Abstract
A method to produce a brace for fixing a position of a broken bone in a first limb, includes the steps of making an image of a residual limb that corresponds to the first limb, and producing the brace by making a three-dimensional appliance that has dimensions that correspond to the image of the residual limb and which is constituted to adjustably enclose the broken limb.
Claims
1. A method to produce a brace for fixing a position of a broken bone in a first limb, comprising the steps of: making an image of a residual limb that corresponds to the first limb, and producing the brace by making a three-dimensional appliance that has dimensions that correspond to the image of the residual limb and which is constructed to adjustably enclose the broken limb.
2. A method according to claim 1, wherein the step of producing includes the step of creating the appliance from two separate support elements that have an adjustable mutual spatial configuration to provide for the adjustable enclosure of the limb.
3. A method according to claim 2, wherein the step of producing includes the step of configuring the two separate support elements to support the broken limb at opposing sides thereof.
4. A method according to claim 2, wherein the step of producing includes the step of forming one of the support elements to have two separate supporting surfaces to be contiguous with a surface of the first limb.
5. A method according to claim 1, wherein the step of making includes the step of making the image as a three dimensional image.
6. A method according to claim 1, further comprising the step of, before the image is made, bringing the residual limb in a predetermined position, after which the image is made while the residual limb takes said predetermined position.
7. A method according to claim 6, further comprising the step of bringing the first limb in a position that corresponds to said predetermined position, before the brace is placed to support the first limb.
8. A method according to claim 6, wherein the step of bringing includes the step of obtaining the predetermined position by applying a traction force to the corresponding limb.
9. A method according to claim 1, wherein the first limb arm has a distal radius fracture.
10. A method according to claim 1, wherein the step of making includes the step of making the image as a three-dimensional image by one of the following: a stereoscopic scanner, a laser scanner and a photogrammetric scanner.
11. A method according to claim 1, wherein the step of producing includes the step of producing the brace using a 3D printer.
12. A method to produce a brace for fixing a position of a broken bone in a first limb, comprising the steps of: making a three-dimensional image of a residual limb that corresponds to the first limb, and producing the brace by making a three-dimensional appliance having dimensions that correspond to a mirror image of said three-dimensional image.
13. A brace produced with a method according to claim 1.
14. A brace for fixing a position of a broken bone in a first limb, the brace having a shape that corresponds to a shape of a residual limb that corresponds to the first limb, the brace comprising two separate support elements that have an adjustable mutual spatial configuration to provide for a construction to adjustably enclose the broken limb.
15. A method for fixing a position of a broken bone in a first limb, comprising the steps of providing a brace according to claim 13, and placing the brace around the first limb independent of an amount of swelling of the limb.
16. A method according to claim 15, wherein the step of placing including the step of placing the brace within 24 hours after the bone in the limb was broken.
17. A method for fixing a position of a broken bone in a first limb, comprising the steps of providing a brace according to claim 14, and placing the brace around the first limb independent of an amount of swelling of the limb.
18. A method according to claim 15, wherein the step of placing including the step of placing the brace within 24 hours after the bone in the limb was broken.
Description
EXAMPLES
[0029] FIG. 1 provides a schematic view of a patient having a broken arm undergoing a method according to the present invention.
[0030] FIG. 2 provides a schematic representation for a system to perform the method according to the invention.
[0031] FIG. 3 provides a schematic representation of a brace produced according to the invention.
[0032] FIG. 4 provides a schematic representation of another brace produced according to the invention.
[0033] FIG. 5 provides a front view of the brace of FIG. 4.
[0034] FIG. 6 shows the basic parts of the brace of FIG. 4.
[0035] Example 1 assessment of symmetrical shape of corresponding limbs
[0036] Example 2 describes a test with live subject having healthy limbs to assess the fitting of a brace according to the invention.
[0037] Example 3 describes a human cadaver study with a brace according to FIG. 4.
