Abstract:
Finger splints for use in connection with distal interphalangeal (DIP) joint fractures are disclosed. The splints include a ring element for positioning around a finger at a location proximal to the distal interphalangeal (DIP) joint and include an extension member that extends over the DIP joint and attaches to the fingernail.

Description:
The present application is a continuation of U.S. application Ser. No. 12/244,084, filed Oct. 2, 2008, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 60/997,318 filed on Oct. 2, 2007 and titled DIP RING EXTENSION SPLINT, which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     The present invention relates generally to a finger splint. More particularly, the present invention relates to a distal interphalangeal joint extension splint. 
     The present invention may be for use in treating finger injuries, e.g., “Mallet Finger.” “Mallet Finger” may occur when a force is directed at the distal finger resulting in an avulsion of the extensor tendon from the dorsum of the base of the distal phalanx. Currently, there are several splints on the market that are used to treat this injury. 
     Patient compliance is, however, an issue that may affect the outcome after treating these types of injuries, e.g., “Mallet Finger.” In many cases, the splint should be left in place for 6-8 weeks without removal. Many patients, however, remove these splints before the injury has completely healed for several reasons, e.g., not knowing that the splint should stay in place for 6-8 weeks, to wash their finger, etc. Early removal of the splint may result in failed healing and/or deformity. 
     SUMMARY OF THE INVENTION 
     The splint according to the present invention may include a ring element positioned around a finger at a location proximal to the distal interphalangeal (DIP) joint and include an extension member that attaches to the fingernail. The extension member extends over the DIP joint between the ring element and the fingernail. 
     The extension member is preferably positioned only over the top surface of the finger. Doing so may result in increased compliance because the patient retains use of the finger tip sensation and is preferably able to wash the finger without removing the splint. Further, in various embodiments, tape may not need to be used to hold the splint on the finger, which may reduce the possibility of allergic reaction to the adhesive where it contacts the patient&#39;s skin. 
     In one aspect, the present invention provides a finger splint for use in the treatment of finger injuries, the splint including a ring element sized to fit around a finger at a location proximal to the distal interphalangeal (DIP) joint; an extension member having a proximal end attached to the ring element and a distal end located distally from the ring element; and an attachment element attached to the extension member proximate the distal end of the extension member, wherein the attachment element is capable of attaching the extension member to a fingernail when the ring element is positioned around a finger. 
     In various embodiments, the splint may include one or more of the following features: the extension member may define an extension member axis between the proximal end and the distal end of the extension member, and the distance between the attachment element and the ring element along the extension member axis is adjustable; the extension member may include an aperture proximate the distal end of the extension member, and the position of the attachment element is adjustable within the aperture; the aperture of the extension member may include grooves on an interior surface of the aperture, and the attachment element may include a releasable locking mechanism, wherein the releasable locking mechanism cooperates with the grooves of the aperture of the extension member to lock the attachment element in a selected position within the aperture; the finger splint may position the finger or a finger in hyperextension; the attachment element may include adhesive for attachment to a fingernail on which the splint is mounted; the extension member may be adjustably attached to the ring element such that the distance between the distal end of the extension member and the ring element can be adjusted proximate the ring element; the ring element may be a closed member; the ring element may be in the form of a slot; the distal end of the extension member may have a concave surface shaped to receive a fingertip; the ring element may be in the form of a male portion and a female portion, wherein the male portion and the female portion screw together; the ring element may include a tab and ratchet mechanism. 
     In another aspect, the present invention may provide a method of restraining a finger, the method including locating a splint on a finger, wherein the splint includes a ring element positioned proximally from the distal interphalangeal joint and an attachment element positioned adjacent a fingernail of the finger, with an extension member connecting the attachment element to the ring element; and attaching the attachment element of the splint to the fingernail while the ring element is positioned on the finger. 
