Skip to main content

The Custom Total Contact Cast to Offload Foot Ulcers in the Presence of Biomechanical Deformities: A Case Report

Case Report

The Custom Total Contact Cast to Offload Foot Ulcers in the Presence of Biomechanical Deformities: A Case Report

Index: Wound Management & Prevention 2021;67(3):12–20. doi:10.25270/wmp.2021.3.1220

Abstract

BACKGROUND: Although offloading foot ulcers with a total contact cast (TCC) remains the cornerstone of managing these wounds, the TCC is underutilized. Patient intolerance and potential iatrogenic complications due to TCCs’ general lack of customizability and the inability to address flexible biomechanical deformities that are not in the sagittal plane may be one of the reasons patients with foot ulcers do not receive this crucial component of care. PURPOSE: To describe the use of a novel approach to the standard TCC technique that uses strategic padding to potentially increase patient compliance and comfort while decreasing the likelihood of iatrogenic ulceration, as well as to correct flexible frontal plane biomechanical deformities with casting tape that is pulled medial to lateral, or lateral to medial, to bring the plantar surface of the foot to neutral position. METHODS: The custom total contact cast (C-TCC) was used in a 54-year-old woman who had diabetes, obesity, and a flexible cavovarus foot type with a recurring plantar fifth metatarsal base wound. Weekly debridement followed by silver dressings and C-TCC application were performed. The latter included strategic padding, 2 forms of plaster of paris with contouring, fiberglass, and medial-to-lateral positioning of the foot during application. RESULTS: This case study describes two (2) treatment episodes, with a focus on the second episode. At initial presentation, the ulcer took 5 weeks to heal. During the second treatment, a 48.7% reduction in wound volume was noted after 1 week. By the fourth week of treatment, a 98.7% wound volume reduction was achieved. By the ninth week, the ulcer epithelialized completely. At 1-month and 12-month follow-ups, the site remained fully epithelialized. No iatrogenic ulcerations, cast discomfort, or ambulatory dysfunction were reported by the patient. CONCLUSION: In this case, the C-TCC helped address flexible frontal plane deformities and facilitated healing. Randomized, controlled clinical studies to evaluate the safety and effectiveness of different TCC methods are needed to guide care and improve the utilization of optimal offloading methods for the management of plantar foot ulcers. 

Introduction

Offloading is a key element in the treatment of diabetic foot ulcers (DFUs) and, according to the International Working Group on the Diabetic Foot, a nonremovable knee-high offloading device is the first choice for offloading DFUs.1 The total contact cast (TCC) is a rigid, nonremovable molded cast spanning from the foot to just below the knee that maintains contact with the entire plantar foot and lower leg; this immobilizes surrounding joints and soft tissue while allowing the patient to remain ambulatory.2 A TCC offloads pressure on the prominent areas of the plantar foot that are prone to skin breakdown and ulceration, and a retrospective study by Fife et al3 and a meta-analysis by Elraiyah et al4 demonstrated high healing rates of pressure-related DFUs with a TCC when compared with DFUs not treated with a TCC, such as removable cast walkers, therapeutic shoes, and conventional wound care therapy. TCC use is relatively safe because iatrogenic ulceration due to TCC use is rare. A consecutive series by Guyton5 found an iatrogenic ulceration rate of 5.52% across 398 consecutive casts applied, and these ulcers were typically minor and resolved before a primary ulcer occurred. Nonetheless, many practitioners avoid TCC use partly due to fear of causing an iatrogenic ulcer, and this complication may contribute to less effective forms of offloading being utilized. In a retrospective study of offloading DFUs, Fife et al2 investigated 221,192 visits, and only 2.2% of these visits had documented methods of offloading, with 36.8% of the offloaded cases using a surgical shoe and 16% using a TCC. In essence, there is a need to offload DFUs with the TCC, and we believe the risk of complications likely remains a deterring factor in its utilization. 

