What should you know about left Perthes disease?

The femoral head is the rounded top of the thighbone that sits in the hip socket. In Perthes disease, its blood supply is reduced for a time, so the bone can soften, change shape and later heal. The process takes time and is followed with examinations and imaging. The left hip may feel stiff, and a child may limp, avoid running or report pain in the groin, thigh or knee.

The aim of care is to keep the hip moving safely and help the femoral head remain well seated in the socket while it heals. The plan depends on the child's age, hip movement, stage of the condition and shape of the joint. It is different from adult hip osteoarthritis, although altered hip shape can affect the joint much later.

Keep scheduled orthopaedic appointments even when pain improves. Follow restrictions on running, jumping or contact sport, and use crutches or other support if prescribed. Gentle movement within the agreed range helps prevent stiffness; do not force painful stretches or allow a child to return to impact activity without guidance.

[Paediatric Physiotherapy](/treatments/physiotherapy-and-rehabilitation/paediatric-physiotherapy/) can support safe hip movement, muscle control and everyday adaptations. If the hip is not staying well contained or the shape is at risk, the team may discuss surgery such as an [Osteotomy](/treatments/reconstructive-orthopedic-surgery/osteotomy/). Keep a note of limp, pain location, activity tolerance and any change in movement for appointments.

Contact the treating team if limping increases, hip movement becomes more restricted, pain persists at rest or the child stops taking part in ordinary activities. Seek urgent care after a fall with severe pain, inability to stand, fever with a hot painful hip, or sudden marked deterioration. These features can have causes other than Perthes disease and need timely assessment.

Ask what stage the left hip is in, which movements and activities are safe, how often imaging is needed, and what changes would prompt a different treatment. Ask how school, play, sleep and pain relief should be managed, and whether physiotherapy or an operation is being considered.