Which of the following is a characteristic feature of Blount’s disease?
**Core Concept**
Blount's disease is a growth disorder of the tibia, characterized by an abnormal growth of the medial aspect of the proximal tibial epiphysis, leading to a varus deformity of the leg. This condition is often associated with tibial torsion and genu varum, resulting in a bow-legged appearance.
**Why the Correct Answer is Right**
The characteristic feature of Blount's disease is the medial proximal tibial epiphysis growth disturbance. This growth abnormality leads to an increased medial proximal tibial angle (MPTA) and a decreased medial distal tibial angle (MDTA), resulting in a tibial varus deformity. The condition is often bilateral and can lead to significant gait disturbances and limb deformity if left untreated.
**Why Each Wrong Option is Incorrect**
**Option A:** Tibial torsion is a common associated feature of Blount's disease, but it is not the characteristic feature.
**Option B:** Genu varum is a consequence of the growth disturbance in Blount's disease, but it is not the defining characteristic.
**Option C:** Tibial epiphyseal dysplasia is a feature of other growth disorders, but it is not specific to Blount's disease.
**Clinical Pearl / High-Yield Fact**
Blount's disease often presents in infants and toddlers, and early recognition and treatment are crucial to prevent long-term deformity and gait disturbances.
**Correct Answer:** C.