     In another aspect, the present invention provides a finger splint for use in the treatment of finger injuries, the splint including a ring element sized to fit over a middle phalanx of a finger, wherein the ring element defines a finger axis; an extension member extending along and aligned with the finger axis between a proximal end and a distal end, wherein the extension member is attached to the ring element at the proximal end of the extension member; and an attachment element attached to the extension member proximate the distal end of the extension member, wherein the attachment element is located between the extension member and a fingernail of the finger. The attachment element is optionally adjustably attached to the extension member such that the distance between the ring element and the attachment element is adjustable. 
     In another aspect, the present invention provides a finger splint for use in the treatment of finger injuries, the splint including a ring element; an extension member extending from the ring element between a proximal end and a distal end, wherein the extension member is attached to the ring element proximate the proximal end of the extension member; and an attachment element attached to the extension member at the distal end of the extension member, and wherein the distal end of the attachment element includes adhesive. The attachment element is optionally adjustably attached to the extension member such that the distance between the ring element and the attachment element is adjustable. 
     In another aspect, the present invention provides a finger splint for use in the treatment of finger injuries, the splint including a ring element sized to fit over a middle phalanx of a finger, wherein the ring element defines a finger axis; an extension member extending along and aligned with the finger axis between a proximal end and a distal end, wherein the extension member is attached to the ring element at the proximal end of the extension member; and an attachment element attached to the extension member proximate the distal end of the extension member, wherein the attachment element is located between the extension member and a fingernail of the finger when the splint is located on a finger, and wherein the attachment element includes a mechanical fastener system. The attachment element is optionally adjustably attached to the extension member such that the distance between the ring element and the attachment element is adjustable. 
     The finger splints of the present invention may include an extension member that defines an extension member axis, wherein a position of the attachment element is adjustable along the extension member axis. The extension member may include an aperture proximate the distal end of the extension member, and the position of the attachment element is adjustable within the aperture. The aperture of the extension member may include grooves on an interior surface of the aperture, and the attachment element may include a releasable locking mechanism, wherein the releasable locking mechanism cooperates with the grooves of the aperture of the extension member to lock the attachment element in a selected position within the aperture. 
     The finger splints of the present invention may include one or more of the following features: the finger splint may position the finger or a finger in hyperextension; the finger splint may position the finger or a finger in about 3 degrees of hyperextension; the adhesive (if provided) may be pressure sensitive adhesive; the extension member may be adjustably attached to the ring element such that the distance between the distal end of the extension member and the ring element can be adjusted proximate the ring element; the extension member and the ring element may be a one piece, completely integral molded polymer article; the ring element may be a closed member; the ring element may include a slot; the length of the ring element may be adjustable; the distal end of the extension member may include a concave surface shaped to receive a fingertip; the ring element may include a male portion and a female portion, wherein the male portion and the female portion screw together; etc. 
     In another aspect, the present invention may provide a method of restraining a finger by locating a splint according to the invention on a finger, wherein the ring element of the splint is positioned proximally from the distal interphalangeal joint and the attachment element is positioned adjacent a fingernail of the finger; and attaching the attachment element of the splint to the fingernail. The attachment element include adhesive and/or a mechanical fastener system. 
     These and other features and embodiments of the invention may be described below in connection with some exemplary embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWING 
         FIG. 1  depicts a perspective and illustrative view of one exemplary finger splint according to the current invention. 
         FIG. 2  is a side view of the splint of  FIG. 1  in place on a finger. 
         FIG. 3  is a partial side view another exemplary embodiment of a finger splint on a finger. 
         FIG. 4  is an enlarged cross-sectional view of a portion of the extension member depicted in FIG. 
         FIG. 5  is a side view of another exemplary splint according to the present invention. 
         FIG. 6  is a side view of the splint of  FIG. 5  in place on a finger. 
         FIG. 7  is an end view of another exemplary embodiment of a splint according to the present invention. 
         FIG. 8  is a side view of the splint of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     In the following detailed description of illustrative embodiments of the invention, reference is made to the accompanying figures of the drawing which form a part hereof, and in which are shown, by way of illustration, specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. 
     The words “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention. 
     As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably. The term “and/or” (if used) means one or all of the identified elements/features or a combination of any two or more of the identified elements/features. 
