TPU Distal Interphalangeal Joint Immobilization Orthosis for Heberden's Nodes

Abstract

We provide a TPU distal interphalangeal joint fixation brace for Heberden's nodes. Solution: The brace is made of TPU, a flexible yet non-stretchable material with a hardness that allows for sufficient fixation even when thin, and features a flat-cut design that allows it to be rolled into a cylindrical shape. To ensure the brace can be worn even when the joint is severely swollen, deformed, or tender, the bands are positioned so that the edge of distal band 1 is aligned with the nail cuticle line, and proximal band 2 secures the center of the middle phalanx. The band is placed on the finger through the two holes on the opposite end, and the length is adjusted to fit the finger's thickness. By inserting the end of the band into the third hole, the end of the band is stored inside the brace and secured by friction. The brace can be converted from flexible mode, which allows slight movement, to fixed mode, which allows complete fixation, by simply rotating and pushing the brace.

Description

[Technical Field]

[0001] The purpose of this invention is to create an orthosis for immobilizing the distal interphalangeal joint (hereinafter referred to as DIP joint) that has a flat-cut design using a harder TPU material, is lightweight, causes less pain when worn, and can be used for water work. [Background technology]

[0002] Conservative treatment for Heberden's nodes generally recommends immobilization with taping. Wrapping a joint with non-elastic tape provides firm immobilization, is almost weightless, and can be expected to produce good results in terms of pain reduction. However, taping has problems with irritation and durability. Commercially available taping products come in a variety of materials, including tape, silicone, hook-and-loop fasteners, and tin. Tape-based products have problems with irritation and durability, while silicone products have problems with fixation strength, thickness, and inability to adjust. Hook-and-loop fasteners also have problems with water work, fixation strength, and thickness. Tin products also have problems with slipping off, being heavy, thick, and expensive.

[0003] A tape product for Heberden's nodes is reported in JP 2022-184605, a supporter made of elastic material is reported in JP 2015-177941, and a tin product is reported in JP 2017-205314. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-184605 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-177941 [Patent Document 3] Japanese Patent Application Publication No. 2017-205314 Summary of the Invention [Problem to be solved by the invention]

[0005] The purpose of this project is to create an orthosis that has high fixation while leaving enough play for the DIP joint so that it does not interfere with daily life activities, has adjustable thickness according to the degree of deformity, is durable, lightweight, thin, and can be used for wet work. [Means for solving the problem]

[0006] (1) It is made of a flexible but non-stretching material, TPU, which is thin but hard enough to provide sufficient fixation, and is designed with a flat cut that becomes cylindrical when rolled up. (2) To ensure that the brace can be worn even when the distal interphalangeal joint is severely swollen and deformed, and there is tenderness, the position of the band is adjusted so that the edge of the distal band is aligned with the line of the nail cuticle, and the proximal band fixes the central part of the middle phalanx. (3) With the band passing through the two holes on the opposite end, adjust the length to fit the thickness of the finger, and insert the end of the band into the third hole. The end of the band will then be stored inside the brace, and the band will be secured in place by friction. (4) Holes are drilled in the pads of the fingers to reduce sweating, the pads of the fingers are shifted proximally so that the band does not catch on the fingertips, and the band is designed with a gentle curve to reduce pain when flexion force is applied to the distal interphalangeal joints. (5) In some daily activities, necessary movements cannot be performed unless there is some freedom of movement (a state with some play), and pain cannot be alleviated unless the distal interphalangeal joint is completely fixed. The brace is designed to enable mode conversion from a flexible mode, which allows some movement, to a fixed mode, which is completely fixed, simply by rotating and pushing the brace. This invention solves the problem by designing it with the features (1) to (5). [Effects of the Invention]