The TCC was first described, as used by Khan,6 in a case series of nonhealing ulcers secondary to Hansen disease in Sri Lanka (then known as Ceylon). Coleman et al7 adopted the TCC for treatment of DFUs and brought the technique to the United States in the 1960s. Brand modified the technique and reduced the amount of padding to allow the cast to conform to the leg and reduce shearing forces.7 Flexible sagittal plane deformities are addressed with standard TCC systems or the prefabricated roll-on TCC (TCC-EZ; Integra LifeSciences, Plainsboro Township, NJ) by placing the foot 90 degrees relative to the leg to offload plantar foot pressure evenly, which also prevents creating an equinus contracture. Although the sagittal plane is addressed in the standard TCC, neither the prefabricated roll-on TCC nor other modifications of TCCs to treat DFUs directly address flexible frontal plane deformities. Most of the known TCC application methods, including the method patented by Jensen and Gillin,8 lack versatility during application to properly address biomechanical deformities in multiple planes. The custom TCC (C-TCC) technique, introduced in this article, provides the ability to offload pressure-related DFUs by tailoring to patient-specific biomechanical deformities, such as in the current patient who had a flexible cavovarus deformity.  

An example depicting the need for C-TCC is shown in a patient with a history of a transmetatarsal amputation (TMA) with a pressure-related DFU treated with the prefabricated roll-on TCC, which is applied more readily in clinics than are standard TCCs.2 Although the prefabricated roll-on TCC may be less time-consuming and technically easier to apply than the C-TCC, it lacks the necessary customizability required for such a case. In the authors’ experience at a dedicated wound care center, a prefabricated roll-on TCC size 3 may be appropriate for the foot with a TMA but may be unbearably tight at the leg, or a prefabricated roll-on TCC size 4 may be adequately tight on the leg but lack the necessary contact required at the level of the foot with a TMA. Furthermore, patients in an acute phase of Charcot neuroarthropathy may present with flexible frontal plane deformities and benefit from the C-TCC technique described. The C-TCC technique ensures a potentially greater uniform contact between the leg and foot with the cast in patients with gross biomechanical or anatomical deformities. 

This article introduces a modification of the standard total TCC—the C-TCC—designed to better address frontal plane biomechanical deformities along with a unique padding technique to increase patient comfort and tolerance of the nonremovable knee-high cast and decrease friction along bony prominences, potentially decreasing the risk of iatrogenic ulceration.

Methods

The C-TCC was used in a 54-year-old woman who had diabetes, obesity, and a flexible cavovarus foot with a recurring wound at the plantar fifth metatarsal base. Informed consent was obtained before the initiation of treatment at the Healogics Wound Care Center at Montefiore Mount Vernon Hospital, Mount Vernon, NY. The patient consented to treatment in addition to photographic documentation of the wounds, which were added to the patient’s chart for monitoring the healing process, measuring treatment outcomes, and educational purposes. All patient identifiers were excluded from this case report to maintain anonymity. 

Each clinical encounter spanned 45 minutes for treatment, which included removal of the existing cast and dressings, wound measurement and cleansing, wound debridement, wound and cast application. An experienced clinician, with the help of an assistant, can apply the C-TCC in 10 minutes (15 minutes if no assistant is available). It takes approximately 5 minutes for the final layer of fiberglass to dry before the surgical shoe is applied, and the patient may then begin ambulation. The total time for application and cast drying was 15 to 20 minutes.

Weekly debridement, 1-week dressings, and cast applications were performed under the supervision of a single physician. Casting materials were used from a plastic and synthetic TCC system (Cutimed Off-Loader Select Total Contact Cast System; Essity, Stockholm, Sweden). The C-TCC is made from a combination of general casting and dressing supplies with attention to application technique. The cast is not currently a marketed product because it focuses on technique rather than product. The progression of the wound and timeline of healing were documented and analyzed through i-Heal, an electronic medical record system used by Healogics (Jacksonville, FL).

C-TCC application technique. After sharp debridement, obtaining adequate hemostasis, and completing local wound care, the plantar ulcer is dressed with a sterile, nonadhesive 4" × 4" foam dressing and secured with wound closure strips or nonreactive paper tape. The patient is placed in a comfortable seated position in the examination chair, and a cotton stockinette is slipped over the foot and lower leg. The stockinette should extend proximally to the level of the knee and distally several inches beyond the digits. Adhesive felt padding (1/8") is secured as a strip along the anterior tibial crest down to the dorsum of the metatarsals and as 2 circles to the bony prominences of the medial and lateral malleoli. Excess stockinette at the digits is folded over to the dorsum of the foot, with at least a 1-cm width between the toes and excess stockinette. 

