Adjusting tool for support device and such support device

Abstract

The adjustment tool of the invention is intended for a support device. The adjusting tool comprises a first adjusting shaft (34), a second adjusting shaft (35) and a third adjusting shaft (41), and a cross beam (33) which can be adjusted by at least one of the adjusting shafts (34, 35 and / or 41) to rotate in at least one direction. A first adjustment shaft (34) is attached to the cross beam (33), a second adjustment shaft (35) is attached to the first adjustment shaft (34), and a third adjustment shaft (41) is attached to the second adjustment shaft (35). Furthermore, the adjustment means comprise a pair of attachment arms (36), one of which is laterally movable along the beam on one side of the first adjustment axis and the other laterally movable on the other side of the same adjustment axis. The support device according to the invention has a component to be positioned and supported, which is connected to the adjustment tool, which is coupled on the one hand to the transverse support arm of the support device and on the other hand to the component to be supported. The support device is, for example, a support device for surgical patient positioning, such as for corrective bone dislocation or tibia intramedullary nail fixation.

Description

Technical Field

[0001] The present invention relates to an adjusting tool for the mutual positioning of components of a mechanical device, in particular a support device, and its use. The present invention also relates to such support devices. Background Art

[0002] Workpiece fixing, positioning and support devices are used to create a secure fulcrum for a workpiece or an operation that needs to be supported during the operation, in order to improve precision and accuracy. The components in such devices should be firmly positioned at specific positions, locations and / or orientations so that the device can support the operation. Such support devices are suitable for a variety of different types of operations and are accordingly designed to have a position positioning, location positioning and support function, or only one of these functions. The positioning components can, for example, ensure the geometric stability of the support device and keep it in the correct position and orientation suitable for the operation.

[0003] The positioning components of a support or positioning device can include movable and / or rotatable arms and shafts fixed together by screws or pins, and sometimes also include clamps and surfaces. These components ensure the correct positioning of the components and keep their positions unchanged throughout the operation. The surfaces, arms and shafts provide support, and the pins and screws achieve precise positioning. For example, the clamp allows the support device or its components to be disassembled or their positions to be adjusted.

[0004] Surgical positioning refers to the operation of placing a patient in a specific position during a surgical procedure. The purpose of selecting and adjusting a specific surgical position is to allow access to the surgical site while ensuring the safety of the patient. Usually, the patient must be in an unnatural position to access the surgical site.

[0005] For example, the lithotomy position is a commonly used position for surgical procedures and medical examinations involving the pelvis and lower abdomen, and is also a commonly used position for childbirth in Western countries. In the Trendelenburg position, the patient lies supine or flat on an inclined plane at an angle of 15 to 30 degrees, with the feet higher than the head. Similarly, in the reverse Trendelenburg position, the patient lies supine on an inclined plane, but the head is elevated. In particular, intramedullary nailing of the tibia can be performed when the patient is lying supine on a radiolucent operating table or fracture table.

[0006] Different positioning and support devices are used to position surgical patients. Since patients have different body shapes, these devices need to be adjusted individually for each patient. Therefore, there are some components in the support device that need to be adjusted in terms of their height and position, the distance and position between each other, and these components can extend or shorten in different directions (such as vertical, horizontal or inclined directions), and at the same time, the required adjustments need to be made according to, for example, the height and body shape ratio of the patient to be fixed in the surgical position.

[0007] In addition, the adjustable components of the device for surgical positioning include arms, shafts, screws, pins, etc. Unique positioning attachments and the entire such device must be designed to achieve a specific position and ensure patient safety and support. Each such device is equipped with a variety of accessories and attachments, such as components for lifting the legs off the operating table surface during gynecological, urological, and orthopedic surgeries.

[0008] Intramedullary nailing is an orthopedic surgery used to treat tibial fractures, which refers to inserting a metal nail into the medullary cavity of the tibia. Tibial fractures are a common injury, especially among young and middle-aged adults. Fractures can be caused by falls, accidents, or strong impacts to the leg. The treatment of tibial fractures usually includes reduction, that is, positioning the bone ends at the fracture site to the appropriate position.

[0009] Intramedullary nailing is the most commonly used method for treating tibial fractures. The nail is inserted into the medullary cavity through the tendon below the patella. Once the nail is in place, screws are inserted through its two ends to fix the bone in the desired position.

[0010] The role of intramedullary nailing of the tibia is to keep the fractured bone segments aligned, so that the bone ends at the tibial fracture site are in a straight line, and then enable the tibia to ossify to the correct position.

[0011] Traditionally, the intramedullary nail is thus inserted into the bone from the top of the tibia, and studies have shown that this causes knee anterior pain in a considerable number of patients, namely the so-called anterior knee pain symptoms.

[0012] In addition, in a still commonly used surgical method, the leg to be operated on is placed at an angle of more than 90 degrees to a circular support. In addition, forward and downward traction is applied obliquely to the leg to align the end of the damaged tibia. This operation may cause the nerves at the back of the knee joint to be squeezed, increasing the risk of nerve injury. When using a wedge pillow, an assistant (i.e., another surgeon) is required to hold the position of the leg. The task of the assistant during the operation is to maintain the required traction on the leg so that the bone ends are aligned and the leg does not move during drilling the intramedullary nail.

[0013] There are two known intramedullary nailing techniques for the tibia. In the first method, a traction table designed for this surgery is used, but there are many problems. For example, the surgical preparation is time-consuming and imaging is difficult. If the patient is not positioned correctly, nerve injury may occur, and in this method, the surgeon must operate in an ergonomic working position. In the second method, intramedullary nailing is performed on a standard operating table using a wedge pillow designed specifically for tibial intramedullary nailing. The problem with this operation is that the leg keeps moving, so another orthopedic surgeon or trauma surgeon is required to support the leg during the operation. In addition, in this wedge pillow operation where the leg can move a lot, it is easy to cause tissue damage and vascular damage to the calf muscles.

[0014] In common surgical methods, it is also necessary to drill through the calcaneus with a needle and attach it to a traction device. There are important nerve structures and soft tissues in the calcaneus area, which are more vulnerable to injury.

[0015] The patent publication document CN110537964A is cited as the prior art, which discloses a device for tibial intramedullary nail fixation, in which the length of the bone can be adjusted by a needle passing through the bone.

[0016] The object of the present invention is to provide an auxiliary element, which is usually used as an adjustment element in a support device to facilitate the adjustment of components in the support device that need to be adjusted in terms of their height and position, distance and position from each other.

