A Practical Guide to Total Contact Casting: A Risk vs. Benefit Approach

  Total contact casting is an effective and complicated tool in the treatment of neuropathic foot ulcers. In order to gain the most benefit with the least amount of risk one must consider several key variables and, most importantly, must consider the patient as a whole. The following are practical considerations that come to mind when I think about total contact casting after 4 years and a little over a thousand chances to practice and learn.

First Things First

  TCC application requires specific, specialized materials. Each TCC requires a length of stockinette, specially cut ¼” felt to pad the anterior tibial, dorsal foot and malleolar areas, roll cast padding for additional padding around the top of the TCC and ankle area, ¼” adhesive backed foam to cover toes, 1 plaster and 4 fiberglass rolls, a solid foot plate and a rubber walking surface (a cast boot can be used in place of the foot plate and rubber walking surface). In addition to these consumables, a water bucket for submerging plaster and fiberglass rolls and a cast saw (preferably with vacuum) are also necessary. It can be challenging to obtain supplies initially as they are often not available through the same outlets other wound dressing supplies are ordered from. Kits containing all needed supplies are available commercially and may be an easier, albeit more costly, alternative to purchasing products separately. Individual supplies can be found through podiatry or orthopedic supply dealers.

How To

  Technical expertise is vital in the application of TCCs because, although the benefits are considerable and well documented, the risks are significant. It is humbling to think that most of the patients who would benefit from the use of TCC have decreased or absent protective sensation, impaired proprioception and likely some degree of small vessel disease. In order to prevent movement in the cast, minimal padding is used. In addition, the wound is unable to be monitored or dressings changed for up to a week at a time. All of these elements demonstrate just how important careful patient assessment and excellent technique in TCC application are. Anyone endeavoring to apply a TCC should first have both didactic and hands on training. The experience and feedback gained by applying a TCC on a colleague and, even better, having one applied to you is invaluable in developing technical skill. There is nothing that reminds you to make sure your angles are accurate and cast smooth more than the kinesthetic memory of hobbling around on a lopsided cast with an uncomfortable rough spot. Even a small amount of difference in angles from neutral can make walking difficult and even a small rough spot can cause a new wound.

Considerations

  Medical, environmental, mobility and psychosocial factors should all be considered and assessed on an ongoing basis.

  From a medical standpoint, the patient should have adequate blood supply. Understanding that most diabetic patients with foot ulcers have some impairment of blood supply, it is practical to ensure that everything has been done to optimize the vascular status (ie, vascular consult and/or intervention) and then weigh risk vs. benefit. It should be noted that even patients that show no abnormality on a routine vascular exam could have small vessel disease. This may only become apparent when the wound doesn’t respond as it should or new areas of necrosis show up in telltale “arterial” areas such as over the proximal or distal 5th metatarsal. If wounds worsen or anything other than a minor irritation occurs while the patient is in a TCC, this should tip the scales toward the risk side of risk vs. benefit and use should be reconsidered until the underlying problem is identified and addressed. Significant wound depth should trigger a work up for abscess or bone infection. In general, soft tissue infection and osteomyelitis have to be considered and ruled out or treated. As long as the infection is being treated appropriately and the wound stable, however, the benefit of better off-loading may outweigh the risk of less frequent visualization of the wound. Another less obvious consideration is back and hip pain caused by alteration in gait. This can be related to difference in height between the casted leg and footwear of the opposite leg or the weight of the TCC on one side. Also, it is not uncommon for the cast to cause abrasions on the opposing leg, especially if the patient is an active sleeper. These issues can be allowed for with taller footwear on the opposite leg in the case of height difference or padding via sleeping with a pillow between the legs or wearing a sock on the opposite leg. Neuropathic discomfort can sometimes be heightened with the use of TCC and should be addressed.

  It is important to think about environmental factors such as whether the patient will need to manage stairs, if they will be able to keep the cast dry or if they will need to drive and the wound is on their right foot. TCCs should not be used on the right foot of patients who must drive. It’s also important to warn patients to wear loose fitting pants or shorts so that they’ll be able to remove them over the cast without cutting them.

  General mobility can affect whether a TCC is appropriate or what type of walking interface is used. On one hand a rubber footplate that’s built into the cast is stable in the sense that it doesn’t move or separate but it is small. If you are using a built in footplate it is helpful to educate your patients to take a shorter step and land with their foot flat, therefore engaging the rubber footplate, rather than landing slippery heel first. A cast boot offers a larger walking surface but can shift. Some patients prefer a cast boot because they can remove it at night and not get their sheets dirty, but if they forget to reapply or choose not to wear the boot they will be much less stable, particularly on hard surfaces. Failure to wear the cast boot can also affect the integrity of the cast. Patients with prostheses on the contralateral side should be evaluated carefully to determine if balance is adequate, weighing the benefit of protecting the remaining foot against overall safety and mobility.