Next, an adhesive, perforated, open cell foam is secured to the distal digits from plantar to dorsal with at least a 1-cm width between the digits and foam. Excess foam is trimmed medially and laterally to conform to the forefoot. To ensure proper padding and reduce friction from the cast, abdominal (ABD) pads are layered along the dorsum of the foot and anterior tibia. A heel pad (made by creating 2 slits on either side of an ABD pad) is applied to the heel, protecting the calcaneus and Achilles tendon (Figure 1). 

A 4" roll of Webril cast padding (AliMed; Dedham, MA) is laid on circumferentially from the distal to proximal foot, locking the ankle. The next roll of 4" padding starts 2 finger-widths from the fibular head (or just inferior to the tibial tuberosity) and extends distally to meet the ankle. A final roll of padding is applied to the foot, ensuring the distal forefoot is protected medially and laterally. The proximal stockinette at the knee is folded down over the padding layers to create a protective edge. Special attention is paid to avoid any wrinkles throughout the process to ensure proper conforming structure and molding to the lower extremity. 

The patient is repositioned to a flat, prone position with the lower leg flexed at the knee and the foot in neutral position, with the ankle placed at neutral or slightly plantarflexed depending on ulcer location and etiology. If the patient cannot be in a prone position during C-TCC cast application, the cast may be applied with the examination chair elevated and the affected leg hanging off the side of the chair, such that the knee is flexed 90 degrees and the foot is not in contact with the weight-bearing surface. The same order of application for the C-TCC is executed, and an assistant may be required to maintain a neutral position and ensure patient saftey if the cast is applied in a seated position. A posterior splint spanning the length of the proximal edge at the posterior leg to the distal plantar forefoot is made out of 1 roll of 4" plaster of paris. The posterior splint is wetted and excess water is removed. The splint is applied and constantly molded closely to the lower extremity. Additional strips of plaster are applied to fill the arch and to correct any structural deformities of the foot (Figure 2). 

First, a roll of 4" elastic-plaster is applied circumferentially to the foot and up the leg. If any flexible frontal plane deformities exist, the casting tape is pulled medial to lateral, or lateral to medial, to bring the plantar surface to neutral position. A standard roll of 4" plaster is applied on top in similar fashion, and a final third layer of standard plaster is conformed to the foot and leg. During the curing process, all layers are molded to the leg without wrinkles while maintaining proper position and a plantigrade surface. Constant molding of the plaster layers also prevents excessive motion within the cast and allows for optimal redistribution of pressure from the plantar foot to the leg. 

A similar technique is used to lay on the fiberglass layers. First, a roll of 4" fiberglass cast tape is applied from the distal foot to the ankle. Next, a 3" fiberglass roll is applied from the proximal to the distal lower leg. A final roll of 3" fiberglass is applied to the foot to secure all layers and ensure a flat, plantigrade surface with a strengthened construct. A minimum of 3 fiberglass rolls are recommended depending on foot and leg size. The foot is held in the corrected position until the fiberglass layers are dry. 

A stockinette is used to cover the entire cast to prevent irritation to the other lower extremity, and a surgical shoe is applied for assistance in ambulation (Figure 3). Gait is analyzed before the patient leaves to ensure proper cast positioning and prevent falls due to possible instability caused by the added height and weight of the cast. The C-TCC is worn for 1 week and must be removed at a follow-up appointment. A standard cast cutter is used to cut the cast along the medial and lateral sides of the cast from proximal to distal, similar to the standard short-leg cast removal technique. 

Case Report

A 54-year-old obese woman, with a medical history of uncontrolled type 2 diabetes mellitus, hypertension, hyperlipidemia, hypothyroidism, osteoarthritis, depression, and past Jones fracture of the left foot, presented to the authors’ wound care center in June 2019 for treatment of an ulcer of the left foot. The patient was 5 feet, 8 inches tall, weighed 220 lb, and had a body mass index of 33.4 kg/m2. Surgical history included left hallux amputation, partial amputation of left second and third digits, and exostectomy of the left foot. Her medications included atorvastatin, losartan, quetiapine, insulin, fenofibrate, venlafaxine, and levothyroxine. She had a history of allergies to ciprofloxacin and trimethoprim/sulfamethoxazole. The patient did not have a history of smoking or drug use but drank a glass of wine daily.

