US20050274046A1 - Fracture walker with horseshoe heel pad beneath insole - Google Patents

Abstract

A method and apparatus for locating a calcaneus within a fracture walker is disclosed. The apparatus includes a locating device that has a notch formed therein, and an insole covering the locating device whereby the ankle forms a depression in the insole adjacent the notch when force is applied through the ankle on the insole.

Description

FIELD OF THE INVENTION
• The present invention generally relates to a fracture walker, and more particularly to a method and apparatus for locating the foot within a fracture walker.
BACKGROUND OF THE INVENTION
• Fracture walkers are often used to stabilize the ankle and lower extremity to encourage healing after a surgery or injury. A typical fracture walker can be used to limit the ankle flexion to either a fixed position or to a chosen range of dorsiflexion and/or plantarflexion. A typical fracture walker includes a foot platform portion and a lower leg portion. Generally, adjustable hinges are located between these two portions in order to allow some degree of ankle movement or to lock the ankle from movement. A typical fracture walker is sized such that it can be used for either the right or left leg thereby requiring the foot portion to accommodate either a right or left foot. Accordingly, the foot portion is generally rectangular to accommodate the various shapes of feet. Generally, straps are provided to secure the lower extremity within a fracture walker. These straps are located across the forefoot and around the lower leg in order to tighten the foot portion and the lower leg portion. Typically, the rear of the foot portion is sized to accommodate a variety of ankles while providing for ankle movement and flexion.
• When walking, the biomechanics of human gait involves the calcaneus, or heel bone, inverting and everting as the tibia rotates and counter rotates. This movement of the calcaneus occurs after heel strike and during the midstance and terminal stance phases of the walking cycle. Ideally, the non-parallel alignment of the midtarsal axes permits the foot to become rigid to support the body's weight and to provide a rigid lever for propulsion.
• During heel strike with a fracture walker, the forefoot and lower limb above the ankle are secured within the fracture walker. A misalignment of step or nonlevel walking surface may result in a shifting or twisting of the foot platform as weight is applied through the lower limb (loading response phase of the walking cycle). This shifting or twisting can cause a loss of balance to the patient to the extent that additional weight is shifted to the lower limb as the upper body is rotated to regain balance. This twisting of the foot platform relative the upper body can cause an unrestrained calcaneus to relocate within the fracture walker. With the forefoot essentially immobile relative to the fracture walker, movement of the calcaneus relative to the fracture walker can occur to alter the ideal alignment of the midtarsal axes. During further movement (midstance), the calcaneus will not be properly positioned for supporting body weight. This misalignment can cause new injuries, prolong healing or complicate existing injuries.
• A typical method for properly locating the calcaneus in a fracture walker involves wrapping pads around the vertical surfaces of the heel in order to position the calcaneus within the foot portion. These pads are wrapped around the heel and are required to fit tightly to prevent undesirable movement. Tightly restraining the ankle is undesirable for patients with an ankle injury and is a special concern for patients with edema in the lower extremity or diabetes. Additionally, the heel is ideally allowed to move within a fracture walker when the patient's weight is not being applied thereto. What is needed is an improved positioning system for a fracture walker to locate the calcaneus during weight bearing and heel strike.
SUMMARY OF THE INVENTION
• In accordance with the teaching of the present invention, a method and apparatus for locating a calcaneus within a fracture walker is disclosed. In one form, the present invention provides a fracture walker having a foot platform with a base and an insole covering the base. A locating device is interposed between the foot platform and the insole. The locating device includes a fore portion having a notch therein extending to a forward surface. The locating device is adapted to locate a calcaneus within the fracture walker. In another form, the present invention provides a method of locating a calcaneus within a fracture walker wherein a locating device adapted to correctly locate the calcaneus laterally within a medial-lateral heel space adjacent the calcaneus within the fracture walker is provided.
• Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
• The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
• FIG. 1 illustrates a perspective view of a fracture walker in accordance with the present invention;
• FIG. 2 is a cutaway view of a left ankle located within the fracture walker ofFIG. 1;
• FIG. 3 is an exploded partial perspective view of the fracture walker ofFIG. 1;
• FIG. 4 is a perspective view of a locating device shown within a partial section of the fracture walker ofFIG. 1;
• FIG. 5 is an alternate embodiment of the locating device ofFIG. 4; and
• FIG. 6 is a further alternate embodiment of the locating device ofFIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• The following description of the preferred embodiment of a method and apparatus for locating a calcaneus within a fracture walker is merely exemplary in nature and is in no way intended to limit the invention, its applications or uses. It should be appreciated that the locating device, while shown as a horseshoe shaped member, may be any shape that allows the calcaneus to be properly positioned within a fracture walker.
