Background: Congenital posteromedial bowing of the tibia (PMBT) is a rare deformity with limb length discrepancy (LLD) with or without significant angular deformity. Some patients need only limb length equalization while many patients require additional angular correction. Limb length equalization may be achieved by either limb lengthening, epiphysiodesis or acute shortening of the long leg. Limb lengthening is the preferred treatment option in PMBT patients with significant angular deformity.
Objective: The presented study is to evaluate the results of lengthening with Ilizarov fixator in these patients.
Material and Method: PMBT patients treated with Ilizarov lengthening were retrospectively reviewed. Progression of
angular deformity and LLD were assessed. Residual deformity after Ilizarov lengthening and complications were also evaluated.
Results: Limb lengthening with Ilizarov external fixator was performed in 4 PMBT patients. Mean age at surgery was 3.7
years. Expected LLD (using multiplier method) of tibia ranged from 5.1 to 9.9 cm. Younger patients had more angular deformity than older patients. One patient had pin tract infection requiring Ilizarov removal. Lengthening index varied from 1.2 to 2.1 month/centimeter. LLD after the lengthening was -1.4 to 0.4 cm. Mean progression of LLD was 1.8 mm/year.
Conclusion: Ilizarov lengthening for posteromedial angulation shown good result with average residual LLD 0.4 to 1.4 cm which is not clinically significant.

Keywords: Congenital posteromedial angulation of tibia, Congenital posteromedial bowing of tibia, Leg length discrepancy, Ilizarov