Ulceration to the left foot plantar fifth metatarsal base first appeared in December 2018 and was treated by a podiatrist using an enzymatic debridement ointment (Collagenase Santyl; Smith & Nephew, Fort Worth, TX). The patient was admitted to the hospital in April 2019 for an infection of the ulcer that required treatment with intravenous antibiotics. During that admission, magnetic resonance imaging was performed; results indicated marrow edema with cortical thickening of the base of the fifth metatarsal with inflammatory changes of the subcutaneous fat laterally. The differential diagnosis included osteomyelitis and a healing fracture. A subsequent bedside bone biopsy was performed with negative results for acute or chronic osteomyelitis. Tissue culture from a bone specimen yielded no growth. Wound swab culture results were positive for methicillin-resistant Staphylococcus aureus. After discharge from the hospital, the patient was referred to the wound care clinic where she was treated using weekly debridement, silver dressings, and C-TCC. A new wound culture showed few beta-hemolytic Streptococcus group B. The wound completely epithelialized in 5 weeks, and the patient was discharged from wound care services. Follow-up visits were conducted by the patient’s private podiatrist. 

Almost 2 weeks after discharge from the wound care clinic in July 2019, the patient underwent open plantar exostectomy of the left fifth metatarsal base with primary closure by the private podiatrist. Due to improper weight-bearing after the procedure, the surgical site dehisced 1 week after exostectomy, leading the patient to present to the wound care clinic again in August 2019 with an open plantar ulcer with positive probe-to-bone secondary to surgical dehiscence. On physical examination, an ulcer to the plantar aspect of the proximal fifth metatarsal base measured 4.0 cm × 3.0 cm × 1.5 cm with a fibronecrotic wound base and hyperkeratotic and macerated borders. No tunneling, undermining, or signs of infection were present. Palpable pedal pulses were noted, and results of a Semmes-Weinstein monofilament test indicated  a loss of protective sensation in the left foot. Weight-bearing examination revealed a varus rearfoot almost exclusively to the lateral aspect of the calcaneus and midfoot. Non–weight-bearing examination showed an internally rotated forefoot and rearfoot with a prominent fifth metatarsal styloid process. The patient had a flexible cavovarus foot type with subtalar joint range of motion limited in eversion. Peroneal muscle strength was 0/5 to the left lower extremity. Postdebridement wound measurements were 4.2 cm × 3.5 cm × 1.5 cm.

Diagnostic evaluation of the left lower extremity found an ankle-brachial index of 0.99. The result of a new wound swab culture was positive for multi-drug resistant Enterobacter cloacae. The infectious disease department was consulted for a recommended antibiotic course based on the culture and sensitivities, and cefpodoxime 200 mg 4 times a day by mouth was prescribed for 10 days. Radiographs were negative for osteomyelitis or new exostosis formation.

The ulcer was treated once a week with a combination of sharp debridement, silver dressings, and C-TCC. A dermal curette and No. 10 blade were used for sharp debridement until healthy, bleeding wound margins were noted. An absorptive silver dressing was applied to the wound prior to applying the C-TCC. The wound dressing varied by week depending on wound conditions, but a silver product was consistently used as the primary or secondary layer (Acticoat-7 [Smith & Nephew], Endoform [Aroa Biosurgery Ltd, Auckland, New Zealand] with Hydrofera Blue [Hydrofera LLC; Manchester, CT], gentian violet, gentamicin, and Dermacol-Ag [DermaRite, North Bergen, NJ]). After application of the dressing, C-TCC was applied to the left lower extremity according to the technique described above. Additional plaster was used to fill the arch to offload the lateral aspect of the midfoot and distribute ground reactive force evenly throughout the cast and the foot. Correction of the flexible cavovarus deformity was achieved by pulling the elastic plaster of paris in a medial to lateral direction during casting. Serial debridement, absorptive silver dressings, and C-TCC were applied weekly until complete epithelialization was achieved (Figure 4). 

