Device for aligning a tibial cutting block, method for setting up the device

Abstract

Device (100) for the kinematic alignment of a tibial cutting block, wherein the device (100) comprises a first correction device (106, 108, 111) and a second correction device (104, 108, 114), wherein the first correction device (106, 108, 111) is designed to correct a flexion angle, wherein the second correction device (104, 108, 114) is designed to correct a tibial cutting height, wherein the first correction device and the second correction device comprise a guide (108) for a rod (104) for aligning the tibial cutting block, wherein the guide (108) is rotatable for correcting the flexion angle, and wherein the rod (104) is linearly movable with respect to the guide (108) for correcting the tibial cutting height. The device comprises an instrument set and a method for setting up the device.

Description

[0001] The invention relates to a device for the kinematic alignment of a tibial cutting block and a method for setting up the device.

[0002] US 10 709 458 B1 discloses a surgical tool and a method for kinematic alignment in a total knee replacement, which enables kinematic alignment by adjusting a tibial slope, wherein a tibial cutting height changes with the adjusted tibial slope.

[0003] The device and method for kinematic alignment of the tibial cutting block offer an easy-to-use way to transfer the tibial cutting height when transferring a cut from the femur to the tibia, to compensate for a changed tibial cutting height resulting from forced flexion of the knee, and to adjust a native tibial slope according to preoperative planning.

[0004] The device comprises a first correction device and a second correction device, wherein the first correction device is designed to correct a flexion angle, wherein the second correction device is designed to correct a tibial cutting height, wherein the first correction device and the second correction device comprise a guide for a rod for aligning the tibial cutting block, wherein the guide is rotatable for correcting the flexion angle, and wherein the rod for correcting the tibial cutting height is linearly movable with respect to the guide.

[0005] For example, the first correction device and the second correction device have means for setting a correction of the tibial cutting height adapted to the correction of the flexion angle.

[0006] The means for setting the correction of the tibial cutting height adapted to the correction of the flexion angle comprise, for example, a first scale and a second scale, wherein the correction of the flexion angle can be adjusted on the first scale, wherein the correction of the tibial cutting height can be adjusted on the second scale, and wherein the first scale and the second scale clearly identify mutually adapted corrections of the flexion angle and the tibial cutting height, in particular with the same scale value, preferably the same angle indication.

[0007] The device comprises, for example, an alignment rod for alignment on a tibial anterior edge and at least one receptacle for the alignment rod, wherein the alignment rod and the receptacle comprise means for adjusting an angle at which the alignment rod extends from the receptacle.

[0008] The device comprises, for example, two receptacles arranged at different distances from a posterior side of the second fastening part.

[0009] The means for adjusting the angle comprise, for example, an angle at which the receptacle extends with respect to a mechanical axis and at least one angle in the alignment rod.

[0010] The first correction device comprises, for example, a fastening part for fastening the device to the femur or a femoral trial implant, wherein the guide is rotatable with respect to the fastening part for adjusting the correction of the flexion angle.

[0011] The rod has, in particular on its posterior side, a rack extending between a proximal and a distal end of the rod, wherein the guide has a gear, and wherein the gear and the rod are arranged in the guide such that the gear engages the rack.

[0012] An instrument set comprises the device, wherein the device comprises at least one receptacle for an alignment rod and the instrument set comprises alignment rods each with a different angle or an alignment rod with different angle adjustment options.

[0013] The method for setting up the device provides that alignment rods each having a different angle, or an alignment rod with different angle adjustment options is provided, wherein an alignment rod is arranged such that the alignment rod extends from the recess at a selected angle.

[0014] Further advantageous embodiments can be found in the following description and the drawing. The drawing shows: Fig. 1 a schematic representation of a side view of a device for the kinematic alignment of a tibial cutting block, Fig. 2 a schematic representation of a side view of a first part of the device, Fig. 3 is a schematic representation of a side view of a second part of the device, Fig. 4 a schematic representation of a side view of a third part of the device, Fig. 5 is a schematic side view of a fourth part of the device, Fig. 6 a schematic representation of a fifth part of the device, Fig. 7 a schematic representation of a section through a part of the device.

