MEDICAL DOUBLE JOINT STAB BENDING pliers

Description

Technical background

[0001] The present invention relates to a medical rod bending pliers with a first joint between handles and swivel arms with bending rollers.

[0002] In spinal surgery, pedicle screws are inserted into individual vertebrae and connected by a rod. This allows individual vertebrae that have slipped relative to other vertebrae, known as vertebral slippage, to be fixed in a desired position. The rod connecting the pedicle screws must be adapted to the shape of the individual patient's spine. It is known to use pliers to bend the rod. These pliers are also called rod bending pliers. Known rod bending pliers have two compressible handles (handle arms), two movable jaws with bending rollers at their free ends, and a joint / hinge between the handle pair and the bending rollers. Each handle arm is firmly connected to its corresponding jaw, preferably as a single piece (of fabric), thus forming a single component of the pliers.Both pliers components are not scissor-like but rather linked to each other via a hinge in a rocker-like fashion, such that when the handle jaws are squeezed together, the two jaw sections pivot apart. The bending rollers follow a circular path in the direction of the handle jaws.

[0003] The bar bending pliers also feature a central support surface (bending pin) located between the two bending rollers and extending towards the joint / hinge. When the handles are squeezed together, the bending rollers pivot around the joint / hinge, moving apart and backward towards the handles. When the bar rests against the central support surface, the circular movement of the bending rollers bends it around this surface. The bending radius of the bar depends on the geometry of the central support surface, while the bending angle (the measure of the bending motion) is primarily determined by the travel distance or radius of movement of the two bending rollers. This means that a larger travel distance of the bending rollers results in a larger bending angle. The bending radius at the bending point (which depends on the contact surface) remains unaffected by the bending angle (the angle of the bend).

[0004] Since the two bending rollers are mechanically coupled to the handles via the jaws, a large travel distance of the bending rollers simultaneously results in a large opening angle for both handles. Due to the necessary large opening angle of the handles / handle jaws, the rod bending pliers often have to be operated or held by a user or surgeon with two hands, similar to hedge shears. Because the user must also hold the rod in addition to the pliers, in practice, with known rod bending pliers, one hand is placed against the user's chest as a counter-support, the rod is held with one hand, and the other handle is operated with the other hand. This is not only unergonomic but can also contaminate or unsterile the rod bending pliers.

[0005] From US 2017 / 042 597 A1 and US 2023 / 355 289 A1, a bar bending pliers is known in which two handles are pivotable about a first joint and two pivot arms are movably connected to the respective handles by a second joint. The two pivot arms each rotate about a pulley. US 5 490 409 A discloses a bar bending pliers in which two handles are pivotable about a joint. Summary of the invention

[0006] The object of the present invention is to overcome or at least reduce the disadvantages of the prior art and, in particular, to provide a medical rod bending pliers that can be held and operated by a user with only one hand. Specifically, the user should be able to grip both handles of the rod bending pliers with one hand.

[0007] This problem is solved according to the invention by a medical rod bending pliers having the features of claim 1. Furthermore, the problem of the present invention is solved by a system having the features of claim 12.

[0008] Advantageous embodiments of the present invention are the subject of the attached dependent claims. Summary of Revelation

[0009] The basic idea of ​​the disclosure essentially consists of designing the rod bending pliers as double-jointed pliers and equipping them with a boom that is supported on the first joint / hinge (comparable to the rocker hinge of the prior art described above) of the double-jointed mechanism and extends towards a scissor hinge / connecting pin (in the longitudinal direction of the pliers) on which the (boomerang-shaped) jaw sections are coupled to each other in a scissor-like manner. The central bearing surface, also known from the prior art, is formed or mounted / can be mounted on the boom. The boom is further formed with a guide track, for example, a longitudinal slot, which is designed and configured to guide the scissor hinge / connecting pin longitudinally in the area of ​​the jaw sections.

