Treatment of severe early-onset Blount’s disease by simultaneous medial hemiplateau elevation and metaphyseal osteotomy using the Ilizarov fixator

Abstract

The purpose of this study was to evaluate the outcome of simultaneous medial tibial plateau (MTP) elevation and metaphyseal osteotomy using Ilizarov fixator in severe early-onset Blount’s disease. Patients and methods: Between 2012 and 2017, we treated 10 cases (14 limbs) of severe early-onset Blount’s disease by double tibial osteotomy procedure using Ilizarov fixator. Their mean age was 10.3 years (9 – 13). All were Langenskiold's stages V /VI with MTP-depression > 30°.Results: The mean follow-up period was 18 months (12 - 32 months). Radiographically; (a) The tibio-femoral angle (TFA) changed from -35° (-25 to -49°), preoperatively to +3.1° (-1 to +9°), postoperatively (P=0.00), and to 0.9 (-5° to + 3°) finally (P=0.06). (b) The medial proximal tibial angle (MPTA) changed from 52° (44 – 63°) preoperatively, to 90° (90 to 95°) postoperatively (P=0.00), and to 87°.8 (83 – 90°) finally (P=0.23). (c) The medial tidial plateau depression angle (MTPDA) changed from 38°(32 – 57) preoperatively, to 6° (0 -8) postoperatively (P=0.00), and to 7° (2 -9°) finally (P=0.21). (d) The mechanical lateral distal femoral angle (mLDFA) was 86°(83 – 88°) and showed no significant change till finally. The outcome according to Schoenecker’s criteria was good in 12 limbs and medium in two. Complications included pin tract infection (10 limbs), temporary foot drop (one limb), and distal osteotomy delayed union (two tibias).Conclusions: This procedure is reliable in treating severe early-onset Blount disease, in terms of joint congruence, limb axes and limb length discrepancy.