[0017] A specific object of the present invention is to provide a device that can achieve a safer and more patient - suitable tibial intramedullary nail surgery. Summary of the Invention

[0018] The adjustment tool of the present invention is intended for use in a support device. The adjustment tool includes a first adjustment shaft, a second adjustment shaft, and a third adjustment shaft, and a beam that can be adjusted for rotational movement in at least one direction by at least one of the adjustment shafts. The first adjustment shaft is attached to the beam, the second adjustment shaft is attached to the first adjustment shaft, and the third adjustment shaft is attached to the second adjustment shaft. In addition, the adjustment tool includes a pair of attachment arms, one of which moves laterally along the beam on one side of the first adjustment shaft, and the other moves laterally along the beam on the other side of the first adjustment shaft.

[0019] The support device of the present invention has components to be positioned and supported. The support device has an adjustment tool that is connected on the one hand to its lateral support arm and on the other hand to the component to be supported. The adjustment tool includes a first adjustment shaft, a second adjustment shaft, and a third adjustment shaft, and a beam that can be adjusted for rotational movement in at least one direction by at least one of the adjustment shafts. The first adjustment shaft is attached to the beam, the second adjustment shaft is attached to the first adjustment shaft, and the third adjustment shaft is attached to the second adjustment shaft. In addition, the adjustment tool includes a pair of attachment arms, one of which moves laterally along the beam on one side of the first adjustment shaft, and the other moves laterally along the beam on the other side of the first adjustment shaft.

[0020] In particular, the support device is a support device for positioning a surgical patient, such as for bone dislocation correction or tibial intramedullary nail fixation.

[0021] The support device for bone dislocation correction or tibial intramedullary nailing of the present invention includes a frame, which is composed of vertical supports and longitudinal and transverse horizontal supports. The support device further includes a traction pin to be passed through the tibia, and a guide that is slidably coupled to the longitudinal horizontal support of the support device. The guide includes a first detector for adjusting the position of the traction pin in the transverse direction relative to the upper joint surface of the tibia, and a second detector for adjusting the position of the traction pin in the vertical direction and passing the traction pin through the tibia in the transverse direction of the tibia. The first attachment arm is configured to be attached to one end of the frame and is attached to the end of the traction pin that has passed through the tibia in the transverse direction through the guide. The support device further includes an adjustment tool that is coupled to a horizontal support slidably attached between a portion of the longitudinal supports at the other end of the first attachment arm in the frame. The adjustment tool includes a first adjustment shaft, a second adjustment shaft, and a third adjustment shaft, and a beam that can be adjusted for rotational movement in at least one direction through at least one of the adjustment shafts. The first adjustment shaft is attached to the beam, the second adjustment shaft is attached to the first adjustment shaft, and the third adjustment shaft is attached to the second adjustment shaft. In addition, the adjustment tool includes a pair of attachment arms, one of which moves transversely along the beam on one side of the first adjustment shaft, and the other of which moves transversely along the beam on the other side of the first adjustment shaft.

[0022] Preferred embodiments of the present invention have the following features, which are disclosed in the dependent claims.

[0023] The terms "positioning" and "position" used in the context of the present invention include all types of displacements, such as axial displacement, circumferential displacement, rotational movement, and linear movement, to bring a component to a desired position.

[0024] In a preferred embodiment, the first adjustment shaft, the second adjustment shaft, and the third adjustment shaft are perpendicular to each other.

[0025] The rotational movement includes a first rotation of the beam about its midpoint in the horizontal plane. In other words, this is a rotation of the beam about a vertical axis in the horizontal plane. The rotational movement may further include a second rotation of the beam about its midpoint in the vertical plane, that is, a rotation of the beam about a vertical axis in the vertical plane. In addition, the rotational movement may include a third rotation of the beam, which is an angular rotation along an arc defined by the distance (radius of curvature) between the third adjustment shaft and the beam. In other words, when the third adjustment shaft is turned back and forth, the beam moves back and forth along a circular path in a circular motion.

[0026] The first adjustment shaft, the second adjustment shaft, and the third adjustment shaft can be rotated relative to each other simultaneously or separately by locking screws in their respective adjustment shafts.

[0027] There are a first locking screw for the first rotation and a second locking screw for the second rotation. The first locking screw itself holds the first adjustment shaft in place, but for further security, a positioning screw fixed to the second adjustment shaft can be provided to further ensure that the first adjustment shaft remains in place. There is a third locking screw for adjusting angular rotation. A fourth locking screw extends perpendicular to the first adjustment shaft to fix it to the beam.

[0028] If the locking screws are loosened simultaneously, a combined type of rotational adjustment can be achieved. For example, if the first and second locking screws are loosened simultaneously, the beam may move in a reference plane other than the horizontal or vertical plane. Thus, the adjustment can be achieved by using two or three locking screws simultaneously.

[0029] The adjustment tool can be used for different types of support devices. In some applications, only one or two types of rotational movements of the beam are required to achieve effective adjustment of the components in the support device.

[0030] When the adjustment tool of the present invention is used for a support device for positioning a surgical patient (such as bone dislocation correction or tibial intramedullary nailing), usually all three types of adjustments are required, namely the first type of rotational adjustment about the midpoint in the horizontal plane, the second type of rotational adjustment about the midpoint in the vertical plane, and the angular rotational adjustment as the circumferential movement of the beam, to achieve precise adjustment, and even preferably simultaneously. However, even in such cases, sometimes only one or two types of rotational adjustments may be sufficient, which needs to be determined according to the specific situation, such as depending on the body shape and size ratio of the patient.

[0031] The third adjustment shaft can be a two-part shaft, and its components are fixed together by screws. The third adjustment shaft preferably has the form of a ring for attaching it to the support arm of the support device by surrounding the support arm. Due to the two-part design, the adjustment tool can be disassembled and reinstalled from the support arm.

[0032] The support attachment arm of the adjustment tool can move transversely along the beam on both sides of the first adjustment shaft. A fifth locking screw fixes the support attachment arm to a selected position on the beam.

[0033] The transverse movement of the support attachment arm is carried out along at least one groove in the beam by a sliding screw, which holds the support attachment arm in the correct position in the beam and allows it to slide along at least one groove through the spherical part at the end of the sliding screw.

