Measurement system and assembly for spinal surgery comprising such a measurement system

Abstract

The invention relates to a system for measuring a force in the context of spinal surgery, the measurement system comprising: - a pre-stressed force sensor (101) configured to measure a force applied by the longitudinal connecting implant (2), - a clamping device (102) configured to clamp the pre-stressed force sensor (101) in a pre-stressed configuration, - a cooperating element (104) configured to cooperate directly or indirectly with the longitudinal connecting implant (2), wherein the cooperating element (104) is configured to transmit the force to the pre-stressed force sensor (101).

Description

[0001] Title: Measurement system and assembly for spinal surgery comprising such a measurement system

[0002] FIELD OF INVENTION

[0003]

[0001] The present invention relates to a measurement system used in spinal surgery.

[0004]

[0002] More specifically, the present invention relates to a system for measuring a force exerted by an instrumentation on an anchoring implant and a longitudinal linking implant between the anchoring implants, in the context of spinal surgery.

[0005] TECHNOLOGICAL BACKGROUND

[0006]

[0003] The treatment of spinal disorders, such as degenerative diseases, fractures, scoliosis or other curvature abnormalities, often requires surgical treatments.

[0007]

[0004] Surgical treatment generally involves the use of longitudinal linkage implants, such as rods or plates. These longitudinal linkage implants can be fixed to at least two vertebrae to treat spinal disorders. In particular, longitudinal linkage implants can be used to align at least two vertebrae and / or to form a stable column for bone fusion or to absorb stresses that might be exerted on the vertebrae.

[0008]

[0005] Anchoring implants can be used to fix the stem to the vertebrae. In particular, these anchoring implants may include anchoring screws, such as pedicle screws, cables, links or sub-laminar bands, or hooks, including pedicle, transverse, or laminar hooks. The body of the anchoring implants is fixed in or around the vertebrae, while the head of the anchoring implants, which corresponds to the tulip-shaped end of an anchoring screw, emerges from the vertebra. The longitudinal connecting implant can then be inserted into the head of the anchoring implants. Locking elements can be used to permanently fix the longitudinal connecting implant in the head of the anchoring implant. These locking elements may include clips, a clamping screw, etc.

[0009]

[0006] When placing the longitudinal connection implant in an anchoring implant, it can be useful to control the force exerted on the longitudinal connection implant and the anchoring implant when it is placed in the anchoring implant. Indeed, excessive force could, for example, cause the anchoring implant to be pulled out of the vertebra, which would damage the vertebra.

[0007] Several systems for measuring the force exerted by a rod during spinal surgery have been developed.

[0010]

[0008] For example, document US11612420 describes a rod reducer comprising a sensor configured to measure torque at the instrument, and thus allow control of the force exerted by the rod during surgery.

[0011]

[0009] US patent 10893915 describes a clamping screw equipped with a sensor for measuring the force exerted by the rod. The clamping screw is intended to remain in the patient after surgery.

[0012]

[0010] Document U S2013 / 072,982 describes an orthopedic instrument for spinal surgery comprising a load gauge adapted to measure a force exerted by the rod.

[0013]

[0011] These documents do not, however, propose a measurement system that can be built at a controlled cost, allowing for reliable measurements and that can be at least partly disposable.

[0014]

[0012] The present invention aims to provide such a measurement system.

[0015] SUMMARY OF THE INVENTION

[0016]

[0013] Thus, the invention relates to a system for measuring the force exerted by a longitudinal connection implant during spinal surgery, spinal surgery involving:

[0017] - at least one anchoring implant, the anchoring implant comprising a body configured to be fixed onto or into a vertebra and a head configured to emerge out of the vertebra,

[0018] - at least one longitudinal link implant, said longitudinal link implant being configured to be received in the head of said at least one anchoring implant,

[0019] - at least one locking system, said at least one locking system being configured to permanently lock said at least one longitudinal link implant in said head of said at least one anchoring implant, the measurement system comprising:

[0020] - a prestressed force sensor configured to measure a force exerted by said longitudinal linkage implant on the prestressed force sensor,

[0021] - a clamping device configured to clamp said pre-stressed force sensor in a pre-stressed configuration,

[0022] - a cooperation element comprising a distal end configured to cooperate directly or indirectly with said longitudinal linking implant, and a proximal end opposite said distal end along a longitudinal axis of said cooperation element, said proximal end being configured to cooperate with an assembly formed by the clamping device and the prestressed force sensor, in which the cooperation element is configured to transmit the force exerted by the longitudinal linking implant to the clamping device, so as to enable said prestressed force sensor to measure said force.

[0023]

[0014] In general, the measurement system according to this application allows for spinal operations to be performed safely for the patient by means of integrating a pre-stressed force sensor that measures the force exerted by the longitudinal linkage implant during the operation. Indeed, during certain operations, the surgeon may not realize that the force exerted by the longitudinal linkage implant at the anchoring implant is too great, which can lead to the anchoring implant being pulled out of the vertebra, a vertebral fracture, or a vertebral deformity.By measuring in real time the force and stresses exerted on the longitudinal linkage implant, the pre-stressed force sensor not only allows the surgeon to adapt his actions to avoid these problems, but also informs him when the longitudinal linkage implant approaches or exceeds the limits of the elastic range, in order to prevent any entry into the plastic range.

[0024]

[0015] The measurement system described further ensures the accurate and reliable measurement of data thanks to the clamping device which pre-stresses the pre-stressed force sensor for the purpose of its calibration.

[0025]

[0016] Furthermore, the prestressed force sensor is advantageously a resistance prestressed force sensor. Thanks to this prestressed force sensor, the proposed measurement system can be produced at a controlled cost. This would therefore allow its deployment in numerous hospitals, thereby reducing the risks mentioned above that are associated with spinal surgery.

[0026]

[0017] Finally, this technology makes it possible to offer systems that would be at least partly single-use - and therefore disposable, reducing the risks related to hygiene with regard to the use of these systems in spinal surgery.

[0027]

[0018] In one configuration, the clamping device comprises a first and a second part clamping said prestressed force sensor, the clamping device further comprising a system for retaining the first and second parts, the retaining system being configured to keep said prestressed force sensor clamped between said first and second parts in the prestressing configuration of said prestressed force sensor.

[0028]

[0019] Advantageously, the clamping device is made of biocompatible material(s). The described clamping device allows for easy assembly of the instrument during its manufacture, which further reduces the operating costs of the measurement system. Moreover, the retention system for the first and second parts allows for continuous calibration of the prestressed force sensor. In other words, the clamping device ensures complete calibration of the prestressed force sensor once it is placed in said clamping device; i.e., the prestressed force sensor will theoretically no longer need to be recalibrated.

[0029]

[0020] In one configuration, the retaining system is a sleeve, configured to enclose said first and second parts.

[0030]

[0021] The use of such a sleeve minimizes the size of the clamping device, and therefore of the measuring system. Furthermore, the preload can be customized, increasing the accuracy of force measurements by the preloaded force sensor.

[0031]

[0022] In one configuration, the retaining system includes at least one screw configured to attach said first and second parts together.

[0032]

[0023] In one configuration, the force sensor is configured to be pre-stressed by

[0033]

[0024] applying a predetermined force to the force sensor, for example by means of a press,

[0034]

[0025] reading a value measured by the force sensor during the application of said predetermined force,

[0035]

[0026] progressively tightening the clamping device around the force sensor, until said value measured by the force sensor is reached during the application of said predetermined force.