• FIG. 1 illustrates a fracture walker in accordance with the present invention referred to generally asnumeral10.Fracture walker10 includes afoot platform12, a pair ofhinge assemblies14, aleg assembly16, aliner18, straps20, aninsole22, and a locatingdevice24.Foot platform12 includes abase26 with arear lip28 around the back of a foot andframe members30 extending therefrom around the medial and lateral sides of a foot.Frame members30 havestrap attachment apertures32 and hingeattachment locations34 formed therein.Leg assembly16 includesuprights38 withhinge attachment apertures40 andstrap apertures42 formed therein. Straps20 includestraps20athat are used to tightenleg assembly16 andstraps20bthat are used to tightenbase26.Insole22 is positioned onbase26 while coveringfoot platform12. Locatingdevice24 is interposed betweenfoot platform12 andinsole22, as discussed below. Preferably, locatingdevice24 andinsole22 are constructed of foam. Even more preferably, the durometer hardness of locatingdevice24 is higher than the durometer hardness ofinsole22.
• FIGS. 2 and 3illustrate insole22 to include anouter edge44, arear portion46, and afore portion48. As best seen inFIG. 4, locatingdevice24 includes atop surface50, abottom surface52, aninside surface54 defining anotch56, a curvedrear surface58 defining arearward portion60, and aforward portion62 having aforward surface64.
• Curvedrear surface58 andouter edge44 atrear portion46 ofinsole22 are formed to contourlip28 such thatinsole22 and locatingdevice24 are restrained from lateral movement withinfracture walker10, as best seen inFIGS. 3 and 4. In this manner, insole22 and locatingdevice24 can be positioned withinfoot platform12 without the use of a guide or tool. Preferably,insole22 and locatingdevice24 are affixed together and tofoot platform12 with an adhesive to prevent relative movement therebetween.
• When assembled,straps20aare threaded through thestrap apertures42 ofuprights38, as best seen inFIG. 1. Eachstrap attachment aperture32 has achafe72 attached thereto.Straps20bare threaded throughchafes72.Straps20aand straps20bare used to restrain the lower leg and the forefoot as discussed below.Hinge assemblies14 attachuprights38 andframe members30 viahinge attachment apertures40 andhinge attachment locations34. Preferably, hingeassembly14 can be either locked to restrain flexion by the ankle, or restrained in such a manner as to allow a certain degree of dorsiflexion and/or plantarflexion of the ankle when positioned within the fracture walker. Such hinge assemblies are well known in the art and, therefore, are not described in detail herein.
• FIG. 2 illustrates a cutaway view of a partiallower extremity78 within afracture walker10 wherein aleft ankle80 includes acalcaneus82, atibia84, afibula86,ligaments88, andflesh portion90.Left ankle80 is supported byfracture walker10 onbase26. Preferably,liner18 is form fitted about thelower extremity78.Liner18 is placed aroundleft ankle80 in order to provide a degree of cushioning and prevent chafing of the skin.Frame members30 are shown to define a medial-lateral heel space96adjacent calcaneus82 that is roughly twice the width at the base ofleft ankle80. The heel space96 allows the calcaneus82 to invert and evert by anatomical rotation relativeleft ankle80.Tibia84 andfibia86 are shown to fit withinleg assembly16 andframe members30 offracture walker10 with relatively less medial-lateral ankle space when compared to the heel space96.Left ankle80 rests withinliner18 oninsole22 which is above locatingdevice24. Locatingdevice24 is positioned such that thenotch56 is located directly belowcalcaneus82. As the weight of a patient is applied throughankle80 andcalcaneus82 ontoinsole22 and locatingdevice24,notch56 allowsinsole22 to flex downwardly such that a portion of theinsole22 is displaced into thenotch56, thereby forming a depression in a portion ofinsole22. This displacement ofinsole22 results in at least a portion ofleft ankle80 withliner18 attached thereon to reside in the depression. This depression is spaced fromframe members30 and inhibits medial-lateral movement ofcalcaneus82 as medial-lateral forces are translated fromcalcaneus82 throughflesh portion90,liner18, andinsole22 toinner surface54 of locatingdevice24. Thus, theankle80 is allowed heel space96, but is correctly positioned by the locatingdevice24 during the calcaneus82 weight bearing portion of walking.
• When use of afracture walker10 is desired, the patient places thelower extremity78 inliner18. Preferably,liner18 is a flexible, cushioned cloth member that is wrapped around thelower extremity78 with overlapping portions.Liner18 may include a plurality of hook and loop type stays to retain the position ofliner18 relative tolower extremity78.Lower extremity78 is then placed infracture walker10 and straps20 are tightened to snugfracture walker10 to the lower limb and forefoot.
• As best seen inFIG. 2,fracture walker10 will allow free medial-lateral rotation of the calcaneus82 during non-weight bearing phases of walking. Thus provided, locatingdevice24 provides a system to locatecalcaneus82 during heel strike and weight bearing without unnecessarily restrainingcalcaneus82. As will be appreciated, locatingdevice24 also provides a one-size-fits-all solution for locating thecalcaneus82, thereby eliminating the need for locating devices of various shapes. Additionally, locatingdevice24 can be cut from sheets of adhesive-backed foam for installation or retrofit into fracture walkers, thereby simplifying manufacture and installation.
• FIG. 5 shows an alternate embodiment of locatingdevice24 illustrated as locatingdevice124 including atop surface150, a bottom surface152, aninside surface154 defining anotch156, a curvedrear surface158 defining arearward portion160, and a forward portion162 having aforward surface164. Insidesurface154 intersectstop surface150.FIG. 6 shows an additional alternate embodiment of locatingdevice24 illustrated as locatingdevice224 including atop surface250, a bottom surface252, aninside surface254 defining anotch256, and a curvedrear surface258 defining arearward portion260, and aforward portion262 having a first forward surface264 and a secondforward surface266. As will be appreciated,top surfaces50,150, or250 and/or side surfaces54,64,154,164,254,262 or266 can be beveled to provide a differing contour ofinsole22 when weight is applied.
• The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Claims (17)