[0034] The support attachment arm has means for coupling it to another component of the support device, such as a wing screw. In the case of a surgical device, the means for coupling the support attachment arm to another component of the support device (such as a traction pin) also includes a fastening plate through which the wing screw passes.

[0035] The adjustment tool can be used for different types of support devices by coupling a third adjustment shaft to the support arm of the support device and coupling the support attachment arm to another component of the support device to achieve the support function.

[0036] The support device of the present invention for bone dislocation correction or tibial intramedullary nail fixation is applicable to these two surgical types.

[0037] When the support device is specifically used for tibial intramedullary nail fixation, the adjustment tool is not necessary and thus removable. Instead, the second attachment arm can be fixed to the frame, and thus the second attachment arm (instead of the support attachment arm) is attached to the end of the traction pin that has passed transversely through the tibia through the guide. For example, this way can be adopted when the adjustment through such a second attachment arm is more convenient than using the adjustment tool.

[0038] However, for bone dislocation correction, it is preferable to use the adjustment tool.

[0039] The support device of the present invention for bone dislocation correction or tibial intramedullary nail fixation includes a first attachment arm for the lower tibial traction pin. The first attachment arm is attached to a transverse support member that is slidably attached between partial longitudinal supports within the frame. The transverse support member slidably attached between the longitudinal supports slides along the longitudinal supports through a guide carriage (such as a traction carriage).

[0040] The longitudinal horizontal supports generally include an upper support and a lower support. In this case, the lower support is preferably used as the slide rail for the guide carriage.

[0041] The device for tibial intramedullary nail fixation further includes a second attachment arm for the upper tibial traction pin. The second attachment arm is attached within the frame to a transverse support member that is fixedly (i.e., immovably) attached between two vertical supports.

[0042] The transverse support members can be rotated forward and backward, which means the attachment arms attached to them can be rotated to the front position and the rear position.

[0043] The guide includes a first detector attached through an attachment device and a second detector attached through an attachment device, respectively for passing the traction pin through the lower and upper parts of the tibia.

[0044] The guide is connected with a vertical height adjustment component. The upper part of the vertical height adjustment component is attached to the same attachment device or a separate attachment element in the guide, and its lower part is attached to a second attachment device. The first detector and the second detector are at different adjustable heights in the same guide.

[0045] All attachment arms (the first attachment arm, the support attachment arm, and possibly the second attachment arm) are attached to the transverse support by means of a loop that surrounds them. The loop includes threaded holes through which screws can be tightened to the bottom of the groove to hold the attachment arms in place.

[0046] The tibial intramedullary nail fixation device according to the present invention (which may be referred to as a tibial traction and reduction device) has been developed for "suprapatellar" (i.e., performed below the patella) tibial intramedullary nail fixation in adult patients.

[0047] In the tibial traction and reduction device according to the present invention, the knee joint is placed at an angle of approximately 5 - 10 degrees, which prevents damage to the nerves at the back of the patient's knee (the "popliteal fossa") during the operation, as there is no pressure on the back of the leg. The device includes needle attachment arms for the upper and lower tibial needles. The attachment arm for the lower tibial needle is located on a slide rail, so that by pulling the attachment mechanism at the lower part, the end of the tibia can be aligned. The attachment arm for the upper tibial needle does not move longitudinally along the device.

[0048] The adjustment tool is designed for its versatility to assist in tibial corrective osteotomy (i.e., corrective surgery of the tibia), as well as connecting an external anchoring device to the tibia, in other words, an external fixation device for keeping the fractured bone stable and aligned. This fixation device can be adjusted externally to ensure that the bone remains in the optimal position during the operation and / or the healing process. The adjustment tool of the present invention can be further improved by connecting it to the distal end (i.e., the ankle end) of the tibial traction and reduction device or the bone dislocation correction device to a horizontal support.

[0049] The adjustment tool of the present invention provides an important improvement for achieving precise results in osteotomy surgeries, including the correction of mid - tibial dislocation or dislocation that does not fully extend to the joint surface. By using the adjustment element of the present invention according to the operation plan formulated after magnetic resonance imaging or original X - ray examination, the correction of the correct angle and rotational abnormality can be achieved.

[0050] The basic function of the adjustment tool is to support the attachment arm to move laterally and synchronously along its fixed beam, and the beam can rotate in different directions. In addition, the correct length of the bone can be achieved by using a guide carriage that slides along the lower support. All these adjustments can be locked in the desired position during the operation, and the operation can be performed by a single surgeon.

[0051] The adjustment tool of the present invention can also be used in a device for correcting congenital bone dislocation. Even for high tibial osteotomy (HTO) of the upper tibia, the device of the present invention provides significant improvements compared to traditional intramedullary tibial nail fixation methods. By using the device of the present invention, the correction of bone dislocation becomes quite easy because the foot can be kept stable during the operation, and the adjustment tool can be adjusted step by step according to the dial, from which it can be directly seen how much the distal tibia needs to be rotated to place the tibia in the correct position.

[0052] The adjustment tool of the present invention can also be used in a device for performing rotational osteotomy, in which the abnormality of the rotational direction of the tibia is corrected. In rotational osteotomy, the tibia is completely cut, and the correct position is achieved by rotating the tibia in the correct direction. In this operation, the adjustment tool of the present invention provides a great advantage because the tibia does not shorten when it is cut, as it is fixed to the device at its proximal and distal ends. By using the adjustment tool of the present invention in the device, very precise correction of rotational abnormality can be achieved because the distal shaft of the adjustment tool rotates thirty degrees.

[0053] In one embodiment of the present invention, the tibia is attached to a tibial traction and reduction device by thin needles. These needles are drilled into the bone from the side of the tibia, the upper and lower parts of the fractured tibia. The advantage of this new device is that the needles are drilled into the already damaged bone, thus avoiding unnecessary damage to intact bone, nerves and tissues.

[0054] In one embodiment of the medical technology device according to the present invention, it allows for a safer and more cost-effective intramedullary tibial nail fixation surgery. In the traditional method, intramedullary tibial nail fixation performed on a pillow requires an additional surgeon to provide sufficient traction to the leg and maintain the leg position during the operation.

[0055] The present invention is described in more detail below by way of an embodiment, related drawings, and the use of this embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] [[ID=1۷]] Figure 1 The adjustment element of the present invention is shown.

[0057] Figure 2 is an example of the support device of the present invention in the form of the device of the present invention for bone dislocation correction or intramedullary tibial nail fixation.