[0036]

[0027] The predetermined force can be applied before the clamping device is positioned around the force sensor or, alternatively, can be applied when the clamping device is positioned around the pre-tensioned force sensor. In both cases, the clamping device is then progressively tightened around the force sensor to reach the same value as that measured by the pre-tensioned force sensor when the clamp is applied. Thus, while the clamping device is being tightened, the values ​​measured by the force sensor continue to be read.

[0037]

[0028] The described preload ensures the calibration of the force sensor and the reliability of the measurements performed by the preloaded force sensor once it is clamped in the preloaded position by the clamping device. Furthermore, commercially available force sensors may exhibit variations. For example, the positioning and / or shape of the ink pads used for measurement may differ from one force sensor to another due to machining. This preload therefore also ensures that each force sensor will be preloaded according to its own specific characteristics, which may vary from one force sensor to another.

[0038]

[0029] The embodiment in which the clamping device is pre-positioned around the force sensor during preloading is preferred because it allows for better consideration of the specific characteristics of the force sensor to be preloaded. Indeed, since the predetermined force is applied in the presence of the clamping device, the preloading is carried out taking into account the final configuration of the force sensor, i.e., clamped within the clamping device. Thus, the positioning of the ink pad within the clamping device is taken into account from the preloading stage, leading to greater accuracy in the measurements of the measuring system.

[0039]

[0030] The values ​​measured by the force sensor can be a resistance, a voltage and / or an impedance.

[0040]

[0031] Optionally, the positioning of the clamping device can be followed by a charge and discharge cycle and / or a calibration.

[0041]

[0032] By clamping the force sensor within the clamping device, the pre-stressed force sensor allows it to be compressed within the clamping device when a force is applied to it. A certain amount of play still exists between the pre-stressed force sensor and the clamping device. The pre-stressing helps to stabilize the ink evenly on the force sensor to ensure reliable measurements, while also allowing the pre-stressed force sensor to remain compressed within the clamping device, thus enabling it to perform force measurements.

[0042]

[0033] In one configuration, the system further includes a display device capable of displaying the data measured by the prestressed force sensor.

[0043]

[0034] Advantageously, the display device is a screen. The measurement system may further include means for communicating the preloaded force sensor with said display device. The communication means may be wired or may be wireless means, using Bluetooth, Wi-Fi, RFID, or other technology.

[0044]

[0035] In one configuration, the cooperation element is configured to perform a persuasion of the longitudinal link implant in the head of the anchor implant, the pre-stressed force sensor being configured to measure a force exerted by the longitudinal link implant during said persuasion.

[0045]

[0036] The measuring system thus makes it possible to measure the force exerted by the longitudinal linking implant during the persuasion of the stem towards the anchoring implant. This allows the surgeon to stop the procedure if the measured force is too great.

[0037] In one configuration, the distal end of the cooperation element is equipped with a locking system, the cooperation element being further capable of installing said locking system over said longitudinal linking implant when it is received in the head of the anchoring implant, the pre-stressed force sensor being configured to measure a force exerted by the longitudinal linking implant during the installation of the locking system over said longitudinal linking implant.

[0046]

[0038] The locking system can be a locking clip that is clipped around the head of the anchor screw and / or a locking screw that is screwed either into an opening in a locking clip or directly into a threaded opening in the locking screw. The measuring system thus advantageously allows the force exerted by the connecting implant during the installation of the locking system over the longitudinal connecting implant to be measured when it is received in the head of the anchor implant. Advantageously, the measuring system therefore allows both the persuasion of the longitudinal connecting implant and the placement of a locking system over the longitudinal connecting implant once the persuasion has been performed. This therefore reduces the number of instruments used during surgery.

[0047]

[0039] In one configuration, the system includes at least one handle configured to be mounted reversibly on the proximal end of the cooperation element, wherein the assembly comprising the clamping device and the pre-stressed force sensor is received in a handle of the system, said handle being configured to permit persuasion of the longitudinal link implant by actuating the cooperation element and / or installation of the locking system on the head of the anchor implant.

[0048]

[0040] Advantageously, the handle or part of the handle is for single use and is disposable.

[0049]

[0041] The handle is for example configured to drive the cooperation element in rotation around its longitudinal axis, causing, for example by means of a set of threads, a movement of the cooperation element towards the anchor implant, this movement allowing the rod to be pushed into the head of the anchor implant.

[0050]

[0042] The handle can be configured to allow the installation of the locking system, for example when said locking system is a locking screw.

[0051]

[0043] Advantageously, the measuring system comprises two separate handles, one adapted for gripping the longitudinal linkage implant and the other adapted for installing the locking system.

[0044] In one configuration, the cooperating element is mounted via a sliding connection in said instrument, such that said cooperating element is capable of performing a translational movement along its longitudinal axis and towards the assembly formed by the clamping device and the pre-stressed force sensor when a force is applied by the longitudinal linkage implant at the distal end of said cooperating element.

[0052]

[0045] This sliding joint assembly allows the forces received by the cooperation element to be transmitted to the clamping device, and thus to the prestressed force sensor which is clamped within the clamping device. The sliding joint also eliminates the need for contact between the prestressed force sensor and components used during surgery (such as the longitudinal connection implant, the anchoring implant, or the locking system), while ensuring accurate force data measurement.

[0053]

[0046] In particular, the translation can be induced during the persuasion of the longitudinal linkage implant, or when the locking system is installed. Persuasion of the longitudinal linkage implant can be carried out by moving the measuring system towards the longitudinal linkage implant, for example by pushing or screwing.

[0054]

[0047] In all the embodiments described here, the prestressed force sensor is advantageously not in direct contact with surgical elements (such as the longitudinal linkage implant, the locking system, the anchoring implant).

[0055]

[0048] In one configuration, the assembly formed by the clamping device and the prestressed force sensor is also mounted in the system according to a sliding connection, and in which, when the cooperation element is in translation towards the assembly formed by the clamping device and the prestressed force sensor, the proximal end of the cooperation element is configured to impart said translational movement to said assembly formed by the clamping device and the prestressed force sensor, until said assembly formed by the clamping device and the prestressed force sensor comes to rest against a wall.

[0056]

[0049] According to this configuration, the force exerted by the longitudinal connecting implant on the cooperation element (at its distal end) is directed to the prestressed force sensor in two stages. First, the force exerted by the longitudinal connecting implant is transmitted to the cooperation element at its distal end, causing a translational movement of the cooperation element towards the assembly formed by the clamping device and the prestressed force sensor. Then, when the proximal end of the cooperation element is in contact with said assembly, the translation of the cooperation element causes the translation of the clamping device and the prestressed force sensor until they reach a wall of the measuring system. When the clamping device reaches said wall, the prestressed force sensor is able to measure the force exerted by the wall of the system on said prestressed force sensor.This configuration therefore utilizes Newton's third law (law of action and reaction). This particular configuration allows, on the one hand, for easier manufacturing of the measuring system, as manufacturing tolerances can be higher, and on the other hand, for the prevention of friction that would cause elastic deformation of the cooperating element.

[0057]

[0050] In one configuration, the distal end of the cooperation element is configured to be received in said locking system of the longitudinal link implant in the anchor implant, and in that it is configured to be used when the longitudinal link implant is held, by the locking system, in the head of the anchor implant.

[0058]

[0051] The instrument is therefore configured to measure the forces exerted by the longitudinal link implant when it is held in the anchor implant by the locking system, after the longitudinal link implant has been persuaded into the head of the anchor implant.

