Patent Publication Number: US-2009240183-A1

Title: Support Device

Description:
The invention relates to an orthopaedic support device for supporting, protecting and immobilising part of a hand, and particularly, but not exclusively, to a 5 th  Metacarpal fracture splint. 
     The hand is made up of many bones, all of which are susceptible to fracture. There are five Metacarpal bones which make up the palm of the hand, each one connecting a finger or thumb to the bones in the wrist. The Metacarpal bones are numbered 1 to 5, the 1 st  Metacarpal being associated with the thumb, and the 5 th  Metacarpal being associated with the 4 th , or little finger. The 5 th  Metacarpal fracture is one of the most commonly seen hand fractures. It occurs at the neck of the bone close to the knuckle, often as a result of striking something or someone, and is therefore commonly referred to as ‘boxer fracture’. 
     There is currently no clear consensus within the medical profession as to the best way of setting these fractures; although it is widely agreed that some degree of immobilisation of the broken bone is beneficial. 
     In extreme cases, where there is a misalignment of the portions of the bone, surgery may be required to ensure that the fracture sets correctly. More commonly, the hand will simply be splinted to support the broken bone during the healing process. 
     Typically, a cast made of plaster of paris or fibreglass is formed around the hand, wrist and forearm of the patient. The hand is set in a fixed position, often with the fingers and palm in 90 degree flexion because this has been thought to be the preferred angle for healing. This is no longer universally accepted however. As an alternative to the cast, a forearm based splint may be applied under a compressive wrap. Casts have the advantage that the hand is well supported and protected during treatment, however the cast itself often proves inconvenient and uncomfortable for the wearer and may also, over the typical treatment duration of 4 to 6 weeks, cause allergies and joint stiffness. Swelling of the hand within the rigid cast can also lead to pressure and further discomfort for the wearer. In extreme cases, this can require visits to a hospital for evaluation. Furthermore, many medical professionals now believe that allowing movement of the hand during the course of treatment is beneficial, not only in reducing stiffness in the joints, but also in encouraging better bone healing, this movement is not possible with typical casts. 
     Another drawback of casting is that the process of forming the cast is time consuming and often calls for a specialist, which can result in long waiting times in A&amp;E departments. While a broken bone is not properly immobilised, there exists the possibility of further injury and damage to the surrounding muscles, blood vessels, tendons and nerves. It is therefore beneficial if the fracture is immobilised as quickly as possible. 
     A more simple approach is to merely tape the 4 th , or little finger, to the 3 rd , or ring finger thereby using one finger to splint the other. This provides a degree of support to the fractured Metacarpal while allowing continued functionality of the injured hand. Despite the simplicity of this approach, it has been shown to be effective. However, the fractured bone is provided no protection against accidental knocks which can be extremely painful. Furthermore, a common problem with Metacarpal fractures is that, during setting, the head of the bone (the knuckle) can become depressed resulting in a bump on the palm of the hand. This can cause discomfort when the hand is used, especially when gripping articles tightly. 
     U.S. Pat. No. 6,953,441 describes a preformed brace for treating 4 th  and 5 th  Metacarpal fractures which is attachable to the hand and wrist of the wearer by a number of straps. The brace consists of a semi rigid one-piece outer shell, which extends from above the wrist to the ends of the fingers along the outside of the hand and wrist of the wearer. The brace therefore only provides support to the outside of the wrist and hand, limiting the amount of support that can be provided. The brace places the wrist of the wearer in extension, with the fingers immobilised in flexion at an angle of 80 to 90 degrees. With the fingers immobilised at such a large angle there is substantial loss of functionality of the hand. 