[0038] FIG. 1
[0039] FIG. 1 provides a schematic view of a patient 1 having a broken arm 2, in this case a distal radius fracture needing (closed) reduction and fixation by an external brace for proper healing. Firstly, the patient 1 puts his residual (unbroken) arm 3 in a stereoscopic scanner 5. The opening 4 of this scanner, in combination with the finger trap traction device 6 make sure that the forearm is brought in a predetermined position. Alternatively, the arm is broken in a scanner while resting on a standard support to make sure the arm obtains a predetermined positon (for such an alternative process a standard scanner such as the laseroptic Footin3D scanner available from Elinvision, Biruliskiu village, Lithuania) can be advantageously used.
[0040] The process is monitored using central computer 15 (having a wireless connection 7 with the scanner) which is operator controlled. As soon as the computer establishes, by analysing pre scans of scanner 5, that the forearm is in the proper position, the patient is told by the operator to keep still and a three dimensional scan of the forearm of arm 3 is made. The resulting three-dimensional image of the forearm is processed in the computer 15 and mirror imaged. This way the three dimensional image of the residual arm 3 is turned into an (imaginary) three dimensional image of the broken arm 2. In a next step, a computer model of a brace is (automatically) designed. This brace has dimensions that correspond to the image of the residual limb since its dimensions fit the dimensions of the mirror image of the residual arm. This design of the brace is sent to a 3D printer (see FIG. 2), such as for example a Fortus 250mc as available from Stratasys, Eden Prairie, Minn., United States. This printer is able to rapidly print any appliance from a material having the required rigidity and elasticity for a brace after hardening. By using the mirror image of the residual limb as a model for the appliance, it is provided that the newly designed three-dimensional appliance has (inner) dimensions that exactly correspond to a mirror image of the said three-dimensional image, i.e. this appliance neatly fits an imaginary arm having the spatial configuration of this mirror image. Since the normal 3D form of the broken arm correspond to the mirror image of the residual arm (see Example 1 here below), the printed appliance inherently is a brace that corresponds to the arm 2 after proper reduction. The whole process of scanning and printing, depending mainly on the required size of the brace and the type of ink, may take between 10 and 60 minutes using a common 3D printing apparatus such as the ones used for rapid prototyping.
[0041] After the brace (see FIGS. 3 and 4) has been produced, the computer provides instructions to guide the patient and medic to bring the broken arm 2 in a position that corresponds to the position the arm 3 took in the scanner 5. For this, the patient puts his arm through opening 40 of wall 50, where after a finger trap traction device 60 is applied. The opening 40, wall 50 and finger trap traction device 60 correspond to the opening 4 of scanner 5 and finger trap traction device 6. This way the reduced arm 2 can be brought in a position that corresponds to the position arm 3 had while being scanned. Alternatively, the broken bone is slightly over corrected to ensure that it sets into the exact right position after the brace has been placed around the arm. Another possibility is to design a brace that has such an over correction incorporated, or to apply both types of overcorrection. In any case, in a final step the brace is placed around arm 2 to support this arm and fix the position of the broken bone.
[0042] FIG. 2
[0043] FIG. 2 provides a schematic representation for a system to perform the method according to the invention. In this view, scanner 5 is depicted while being in operative connection via wireless line 7 with computer 15. This computer 15 on its turn is in operative connection via a wireless line 70 with 3D printer 16.
[0044] FIG. 3
[0045] FIG. 3 provides a schematic representation of a brace produced according to the invention. In this case the brace 20 is a longitudinal brace of the type used for supporting a forearm. The brace is made from an ink that after curing (hardening) is elastic, but which has an elastic modulus of a value such that the brace is capable to provide sufficient overall rigidity to provide for spatial fixation of the reduced bone. The brace is provided with a cleavage 23 over its entire length. In this case the cleavage runs almost parallel to the longitudinal axis of the brace. In order to be able and close the brace, closure means 24, 24 and 24 are provided which means are formed integrally with the brace by the 3D printer. The closure means are adjustable such that the brace when being closed can leave an opening at the site of the cleavage or can be completely closed. This way the brace can adjustably enclose the broken limb. By having the brace made as a constitution with an adjustable enclosure, the amount of swelling can be taken into account when fitting the brace around the broken limb and still have an adequate enclosure. Right after the bone is broken, the amount of swelling is typically high and the brace may be positioned with the cleavage wide open. With the swelling going away, the cleavage may be gradually closed to arrive at a corresponding continuous enclosure of the limb.
