Simultaneous Biarticular Growth Modulation for Ipsilateral Concomitant Valgus Deformities of the Knee and Ankle: Short-Term Results of a Case Series.

BACKGROUND/

OBJECTIVES

Valgus deformities of the knee and ankle are frequently diagnosed during adolescence. Hemiepiphysiodesis (HED) using the tension-plate technique has become the standard approach for guided growth in both joints. Notably, valgus deformities may simultaneously affect both joints. While substantial data supports monoarticular guided growth, evidence for ipsilateral biarticular growth modulation remains limited. The aim of this case series was to evaluate the feasibility, safety and short-term radiographic outcome of simultaneous ipsilateral biarticular HED for concomitant valgus deformities in the knee and ankle (CKAVD).

METHODS

This retrospective monocentric observational study included 21 legs from 21 consecutive children treated with simultaneous ipsilateral biarticular HED for CKAVD between 2013 and 2022. The initiation and termination of growth modulation were based on clinical (intermalleolar distance, pain in both joints) and radiological parameters. Standing whole-leg coronal plain radiographs were evaluated at the start of modulation and after complete hardware removal, assessing the anatomical femorotibial angle (aFTA), anatomical lateral distal femoral angle (aLDFA), medial proximal tibial angle (MPTA), and lateral distal tibial angle (LDTA).

RESULTS

The mean age at implantation was 11.5 years (SD 1.08); females (n = 7) were younger than males (n = 14, p < 0.05). The mean duration of growth modulation was 14.3 months (SD 4.3). The intermalleolar distance improved by an average of 10 cm (SD 4.4). The aFTA improved by an average of 6.9 degrees (SD 2.6), the aLDFA by 6.7 degrees (SD 2.7), the MPTA by 7.2 degrees (SD 2.3), and the LDTA by 7.1 degrees (SD 3.0). Two-stage hardware removal was required in 6 legs (29%). In one case, a relapse of knee valgus occurred.

CONCLUSIONS

Comprehensive evaluation of all major joints seems to be crucial during the diagnostic workup for coronal plane deformities of the lower extremity. For children with ipsilateral symptomatic CKAVD, simultaneous biarticular HED may be considered as a feasible treatment approach, demonstrating promising short-term outcomes and a low observed complication rate.