At the first day of treatment, 3 weeks after plantar exostectomy, the ulcer measured 4 cm × 3 cm × 1.5 cm. Within 5 days of treatment (August 19, 2019), the ulcer measured 2.8 cm × 2.2 cm × 1.5 cm, which was a 48.7% reduction in wound volume (Table 1). By week 4 (September 11, 2019), the ulcer measured 1.8 cm × 1 cm × 0.1 cm, with a 99% wound volume reduction since initial presentation (Table 1). By the ninth week of treatment, the wound epithelialized completely. After healing occurred, the patient ambulated in a modified surgical shoe with felt-pad offloading as she awaited her Charcot Restraint Orthotic Walker boot. The patient required a total of 10 visits until discharge from the wound care center. At 1-month follow-up in the podiatry clinic, the ulcer remained completely epithelialized, and the patient continued ambulation in her modified surgical shoe with felt-pad offloading. At most recent follow-up 12 months since healing, the patient remains free of any open wounds. No iatrogenic ulcerations, cast discomfort, or ambulatory dysfunction were reported by the patient at any point in the course of treatment.  

Discussion

The difference between the TCC and C-TCC is in the method of application to correct biomechanical deformities and stragetic padding; however, the end purpose and goals are the same, that is, to offload plantar foot ulcers. Thus, the indications and contraindications for the C-TCC method described are consistent with that of a standard TCC. Lavery et al9 and Messenger et al10 only recommend using a TCC in noninfected neuropathic ulcers in the absence of peripheral arterial disease (PAD) because neuropathic DFUs with both PAD and infection have the worst treatment outcomes when TCC is used. The extent of wound depth and infection exist on a spectrum, but a strict contraindication for TCC use is a Wagner grade  3 or greater DFU.5 Another important factor to consider before the application of the C-TCC is the vascular status of the affected extremity. In 2018, Tickner et al11 published a retrospective case series and systematic review of 20 patients with PAD who were treated with TCCs to determine potential cutoff values at which TCCs become an absolute contraindication. The results of the study found that TCC use in patients with PAD is a viable option for treating pressure-related DFUs when ankle pressures are  ≥ 80 mm Hg, toe pressures ≥ 74 mm Hg, ankle-brachial index ≥ 0.55, or toe brachial index ≥ 0.55. 

In addition, a relative contraindication for TCC use is a highly exudative wound. Many wound care specialists will hesitate to apply a TCC or any dressing that is changed weekly on a highly exudative wound and instead elect for daily dressing changes. Modifications may be implemented to apply a TCC in the presence of a highly exudative wound, such as creating a window in the TCC at the DFU site described by Caravaggi et al12 in a consecutive, randomized control trial. However, proper drainage control is crucial as the C-TCC must remain intact for 7 days; alginates with superabsorbent foams and drying agents such as gentian violet should be utilized for wounds with mild to moderate levels of exudation. 

In addition to exudation from wounds causing maceration of the foot while in a TCC, skin abrasions and iatrogenic ulceration may dissuade clinicians from TCC use, although iatrogenic ulceration is rare.5,10 According to an 8-year retrospective review by Owings et al13 of 401 patients with diabetes, iatrogenic ulcerations from TCC use most commonly occur at bony prominences such as the anterior crest of the tibia, lateral and medial malleoli, calcaneus, and the digits. Messenger et al10 mention in their narrative review that padding should be used at bony promiences to reduce the risk of iatrogenic ulceration; therefore, the C-TCC implements targeted padding at the aforementioned sites. In the case report presented here, no iatrogenic ulcerations, cast discomfort, or ambulatory dysfunction were reported by the patient. 

Whereas a forefoot cushioning pad and padding of a leg’s prominences are standard in the application of any TCC or TCC kit, the technique described implements 2 aspects that are standard across all C-TCC applications. First, strategic padding is applied across the anterior crest of the tibia and calcaneus in addition to the standard padding of the prominences. While padding decreases the amount of “total contact” between the leg and cast, it likely decreases the risk of iatrogenic ulceration and increases patient compliance with continued TCC therapy. Second, beyond using the arch-fill described in other techniques, biomechanical deformities are addressed by utilizing the elastic plaster of paris to correct flexible frontal plane varus and valgus deformities of the foot.  