[0059]

[0052] The force exerted by the longitudinal link implant corresponds to a pull-out force exerted by the longitudinal link implant on the anchoring implant. Indeed, during spinal surgery, a plurality of anchoring systems are placed in a plurality of vertebrae. The longitudinal link implant is designed to be received in each of the heads of the anchoring systems, for the purpose of straightening the spine, for example. Thus, in the non-limiting example where the longitudinal link implant is placed in a first anchoring implant, placing the longitudinal link implant in a second anchoring implant can generate a pull-out force at the first anchoring implant, related to the spinal deformation induced by placing the longitudinal link implant in the second anchoring implant.It is therefore particularly important to be able to control the values ​​of the force exerted by the longitudinal link implant throughout the operation, so that the surgeon can correct his maneuvers in real time to avoid any extraction of the anchor implant or trauma to vertebrae.

[0060]

[0053] Advantageously, the measuring system can be received in an opening of the locking system, the opening being provided so that the distal end of the cooperating element can be in contact with the longitudinal connecting implant received in the anchoring implant equipped with said locking system.

[0054] Advantageously, the measuring system is configured to be received reversibly in said locking system of the longitudinal connecting implant of the anchoring implant. In particular, the distal end of the cooperating element can be screwed into the locking system. Thus, the measuring system may include a threaded end, in particular its distal end, configured to be able to be screwed into a threaded opening of the locking system.

[0061]

[0055] Advantageously, the measuring system is received within the locking system of the longitudinal linkage implant throughout the operation. The measuring system is not configured to remain in the patient after the operation.

[0062]

[0056] The measuring system is advantageously single-use and can be discarded following the operation, in particular thanks to the technology of the prestressed resistance force sensor.

[0063]

[0057] In one configuration, it is intended to be received in an opening of a clamping screw, said clamping screw holding the longitudinal linking implant in the head of the anchoring implant.

[0064]

[0058] This configuration ensures that the longitudinal link implant is held securely in the head of the anchor implant when measurements are taken.

[0065]

[0059] In one configuration, the cooperation element includes a recess along its longitudinal axis and in that the assembly formed by the clamping device and the pre-stressed force sensor also includes a recess, the measuring system including a locking instrument configured to be received through said recesses, said cooperation element being configured to perform a persuasion of the rod in the head of the anchor implant, said locking instrument configured to install the locking system over the longitudinal link implant following the persuasion of the latter.

[0066]

[0060] According to this embodiment, the cooperation element is therefore hollow, and an opening is also provided in the clamping device and the pre-stressed force sensor. An instrument can thus be inserted into the cooperation element to allow for maneuvers during surgery without removing the measuring system, thereby enabling continued measurement of the forces exerted by the longitudinal connection implant. According to this embodiment, the cooperation element is not adapted to translate relative to the assembly formed by the pre-stressed force sensor and the clamping device. The forces exerted by the longitudinal connection implant are transmitted by means of a shoulder on the body of the cooperation element, against which the assembly formed by the pre-stressed force sensor and the clamping device bears. Thus, measurement systems without translation of the cooperation element can be provided.These measurement systems may nevertheless require more precise manufacturing, and therefore potentially more expensive, since the manufacturing tolerance during the assembly of the set formed by the prestressed force sensor and the clamping device on the cooperation element, in particular, must be minimal in order to obtain a reliable transmission of the forces exerted via the shoulder of the cooperation element, to the prestressed force sensor.

[0067]

[0061] In one configuration, the system further comprises a guiding instrument including lugs configured to be installed around the head of the anchoring implant, the lugs being further configured to be installed above the anchoring implant and said guiding instrument comprising a hollow body, wherein the hollow body of the guiding instrument is capable of guiding the cooperation element towards the longitudinal linking implant and / or the anchoring implant and / or the locking system.

[0068]

[0062] The guiding instrument therefore allows the cooperation element to be guided in the context of persuading the rod, installing the locking system following persuasion and / or installing the distal end of the cooperation element in the locking system.

[0069]

[0063] In one configuration, at least a portion of the interior of the hollow body of the guiding instrument includes a thread suitable for cooperating with a thread of the cooperating element, the screwing of said threads resulting in a relative movement of the cooperating element with respect to said guiding instrument, said movement allowing a progressive persuasion of the longitudinal connecting implant.

[0070]

[0064] In one configuration, it is configured to be positioned in the opening of the locking system by a persuasion instrument, said persuasion instrument being configured to persuade the longitudinal link implant and install a locking system over the longitudinal link implant when the latter is received in the head of the anchor implant, where the locking system is equipped with the measuring system during persuasion.

[0071]

[0065] Advantageously, the measuring system according to this embodiment is miniaturized and can be installed by a persuasion instrument. Advantageously, according to this embodiment, the persuasion instrument is equipped with a locking system with which it persuades the longitudinal link implant into the head of the anchor screw. The locking system is itself equipped with a measuring system such that the measuring system according to this embodiment can measure a force during persuasion and after persuasion, when the locking system is installed.

[0066] The present application also relates to an assembly for spinal surgery, the assembly comprising:

[0072] - at least one anchoring implant, the anchoring implant comprising a body configured to be fixed in a vertebra and a head configured to emerge out of the vertebra,

[0073] - at least one longitudinal link implant, said longitudinal link implant being configured to be received in the head of said at least one anchoring implant,

[0074] - at least one locking system, said at least one locking system being configured to permanently lock said at least one longitudinal link implant into said head of said at least one anchoring implant, the assembly comprising:

[0075] - a measurement system.

[0076] BRIEF DESCRIPTION OF THE DRAWINGS

[0077]

[0067] Embodiments of the invention will be described below with reference to the schematic drawings, briefly described below:

[0078]

[0068] [Fig. 1] Figure 1 illustrates a spine after surgery.

[0079]

[0069] [Fig. 2] Figure 2 illustrates a measuring system equipped with a locking system according to a first embodiment.

[0080]

[0070] [Fig. 3] Figure 3 is a view of the measuring system equipped with a locking system according to the first embodiment before the locking system is positioned on the rod.

[0081]

[0071] [Fig. 4] Figure 4 is a view of the measuring system equipped with a locking system according to the first embodiment when the locking system is positioned on the rod.

[0082]

[0072] [Fig. 5] Figure 5 is a view of a guiding instrument attached to an anchor screw and through which a rod is inserted.

[0083]

[0073] [Fig. 6] Figure 6 is a view of a measuring system according to a second embodiment before it is in contact with the rod.

[0084]

[0074] [Fig. 7] Figure 7 is a view of the measuring system according to the second embodiment when it is in contact with the rod.

[0085]

[0075] [Fig. 8] Figure 8 is a view of a measuring system according to a third embodiment before it is in contact with the rod.

[0086]

[0076] [Fig. 9] Figure 9 is a view of the measuring system according to the third embodiment when it is in contact with the rod.

[0087]

[0077] . [Fig. 10] Figure 10 is a view of a measuring system according to a fourth embodiment.

[0078] . [Fig. 11] Figure 11 is a view of the measuring system according to the fourth embodiment, when used with a guiding system.

[0088]

[0079] . [Fig. 12] Figure 12 is a view of a measuring system according to a fifth embodiment before it is in contact with the rod.

[0089]

[0080] . [Fig. 13] Figure 13 is a view of the measuring system according to the fifth embodiment when it is in contact with the rod.

