Angular Deformity after Temporary Epiphysiodesis for Leg Length Discrepancy

Abstract

Aims: Temporary epiphysiodesis with tension band plating is used to manage leg length discrepancy. Temporary epiphysiodesis may offer surgical timing benefits over permanent drill epiphysiodesis, but a potential complication is secondary angular deformity. We aimed to describe angular deformity and associated factors after temporary epiphysiodesis. Materials and Methods: In this retrospective review of patients who underwent temporary epiphysiodesis of the distal femur and/or proximal tibia, mechanical axis deviation (MAD) was measured on preoperative and last follow-up radiographs. Changes in MAD and angular deformity were analyzed using nonparametric statistics. Angular deformity was defined as MAD >10 mm from neutral. Results: In our cohort of 12 patients (age at surgery 11.3 ± 2.0 years; postoperative follow-up 2.0 ± 0.9 years), the mean magnitude of MAD change was 14 ± 10 mm. Of five femoral only procedures, four limbs (80%) had lateral (valgus) direction of MAD change, while one had 1 mm varus change. Of two tibial only procedures, both had lateral direction of MAD change. Of five combined femoral and tibial procedures, one limb (20%) had no MAD change, and four limbs (80%) had medial (varus) MAD change. At the last follow-up, 50% (6/12) of limbs had MAD >10 mm from neutral, which they did not have before surgery. Conclusions: For patients with limb length discrepancy, temporary epiphysiodesis with tension band plating may increase the potential for angular deformity. This finding should be considered when this procedure is planned for patients close to skeletal maturity.