[0015] In Fig. 1 is a schematic representation of a side view of a device 100 for the kinematic alignment of a tibial cutting block.

[0016] The tibial cutting block is in Fig. 1 not shown.

[0017] The device 100 comprises a first fastening part 101. In the example, the first fastening part 101 comprises a coupling device 103 for fastening the tibial cutting block to the first fastening part 101.

[0018] The device 100 comprises a second fastening part 102.

[0019] The first fastening part 101 is designed to fasten the first fastening part 101 to the second fastening part 102.

[0020] The second fastening part 102 is designed to fasten the second fastening part 102 to the first fastening part 101.

[0021] In the example, the first fastening part 101 and the second fastening part 102 are adjustable anteriorly and posteriorly attached to each other.

[0022] It can be provided that the first fastening part 101 is fixed to each other anteriorly and posteriorly with respect to the second fastening part 102 in an immovable manner.

[0023] The second fastening part 102 has a rod 104 for correcting the tibial cutting height. The rod 105 is arranged on the proximal side of the second fastening part 102. The rod 104 extends proximally from the second fastening part 102 to a proximal end of the device 100. The rod 104 and the second fastening part 102 are integral in the example.

[0024] The second fastening part 102 is designed to fasten an alignment rod 105 to the second fastening part 102.

[0025] In the example, the device 100 comprises the alignment rod 105. The alignment rod 105 is designed to align the device 100 with a tibial anterior edge.

[0026] The alignment rod 105 is disposed on the distal side of the second attachment portion 102 at the distal end of the device 100. The alignment rod 105 extends distally from the second attachment portion 102 at the distal end of the device 100.

[0027] The device 100 has a third fastening part 106.

[0028] The second fastening part 102 is designed to fasten the second fastening part 102 to the third fastening part 106.

[0029] The third fastening part 106 is designed to fasten the third fastening part 106 to the second fastening part 102.

[0030] In the example, the second fastening part 102 and the third fastening part 106 are fastened to each other in a proximally and distally adjustable manner.

[0031] The third fastening part 106 has a posterior end 107 at which the device 100 can be arranged on the femur or on a femoral trial implant.

[0032] For example, the end 107 is configured to arrange the device 100 at two posterior-distally extending bores in the femur. For example, the end 107 comprises a posteriorly extending alignment pin for each bore, which is configured to be inserted into the respective bore.

[0033] For example, a locking mechanism is provided at the end 107, which is designed to arrange the end 107 on the dowel pins. The dowel pins, the borehole and the locking mechanism are in Fig. 1 not shown.

[0034] The locking mechanism includes, for example, a wing screw for each dowel pin, with which the respective dowel pin can be fixed in the respective drill hole.

[0035] The device 100 has a guide 108. The rod 104 is linearly movable relative to the guide 108. The guide 108 is configured to guide the rod 104 laterally, medially, anteriorly, and posteriorly relative to the third attachment part 106 in a proximal or distal movement of the rod 104 for correcting the tibial incision height.

[0036] The guide 108 is rotatably mounted on the third attachment part 106 about a rotation axis 109 to correct the flexion angle. The rotation axis 109 extends from a lateral side of the third attachment part 106 to a medial side of the third attachment part 106.

[0037] The third fastening part 106 has a bracket 110 at its front. The bracket 110 has a first scale 111 for correcting the flexion angle. In the example, the first scale 111 is an angle scale. The first scale 111 indicates the correction of the flexion angle between -10° and +20° in one-degree increments around a zero position of the first scale 111 marked 0°. In the example, the zero position of the first scale 111 corresponds to a correction of the flexion angle by 0°, i.e., no correction of the flexion angle.

[0038] In the example, device 100 is configured to compensate for an extension deficit of up to 20°. Other angle ranges are also possible. For example, up to an extension deficit between 10° and 15°, in particular 10° or 15°. This eliminates the need to loosen the ligaments in the knee to allow the leg to extend further.

