What should you know about Perthes disease surgery?

Perthes disease affects the developing ball of the hip joint. Treatment decisions depend on the child’s age, hip movement, how much of the ball is involved, and whether the ball remains centred in the socket. Some children are managed with observation, activity changes, pain relief, and guided exercises. Others may need an operation to improve the position of the hip while the bone repairs.

An osteotomy changes the angle or alignment of a bone so the ball sits more securely in the socket. The surgeon may operate on the thigh bone, the pelvis, or both. This is different from replacing the joint. A cast, brace, crutches, or restricted weight-bearing may be needed for a period after surgery, followed by rehabilitation to restore movement and strength.

Before an operation, ask which activities are allowed, how your child will move around safely, and whether school arrangements are needed. Follow the orthopaedic team’s instructions about weight-bearing and wound care. Do not add stretches, sports, or pool activities until the team confirms they are suitable.

Rehabilitation often focuses first on protecting the hip and maintaining safe movement, then on rebuilding strength and walking control. Paediatric physiotherapy can help make exercises age-appropriate. Keep follow-up appointments because X-rays and examinations show whether the hip is staying centred as it heals.

Contact the surgical team promptly if pain is worsening rather than settling, a dressing becomes soaked, the wound develops spreading redness or drainage, or your child develops a fever. Seek urgent help for a cold, pale, blue, or numb foot; severe swelling; new weakness; or pain that is suddenly much stronger.

After recovery, arrange review for a new or worsening limp, reduced hip movement, or pain that returns with ordinary activity. A limp can have many causes and does not by itself confirm Perthes disease or show that surgery has failed.

Ask: Why is surgery recommended now? Which bone will be treated, and how will the operation keep the hip centred? How long might protected weight-bearing last? What pain plan, equipment, and school support will be needed? Which signs should prompt a same-day call, and how will follow-up X-rays guide the next stage?