MSK - Perthes Disease Flashcards
Definition
Perthes disease involves disruption of blood flow to the femoral head, causing avascular necrosis of the bone. This affects the epiphysis of the femur, which is the bone distal to the growth plate (physis). The full name is Legg-Calvé-Perthes disease.
Epidemiology
It occurs in children aged 4 – 12 years, mostly between 5 – 8 years, and is more common in boys.
Aetiology
Idiopathic,
- One theory suggests that repeated mechanical stress to the epiphysis may interrupt the blood supply.
Healing process
Over time there is revascularisation or neovascularisation and healing of the femoral head.
Signs and symptoms
The severity of Perthes disease varies between patients.
Perthes disease present with a slow onset of:
- Pain in the hip or groin
- Limp
- Restricted hip movements
- There may be referred pain to the knee
There will be no history of trauma. If the pain is triggered by minor trauma, think about slipped upper femoral epiphysis, particularly in older children.
Diagnosis
- FIRST LINE = X-ray = early changes include widening of joint space, later changes include decreased femoral head size/flattening however this can be normal.
Other investigations that can be helpful in establishing the diagnosis are:
- Blood tests are typically normal, particularly inflammatory markers that are used to exclude other causes
- Technetium bone scan
- MRI scan
Conservative Treatment
Initial management in younger and less severe disease is conservative. The aim of management to maintain a healthy position and alignment in the joint and reduce the risk of damage or deformity to the femoral head. This is with:
- Bed rest
- Traction
- Crutches
- Analgesia
Other treatment
- Physiotherapy = used to retain the range of movement in the muscles and joints without putting excess stress on the bone.
- Regular xrays = used to assess healing.
- Surgery may be used in severe cases, older children or those that are not healing. The aim is to improve the alignment and function of the femoral head and hip
Complications
- Soft and deformed femoral head (MC), leading to early hip osteoarthritis. This leads to an artificial total hip replacement in around 5% of patients.