Procedures and Spica Casting

While many cases of Developmental Dysplasia of the Hip (DDH) are resolved with a harness, some children require a procedure to get the hip into the correct position. This may be evaluated if bracing was unsuccessful, if the child was diagnosed later in infancy, or if the hip is completely dislocated and cannot be gently reduced ^[1][2]. Note that age alone (such as a diagnosis after 6 months) does not automatically dictate surgery, and the team will choose among observation, bracing, or procedures based on the specific hip. The goal remains the same: ensuring the “ball” of the hip is seated well within the “socket” so they can develop normally ^[3].

Closed Reduction and Spica Casting

For infants between 6 and 18 months, doctors often evaluate for a closed reduction ^[4]. “Closed” means the procedure is done under anesthesia without making a surgical incision to open the joint.

While the child is asleep, the surgeon gently moves the baby’s hip into the socket. They often use an arthrogram—a special X-ray using injected dye—to see the soft cartilage and ensure the ball is sitting deep enough in the socket ^[5][6].

Once the hip is in place, a hip spica cast is applied. This hard cast covers the baby from the chest down to one or both ankles, holding the hips in a fixed position for approximately 3 to 4 months ^[3][7]. After the cast is applied, an imaging scan—such as an X-ray, fluoroscopy, or MRI, depending on the center’s specific protocols—is used to confirm that the hip stayed securely in the socket before the baby goes home ^[8][9].

Open Reduction

An open reduction is a more involved surgery where the surgeon makes an incision to clear away obstacles that are preventing the hip from seating correctly ^[2]. These obstacles might include tight tendons, fatty tissue (called pulvinar), or a folded joint capsule ^[10].

Open reduction is generally needed if:

• A closed reduction was attempted but the hip was not stable ^[11].
• The child is older (typically over 18 months) ^[1].
• Physical barriers inside the joint are blocking the ball from entering the socket ^[10].

Reshaping the Bone (Osteotomies)

In older children (often 18 months to 3 years or older), simply putting the ball back in the socket may not be enough because the bones have already begun to grow in an abnormal shape ^[1][12]. In these cases, the surgeon may perform an osteotomy—purposefully cutting and reshaping the bone.

• Pelvic Osteotomy: The surgeon reshapes the “socket” (acetabulum) to make it deeper and provide better coverage for the ball ^[13].
• Femoral Osteotomy: The surgeon adjusts the angle of the thigh bone (femur) or shortens it slightly to reduce pressure on the joint, especially in “high” dislocations where the bone has been pulled upward by tight muscles ^[14][15].

Risks and Complications: AVN

The most serious potential complication of DDH procedures is Avascular Necrosis (AVN) ^[16]. This occurs when the blood supply to the “ball” of the hip is interrupted. If the blood supply is cut off for too long, the bone tissue can die, leading to permanent hip damage and early arthritis ^[17][18].

AVN risk is multifactorial and can relate to age, severity, vascular anatomy, prior treatment, and positioning. However, excessive pressure on the joint or an extreme, over-stretched position (too much “abduction”) in the cast are recognized contributors ^[16][9]. To prevent this, modern surgeons use gentle techniques and avoid forcing the legs into wide-open positions ^[19]. Your medical team will monitor your child with X-rays for at least a year after the procedure to look for any signs of AVN ^[9].

Life in a Spica Cast

Caring for a child in a spica cast requires significant lifestyle changes. You will need center-specific instructions for:

• Specialized Seating: Standard car seats usually do not fit a child in a spica cast; specialized, spica-compatible restraints must be obtained and properly fitted before discharge.
• Diapering Techniques: You will likely use a “double-diapering” method to keep the cast clean and dry.
• Skin Care: Checking the edges of the cast daily for redness or irritation is essential.

WHEN TO CALL YOUR CARE TEAM: Urgent Spica Cast Issues

While recovering at home, contact your surgical team urgently (or seek emergency help) if you notice:

• Toes that are blue, pale, cold, very swollen, numb, or difficult for the child to move.
• The child is in worsening pain or is completely inconsolable.
• The cast becomes excessively tight, extremely loose, cracked, or wet/soiled inside.
• Foul odor, unexplained fever, or drainage from the cast.

While the surgery and casting phase is intense, it is a temporary stage designed to provide your child with a stable, functional hip.