Review Question - QID 4381

Adolescent Blount's disease with significant varus malalignment, a coexisting leg-length discrepancy, and closed growth plates is best treated with a proximal tibia osteotomy with placement of an external fixator.

Adolescent Blount's disease is defined as pathologic genu varum with onset at greater than 10 years of age. Non-operative management is considered for only very mild cases, as the deformity has a tendency to progress and cause medial joint pain. Surgical management consists of either hemiepiphysiodesis or osteotomy. If insufficient growth is remaining to allow for correction via hemiepiphysiodesis, osteotomy is the best option for correction of the deformity. Placement of an external fixator after osteotomy allows for correction of the coexistent leg-length discrepancy.

Gordon et al. review 15 patients with late-onset (mean age 14.9) Blount's that were managed with a comprehensive surgical approach. Proximal tibial osteotomies, +/- distal femur correction with stapling or osteotomy, +/- distal tibia correction with stapling or osteotomy, and application of an Ilizarov frame were used in all patients. They achieved improvement in anatomical and mechanical axes in all patients that was maintained at the 5-year follow-up. They had no wound complications, but had a 100% rate of superficial pin-tract infections.

Wilson et al. review 38 cases where a high tibial osteotomy and placement of an external fixator was used for the treatment of adolescent Blount's disease. Their overall complication rate was 153%, with wound complications being the most common (53%). They also note that 98% of their patients were morbidly obese, which they believe to have increased their complication rate.

Figure A shows a standing AP radiograph of a 15-year-old male with adolescent Blount's disease. Proximal tibia growth plates appear closed and there is significant leg-length difference. Illustration A shows how external fixation following proximal tibia osteotomy can lead to excellent correction of deformity.

Incorrect Answers:
Answer 1: Orthotics are not effective in the treatment of adolescent Blount's disease.
Answer 2: Hemiepiphysiodesis will not be able to provide correction in the setting of closed growth plates.
Answer 3: Hemiepiphysiodesis will not be able to provide correction in the setting of closed growth plates.
Answer 5: Proximal tibial osteotomy with plate fixation will allow for alignment correction, but will be unable to treat the leg-length discrepancy.