TREATMENT OF ADOLESCENT BLOUNT DISEASE BY ASYMMETRIC PHYSEAL DISTRACTION

An alternative treatment is presented for late-onset Blount disease in a 14-year-old boy. The technique consists of asymmetric physeal distr action of the proximal tibial growth plate by using a modified Wagner fixator-distractor device that allows progressive angular correction. The patient had a 23 degrees varus deviation of the left tibia, and no physeal bone bridges were detected. Once the fixator was assembled, d istraction started 24 h after surgery at a rate of 1.5 mm/day (2 x 0.7 5). Complete correction was achieved in 25 days. No osteotomy of the f ibula was required. The Wagner device was removed in the outpatient cl inic 10 weeks postoperatively. After a 4-year follow-up, there was no loss of correction, showing a satisfactory alignment of the operated-o n lower extremity. As compared with acute conventional osteotomies, as ymmetric physeal distraction entails several advantages for treatment of Blount disease such as less invasive surgery, progressive and adjus table correction taking place at the apex of the deformity, and the po ssibility of bone lengthening if needed. Furthermore, physeal distract ion does not require a second surgical step for bone-graft harvesting or for removal of the internal fixation.