[0010] More specifically, the present disclosure relates to a medical rod bending pliers withThe device consists of compressible handles or handle legs, (boomerang-shaped) swivel arms / branches / jaw sections that can be moved in opposite directions when the handles are moved, a deflector with a bearing surface prepared and designed so that the rod rests against the bearing surface and can be bent at the bearing surface, and a first (pivot) joint / hinge on which the handles are pivotally arranged relative to each other in the manner of a seesaw. That is, the first (pivot) joint / hinge is located in a front end region of the handle branches, such that a comparatively short handle extension projects beyond the first (pivot) joint / hinge towards the jaw sections.Each swivel arm / jaw section has a (rod) bending roller at its free end (facing away from the handle processes). This roller is movable with the respective swivel arm / jaw section and is designed and configured to bend a rod (of a spinal implant / pedicle screw) inserted into the rod bending pliers. The swivel arms / jaw sections are connected to each other in their central areas by a joint / connecting pin in a scissor-like manner and are hinged to the handle processes at their ends / end sections facing the handle processes by a second (rotary) joint / hinge.

[0011] The swivel arms are movably connected to each other by a connecting pin, which is mounted in a bore in each swivel arm. The connecting pin is movably mounted in a guide groove such that it has one degree of freedom in the direction of the longitudinal extension of the bar bending pliers.

[0012] The swivel arms can be connected to each other in a scissor-like manner, particularly by a connecting pin / bolt / connecting bolt. The two swivel arms can cross in their central section. Each swivel arm can have a central bore in which the connecting pin is mounted. The swivel arms are mounted to rotate or move about the connecting pin. The connecting pin can movably connect the two crossed central sections.

[0013] The swivel arms can be designed as flat, elongated plates, with the central bore for the connecting pin located in the central section of each swivel arm. The swivel arms can also be curved, forming a boomerang shape. Each swivel arm can have a proximal joint bore in its proximal end section, in which the joint pin of the second joint is mounted. The joint pin of the second joint can also be rotatably mounted in the second joint bore on the respective handle.

[0014] The movement of the swivel arms, and in particular their relative movement to each other, can have two components. Each swivel arm can perform a rotational movement around the second joint by which it is attached to the handle. Furthermore, a connecting section where the two swivel arms are joined can perform a translational movement along the longitudinal axis of the bar bending tool. That is, the connecting pin that joins the swivel arms can move axially along the longitudinal axis of the bar bending tool.

[0015] The rotational movement of the swivel arms can cause the distal end section, and thus the bending rollers, to move along a circular arc. When the rod is inserted into the rod bending pliers, the bending rollers can roll along the rod when the handles are actuated / squeezed. This movement along the circular arc, and thus the movement relative to the fixed rod, allows the bending rollers to bend the rod. Preferably, the bending rollers can therefore be prepared and configured to bend or plastically deform the rod of the spinal implant.

[0016] By moving the connecting pin in the direction of the longitudinal extension of the bar bending pliers, the translational movement of the connecting pin can be guided by the guide groove. The connecting pin can, in particular, have a wide pin head that is supported or guided in the guide groove. A longer pin cylinder of the connecting pin, protruding from the pin head, can be supported in the central bores of the swivel arms. The guide groove can thus limit the (translational) movement of the connecting pin, and consequently of the swivel arms, to one (translational) degree of freedom. This guided movement can result in a symmetrical / uniform movement of the two swivel arms.

[0017] In other words, the rod bending pliers have compressible handles (handle arms) or a compressible pair of handles that are pivotally arranged around the first joint / hinge of the double-joint mechanism in a rocker-like (i.e., not scissor-like) manner. Each handle arm has a (one-piece) handle extension that projects beyond the first joint / hinge towards the jaw sections of the pliers. Therefore, when the handles are compressed around the first joint of the double-joint mechanism, the free ends of the handle extensions move apart around the first joint. One of the two (boomerang-shaped) jaw sections is pivotally connected to each of the handle extensions via the second joint / hinge of the double-joint mechanism. The two jaw sections are scissor-like connected in their respective longitudinal midsections via the scissor joint / connecting pin.

