Patella Preparation System

Abstract

The present disclosure relates to a patella preparation system (1) comprising a fixation device adapted to fixably hold a patella (2), a guide device (3) coupled to the fixation device so as to be movable relative to the fixation device, preferably by translational and / or tilting movements, and actuation devices (14, 17) for manually moving the guide device (3) relative to the fixation device (9) independently and separately in a translational and tilting manner. Additionally, the present disclosure relates to a method of using the patella preparation system (1) of the present disclosure.

Description

[Technical Field]

[0001] The present disclosure relates to joint arthroplasty, particularly knee arthroplasty and total knee replacement. More particularly, the present disclosure relates to a medical device that allows a surgeon to efficiently and accurately cut / remove the patella in the context of patella resurfacing or patella transplant / replacement. In particular, the present disclosure relates to a patella preparation system / device. Su Regarding. [Background technology]

[0002] The knee joint allows the human leg to flex and articulate during movement. The lower bone (tibia) connects to the upper bone (femur) at the knee. The patella, or kneecap, is the piece of bone that supports the front of the knee joint. Functionally, the patella acts as a shield. The patella is fixed to the quadriceps muscle, which almost completely surrounds the femur, via the quadriceps tendon, and to the tibia via the patellar tendon.

[0003] The knee joint can become nearly or completely nonfunctional due to prolonged overuse, disease, or trauma. In many cases, the best treatment is total replacement (arthroplasty). During total knee replacement, the femoral and tibial surfaces that join at the knee are completely replaced. In many cases, the patella is also at least partially damaged and must be resurfaced or completely replaced. With this background, the patella must be cut or resected, usually along the cross-sectional area of ​​the patella at a specific, predetermined height.

[0004] It is well known that the patella must first be fixed with a patella preparation instrument, which has a guide device / unit that guides a separate cutting / resection instrument. Then, the cutting / resection height, and therefore the height of the guide device / unit relative to the patella, is adjusted by the patella preparation instrument. If the pitch / angle of the instrument relative to the patella is to be changed, the instrument must be released from its fixation relative to the patella and the instrument must be re-fixed to the patella.

[0005] To this end, typical patella preparation instruments / systems are embodied as / have a clamp with at least two clamping portions having multiple prongs configured to clamp onto the patella on its circumferential surface. The cutting height can be adjusted via a height gauge or equivalent adjustment device. As mentioned above, the angle of the cutting device relative to the patella can only be changed by repositioning the entire patella preparation instrument / device on the patella, which is complicated and imprecise. For example, U.S. Pat. No. 5,021,055 A discloses a patella preparation system that includes a fixation device adapted to hold the patella, a guide device coupled to the fixation device so as to be movable relative to the fixation device by translational and tilting movements, and an operating device for manually moving the guide device independently and separately relative to the fixation device in a translational and tilting manner.

[0006] Against this background, The fixation of the patella preparation system on the patella should be improved so that the patella preparation system itself does not inadvertently slip or shift during surgery. Summary of the Invention [Problem to be solved by the invention]

[0007] The above mentioned object is solved by a patella preparation system / instrument according to claim 1 Book Advantageous further developments of the disclosure are the subject matter of the respective dependent claims. [Means for solving the problem]

[0008] In accordance with the principles of the present disclosure, a patella preparation system / instrument includes: a fixation / retention unit / device adapted to (fixatively) retain the patella; a cutting template or guiding unit / device connected to the fixing / holding unit / device so as to be movable relative thereto by (preferably) a translational and / or tilting movement / motion; and a (manual) actuation / operation unit / device / mechanism for manually moving the cutting template or guiding unit / device relative to the fixing / holding unit / device (preferably) independently and separately in a linear and tilting manner, respectively.

[0009] Such a system / device allows, as a first step, the patella to be (separately and independently) held / grasped / clamped by the fixation / holding unit / device, and, as a second step, the cutting template or guiding unit / device can be independently and separately shifted / moved laterally (linearly) and / or tilted relative to the fixation / holding unit / device (and thus relative to the patella) to allow a separate cutting tool being guided by the cutting template or guiding unit / device to achieve the correct cutting position and orientation (angle) relative to the patella.

[0010] More specifically, the patella preparation systems / instruments described herein may be applied to total knee replacement (TKR), a surgical procedure in which flat and / or curved surfaces must be created in or on the bone to allow for proper attachment or implantation of a prosthetic device. In TKR, a series of flat and / or curved surfaces, or "resections," are created to allow for attachment of prosthetic or other devices to the femur, tibia, and / or patella.

[0011] In order to meet the above requirements, a patella preparation system / instrument is proposed according to claim 1. The patella preparation system / instrument is used in the context of patella resurfacing or replacement.

[0012] The patella preparation system / instrument according to the present disclosure comprises, inter alia, a (disc-shaped) cutting template or guide unit / device (hereinafter simply referred to as guide device) that guides the (separate) cutting instrument / tool ​​(not part of the system / instrument), in particular the working end / effector / saw blade of the cutting instrument, used to perform the resection on the patella, and further includes a fixation / retention unit / device (hereinafter simply referred to as fixation device) that fixes the patella preparation system / instrument relative to the patella (or vice versa).

[0013] Advantageously, the patella preparation system / instrument according to the present disclosure allows for adjustment of the angle of a separate cutting tool / instrument relative to the patella without releasing the fixation of the patella via the fixation device. Thus, a surgeon using this patella preparation system / instrument can adjust the position and angle of the cut in two separate steps within the system / instrument itself, without having to remove and reposition the system / instrument relative to the patella to change the cut angle. By adjusting the angle of the patella cut / resection from 0° to ±7°, the patellar inclination angle (the index of medial / lateral inclination of the patellar plane relative to the femur) can be adjusted.