[0007] The use of this TPU distal interphalangeal joint fixation device for Heberden's nodes is expected to reduce pain from Heberden's nodes and is also useful for long-term fixation of tendon-related mallet finger. Furthermore, the characteristics of the material and design are expected to provide the following benefits (1) to (5). (1) By using TPU, a flexible yet non-stretchable material, the brace can maintain sufficient fixation even when fabricated at a thickness of 0.6 mm (72D hardness). The 0.6 mm thickness is almost the same as wrapping tape around the finger several times, minimizing inconvenience during daily activities. Furthermore, TPU does not absorb moisture, making it suitable for wet work and reducing skin irritation such as tape rash. While tape requires re-wrapping every few days, TPU braces are durable, tough, and long-lasting, making them cost-effective. The flat-cut design, which forms a cylindrical shape when rolled, reduces printing errors and costs when fabricated using a 3D printer. Mass production also significantly reduces manufacturing costs. (2) In the early stages of Heberden's nodes, the finger remains cylindrical with little change in thickness. However, as the disease progresses to the advanced and advanced stages, repeated inflammation causes osteophytes to grow, resulting in thickening, swelling, and deformation of the DIP joint. To ensure the orthosis can be worn even when the DIP joint is thickened, the distal band's edge is aligned with the nail cuticle line, and the proximal band is designed to secure the central part of the middle phalanx. Even as Heberden's nodes progress from the advanced to advanced stages, the nail does not thicken, so tightening the band does not compress the painful area, reducing pain during wear. Furthermore, by designing the proximal band to be positioned at the central part of the middle phalanx, where the orthosis is at its thinnest, good fixation can be achieved without the orthosis slipping or rotating. (3) The band is designed for simple fixation and allows for adjustment of length to fit the finger thickness by passing it through three holes. The size is adjusted by passing the non-hole band through the first and second holes from the end of the band with the opposite hole, and then passing it through the third hole to secure it. Because the end of the band passes through the third hole and enters the inside of the brace, the end of the band does not come into contact with adjacent fingers or get in the way while wearing the brace. Furthermore, in patients with advanced to late-stage Heberden's nodes whose DIP joints are thick, even if you try to put the brace on from the tip like putting on a ring, the thick part will get caught and make it difficult to put on. It can be used even in cases of severe deformity by loosening the proximal band, adjusting the position, and then tightening the proximal band to secure it. (4) Because TPU is not breathable, holes were drilled in the finger pads to reduce stuffiness even during extended use. Furthermore, because the fingertips are sensitive, the finger pads were shifted proximally to minimize contact with the fingertips, and a gentle curve was designed to reduce pain when the DIP joint is bent. This reduces discomfort when worn and allows for extended use. (5) When performing daily activities that require delicate fingertip movements, such as using chopsticks or writing with a pen, some movements may not be possible unless there is some movement (with some play), or strong force is applied to the fingers, and pain may not be alleviated unless the DIP joint is completely immobilized. The band needs to be adjusted depending on the condition, and it would be convenient if it could be easily switched between complete immobilization and a state with some play. The size and shape of the orthosis were adjusted so that complete immobilization could be achieved simply by rotating the orthosis and pushing it proximally. The size variation was designed to include seven sizes, with M being 100% and expanding by 5% from 3S to 3L. In flexible mode, which allows for slight movement, confirm that 1) the edge of the distal band and the nail cuticle are aligned, 2) the distal interphalangeal skin line passes through the center of the fenestration, and 3) there is little space between the distal band and the nail.In fixed mode, which fixes the DIP joint in the middle position, confirm that 1) the edge of the distal band and the articular surface of the DIP joint are aligned, 2) the distal interphalangeal skin line passes through the center between the bands, and 3) there are no gaps between the distal band and the finger pad, and then select the size.Using the appropriate size makes it easy to change modes. [Brief explanation of the drawings]

[0008] [Figure 1] This shows the flexible and fixed modes of the TPU distal interphalangeal joint fixation brace for Heberden's nodes of the present invention. [Figure 2] This is a plan view of a TPU distal interphalangeal joint fixation brace for Heberden's nodes (thickness: 0.6 mm). [Figure 3] This is the assembled state of the TPU distal interphalangeal joint fixation brace for Heberden's nodes. [Figure 4] This is a size variation of a TPU distal interphalangeal joint fixation brace for Heberden's nodes. [Figure 5] This is a size selection chart for a TPU distal interphalangeal joint fixation brace for Heberden's nodes. [Figure 6] This is a procedure for wearing a TPU distal interphalangeal joint fixation brace for Heberden's nodes. [Figure 7] This is an explanatory diagram of mode conversion for a TPU distal interphalangeal joint fixation orthosis for Heberden's nodes. [Figure 8] This is how to check the position and size of the device when it is attached in flexible mode. [Figure 9] This is the range of motion of the PIP joint in flexible mode. [Figure 10] This is how to check the position and size of the device when it is attached in fixed mode. [Figure 11] This is the range of motion of the PIP joint in fixed mode. DETAILED DESCRIPTION OF THE INVENTION

[0009] Explain how to use it. To select the size, measure the distance from the nail cuticle to the distal interphalangeal skin line. There are seven sizes available, ranging from 8mm to 14mm in 1mm increments, and seven sizes are available, ranging from 3S to 3L. In practice, adjust one size up or down to fit the thickness of your finger. [Example]

