You are here

Blount’s Disease

synonyms: Genu Varum, Genu Varus, infantile Blounts disease, adolescent Blounts disease

Blount’s Disease ICD-9

Blount’s Disease Etiology / Epidemiology / Natural History

  • Infantile Blounts may develop from extreme physiologic varus which progresses due to growth disturbance in the posterior medial tibial physis.
  • African American > whites.
  • Natural history unknown, up to 50% of patients may improve with time.

Blount’s Disease Anatomy

Blount’s Disease Clinical Evaluation

  • Typically large for age and early walkers.

Blount’s Disease Xray / Diagnositc Tests

  • A/P and lateral Knee, A/P and lateral tibia, long-leg views. Demonstrate medial metaphyseal sloping and epiphyseal fragmentation.

Blount’s Disease Classification / Treatment

  • Physiologic bowing is common in children who are less than 3 years old whereas Blount disease is reported to be less than 1% at this age. Corrective bracing is initiated for presumed early Blount disease only if the metaphyseal-diaphyseal angle is more than 16 degrees. If the angle is less than 9 degrees the patient is observed. Between 9 and 16 degrees, bracing is considered only if there is instability on walking. The patient is then evaluated on 4 month intervals. (Raney EM, JPO 1998;18:670).
  • Infantile Blounts = onset prior to 3y/o.  Lanenskiold Classification(1-6).  Metaphyseal diaphyseal angle (of Drennan) >13 degrees,  Rx=KAFO stages I-IV, Stages V-VI(have metaphyseal bar) osteotomy over correcting to valgus.. (Raney J Pediatr Orthop 18:670;1998)  Xray=orthogram with patellas facing forward.--metaphyseal beaking.
  • Adolescent Blounts, usually overweight, black, RX=lateral hemiepiphysiodesis vs proximal tibial osteotomy

Blount’s Disease Associated Injuries / Differential Diagnosis

Blount’s Disease Complications

Blount’s Disease Follow-up Care

Blount’s Disease Review References

  • Feldman MD, Schoenecker PL; Use of metaphyseal-diaphyseal angle in the evaluation of bowed legs.  JBJS 1993;75A:1602-1609.

Disclaimer

The information on this website is intended for orthopaedic surgeons.  It is not intended for the general public. The information on this website may not be complete or accurate.  The eORIF website is not an authoritative reference for orthopaedic surgery or medicine and does not represent the "standard of care".  While the information on this site is about health care issues and sports medicine, it is not medical advice. People seeking specific medical advice or assistance should contact a board certified physician.  See Site Terms / Full Disclaimer