[0039] In the example, the guide 108 has a device 112.

[0040] In the example, the device 112 is designed to display the correction of the flexion angle on the bracket 110.

[0041] In the example, the device 112 is configured to fix the bracket 110 to establish a set correction of the flexion angle. For example, the device 112 is configured to clamp the bracket 110. In the example, the device 112 is configured to release the bracket 110 to set a correction of the flexion angle for a rotation of the guide 108 relative to the third fastening part 106. For example, the device 112 comprises a screw clamp configured to clamp or release the bracket 110.

[0042] As a result, the guide 108 is fixed with respect to the third fastening part 106 at a set angle of rotation, ie the desired correction of the flexion angle.

[0043] The device 100 has a profile 113 with a second scale 114. In the example, the second scale 114 is a template scale for adjusting the tibial cutting height.

[0044] The profile 113 is arranged on the guide 108. In the example, the profile 113 is arranged on a proximal side of the guide 108. In the example, the profile 113 extends proximally from the third fastening part 106.

[0045] In the example, the rod 104 is arranged to be movable in the proximal and distal directions relative to the profile 113. In the example, the profile 113 is designed to guide the rod 104 in a movement of the rod in the proximal and distal directions, in the medial and lateral directions.

[0046] In the example, the profile 113 is arranged at the proximal end of the device 100. In the example, the profile 113 is arranged at the proximal end of the rod 104. The second scale 114 is configured to indicate the correction of the tibial cutting height. The second scale 114 extends from a proximal side of the profile 113 to a distal side of the profile 113.

[0047] The first scale 111 and the second scale 114 are coordinated. In the example, a correlation between the first scale 111 and the second scale 114 is provided.

[0048] In the example, the first scale 111 indicates the correction of the flexion angle between -10° and +20° in one-degree increments around a zero position of the first scale 111 marked 0°. The zero position of the second scale 114 corresponds to the correction of the tibial cutting height, which is provided in the zero position of the first scale 111 for a correction of the flexion angle by 0°, i.e., no correction of the flexion angle. In the example, the tibial cutting height in the zero position of the second scale 114 is provided to be a predetermined height, e.g., 10 mm. The tibial cutting height assigned to the zero position can be more or less than 10 mm.

[0049] The first scale 111 and the second scale 114 are coordinated in such a way that the tibial cutting height is the specified height, e.g. 10 mm, when the same angle is set on the first scale 111 and the second scale 114.

[0050] In the example, the rod 104 is movable relative to the second scale 114. In the example, the rod 104 has a toothed rail 115. In the example, the guide 108 has a gear 116. The toothed rail 115 and the gear 116 mesh with one another in the example. The gear 116 and the toothed rail 115 are designed to enable the distal and proximal movement of the rod 104 in the guide 108 in the region of the second scale 114. This means that the rod 104 can be extended or retracted to match the set correction of the flexion angle, so that the tibial incision height is the specified height, e.g., 10 mm, when the rod 104 is suitably adjusted.

[0051] When using the device 100, it is provided that the device 100 is arranged such that the alignment rod 105 extends parallel or substantially parallel to the anterior tibial edge.

[0052] The first fastening part 101, the second fastening part 102, the end 107, the rod 104 and the alignment rod 105 are arranged at angles to each other with which the assigned height is achieved as the tibial cutting height.

[0053] In the example, it is provided that the rod 104 extends parallel or substantially parallel to the mechanical axis 117 when the device 100 is used.

[0054] The guide 108, which is rotatable with respect to the third fastening part 106, and the first scale 111 represent parts of a first correction device which is designed to correct the flexion angle.

[0055] The rod 104 movable in the guide 108 and the second scale 114 represent parts of a second correction device which is designed to correct the tibial cutting height.

[0056] The first scale 111 and the second scale 114 represent means for setting a correction of the tibial cutting height adapted to the correction of the flexion angle.

[0057] In Fig. 2 shows a side view of the third fastening part 106 and the guide 108.

