Correction of Ankle Malalignment in Severe Fibular Hemimelia.

Abstract

Background: Management of ankle joint deformity and instability are challenging issues in congenital fibular hemimelia (FH). This study aims to assess how much the SUPERankle procedure improves ankle alignment and provides durable ankle stability in patients with severe FH.

Methods: Seventeen children aged 53.4±44.1 months with severe form of FH, equinovalgus foot deformation, ankle instability, and tibial curvature (Paley type IIIC), affecting 19 limbs, underwent the SUPERankle procedure. Foot and ankle position was evaluated clinically and radiologically before surgery, immediately after, and at follow-up of 63.0±19.7 months. Mechanical lateral distal tibial angle (mLDTA), tibiocalcaneal angle (mTCA), and tibiocalcaneal distance (mTCD) were measured on the AP radiograms, while the anterior distal tibial angle (mADTA) and lateral tibiocalcaneal angle (mLTCA) were measured on the lateral radiograms. Recurrences, additional procedures, and complications were documented based on medical records. Quality of life was evaluated with Limb Deformity-SRS questionnaire.

Results: On clinical examination, the normal tibia and ankle alignment, along with a plantigrade foot were achieved in all limbs after the first surgery. In 11 limbs (58%) this result was maintained at follow-up. Due to recurrence, additional procedures were necessary to provide durable ankle alignment in 7 limbs (37%), while in 1 limb (5%) the ankle joint remained in equinus at the last follow-up. Significant improvement of radiologic alignment was found in all parameters (preoperative vs. postoperative vs. FU) as follows-mLDTA: 71.4±11.2 versus 88.7±5.6 versus 88.1±2.7 degrees, P =0.0001; mTCA: 41.4±14.9 versus 8.7±8.4 versus 11.6±8.9 degrees, P =0.0001; mTCD: 22.3±7.9 versus 4.0±3.6 versus 7.7±6.5 mm, P =0.0001; mADTA: 99.5±19.4 versus 82.3±4.2 versus 81.5±5.9 degrees, P =0.0002; mLTCA: 116.7±23.9 versus 95.8±11.7 versus 93.5±15.1 degrees, P =0.0002. The mean follow-up LD-SRS score was 4.03.

Conclusion: In children with severe fibular hemimelia, the SUPERankle procedure provided clinically and radiologically fully corrected ankle joint and plantigrade foot, suitable for further lengthening procedure. The 40% rate of deformity recurrence was managed with additional surgical intervention to achieve a good clinical, radiologic, and functional outcome in 95% of children at 5-year follow-up.

Level of evidence: Level IV.