Serial casting of the lower extremity to correct contractures during the acute phase of burn care.

The management of a patient with major injuries due to burns is a challenge to the entire burn team. Physical therapy and occupational therapy begin at the time of admission to the hospital and continue through scar maturation. Treatment interventions include positioning, splinting, range of motion (ROM) exercise, therapeutic play activities, ambulation, scar management, and family-patient education. The primary goals of treatment are to prevent deformity, to facilitate optimal function, and to promote reintegration into society.[1-3]

Contracture and scaning are among the sequelae of a major injury due to burns that can limit quality of life and function.[4] Children are more susceptible to scar contracture development than adults.[5-7]In the acute phase of care for the patient with burns, there is great risk of contracture development, especially when a full-thickness burn involves an extremity circumferentially. Edema and inelastic eschar may compromise lymphatic and vascular flow, which can lead to distal ischemia.[8] Subsequent contracture development and muscle necrosis can result.[8] In the postacute phase, contractures are most often due to contractile forces within a developing scar.[9]

In children, the long-term sequelae of a contracture may involve the alteration of bony development and can limit a child's ability to function.[10] Proper positioning of children with burns is a challenge due to their small body size, activity level, and inability to cooperate with a positioning program. Unlike adolescents or adults, it is difficult for children to understand why it is important to exercise against restricting, painful wounds or scars.[11]

Lower-extremity plantar-flexion contractures that develop during the acute phase of burn care are difficult to manage with traditional treatments. Static (thermoplastic) splints often do not conform enough to hold the foot and therefore cannot be used to serially progress to a neutral position. Springs and rubber bands can be added to static splints to provide greater stretching force. During the acute phase of burn care, however, these types of splints may not be indicated because of the excessive edema and lack of patient cooperation.

Serial casting has been reported to be successful in treatment of joint contracture in patients with central nervous system disorders and orthopedic conditions.[12,13] These patients are at risk for developing soft-tissue contracture as a result of maintaining a position for a prolonged period of time. When treatments such as passive ROM, positioning, and splinting have failed to correct contractures, serial casting can be effective in progressively increasing ROM.[14-16]

Connective tissue behaves in a viscoelastic manner under tension and is therefore influenced by the amount of applied force, duration of applied force, and tissue temperature.[17] The use of low-force, long-duration stretching to enhance permanent plastic deformation of connective tissue has been documented.[17] Immobilization of muscles in a lengthened state brings about changes in the number of sarcomeres, the length of the sarcomeres, and the length-tension relationship of the muscle.[18,19] Additionally, casting has been shown to assist healing of wounds that develop secondary to diabetes,[20] but some therapists have reported that serial casting over open wounds may be contraindicated.[21]

Casting has been used in patients with burns for postoperative immobilization to prevent graft movement and to minimize scar contracture formation during the remodeling phase of healing.[22] Ricks and Meagher[23] have reported that immobilization casting following skin grafting in a child decreased the number of physical therapy treatments, improved wound closure, and decreased healing time. Serial casting has been used successfully on outpatients with burns when ROM is limited due to scar tissue.[24] In the management of children, serial casting is effective because they are not able to remove the casts themselves.[25] The use of serial casting as an effective treatment of contractures that develop during the acute phase of recovery from a burn has not been previously reported. This case report demonstrates the use of serial casting in allowing for wound healing while correcting plantar-flexion contractures that developed early in the care of a major burn.

Case

The patient, a 2-year-old boy, sustained a 49% total body surface area (TBSA) circumferential scald burn from the costal margin distally involving the torso, buttocks, and bilateral lower extremities when immersed in hot bath water. The patient was treated at a community hospital and transferred to our regional burn center on postburn day 1 in critical condition. The significant aspects of the child's medical course included an absent right dorsalis pedis pulse by Doppler examination, hyponatremia, and a basilar pneumothorax. He also experienced a seizure and an episode of transient left wrist-drop. The patient underwent six tangential-excision/split-thickness skin grafts to the buttocks and both lower extremities from postburn day 8 to 61.

