1.  Field of the Invention
This invention relates to a method of preparing a patient's leg, to which an external fixation assembly is applied to prepare the patient's leg for healing, for ambulation through the use of a foot assembly. 
2.  Background Art
External fixation is a process used to facilitate healing of certain types of bone fractures and treat various foot and ankle pathologies. 
One form of external fixation utilizes an external fixation assembly, consisting of plural frame components that are operatively interconnected.  Pins, screws, and/or cables extend from the frame components through a patient's soft tissue and into his/her bones to effect setting at a fracture site and/or immobilize or strategically orient the foot to promote healing thereof. 
Once the external fixation assembly is put in place on a patient's leg, it is generally preferred that the patient engage in weight bearing activity that has proven to stimulate circulation and promote healing.  For example, ambulation causes micromotion at a fracture site that advances healing. 
Heretofore, it has been common to wrap the patient's foot, as with several layers of a heavy cloth, typically of a type used to form towels, that are held in place as by an outer retaining wrap.  During ambulation, the patient applies his/her weight to a cushioning accumulation of cloth in the wrap that does not have a bearing surface of consistent shape or resiliency.  As a result, during ambulation, the bearing forces may be unpredictably transmitted, potentially in a detrimental manner through the patient's leg.  This may cause patients to avoid prescribed regular ambulation. 
The patient may also be unstable in bearing his/her weight upon the wrap, potentially leading to a detrimental twisting of the body, or worse yet, a fall.  Adaptation on the user's part to this type of wrap may lead to muscular compensation that introduces other complications that may develop over a typical six to twelve week recovery period.  Whereas, ideally the physician would be able to prepare the patient to ambulate consistently in a manner that optimizes healing, this is not possible with the above practice, or utilizing known alternatives. 
A further problem with the above wrapping procedure is that it may be difficult or impossible to effect wrapping in a manner whereby the patient is consistently comfortable and healing is promoted.  The initial wrapping procedure is generally carried out at a physician's office.  As the patient ambulates, the wrapped materials may loosen and/or shift, which could lead to discomfort and potentially tissue pressures that may not be conducive to healing.  Many patients do not feel competent to effectively re-wrap the foot and thus face the options of either living with the compromised wrap or contending with the inconvenience of seeking medical assistance. 
Still further, with the patient's foot wrapped, access to the sites at which the pins and/or cables penetrate the soft tissue is obstructed.  These sites are prone to infection without proper treatment, that is commonly neglected. 
The above-described wraps also act as insulators, thereby maintaining elevated body temperatures that can be detrimental to healing.  Whereas it might be optimal to lower the tissue temperature, this is often impractical through the cloth layers of the wrap.  A patient's alternative is to remove the wrap, apply a cooling pack, and thereafter replace the wrap.  Even if this inconvenience is contended with, the resulting cooling becomes very limited in terms of its duration and effect. 
A still further problem is that the wraps do not lend themselves to re-use.  Each time the wrap is removed, it is most practical to effect replacement thereof.  Aside from the fact that it is necessary to keep on hand significant supplies of the wrapping material, it is also difficult for a patient to effectively re-wrap the leg without assistance. 
Still further, the wrap, aside from its detrimental insulating qualities, generally is applied so that it creates a relatively sealed environment over the soft tissue.  By reason of there being no, or limited, ventilation, perspiration may cause a sustained accumulation of moisture that could inhibit healing and potentially lead to fungal generation. 
Because of the many problems, noted above, patients that have an external fixation assembly applied have generally avoided ambulation.  This has lead to lengthened recovery time, poorer patient morale, and oft times to other complications associated with inactivity.