     The term “and/or” means one or all of the listed elements/features or a combination of any two or more of the listed elements/features. 
       FIG. 1  depicts a perspective and illustrative view of one exemplary finger splint according to the current invention. The finger splint  10  may include a ring element  12 , an extension member  13 , and an attachment element  16 . 
     The ring element  12  may be a solid, continuous cylinder as depicted, which is generally sized to fit over the middle phalanx of a finger. At least in one embodiment, the ring element  12  may be adjustable in length (along an axis defined by the finger), diameter, and/or circumference to accommodate different sizes and/or shapes of fingers. Further, at least in one embodiment, the ring element  12  may not be continuous, e.g., the ring element may include a slot or a notch such that the ring element extends less than 360 degrees around the finger. Still further, at least in one embodiment, the ring element  12  may not be circular, e.g., the ring element  12  may be elliptically or otherwise shaped to conform to the shape of a finger. Still further, in at least one embodiment, the ring element  12  may not be solid, e.g., the ring element  12  may be substantially hollow. 
     The extension member  13  in the depicted embodiment is a substantially straight member extending from a proximal end  14  to a distal end  15 . The proximal end  14  of the extension member  13  is attached to the ring element  12  and the extension member  13  extends to the distal end  15  substantially perpendicular to a plane  17  defined by the ring element  12  (which plane is also substantially perpendicular to a finger axis of a finger on which the ring element is positioned). In this embodiment, the extension member  13  is integral with the ring element  12 , i.e., the extension member  13  and the ring element  12  are provided as a one-piece, completely integral article that may be molded or otherwise formed (e.g., machined, sintered, etc.) from any suitable material (e.g., metal, polymer, ceramic, composites, etc.). 
     The ring element  12  and the extension member  13  may not be integral and may, instead, be separate pieces that may be fixedly and/or adjustably attached to each other. Although not shown, separate extension members and ring elements may be attached to each other through an adjustment mechanism so that the distance between the distal end  15  of the extension member  13  and the ring element  12  may be adjusted where, e.g., the extension member  13  attaches to the ring element  12 . 
     In some embodiments the extension member  13  may not extend from the ring element  12  in a substantially perpendicular direction relative to plane  17 , e.g., the extension member may extend from the plane at an angle that is not perpendicular to the plane  17 . In other variations, the extension member  13  may include, e.g., multiple bends or may be continuously curved instead of being substantially straight as depicted in  FIGS. 1 &amp; 2 . 
     In still other variations, the extension members of finger splints according to the present invention may be malleable such that the orientation of the extension member with respect to the ring element can be adjusted. The malleability may be provided by, e.g., constructing the extension member and/or ring element out of materials such as metals, plastics (potentially thermoplastics that can be heated to increase malleability), etc. Such malleability may also be useful for adjusting the shape of the extension member such that it avoids contact with the finger between the ring element and the fingernail. 
     The attachment element  16  as depicted in  FIG. 1  is located near the distal end  15  of the extension member  13  on the side of the extension member facing the interior of the ring element  12 . Generally, the attachment element  16  is used to fixedly attach the splint  10  to the fingernail of a finger on which the splint is mounted. The surface  18  of the attachment element  16  may preferably be adhered to the fingernail. In at least one embodiment, the attachment element  16  may include any suitable adhesive material, e.g., cyanoacrylate, epoxy, acrylic adhesives, etc. It may be preferred that the adhesive be a pressure sensitive adhesive. 
     In the depicted embodiment, the attachment element  16  is attached to the extension member  13  at a fixed, stationary location. The attachment element  16  may, however, be adjustably attached to the extension member  13 , i.e., the position of the attachment element  16  relative to the ring element  12  may be adjustable. For example, the extension member  13  and the attachment element  16  may be attached to each other using an adjustment mechanism so that the distance between the attachment element  16  and the ring element  12  may be adjusted. In another alternative, an adjustment mechanism may be located at the juncture between the ring element  12  and the extension member  13  (with the attachment element  16  in a fixed position on the extension member  13 ). In still another alternative, the adjustment mechanism may be in a form where the length of the extension member  13  is adjustable, e.g., the extension member  13  may have a telescoping structure, etc. 
