of the patient.

[0050] In this embodiment, the support member 30 comprises a support hooking part 31 connected to said longitudinal portion 21 and a hanging element configured to receive and support the limb. Said hanging element is positioned with respect to the pivoting member so that, when the system is in a normal use configuration, the limb is hanged (or suspended) from the longitudinal portion of the pivoting member. As shown in the figures, the hanging element may be an annular part 32 configured to receive and support the limb, said annular part 32 being movably connected to the said longitudinal portion 21 through the support hooking part 31. The annular part 32 is connected to the support hooking part 31 so that when the limb is correctly placed into the annular part 32, said limb is hanged from the longitudinal portion 21 of the pivoting member 20. In the embodiment wherein the limb is a leg, the annular part 32 is configured to be fastened around the thigh of the patient. This is particularly advantageous since thanks to this configuration hanging the thigh, the area between the anterior part of the thigh, the calf and the surgical table is free from any obstacle, so that the surgeon performing a knee arthroplasty surgery can put the leg of the patient either in hyper flexion (i.e., calf in contact with the rear of the thigh), flexion or full extension (i.e., leg elongated laying on the table) with ease and without any disturbance. This embodiment also advantageously allows an easier take in hand of the limb by the surgeon as no component of the system prevents the surgeon to place his/her hands on any anterior part of the limb to lift it and perform the desired manipulation.

[0051] The annular part 32 may be a strip of fabric comprising fastening means allowing to close the strip into the annular shape, forming the annular part 32. Multiple fastening means, such as for example Velcro straps, may be positioned into both extremities of the strips in order to allow the strip to be closed into an annular part 32 so as to better adapt to the morphology of the patient. The annular part 32 may be an orthosis.

[0052] In this embodiment, the support hooking part 31 is movable along said longitudinal portion 21 so that the position of the support member 30 can be easily adjusted to each specific patient, and may be then clamped (not represented) to block the position of the support member 30 along the longitudinal axis A.sub.L

[0053] The support hooking part 31 may be detachably connected to the annular part 32 so that the annular part 32 hanging the limb may be detachable at any moment from the longitudinal portion 21. The support hooking part 31 may comprise a switch or a pushbutton that once pushed frees the annular part 32 from the support hooking part 31. This feature is particularly advantageous since it allows to quickly release the patient from the system in case of an emergency stop of the surgical procedure.

[0054] In this embodiment, the clutch 40 is a brake configured to reversibly switch between an open configuration and a locked configuration. In the open configuration, the clutch does not apply any force on the pivoting member 20 which is therefore free to turn around the rotation axis A.sub.R in both directions D1 and D2, the limit to this movement being imposed by the presence of the surgical table T when the system is in a normal use configuration and eventually by the presence of the limb L if the system is connected to the patient.

[0055] The clutch may be configured to allow the pivoting element to cover an angle range of 180 degrees when no patient is connected to the support element 30. When a leg of the patient is connected to the support element 30, the pivoting element 20 can cover, for example, an angle range of 20 to 90 degrees.

[0056] In the locked configuration, the brake of the clutch is activated and the pivoting member 20 is immobilized in a desired (angular) position so that the limb L of the patient is hanged in a desired position.

[0057] As shown in FIG. 1, when the system is adapted to support a leg, it does not comprise any support to fix the corresponding foot in a predefine position; the foot is simply placed on the surgical table at an adequate distance from the thigh. The surgeon may find the most suitable configuration of the leg for each step of the surgical procedure, being free to change said configuration at any moment.

[0058] In this embodiment, the system is maintained in position with respect to the surgical table T thanks to the fixation member 50. The fixation member 50 may be a monoblock or as a single piece, which therefore allows to fix the system in only one position with respect to the surgical table. Alternatively, the fixation member 50 may comprise a setting module allowing a fine tuning of the position of the system with respect to the surgical table T. This alternative will be described in details in association to FIG. 3.

[0059] FIG. 2, which provides a top view of the system of the invention, clearly shows that the rotation axis A.sub.R is parallel to the longitudinal axis A.sub.L. Furthermore, FIG. 2 shows as well the surgical table T and the rail R of the surgical table, which are not part of the system.

[0060] In this embodiment, the fixation member 50 is configured to clamp the system to the surgical table T. The fixation member 50 may be notably configured to be fixed on one rail R of the surgical table. The fixation member 50 may further comprise a setting module shown in FIG. 3.

[0061] FIG. 3 is a side view of the system 10. Notably, FIG. 3 is here used to describe the setting module which is configured to modify the position of the pivoting member 20, the support member 30 and the clutch 40 in a plane orthogonal to the rotation axis (A.sub.R). More in details, the setting module comprises a first platform 51 which is configured to modify the position of the system, once fixed on the surgical table, along a longitudinal direction X of the surgical table (i.e., horizontally with respect to the floor). This first platform 51 may be configured to be the portion of the fixation element that is able to clamp the system 10 to the surgical table T, for example by means of clips. The setting module comprises as well a second platform 52 configured to displace the system 10 along a vertical direction Y (i.e., a direction parallel to an axis perpendicular to the surgical table T plane). The second platform 52 may comprise a crank handle or be motorized in order to obtain the vertical displacement. The second platform 52 may be fixed onto the first platform 51, and be connected to the clutch 40. These X and Y settings will advantageously allow to align the rotation axis A.sub.R of the clutch 40 to the anatomic rotation center of the limb, more precisely, when the limb is a leg, to the hip center in the described example.

[0062] FIG. 3 shows as well that the clutch 40 may comprise an external housing 42 configured to comprise and protect from the external environment, the brake 41 and at least part of the weight compensation device 43.