[0058] In the example, the bracket 110 is connected to a body 202 of the fastening part 106 by two webs 201. In the example, the device 112 has a pointer 203 designed to indicate the correction of the flexion angle on the first scale 111. In the example, the pointer 203 is arranged in a recess 204 in the third fastening part 106. In the example, the recess 204 is enclosed by the body 202, the webs 201, and the bracket 110.

[0059] In the example, the rotation axis 109 is arranged between the recess 204 and the end 107 in the body 202.

[0060] The guide 108 includes a channel 205 configured to receive the rod 104. In the example, the gear 116 is arranged in the guide 108 for rotation about an axis 206 extending from the lateral to the medial side of the guide 108. In the example, the axis 206 is arranged on the proximal posterior side of the guide 108 adjacent to the channel 205. The gear 116 is configured to engage the teeth of the rack 115 when the rack 115 is arranged in the channel 205.

[0061] The guide 108 has a groove 207 on its proximal side for fastening the profile 113 to the guide 108.

[0062] In Fig. Figure 3 schematically shows a side view of the second fastening part 102. In the example, the rod 104 is arranged at a particularly right angle 303 with respect to a proximal edge 301 of a body 302 of the second fastening part 102.

[0063] In the example, the second fastening part 102 has two receptacles 304 for the alignment rod 105, which are arranged at a distance from one another on the distal side of the body 302. In the example, one of the receptacles 304 is arranged on the posterior side of the body 302, with the other receptacle 304 being arranged further away from the posterior side of the body 302. This allows different distances of the alignment rod 105 to the anterior edge of the tibia to be set.

[0064] The second fastening part 102 has a receptacle 306 in the body 302, which extends from the anterior to the posterior side of the body 302. The receptacle 306 is designed to receive a rod arranged on the first fastening part 101.

[0065] In Fig. Figure 4 schematically shows a side view of the first fastening part 101 with the coupling device 103 for attaching the tibial cutting block to the first fastening part 101. The first fastening part 101 comprises a body 401 that includes the coupling device 103. The body 401 has the rod 402 for connecting the first fastening part 101 to the second fastening part 102. In the example, the rod 402 extends anteriorly from the body 401 on an anterior side of the body 401.

[0066] In Fig. 5 shows a side view of the profile 113 with the second scale 114.

[0067] The profile 113 has a fastening element 501 on its distal side for fastening the profile 113 to the guide 108. The fastening element 501 comprises, for example, a spring that can be inserted into the groove 207 in the guide 108.

[0068] In Fig. 6 schematically shows a side view of the alignment rod 105. The alignment rod 105 has two end faces 601, which are designed to be received by the respective receptacle 304 in the second fastening part 102.

[0069] The alignment rod 105 has at least one angle 602 on at least one of its end faces 601. The respective angle 602 changes the direction in which the alignment rod 105 extends from the receptacle 304.

[0070] The alignment rod 105 can be arranged such that the alignment rod 105 extends to the second fastening part 102 at an angle selectable from the angles provided on the alignment rod 105.

[0071] In Fig. 7 is a schematic cross-section through the second fastening part 102, the receptacle 306 for the rod 402 and the receptacles 304 for the alignment rod 105.

[0072] With an alignment rod 105, for example, four angles 0°, 1°, 2°, 3°, 4° can be set.

[0073] The holder for the alignment rod 105 is arranged, for example, at an angle 701, e.g., of 5°, to the mechanical axis. A parallel 117' to the mechanical axis is Fig. 7 shown.

[0074] In the example, the device 100 is designed for a typical angle of 3° between the mechanical axis and the anterior edge of the tibia.