     Although depicted as a separate body in  FIGS. 1 &amp; 2 , the attachment element  16  may be integral with the extension member  13 . In perhaps its simplest form, the attachment element  16  may be provided as a mass of adhesive that may or may not have a visually discernable thickness (for example, the attachment element may be in the form a thin layer of cyanoacrylate adhesive located between the extension member  13  and the fingernail  22 ). In other embodiments, the attachment element  16  may have a thickness and a volume as depicted in  FIGS. 1 &amp; 2 . In such embodiments, the attachment element  16  may be rigid or resilient. For example, the attachment element  16  may include a resilient body that carries the adhesive used to attach the splint to a fingernail or the body of the attachment element  16  may consist essentially of adhesive. If provided as a resilient body, the resilience of the attachment element  16  may provide some compliance between the extension member  13  and the fingernail  22  to which the device is attached. 
     In still other embodiments, the attachment element may include a mechanical fastener system that includes two components that attach to each other. Examples of some potentially suitable mechanical fastener systems may include hook and loop closures (examples of which are available under the tradename VELCRO), mating fastener elements, etc. (see, e.g., U.S. Pat. Nos. 5,077,870; 6,076,238; etc.). If a mechanical fastener system is used, it may be preferred that one component be attached (e.g., adhesively) to the fingernail and the mating component be attached to the extension member. Attachment of the two components to each other then serves to attach the fingernail to the extension member. 
       FIG. 2  depicts a perspective and illustrative view of exemplary splint  10  in position on a finger  20 . The bones of the finger  20  are depicted to better illustrate the functionality of the splint  10 . More specifically, the finger  20  includes skin  21 , a fingernail  22 , a distal phalanx  24 , a middle phalanx  26 , and a distal interphalangeal joint  28 . As shown in this depiction, the ring element  12  of the splint  10  is located around the middle phalanx  26  of the finger  20  at a location proximal to the distal interphalangeal joint  28 . The extension member  13  extends from the ring element  12  to the tip of the distal phalanx  24 . 
     The attachment element  16 , as shown, is attached to the fingernail  22 . The attachment element  16  may be used to retain the splint  10  on the finger  20 . In turn, the splint  10  may prohibit substantial movement of the distal phalanx  24  at the distal interphalangeal joint  28  as to, e.g., allow an extensor tendon to heal. The adhesive of the attachment element  16  preferably remains selectively attached to the fingernail  22 . For example, the adhesive may remain attached for a fixed time period based on average deterioration of the adhesive. Further, for example, the adhesive may remain attached until a releasing compound (e.g., a solvent) is used on the adhesive. Still further, for example, the adhesive may be selected such that it remains attached to the fingernail  22  under a selected amount of force. The selected force may, for example, be greater than the force that a finger may apply to the distal phalanx  24  of that finger. 
     In at least one embodiment, the splint  10  may secure the distal phalanx  24  in a position that supplies hyperextension, i.e., movement beyond the normal range of motion of the distal phalanx  24  in the dorsal direction. It may be preferred that the splint  10  be capable of securing the distal phalanx  24  in about 3 degrees or more of hyperextension. In another characterization, the splint  10  may secure the distal phalanx  24  in some amount of hyperextension up to about, e.g., 5, 10, or even 15 degrees of hyperextension. 
       FIG. 3  is a partial side view another exemplary embodiment of a finger splint  110  on a finger  120  according to the current invention.  FIG. 4  is an enlarged view of the attachment element  116  and a portion of the extension member  113  of  FIG. 3 . Only the distal portion of the finger  120  and distal portion of the finger splint  110  are shown in  FIGS. 3 &amp; 4 . 