[0090]

[0081] . [Fig. 14] Figure 14 is another view of the measuring system according to the fifth embodiment.

[0091]

[0082] [Fig. 15] Figure 15 is a partial view of a measuring system according to a sixth embodiment.

[0092] DETAILED DESCRIPTION

[0093]

[0083] Figure 1 illustrates a spine following spinal surgery according to an example of an embodiment.

[0094]

[0084] Figure 1 illustrates a plurality of vertebrae V, on each of which an anchoring implant 1 is fixed. The body of the anchoring implant 1 is located within the vertebra, while the head of the anchoring implant 1 emerges from the vertebra.

[0095]

[0085] A longitudinal linking implant 2 is positioned in the heads of the anchoring implants 1. The longitudinal linking implant 2 is locked in the heads of the anchoring implants 1 by means of a locking system 3. In Figure 1, the locking system 3 comprises a clip 31, the tabs of which grip the head of the anchoring implant 1. The clip 31 is drilled in its center and can thus receive a tightening screw 32. The clip 31 and the tightening screw 32 together form the locking system 3 of the longitudinal linking implant 2 in the anchoring implants 1.

[0096]

[0086] In another embodiment, the locking system does not include a clip. Only a clamping screw 5 is used to lock the longitudinal connecting implant 2 into the head of the anchoring implant. According to this embodiment, the clamping screw 5 is configured to be screwed directly into the head of the anchoring implant 1, over the longitudinal connecting implant 2.

[0097]

[0087] In the following description, the longitudinal connecting implant described is a rod, although the longitudinal connecting implant can take other forms, such as a plate. Similarly, the anchoring implant described is an anchor screw, although other types of anchoring implants can be used, such as hooks.

[0098]

[0088] During spinal surgery, the result of which is illustrated in Figure 1, different measurement systems can be used.

[0099]

[0089] Generally, a measuring system according to the invention makes it possible to measure a force exerted by the rod 2 during spinal surgery. The force exerted by the rod 2 includes a force exerted by the rod 2 during its insertion into an anchor screw head 1 and / or a force exerted by the rod 2 when it is received in the head of the anchor screw 1, before, during and / or after installation of the locking system.

[0100]

[0090] Preferably, the measuring system is configured to measure the pull-out force of the anchor screw when the rod is brought towards it. Thus, preferably, the force measured is that exerted when the rod 2 is brought towards the head of the anchor screw. A force can also be measured when the rod 2 is received in the head of the anchor screw. These measurements are particularly beneficial during surgery since they allow the extraction force to be controlled and adjusted as needed before the force becomes too great. Excessive extraction force could indeed lead to damage to the vertebrae, alteration of the surgical hardware, for example at the level of the anchor screw and / or the rod, or, in the most serious cases, the anchor screw being pulled out of the vertebra.

[0101]

[0091] Generally, the measurement systems described herein include a sensor 101 configured to measure the extraction force exerted during spinal surgery. Advantageously, the sensor 101 is a force sensor, and even more advantageously a resistance force sensor, better known by its abbreviation

[0102] "FSR sensor".

[0103]

[0092] This sensor has the advantage of being inexpensive, which makes it possible to obtain a measurement system that is at least partly disposable.

[0104]

[0093] The measuring systems further include a clamping device 102 for the sensor 101. The clamping device 102 allows the sensor 101 to be pre-stressed for calibration purposes. More specifically, the pre-stressing of the sensor 101 maintains the conductive element of the sensor 101 in a defined position. This optimizes the accuracy of the measurements performed by the sensor 101 and ensures the reproducibility of the results. Thus, the use of a pre-stressed force sensor ensures reliability and consistency in the measurements.

[0105]

[0094] The preloading is carried out before the sensor is installed in the measuring system. Once the sensor is preloaded, the assembly comprising the clamping device 102 and the preloaded sensor 101 can be installed in the measuring system.

[0106]

[0095] In one embodiment, preloading is performed by applying a force to the sensor. In one example, the force is applied using a press, exerting a predetermined force on the sensor, which serves as a reference force. For example, and without limitation, this value may be between 5% and 20% of the sensor's operating range, and preferably around 10% of the sensor's operating range. The sensor measures a value associated with the reference force. This value may be a resistance, a voltage, and / or an impedance of the sensor. The sensor is then left at rest for a period of between 24 and 48 hours.

[0107]

[0096] The clamping device is progressively tightened around the force sensor until the same resistance as that measured by the pressure on the sensor is reached. Once this value is reached, it is determined that the clamping device is correctly positioned around the sensor. The sensor is then considered to be correctly pre-stressed, and the assembly formed by the clamping device 102 and the sensor 101 can be installed in a measuring system.

[0108]

[0097] In a first embodiment, the clamping device can be positioned and tightened around the sensor after the force has been applied by the press and the rest period has elapsed. Alternatively, the clamping device can be placed around the sensor immediately after the reference force has been applied and the rest period has elapsed. This latter embodiment ensures that the point of contact will be identical at all times, thus further improving the measurement accuracy of the sensor.

[0109]

[0098] The prestressing allows, in particular, for the ink on the sensor to be fixed homogeneously, thus ensuring reproducibility of measurements throughout the sensor's service life. The prestressing also allows for consideration of the specific geometries of force sensors, which can vary from one sensor to another due to their mass production.

[0110]

[0099] The preloading can optionally be followed by a calibration step including, for example, load and discharge cycles of the sensor by applying the maximum force within its operating range. A calibration can also be performed, in which the force values ​​applied to the sensor are associated with a value measured by the sensor, for example, a voltage.

[0111]

[0100] When the sensor 101 is clamped by the clamping device 102, a gap exists between the clamping device 102 and the sensor 101, so as to allow the measurement of forces by the sensor 101 when it is clamped by the clamping device 102. More specifically, when a force is transmitted to the assembly formed by the sensor 101 and the clamping device 102, the sensor 101 remains able to compress according to its thickness, thus allowing the measurement of the force.

[0112]

[0101] When the sensor and clamping device assembly is mounted in the instrument, the sensor 101 is pre-stressed and calibrated, and theoretically requires no further recalibration. It is therefore particularly advantageous to offer a measurement system comprising the sensor 101 and the clamping device 102, since the measurement system thus provided ensures regularity, precision, and reproducibility in the measurements performed by the sensor 101 pre-stressed by the clamping device 102.

[0113]

[0102] According to one embodiment, a recalibration station may be provided in the operating room, in case an adjustment of the sensor calibration is required before and / or during the operation.

[0114]

[0103] In the following description, the term "sensor" or "force sensor" used is considered to refer to a prestressed force sensor.

[0115]

[0104] In one embodiment, the clamping device 102 may include a first and a second part 1021, 1022 intended to clamp the force sensor 101, in a configuration similar to a vise or a sandwich of the force sensor 101 between the first and second parts 1021, 1022 of the clamping device 102.

[0116]

[0105] A retaining system 1023 can further be provided to constrain the first and second parts 1021, 1022 in their clamping configuration of the sensor 101.

[0117]

[0106] For example, the retaining system 1023 may include screws and nuts holding the first and second parts 1021, 1022 together. In another example, the retaining system 1023 may take the form of a sleeve clamping the first and second parts 1021, 1022. Other configurations are possible. For example, rivets may be used, or the first and second parts may be crimped, or tension cables may be used, etc.

[0118]

[0107] The measurement systems also include a cooperation element 104.