[0014] The cutting tool / instrument may be a surgical saw and the working end of the surgical saw may be a saw blade.

[0015] knees The patella preparation system / instrument includes a (fork-like) clamping device / unit that can be used to facilitate positioning and / or fixation of the guide device / unit relative to the patella. have The clamping device / unit can be transitioned between a clamped position and a released position. In the clamped position, the clamping device encircles the quadriceps and patellar tendons, since the patella is connected to the quadriceps via the quadriceps tendon and to the tibia via the patellar tendon. In the released position, the clamping device is not secured to either the quadriceps or patellar tendons.

[0016] Here, the quadriceps and patellar tendons, which are connected to the patella, are advantageously used to securely fix the patella preparation system / instrument to the patella to prevent it from unintentionally dislodging from the patella. Because the quadriceps and patellar tendons are thick and strong, they can firmly fix the fastening device, and therefore the patella preparation system / instrument, to the patella. Furthermore, using the fastening device to fix the patella preparation system / instrument to the patella allows for good positioning of the patella within the sagittal and flexion planes of the patella. Therefore, by using the fastening device to fix the patella preparation system / instrument to the quadriceps and patellar tendons, the patella preparation system / instrument can be precisely aligned on the patella, regardless of whether the patella is flat, rounded, wavy, or any other shape.

[0017] In a preferred embodiment, the clamping device / unit comprises first and second (arcuate) clamping arms, each having / providing an upper and lower arm element. The upper arm element can be moved relative to the lower arm element, but both elements work together in a clamping manner when the clamping device / unit is in the clamping position. In the clamping position, the first clamping arm element surrounds the quadriceps tendon and the second clamping arm element surrounds the patellar tendon.

[0018] The fastening device / unit configured in this manner is easy to manufacture and handle, and can reliably securely fasten the fastening device / unit.

[0019] Another advantageous embodiment of the patella preparation system / instrument relates to the embodiment of the fastening device / unit (described above), where the fastening device / unit is removably fixed to the patella preparation system / instrument, preferably to the central connecting portion, in particular via a mating system / unit. Even more preferably, the fastening device / unit is automatically / autonomously positioned relative to the fixation device / unit and thus relative to the patella, using at least one spring which may be provided in the central connecting portion of the fixation device.

[0020] Therefore, when there is no need to specifically ensure a secure fixation of the patella preparation system relative to the patella, the clamping device can be easily removed from the patella preparation system. Each patient has an individually configured patella. The spring allows the clamping system to be automatically positioned individually relative to the patient's patella. This allows the surgeon to work quickly and precisely.

[0021] More advantageously, the guide device is adapted to guide a cutting instrument used to perform the patella resection, and the fixation unit / device preferably has an upper fixation portion (upper thrust plate) configured to contact the superior (anterior) surface of the patella and a lower fixation portion (lower thrust plate) configured to contact the inferior (posterior) surface of the patella. The upper and lower fixation portions, which are particularly parallel to each other, are respectively connected to a linking / connecting portion of the patella preparation system / instrument, which is adapted to extend and / or reduce the distance between the upper and lower fixation portions. The guide unit / device is movable in a direction substantially parallel to the length axis of the connecting portion (translational movement) and is tiltable / tiltable relative to the connecting portion, particularly relative to the upper fixation portion. The patella preparation system / instrument further comprises a (manual) actuation / operation unit / device / mechanism (hereinafter simply referred to as the actuation device), which comprises as a first operating unit / part a cutting height adjustment device (first independent and separate operating unit / part) used to position the guide unit / device at a certain height relative to the upper fixation part and thus relative to the patella so that the cutting instrument can perform the patella resection at a preferred cutting height, in particular 1 mm relative to the upper surface of the patella. Furthermore, the (manual) actuation / operation unit / device / mechanism comprises as a second operating unit / part a cutting angle adjustment device (second independent and separate operating unit / part) for adjusting (separately from the height adjustment) the (tilt) angle of the guide device relative to the upper fixation part and thus relative to the patella so that the cutting instrument can perform the patella resection at a preferred angle or preferred slope, in particular a patella cut / resection angle in the range of 0° to ±7° in 1° increments.

[0022] In other words, the patella preparation system / instrument according to the present disclosure includes circumferentially arranged slots. It is good ( Ring-shaped ) The patella preparation system / instrument further comprises a guide disc, the slot being of a height such that at least the working end / effector of the cutting device can be slidably received within the slot to guide the working end relative to the patella. ,SoEach was connected to the central connection part. Preferably has upper and lower fixed portions / arms / thrust plates The patella preparation system / instrument has a fixation unit / device (mechanism), preferably the fixation parts / arms / thrust plates are each connected to the connecting part in a perpendicular manner, and the upper fixation part / arm / thrust plate can be moved relative to the lower fixation part / arm / thrust plate via the slidable two-part structure of the central connecting part, so that the upper and lower fixation parts / arms / thrust plates can surround the patella in a fixed / clamping manner.Furthermore, the patella preparation system / instrument includes an axially guided rotation mechanism with a rotation element (knob) and a cutting height adjustment shaft (U-shaped socket / dome) to which a guide disc is fixedly connected. The device may further include an operating device. The rotating element is rotatable about the length axis of the cutting height adjustment shaft and is therefore connected to the guide disc in a freely rotatable manner (the rotating element is rotatably interconnected with a guide shaft / spindle fixedly connected to the upper fixation part, and the height adjustment shaft is axially supported by the guide shaft / spindle via the rotating element). Thus, when the rotating element is rotated about the cutting height adjustment shaft (socket), the cutting height adjustment shaft (socket) moves upward and / or downward along the non-rotating spindle, adjusting / changing the height of the guide disc relative to the upper fixation part and thus the patella. Furthermore, the patella preparation system / instrument includes a gear wheel mechanism (transmission) comprising at least a gear wheel and a toothed portion configured to mesh with the gear wheel. But it's okay The guide disc is fixed (uniformly connected) to the toothed portion so that it is rotatable / tiltable together with the toothed portion around a tilting axis located within / in the central connecting portion, whereby when the gear wheel is rotated, preferably by means of a separate rotating element (knob), the angle of the guide disc relative to the central connecting portion and therefore relative to the patella can be changed.

