Perthes disease

Question 1

What is Perthes disease?

what age group mainly gets it?

Answer 1

• avascular necrosis of femoral head
• can follow transient synovitis
• 4-8 y/o

Question 2

what is the male to female ratio for Perthes?

what percentage of Perthes is bilateral?

Answer 2

• 5:1 male
• rare in non-caucasians
• 10-15%

Question 3

what is the pathogenesis of perthes?

Answer 3

• avascular necrosis of the nucleus of proximal femoral epiphysis
• results i abnormal growth of epiphysis
• remodelling of regenerated bone

Question 4

how might perthes present?

Answer 4

• pain in the hip or knee causing a limp
• effusion (from synovitis)
• all movements of hip are limited
• antalgic gait
• Trendelenburg gait
• no history of trauma

Question 5

what test can be done on examination to confirm perthes?

Answer 5

• the roll test
• patient lying in supine position
• examiner rolls hip of affected extremity internally and externally invoking guarding or spasm

Question 6

what investigations should you do for perthes?

Answer 6

• FBC and ESR
• X-ray: shows widened joint space
• collapse and deformity of femoral head with new bone formation

Question 7

how should perthes be managed?

what warrants surgery in perthes?

Answer 7

• bracing/ traction
  recovery may take 3 years
• children with skeletal age <6 do well without treatment
• children >6 and who have >50% femoral head necrosis