According to the patient's family, the child was active, verbal, and ambulating appropriately before the burn. Throughout the child's stay in the intensive care unit, he remained awake with eyes open but nonverbal, withdrawn, and rigid without spontaneous movement. The initial rehabilitation evaluation was deferred secondary to his unstable medical status until postburn day 8, when he had his first skin graft to both lower legs. Upon evaluation, the patient was found under anesthesia to have normal passive ROM, except for bilateral ankle plantar-flexion contractures of 45 degrees from neutral. At that time, the short-term goals were to immobilize the patient for skin graft protection and to use splints to prevent further loss of ROM.

The patient did not tolerate thermoplastic leg splints due to the severity of the contractures. Following a physician-therapist discussion, it was decided to immobilize both ankles with short leg casts for 5 days postoperatively. After this immobilization period, the reevaluation revealed normal active-assisted ROM of all four extremities except for both ankles. The patient had 45 to 60 degrees of plantar flexion in the right ankle and 40 to 50 degrees of plantar flexion in the left ankle. He was dependent in all functional activities. The rehabilitation goals were to prevent further contracture, maintain ROM, and facilitate active motion. For the next month, the patient's medical status remained critical. The rehabilitation program consisted of positioning, postoperative casting, ROM exercises, activity as tolerated, and family education.

As the child's medical status improved, the rehabilitation goals were modified to include increasing bilateral ankle dorsiflexion ROM, facilitating age-appropriate movement, and preventing scar contractures. The treatment program was expanded by incorporating lower-extremity serial casting to lengthen the triceps surae muscles, mobility and gait training, therapeutic play, and scar management.

The serial casts to increase ankle dorsiflexion were applied on postburn day 50. At that time, the patient continued to have 45 to 60 degrees of right ankle plantar flexion and 40 to 50 degrees of left ankle plantar flexion. The program lasted 2 months, during which the patient progressed and his ankle ROM improved (Table, Fig. 1). The patient's skin healed during the casting program, with only one incident of skin irritation due to the use of a silicone insert under the cast. The casts were changed twice a week, and the final holding casts were in place for 7 days. The patient gradually tolerated an upright position, weight bearing, and ambulation.

[TABULAR DATA OMITTED]

On postburn day 120, the patient was discharged from the hospital to a pediatric rehabilitation facility. At that time, he was verbal and participated socially. He ambulated with ankle-foot orthoses (AFOs) secondary to generalized muscle weakness. His discharge program consisted of developmental activities, scar management, active and active-assisted ROM exercises, and ankle splints to maintain ankle position. One year postburn, the child's ROM of both ankles allowed movement to neutral. He had continued leg weakness of unclear etiology and was ambulating independently with AFOs.

Technique

The serial casting technique used was adapted from the technique described by Cusick.[26] This technique is different from other immobilization casting because of the padding used for bony landmark protection and the, greater amount of dorsiflexion force applied. Prior to initiating the casting, a physician's consent was obtained along with roentgenograms to determine the status of the joints. The patient was sedated with morphine sulfate prior to casting to decrease pain and to promote patient cooperation. Before cast application, equipment and casting materials were prepared (Fig. 2).

The patient's skin was carefully examined before each casting. At each cast change, the patient received wound care, massage, and ROM exercise. Goniometric measurements were taken, as described by Norkin and White,[27] by one of two therapists. The skin was washed and moisturized with lotion, and any open areas were dressed with an antibiotic and petroleum gauze dressings. The patient was draped in the prone position with the extremity to be casted placed in 90 degrees of knee flexion prior to casting. One layer of stockinette,(*) three times die length of the foot, was applied to the limb. Two slits were cut distal to the foot in the medial and lateral aspects of the excess stockinett so that it could be folded over into th cast later in the fabrication process.

With the ankle dorsiflexed, a layer of cast pad[dagger] was applied extending from the metatarsophalangeal joint to below the knee. Foam pads,[double dagger] 0.8 cm (1/3-in) thick, were secured over bony prominences. The bimalleolar pad was placed over the anterior ankle, ensuring that it covered the lateral and medial malleoli as well as the navicular. The heel pad was then secured onto the posterior lower leg from the triceps surae musculotendinous junction to the plantar surface of the foot. Finally, the proximal pad was placed around the proximal lower leg to protect the tibial shaft. Lengthwise strips of foam[double dagger] were placed along the lateral aspect of the leg to protect against the vibration of the cast saw. An additional layer of cast pad was applied.