[0058] Figure 3 is Figure 2 a detailed view of a part of DETAILED DESCRIPTION OF THE EMBODIMENT

[0059] Figure 1 The adjustment tool of the present invention is shown. The adjustment tool includes a beam 33, which can be adjusted for different types of rotation or combinations thereof.

[0060] The first adjustment shaft 34 is connected to the beam 33 and is used to rotate the beam about its midpoint in the horizontal plane, that is, to rotate about the vertical axis in the horizontal plane. This rotation is herein referred to as the first rotation. The beam 33 passes through the first adjustment shaft 34. A first locking screw 37 is provided at the top of the first adjustment shaft 34 for adjusting the first rotation by loosening the first locking screw 37. The shaft 34 can be rotated in both the left and right directions and is assisted in adjustment by the graduated scale marked thereon.

[0061] The second adjustment shaft 35 is connected to the first adjustment shaft 34 and is used to rotate the beam 33 about the vertical axis in the vertical plane, that is, to rotate about its midpoint in the vertical plane. This rotation is herein referred to as the second rotation. The second locking screw 38 at the end of the second adjustment shaft 35 can be loosened to adjust the second rotation of the beam 33. The shaft 35 can also be rotated in both the left and right directions and is assisted in adjustment by the graduated scale marked thereon.

[0062] The positioning screw 39 fixed to the second adjustment shaft 35 can be used as an additional safety measure to hold the first adjustment shaft 34 in place.

[0063] The fourth locking screw 40 vertically passes through the first adjustment shaft 34 to fix it to the shaft 33.

[0064] When the screws 39 and 40 are abutted against each other, the respective shafts will not rotate relative to each other. In Figure 1 it can be seen that the adjustment shaft 34 has been rotated approximately 30 degrees to the left relative to the adjustment shaft 35.

[0065] The third adjustment shaft 41 is used to rotate the second adjustment shaft 35 back and forth (or up and down, depending on the viewing angle) and thereby rotate the entire adjustment tool. This causes the beam to perform an angular rotation about the third adjustment shaft 41, and this angular rotation is a circular motion along an arc. A third locking screw 42 is provided for adjusting the rotation of the third adjustment shaft 41, that is, for performing the angular rotation. The shaft 41 can also be rotated in both the left and right directions and is assisted in adjustment by the graduated scale marked thereon.

[0066] The third adjustment shaft 41 is a two-part shaft, and its components are fixed to each other by a screw 43. The third adjustment shaft 41 has the shape of a ring and is used for mounting by surrounding the lateral support arm of the support device, thereby attaching it to the support arm. The third locking screw 42 also attaches the third adjustment shaft 41 to the support arm of the support device of the present invention.

[0067] The first adjustment shaft 34, the second adjustment shaft 35, and the third adjustment shaft 41 are perpendicular to each other. Figure 1 is a perspective view seen from above. The third adjustment shaft 41 can be rotated such that the beam 33 performs a circular motion, and this circular motion is perpendicular to the second adjustment shaft 35 and the first adjustment shaft 34.

[0068] There is a pair of support attachment arms 36 such that there is one support attachment arm 36 on each side of the first adjustment shaft 34 that moves laterally along the beam 33. In Figure 2 , the lower end of the support attachment arm 36 is configured to surround the shaft 33. Alternatively, the end of the arm may be provided with a slot or slit for internal movement. The fifth locking screw 44 fixes the attachment arm 36 to a selected position on the beam 33.

[0069] The lateral movement of the attachment arm 36 is effected by a sliding screw 46 along at least one groove 45 in the beam 33. The sliding screw 46 holds the support attachment arm 36 in the correct position in the beam 33 and allows it to slide along at least one groove 45 by means of a ball at the end of the sliding screw 46.

[0070] The attachment arm 36 has means for coupling it to another part of the support device, such as a wing screw 47, for coupling to a traction pin of a bone dislocation correction device or an intramedullary tibial nail fixation device. The means for coupling the support attachment arm 36 to another part of the support device also includes a fastening plate 48 through which the wing screw 47 passes.

[0071] Figure 2 is an example of the support device of the present invention in the form of the traction and reduction device of the present invention for intramedullary tibial nail fixation. This device is used for bone dislocation correction or tibial traction and reduction for intramedullary tibial nail fixation, in which an intramedullary nail is inserted into the tibia.

[0072] When a patient has a tibial fracture due to trauma, it is treated by inserting an intramedullary nail into the tibia, and the intramedullary nail will remain therein if required for the repair of the tibia.

[0073] This is the case if the bone breaks into two or more parts and the fracture does not extend to the articular surface.

[0074] [[ID=2P]]The patient (not shown) lies supine on an operating table (not shown) throughout the operation. The patient is anaesthetized before the operation. The patient is then covered with a sterile drape, exposing the leg to be operated on.

[0075] The device according to the present invention has a rectangular base 1. The base 1 is a bottom plate, which is a rectangular plate with a central opening to allow imaging, so that when imaging the leg from above, there is no metal within the imaging area. The function of the base 1 (i.e., the bottom plate) is to stabilize the device and prevent the device from pressing into the soft mattress of the operating table. The vertical support member 2 can be attached to the base 1.

[0076] Two upper supports 4 are attached to a total of four vertical supports 2 (at each corner of the base 1) by knurled head screws 19, and their height is approximately the height of the tibia when the knee joint is elevated to an angle of about 10 degrees. The two upper supports 4 are attached to both sides of the base 1 by extending across the longitudinal sides of the base 1. In addition, two lower supports 3 that extend across the longitudinal sides of the base 1 are approximately connected to the ankle height.

[0077] Transverse supports 5, 5', 5" and 6 (attached to the vertical support 2 by screws 15, for example, approximately at the ankle height) are connected to the other two sides of the base 1 by extending across the short sides of the base 1. The device also includes a transverse support 6' located between the lower supports 3, which moves along the lower supports 3 through a guiding carriage 8 such as a traction carriage. Therefore, the lower supports 3 are configured as the slide rails of the guiding carriage 8 and support the device.

[0078] The vertical supports 2, upper supports 4, lower supports 3, and transverse supports 5, 5', 5", 6 and 6' can be, for example, guide rails, tubes or rods or corresponding supports or shafts.