[0023] Furthermore, the guide device / unit may be embodied in the form of a disc having a concentrically arranged cylindrical hole whose diameter is at least as large as the maximum diameter of the patella. The disc further comprises a slot extending at least partially / cross-sectionally along the circumference of the disc and extending radially of the disc from its shell surface to its inner cylindrical surface. The slot is at least high enough to accommodate the working end of a cutting instrument. The disc is fixedly, in particular integrally and / or vertically, connected to a guide shaft, in particular a spindle shiftably supported by a cutting height adjustment shaft (U-shaped socket / dome) and threadedly engaged with a rotating element supported by the socket.

[0024] A guiding device / unit configured in this way can easily accommodate and guide the working end of a cutting device, in particular the saw blade of a surgical saw, in the slot of the disc. However, different ways of guiding the cutting device can be envisaged.

[0025] The patella preparation system / instrument is further advantageously embodied with a cutting height adjustment device / unit, which includes a rotating element, particularly a knob, having a first thread, particularly an internal thread, connected to the guide device in a freely rotatable manner. Thus, the rotating element (knob) is rotatable relative to the guide shaft / spindle, but the guide shaft / spindle does not rotate with the rotating element. The spindle has a second thread, particularly an external thread, configured to cooperate with the first thread in such a way that rotation of the rotating element, particularly about the longitudinal axis of the cutting height adjustment shaft, moves the guide shaft / spindle, and thus the disc, along the cutting height adjustment shaft.

[0026] The cutting height adjustment device designed in this way is easy and quick to use, since only the rotating element needs to be rotated. Furthermore, the cutting height adjustment is very precise. Furthermore, since the rotating element is provided separately from the guide shaft, it is possible to prevent the guide device from rotating when the knob is turned.

[0027] Another preferred embodiment of the present disclosure is configured such that the guide shaft includes an internal first guide portion. The cutting height adjustment shaft includes an external second guide portion. The second guide portion of the cutting height adjustment shaft is configured to be complementary to the first guide portion of the guide shaft. Both guide devices may be embodied in a manner that allows them to engage with each other and prevents rotational movement of the guide shaft / spindle relative to the cutting height adjustment shaft (socket), only allowing movement of the guide device and cutting height adjustment device in the length direction of the cutting height adjustment shaft and / or guide shaft.

[0028] The cooperation / engagement of the first and second guide portions effectively prevents the guide device from rotating with the rotating element, and further, the interaction of the first and second guide portions allows for smooth, non-jerky adjustment of the cutting height via rotation of the rotating element.

[0029] The first guide portion may be a female guide device or configured as a groove that may have a flat first sliding surface. The second guide portion may be a male guide device that mates with the first guide portion. Furthermore, the second guide portion may be configured as a rod with a flat second sliding surface that allows the second guide portion to mate with the first guide portion, such that the second sliding surface is in contact with the first sliding surface.

[0030] Additionally, the cutting height adjustment shaft of the cutting height adjustment device may include a scale that indicates to a user of the patella preparation system the height of the disk of the guide device relative to the patella, and therefore the cutting height. The scale may indicate an angle range of 0° to ±7° in 1° increments.

[0031] If the axis is provided with a scale, it is very easy for the user to adjust the preferred cutting height on the patella preparation system.

[0032] Furthermore, in another preferred embodiment of the present disclosure, the cutting angle adjustment device includes a rotating component / element, particularly in the form of a knob, integrally provided with a shaft, configured to be inserted through the central connecting portion, particularly in a direction perpendicular to the longitudinal axis of the central connecting portion. Furthermore, the cutting angle adjustment device includes a gear wheel, particularly a spur gear, fixedly, particularly integrally, connected to the shaft of the rotating component. Furthermore, the cutting angle adjustment device includes a toothed portion configured to mesh with the gear wheel / spur gear, the toothed portion being fixedly connected to the guiding device or the cutting angle adjustment device and tiltably / rotatably supported by the central connecting portion using a rotation / tilt axis. The toothed portion and the guiding device are rotatable relative to each other around the rotation axis. Thus, the guiding device is tiltable relative to the upper fixed portion / portion of the central connecting portion.

[0033] This setting of the cutting angle adjustment device allows for easy adjustment of the angle of the guide device relative to the upper fixation portion and relative to the patella. Rotating the rotating component about the length axis of its shaft also rotates a gear wheel fixed to the rotating component's shaft. This gear wheel meshes with the toothed portion, causing the toothed portion to rotate about the rotation / tilt axis. Because the toothed portion is fixedly connected to the cutting height adjustment shaft, the cutting height adjustment shaft rotates with the toothed portion about the rotation / tilt axis. Because the guide device is movable only in the direction of its length axis relative to the cutting height adjustment shaft, the guide device also rotates with the shaft about the rotation / tilt axis. Thus, the inclination of the guide device relative to the upper fixation portion of the patella preparation system, and therefore relative to the patella, can be changed via the cutting angle adjustment device while the patella preparation system remains fixed to the patella.