  Psychosocial issues can include anything from claustrophobia to dementia. A TCC should not be used on someone who is unable to understand safety precautions. Of course, determining this is somewhat subjective and family/caregiver support can offset some deficits. Claustrophobia is a common concern. This can be managed via anti-anxiety medications, relaxation techniques, etc; however, the most effective treatment for this that I’ve found is edema management within the cast. It greatly reduces episodes of “tightness” that are often at the root of patient’s anxiety. It works nicely to add a layer of tubular elastic bandage under the stockinet layer, which is then folded over the upper edge of the cast and fixed in place along with the stockinet. Some patients have difficulty with the “stigma” of wearing a cast and the attention they feel it draws. A discussion about the benefits of TCC vs. the possible complications of the wound not healing can help bring things into perspective.

Patient Education

  Patient education is critical when it comes to the TCC. High on the list of important items is that there should be no movement within the cast and that any discomfort is not OK. It’s important to explain that the patient will often lose volume in the leg due to edema reduction, thus allowing movement in the cast. This is one of reasons the TCC is changed 2-3 days after the first application rather than a week. Because there is already some loss of protective sensation the patient may not feel pain from a rub spot until it is too late. Movement needs to be the cue to come in for a cast change rather than discomfort or pain. In addition, any amount of discomfort, even without movement, should be taken very seriously. The patient must not wait for pain to seek attention but should always err on the side of caution and call or come in with any concern.

  Another key topic is the difference between an orthopedic cast and a TCC. Orthopedic casts have thick padding under the entire surface of the cast. TCCs are different in that they are used while walking. In order to prevent excess movement with gait they have limited padding, focused mainly over bony prominences. This fact becomes most important when the TCC is removed. Most orthopedic casts are removed by cutting along the medial and lateral sides in a bivalve-type fashion. The bulk of a TCCs padding is along the anterior tibial, dorsal foot, toe and malleolar aspect with almost no padding along the medial and lateral calf and foot. Therefore, a TCC should not be cut off as if it was an orthopedic cast, and the patient should understand this well enough to alert anyone removing the TCC about this. Even a skilled orthopedic technician can cause serious injury removing a TCC incorrectly. One way to help ensure a TCC is removed correctly is to actually draw cut lines on it before the patient leaves the clinic (see photos). Even if the person removing the cast has never seen a TCC before it should be a cue that this cast is “different” and more information is needed. It is helpful to provide the patient with a written explanation that they can carry with them to show caregivers (one commercially available kit has a patient handout with a wallet sized tear-off).

  Patients should be educated that the first few steps with the TCC will be awkward, even if they are used to wearing them. Because it’s impossible to make all of the angles exactly the same with every application, each new TCC feels a little different. It’s a good idea to stand by as the patient stands and takes steps for the first time and make sure an assistive device is available if needed.

Other Notes

  Though TCC is most often used to treat diabetic foot ulcers other types of wounds can benefit. Patients with spasticity in addition to neuropathic wounds may benefit from increased range of motion as well as offloading. In this case the TCC also acts as a serial cast. In situations where fixation is needed the TCC acts as an immobilizer while still allowing ambulation.

  For patients that have had a transmetatarsal amputation it is still possible to use TCC. The main modification needed is an adjustment of the foam used to cover the toes. Typically the adhesive backed ¼’ foam is folded over the toes in sandwich fashion and the ends of the foam are trimmed, leaving the entire toe area enveloped in foam. If one were to fold the same size foam over a TMA, the edge of the foam on the plantar surface would be over a weight-bearing surface. When the TCC was applied it would leave a “ledge” at the point where the plaster/fiberglass contoured to fit over the foam, thus causing an uneven surface over a weight-bearing surface. If the foam was not used (as no toe protection is needed) it would be difficult to remove the TCC because this is an area that must be cut. The solution is to cut the foam lengthwise and apply it along just the front and sides of the foot in “bumper" fashion. This leaves you with no ledge and a protected cutting surface.

Deal Breakers

  It should be noted that there are certain situations that I would stop use of or not apply a TCC. The first, as noted above, is a worsening of the wound or development of a new wound over a bony prominence. Second is patient compliance with appointments or safety (see photos). TCCs carry enough risk; applying one to someone who has already missed three weeks worth of appointments, someone who has removed their own cast with a kitchen utensil or power tool or someone who consistently returns to the clinic “swimming” in their broken down, waterlogged cast is just not wise (sorry to say these examples are not arbitrary). Also, a sudden or relatively sudden change in mental status is a serious safety and medical issue and should be worked up before continuing the use of TCC.

In Conclusion

  In this difficult to treat population options are not always black and white. Many factors have to be continuously considered and assessed. Though I’m sure that this list is not exhaustive, I’ve written about the things that are helpful for me to focus on and remember, and a few little tricks I’ve learned along the way. Fortunately, I’m also a part of a multidisciplinary team of caring, smart professionals that work collaboratively with the same “whole patient,”risk vs. benefit approach. Challenges are a given with use of the TCC, but they can often can be overcome with forethought, creativity, good patient education and an honest assessment of the patient’s abilities.

  Melodie Blakely, PT, MS, CWS is the Clinical Coordinator for The Wound Healing Center of Osceola Regional Medical Center in Kissimmee, Florida and can be reached at melodie.blakely@hcahealthcare.com.