     In the embodiment depicted in  FIGS. 3 &amp; 4 , the attachment element  116  is movable along the length of the extension member  113 . This feature may be useful because, as the fingernail  122  grows and the attachment element  116  remains attached to the fingernail  122 , the splint  110  will move distally with the growth of the fingernail  122 . In turn, this movement may reposition the splint  110 , which may hamper the functionality of the splint  110 , e.g., the ring element portion of the splint  110  may be moved from the middle phalanx to or past the distal interphalangeal joint, which may reduce the effectiveness of the splint  110  at immobilizing the distal interphalangeal joint. 
     One embodiment of a finger splint that may address the problem of fingernail growth is depicted in  FIGS. 3 &amp; 4 . The attachment element  116  may be movable relative to the extension member  113 . As the fingernail  122  grows and moves the splint  110  out of its proper position, the attachment element  116  may be unlocked, repositioned, and re-locked as to properly function, e.g., to substantially immobilize the distal interphalangeal joint. These adjustments are preferably performed without removing the splint  110 . 
     In the depicted mechanism, an adhesive plate  130  is attached to the fingernail  122  of the finger  120 . The adhesive plate  130  may be formed of a resilient or rigid material. The surface  118  of the adhesive plate  130  is the portion of the adhesive plate  130  that contacts the fingernail  122  and may be adhered to the fingernail  122 . The surface  118  may be adhesive itself or an adhesive substance may be applied to the surface  118  before attachment to the fingernail  122 . 
     The side of the adhesive plate  130  opposite the surface  118  is attached to a slide  132 . The slide  132  is located within a slot formed in the extension member  113 . The slot may preferably extend through the extension member from the anterior side (i.e., the finger side) to the posterior side. An upper portion of the slide  132  includes a rail  134  that protrudes from the sides of the slide  132 . The rail  134  cooperates with structure  152  in the slot to retain the attachment element  116  within the slot. Generally, the slot is sized to precisely fit the slide element  132  within so as to allow limited (if any) lateral movement (i.e., movement that is not along the longitudinal axis defined by the extension member  113 ). 
     A tubular element  137  is attached to the top of the slide  132  and extends towards to the posterior side of the extension member  113 . The tubular element  137  may have a circular cross section, square cross section, or any other cross-sectional shape. 
     The adhesive plate  130 , the slide  132 , the rail  134 , and the tubular element  137  may be integral with each other (e.g., molded as a one-piece, completely integral unit). Alternatively, the adhesive plate  130 , the slide  132 , the rail  134 , and the tubular element  137  may be provided in two or more separate parts that are attached to one another. The adhesive plate  130 , the slide  132 , the rail  134 , and the tubular element  137  may be formed of the same material, or different materials. Generally, these elements may be formed of rigid materials. 
     A resilient member  136  may be provided within the tubular element  137 . Although in this embodiment, the resilient member  136  is depicted as a coil spring, the resilient member  136  may be formed of any resilient material in any shape as would be known by one having skill in the art. For example, the resilient member may be formed of foam, silicone elastomer, rubber, etc. 
     The top of the resilient member  136  is adjacent to the plunger portion  138  of the button  142 . The button  142  has a plunger portion  138 , a grooved portion  140 , and a top  144 . The plunger portion  138 , the grooved portion  140 , and the top  144  may be of one-piece, completely integral construction or may be separate parts that are fixedly attached. 
     The grooved portion  140  of the button  142  may be sized to fit within the grooves  158  of the slot of the extension member  113  so as to immobilize the attachment element  116  with the extension member  113 . When the resilient member  136  is in an uncompressed state, the grooved portion  140  of the button  142  preferably mates with the grooves  158  of the slot of the extension member  113  to prevent movement of the attachment element  116  relative to the extension member  113 . Movement of the attachment element  116  may be accomplished by depressing the top  144  of the button  142  to compress the resilient member  136  and move the grooved portion  140  of the button  142  out of the grooves  158  of the slot. Depressing the top  144  of the button  142  in this manner will unlock the attachment element  116  from the extension member  113 , which allows the location of the attachment element  116  along the extension member  113  to be adjusted to, e.g., compensate for fingernail growth. 