[0034] Furthermore, an advantageous embodiment of the present disclosure is one in which the cutting angle adjustment device further includes a locking element, particularly in the form of a knob or bolt, configured to stop any rotation of the rotating component and stop tilting movement of the guide device when the locking element is reversibly brought into contact with the rotating component, e.g., the locking element is pressed down by a user toward the rotating component.

[0035] The locking element can be used to lock a preferred tilt angle of the patella preparation system, particularly the guide device, relative to the patella, thus preventing accidental rotation of the rotation component of the cutting angle adjustment device and therefore unintentional changes to the cutting angle. This locking can be easily reversed once contact between the locking element and the rotation component is released.

[0036] Advantageously, the locking element may have a locking portion in the form of a protruding portion, in particular in the form of a pin, and the shaft of the rotating component may comprise a circumferentially arranged groove configured to receive the locking portion of the locking element when the locking element is in contact with the rotating component.

[0037] This locking mechanism, which includes a locking element and a groove inside the shaft of the rotating element, is easy to achieve and manufacture.

[0038] Additionally, the upper thrust plate may have drill guide elements / portions that can be used to guide a drill relative to the fixation device and thus relative to the patella.

[0039] This setting also allows drilling into the patella to be performed.

[0040] Another preferred embodiment of the present disclosure is one in which the upper fixation portion of the fixation device has at its distal end a receiving portion configured to receive a drill guide element / portion therein.

[0041] This arrangement is a space-saving design, and the receiving part of the fixation device supports the drill guide element, for example against unintentional tilting.

[0042] Furthermore, a patella preparation system according to the present disclosure may be embodied such that the underside of the upper fixation portion, which faces the superior side of the patella, and the upper side of the lower fixation portion, which faces the inferior side of the patella, each have multiple prongs.

[0043] In this way, the fixation device can be easily fixed to the patella.

[0047] Positioning of the system on the patella can be managed by the (clamping) handle or by using the patellar tendons (quadriceps and patellar tendons), which further promotes stability of the system.

[0049] The clamping device may be used to clamp the quadriceps and / or patellar tendons to use them as a reference for cutting, and the clamping device may also be removed from the quadriceps and / or patellar tendons.

[0050] Additionally, the patella preparation system is adapted to position the clamping device against the quadriceps tendon and / or patellar tendon by a spring within a cannon that is part of the connecting portion.

[0051] Once the patella preparation system is placed on (and secured to) the patella, the user adjusts the cutting height using the rotating element of the cutting height adjustment device. can The guide device is then guided on a vertically fixed threaded shaft, on which the rotary element rotates / tap.

[0052] The cutting height is easily visible in front of the instrument via a scale provided on the shaft.

[0053] Once the cutting height is fixed, the user adjusts the cutting slope / angle using the rotating component to lock (unlock) it against the locking element.

[0054] In the cutting angle adjusting device, the gear wheel is inside the fixed part (the upper fixed part and connecting part of the fixing device), and the rotating component is fixed to the gear wheel.

[0055] The toothed part is fixedly connected to the working arm and is located in front of the gear wheel, and is fixed to the fixed part by a rotation axis so that when a user turns the rotating component, the toothed part, and therewith the working arm and cutting height adjustment axis, rotate about the rotation axis.

[0056] Once the user defines the correct angle, the locking element enters the groove in the (shaft of) the rotating component, stopping any rotation.

[0057] As the guiding device is guided by the vertical axis of the fixation part, the guiding device also rotates around the rotation axis. In that way, the user can fix the slope / angle from -7° to +7° in increments of at least 1°.

[0058] The present disclosure will be explained in more detail below based on preferred embodiments using figures, which are schematic in nature and are intended to improve the understanding of the present disclosure, and in which the same elements are referred to by the same reference numerals. [Brief explanation of the drawings]

[0059] [Figure 1] FIG. 1 is a perspective view showing a patella preparation system / instrument according to the present disclosure being secured to the patella. [Figure 2] 13A-13D illustrate a mechanism used to enable the fastening device to be attached to the patella preparation system. [Figure 3] FIG. 10 is a longitudinal cross-sectional view of a patella preparation system with a spring positioned at the connecting portion of the patella preparation system. [Figure 4] FIG. 1 is a side view of a patella preparation system. [Figure 5] FIG. 10 is a perspective cross-sectional view of a cutting height adjustment device of the patella preparation system. [Figure 6] FIG. 1 is a perspective view of the patella preparation system from the user's perspective. [Figure 7] FIG. 10 is a side view showing a patella preparation system, particularly a cutting angle adjustment device, with the toothed portion of the cutting angle adjustment device not angled / tilted. [Figure 8] FIG. 10 is a side view showing a patella preparation system, particularly a cutting angle adjustment device, with the toothed portion of the cutting angle adjustment device being angled / tilted. [Figure 9] FIG. 10 is a cross-sectional side view showing the cutting angle adjustment device in detail. [Figure 10] FIG. 1 is an exploded view showing a patella preparation system according to the present disclosure, particularly showing the major components of the cutting angle adjustment device. DETAILED DESCRIPTION OF THE INVENTION

[0060] In this application, when a first element may be read as being "fixedly connected" to a second element, the phrase "fixedly connected" means that when the first device is moved in any manner, the second device moves with the first device in the same manner.

[0061] FIG. 1 shows a perspective view of a patella preparation system / instrument (PPS) 1 shown in a position to be secured to a patella 2. The patella 2 is in a first position connected to the quadriceps muscle (not shown) via the quadriceps tendon 2a and in a second position diametrically opposed to the first position connected to the tibia (not shown) via the patellar tendon 2b. The PPS 1 includes a guide device / unit 3, preferably in the form of a circular disc or ring 3, having concentrically arranged through-holes 4 providing a circular opening. The disc / ring 3 need not be in the form of a perfect circle, but may be a truncated circle. The disc / ring 3 may also be non-circular, for example, having a rectangular shape. The diameter of the hole 4 is at least as large as the maximum diameter of the patella 2 so that the disc / ring 3 can be positioned around the patella 2 when the PPS 1 is positioned and / or secured to the patella 2.