[0010] An embodiment will now be described with reference to the accompanying drawings. (1) Basic design (Figures 2 and 3): A 0.6 mm thick, flat-cut design that can be rolled into a cylindrical shape, with a band fixed at the distal and proximal sides of the DIP joint. The band's length can be adjusted through three holes, and holes are drilled in the finger pad to reduce sweating, and the finger pad is shifted proximally to prevent the band from hanging over the fingertip. (2) Size variations (Fig. 4): With M being 100%, seven sizes were designed, from 3S to 3L, each size being 5% smaller or larger. (3) Size selection (Figure 5): Measure the distance from the nail cuticle to the distal interphalangeal skin line. There are seven sizes available, ranging from 8mm to 14mm in 1mm increments, and seven sizes are available, ranging from 3S to 3L. In practice, adjust the size up or down by one size to fit the thickness of your finger. (4) How to wear (Figure 6): 1) Loosen the band and place the brace on your finger. 2) Align the distal edge of the band with the cuticle. 3) Adjust the length of the band to fit your finger. 4) Insert the end of the band into the remaining hole to secure it in place. (5) Mode change (Figure 7): The brace can be changed from the flexible mode, which allows for slight movement, to the fixed mode, which is completely fixed, by rotating the brace 180 degrees and pushing it proximally. (6) Check the position and size when wearing the band in flexible mode (Figure 8). 1) Check that the edge of the distal band is aligned with the nail cuticle, 2) that the distal interphalangeal skin line passes through the center of the fenestration, and 3) that there is little space between the distal band and the nail. (7) Actual range of motion and play in flexible mode (Figure 9): There was approximately 10 degrees of play in flexion and extension of the DIP joint. Complete fixation can often be inconvenient in daily life, so approximately 10 degrees of play was considered an appropriate angle. (8) Check the position and size when wearing the band in fixed mode (Figure 10): 1) Check that the edge of the distal band and the articular surface of the DIP joint are aligned, 2) that the distal interphalangeal skin line passes through the middle between the bands, and 3) that there are no gaps between the distal band and the finger pad. (9) Actual range of motion and play in fixed mode (Figure 11): There was almost no play in flexion and extension of the DIP joint. This mode seems to be suitable for cases where complete fixation is required due to severe pain or for fixation of tendon-related mallet finger. (10) Weight: 1g, the same weight as a 1 yen coin. [Explanation of symbols]

[0011] 1 Distal Band 2 Proximal Band 3 Distal band fixing part 4 Proximal band fixing part 5 Distal finger pad band 6 Proximal finger pad band 7 Finger ventral fenestration 8 Distal band hole-1 9 Distal band hole-2 10 Distal band hole-3 11 Proximal band hole-1 12 Proximal band hole-2 13 Proximal band hole-3

Claims

1. This distal interphalangeal joint fixation orthosis is made of TPU, a flexible but non-stretching material that provides sufficient fixation even when thin, and is designed with flat cutting to form a cylindrical shape when rolled up.

2. 2. The distal interphalangeal joint fixation orthosis according to claim 1, wherein the position of the band is adjusted so that the edge of the distal band is aligned with the line of the nail cuticle and the proximal band fixes the central part of the middle phalanx, so that the orthosis can be worn even when the distal interphalangeal joint is severely swollen and deformed and there is tenderness.

3. The distal interphalangeal joint fixation orthosis according to claim 1 is designed so that the length of the band can be adjusted to fit the thickness of the finger by passing the band through the two holes at the opposite end, and the end of the band can be inserted into the third hole, whereby the end of the band is stored inside the orthosis and the band is fixed in place by friction.

4. The distal interphalangeal joint immobilization orthosis according to claim 1, wherein holes are made in the finger pads to reduce stuffiness, the finger pad portion is shifted proximally so that the band does not catch on the fingertip, and the band is designed with a gentle curve to reduce pain when bending force is applied to the distal interphalangeal joint.

5. In some daily activities, necessary movements cannot be performed unless the distal interphalangeal joint is in a state where there is some movement (a state where there is some play), and pain cannot be alleviated unless the distal interphalangeal joint is completely immobilized. However, the distal interphalangeal joint immobilization orthosis described in claim 1 can be changed from a flexible mode, in which there is some movement, to a fixed mode, in which the joint is completely immobilized, simply by rotating and pushing the orthosis in.

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