     It is an object of the present invention to combine the benefits of the aforementioned methods while removing the associated drawbacks. In other words it is an object of the present invention to provide a comfortable lightweight and easily fitted support device that nonetheless provides improved support and protection for fractures. 
     According to the present invention there is provided an orthopaedic support device for supporting, protecting and immobilising part of a hand, the device comprising a preformed support member which, in use, extends along the wearer&#39;s wrist and hand, and is attachable thereto, so as to provide support with the hand disposed in one direction so that the wrist joint is at a given angle, and the fingers disposed in another direction so that the knuckles are at an angle substantially similar in magnitude but opposite in orientation to the wrist joint and not exceeding 55 degrees. 
     In general terms the invention has many advantages over the previously described support devices. It is shaped so as to provide not only support, but also impact protection to the broken bone while allowing the patient continued use of the hand for day to day activities such as writing. Beneficial flexing and extension of the hand and wrist can be achieved by the support, and by limiting the angles to considerably less than 90 degrees a far greater degree of functionality of the hand can be maintained. If the thumb, index finger and ring finger are left free by the device, the ‘tripod’ grip used in fine movements of the hand is possible. Preferably a substantial part of the width of the wrist and hand is supported by the device. In particular support should be provided for the 1 st  to 3 rd  Metacarpal as this is believed to be beneficial in reducing the deforming forces on the fracture site. This additional support also allows advantageous positioning of the wrist and hand in more than one plane. For example the support may be designed to place the hand at an angle in the lateral direction as well as the longitudinal direction. 
     Being preformed the support device can be fitted to a patient quickly and easily by a relatively unskilled person. This will minimise waiting times at A&amp;E departments and should also enable use of the device at the time and place of the injury, for example on the sports field. This is clearly beneficial since immobilising the fracture minimises the chances of any further damage to the hand and also reduces the pain and discomfort of the patient. 
     Means for cooling the skin may be provided. These are preferably ventilating means, preferably comprising apertures or perforations in the support member. 
     In a preferred embodiment, the support member is provided with releasable straps for fitting. The support is therefore easily removable for hand physiotherapy or cleaning (one of the main gripes of plaster of paris immobilisation). The patient is also able to remove and reapply the splint themselves during the course of treatment, either to allow the aforementioned beneficial movement of the hand, or simply to allow completely unrestricted use of the hand for short periods when greater dexterity is required. 
     The support device will advantageously be provided in a number of different sizes, and/or be provided with adjustable straps. This allows the device to be preformed but still be applicable to different sized patients. It is anticipated that the devices will range in size from 11 cm to 41 cm in length and from 5 cm to 10 cm in width. The provision of adjustable straps also permits some fine tuning of the fit of the device as may be required due to increased or decreased swelling of the injured hand. Such adjustment is not possible with a moulded cast, which would cause pressure, and lose its fit to the hand respectively. 
    
