A spica cast is a large orthopedic device used to immobilize the hips and legs of infants and young children. This cast typically extends from the chest or waist down to one or both legs, securing the pelvis and thigh bones in a specific position. The cast holds the child’s hip joint or a broken bone perfectly still to facilitate healing. The total treatment time is highly individualized based on the patient’s medical condition and healing rate.
What is a Spica Cast Used For?
The primary purpose of a spica cast is to stabilize the hip or thigh to facilitate the healing of serious musculoskeletal conditions in pediatric patients. The two most frequent conditions necessitating this treatment are Developmental Dysplasia of the Hip (DDH) and a fracture of the femur. For DDH, the cast holds the ball of the hip joint securely within its socket, encouraging proper development and preventing dislocation after a reduction procedure.
For a femur fracture, the cast acts as a rigid external splint, maintaining the bone fragments in alignment so they can knit back together correctly. The exact configuration varies depending on the injury location. A single hip spica covers the trunk and one leg, a one-and-a-half hip spica covers the entire injured leg and the opposite leg only to the knee, and a double hip spica includes both legs fully.
Factors Determining Treatment Duration
The time a child remains in a spica cast depends significantly on the underlying medical issue, the child’s age, and the healing response. For a femur fracture in a young child, the duration is often shorter, typically ranging from four to eight weeks until sufficient bone healing is achieved. Fracture healing is generally more predictable than the complex joint remodeling required for hip correction.
Treating DDH often requires longer time to ensure the hip joint capsule and surrounding soft tissues tighten adequately to keep the hip permanently in place. Following a closed reduction for DDH, a child may need the cast for 12 to 16 weeks. The cast may be changed under anesthesia at six-week intervals to check progress. After a more involved open reduction surgery, the duration in the spica cast may be between six and twelve weeks.
Cast removal is based on objective medical evidence of successful healing, not a predetermined date. Specialists use regular imaging, such as X-rays or arthrograms (which use dye to visualize the joint), to confirm the bone has fully healed or the hip joint has achieved a stable, centered position. The child’s age is also a factor, as infants heal and remodel bones faster than older toddlers.
Managing Daily Life in a Spica Cast
Adapting to the spica cast requires substantial adjustments to the child’s daily routine, especially concerning hygiene and mobility.
Skin Care and Hygiene
Meticulous skin care is required to prevent irritation and pressure sores, particularly around the cast edges. Parents must conduct frequent checks using a flashlight to look inside the cast for redness or pressure marks. Never insert objects, powders, or lotions into the cast.
Diapering and Bathing
For diapering, “double diapering” is used: a smaller diaper is tucked inside the cast opening and a larger diaper is placed over the outside to contain waste and keep the cast dry. Since the cast cannot be submerged, bathing must be done via a sponge bath. Any damp areas of the cast liner should be dried immediately with a hairdryer set to a cool setting. Positioning the child with their head slightly elevated uses gravity to help direct waste away from the cast’s padding.
Mobility and Feeding
Mobility is restricted, necessitating frequent changes in position—at least every two to four hours while the child is awake—to alleviate pressure on the skin. Feeding is best accomplished with the child positioned upright to aid digestion and prevent food crumbs from falling into the cast. Safe transportation requires a specialized car seat designed to accommodate the wide angle of the cast. Caregivers must lift the child by supporting the trunk and legs, never by the crossbar between the legs. Due to decreased activity, a diet rich in fiber and fluids is encouraged to minimize constipation.
Cast Removal and Post-Treatment Care
The process of removing a spica cast is typically performed in a clinic or operating room, often under sedation or general anesthesia, to ensure the child remains calm and still. A specialized electric cast saw is used to cut through the layers. While the saw is noisy, it is designed to vibrate and cut the rigid material without harming the underlying skin. Once the cast is removed, the skin underneath will appear dry, flaky, and pale due to the long period of coverage.
Immediate post-cast care involves gently washing the skin with mild soap and water and applying a moisturizing cream, avoiding aggressive scrubbing. The child’s muscles, particularly those in the thigh, will show signs of atrophy from the long period of immobilization. A period of rehabilitation is necessary, and most children begin physical therapy to help them regain strength, flexibility, and normal range of motion.
After removal, the child commonly transitions into a lighter orthotic, such as a removable hip abduction brace or splint, for several more weeks. This brace gradually weans the hip joint from the cast, providing continued support while allowing for increased movement. The medical team provides a specific schedule for brace use to ensure the long-term stability of the corrected hip or healed fracture.