[0062] The disc / ring 3 includes a slot 5 extending radially and circumferentially around the disc / ring 3. The slot 5 does not have to be disposed around the entire circumference of the disc / ring 3, and may be, for example, two-part. In this case, a first piece 5a of the slot 5 may be disposed so as to extend at least within a region close to a first position where the patella 2 is connected to the quadriceps tendon 2a when the PPS 1 is positioned on the patella 2. Next, a second piece 5b of the slot 5 may be disposed directly opposite the first piece 5a of the slot 5 so as to be disposed in a region close to a second position where the patella 2 is connected to the patellar tendon 2a when the PPS 1 is positioned on the patella 2.

[0063] The slots 5 extend radially of the disc / ring 3 from the shell surface of the disc / ring 3 to its inner cylindrical surface provided by the holes 4. The height of the slots 5 is at least such that the slots 5 can receive the working end of a cutting device 6, such as a saw blade of a surgical saw. The cutting device 6 is provided separately from the PPS 1 and is not part of this disclosure.

[0064] The disc / ring 3 is fixedly, in particular integrally, connected to the socket-like cutting height adjustment shaft 7. In the embodiment of the PPS 1 according to FIG. 1, the disc / ring 3 is connected to the cutting height adjustment shaft 7 in a vertical manner. The cutting height adjustment shaft 7 is configured here as a kind of sleeve or dome, which may have an inclined outer surface and / or may be provided with openings on its outer circumferential surface. In other words, the cutting height adjustment shaft 7 is preferably formed as a U-shaped socket with two parallel, spaced apart legs 7a, 7b interconnected at one end (upper end) by a bar / yoke 7c and connected at the other end (lower end) to the disc / ring 3 in a vertical manner. The connection of the cutting height adjustment shaft 7 to the disc / ring 3 may be reinforced by reinforcing ribs or stiffeners 8. Here, two reinforcing ribs / stiffeners 8 are arranged between the disc 3 and the cutting height adjustment shaft 7.

[0065] Furthermore, the PPS 1 includes a fixation device / unit 9. The fixation device 9 includes an upper fixation part (upper thrust plate arrangement) 10, a lower fixation part (lower thrust plate arrangement) 11 (not shown in FIG. 1 ), and a central connecting part / section 12. The upper fixation part 10 is fixedly, in particular integrally, connected to the central connecting part 12 at an upper connecting part 12a (not shown in FIG. 1 ) of the connecting part 12, preferably by two parallel, spaced-apart connecting arms. The lower fixation part 10 is fixedly, in particular integrally, connected to the central connecting part 12 at a lower connecting part 12b (not shown in FIG. 1 ) of the connecting part 12. The upper connecting part 12a and the lower connecting part 12b are movable relative to each other in a slidable, preferably telescopic, manner along the longitudinal axis of the connecting part 12. In this way, when the PPS 1 is positioned on the patella 2, the upper fixation part 10 can be moved / spaced apart relative to the lower fixation part 11 to fix / clamp the patella 2 therebetween. Here, the upper connection part 12a is configured to be insertable into the lower connection part 12b.

[0066] When the PPS1 is positioned on the patella 2, the upper fixation portion 10 is positioned above the upper surface of the patella 2, and the lower fixation portion 11 is positioned below the lower surface of the patella 2 when the PPS1 is positioned on the patella 2. When the PPS1 is positioned on the patella 2 in a fixed position, the lower surface of the upper fixation portion 10 contacts / fixes the upper surface of the patella 2, and the upper surface of the lower fixation portion 11 contacts / fixes the lower surface of the patella 2.

[0067] 1, the PPS 1 further includes a clamping device 13, which will be described in more detail below. The PPS 1 further includes an operating device having a cutting angle adjustment device 17, which will be described in more detail below, and a cutting height adjustment device 14, which includes a rotating component / element (knob) 15, a spindle 16, and a cutting height adjustment shaft 7, which will be described in more detail below.

[0068] Therefore, the operating device here includes a cutting height adjustment device 14 that separately and independently adjusts the height of the guide device 3 relative to the patella 2, and also includes a cutting angle adjustment device 17 that separately and independently adjusts the inclination / tilt of the guide device 3 relative to the patella 2. Here, the guide device 3 is movable in the linear direction of (the connection part 12 of) the PPS1 by the cutting height adjustment device 14, and is also tiltable / tiltable by the cutting angle adjustment device 17, independently of this, in the up-down direction of (the connection part 12 of) the PPS1, i.e., in the direction between the lower fixation part 11 and the upper fixation part 10.

[0069] The PPS1 further includes a handle 18 shaped like the handle of forceps. The handle 18 has a movable handle arm or branch 18a and a fixed handle arm or branch 18b. The movable handle arm 18a is pivotally connected to the fixed handle arm 18b, which is fixed to the lower connection portion 12b of the connection portion 12. Thus, the movable handle arm 18a, which is pivotally disposed relative to the fixed handle arm 18b, is interconnected with the upper connection portion 12b of the central connection portion 12. Thus, when the handle 18 is manually operated, the upper and lower connection portions 12a, 12b of the central connection portion 12 move relative to each other, moving the upper and lower thrust plates 10, 11 apart and / or closer together.