[0046] The material of the brace has no sharp edges, is provided in a fish-net like structure of rigid ribbons 21, leaving openings 22. This makes the brace very light when compared to common plaster casts. Also, the cured material (which is typically a polymer) can be chosen to be water resistant, such that bathing with the brace is an option. The openings 22 make sure the arm can dry after bathing. It is also foreseen that the brace is provided with a separate element, such as a metal or carbon fibre reinforced rod, to provide for additional rigidity if needed. This provides for more freedom in choice of printing ink (or, in case 3D printing is not the method of choice, more freedom in choosing this method and the material used). Such an element can be incorporated in the 3D print or attached after printing.
[0047] In an alternative embodiment closure means are used that are separate from the brace itself such as for example ty-wrap like ribbons. This provides that the brace is easier (and faster) to produce. Also, the closure means can be chosen such that they cannot be opened by the patient himself.
[0048] FIG. 4
[0049] FIG. 4 provides a schematic representation of another brace produced according to the invention, which is a brace that is easier to adjustably enclose different cross sectional shapes of the broken arm 2 when compared with the brace of FIG. 3. The brace 20 in this case comprises two separate support elements that have an adjustable mutual spatial configuration to provide for the adjustable enclosure of the arm. The first of these support elements, element 200 comprises two separate supporting surfaces 201 and 202 which are positioned on top of the broken arm 2 to be contiguous with its upper surface. Each of these supporting surfaces has a structure of rigid ribbons 21 that surround holes 22 (cf. structure of brace of FIG. 3). These supporting surfaces are interconnected via rods 220 and 221 that are slidably connected into clamping ribs 211 and 214 respectively. On the opposing underside the second support element 203 is present (not denoted in FIG. 4; see FIGS. 5 and 6). Of this support element 203 only the clamping ribs 212 and 215 can be seen in the bird's eye view of FIG. 4. Both elements (the element that is comprised of support surfaces 201 and 202, and the element 203) together are configured to support the broken arm at opposing sides thereof.
[0050] The brace 20 is a three-dimensional appliance that has dimensions that correspond to the image of the residual arm (not shown in FIG. 4) and the constitution is such that the arm is adjustably enclosed. For this, opposing clamping ribs can be moved towards and away from each other, decreasing or increasing open space 213 and 216 respectively. For this use is made of screw means 217 (not shown in FIG. 4; see FIG. 5). By increasing or decreasing the space using screw means 217 the enclosure of the arm is controlled. The external forces applied to the screw means can be used to reach a predetermined three-dimensional shape for the brace, so that the arm is nicely enclosed independent of the level of swelling of the arm. Local (typically very small) swelling can be taken into account by using a padding on the supporting surfaces.
[0051] FIG. 5
[0052] FIG. 5 provides a front end view of the brace of FIG. 4. In this front end view, lower support element 203 can be seen with its clamping rib 215 attached to the support surface. The upper element 200 with its support surfaces 201 and 203 is also depicted, including clamping rib 214 that opposes clamping rib 215. As can be seen in FIG. 5, screw means 217 (217, 217) are present to adjust the space 216 between the two clamping elements (indicated with arrows A and B). This way the cross-sectional dimension of the brace can be adjusted to makes sure the arm is enclosed independent of the level of swelling.
[0053] FIG. 6
[0054] FIG. 6 shows the basic parts of the brace of FIG. 4 while of being assembled to form the brace 20. Depicted are support element 203 with its clamping ribs 212 and 215, as well as the supporting surfaces 201 and 202 that together form the second support element 200 using rods 220 and 221 to connect the two support surfaces.