[0119]

[0108] The cooperation element 104 is advantageously configured to cooperate directly or indirectly with the rod during the use of the measuring system. "Cooperation" means that the cooperation element 104 interacts passively or actively with the rod 2. The interaction may be an action exerted by the cooperation element 104 on the rod 2, as will be described in detail below. The interaction may also be a passive interaction of the cooperation element 104, which is simply in contact with the rod 2.

[0120]

[0109] By “direct” cooperation, it is understood that the cooperation element 104 can be in direct contact with the rod 2. By “indirect” cooperation, it is understood that the cooperation element 104 can interact with the rod 2 through another element.

[0121]

[0110] The cooperation element 104 is specifically intended to transmit to the sensor 101 the forces exerted by the rod 2.

[0111] Generally, the cooperation element 104 comprises a distal end 1041 and a proximal end 1042. The distal end 1041 is opposite the proximal end 1042 along a longitudinal axis of the cooperation element 104.

[0122]

[0112] The distal end 1041 is the end closest to the vertebrae when using the measuring system. The distal end 1041 is configured to cooperate directly or indirectly with the rod 2 when using the measuring system.

[0123]

[0113] The proximal end 1042 is the end closest to the user of the measuring system. The proximal end 1042 is configured to cooperate with the assembly formed by the clamping device 102 and the sensor 101.

[0124]

[0114] In certain embodiments, the cooperation element 104 can be mounted via a sliding connection relative to the assembly formed by the clamping device 102 and the sensor 101. In other words, the cooperation element can translate relative to the assembly formed by the clamping device 102 and the sensor 101. This configuration allows for ease of manufacturing since it does not require large tolerances during machining and assembly of the parts. In the rest position, i.e., when the cooperation element 104 is not cooperating directly or indirectly with the rod 2 or when the rod 2 is not exerting any force, the proximal end 1042 of the cooperation element is configured so as not to be in contact with the assembly formed by the clamping device 102 and the sensor 101. Thus, no force is transmitted to the sensor 101, which therefore does not measure any force.

[0125]

[0115] When the rod 2 exerts a force on the cooperation element, at its distal end 1041, the cooperation element 104 undergoes a translation so that its proximal end 1042 comes into contact with the assembly formed by the clamping device 102 and the sensor 101, thus transmitting the forces of the rod 2 to the sensor 101 which is able to measure a force exerted by the rod 2.

[0126]

[0116] In another configuration, the assembly formed by the clamping device 102 and the sensor 101 is also mounted in translation within the measuring system. Advantageously, the assembly formed by the clamping device 102 and the sensor 101 is configured to translate along the same axis of translation as the cooperation element 104. Thus, when the proximal end 1042 of the cooperation element comes into contact with the rod, the cooperation element 104 presses against the assembly formed by the clamping device 102 and the sensor 101 due to the forces exerted by the rod, the assembly formed by the clamping device 102 and the sensor 101 is configured to translate along the same translational movement until the clamping device abuts against a wall 1081 of the measuring system. The stop of the clamping device against the wall 1081 thus allows the sensor 101 to measure the forces exerted by the rod 2.

[0127]

[0117] Other embodiments are possible. In particular, the cooperation element 104 can be fixed relative to the assembly formed by the clamping device 102 and the sensor 101. In other words, the cooperation element 104 does not translate when its distal end is in contact with the rod 2. The distal end 1041 of the cooperation element 104 is in direct or indirect contact with the rod, and the proximal end 1042 of the cooperation element 104 is in contact with the assembly formed by the clamping device 102 and the prestressed sensor 101 throughout the entire clamping process. The forces are transmitted from the distal end to the proximal end of the cooperation element so that they can be measured by the force sensor.

[0128]

[0118] The measuring system further comprises an electronic system 107. The electronic system includes, in particular, a display device (not shown) for displaying the data read by the sensor 101. This display device can take any form, such as a screen, an indicator light, etc. The display device can be located directly on the measuring system or can be remote. In the latter case, a remote communication method can be provided, using, for example, Bluetooth, Wi-Fi, RFID, or other technologies.

[0129]

[0119] Figures 2 to 4 schematically illustrate a measurement system according to a first embodiment.

[0130]

[0120] Generally, according to this embodiment, the measuring system is used to persuade the rod 2, i.e. to push it, into the head of the anchor screw during surgery.

[0131]

[0121] The distal end 1041 of the cooperation element 104 of the measuring system according to this embodiment is adapted to grasp an element of the locking system 3. For example, the distal end 1041 of the cooperation element 104 is adapted to grasp the clip 31 and to position it on the head of the anchor screw 1 when the rod 2 is received in said head of the anchor screw 1. Alternatively, the distal end 1041 of the cooperation element 104 is adapted to grasp the clamping screw and position it on the anchor screw.

[0132]

[0122] The measuring system is advantageously designed to be used with a guide instrument 200. The guide instrument 200 is illustrated in Figure 5 in a position where it is attached to the head of the anchor screw and through which a rod 2 is inserted to be positioned in the head of the anchor screw 1.

[0133]

[0123] The guiding instrument 200, illustrated in Figure 5, comprises a hollow body intended to receive, in particular, the cooperation element 104. The hollow body of the guiding instrument 200 comprises, at its distal end, lugs 201 configured to be positioned around the head of the anchor screw. The rod 2 is configured to be inserted between the lugs 201 of the guiding instrument, as illustrated in Figure 5.

[0134]

[0124] The hollow body of the guiding instrument 200 guides the cooperating element, including the clip, to the head of the anchor screw. The distal end 1041 of the cooperating element 104 presses against the rod 2 to push it into the head of the anchor screw. Once pushed in, the cooperating element is able to install the locking system over the rod.

[0135]

[0125] To perform the persuasion and locking action, the interior of the hollow body of the guiding instrument 200 includes an internal threaded portion. The cooperating element is advantageously provided with a thread 105, corresponding to the threaded portion of the guiding instrument 200. The thread 105 is advantageously positioned around the cooperating element 104, towards its proximal end. The cooperating element 104 is able to translate relative to the thread 105. More precisely, when the cooperating element performs a translation as described above, the cooperating element also translates relative to the thread 105.

[0136]

[0126] When the cooperation element is inserted into the guiding instrument 200 until the threads of both are in contact, a handle 106 allows the threads to be screwed in, which allows the distal end 1041 of the cooperation element to gradually push the rod 2 towards the anchor screw, until it is received in the head of the anchor screw, then the locking system with which the distal end of the cooperation element 104 is equipped locks the rod 2 in the head of the anchor screw.

[0137]

[0127] As the cooperation element 104 is under tension by the rod 2, its proximal end 1042 is forced to come into contact with the assembly formed by the clamping device 102 and the sensor 101, thus allowing the sensor 101 to read the forces exerted by the rod. This configuration is illustrated in Figure 4.

[0138]

[0128] In other words, the rod 2, being forced by the cooperation element 104 towards the anchor screw, exerts a force towards the cooperation element 104. The cooperation element 104 then translates until its proximal end is in contact with the assembly formed by the clamping device 102 and the sensor 101, thus transmitting the forces to the sensor.

[0139]

[0129] The configuration in which the locking system, for example the clip 31, is not in contact with the rod 2 is illustrated in Figure 3. In this configuration, the proximal end 1042 of the cooperating element 104 does not transmit the forces from the rod to the sensor 101.