[0018] Squeezing the handle pair together causes the handle extensions to move apart, along with the connected ends of the jaw sections. This, in turn, causes the free jaw section ends, and thus the bending rollers (due to the boomerang-like bend), to move in a circular motion towards the handle branches. This means the first joint remains static (stationary), while the handles perform a relative / pivoting movement around the first joint. The movement of the handles moves the pivoting arms / jaw sections, which are connected to the handles (movably / hinged). The connection between the pivoting arms and the handles constitutes the second joint. The movement of the scissor-like linked pivoting arms / jaw sections simultaneously moves the bending rollers attached to them.The bending rollers thus move towards the rod held at the contact surface relative to it, exerting a bending force on both sides of the contact surface, resulting in a rod bending movement. During this process, the bending rollers can roll along the rod and plastically deform it through their circular path.

[0019] Rod bending pliers are particularly useful as medical pliers for bending rods used in spinal implants. Bending allows the rod to be adapted to the anatomical shape of a patient, especially their spine.

[0020] The first joint can have a first joint pin, which is rotatably mounted in a first joint bore on the respective handle. The second joint can have a second joint pin, which is mounted in a second joint bore on the respective handle and in a further joint bore in the respective swivel arm.

[0021] The purpose of the disclosure is therefore to provide a (mechanical) transmission between the handles and the swivel arms / jaw parts with the bending rollers. This transmission can be achieved by designing the connection / coupling between the handles and the swivel arms as a double joint.

[0022] The disclosed bar bending pliers have the following advantages: The double joint allows the travel of the swivel arms, and thus the bending rollers, to be decoupled from the travel of the handles and therefore the opening angle of the handles. This allows the opening angle of the handles to be reduced without reducing the travel of the bending rollers. The handles can therefore be positioned so that a user can grip both handles with one hand, even when they are at their maximum distance from each other. Despite the reduced opening angle, the desired travel of the bending rollers can be maintained, thus ensuring the desired bending radius of the bar. The user can therefore hold and operate the bar bending pliers with one hand, leaving the other hand free to, for example, hold the bar being bent. This ensures an ergonomic and sterile working method for the user.

[0023] According to an optional feature of the present disclosure, the bending roller can be arranged on a distal end section of the respective pivot arm. The pivot arms can each have a proximal end section, a distal end section, and a central section located between the proximal and distal end sections. The bending roller can, in particular, be rotatably arranged on the distal end section and rotate about an axis of rotation that is preferably arranged perpendicular to a longitudinal extension of the bar bending tool.

[0024] A distal direction can be defined as pointing towards the bending rollers and a proximal direction as pointing towards the handles.

[0025] Preferably, the guide groove can be formed in a guide section / guide element / cantilever / support plate. The guide section can have a flat, plate-shaped base. A bore can be formed on a proximal side of the plate-shaped base in which the first pivot pin of the first joint is mounted. The guide section can thus be positioned by the first joint. The elongated guide groove can be formed on a distal side of the plate-shaped base. The depth of the guide groove can correspond to the thickness of the wide pin head of the connecting pin. The pin cylinder of the connecting pin can be guided in an elongated recess of the guide section. The plate-shaped base can, in particular, have the shape of a fork or a wrench.

[0026] The bar bending pliers have a deflection mechanism / handwheel / adjuster / actuator / adjustment device. The deflection mechanism can have a support surface or bending surface that is prepared and configured to rest against the bar and bend it. Together with the two bending rollers, the support surface can thus form (at least) three support surfaces or points on which the bar can rest. The deflection mechanism can be positioned between the bending rollers in the width direction of the bar bending pliers. That is, the deflection mechanism can be arranged on an axis of symmetry / longitudinal axis of the bar bending pliers, while the bending rollers are each offset outwards from the longitudinal axis. Thus, the bar can be bent around the support surface of the deflection mechanism by the relative movement of the two bending rollers. Therefore, the deflection mechanism can function as a deflection or support element.