[0070] Finally, the fixation device includes a manually actuable locking mechanism having a rest lever 19 pivotally supported by the lower connection portion 12b and in locking contact with the upper connection portion 12a in a locked state. Thus, when the rest lever is moved from its locked state to its released state, the fixation device 9 can be moved from a locked position to an open position, in which the lower fixation portion 11 is no longer in contact with the lower surface of the patella 2, via the rest lever 19. In this case, since the upper fixation portion 10 is fixedly connected to the upper connection portion 12a and the lower fixation portion 11 is fixedly connected to the lower connection portion 12b, the upper fixation portion 10 can be moved relative to the lower fixation portion 11 in a translatory manner. Since the upper connection portion 12a is translatably movable relative to the lower connection portion 12b, the upper fixation portion 10 moves together with the upper connection portion 12a relative to the fixed lower fixation portion 11.

[0071] Thus, the upper connecting portion 12a may have a corrugated outer shell surface (bolt) that is complementary to the corrugated inner surface (hole) of the lower connecting portion 12b in the area where the connecting portion 12b receives the upper connecting portion 12a, see FIG. 3 for details.

[0072] FIG. 2 is a perspective view of the clamping device 13 and the upper connecting portion 12a.

[0073] The fastening device 13 may be removably connected to the PPS 1 via the upper connecting portion 12a to simplify positioning of the guide device 3 relative to the fixation device 9 (and thus relative to the patella 2), and therefore the cutting device 6. The fastening device 13 may be transitioned between a fastening position, in which the fastening device 13 surrounds the quadriceps tendons 2a and patellar tendons 2b, and a released position, in which the fastening device 13 is not fixed and is not in contact with the quadriceps tendons 2a and patellar tendons 2b.

[0074] The clamping device 13 is formed in an arcuate shape and here consists of three parts: a first arcuate clamping arm 13a, a second arcuate clamping arm 13b which together with the first clamping arm 13a forms a U-shaped fork, and a connecting or central connecting piece 13c.

[0075] The connecting clamping part 13c is arranged between the first clamping arm 13a and the second clamping arm 13b and connects both arms to each other, for example, each arm 13a, 13b is connected to the connecting part 13c via a plug-like connection.

[0076] Each clamping arm 13a, 13b has an upper arm element 20 and a lower arm element 21 that are movable relative to one another and that act together in a clamping manner when the clamping device is in a clamping position. In the clamping position, the first clamping arm 13a surrounds the quadriceps tendon 2a and the second clamping arm 13b surrounds the patellar tendon 2b. Alternatively, the upper and lower arm elements are fixedly interconnected to one another in the form of a leaf spring.

[0077] The connection clamping portion 13c includes a plug 22, which may be L-shaped. The upper connection portion 12a is at least partially formed as a (hollow) sleeve having a closed / continuous upper surface. A groove 23 is provided inside the sleeve, extending in the longitudinal direction of the sleeve. A clamping portion 24 and a pressing portion 25 are arranged adjacent to each other inside the groove 23. The pressing portion 25 is arranged above the clamping portion 24 (the pressing portion is arranged between the inner upper surface of the upper connection portion 12a and the clamping portion 24). The pressing portion 25 and the clamping portion 24 work together to form a recess (not specifically shown in FIG. 2 ). This recess is sized to accommodate at least the portion of the plug 22 that protrudes from at least the connection clamping portion 13c (the protruding portion). This protruding portion can be interchangeably inserted or snapped into the recess.

[0078] When the protruding portion of the plug 22 is placed inside the recess, the fastening device 13 is attached to the PPS 1. When a user of the PPS 1 wishes to remove the fastening device 13, they can press the pressing portion 25 down onto the fastening portion 24, which enlarges the recess and releases the protruding portion of the fastening device 13. This configuration makes it very easy and quick to attach or detach the fastening device to or from the PPS 1.

[0079] The fastening portion 24 and the pressing portion 25 are disposed in the internal space of the upper connecting portion 12a so as to be slidable in the longitudinal direction of the upper connecting portion 12a.

[0080] FIG. 3 is a longitudinal cross-sectional view of the PPS 1. For ease of understanding, the guide device / disc / ring 3 is not shown in FIG. 3. Here, the clamping device 13 is fixed to the PPS 1. It can be seen that the upper connecting part 12a receives two springs 26, 27 in its internal space (cannon). The first spring 26 is positioned and fixed between the upper end of the upper connecting part 12a and the top of the pressing part 25. The second spring 27 is positioned and fixed between the movable arm 18a and the lower surface of the clamping part 24.

[0081] When movable handle portion 18a is pushed (by a user) towards fixed handle portion 18b, spring 26 is stretched, thus pulling clamping device 13 downward along the length of connecting portion 12 (towards the bottom of connecting portion 12). Thus, the position of clamping device 13 can be easily and automatically changed using springs 26, 27, thereby properly positioning the patella for operation with PPS 1.

[0082] 3, it can be seen that the lower surface of the upper fixation portion (upper thrust plate device) 10 and the upper surface of the lower fixation portion (lower thrust plate device) 11 each include a plurality of prongs that help to fixate the patella 2 between the upper fixation portion 10 and the lower fixation portion 11 when the PPS 1 is fixed to the patella 2.

[0083] 4 is a side view of the entire PPS 1 with the fastening device 13 fixed to the PPS 1. Here, it can be seen that the upper fixation part 12a is provided with a scale indicating the height of the patella in mm. This height scale indicates at what height the PPS 1 is fixed to the patella 2.