     Another exemplary embodiment of a finger splint  210  that may address the problem of fingernail growth is depicted in  FIGS. 5 &amp; 6 . The ring element  212  is extendable along its longitudinal axis so that when the fingernail  222  of finger  220  grows and moves the splint  210 , the distance between the attachment element  216  and the ring element  212  may be adjusted. 
     The extension member  213  extends from the ring element  212  to the tip of the finger  220  as to support the joint between the distal interphalangeal joint. This embodiment includes an optional concave portion  219  of the extension member  213  formed near the distal end  217  of the extension member  213  and sized to receive the tip of finger  220 . The concave portion  219  may have many uses such as to partially secure the finger  220  within the splint  210  and/or to protect the finger  220  from “jamming.” In this embodiment, the extension member  213  extends from the ring element  212  substantially perpendicular to a plane formed through the ring element  212 . 
     Near the midsection of the extension member  213 , i.e., between the concave portion  217  and the ring element  212 , the extension member  213  tapers as to form an angle  275 . The angle  275  may be, e.g., greater than zero degrees to about 25 degrees. The extension member  213  may preferably position the distal interphalangeal joint of the finger  220  in hyperextension as shown in  FIG. 6 . 
     In the adjustment mechanism associated with this embodiment, the ring element  212  has two sections: a threaded male section  260  and a threaded female section  262 . The male section  260  mates the female section  262  and the inner male section  260  may preferably be positioned proximal to the distal interphalangeal joint to properly position the splint  210 . In  FIG. 5 , the male section  260  is partially unscrewed from the female section  262  as to extend the ring element  212  and increase the distance between the inner male section  260  and the attachment element  216 . In  FIG. 6 , the male section  260  is fully screwed into the female section  262 . Dotted line  264  signifies where the screw portion of the male section  260  resides within the female section  262 . 
     The ring element  212  may include indicia on the male section  260  and the female section  262  that correspond with each other as to show a user the distance the male section  260  has been screwed into the female section  262 . 
     Another exemplary embodiment of a finger splint according to the present invention is depicted in  FIGS. 7 and 8 , with  FIG. 7  being a view taken along the axis of the extension member  313  of the finger splint  310  and  FIG. 8  being a side view of the finger splint  310 . The finger splint  310  includes a ring element  312  that includes a tab  370  that fits within a slot  372  to form a closed loop so that the ring element  312  can be retained in place on a finger. The tab  370  may preferably include a ratchet mechanism that includes slotted surface  374  that cooperates with a pawl (not shown) located in the slot  372  to prevent removal of the tab  370  from the slot  372 . 
     In essence, the tab  370  and slot  372  function in the manner of a cable tie. In some embodiments, the ratchet mechanism may include structure that allows for release of the pawl (if, e.g., the tab  370  is pulled too far through the slot  372 ). As seen in  FIG. 8 , the portion of the tab  370  may be removed after the ring element  312  is in a select position. Although the tab  370  is depicted as an integral component with the ring element  312 , the ring element  312  may be provided separately from the tab  370  such that the tab  370  is provided in the form of a discrete article (e.g., a cable tie) that cooperates with the ring element  312  (e.g., is fitted in a slot, channel, through guides, etc.). 
     Although the exemplary embodiments described herein depict the finger splint utilized with a finger, the finger splint may be used on other appendages, such as, but not limited to, toes on a foot. Further, although the exemplary embodiments described herein depict the finger splint utilized with the distal interphalangeal joint, the finger splint may be used on other joints, such as, but not limited to, the proximal interphalangeal joint. 
     The complete disclosure of the patents, patent documents, and publications cited in the Background, the Summary, the Detailed Description of Exemplary Embodiments, and elsewhere herein are incorporated by reference in their entirety as if each were individually incorporated. Exemplary embodiments of the present invention are described above. Those skilled in the art will recognize that many embodiments are possible within the scope of the invention. Other variations, modifications, and combinations of the various components and methods described herein can certainly be made and still fall within the scope of the invention. Thus, the invention is limited only by the following claims and equivalents thereto.