1. Apply a foam dressing to the ulcer area and secure the dressing with paper tape. If the sterile package appears to be compromised, do not use it.
2. Place the stockinette over the foot, extending to the knee. Pull the stockinette forward to cover the toes and fold approximately two to four inches over the dorsum of the foot. Trim the excess and secure with plastic tape.
3. Place a strip of felt along the anterior crest of the tibia with flaps covering the malleoli.
4. Fold adhesive foam lengthwise to cover the toes completely, with the top and bottom sticking to the stockinette. Trim the excess from each side.
5. Place the patient in a prone position with the leg flexed at the knee. Apply webril around the leg, overlapping slightly at the shin area.
6. Maintain the foot in a neutral position with the ankle as close to 90 degrees as possible. Be sure not to crimp materials in toes or heel/ankle areas during application.
7. Using a 4-inch roll of plaster, briefly wet the material. Wrap the foot and leg from distal to proximal. All “tucks” or folds of excess plaster should be made over the padded areas only.
8. Wet a 3-inch roll of fiberglass and apply in the same fashion. Wrap the foot and leg from distal to proximal. All tucks or folds of excess plaster should be made over the padded areas only.
9. Fabricate a posterior splint from 4-inch fiberglass without wetting, extending from the toes to the most proximal part of casting material. Place the splint so any excess material hangs over the width of the foot medially and can be rolled inward to fill any void in the arch area.
10. Place 1/4-inch plywood on the bottom of the foot with a walking heel.
11. Fashion another posterior splint with 3-inch fiberglass without wetting and cut in the appropriate place for the walking heel to show through.
12. Apply a final layer of wet 4-inch roll of fiberglass as in step 8 to finish the cast.
13. Do not allow weightbearing for 15 minutes or until the cast has cooled and hardened.
14. Provide the patient with an instruction sheet and an emergency removal instruction card. Instruct the patient to carry the card with him or her in case of an emergency.
A Helpful Primer On Total Contact Casts
Neuropathic foot ulcers are the most common precursor of lower–extremity amputation in patients with diabetes.1 In the podiatry literature, as well as other wound care literature, the total contact cast (TCC) has long been considered the gold standard for treating non-infected, neuropathic foot ulcerations.2 The TCC heals wounds by reducing weightbearing pressure and shear force to the plantar aspect of the foot. The unique well-molded, minimally-padded construct of the cast allows it to maintain “total contact” with the foot and lower leg.
Clinical results overwhelmingly validate the use of TCC in healing neuropathic foot wounds. A study by Armstrong, et. al., involved 63 patients with non-infected neuropathic plantar foot ulcers and compared the TCC with a removable cast walker and a half shoe.3 All patients were followed for 12 weeks and had weekly visits for wound care and debridement. The ulcer healing rate for the TCC patients was 89.5 percent, compared with 65 percent for patients treated with the removable cast walker and 58.3 percent for patients treated with a half shoe.
Mueller et. al., also compared the TCC with another treatment modality.4 Patients were randomized to receive TCC treatment or to avoid weightbearing and use sterile saline wet-to-dry dressings. Ninety percent of the TCC group healed within 42 ± 29 days, whereas only 67 percent of the non-TCC group healed within 65 ± 29 days.
Myerson et. al., reviewed previous reports of TCC therapy and found a combined average healing rate of 75.5 percent after an average of 38.7 days in the cast.5 In their study, 90 percent of 71 ulcers were healed at a mean of five and a half weeks.
We have used TCC extensively in our wound care clinic over the past 10 years and have applied more than 2,100 casts in the past three years alone. Despite the efficacy of the TCC, it is a modality that is still not widely used. One of the main reasons for this is the lack of standardization in application technique and materials. With this in mind, we’ve provided a thorough overview of the TCC, including detailed explanations of its application and removal. We hope to not only illustrate that the TCC is a beneficial addition to any wound care practice, but dispel some of the myths impeding its use.
Reducing Peak Plantar Pressures
Ambulatory short leg casts were first introduced by Kahn and Paul, who developed the technique in the 1930s to treat lepers in India.6,7 In the 1950s, Brand and colleagues embraced the walking cast technique. They reduced the amount of padding and brought it to America.8,9 Today, physicians around the world employ the TCC to treat pedal ulcers related to Hansen’s disease, diabetes and other ailments resulting in insensate feet.
The TCC facilitates ulcer healing by effectively reducing plantar pressures. Birke, et. al., reported that a TCC reduced pressure at the metatarsal heads in six normal subjects by up to 84 percent.10 Hartsell et. al., found a 65 percent reduction in forefoot plantar pressures when comparing the TCC to a running shoe.11 The same study showed excellent reproducibility of load redistribution with TCC applications spaced one week apart and performed by the same technician. Shaw, et. al., demonstrated that the TCC allows one to transfer approximately 30 percent of the weightbearing load directly to the cast wall.12
Several mechanisms contribute to the reduction of peak plantar pressures in the TCC. The TCC is molded to the foot and lower leg in order to redistribute pressures over a larger surface area, including the transmission of body weight to both the heel and the lower leg. This allows for the “cone effect” by which an inverted cone (the leg) makes total contact with a conical receptacle (the cast). In order to ensure that the load bearing forces are effectively transmitted to the walls of the cast, the patient must be casted in this position.
The intimate contact of the cast with the foot and leg also reduces shear forces normally present between the foot and shoe. The TCC alters the patient’s gait by requiring a shortened stride length and a decreased walking velocity. The TCC also eliminates sagittal plane ankle joint motion and the propulsive phase of gait, thereby reducing the forefoot pressures that normally occur with toe-off.