[0027] Preferably, the deflector can be mounted on a receiving shaft of the guide section. The receiving shaft can be arranged on a guide section or project from it. In particular, the receiving shaft can be designed as a cylindrical attachment that projects perpendicularly from the plate-shaped base of the guide section. That is, the longitudinal axis of the receiving shaft can extend perpendicular to the longitudinal extent of the bar bending tool. The receiving shaft can be arranged centrally, especially when viewed in a longitudinal direction of the guide section. The guide section can thus serve as a support or support element for the deflector.

[0028] According to a further optional feature of the present disclosure, the deflector can be rotatably mounted about the receiving shaft. That is, the deflector can be rotatable about an axis of rotation that corresponds to the longitudinal axis of the receiving shaft.

[0029] Preferably, the deflector can be designed such that it is not rotationally symmetrical. In particular, depending on its orientation or direction of rotation, the deflector can form different support surfaces with varying contact areas or radii of curvature. The design of the support surfaces can influence the bending radius or a bending contour of the bar. In particular, the distance between the bending rollers and a vertex of the deflector's support surface, viewed along the longitudinal axis of the bar bending tool, can influence the bending of the bar. Since the vertex can also be varied by the curvature of the support surface, the bending of the bar can also depend on the curvature of the support surfaces.

[0030] Preferably, the deflector can be mounted to be axially movable or displaceable along the receiving shaft. This means the deflector can be moved perpendicular to the longitudinal axis of the bar bending tool. Thus, the deflector can have two degrees of freedom: one translational and one rotational degree of freedom. By moving along the receiving shaft, the deflector can be lifted from the guide section. By simultaneously lifting and rotating the deflector, particularly by the user, it can be turned into different positions.

[0031] The deflector can be designed, in particular, as a round rotary knob. The deflector can be designed such that an edge or gripping section of the deflector is accessible to the user. The user can thus rotate the deflector around its axis of rotation as well as slide it along the receiving shaft.

[0032] According to a further optional feature of the present disclosure, a spring can be provided between the deflector and the receiving shaft, the spring force of which acts in the axial direction of the receiving shaft. The spring can preferably be attached to a projection of the receiving shaft. When the user pulls or lifts the deflector away from the guide section, the spring is compressed. When the user releases the deflector, it is pushed back towards the guide section by the spring force. The spring can, for example, be a coil spring.

[0033] The protrusion of the receiving shaft can be caused in particular by a protruding cap / shaft end cap on the shaft or a (protruding) shaft end cap. The protrusion can also prevent the deflector from being guided away from the receiving shaft.

[0034] Preferably, the guide section can have a projecting pin that engages in corresponding (locking) receptacles of the deflector, depending on its orientation. Preferably, the deflector can have three receptacles. This allows the deflector to be locked or secured in three different orientations. In each of these different orientations, a different bearing surface can point distally, i.e., towards the bending rollers. The projecting pin can preferably be located next to the receiving shaft.

[0035] The receptacles on the deflector can be designed, in particular, as a contact surface on the deflector, where the deflector rests on the guide section. Furthermore, the deflector can be rotated into a cleaning position. In this position, the pin rests on the deflector's contact surface in such a way that the deflector is separated from the guide section by the pin. This means the user can lift the deflector from the guide section and rotate it around its axis of rotation until the pin rests on the contact surface. Thus, in the cleaning position, the deflector is separated from the guide section. This allows cleaning fluid to penetrate the space between the deflector and the guide section, cleaning and / or disinfecting the area.

[0036] Advantageously, the spring can be positioned on the outside of the receiving shaft. This allows the spring to be accessible to the cleaning fluid.

[0037] Preferably, the deflector may have recesses / holes in one side wall. These recesses allow the cleaning fluid to penetrate the interior of the deflector and reach the receiving shaft and / or the spring.

