Limb lengthening in congenital posteromedial bow of the tibia

Congenital posteromedial bowing of the tibia (PMBT) is a rare condition affecting one lower limb. The bowing of the tibia usually resolves; however, there is associated limb length discrepancy (LLD), which often persists and can cause functional deficits. Advances in limb lengthening techniques allow this issue to be addressed, often with concomitant angular deformity correction. This study examined eleven patients who have had limb lengthening procedures with mean pre-operative LLD of 3.7 cm (range 1.5–5 cm), mean increase in length was 3.9 cm (range 1.5–5.8 cm), and mean LLD at last follow-up was less than 0.6 cm (range 0–2.0 cm). The main complications were minor or moderate grades, such as pin site infection. Greater LLD was found than previously reported, and we believe that the tertiary referrals were those of a severe form of PMBT. The authors conclude that in view of deformity with discrepancy, in select cases, correction and lengthening would be an option rather than only contralateral epiphysiodesis.