Osteochondritides (incl. Perthe’s, Osgood-Schlatter)

Question 1

Define Perthe’s disease.

Answer 1

Perthes’ disease is a degenerative condition affecting the hip joints of children, typically between the ages of 4-8 years.

BMJ: It is a self-limiting disease of the femoral head comprising of necrosis, collapse, repair, and re-modelling that presents in the first decade of life

Question 2

What is the pathophysiology of Perthe’s disease?

Answer 2

It is due to avascular necrosis of the femoral head, specifically the femoral epiphysis. Impaired blood supply to the femoral head causes bone infarction.

It is bilateral in 10% of cases

Question 3

Who is mostly affected by Perthe’s disease?

Answer 3

<10 yr olds

5x more common in boys

Question 4

What are the main features of Perthe’s disease?

Answer 4

• hip pain: develops progressively over a few weeks
• limp
• stiffness and reduced range of hip movement

x-ray: early changes include widening of joint space, later changes include decreased femoral head size/flattening

Question 5

What investigations are used in the diagnosis of Perthe’s disease?

Answer 5

1. plain x-ray
2. technetium bone scan or magnetic resonance imaging if normal x-ray and symptoms persist

Question 6

Name 2 complications of Perthe’s disease.

Answer 6

1. osteoarthritis
2. premature fusion of the growth plates

Question 7

What staging is used for Perthe’s disease?

Answer 7

Question 8

How do you manage Perthe’s disease?

Answer 8

• To keep the femoral head within the acetabulum: cast, braces
• <6 years: observation
• >6 years : surgical management with moderate results
• Operate on severe deformities

Question 9

How do you manage acute episodes of Perthe’s disease?

Answer 9

• Conservatively with NSAIDs such as ibuprofen, or paracetamol
• Rest
• Abduction plasters (if necessary)

Question 10

What is the prognosis with Perthe’s disease?

Answer 10

Most cases will resolve with conservative management. Early diagnosis improves outcomes.

Question 11

What might you find on examination in Perthe’s disease?

Answer 11

• Antalgic gait in acute episodes
• Trendelenburg’s test may be positive due to gluteal muscle wasting
• Apparent limb shortening
• Reduced range of motion

Question 12

What are the 4 stages of Perthe’s disease?

Answer 12

1. Ischaemia
2. Resorption, fragmentation, re-vascularisation, and repair
3. Re-ossification and resolution
4. Remodelling

Question 13

A 6-year-old boy presents with pain in the hip it is present on activity and has been worsening over the past few weeks. There is no history of trauma. He was born by normal vaginal delivery at 38 weeks gestation On examination he has an antalgic gait and limitation of active and passive movement of the hip joint in all directions. C-reactive protein is mildly elevated at 10 but the white cell count is normal. What is the most likely diagnosis?

Answer 13

Perthe’s disease - X-ray may show flattening of the femoral head or fragmentation in more advanced cases.

Question 14

Define Osgood-Schlatter disease.

Answer 14

Paediatric overuse syndrome causing traction apophysitis of the tibial tubercle

Question 15

What are the risk factor for Osgood-Schlatter disease?

Answer 15

• male
• athletic - sports with repeated forceful knee extension
• adolescent
• history of OSD

Other: proximal/broader tibial attachment of the tibia, increased external tibial torsion, patella alta (high position of patella)

Question 16

What is the management of OSD?

Answer 16

Bed rest - OSD is self limiting

Other:

• Ice pack or compressive bandage can be applied if swelling
• NSAIDs early
• Physiotherapy after acute epidose to strengthen quadriceps and hamstrings

Question 17

What is the prognosis of OSD? What complications can occur?

Answer 17

Prognosis: 90% is self-limiting with excellent prognosis.

Complications: Bony overgrowth of the tibial tubercle/persistence of a bony ossicle into adulthood can impinge on the patellar tendon, causing pain and limiting activity. This can be fixed surgically with excision of the ossicle and/or osteoplasty of the tibial tubercle, with excellent long-term outcomes.

Question 18

What is the aetiology of OSD?

Answer 18

Traumatic theory: micro-avulsion at the insertion of the patellar tendon caused by repeated traction injury

Circulation theory: disturbance in the circulation of the apophysis due to rapid bone growth during adolescence, leading to the inability of the apophysis to withstand traction forces from the patellar tendon.

Question 19

What is the epidemiology of OSD?

Answer 19

• More common in athletic children
• Occurs at 8-12 years in girls and 12-15 years in boys
• Males > females
• Bilateral in 20-30%

Question 20

Describe the symptoms of OSD.

Answer 20

• Pain at the tibial tubercle
• Pain worsened by activity (for example, sport)
• Pain relieved by rest, ice, and anti-inflammatory medicines.

Question 21

What are the findings on examination in OSD?

Answer 21

• Localised swelling
• • Localised tenderness
• Localised warmth
• Prominence of the tibial tubercle
• Pain at the tibial tubercle with resisted knee extension.

Question 22

How is OSD diagnosed?

Answer 22

Clinically

Question 23

When should you request a plain X ray for OSD?

Answer 23

If the pain is unilateral, severe, or persistent, and if there is any history of trauma.

Question 24

When should an MRI be requested in OSD?

Answer 24

If malignancy or infection is suspected instead

Question 25

What is ‘irritable hip’?

Answer 25

Transient synovitis - cause of acute hip pain in children aged 2-12 years often accompanied by viral infection

Question 26

How does transient synovitis present?

Answer 26

• Acute onset pain in the hip or a limp.
• No pain at rest
• Decreased range of movement including internal rotation
• Pain may be referred to knee
• Mild fever or afebrile

Question 27

What is a differential diagnosis for irritable hip?

Answer 27

Early septic arthritis of the hip joint - must do joint aspiration and blood cultures if this is suspected

Question 28

Which condition is irritable hip sometimes associated with?

Answer 28

May precede the development of Perthe’s disease

Question 29

What is the management of irritable hip?

Answer 29

Bed rest and rarely skin traction

Usually resolves within a few days

Question 30

Compare and contrast irritable hip with septic arthritis.

Answer 30