[0079] In Figure 2 , the lowest transverse supports 5' and 5" are at a slightly lower height than the lower supports 3, while the transverse supports 5 and the transverse support 6 are at a slightly higher height than the lower supports 3. For ease of illustration, the transverse support 6 is drawn in a discontinuous manner in Figure 2 to more clearly show how the first attachment arm 24 is attached to it, which will be further described below. The transverse support 6 is a control shaft, and its function will be explained below. In Figure 2 , the transverse supports 5, 5', 5" and 6 are attached to the vertical support 2 by fastening screws 15 or other attachment means. The holes (not labeled with reference numerals) on the vertical support 2 serve to reduce weight because the vertical support 2 is heavier. The transverse supports 5, 5', 5" and 6 are in fixed positions, while the transverse support 6' moves along the lower supports 3 as described above.

[0080] The device according to the present invention is placed under the leg to be operated on in the following manner: The patient lies on their back, and the leg to be operated on faces the axis 5.

[0081] After that, the leg to be operated on still needs to be accurately or more accurately positioned on the device to stabilize the fractured bone.

[0082] For stabilization, so-called traction pins are drilled into the tibia from the side, respectively at the upper part of the tibia (near the patella, at the position below the patella) and the lower part of the tibia (at the ankle). The traction pins are drilled into the tibia through a guide attached to the upper support 4, and the guide 21 moves along another upper support 4.

[0083] The traction pin will be removed before closing the surgical wound after the operation. However, before drilling the traction pin, it is necessary to ensure that the guide 21 for drilling the traction pin is in the correct position relative to the bone in both the vertical and transverse directions. The position of the guide 21 is checked by an X-ray machine and adjusted if necessary.

[0084] The guide 21 moves unobstructed from the ankle to the knee in the upper support 4 and includes independent transverse arms 11, 13 of different heights, which serve as detectors for positioning the traction pin. These transverse arms 11, 13 are direction-controlled and not intended to rotate, so their shape is preferably non-circular (e.g., square) to better lock them to the sleeve in the transverse direction to prevent rotation.

[0085] Positioning of the first traction needle

[0086] The guide 21 includes a first sleeve 25 through which the first transverse arm 11 passes and extends perpendicular to the upper support 4. At the end of the transverse arm 11, the traction pin 20 is in position A, where its transverse position is adjusted. When the traction pin 20 is in position A in the sleeve 30 at the end of the transverse arm 11, it is marked as 20A. The transverse arm 11 serves as the upper detector for the upcoming traction pin 20. The function of the transverse arm 11 (i.e., the upper detector) is to adjust the transverse position of the guide 21, which is done by fluoroscopy from above. At this time, the traction pin 20 has not actually been drilled into the tibia at position A.

[0087] The guide 21 includes a second sleeve (located on the other side of the guide 21 and not visible), through which the height adjustment member 12 passes, and the second sleeve is located above the height adjustment member 12. The height adjustment member 12 can adopt a rod-like structure or a similar structure. At the lower part of the height adjustment member 12, there is a third sleeve 10 through which the height adjustment member 12 of the guide 21 passes. Therefore, the height adjustment member 12 combines the lower detector with the upper detectors (i.e., the transverse arms 11 and 13).

[0088] The second transverse arm 13 passes through the sleeve 10 and extends perpendicular to the upper support 4, and the traction pin 20 is attached to the second transverse arm 13 through a connecting member 31 including a sleeve 23. In other words, the traction pin is transferred from the transverse arm 11 to the transverse arm 13. The transverse arm 13 serves as the lower detector for the same traction pin 20, which was previously used to check its position relative to the upper articular surface of the tibia (i.e., to check its transverse position) and was then transferred to the sleeve 23 of the transverse arm 13.

[0089] Therefore, after adjusting the lateral direction of the guide 21, the same traction pin 20 will pass through the sleeve 23 of the lower detector. After confirming the correct height of the traction pin 20 through lateral fluoroscopy, it will be further drilled into the upper or lower part of the tibia. It should be further emphasized that once fluoroscopy is performed on the leg from above and it is confirmed that the traction pin 20 will not penetrate the joint surface and remains below the joint surface, the traction pin 20 is transferred from the upper detector to the lower detector. When viewed from above, the upper detector and the lower detector are aligned vertically; when viewed from the side, the above detectors are also aligned with each other.

[0090] When the position of the guide 21 is confirmed to be correct, the traction pin 20 can be drilled into the bone. Usually, the lengths of the traction pin exposed on both sides of the leg are equal. To drill into the bone, the traction pin 20 needs to be first attached to an independent hand drill (not shown), and then drilled into the tibia through the sleeve 23 - at this time, the guide 21 (and the sleeve 23) has been set to the correct height relative to the tibia through the height adjustment member 12. Fluoroscopy from above can show the distance between the traction pin and the joint surface.

[0091] When the traction pin 20 is drilled into the bone and is in position B, it is marked as 20B. Therefore, position B represents the traction pin 20B that has been drilled into the interior of the bone. The positioning order of the traction pin 20 does not matter, but usually the traction pin in the upper part of the tibia is positioned first. Therefore, in this embodiment, it is assumed that the traction pin 20 is first drilled into the upper part of the tibia.

[0092] Both ends of the traction pin 20 in the thigh are respectively attached to the corresponding first attachment arm 24 through wing screws 16' and clamps 14', and at this time the leg forms a small angle of about 10 degrees. The first attachment arm 24 is attached to the fixed lateral support member 6 through a ring 27, and the lateral support member 6 passes through the ring 27. Alternatively, the lower end of the first attachment arm 24 can be configured (such as bent) to surround the lateral support member 6.

[0093] The first attachment arm 24 is attached to the lateral support member 6 through the ring 27, enabling it to rotate back and forth. When the screw 18 is loosened, the attachment arm 24 rotates together with the lateral support member 6. Therefore, when installing the traction pin for the patient, the first attachment arm 24 can be rotated to the rear position to avoid the operation area.

[0094] During installation, if the knurled head screw 32 is loosened, the first attachment arm 24 can also move slightly laterally along the lateral support member 6. A groove 7 is provided on the outer surface of the lateral support member 6 (at the knee end, that is, the end of the thigh), and the groove is located on the inner or outer side of the device.

[0095] The function of the groove 7 is to enable the first attachment arm 24 to be locked in a position close to the skin by tightening a screw (such as the knurled head screw 32), so as to attach the traction pin 20 to the first attachment arm 24. In other words, first move the attachment arm 24 close to the skin, and then lock it in the transverse groove 7 on the outer surface of the transverse support member 6 by the knurled head screw 32. The groove 7 can prevent the first attachment arm 24 from rotating because a part of the tightened screw is located at the bottom of the groove 7. Without the groove 7, fastening the first attachment arm 24 on the circular surface of the transverse support member 6 may cause it to rotate.