[0038] The task of the present disclosure is further solved by a system consisting of the rod for the spinal implant and the rod bending pliers according to one of the above aspects. Brief description of the characters

[0039] Fig. 1 shows a perspective view of a rod bending pliers according to the present disclosure; Fig. 2 shows an underside of the rod bending pliers according to the present disclosure; Fig. 3 shows a top view of a swivel arm of the bar bending pliers according to the present disclosure; Fig. 4 shows a top view of the rod bending pliers according to the present disclosure; Fig. 5 shows a perspective view of a guide section of the bar bending pliers according to the present disclosure; Fig. 6 shows a side view of a connecting pin of the rod bending pliers according to the present disclosure; Fig. 7 shows a perspective view of a rotary knob of the rod bending pliers according to the present disclosure; Fig. 8 shows a longitudinal section through the rotary knob in Fig. 7 ; Fig. 9 shows a schematic view of a spring of the rod bending pliers according to the present disclosure; and Fig. 10 shows a perspective view of a handle of the rod bending pliers according to the present disclosure. Detailed description of the figures

[0040] Fig. 1Figure 1 shows a rod bending pliers 1. The rod bending pliers 1 have two compressible handles 2 and two swivel arms 4. The handles 2 can be pivoted relative to each other about a first (rotary) joint 6. The swivel arms 4 are each movably connected to the respective handles 2 by a second (rotary) joint 8. Each swivel arm 4 has a bending roller 10. The bending rollers 10 can each be rotated about an axis of rotation that is oriented perpendicular to a longitudinal dimension of the rod bending pliers 1. This allows the bending rollers 10 to roll along a rod (not shown) during movement. In the following, distal is defined as pointing towards the bending rollers 10 and proximal as pointing towards the handles 2.

[0041] Fig. 2Figure 1 shows an underside of the bar bending pliers 1. The first joint 6 has a first joint pin 12, which is mounted in a first joint bore 14 of the respective handle 2. The second joint 8 connects a handle 2 to one of the swivel arms 4 and has a second joint pin 16. The second joint pin 16 is mounted in a second joint bore 18 in the handle 2 and in a proximal joint bore 20 in the swivel arm 4. The two swivel arms 4 cross each other and are pivotally or rotatably connected to each other in a connecting section by a connecting pin 22. The connecting pin 22 is pivotally or rotatably mounted in a central bore 24 in a central section 26 of the swivel arms 4.

[0042] Fig. 3Figure 1 shows a top view of one of the pivot arms 4. Each pivot arm 4 has a proximal end section 28 and a distal end section 30. The proximal joint bore 20, in which the second joint pin 16 of the second joint 8 is mounted, is located in the proximal end section 28. The bending roller 10 is arranged or rotatably mounted in the distal end section 30. The central bore 24 is formed in the central section 26 of the pivot arm 4, which is located between the proximal end section 28 and the distal end section 30.

[0043] Fig. 4Figure 1 shows a top view of the bar bending pliers 1. The bar bending pliers 1 also have a support plate or a cantilever / guide section 34. The cantilever / guide section 34 essentially has a flat, plate-shaped base body 36. A bore 38 is provided on a proximal side of the plate-shaped base body 36, in which the first pivot pin 12 of the first joint 6 is mounted. Thus, the guide section 34 is fixed to the first joint 6. On a distal side of the plate-shaped base body 36, the guide section 34 has an elongated guide groove 40. The connecting pin 22, which movably connects the two pivot arms 4, is axially guided in the guide groove 40. A receiving shaft 42 also projects from the plate-shaped base body 36 of the guide section 34. A deflector / rotary knob 44 is arranged on the receiving shaft 42.The rotary knob 44 is rotatable around the receiving shaft 42 and is mounted to be displaceable in the axial direction of the receiving shaft 42.

[0044] The operation of the bar bending pliers 1 is described below. When a user squeezes the two handles 2 together, the handles 2 pivot about the first joint 6 with the first joint pin 12. This causes the second joints 8 with the second joint pins 16, which are located at the distal end of the handles 2, to move outwards, i.e., away from a symmetry or longitudinal axis of the bar bending pliers 1. The outward movement of the second joints 8 causes a pivoting movement of the pivot arms 4. The proximal end section 28 of the pivot arm 4 pivots outwards with the second joint 8. The connecting pin 22 between the two pivot arms 4 performs a translational movement along the longitudinal extent of the bar bending pliers 1. The distal end section 30, and thus the bending rollers 10, move in a circular path. The rod, which rests against the rotary knob 44 and the two bending rollers 10, can be bent by the circular movement of the bending rollers 10.The bending of the bar depends particularly on the travel distance of the bending rollers 10 on the circular path. The first joint 6 and the second joint 8 provide a transmission between the opening angle / travel distance of the handles 2 and the travel distance of the bending rollers 10.