[0063] The brake 41 may be electromagnetic brake, more precisely electromagnetic power-off brake, meaning that the brake is into its locked configuration when no electrical current flows through it. Advantageously, a permanent magnet inside said brake ensures that it remains in its locked configuration when no current flows through it.

[0064] Concerning the weight compensation device 43, it is configured to provide a weight compensation force to the pivoting member 20 supporting the limb. Said force is opposed to a weight of the limb, the weight being herein considered as a vector quantity representing the gravitational force acting on the limb. The weight (vector) may have a magnitude depending from a portion of the mass of the limb. Indeed, when the limb is a leg, the foot is usually positioned on the surgical table. This embodiment allows, when the clutch is in the open configuration, to advantageously assists a surgeon to lift the leg, during the positioning of the leg and the setup of the knee, as well as during soft tissue balancing manipulations.

[0065] The weight compensation device 43 may be a passive device, such as a spring-based mechanism, which exerts a restoring force whenever the spring is pulled or pushed by the pivoting member 20 which support the weight of the limb. Alternatively, the weight compensation device 43 may be an active device, such as an actuator connected to the pivoting member 20.

[0066] In this third embodiment, the system further comprises a switching member (60a, 60b) for switching the clutch between the open configuration and locked configuration. This switching member (60a, 60b) may be located below the rotation axis and at a predetermined distance from the floor when the system is in a normal use configuration so that the surgeon may push the switching member by applying a pressure with his/her knee. As shown in FIG. 3, the switching member comprises two switches 60a and 60b located respectively on both sides of the fixation member. In this example, each switching member 60a or 60b is activated by a substantially horizontal push (i.e. in a direction substantially parallel to the floor or the table T). Alternatively, the switching member may comprise a single switch (not represented) positioned on the external surface of the second platform 52 (i.e., the surface of the second platform 52 that is not facing the surgical table). The advantage of positioning the switching member at the height of the surgeon's knee is that he/she will be able to push the switch with a simple movement of his/her leg while using his/her arms to manipulate the limb of the patient.

[0067] Alternatively, the switching member for switching the clutch between the open configuration and locked configuration may be a simple pedal positioned on the floor. However, pushing the switch member with the knee or a part of the thigh (depending on the height of the surgeon) is easier and safer than searching with the feet for a switch disposed on the floor.

[0068] FIG. 4 shows a lateral view of the leg of the patient wherein the thigh is positioned inside the annular part 32 in different positions allowed by the system.

[0069] The leg may be disposed in an extension position E (FIG. 4) wherein the leg rests on the surgical table, not applying any force on the support member 30, and the clutch may be therefore in the unlocked configuration. Then, while the clutch is in the unlocked configuration, the surgeon may change the position of the leg to a flexion position F wherein the thigh and the calf forms an angle of less than 180 degrees. As shown in this FIG. 4, the support member 30 and the pivoting member 20 move with the thigh to which they are connected. To maintain the leg in this flexion position F, the clutch is switched to the locked configuration and the feet is positioned in an appropriate emplacement on the surgical table. As already explained above, the specific configuration of the support member 30 allows as well the surgeon to further push the calf against the thigh so as to reach the specific flexion position called hyper-flexion position H. As before, to pass from the flexion position to the hyper-flexion position, the clutch 40 had been switched into the open configuration and switched back to the locked configuration once the hyper-flexion position had been reached. The arrow F1 provide a visual representation of the movement of the pivoting element 20 and the thigh of the patient when changing from the extension position E to a flexion position (F, H) and inversely.

[0070] FIG. 5 provides a perspective view of the system, showing with the arrow F1 the pivoting movement of the thigh around the rotation axis. This pivoting movement is allowed by the support element 20 turning around the rotation axis when the clutch is in the open position. Arrows F2 and F3 represents the direction of displacement of the calf during manipulation of the leg by the surgeon (hands of the surgeon are represented manipulating the leg in FIG. 6), when the clutch is in the locked configuration.

[0071] FIG. 7 shows a configuration wherein the system 10 further comprises a bone grasping support 70 to rigidly fix a bone of the patient in a desired position. In this example, the bone grasping support 70 has a first portion 71 fixed to an end of the pivoting member 20 opposite to the clutch 40, and comprises a second portion 72 hinged connected to said first portion 71. The end of the second portion 72 opposite to the hinged connection comprises a grasping member 73 configured to be rigidly fixed to at least one bone of the patient. The first portion 71 extends here in a direction transversal to the longitudinal portion 21 of the pivoting member. The hinged connection may comprise a locking element that allows to block the hinged connection in a desired fixed position of the first portion 71 with respect to the second portion 72. This embodiment advantageously allows to first move the first portion 71 and the second portion 72 in order to adapt the bone grasping support 70 to the morphology of the patient, secondly to provide a rigid connection between the pivoting member 20 and the bone when the locking element blocks the first portion 71 and the second portion 72 in the desired fixed position. The grasping member 73 may comprises surgical screws allowing to fix the system for example to the tibia or femur of the patient. Such a bone grasping support 70 is well integrated in the system, thus resulting in a compact design and more room for the surgeon.

[0072] FIG. 8 shows an assembly comprising a limb positioning system 10 according to an embodiment of the invention, and a surgical robotic device 80, wherein the limb positioning system and robotic device are connected to each other's. In this example, the surgical robotic device 80 comprises at least one movable member 81 configured to pivot around a rotation axis coinciding with the rotation axis A.sub.R of the pivoting member of the limb positioning system. The robot and the positioning system may thus be referenced relative to a same axis, thus improving precision of the surgical robotic device. Moreover, when such an assembly is used in combination with the bone grasping device 70 (not represented), precision of the robotic device 80 is also improved due to the fixed position of the bone to which the device 70 is attached.