1. A fracture walker comprising:

a foot platform having a base;

an insole covering said base; and

a locating device interposed between the foot platform and the insole, wherein the locating device has a fore portion, the fore portion having a notch therein extending to a forward surface, wherein the locating device is adapted to locate a calcaneus within the fracture walker.

2. The fracture walker ofclaim 1, wherein the durometer hardness of the locating device is greater than the durometer hardness of the insole.

3. The fracture walker ofclaim 1, further comprising a flexible liner, wherein the liner is interposed between a human lower extremity and the fracture walker.

4. The fracture walker ofclaim 1, wherein the locating device is constructed of polyethylene foam.

5. The fracture walker ofclaim 1, wherein the insole is constructed of polyethylene foam.

6. The fracture walker ofclaim 1, further comprising a lip formed on said platform wherein the lip is adapted to abut the insole on said platform.

7. The fracture walker ofclaim 1, wherein the locating device is adapted to accommodate the calcaneus of either a left foot or a right foot.

8. A method of locating a calcaneus within a fracture walker comprising:

providing a locating device for use with the fracture walker, the locating device being adapted to correctly locate the calcaneus laterally within a medial-lateral heel space adjacent the calcaneus within the fracture walker.

9. The method ofclaim 8, wherein the calcaneus is correctly located by forming a depression.

10. The method ofclaim 9, wherein forming the depression includes forming a notch within a locating device, wherein the locating device includes a generally flat body with a top surface, a bottom surface, and a fore portion, wherein at least the top surface and fore portion define the notch.

11. The method ofclaim 10, wherein the notch extends to the bottom surface.

12. The method ofclaim 10, further comprising:

positioning the locating device within a fracture walker, wherein the bottom surface of the locating device is generally horizontal.

13. The method ofclaim 10, further comprising:

positioning an insole within the fracture walker, wherein the locating device is interposed between the insole and the fracture walker.

14. The method ofclaim 13, wherein forming the depression includes:

displacing a portion of the insole into the notch.

15. The method ofclaim 10, further comprising:

positioning an ankle within the fracture walker, wherein the ankle includes the calcaneus and the locating device is interposed between the ankle and the fracture walker, and the calcaneus is located generally above the notch.

16. The method ofclaim 9, wherein forming the depression includes:

applying a force through the calcaneus to the fracture walker such that the force forms the depression.

17. The method ofclaim 9, wherein the depression is formed within an insole.

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