IS Case 165: Blount's disease

Chandler Shyu, MD, MPH

Imaging Sciences URMC 2008
Publication Date: 2009-05-21

History

Patient is a 15-year-old male with right knee pain.

Diagnosis

Blount's disease

Discussion

Blount's disease, a.k.a. tibia vara, is an idiopathic disease that affects young children. Varus angulating at the knee can be a normal finding in a child less than one year old. However the abnormal angulation usually resolves once the child starts to walk, so any varus deformity is considered abnormal in patients age 2 and above.

Radiographic findings include localized varus bowing deformity and metaphyseal beaking at the proximal tibia. The metaphyseal diaphyseal angle is greater than 11 degrees.

Theories on pathogenesis of this disease process include altered mechanical stress, ligamentous laxity, early ambulation, and combinations of the factors mentioned above.

References

  1. Wheeless CR III. Wheeless' Textbook of Orthopaedics. http://www.wheelessonline.com/ortho/blounts_disease. March 10, 2008.
  2. Ecklund K, Jaramillo D. Imaging of growth disturbance in children. Radiol Clin North Am. 2001 Jul;39(4):823-41. [PMID: 11549173]

2 images