    
     
       Embodiments of the present invention will now be described in the following-detailed description, given by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a top view of a support device according to a first embodiment; 
         FIGS. 2 ,  3  and  4  are lateral cross-sectional views of the support device of  FIG. 1  taken at the lines marked in  FIG. 1  as II, III and IV respectively; 
         FIGS. 5 and 6  are longitudinal cross-sectional views of the support device of  FIG. 1 ; 
         FIG. 7  is a perspective view of the support device of  FIG. 1 , taken from the wrist end towards the fingers; 
         FIG. 8  is a top view of a preferred arrangement of straps for attaching the support device of  FIG. 1  to a patient; 
         FIG. 9  is a top view of a support device according to a second embodiment; 
         FIGS. 10 ,  11  and  12  are lateral cross-sectional views of the support device of  FIG. 9  taken at the lines marked in  FIG. 9  as X, XI and XII respectively; 
         FIG. 13  is a side view of the support device of  FIG. 9  taken from the thumb side towards the outside of the hand; 
         FIG. 14  is a perspective view of the support device of  FIG. 9 , viewed from the wrist end towards the fingers; and 
         FIGS. 15 and 16  are side and top views respectively of a preferred arrangement of straps for attaching the support device of  FIG. 9  to a patient. 
     
    
    
     Although all Figures show a device suitable for supporting the right hand and wrist of a patient, it will be understood that similar devices for the left hand are simply mirror images of those shown. 
     For convenience the dimensions and angles indicated by reference letters in the accompanying drawings are set out in the following tables. 
     FIGS. 1-8: 
       
     
       
         
           
               
               
               
            
               
                   
                   
               
               
                   
                 Dimensions (cm) 
                 Angles (°) 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 ID 
                 Minimum 
                 Maximum 
                 ID 
                 Angle 
                 Variance 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 A 
                 3 
                 7 
                 a 
                 25 
                 20 
               
               
                   
                 B 
                 5 
                 10 
                 b 
                 50 
                 20 
               
               
                   
                 C 
                 0.5 
                 4 
                 c 
                 60 
                 20 
               
               
                   
                 D 
                 4 
                 11 
                 d 
                 45 
                 20 
               
               
                   
                 E 
                 0.5 
                 2 
                 e 
                 90 
                 20 
               
               
                   
                 F 
                 2 
                 5 
                 f 
                 15 
                 20 
               
               
                   
                 G 
                 2 
                 6 
                 g 
                 45 
                 20 
               
            
           
           
               
               
               
               
               
            
               
                   
                 H 
                 3 
                 9 
                 (from the horizontal) 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 I 
                 1 
                 9 
                 h 
                 25 
                 20 
               
            
           
           
               
               
               
               
               
            
               
                   
                 J 
                 1 
                 3 
                 (from the horizontal) 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 K 
                 0.5 
                 3 
                 i 
                 40 
                 20 
               
               
                   
                 L 
                 5 
                 12 
                 j 
                 35 
                 20 
               
               
                   
                 M 
                 4 
                 8 
                 i 
                 40 
                 20 
               
               
                   
                 N 
                 2 
                 7 
                 j 
                 35 
                 20 
               
               
                   
                 Q 
                 1 
                 4 
               
               
                   
                 R 
                 5 
                 9 
               
               
                   
                   
               
            
           
         
       
     
     FIGS. 9-16: 
       
     
       
         
           
               
               
               
            
               
                   
                   
               
               
                   
                 Dimensions (cm) 
                 Angles (°) 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 ID 
                 Minimum 
                 Maximum 
                 ID 
                 Angle 
                 Variance 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 A′ 
                 6 
                 12 
                 a′ 
                 25 
                 20 
               
               
                   
                 B′ 
                 6 
                 13 
                 b′ 
                 20 
                 20 
               
               
                   
                 C′ 
                 2 
                 9 
                 c′ 
                 30 
                 20 
               
               
                   
                 D′ 
                 6 
                 16 
                 d′ 
                 35 
                 20 
               
               
                   
                 E′ 
                 12 
                 25 
                 e′ 
                 70 
                 20 
               
               
                   
                 F′ 
                 5 
                 7 
                 f′ 
                 10 
                 20 
               
               
                   
                 G′ 
                 7 
                 11 
                 g′ 
                 18 
                 20 
               
               
                   
                 H′ 
                 3 
                 5 
               
               
                   
                 I′ 
                 5 
                 10 
               
               
                   
                 J′ 
                 3 
                 6 
               
               
                   
                 K′ 
                 2 
                 6.5 
               
               
                   
                 L′ 
                 3 
                 8 
               
               
                   
                 M′ 
                 4 
                 10 
               
               
                   
                 N′ 
                 6 
                 15 
               
               
                   
                 P′ 
                 4 
                 11 
               
               
                   
                 Q′ 
                 6 
                 10 
               
               
                   
                 R′ 
                 1 
                 3 
               
               
                   
                 S′ 
                 4 
                 8 
               
               
                   
                 T′ 
                 6 
                 9 
               
               
                   
                 U′ 
                 6 
                 11 
               
               
                   
                   
               
            
           
         
       