[0096] Positioning of the second traction needle

[0097] In this embodiment, the positioning operation of the second traction pin (positioned at the lower part of the tibia) is completed using the same guide 21 as the first traction pin 20 (positioned at the upper part of the tibia).

[0098] After the longitudinal position of the second traction pin is adjusted by the upper detector 11 (in the same way as the first traction pin), the second traction pin is positioned at the end of the transverse arm 13, which serves as the lower detector, through the connector 31 and the sleeve 23 inside it.

[0099] The second traction pin is drilled into the lower part of the tibia at the ankle in the same way as the first traction pin 20 is drilled into the upper part of the tibia.

[0100] Since Figure 2 the first traction pin 20 drilled into the upper part of the tibia is shown, the second traction pin is not separately labeled with a reference number, but Figure 2 the same also applies to the positioning scenario of the second traction pin, with the only difference being that the first traction pin 20 is replaced by the second traction pin.

[0101] Both ends of the traction pin in the calf are attached to the corresponding support attachment arm 36 through the wing screws 47 and the clamp or fastening plate 48 respectively. The support attachment arm 36 is a component of the adjustment element of the present invention, and its details are further shown in Figure 1 this

[0102] The adjustment tool is attached to the movable transverse support member 6' when the leg is at a small angle of about 10 degrees.

[0103] The adjustment tool is detachable and can be removed from the device; at this time, the traction pin in the calf can be attached to the second attachment arm 22 instead of the support attachment arm 36.

[0104] In this case, both ends of the traction pin in the calf are attached to the corresponding second attachment arm 22 through the wing screws 16 and the clamp 14 respectively, and the second attachment arm 22 is attached to the movable transverse support member 6' when the leg is at a small angle of about 10 degrees.

[0105] The second attachment arm 22 is attached to the transverse support 6' by a loop 27, enabling it to rotate back and forth. When the screw 28 is loosened, the second attachment arm 22 rotates together with the transverse support 6'. Thus, when installing the traction pin for the patient, the second attachment arm 22 can be rotated to the rear position to avoid the operation area. The back-and-forth rotation of the second attachment arm 22 can be adjusted by a screw 17 through which the transverse support 6' can rotate.

[0106] When the knurled screw 32 is loosened, the second attachment arm 22 can also move slightly laterally along the transverse support 6'.

[0107] To position the traction pin (i.e., the traction pin for the calf), first move the second attachment arm 22 close to the skin and then lock it in a groove 7 on the outer surface of the transverse support 6' that moves along the lower support 3 by the knurled screw 32. At the ankle end (i.e., the calf end), the groove is located at an outward position on the outside of the device.

[0108] Once the traction pin is positioned, turn the screw 17 to the forward position and lock it by the knurled screw 32.

[0109] The following discloses some additional key points.

[0110] Generally, if the knurled screw 32 is loosened, when the traction pin 20 is attached to the first and second attachment arms 22 or 24, or attached to the first attachment arm 24 and the support attachment arm 36, the first and second attachment arms 22 or 24 and the support attachment arm 36 can move laterally on the shafts 6 or 6' simultaneously. After the traction pin 20 is attached, the rods 6, 6' and the first and second attachment arms 22, 24 and the support attachment arm 36 shall not move back and forth under any circumstances. If the knurled screw 32 is too loose and disengages from the groove 7, the first and second attachment arms 22, 24 and the support attachment arm 36 may rotate freely about the shafts 6, 6', which must be avoided.

[0111] The long upper supports 4 at the uppermost part of the device longitudinally serve to stabilize the device. They can also be used to support the leg, for example, during the actual intramedullary nailing procedure or when positioning the traction pin at the very beginning of the operation using an X-ray fluoroscopy drape for support. Using an X-ray fluoroscopy drape for support means that, for example, the two ends of the drape can be attached to the upper supports 4 by drape clamps (one end attached to one upper support 4 and the other end attached to the other). In this way, when positioning the traction pin, the leg can be placed on the drape without additional support.

[0112] Generally, the height of the upper support 4 is deliberately set slightly higher than the height when the traction pin attachment arm is in the forward position. This is to avoid the upper support 4 blocking the imaging area during lateral X-ray fluoroscopy of the leg.

[0113] The guide 21 used at the start of the operation is also attached to the upper support 4. The guide 21 slides unimpeded on the upper support 4 from the knee to the ankle. The guide 21 is always attached to the outermost long upper support 4 on the outside of the leg to be operated on. The traction pin is drilled into the tibia through the sleeve of the guide 21 and thus is always positioned within the outermost upper support 4. The guide 21 has two functions: an upper detector 11 and a lower detector 13. The upper detector 11 includes a transverse rod 30 with a hollow structure at its rod end that allows the traction pin to be placed at the rod end. The upper detector 11 shows, with the aid of the traction pin through an X-ray device, the distance between the traction pin and the joint surface, i.e., an X-ray is taken from above the leg. The lower detector 13 is used to observe, through an X-ray device from the side of the leg, the correct height of the traction pin. The lower detector 13 also includes a guide sleeve 23 through which the same traction pin first used in the upper detector is drilled into the bone. The lower detector also includes a height adjustment member 12 (such as a vertical rod) by which the height of the sleeve relative to the bone can be adjusted. When viewed from above, the two functional parts, the upper detector and the lower detector, are clearly aligned with each other.

[0114] When the intramedullary nail is positioned in the tibia, the upper support 4 can be removed from the device, but this is not necessary. The device can be designed such that the upper support 4 does not interfere with the operation when the fastening screws are installed onto the intramedullary nail.

[0115] In addition to the stabilizing device, the long lower support 3 also serves as a slide rail for the guide carriage 8 (or traction carriage) at the ankle end. This carriage can apply an appropriate traction force to the leg to align the bone ends and lock the guide carriage 8 to the lower support 3 to prevent it from moving on its own.

[0116] The lower transverse supports 5' and 5” are so-called fixed transverse supports that can be removed if necessary, but their function is to stabilize the device. The two first attachment arms 24 of the traction pin are integrally attached to the upper transverse support 6. Milling grooves are also provided at both ends of the transverse support 6 of the first attachment arm 24, which means that when using the detector 13 to position the traction pin in the patient's body, the transverse support 6 can be rotated to a rear position. Once the positioning of the traction pin is completed, the transverse support 6 is rotated to the front position and locked by a knurled head screw 18 to prevent the first attachment arm 24 from swinging.