[0045] Fig. 5Figure 1 shows a perspective view of the guide section 34 with the plate-shaped base body 36. The receiving shaft 42, designed as a cylindrical projection, protrudes from the plate-shaped base body 36. The guide section 34 has the bore 38 in which the first pivot pin 12 is mounted. The receiving shaft 42 is arranged centrally in the longitudinal direction of the base body 36 and thus, like the bore 38, lies on an axis of symmetry of the base body 36. The guide section 34 also has a projecting pin 50. The projecting pin 50 is positioned next to the receiving shaft 42. The receiving shaft 42 has an axial bore 52. A shaft end bolt 46 can be inserted into the bore 52. The shaft end bolt 46 can protrude beyond a diameter of the receiving shaft 42. The guide groove 40 has an elongated recess 48.The guide groove 40 is designed such that a pin head 54 of the connecting pin 22 is axially guided in the guide groove 40. A pin cylinder 56, which protrudes from the pin head 54, has a smaller diameter than the pin head 54. The pin cylinder 56 projects through the elongated recess 48 and is axially guided in it. Thus, the first joint 6 has one translational degree of freedom in the longitudinal direction of the bar bending pliers 1 via the guide groove 40. This translational degree of freedom causes a symmetrical movement of the two pivot arms 4. Fig. 6 shows the connecting pin 22 with the pin head 54, which has a larger diameter than the pin cylinder 56.

[0046] The Figures 7 and 8Figure 44 shows the rotary knob 44. The rotary knob 44 is essentially round and rotatable around the receiving shaft 42. The rotary knob 44 has a contact surface 58 that rests against the guide section 34. The contact surface 58 incorporates (locking) receptacles 60, which are designed or configured to receive the pin 50. When the pin 50 engages in the receptacle 60, the rotatable rotary knob 44 is locked or latched in this position. Depending on the direction of rotation, one side wall of the rotary knob 44 forms different bearing surfaces 62. This means that the rotary knob 44 is not rotationally symmetrical; rather, the contours of the individual bearing surfaces 62 differ. Depending on the position, a different geometry can thus face the bending rollers 10. The bearing surfaces 62 are designed so that the bar (not shown) rests against them and is bent by the combination of the bending rollers 10 and the bearing surface 62.The rotary knob 44 also has a rim that the user can grip. This allows the user to rotate the rotary knob 44 around its axis of rotation and also to move it along the receiving shaft 42. The rotary knob 44 can therefore be lifted off the guide section 34 in the axial direction of the receiving shaft 42. By combining lifting the rotary knob 44 with simultaneous rotation around the receiving shaft 42, the rotary knob 44 can be turned or adjusted to different positions. These different settings of the rotary knob 44 allow the bending behavior or bending radius of the rod to be varied.

[0047] When the rotary knob 44 is lifted and turned such that the pin 50 does not engage in a receptacle 60, but rests on the contact surface 58, the contact surface 58 is spaced apart from the base body 36 of the guide section 34. This position is referred to as the cleaning position. The space between the contact surface 58 and the base body 36 allows cleaning fluid to penetrate between the respective surfaces.