Example 1
[0055] This example describes an assessment of symmetrical shape of corresponding limbs. For this assessment the dimensions of the lower arm of 56 healthy adults who did not previously had a fracture in their lower arm was measured by one medically trained practitioner. Of the subjects the following measures were taken: 1) the circumferential length of the hand at the first webspace, 2) the smallest circumferential length around the wrist adjacent (distally) of the ulnar styloid, 3) the smallest circumferential length of the lower arm, proximal of the wrist, 4) the circumferential length of the lower arm at the elbow crease and 5) the distance between the lateral epicondyle to the styloid radius process. The results indicated that although measures 1) through 4) are on average slightly higher for rights arms then for left arms, the overall resemblance of the measures is very high. This shows that an image of one arm can be sued to create a brace for the other arm.
Example 2
[0056] Example 2 describes a test with live human subjects having healthy limbs to assess the fitting of a brace according to the invention. For this test a first subject, healthy male, 54 years of age, was used. Of this subject one arm was scanned to deliver a three-dimensional image of that arm. Based on that image, a brace was made according to FIG. 4. This brace was provided with Delta-Dry softliner (available from BSN Medical Inc., Charlotte, N.C., USA) and worn by the subject for 4 days. Apart from some very light red spots, no clinical signs could be observed. The brace was comfortable to wear and after showering dried very quickly.
[0057] As a comparison, a second subject, a healthy female, 56 years of age and a third subject, a healthy male of 31 years of age, wore corresponding braces (see FIG. 4), but not modelled using an image of one of their own arms, but using a normalised model of an arm. It appeared that the brace was not able to provide optimal support against rotation of the arm and also, even after a mere 24 hours induced local clinical signs on the lower arm (red skin and indentations) in particular radial dorsal and ulnar volar.
Example 3
[0058] Example 3 describes a human cadaver study with a brace according to FIG. 4. For the study multiple cadaver arms of two types are used, fresh frozen and models created using Anubifix balsam (Erasmus University, Rotterdam, The Netherlands). Each arm is imaged to create a corresponding brace. Before the bone in each of the arms is broken, each arm is tested for its mobility in the wrists by performing a standardised test on the arm. The results are recorded by pictures in a situation of maximum flexing and maximum extension of the wrist. Thereafter standardised X-ray images are taken of the wrist in two directions. This way each arm is imaged with the bone intact. Then a Colles' fracture is made with osteotomic surgery via dorsal entry of the arm (as described by Baumbach et al. in BMC Musculoskeletal disorders, 2012, 12-252; Assessment of a novel biomechanical fracture model for distal radius fractures). The arm is closed after the surgery. Then the arm is subjected to the same test as described before and the same pictures and X-ray images are made. This should show the Colles' fracture. If so, the brace is mounted (if needed after reduction of the broken bone), while the arm is under manually applied tensile stress, to enclose the arm. Thereafter, the arm is again subjected to the same test, and pictures and X-rays are being made. If needed, the enclosure the brace is adjusted to fit the arm and the test is repeated. If the broken bone keeps its position, the arm is brought in maximum flexion and maximum extension for twenty times in a row and the test is again repeated to check the fixation of the bone The results indicate that an adequate fixation of the position of a broken bone in an arm can be obtained.
[0059] The brace according to the current invention in its broadest sense, can be constituted as a relatively open structure which has several advantages. The first type of advantages are practical ones, less enclosure inherently means a lighter brace, easier to wear and less risk of irritation and rashes. Secondly, a relatively open structure provides the possibility to inspect the enclosed limb with the naked human eye, or to make images of the enclosed limb itself, without needing to remove the brace or to use X-ray. In an embodiment a patient could make various images of the enclosed limb, the images for example being taken from multiple angles with a smart-phone, which images can be send to the medical practitioner and after image analysis provide a good basis for deciding whether or not the bones are properly fixed. This could be used to prevent that X-ray images have to be made in each and all cases. To make visual inspection even easier, it is proposed to manufacture the brace of a translucent material. Translucent plastic, as well as translucent materials suitable to act as padding, as such are known in the art and could, when combined, advantageously be used to produce a brace according to the invention, the brace allowing visual inspection through the brace itself.
