Hello and welcome to the Zero to Finals podcast. My name is Tom and in this episode I'm going to be talking to you about Perthies disease.

You can find written notes on this topic at zero definals.com slash perthes or in the orthopedic section of the Zero Definals Pediatrics book.

So let's get straight into it.

Perthi's disease involves disruption of blood flow to the femoral head in the hip,

causing avascular necrosis of the bone.

This affects the epiphysis of the femur,

which is the bone distal to the growth plate, which is called the physis.

The full name is leg calf perthes disease.

It occurs in children aged 4 to 12 years, mostly between 5 and 8 years of age, and is more common in boys.

It's described as idiopathic, meaning there's no clear cause or trigger for the

avascular necrosis. One theory suggests that repeat mechanical stress to the epiphysis may

disrupt the blood supply. Over time, there is revascularization or neovascularization and healing

of the femoral head.

There is remodeling of the bone as it heals.

The main complication is a soft and deformed femoral head

leading to early hip osteoarthritis.

This leads to an artificial total hip replacement in around 5% of patients.

Let's talk about the presentation.

Perthi's disease presents with a slow onset of pain in the hip or groin,

limp, restricted hip movements, and there may be referred pain to the knee.

There should be no history of trauma to the joint.

If the pain was triggered by minor trauma,

...