[0048] The rotary knob 44 is pre-tensioned with a spring 64. The spring 64 is in the Fig. 9The spring 64 is shown and is attached to one edge of the rotary knob 44. The other end of the spring 64 is attached to the shaft end bolt 46. The spring 64 runs along an outer surface of the receiving shaft 42. Thus, a spring force from the spring 64 acts towards the receiving shaft 42. When the rotary knob 44 is lifted (by the user) from the guide section 34, the spring 64 is compressed. When the external force on the rotary knob 44 is removed, the spring force pushes the rotary knob back towards the guide section 34. This additionally ensures that the rotary knob 44 engages in the various locking positions. The rotary knob 44 also has recesses / holes 66 in its side wall. This allows cleaning fluid to penetrate particularly well to the receiving shaft 42 and the spring 64. Fig. 10 shows a handle 2 with a first joint bore 14 and a second joint bore 18 for the second joint 8. Reference symbol list

[0049] 1 Bar bending pliers 2 Handle 4 Swivel arm 6 First joint 8 Second joint 10 Bending roller 12 First joint pin 14 First joint bore 16 Second joint pin 18 Second joint bore 20 Proximal joint bore 22 Connecting pin 24 Middle bore 26 Middle section 28 Proximal end section 30 Distal end section 34 Boom / guide section 36 Base body 38 Bore 40 Guide groove 42 Mounting shaft 44 Deflection / rotary knob 46 Shaft end bolt 48 Elongated recess 50 Pin 52 Shaft bore 54 Pin head 56 Pin cylinder 58 Contact surface 60 Mounting 62 Bearing surface 64 Spring 66 Recess

Claims

1. Medical rod bender (1) with compressible handles (2) that are pivotally mounted about a first hinge (6), pivot arms (4), which are movable in opposite directions when the handles (2) are moved, and a deflector (44) with a support surface (62), wherein each pivot arm (4) comprises a bending roller (10) that is movable with the pivot arm (4) and is designed and configured to bend a rod, in particular, a spinal implant, that is inserted into the rod bender (1), wherein the support surface (62) is designed and configured such that the rod rests against the support surface (62) and can be bent against the support surface (62), and wherein the pivot arms (4) each are movably connected to the respective handles (2) via a second hinge (8), characterized in that the pivot arms (4) are movably fastened to one another by a connecting pin (22), which is mounted in a respective bore (24) of the pivot arms (4), and wherein the connecting pin (22) is movably mounted in a guide groove (40) such that the connecting pin (22) has one degree of freedom in the direction of the longitudinal extension of the rod bender (1).

2. Rod-bender (1) according to claim 1, characterized in that the guide groove (40) is formed in a guide section (34) of the rod bender (1).

3. Rod bender (1) according to claim 2, characterized in that the deflector (44) is mounted on a mounting shaft (42) of the guide section (34), in particular in a movable manner.

4. Rod bender (1) according to claim 3, characterized in that the deflector (44) is mounted so as to rotate about the mounting shaft (42).

5. Rod bender (1) according to claim 4, characterized in that the deflector (44) is not rotationally symmetric and, depending on the direction of rotation, forms different support surfaces (62) that preferably define the radius of a rod bend.

6. Rod bender (1) according to any of claims 3 through 5, characterized in that the deflector (44) is mounted so as to be axially movable along the mounting shaft (42).

7. Rod bender (1) according to claim 6, characterized in that a spring (64) is provided between the deflector (44) and the mounting shaft (42), the spring force of which acts in the axial direction of the mounting shaft (42).

8. Rod bender (1) according to claim 7, characterized in that the spring (64) is secured to the mounting shaft (42) at a protrusion, in particular at a protruding shaft end pin (46), of the mounting shaft (42).

9. Rod bender (1) according to any of claims 2 through 8, characterized in that the guide section (34) has a protruding pin (50) which, depending on the orientation of the deflector (44), engages with corresponding receiving portions (60) of the deflector (44) and spaces the deflector (44) apart from the guide section (34) in a cleaning position.

10. Rod bender (1) according to any of claims 1 through 9, characterized in that the bending rollers (10) are each arranged on a distal end section (30) of the pivot arm (4), in particular so as to be rotatable about an axis of rotation.

11. Rod bender (1) according to any of claims 1 through 10, characterized in that the deflector (44) has recesses (66) in a side wall of the deflector (44).

12. A system consisting of a spinal implant rod and a medical rod bender (1) according to any of claims 1 through 11.