     
     A first embodiment of the invention, as shown in  FIGS. 1-8 , is particularly appropriate for setting undisplaced fractures of the 5 th  Metacarpal bone. The support member ( 1 ) shown in  FIG. 1  is between 11 cm and 27 cm in overall length, and has a maximum width of between 5 cm and 10 cm to accommodate different sized patients. In use, it extends along the underside of the patient&#39;s arm from just above the wrist, down the hand and to the end of the 3 rd  and 4 th  fingers. As shown in  FIGS. 2 ,  3  and  4 , the support member ( 1 ) has an approximately ‘L’ shaped cross-section, the longer more horizontal part ( 2 ) providing the support under the patient&#39;s arm and hand with the shorter more vertical part ( 3 ) on the outside of the hand to provide protection for the fractured 5 th  Metacarpal bone. In this particular embodiment the support member ( 1 ) is shaped in a longitudinal direction so as to place the wrist in extension at an angle (a) between 25° and 65°, preferably at 45° and the fingers in flexion at a similar but opposite angle, as best shown in  FIG. 5 . The support also features a slope in the lateral direction, which places the hand at an angle so that the thumb is in an elevated position relative to the outside of the hand. This angle (d) is best shown in  FIGS. 3 and 7 , and is between 25° and 65°, preferably around 45°. A common problem with this type of injury is a lower position of the 4 th  knuckle after the Metacarpal fracture sets. Positioning the hand as described helps to maintain a high position of the 4 th  knuckle during the bone setting. 
     It is clear from the drawings that only the bottom portion of the hand and wrist is covered by the device. Swelling on the top of the hand is unimpeded by the support which is beneficial in preventing skin necrosis. The hand and wrist can also breathe more freely, this reduces the possibility of unwelcome allergic reactions. To further aid breathing ventilation means, for example apertures or perforations (not shown) may be provided in the support member. The device is also lightweight and is provided with straps ( 4 ) as shown in  FIG. 8 , so as to be easily removable and refittable if required. The use of adjustable and releasable straps ( 4 ) allows the wearer to loosen the device slightly if swelling of the hand is causing discomfort. As the swelling goes down in the course of treatment (typically days 5-7) the straps ( 4 ) can be tightened to take any slack and allow the device to provide the best possible support. This makes it far less of an inconvenience for the wearer than a traditional cast or splint. 
     A second embodiment of the present invention is shown in  FIGS. 9 to 16 , and is particularly suited to setting displaced fractures of the 5 th  Metacarpal bone. The support member ( 11 ) shown in  FIG. 9  is between 5 cm and 10 cm wide, and between 18 cm and 41 cm in length. As a result, it extends further along the patient&#39;s arm than the support member ( 1 ) of the first embodiment, the position of the wrist being approximately at the section line XI.  FIG. 9  also shows that the support provides angulation to the wrist and hand as viewed from above. The support member ( 11 ) takes the form of a spiral or a twisted ‘C’ shaped cross-section.  FIG. 13  shows this shape viewed from the side, while  FIG. 14  is a view from the wrist end looking towards the fingers. When applied, the support covers the top and sides of the forearm and most of the wrist, then twists through approximately 90 degrees to cover and protect the 4 th  and 5 th  Metacarpal bones on the outside of the hand and to support the 3 rd  and 4 th  fingers. This twisting is shown in the cross-sectional views of  FIGS. 10 ,  11  and  12 .  FIG. 13  shows that the support member ( 11 ) according to this particular embodiment is shaped in a longitudinal direction so as to place the wrist in flexion and the fingers in extension. Flexing the wrist reduces deforming forces on the flexor tendons, while extending the fingers serves to reduce the angle of deformity. The soft tissue of the hand in this arrangement will help to reduce the fracture leading to a better set of the bone. 
     The twisted ‘C’ shape cross-section of the second embodiment allows the support member ( 11 ) to surround the hand and wrist more completely than would otherwise be the case. As a result, the support of this embodiment advantageously offers a greater number of possible support positions for the hand and wrist. Although  FIGS. 9 to 16  show the support in a configuration to place the wrist in flexion and the fingers in extension, there is no reason why it could not be configured to place the wrist in extension with the fingers in flexion as in the previous embodiment. 
     Although more of the hand is covered than in the previous embodiment, a significant portion still remains uncovered, and is able to breathe freely. Ventilation means (not shown) may be provided as before. As before, the device is lightweight and is easily adjustable, removable and refittable, due to the provision of releasable and adjustable straps ( 14 ) as shown in  FIG. 16 . 
     While the above descriptions relate to embodiments concerned only with fractures of the 5 th  Metacarpal, it will be apparent to one skilled in the art that alternative embodiments exist within the scope of the claims that would also make the invention suitable for the treatment of other hand and wrist fractures, for example variations of the device could be made to support other fingers in a similar fashion. 
     The present invention is not limited to the specific embodiments described above. Alternative arrangements will be apparent to a reader skilled in the art.