Prior to plaster application, the subtalar joint neutral position was visually estimated to promote congruency of the talocural and midtarsal joints and provide stability during weight bearing. With the patient in the prone position and with his knee in 90 degrees of flexion, an additional therapist held the extremity stable by pushing the lower leg toward the patient's body and pulled the stockinette away from the patient's heel in a linear fashion. A downward dorsiflexion force was then applied, with care taken to avoid forefoot varus or valgus caused by poor alignment during the pull of the stockinette.

Plaster of paris gauze strips[dagger] were applied firmly from distal to proximal starting at the metatarsophalangeal joint heads and extending to the calcaneus. The plaster was contoured to the arches of the foot and the posterior aspect of the calcaneus. An individually measured and precut thermoplastic[sections] footplate was placed at the center of two layers of plaster twice the length of the foot. The footplate provided an even surface for heel buildup and a spring for toe-off during ambulation. The top half of the plaster was folded over the distal aspect of the plate. A foam piece was added for cushion below the toes. The entire plate was placed onto the plantar surface of the foot. The excess plaster from the footplate was incorporated into the existing cast. The stockinette was pulled back over the plate and dorsum of the foot. The footplate was secured in place on the foot with one layer of plaster wrap. The shaft of the cast was reinforced with three to four layers of plaster cast material. The dorsiflexion force was maintained by pushing down on the footplate and the calcaneus as contoured to prevent cast slippage. Weight-bearing activity was not permitted for 24 hours.

Discussion

This case report indicates that serial casting may be effective when other methods of positioning and splinting are unsuccessful in remediation of contractures following burns. Despite the unclear etiology of the contractures, the cast provided a sustained stretch in the lengthened position, which increased ROM, improved bony alignment of the entire foot-ankle complex, and allowed for effective wound healing. The apparent success of the technique may be attributed to the collaboration of the burn team for patient preparation and premedication, the maintenance of proper bony alignment during cast application, and consistent cast changes.

When casting the injured body part of a patient with burns, close monitoring of skin condition and wound status is essential. A common complaint of patients with burns is excessive itching as the wound heals, Casting provides a safe medium for healing of wounds and grafts because it prevents the patient from scratching. The use of insert material for scar management under the casts has been documented.[28] Skin tolerance to particular materials, however, must be monitored for each patient.

In this case study, serial casting was used to combat plantar-flexion contractures of the foot and ankle that developed early following a burn injury. Casting is a conservative, cost-effective technique compared with the cost of serially changing thermoplastic materials or surgical release. Casting allows for wound healing and promotes patient compliance, as the cast cannot be removed by the patient and protects the burn from patient scratching. Continued study of the efficacy of this therapeutic modality is necessary to further support its use in the various phases of burn rehabilitation.

Acknowledgments

We thank Delia Gorga, PhD, OTR, Barbara Greenspan, OTR, Michael Madden, MD, Jerome Finkelstein, MD, Cleon Goodwin, MD, and Willibald Nagler, MD, for their assistance in this report and their continued support in burn rehabilitation.

[Figures 1 and 2 ILLUSTRATION OMITTED]

(*) Baxter Healthcare Corp, Deerfield, IL 60015. ([dagger]) Johnson & Johnson Medical Inc, PO Box 90130, Arlington, TX 76004-3130. ([double dagger]) Smith & Nephew Rolyan Inc, Menomonee Falls, WI 53051. ([sections]) WFR Aquaplast Inc, Wyckoff, NJ 07481.

References

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J Johnson, PT, is Assistant Chief Physical Therapist, Department of Rehabilitation Medicine, New York Hospital Cornell Medical Center, Box 142, 525 E 68th St, New York, NY 10021 (USA). Address all correspondence to Ms Johnson.

R Silverberg, PT, is Senior Physical Therapist, Department of Rehabilitation Medicine, New York Hospital Cornell Medical Center.

This case report was funded by the Millburn Foundation.

This article was submitted January 31, 1994, and was accepted December 8, 1994.