[0130] In the embodiment of the measuring system, illustrated in Figures 2 to 4, the clamping device comprises the two parts 1021, 1022 which are held together by a screw system 1023. As mentioned above, other embodiments are possible, and Figures 2 to 4 illustrate a non-limiting example.

[0140]

[0131] By way of example, the clamping device 102 is connected to the thread 105 of the measuring system by means of a screw system. The cooperating element 104 passes through the thread 105 and can thus translate relative to the thread 105 and to the assembly comprising the clamping device 102 and the sensor 101.

[0141]

[0132] Furthermore, the electronic system 107 is schematically illustrated in Figure 2.

[0142]

[0133] Figures 6 and 7 illustrate a measuring system according to another embodiment. In this embodiment, the measuring system is intended to be received in an element of the locking system 3 once this element locks the rod 2 in the head of the anchor screw 1. For example, the measuring system in this embodiment is configured to be received in an opening in the clip 31 of the locking system 3.

[0143]

[0134] Figures 8 and 9 illustrate an alternative embodiment of the embodiment shown in Figures 6 and 7. In the embodiment of Figures 8 and 9, the measuring system is intended to be received in an element of the locking system 3 once this element locks the rod 2 in the head of the anchor screw 1. For example, the measuring system in this embodiment is configured to be received in an opening of the clamping screw 32.

[0144]

[0135] Thus, the measuring system according to the embodiment of Figures 6 to 9 is configured to be used after the rod is locked in the head of the anchor screw, for example after the measuring system according to the first embodiment has constrained the rod in the head of the anchor screw and installed the locking system 3 locking the rod in the head of the anchor screw, i.e. the clip 31 and / or the clamping screw 32.

[0145]

[0136] Advantageously, the measuring system according to the second embodiment can be installed for the entire duration of the surgery. At the end of the surgery, the measuring system can simply be removed from the clamping screw hole without requiring any further action (Figures 8 and 9).

[0146]

[0137] In another configuration at the end of surgery, if the measuring system is received in an opening of the clip 31, the measuring system can be removed from said opening of the clip 31 to be replaced by the clamping screw (figures 6 and 7).

[0147]

[0138] The measuring system according to the second embodiment comprises the cooperation element 104, the clamping device 102, and the sensor 101.

[0139] With regard to the embodiments shown in Figures 6 to 9, and by way of example and not limitation, the clamping device 102 comprises the two parts 1021, 1022 clamping the sensor 101 in the preloaded position. The clamping device further comprises a retaining system 1023, in the form of a sleeve 1023 clamping the two parts 1021, 1022 and thus ensuring the preload of the sensor 101. Other embodiments are possible.

[0148]

[0140] The measuring system includes a body 108 for protecting the assembly formed by the clamping device 102 and the sensor 101. In a non-limiting example, the body 108 may be formed of two parts assembled by screwing. The body 108 further includes a threaded end 1082 for screwing the measuring system into the opening of the clamping screw and / or the opening of the clip, which openings of the clamping screw and / or the clip have a corresponding thread.

[0149]

[0141] The distal end 1041 of the cooperation element 104 protrudes out of the body in order to cooperate with the rod 2. More specifically, the distal end 1041 of the cooperation element 104 protrudes out of the threaded end 1082.

[0150]

[0142] When the cooperation element 104 is in contact with the rod 2, the force exerted by the rod 2 causes the cooperation element 104 to be translated towards the clamping device until the proximal end 1042 comes into contact with the assembly formed by the clamping device 102 and the sensor 101.

[0151]

[0143] In these embodiments, the translation of the cooperation element 104 causes the assembly formed by the clamping device 102 and the sensor 101 to move in the same direction. The assembly formed by the clamping device 102 and the sensor 101 then comes to rest against an internal wall 1081 of the body 108, which allows the transmission of the forces exerted by the rod 2 to the sensor 101. This configuration is illustrated in Figures 7 and 9.

[0152]

[0144] Advantageously, the assembly formed by the clamping device 102 and the sensor 101 is freely mounted in the body 108. Thus, when the body 108 is screwed into the clamping screw, the assembly formed by the clamping device 102 and the sensor 101 remains stationary while the body 108 rotates. This makes it particularly easy to screw the body into the opening of the locking system.

[0153]

[0145] Other embodiments are possible. In particular, the assembly formed by the clamping device 102 and the sensor 101 may not translate within the measuring system. The cooperation element 104, by its translation, can directly transmit the forces exerted by the rod to the assembly formed by the clamping device 102 and the sensor 101.

[0146] Figures 6 and 8 illustrate the configuration in which the cooperation element 104 is not in contact with the rod. It is visible in these figures that the assembly formed by the clamping device 102 and the sensor 101 is not in contact with the inner wall 1081 of the body 108, as no force is transmitted to this assembly by the cooperation element 104.

[0154]

[0147] The measuring system according to these embodiments can be installed on the locking system 3 by any means. For example, it can be screwed in by hand, or positioned using a persuasion-type instrument. In this configuration, a guiding instrument 200 can be used. The persuasion instrument then positions the measuring system by passing it through the hollow body of the guiding instrument.

[0155]

[0148] Figure 10 illustrates a measuring system according to a fourth embodiment. In this embodiment, the measuring system is configured to push the rod into the head of the anchor screw when used with a guiding instrument, i.e., to perform a persuasion of the rod 2. The measuring system according to this embodiment comprises a hollow body extending longitudinally between the distal and proximal ends, and a handle 106. The handle 106 is hollow in its center, as is the assembly formed by the clamping device 102 and the sensor 101, as well as the cooperation element 104.

[0156]

[0149] The cooperation element 104 includes a shoulder 111 at its proximal end 1042. The assembly formed by the clamping device 102 and the sensor 101 is mounted around the hollow body 109, between the shoulder 111 and the handle 106. In this embodiment, the cooperation element 104 is not configured to be in translation. The forces exerted by the rod are transmitted from the distal end 1041 to the shoulder 111.

[0157]

[0150] In use (see Figure 11), a guide instrument 200 is installed on the head of the anchor screw. In particular, the guide instrument 200 includes tabs 201 adapted to be reversibly secured around the head of the anchor screw. The rod 2 is also inserted between the tabs 201 of the guide instrument, without being received in the head of the anchor screw. The guide instrument 200 also includes a hollow body, into which the measuring system can be inserted. The distal end 1041 is configured to guide the rod 2 into the head of the anchor screw. To do this, the measuring system includes a threaded portion 105, located between the assembly formed by the clamping device 102 and the sensor 101, and the handle 106. The guiding instrument 200 also includes a corresponding threaded portion inside its hollow body.By turning the handle 106, the user matches the threaded portions, which causes the relative movement of the measuring system with respect to the guiding instrument 200. This causes the rod 2 to be driven towards the head of the anchor screw.

[0158]

[0151] During persuasion, the forces exerted by the rod 2 at the distal end of the cooperation element 104 of the measuring system are transmitted to the sensor by means of the shoulder 110.

[0159]

[0152] The hollow body of the cooperation element is configured to receive a locking instrument 300 as illustrated in Figure 11. The locking instrument 300 is configured to position the locking system 3 above the rod 2 once the rod has been driven into the head of the anchor screw by the measuring system. In particular, the locking instrument 300 can screw a locking screw into the head of the anchor screw by rotating it within the hollow body of the measuring system.

[0160]

[0153] Figures 12 to 14 illustrate a measuring system according to a fourth embodiment. The measuring system comprises a cooperation element 104, a positioning element of the locking system 115, a threaded body 112 and a handle 113.