[0084] 5 shows a perspective cross-sectional view of the cutting height adjustment device 14 of the PPS 1 connected to the guide shaft 7. As already mentioned above, the cutting height adjustment device 14 comprises a rotating element 15 and a (U-shaped) cutting height adjustment shaft 7. Here, the rotating element 15 is configured as a knob with a disk-shaped upper (manually operable) plate 28, a connecting throat 29, and a disk-shaped lower plate 30. The connecting throat 29 and the lower plate 30 form a flange that is used to connect the rotating element 15 to the interior space of the cutting height adjustment shaft 7 at its upper part. The rotating element 15 is therefore connected to the cutting height adjustment shaft 7 in such a way that it can freely rotate relative to the cutting height adjustment shaft 7 but cannot be shifted axially relative to the cutting height adjustment shaft 7. The cutting height adjustment shaft 7 is therefore provided with a recess that can receive the flange of the rotating element 15.

[0085] The guide shaft 16 is formed partly like a threaded rod or spindle and is provided with a scale on its outer surface that indicates the actual cutting height in mm to the user of the PPS 1. The inner surface of the at least partly hollow cutting height adjustment shaft 7 is provided with a first guide portion 31. This first guide portion 31 is configured to be complementary to a second guide portion 32 that is provided externally on the guide shaft / spindle 16 at the lower portion of the guide shaft 16. Both guide portions are embodied in a manner that prevents rotational movement of the cutting height adjustment shaft 7 relative to the guide shaft 16. The cutting height adjustment shaft 7 is connected / coupled / coupled to the guide shaft 16 (which is fixed vertically) in such a way that the cutting height adjustment shaft 7 can be moved along its longitudinal direction relative to the guide shaft 16.

[0086] Here, the first guide part 31 is configured as a rail on which the flat sliding surface of the first guide part 32 formed in a box-like shape can slide when the rotating element 15 is rotated.

[0087] Furthermore, the rotating element 15 has a concentrically arranged through-hole extending in its longitudinal direction, which is provided with a first screw thread. The guide shaft / spindle 16 has a second screw thread on its outer surface. The first screw thread and the second screw thread are intermeshed with each other.

[0088] Thus, when the rotating element 15 is rotated about the longitudinal axis of the guide shaft / spindle 16, the first thread engages with the second thread, causing the rotating element 15, and with it the cutting height adjustment shaft / socket 7, to move downward or upward along the longitudinal direction of the guide shaft / spindle 16. Because the rotating element 15 is freely rotatable relative to the cutting height adjustment shaft 7, which is slidably connected / coupled to the guide shaft 16, the cutting height adjustment shaft 7 moves upward or downward with the rotating element 15 without rotating. Because the cutting height adjustment shaft 7 is fixedly connected to the disc / ring 3 of the guide device 3, the disc / ring 3 moves with the cutting height adjustment shaft 7. In this way, the height of the disc / guide device 3 of the PPS 1 relative to the patella 2, and therefore the cutting height of the PPS 1, can be adjusted by the cutting height adjustment device 14 configured in this manner.

[0089] 6 shows a perspective view of the PPS 1 from the viewpoint of a user of the PPS 1. The scale on the guide shaft 16 can be seen pointing towards the user.

[0090] Figure 7 shows a side view of some elements of the PPS 1, in particular the section of the PPS that forms the cutting angle adjustment device 17. For ease of understanding, only the upper fixed part 10, the lower fixed part 11, the connecting part 12, the guide shaft 16, and the cutting angle adjustment device 17 are shown in this figure.

[0091] 7 shows the working / lever arms 33, here in a vertical form, fixedly connected (at their intermediate portions) to the guide shaft 16. The working / lever arms 33 are pivotally connected at their respective free (distal) end portions to the upper fixed part 10, the working / lever arms 33 extending between the two parallel, spaced-apart connecting arms of the upper fixed part towards the central connecting portion 12. The working / lever arms 33, and therefore the guide shaft / spindle 16 (fixedly connected to the working / lever arms 33), can therefore pivot upwards and downwards about the connection at their free / distal end portions of the upper fixed part 10.

[0092] The cutting angle adjustment device 17 comprises a rotary element (knob) 34 integral with a rotary shaft 35, which is insertable / insertable into an opening in the upper fixed part 12a of the central connecting part 12, the opening extending transversely through the upper fixed part 12a. The distal / free end of the shaft 35 is fixedly connected to a gear wheel (spur gear) 36. The gear wheel 36 is configured to mesh with a segmented circular toothed section 37, which is preferably fixedly connected to the working / lever arm 33 via a connecting pin 38. As already mentioned above, the working / lever arm 33 is pivotally supported on the upper fixed part 10 by a bearing / pivot shaft 39. In this case, the length axes of the working / lever arm 33 and the upper fixed part 10 are parallel to each other, in particular, are identical.

[0093] In Figure 7, the fingers of the user U are shown. Arrow A indicates the direction in which the user U can turn the rotating component / element 34. Arrow B indicates that the locking element 40 is in the "raised position" in which the locking element 40 is not in contact with the shaft 35 of the rotating component / element 34. Arrow C indicates the direction in which the toothed portion 37 moves when the rotating component / element 34 is rotated in the direction of arrow A. This means that when the rotating element / knob 34 is manually turned / rotated, the working / lever arm 33 pivots about the pivot axis 39, thereby tilting the guide axis / spindle 16 and the cutting height adjustment axis 7 to which the guide disc / ring 3 is fixed.

[0094] FIG. 8 shows the assembly of FIG. 7 when the rotating component / element 34 is rotated in the direction of arrow A in FIG. 7 about the longitudinal axis of the shaft 35 extending from the position shown in FIG. 7. In this case, the gearwheel 36 rotates together with the shaft 35 of the rotating component 34, with the locking element 40 not yet in contact with the shaft 35 (released position). The gearwheel 36 engages with the toothed portion 37, which moves in the direction indicated by arrow C in FIG. 7. The toothed portion 37 is fixedly connected to the working / lever arm 33, so that the working / lever arm 33 rotates together with the toothed portion 37 about the rotation axis 38. The working / lever arm 33 is rotatably supported relative to the upper fixed part 10 by a bearing axis 39. The working / lever arm 33 is vertical and fixedly connected to the guide axis 16. The rotation of the working / lever arm 33 about the rotation axis 38 causes the guide axis / spindle 16 to tilt relative to the upper fixed part 10.