[0117] The guiding carriage 8 (i.e., the traction carriage) moves unobstructed from the ankle end to the knee end on the lower support 3. The guiding carriage 8 is equipped with a bushing / sleeve (not labeled with a reference number) for each lower support 3 through which the lower support 3 passes, and the sleeve is provided with some locking screw (not labeled with a reference number) by which the guiding carriage 8 can be locked to the desired position on the lower support 3. Above the lower sleeve through which the lower support 3 passes, there is an independent attachment mechanism for the transverse support of the traction needle attachment arm, and this mechanism is attached to the lower sleeve. The function of the first attachment arm 24 of the ankle traction needle is the same as the knee attachment method, that is, the first attachment arm 24 can be locked to the forward position, and the transverse support 6 is provided with a groove 7, so that the first attachment arm 24 of the traction needle can move in the transverse direction and be locked in the desired position within the groove 7 by a knurled head screw.

[0118] The upper support 4 is usually about 5 - 7 cm higher than the traction needle that is drilled into the tibia and attached to the first and second attachment arms 22, 24 or the first attachment arm 24 dedicated to the traction needle and the support attachment arm 36. Since the thickness of the tibia of adult patients is relatively constant and the traction needle is usually drilled into the center of the bone, the leg size does not affect this height setting. The upper support 4 thus never obscures the imaging area. The height of the ankle is at the same level as the second attachment arm 22 or the support attachment arm 36.

[0119] The transverse support 6' is designed to move along the lower support 3 in order to apply traction to the leg and position it on the lower support 3 at a position where the leg is in the correct traction state. For this purpose, the second attachment arm 22 or the support attachment arm 36 of the lower tibia traction needle is located on the slide rail by the transverse support 6', so that by pulling the lower attachment mechanism, the broken ends of the tibia fracture can be aligned.

[0120] By aligning the bone ends of the fracture site (for example, using an X - ray dressing), the leg is tractioned longitudinally and re - positioned transversely. The X - ray dressing is a non - lint cloth containing a small piece of wire inside. The role of the wire in the cloth is (if these cloths are used in surgeries placed inside the human body) to find the cloth through X - ray imaging with the help of the wire, otherwise it is actually impossible to find the cloth covered by blood. The cloth is about 40 cm long and about 30 cm wide when unfolded. These cloths can also be used to assist in fixing the traction needle by placing the cloth transversely on the upper support 4 so that the leg is supported on the cloth. In this way, there is no need for additional support for the leg when positioning the traction needle, and the leg can better maintain a fixed position.

[0121] The inner hole of the ring 27 of the lateral support 6' is threaded. When the knurled head screw 32 is tightened to the bottom of the groove, the first and second attachment arms 22, 24 and the support attachment arm 36 can be fixed in place; when the screw is loosened, the first and second attachment arms 22, 24 or the first attachment arm 24 and the support attachment arm 36 can move synchronously again. Since the screw 32 is located within the groove rather than against a circular surface, this also prevents the attachment arms 22, 24, 36 from rotating downward due to the weight of the leg. Similarly, the ring 27 in the lateral support 6 is provided with Figure 1 a knurled head screw (not shown) which is used for fastening in a corresponding manner.

[0122] Figure 3 is Figure 2 a detail view of a certain part of.

[0123] Once the traction pin 20 is positioned, the actual intramedullary nail fixation operation can be carried out:

[0124] - Next, the surgeon makes an incision above the patella, and the instrument for incision is inserted into the interior of the tibia from below the patella.

[0125] - First, a tissue protector is placed below the patella to prevent the instrument from damaging tissues and other important areas unrelated to the surgery. All instruments required for the surgery, except the intramedullary nail, are inserted into the tibia through the tissue protector.

[0126] - Next, a slightly larger drill bit is used to drill an entrance in the bone, with a longitudinal depth of about 4 cm along the bone

[0127] - Then a guide wire reaching up to the ankle is inserted into the bone, with a diameter of about 2 - 3 mm. The guide wire is used because the drill bit for drilling out the bone marrow obstructing the intramedullary nail is hollow, and the guide wire can pass through the drill bit to prevent the drill bit from penetrating the tissues at the fracture site and causing damage.

[0128] - Thereafter, the bone marrow is gradually drilled out from the interior of the bone ("reaming") by replacing the drill bit with a diameter 1.5 mm larger each time after drilling, until enough space is left for the intramedullary nail.

[0129] - Subsequently, the intramedullary nail is inserted into the bone with the assistance of the guide wire.

[0130] - When the intramedullary nail is placed in the bone, the guide wire is removed, and the upper lateral support 4 can be removed from both sides of the device if desired.

[0131] - At this time, the intramedullary nail is fixed in the patient's body using screws. Then, if desired, the upper support 4 can be removed, after which the leg can be detached from the first and second attachment arms 22, 24 or the support attachment arm 36 dedicated to the traction pin, the traction pin is cut from the side close to the skin, and it is pulled out of the patient's body using flat-nose pliers.

[0132] - After these steps are completed, suture the incision and cover it with a wound dressing.

Claims

1. An adjustment tool for a support device, the adjustment tool comprising a first adjustment shaft (34), a second adjustment shaft (35) and a third adjustment shaft (41), and a cross beam (33) whose rotational movement in at least one direction can be adjusted by at least one of the adjustment shafts (34, 35 and / or 41). The first adjustment shaft (34) is attached to the cross beam (33). The second adjustment shaft (35) is attached to the first adjustment shaft (34), and the third adjustment shaft (41) is attached to the second adjustment shaft (35). The adjustment tool further comprises a pair of attachment arms (36), wherein the attachment arms (36) are laterally movable along the cross beam (33) on both sides of the first adjustment shaft (34).

2. The adjustment tool according to claim 1, wherein the first adjustment shaft (34), the second adjustment shaft (35) and the third adjustment shaft (41) are perpendicular to each other.

3. The adjustment tool according to claim 1 or 2, wherein the first adjustment shaft (34), the second adjustment shaft (35) and the third adjustment shaft (41) can be rotated relative to each other simultaneously or separately by locking screws (37, 38, 42) in their respective adjustment shafts (34, 35, 41).

