Blount Disease

A 16-year-old African American boy complained of exertional pain below his left knee that severely limited his ability to participate in sports. The patient had had bilateral bowed legs until his early school years, when the right knee straightened. For the past year, exertional pain had been present below the left knee in the epiphyseal area.

Tibia vara, or Blount disease, is responsible for the bowing of the patient's left lower leg. The radiographs reveal beaking of the metaphysis and calcification and widening of the proximal tibial epiphyseal plate medially, which has produced a varus deformity at the knee.

Drs Robert P. Blereau, MD and Timothy Haley of Morgan City, La, explain that Blount disease causes bowing at the proximal tibia that affects only the proximal tibial epiphysis. The disorder is found primarily in obese or large black children and adolescents who begin walking early, which creates excessive force on the medial physis of the proximal tibia and inhibits the normal growth of this segment. The lateral physis continues to grow normally, thereby producing the bowing at the knee. The bowing may be unilateral or bilateral.

Refer patients with Blount disease for an orthopedic evaluation. Treatment of tibia vara depends on the age of the patient and stage of the disease. Bracing and surgery may be appropriate for younger children; adolescents usually require operative intervention.

This patient had osteotomies of the tibia and fibula with internal fixation. Results of the surgery were good.