Paediatrics

Perthes Disease

Perthes disease is childhood osteonecrosis of the femoral head caused by interrupted blood supply; the vulnerable head can deform during fragmentation, so preserving hip movement and containment during growth is central to care.

In a nutshell

Perthes disease is childhood osteonecrosis of the femoral head, usually presenting at around 4 to 10 years with a gradual limp, groin/thigh/knee pain and reduced hip abduction or internal rotation. Early radiographs may be normal. Refer to paediatric orthopaedics for serial imaging, movement-preserving treatment and age- and severity-specific containment decisions; fever or inability to weight-bear requires an alternative urgent pathway.

Classic presentation

A well 6-year-old boy develops a persistent limp and intermittent knee pain; hip examination shows reduced abduction and internal rotation.

Key points

The mechanism is interrupted femoral-head blood supply followed by necrosis, fragmentation and remodelling.
Pain may be referred to the knee; examine the hip in every unexplained limp.
AP pelvis and lateral hip radiographs are first-line specialist imaging, but early films can be normal.
Preserve range of movement and containment with physiotherapy, activity modification and specialist follow-up.
Bracing, casting or surgery is selected by age, stage, movement, containment and femoral-head involvement.
Fever, acute severe pain or inability to weight-bear is not typical and requires urgent reassessment.

First-line investigation

Bilateral hip/pelvic radiographs with a careful range-of-motion examination; use specialist MRI or further assessment if suspicion persists despite normal films.

Management

Confirm and refer

Refer the characteristic limp or restricted hip movement for paediatric orthopaedic assessment and stage-specific imaging.^1,2
Redirect fever, severe acute pain, inability to weight-bear or constitutional symptoms to urgent infection or malignancy assessment.^3,4

Protect movement

Use physiotherapy, activity modification, equipment and current BNF-based analgesia to preserve movement and function.^2,5

Monitor remodelling

Use serial clinical and radiographic review; the specialist team decides when containment treatment or surgery is needed.^1,2

Exam traps

An early normal radiograph does not exclude Perthes disease when the limp and examination remain concerning.
Knee pain can be referred from the hip.
Not every child needs surgery; management is individualised by age, stage and containment.
Fever and inability to weight-bear require consideration of septic arthritis or osteomyelitis.

Illustrations

Perthes disease on pelvic radiographyAP pelvic radiograph showing unilateral sclerosis, fragmentation and flattening of the capital femoral epiphysis in Legg-Calvé-Perthes disease; retain source attribution while image-quality remediation remains separate.J. Lengerke, Wikimedia Commons · Public domain

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.