Although the C-TCC technique is more time-consuming, labor-intensive, and technically difficult than a standard TCC or TCC kit, the versatility that this technique’s application provides is highly beneficial for the treatment of pressure-related DFUs with concomitant biomechanical deformities, such as a cavovarus deformity. The C-TCC may also be beneficial in patients with DFUs who have flexible multiplanar deformities, such as an equinovarus deformity after a TMA or foot deformation due to acute Charcot neuroarthropathy.  

Another factor to consider in using the C-TCC is the cost of materials. The cost of a plastic and synthetic TCC system, which includes the majority of C-TCC casting materials such as stockinette, adhesive felt, adhesive perforated foam, 3" and 4" fiberglass, and padding, is $162.58. Additional materials used in the C-TCC, include 4 ABD pads ($0.07 each at $0.28 total), plaster of paris roll ($15.59 each/×3), and surgical shoe ($4.46). This adds approximately $51.51 to the cost, for a total of $215.09 per C-TCC. However, the cost of the prefabricated roll-on TCC, with its proprietary walking boot, is $411.44 per unit. Hence, the C-TCC has the potential to effectively offload DFUs with similar materials costs as other alternatives, such as the plastic and synthetic TCC system, but lower materials costs than the widely popular prefabricated roll-on TCC. 

Limitations

Because this is, to the authors’ knowledge, the only reported case of a patient being treated with the described C-TCC casting method, studies to evaluate its effectiveness and safety are needed. The iatrogenic ulceration rate, peak plantar pressures, risk for infection and amputation, and rate of wound healing are yet to be determined for this technique. Although there was a follow-up period of 12 months, a longer-term evaluation of ulcer recurrence would be beneficial. A controlled clinical study to compare the use of the C-TCC technique and the traditional TCC and prefabricated roll-on TCC is needed to ascertain the safety, effectiveness, efficacy, and cost-effectiveness of each method. 

Conclusion

In this case report, a combination of weekly debridement, local wound care, and application of the C-TCC were used to treat a 54-year-old woman with a recurring plantar fifth metatarsal base wound. During the first treatment episode, the ulcer healed within 5 weeks. At 4 weeks of the second treatment episode, the ulcer size reduced by 99%; by 9 weeks, it was healed completely. The DFU was successfully healed, and no iatrogenic ulcerations, cast discomfort, or ambulatory dysfunction were reported by the patient. 

The C-TCC technique differs from the traditional TCC in that it allows for better contouring and correction of biomechanical deformities, thus maximizing the offloading potential of pressure-induced ulcers. This may be especially beneficial for patients with DFUs who have flexible multiplanar deformities, such as a cavovarus foot described in the case report, equinovarus deformity after a TMA, or deformities noted in acute Charcot neuroarthropathy. Although the treatment outcome of the current case report is promising, further studies are necessary to evaluate the effectiveness and safety of the described TCC technique, and research to compare outcomes of available casting materials and techniques is needed to ascertain their efficacy. 

Acknowledgments

Jacqueline Manzi, RN, clinical nurse manager at the Beale Wound Treatment & Hyperbaric Center, Mount Vernon, NY, provided information related to costs of the plastic and synthetic TCC system, the prefabricated roll-on TCC, and all materials used for the C-TCC. 

Affiliations

Dr. Khan is a third-year podiatry resident, Montefiore Mount Vernon Hospital, Mount Vernon, NY.  Dr. Stoupine is a second-year podiatry resident at Montefiore Mount Vernon Hospital, Mount Vernon, NY.  Dr. Farha is a  podiatry fellow in advanced wound care and tissue healing at St. John’s Episcopal Hospital, Far Rockaway , NY. Dr. Kim is a third-year podiatry resident at Montefiore Mount Vernon Hospital, Mount Vernon, NY. Dr. Klinoubol is an attending physician, Montefiore Mount Vernon Hospital, Mount Vernon, NY. Address all correspondence to: Mohammad Junayed Khan, DPM, 869 Andover Road, Lansdale, PA 19446; email: mjk.dpm@gmail.com. The views expressed in the submitted article are the authors’ own and are not an official position of Montefiore Mount Vernon Hospital, New York, NY.