[0161]

[0154] The cooperation element 104 comprises a longitudinal body extending longitudinally between a proximal end 1042 and a distal end 1041. The distal end 1041 of the cooperation element is configured to perform a persuasion of the rod 2.

[0162]

[0155] The cooperation element 104 comprises a first portion 1043 extending from the distal end 1041 of the cooperation element 104 and a second portion 1044 extending from the first portion to the proximal end 1042 of the cooperation element 104. The positioning element of the locking system 115 is configured to be positioned above the first portion 1043 of the cooperation element. The distal end 1041 of the cooperation element 104 remains accessible for persuasion. The positioning element of the locking system 115 is configured to be equipped with a locking system 3, such as a locking screw 3. The positioning element of the locking system

[0163] 115 is capable of translating relative to the cooperation element 104, as explained below. Furthermore, the measuring system includes a spring 114 positioned, in the longitudinal direction, between the positioning element of the locking system 115 and the second part 1044 of the cooperation element 104.

[0164]

[0156] Advantageously, when using the measuring system according to this embodiment, the positioning element of the locking system 115 is equipped with the locking system 3. The locking screw 3 is drilled in its center and is positioned around a distal end of said positioning element of the locking system 115. The distal end 1041 remains accessible at all times, so that it is the distal end 1041 that is in contact with the rod 2 and that persuades it, i.e., pushes the rod into the head of the anchor screw. This configuration prevents damage to the locking system 3 or the rod 2. When the distal end 1041 of the cooperating element 104 persuades the rod into the head of the anchor screw 1, the positioning element of the locking system 115 is held in place by the head of the anchor screw.As the persuasion continues to be exerted by the distal end 1041 of the cooperating element 104, the spring 114 is compressed. In other words, once the positioning element of the locking system 115 is in contact with the head of the anchor screw 1, the positioning element of the locking system 115 no longer moves and therefore remains static, blocked by the head of the anchor screw. The cooperating element continues the persuasion and thus translates relative to the head of the anchor screw and relative to the positioning element of the locking system 115, resulting in the compression of the spring. The compression of the spring 114 therefore allows, on the one hand, a progressive persuasion of the rod 2, and on the other hand, to maintain the positioning element of the locking system 115 against the head of the anchor screw until the rod 2 is completely received in the head of the anchor screw 1.

[0165]

[0157] The threaded tube 112 comprises a hollow body having a thread on its exterior. The threaded tube 112 is configured to be mounted around the cooperating element 104. More specifically, the threaded tube is configured to be mounted around the second part of the cooperating element 104. The threaded tube 112 further comprises a shoulder 1123. The shoulder 1123 is located substantially at a proximal end 1122 of the threaded tube 112.

[0166]

[0158] The external thread of the threaded tube 112 is configured to cooperate with a guide instrument 200. More specifically, the assembly comprising the cooperating element 104 and the threaded tube 112 is intended to be inserted into a guide instrument 200 at the time of the penetration of the rod 2. Thus, the guide instrument 200 includes tabs intended to grip around the head of the anchor screw. The rod 2 is also intended to be inserted between the legs of the guide 200. To drive the rod into the head of the anchor screw, the assembly formed by the cooperating element with the threaded guide 112 is inserted into the guide 200. The guide 200 has an internal thread corresponding to the thread of the threaded tube 112. A handle can be used to screw the threaded tube 112 into the guide 200.This screwing action causes a displacement of the assembly formed by the cooperation element 104 and the threaded tube 112 relative to the guiding instrument, this translation being directed towards the anchor screw. In this way, the distal end 1041 of the cooperation element 104 comes into contact with the rod 2 and persuades it until the rod 2 is received in the head of the anchor screw.

[0167]

[0159] The measuring system further includes a handle 113. The handle 113 is configured to be placed at the proximal end 1042 of the cooperation element 104. The handle includes at least one claw 1131, preferably at least two claws 1131 or three claws 1131, adapted to secure the handle 113 to the assembly formed by the threaded tube 112 and the cooperation element 104. More specifically, the claw 1131 is configured to grip the shoulder 1123 of the threaded tube 112.

[0168]

[0160] The claw 1131 is connected to a disengagement portion 1132. Pressing on the disengagement portion 1132 allows the claw to be lifted slightly relative to the shoulder 1123 in order to easily disengage the handle 113 from the threaded tube 112.

[0169]

[0161] When the handle 113 is fixed to the threaded tube by means of the claw 1131, the proximal end 1042 of the cooperation element is in contact with the assembly formed by the clamping device 102 and the pre-stressed sensor 101. Thus, the forces exerted by the rod during its persuasion, or when the rod is received in the head of the anchor screw, are transmitted to the sensor via the cooperation element.

[0170]

[0162] Advantageously, following the engagement of the rod 2 in the head of the anchor screw, the positioning element of the locking system 115 can install the locking system 3. As mentioned above, the locking system is, in this embodiment, a locking screw 3. The locking screw 3 is drilled in its center and is positioned around the positioning element of the locking system 115. The locking screw has, on its external surface, a thread corresponding to an internal thread of the head of the anchor screw 1. When the rod 2 is received in the head of the anchor screw, another handle can be mounted in place of the first handle described 113.The second handle (not shown) is positioned around the proximal end 1042 of the cooperation element 104 and can be rotated, so as to impart a rotational movement, around its longitudinal axis, to the cooperation element 104 and to the positioning element of the locking system 115. For example, the proximal end 1042 of the cooperation element includes a polygonal cross-section, and the handle includes a recess of corresponding shape.

[0171]

[0163] Figure 15 illustrates a sixth embodiment. In this embodiment, the clamping device 102 comprises a retaining block 1024, an intermediate piece 1045, and a clamping screw 1025. As shown in Figure 15, the sensor 101 is clamped between the retaining block 1024 and the intermediate piece 1045, the retaining block 1024 and the intermediate piece 1045 being held together around the sensor by means of the clamping screw 1025. More specifically, the retaining block 1024 includes a support wall 10241 against which the sensor 101 is positioned. A threaded hole 10242 extends from said support wall 10241. Said threaded hole 10242 is adapted to receive the clamping screw 1025. The clamping screw 1025 includes a recess in its center allowing the insertion of the intermediate piece. 1045.The intermediate piece has an upper end 10451 that is slightly wider than the recess for the clamping screw 1025 so that the clamping screw acts as a stop for the intermediate piece. The upper end 10451 also clamps the sensor. Thus, the intermediate piece 1045 is able to translate along the longitudinal axis of the measuring instrument, between a position in contact with the sensor 101 (or the concentrator 1011, see below) and the clamping screw 1025.

[0172]

[0164] During preloading, the clamping screw 1025 is screwed in until the desired force is obtained.

[0173]

[0165] In a preferred configuration, a concentrator 1011 can be bonded to the sensor 101. The concentrator 1011 allows for better distribution of forces and thus obtains more precise and reliable measurement data. Such a concentrator 1011 can also be used in the embodiments described above.

[0174]

[0166] When the cooperation element 104 is in contact with the rod 2, the force exerted by the rod 2 causes the cooperation element 104 to translate towards the clamping device 102, causing the intermediate part 1045 to translate towards the sensor (or concentrator) in order to obtain the measurement of the force exerted by the rod on the cooperation element 104.