4. The adjustment tool according to any one of claims 1-3, wherein the rotational movement comprises a first rotation of the cross beam (33) about its midpoint in a horizontal plane, whereby a first locking screw (37) for the first rotation adjustment is provided in the first adjustment shaft (34).

5. The adjustment tool according to any one of claims 1-4, wherein the rotational movement comprises a second rotation of the cross beam (33) about its midpoint in a vertical plane, whereby a second locking screw (38) for the second rotation adjustment is provided in the second adjustment shaft (35).

6. The adjustment tool according to any one of claims 1-5, wherein the rotational movement comprises an angular rotation of the cross beam (33) along an arc determined by the distance between the third adjustment shaft (35) and the cross beam (33), whereby a third locking screw (42) for the third rotation adjustment is provided in the third adjustment shaft (35).

7. The adjustment tool according to any one of claims 1-6, further comprising a positioning screw (39) fixed to the second adjustment shaft (35) to fix the first adjustment shaft (34) in place as an additional safety measure.

8. The adjustment tool according to any one of claims 1-7, further comprising a fourth locking screw (40) passing vertically through the first adjustment shaft (34) to fix it to the cross beam (33).

9. The adjustment tool according to any one of claims 1-8, wherein the third adjustment shaft (41) is a two-part shaft, and its components are fixed to each other by screws (43).

10. The adjustment tool according to any one of claims 1-9, wherein the attachment arms (36) are laterally movable along the cross beam (33) on both sides of the first adjustment shaft (34), and a fifth locking screw (44) is provided to fix the attachment arms (36) to a selected position on the cross beam (33).

11. The adjusting tool according to any one of claims 1-10, wherein the lateral movement of the attachment arm (36) is effected by a sliding screw (46) along at least one groove (45) in the cross beam (33), and a sphere at the end of the sliding screw (46) is used to hold the attachment arm (36) in the correct position on the cross beam (33) and to allow it to slide along the at least one groove (45).

12. The adjusting tool according to any one of claims 1-11, wherein the third adjusting shaft (41) is annular and is used to attach it to a support arm of the support device by surrounding the support arm of the support device.

13. The adjusting tool according to any one of claims 1-12, wherein the attachment arm (36) is provided with means for coupling to another component of the support device, such as a wing screw (47).

14. The adjusting tool according to claim 13, wherein the means for coupling the attachment arm (36) to another component of the support device further comprises a fastening plate (48) through which the wing screw (47) passes.

15. A support device having a component to be positioned and supported, the support device comprising an adjustment tool according to any one of claims 1-14, the adjustment tool being coupled on the one hand to its lateral support arm and on the other hand to the component to be supported; wherein, The adjusting tool comprises a first adjusting shaft (34), a second adjusting shaft (35) and a third adjusting shaft (41), and a cross beam (33) capable of adjusting at least one directional rotational movement through at least one of the adjusting shafts (34, 35 and / or 41); the first adjusting shaft (34) is attached to the cross beam (33), the second adjusting shaft (35) is attached to the first adjusting shaft (34), and the third adjusting shaft (41) is attached to the second adjusting shaft (35); the adjusting tool further comprises a pair of attachment arms (36), wherein the attachment arms (36) are laterally movable along the cross beam (33) on both sides of the first adjusting shaft (34).

16. The support device according to claim 15, wherein the support device is a support device for positioning a surgical patient, such as for correcting bone dislocation or tibial intramedullary nailing.

17. The support device for correcting bone dislocation or tibial intramedullary nailing according to claim 16, comprising: A frame structure composed of vertical supports (2), longitudinal supports (3, 4) and transverse horizontal supports (5, 5', 5", 6, 6'); A traction needle (20) to be passed through the tibia; A guide (21) slidably coupled to the longitudinal horizontal support (4) of the support device and comprising: - A first detector (11) for adjusting the lateral position of the traction needle (20) relative to the upper articular surface of the tibia; - A second detector (13) for adjusting the vertical position of the traction needle (20) and passing the traction needle (20) transversely through the tibia; A first attachment arm (24) configured to be attached to one end of the frame and attaching the end of the traction needle (20) passing through the tibia to the frame through the guide (21); It is characterized in that it further includes an adjusting tool according to any one of claims 1-14, the adjusting tool being coupled to a horizontal support member (6') that is slidably attached between longitudinal support members in the frame, the horizontal support member being located at the other end of the frame opposite to the first attachment arm (24); the adjusting tool includes a first adjusting shaft (34), a second adjusting shaft (35) and a third adjusting shaft (41), and a cross beam (33) whose rotational movement can be adjusted by at least one of the adjusting shafts; the first adjusting shaft (34) is attached to the cross beam (33), the second adjusting shaft (35) is attached to the first adjusting shaft (34), and the third adjusting shaft (41) is attached to the second adjusting shaft (35); the adjusting tool further includes a pair of attachment arms (36) that can move laterally along the cross beam (33) on both sides of the first adjusting shaft (34).

18. The device according to claim 17, wherein when the device is used for tibial intramedullary nail fixation, it further includes a second attachment arm (22) that is configured to be attached to the frame so as to replace the support attachment arm (36), and the end of a traction needle (20) that laterally penetrates the tibia is attached to the frame through a guide (21); wherein the third adjusting shaft (41) is a two-part shaft, and its components are fixed to each other by screws (43) for easy disassembly of the adjusting element.

19. The device according to claim 17 or 18, wherein the lateral support member (6') that is slidably attached between the longitudinal support members slides along the longitudinal support members through a guide carriage (8), and the longitudinal horizontal support member includes an upper support member (4) and a lower support member (3), and the lower support member (3) serves as a slide rail for the guide carriage (8).

20. The device according to claim 19, wherein the angular rotation of the cross beam (33) can be achieved through the guide carriage (8) via a slidable lateral support member (6') fixed to the third adjusting shaft (41).

21. The device according to any one of claims 17-20, wherein the lateral support members (6', 6) are configured to be rotatable back and forth, which means that the attachment arms (36, 22 and 24) attached thereto can be rotated to the front position and the rear position.

22. The device according to any one of claims 14-21, wherein the attachment arms (36, 22, 24) are attached to the lateral support members (6', 6) by a ring (27, 27') that surrounds the lateral support members (6', 6) or by the ends that surround the lateral support members (6', 6); the ring (27, 27') or the ends include threaded holes, and screws (44, 32) can be tightened through the threaded holes to the bottom of the groove to fix the attachment arms (36, 22, 24) in place.

Images