[0075] The 5° angle includes an offset of -2° to the 3° angle, which represents the typical angle between the mechanical axis and the anterior tibial edge. The offset of -2° is intended to ensure that the entire correction can be performed with just one alignment rod 105. The offset of -2° is compensated for by the angle designated by the first value 2 in the following table. The second value in the table indicates a designation on the alignment rod 105 that specifies the magnitude and sign of a correction to the typical angle (3°) between the mechanical axis and the anterior tibial edge. The result in the table represents the total correction of the typical angle (3°) by the alignment rod 105. In the example, the second value 0 cancels out the correction of the offset of -2°: 2−2=0 2−1=1 2+0=2 2+1=3 2+2=4

[0076] For example, different alignment rods 105, each with a different angle, or one alignment rod 105 with different angle adjustment options are provided.

[0077] To set up the device 100, the device 100 is assembled. The alignment rod 105 is positioned so that the alignment rod 105 extends from the recess 304 at a selected angle.

[0078] In the example, the correction of the flexion angle and the correction of the tibial cutting height are carried out after the device 100 is arranged on the femur or on the femoral trial implant. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 10 709 458 B1

[0002]

Claims

[1] Device (100) for the kinematic alignment of a tibial cutting block, characterized by that the device (100) comprises a first correction device (106, 108, 111) and a second correction device (104, 108, 114), wherein the first correction device (106, 108, 111) is designed to correct a flexion angle, wherein the second correction device (104, 108, 114) is designed to correct a tibial cutting height, wherein the first correction device and the second correction device comprise a guide (108) for a rod (104) for aligning the tibial cutting block, wherein the guide (108) is rotatable for correcting the flexion angle, and wherein the rod (104) is linearly movable with respect to the guide (108) for correcting the tibial cutting height. [2] Device (100) according to claim 1, characterized bythat the first correction device (106, 108, 111) and the second correction device (104, 108, 114) have means (111, 114) for setting a correction of the tibial cutting height adapted to the correction of the flexion angle. [3] Device (100) according to claim 2, characterized by that the means (111, 114) for setting the correction of the tibial cutting height adapted to the correction of the flexion angle comprise a first scale (111) and a second scale (114), wherein the correction of the flexion angle can be adjusted on the first scale (111), wherein the correction of the tibial cutting height can be adjusted on the second scale (114), and wherein the first scale (111) and the second scale (114) clearly identify mutually adapted corrections of the flexion angle and the tibial cutting height, in particular with the same scale value, preferably the same angle indication. [4] Device (100) according to one of the preceding claims, characterized bythat the device (100) comprises an alignment rod (105) for alignment with a tibial anterior edge and at least one receptacle (304) for the alignment rod (105), wherein the alignment rod (105) and the receptacle (304) comprise means (602, 701) for adjusting an angle at which the alignment rod (105) extends from the receptacle (304). [5] Device according to claim 4, characterized by that the device comprises two receptacles (304) which are arranged at different distances from a posterior side of the second fastening part (102). [6] Device according to claim 4 or 5, characterized by that the means for adjusting the angle comprise an angle (602) at which the receptacle (304) extends with respect to a mechanical axis (107) and at least one angle (701) in the alignment rod (105). [7] Device (100) according to one of the preceding claims, characterized bythat the first correction device (106, 108, 111) comprises a fastening part (106) for fastening the device (100) to the femur or a femoral trial implant, wherein the guide (108) is rotatable with respect to the fastening part (106) for adjusting the correction of the flexion angle. [8] Device (100) according to one of the preceding claims, characterized by that the rod (104), in particular on its posterior side, has a rack (115) which extends between a proximal and a distal end of the rod (104), wherein the guide (108) has a gear (116), and wherein the gear (116) and the rod (104) are arranged in the guide (108) such that the gear (116) engages in the rack (115). [9] Instrument set, characterized bythat the instrument set comprises the device (100) according to one of claims 1 to 8, wherein the device (100) has at least one receptacle for an alignment rod, wherein the instrument set comprises alignment rods (105) each with a different angle or an alignment rod (105) with different angle adjustment options. [10] Method for setting up the device (100) according to one of the preceding claims, characterized by that alignment rods (105) each having a different angle, or an alignment rod (105) with different angle adjustment options is provided, wherein an alignment rod (105) is arranged such that the alignment rod (105) extends from the recess (304) at a selected angle.

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