Perthes Disease

Question 1

What is another term for Perthes disease?

Answer 1

Legg-Calve-Perthes Disease

Question 2

What is Perthes disease?

Answer 2

It is defined as a condition in which there is disruption of blood flow to the proximal femoral epiphysis, resulting in idiopathic avascular necrosis of the bone

Question 3

What four risk factors are associated with Perthes disease?

Answer 3

Young Age, 4 – 10 Years Old

Male Gender

White Race

Family History

Question 4

What are the five clinical features of Perthes disease?

Answer 4

Hip Pain

Hip Stiffness

Limping

Antalgic Gait

Leg Length Discrepancy

Question 5

Describe the hip stiffness associated with Perthes disease

Answer 5

There is a loss of internal rotation and abduction

Question 6

What three investigations are used to diagnose Perthes disease?

Answer 6

Pelvic X-Ray

MRI Scans

Isotope Bone Scans

Question 7

What is the first line investigation used to diagnose Perthes disease?

Answer 7

Pelvic X-Ray

Question 8

What are the seven features of Perthes disease on pelvic x-ray scans?

Answer 8

Asymmetrical Femoral Epiphyseal Size

Increased Femoral Head Epiphysis Density

Widened Joint Space

Coxa Plana

Coxa Magna

Sagging Rope Sign

Crescent’s Sign

Question 9

What is coxa plana?

Answer 9

It is defined as femoral head widening and flattening

Question 10

What is coxa magna?

Answer 10

It is defined as proximal femoral neck deformity

Question 11

What is the sagging rope sign?

Answer 11

It is defined as a thin sclerotic line running across the femoral neck

Question 12

What is the Crescent’s sign?

Answer 12

It is defined as a curvilinear lucent subchondral line caused by a subchondral fracture

Question 13

What is important to note about the use of pelvic x-rays used to diagnsoe Perthes disease?

Answer 13

In the initial stages of disease, it may present with a normal pelvic x-ray

Question 14

When are MRI scans used to diagnose Perthes disease?

Answer 14

They are used to confirm a diagnosis of Perthes disease in cases where clinical features are positive, however x-ray scans are negative

Question 15

What is the feature of Perthes disease on MRI scans?

Answer 15

Femoral head deformity

Question 16

When are isotope bone scans used to diagnose Perthes disease?

Answer 16

They are used to confirm a diagnosis of Perthes disease in cases where clinical features are positive, however x-ray scans are negative

Question 17

What is the feature of Perthes disease on isotope bone scans? Explain

Answer 17

In early disease, there is reduced femoral head uptake – representing the reduced blood supply of osteonecrosis

In late disease, there may be increased femoral head uptake – representing bone repair

Question 18

When is conservative management used to treat Perthes disease?

Answer 18

It is used to treat mild disease and those less than 6 years old

Question 19

What is the aim of conservative management of Perthes disease?

Answer 19

It is to maintain a healthy position and alignment of the hip joint, in order to reduce risk of damage/deformity to the femoral head

Question 20

What are the four conservative management options of Perthes disease?

Answer 20

Observation

Bed Rest

Simple Analgesia

Physiotherapy

Question 21

When is surgical management used to treat Perthes disease?

Answer 21

It is used to treat severe disease and those greater than 7 years old

Question 22

What is the surgical management option of Perthes disease?

Answer 22

Osteotomy

Question 23

What is osteotomy?

Answer 23

It involves cutting and reshaping the femoral head, in order to improve the alignment and function of the hip joint

Question 24

What are the two complications associated with Perthes disease?

Answer 24

Osteoarthritis

Acetabular Dysplasia