[0095] The cutting height adjustment shaft 7 (shown in FIG. 8 as a diagonal line) is fixedly connected to the guide shaft 16, and the guide device 3 (shown in FIG. 8 as a diagonal line) is fixedly, in particular vertically, connected to the cutting height adjustment shaft 7, so that the guide device 3 is also inclined relative to the upper fixed part 10.

[0096] Therefore, when the rotating component / element 34 is rotated about the length axis of its shaft 35, the length axis D of the working arm 33 is tilted relative to the length axis E of the upper fixation portion 10. As a result, the length axis F of the guide device 3 is also tilted relative to the length axis E of the upper fixation portion 10. As a result, when the rotating component 34 is rotated about the length axis of its shaft 35, the angle of the guide device 3 relative to the upper fixation portion 11 is changed when the PPS 1 is positioned and / or fixed to the patella 2, and therefore the angle of the guide device 3 relative to the patella 2 is changed. The PPS 1 having the cutting angle adjustment device 17 configured in this manner allows for correction of the cutting angle / cutting slope without removing the PPS 1 from the patella 2.

[0097] After the preferred cutting angle has been adjusted using the cutting angle adjustment device 17 (and thus the rotating component 34 has been rotated), the locking element 40 can be brought into contact with the shaft 35 to stop the rotating component 34 from further (unintentional) rotation.

[0098] Figure 9 shows a detailed cross-sectional side view of the cutting angle adjustment device, where it can be seen that the toothed portion 37 is provided with a scale indicating the current cutting angle / gradient / inclination in degrees.

[0099] 10 is an exploded view of the main components of the PPS, in particular the cutting angle adjustment device 17. In this view, the locking element 40 is visible, configured as a pin that is configured to be insertable into a groove 41 in the shaft 35. The groove 41 is arranged circumferentially around the shaft 35. The upper surface of the upper fixed part 12a is provided with a hole that can receive the pin-shaped locking element 40. The hole must be configured so that the locking element 40 can be inserted into the groove 41 in the rotating component 34.

[0100] It can further be seen that the rotation axis 38 is also configured as a pin. The working arm 33 comprises at its distal end a working end 42 which can be used as a guide for a drill (not shown). In this case, the working end 42 comprises a through hole through which the drill can be guided towards the patella 2. To ensure a stable holding of the working end 42, the upper fixation part 10 comprises at its distal end a receiving part 43 which is configured to receive the working end 42.

Claims

1. A patella preparation system, comprising: a fixation device adapted to hold the patella; a guide device for guiding a cutting instrument for performing the patella resection, the cutting instrument not being part of the patella preparation system, the guide device coupled to the fixation device such that the guide device is movable relative to the fixation device by translational and tilting movements; an operating device capable of manually moving the guide device relative to the fixation device in a linear manner and manually moving the guide device relative to the fixation device in a tilting manner independently and separately; a fastening device used to facilitate positioning and / or fixation of the guide device on the patella, which is connected to the quadriceps via the quadriceps tendon and to the tibia via the patellar tendon; Equipped with 10. The patella preparation system of claim 9, wherein the fastening device is configured to be transitioned between a fastening position in which the fastening device encircles the quadriceps tendon and the patellar tendon, respectively, and a released position in which the fastening device is not secured to either the quadriceps tendon or the patellar tendon.

2. 2. The patella preparation system of claim 1, wherein the clamping device includes first and second clamping arms having upper and lower arm elements, respectively, that are movable relative to one another and that act together in a clamping manner when the clamping device is in the clamping position, wherein the first clamping arm encircles the quadriceps tendon and the second clamping arm encircles the patellar tendon.

3. 2. The patella preparation system of claim 1, wherein the fastening device is automatically positioned relative to the fixation device, and thus relative to the patella, via a spring provided in a central connecting portion of the fixation device, the central connecting portion being provided for releasably connecting the fastening device to the fixation device.

4. The patella preparation system of claim 1 , wherein the fixation device is adapted to fixably hold the patella.

5. The patella preparation system of claim 3 , wherein the fastening device is removably attached to the central connecting portion of the fixation device via a clamping or interlocking mechanism.

6. 3. The patella preparation system of claim 2, wherein the fastening device comprises the first fastening arm, the second fastening arm, and a central connecting piece disposed between and connecting the first fastening arm and the second fastening arm to one another.

7. 7. The patella preparation system of claim 6, wherein the central connecting piece is provided with a plug adapted to be inserted or snapped into a recess formed in a portion of the fixation device to attach the fastening device to the fixation device.

8. the recess is formed in a longitudinally extending groove in an upper connection part of the fixation device, the upper connection part being part of a central connection part of the fixation device, the central connecting portion is provided for releasably connecting the clamping device to the fixation device; 8. The patella preparation system of claim 7, wherein the recess is formed between the clamping portion and the pressing portion such that the plug of the central connecting piece is retained in the recess between the clamping portion and the pressing portion disposed in the groove.

9. 9. The patella preparation system of claim 8, wherein the pressing portion is movable relative to the clamping portion to transition between an insertion position in which the clamping portion and the pressing portion form the recess to securely hold the plug of the clamping device, and a release position in which the clamping portion and the pressing portion form the recess in which the plug of the clamping device is released.

10. The patella preparation system of claim 1 , wherein the fastening device is arcuately formed.

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