Claims

1. DEMANDS

1. A system for measuring the force exerted by a longitudinal linkage implant (2) during spinal surgery, the spinal surgery involving: - at least one anchoring implant (1), the anchoring implant (1) comprising a body configured to be fixed on or in a vertebra and a head configured to emerge out of the vertebra, - at least one longitudinal linkage implant (2), said longitudinal linkage implant (2) being configured to be received in the head of said at least one anchoring implant (1), - at least one locking system (3), said at least one locking system (3) being configured to permanently lock said at least one longitudinal link implant (2) into said head of said at least one anchoring implant (1), the measuring system comprising: - a prestressed force sensor (101) configured to measure a force exerted by said longitudinal linkage implant (2) on the prestressed force sensor (101), - a clamping device (102) configured to clamp said pre-stressed force sensor (101) in a pre-stressed configuration, - a cooperation element (104) comprising a distal end (1041) configured to cooperate directly or indirectly with said longitudinal linking implant (2), and a proximal end (1042) opposite said distal end (1041) along a longitudinal axis of said cooperation element (104), said proximal end (1042) being configured to cooperate with an assembly formed by the clamping device (102) and the pre-stressed force sensor (101), in which the cooperation element (104) is configured to transmit the force exerted by the longitudinal linking implant (2) to the clamping device (102), so as to enable said pre-stressed force sensor (101) to measure said force.

2. Measurement system according to claim 1, wherein the clamping device (102) comprises a first and a second part clamping said pre-stressed force sensor (101), the clamping device (102) further comprising a retaining system (1023, 1025) of the first and second parts (1021, 1022, 1045, 1024), the retaining system (1023, 1025) being configured to hold said pre-stressed force sensor (101) clamped between said first and second parts (1021, 1022, 1024, 1025) in the pre-stressing configuration of said pre-stressed force sensor (101).

3. A measuring system according to the preceding claim, wherein the retaining system (1023) is a sleeve, configured to enclose said first and second parts (1021, 1022).

4. A measuring system according to claim 2 or 3, wherein the retaining system (1023, 1025) comprises at least one screw configured to attach together said first and second parts (1021, 1022).

5. A measuring system according to any one of the preceding claims, wherein the force sensor is configured to be pre-stressed by: applying a predetermined force on the force sensor, reading a value measured by the force sensor during the application of said predetermined force, progressively tightening the clamping device (102) around the force sensor, until said value measured by the force sensor during the application of said predetermined force is reached.

6. A measurement system according to any one of the preceding claims, further comprising a display device capable of displaying the data measured by the prestressed force sensor (101).

7. A measurement system according to any one of the preceding claims, characterized in that the cooperation element (104) is configured to perform a persuasion of the longitudinal link implant (2) in the head of the anchor implant (1), the pre-stressed force sensor (101) being configured to measure a force exerted by the longitudinal link implant (2) during said persuasion.

8. A measuring system according to any one of claims 1 to 7, wherein the distal end (1041) of the cooperation element (104) is provided with a locking system (3), the cooperation element (104) further being capable of installing said locking system (3) over said longitudinal linkage implant (2) when it is received in the head of the anchoring implant (1), the pre-stressed force sensor (101) being configured to measure a force exerted by the longitudinal linkage implant (2) during the installation of the locking system (3) over said longitudinal linkage implant (2).

9. A measuring system according to any one of claims 1 to 7, comprising at least one handle (113) configured to be mounted reversibly on the proximal end (1042) of the cooperating element (104), in which The assembly comprising the clamping device (102) and the pre-stressed force sensor (101) is received in a handle of the system, said handle being configured to allow persuasion of the longitudinal link implant (2) by actuating the cooperation element (104) and / or installation of the locking system (3) on the head of the anchor implant (1).

10. A measuring system according to any one of claims 1 to 8, wherein the cooperation element (104) is mounted by means of a sliding connection in said instrument, such that said cooperation element (104) is capable of performing a translational movement about its longitudinal axis and towards the assembly formed by the clamping device (102) and the pre-stressed force sensor (101) when a force is applied by the longitudinal connection implant (2) at the distal end (1041) of said cooperation element (104).

11. A measuring system according to the preceding claim, wherein the assembly formed by the clamping device (102) and the prestressed force sensor (101) is also mounted in the system by means of a sliding connection, and wherein, when the cooperation element (104) is in translation towards the assembly formed by the clamping device (102) and the prestressed force sensor (101), the proximal end (1042) of the cooperation element (104) is configured to impart said translational movement to said assembly formed by the clamping device (102) and the prestressed force sensor (101), until said assembly formed by the clamping device (102) and the prestressed force sensor (101) comes to rest against a wall.

12. A measuring system according to any one of claims 1 to 6 or 10 to 11, characterized in that the distal end (1041) of the cooperation element (104) is configured to be received in said locking system (3) of the longitudinal linking implant (2) in the anchoring implant (1), and in that it is configured to be used when the longitudinal linking implant (2) is held, by the locking system (3), in the head of the anchoring implant (1).

13. A measuring system according to the preceding claim, configured in that it is intended to be received in an opening of a clamping screw, said clamping screw maintaining the longitudinal linking implant (2) in the head of the anchoring implant (1).

14. A measuring system according to any one of claims 1 to 7, characterized in that the cooperation element (104) comprises a recess according to its longitudinal axis and in that the assembly formed by the clamping device (102) and the pre-stressed force sensor (101) also includes a recess, the measuring system comprising a locking instrument (300) configured to be received through said recesses, said cooperation element (104) being configured to perform a persuasion of the rod in the head of the anchor implant (1), said locking instrument configured to install the locking system (3) over the longitudinal link implant (2) following the persuasion of the latter.

15. A measuring system according to any one of the preceding claims, further comprising a guiding instrument (200) including lugs (201) configured to be installed around the head of the anchoring implant (1), the legs (201) being further configured to be installed above the anchor implant (1) and said guiding instrument (200) comprising a hollow body, suitable for guiding the cooperation element (104) towards the longitudinal link implant (2) and / or the anchor implant (1) and / or the locking system (3).

16. A measuring system according to the preceding claim, wherein at least a portion of the interior of the hollow body of the guiding instrument (200) comprises a thread suitable for cooperating with a thread of the cooperating element (104), the screwing of said threads causing a relative movement of the cooperating element (104) with respect to said guiding instrument, said movement allowing a progressive persuasion of the longitudinal connecting implant (2).

17. System according to any one of claims 12 or 13 and claim 15 or 16, characterized in that it is configured to be positioned in the opening of the locking system (3) by a persuasion instrument, said persuasion instrument being configured to push the locking system, equipped with said measuring system, through the guiding instrument until said locking system (3) equipped with the measuring system is positioned on the head of the anchor implant.

18. A system according to any one of the preceding claims, wherein a concentrator is attached to the sensor (101), wherein the cooperation element (104) is configured to transmit the force exerted by the longitudinal linkage implant (2) towards the clamping device (102), and more specifically towards the concentrator to improve the accuracy of the data measured by the sensor.

19. Kit for spinal surgery, the kit comprising: - at least one anchoring implant (1), the anchoring implant (1) comprising a body configured to be fixed within a vertebra and a head configured to emerge from the vertebra, - at least one longitudinal linkage implant (2), said longitudinal linkage implant (2) being configured to be received in the head of said at least one anchoring implant (1), - at least one locking system (3), said at least one locking system (3) being configured to permanently lock said at least one longitudinal link implant (2) into said head of said at least one anchor implant (1), the assembly comprising: - a measuring system according to any one of claims 1 to 17.

Images