Legg-Calve-Perthes Disease

Question 1

What is Legg-Calve-Perthes disease?

Answer 1

Spontaneous idiopathic avascular necrosis of the proximal femoral epiphysis in children
MC 4-8yo
MC males; 5:1 ratio
a/w ADHD in 33% of cases
Bone age delayed in 89% of pts

Question 2

How often is Legg-Calve-Perthes disease bilateral?

Answer 2

12%

Question 3

What are risk factors for Legg-Calve-Perthes disease?

Answer 3

1) positive family history
2) low birth weight
3) abnormal birth presentation
4) children exposed to second hand smoke
5) Asian, Inuit, and Central European decent

Question 4

What is the classification of Legg-Calve-Perthes disease?

Answer 4

Lateral Pillar (Herring):
Group A- lateral pillar maintains full height, no density changes
Group B- maintains >50% height; poor outcomes in >6yo
B/C border- lateral pillar is narrowed (2-3mm) or poorly ossified with approximately 50% height
Group C- less than 50% of lateral pillar height is maintained

Question 5

What are the stages of Legg-Calve-Perthes disease?

Answer 5

Initial- Infarction produces a smaller, sclerotic epiphysis with medial joint space widening
Fragmentation- Femoral head appears to fragment or dissolve; Result of a revascularization process and bone resorption producing collapse and subsequent increased density
Reossification- Ossific nucleus undergoes reossification as new bone appears as necrotic bone is resorbed
Healing or remodeling- Femoral head remodels until skeletal maturity

Question 6

What are the treatment(s) for Legg-Calve-Perthes disease?

Answer 6

Herring A- PT, NSAIDs, observation

Herring B/C- Pelvis or femoral osteotomy

Question 7

What are five “at-risk” signs seen in Legg-Calve-Perthes disease that signify more severe disease course?

Answer 7

1) Lateral subluxation of femoral head
2) Horizontal physis
3) Metaphyseal cysts
4) Calcification lateral to epiphysis
5) Radiolucency in shape of V on lateral side of epiphysis (Gage sign)

Question 8

What is the Stulberg classification of Legg-Calve-Perthes disease?

Answer 8

Risk of OA with radiographic appearance of head at maturity:
I- normal hip joint (0%)
II- Spherical enlarged head, short neck, steep acetabulum (16%)
III- Nonspherical head (i.e. ovoid, mushroom, umbrella) (58%)
IV- Flat head (75%)
V- Flat head with incongruent joint (78%)

Question 9

What are treatment options by age of onset for Legg-Calve-Perthes disease

Answer 9

1) Onset before age 8 can be non-op

2) after age 8, pelvic or femoral osteotomy to provide containment

Question 10

What are the typical deformities seen with Legg-Calve-Perthes disease?

Answer 10

1) Enlarged aspherical femoral head (coxa magna)
2) Proximal femoral neck is shortened
3) Greater trochanter becomes more prominent