A spica cast is a specialized orthopedic immobilization device that stabilizes the torso and one or both legs. It often covers the body from the chest down to the ankle or foot of the affected limb(s). The cast’s primary purpose is to completely immobilize the hip joint and thigh bone, ensuring proper alignment while injuries or conditions heal.
Defining the Spica Cast
The spica cast is an orthopedic tool designed to hold the hip and thigh in a precise, fixed position. It extends from the upper abdomen or chest down to encompass the pelvis and the legs, including an opening left in the perineal area for toileting and hygiene. Because the hip joint is a major weight-bearing joint, the cast requires substantial rigidity to prevent movement during healing.
There are several configurations based on the condition being treated. A single spica covers one leg entirely and the other only to above the knee, while a double spica cast immobilizes both legs down to the ankles or feet. The cast is constructed using layers of padding and either fiberglass or plaster of Paris, with fiberglass often preferred for being lighter. Many modern spica casts also feature a waterproof, breathable lining, like Gore-Tex, adjacent to the skin to minimize moisture buildup and protect the inner padding from soiling.
Conditions Requiring a Spica Cast
The most frequent use of the spica cast is in managing Developmental Dysplasia of the Hip (DDH), a condition where the hip joint has not formed correctly or the socket is too shallow. For DDH, the cast is used after a closed reduction procedure to hold the head of the thigh bone securely within the hip socket, allowing the joint structures to stabilize and develop correctly.
Spica casts are also the standard of care for treating complex femur fractures in young children, typically those under five or six years old. The cast stabilizes the thigh bone, preventing movement at the fracture site to ensure the bone heals in the correct alignment. They are also used to maintain stability following surgical procedures on the hip or pelvis, providing complete external fixation to protect the repaired bones and soft tissues.
The Application and Removal Process
Applying a spica cast is a careful procedure, almost always performed in an operating room under general anesthesia or deep sedation to ensure the child remains still. The patient is placed on a specialized frame or spica table, which allows the surgeon to position the limbs exactly while the casting material is applied.
The process begins by placing a tubular bandage over the skin, followed by layers of cotton padding. A small folded towel may be placed over the abdomen to create breathing room, which is removed once the cast hardens. The fiberglass or plaster material is then wrapped around the torso and legs, molded to the body’s contours while the hip and thigh are held in the desired position. The duration the cast is worn varies by condition, ranging from about six weeks for a simple fracture to several months for complex hip conditions. When treatment is complete, the cast is removed using a specialized electric cast saw that vibrates rather than spins, safely cutting through the rigid material without touching the skin.
Essential Daily Care and Management
Caring for a child in a spica cast requires significant adjustments to daily routines, focusing intensely on hygiene and skin integrity. The most challenging aspect is managing toileting and preventing the cast’s padding from becoming soiled, which can lead to skin breakdown and infection. Caregivers commonly employ a “double diapering” technique, using a smaller diaper tucked snugly inside the cast opening and a larger diaper worn over the outside to contain any accidents.
Skin checks are a high priority, particularly around the edges of the cast, which should be monitored multiple times a day for redness, chafing, or pressure sores. Caregivers should never insert anything under the cast to scratch an itch, nor should they use lotions or powders near the cast edges, as these can soften the skin or cake up and increase the risk of irritation. Frequent repositioning of the child, every two to four hours, is necessary to prevent pressure sores from forming on the skin beneath the cast.
Mobility and transportation also require specialized solutions, as a child in a spica cast will not fit into a standard car seat or stroller. Hospitals often provide or loan special car seats with wider bases designed to accommodate the cast’s bulk. For moving the child around the home, a padded wagon, a beanbag chair, or a reclining wheelchair may be used, and caregivers must never lift the child by the bar between the legs. Loose-fitting clothing, often one or two sizes larger, is needed to slip over the cast, and some caregivers modify pants or shorts with Velcro closures for easier dressing.