Perthes disease Flashcards
What is Perthes disease?
Perthes disease is idiopathic avascular necrosis of the hip, in which the blood supply becomes interrupted
What age and gender are most likely to get Perthes disease?
Ages 4-9
Males (5:1)
What are some risk factors of Perthes disease?
Family history
Low birth weight
Passive smoke
Asian, Inuit or Central European descent
Describe the pathophysiology of Perthes disease
In Perthes disease, the femoral head transiently loses its blood supply, resulting in necrosis with subsequent abnormal growth
The femoral head may also fracture and collapse
Subsequent remodelling does occur due to the age of disease, however, the shape of the femoral head and congruence of the joint is determined by age of onset, with older children faring worse
An incongruent joint will lead to early onset of arthritis and in severe cases, may require hip replacement in adolescence or early adulthood
How will most patients present with perthes disease?
Most children will present with pain and a limp
What are some possible causes of bilateral Perthes disease?
Underlying skeletal dysplasia
Thrombophilia
What are some clinical signs of Perthes disease?
Loss of internal rotation
Loss of abduction
Positive Trandellenburg test (Gluteal weakness)
What investigations are required in Perthes disease?
X-ray findings may be normal, so MRI or bone scan are usually indicated
How is Perthes disease usually treated?
The blood supply often comes back but necrosis cannot be undone, and regrowth of tissue can lead to deformities in the hip
There is no usual specific treatment, other than regular observation and avoidance of physical activity
In some cases, the femoral head becomes aspherical, flattened and widened, with some trochanteric overgrowth in healing
Treatment aims usually to prevent this abnormal growth and in cases where it does occur, osteotomy of the femur or acetabulum may be indicated
