Blount disease

Definition

A rare primary bone dysplasia characterized by disordered endochondral ossification of the medial part of the proximal tibial physis leading to multiplanar deformities of the lower limb. Patients present with bow-legged deformity with bone angulation just below the knee which is mostly bilateral. Severe deformity may result in early degenerative arthritis of the knee. It may occur as an isolated condition or as a part of a syndrome. It mostly occurs in infancy, however adolescence-onset patients have also been reported. Risk factors may include obesity and early walking.