Purpose: Side-to-side differences in bone age may exist due to somatic mosaicism in congenital hemihyperplasia or hemihypoplasia. We aimed to assess bone age differences between limbs in these conditions. Methods: We retrospectively identified 118 children who underwent molecular testing for congenital hemihyperplasia or hemihypoplasia. Diagnoses included Beckwith-Wiedemann syndrome (BWS) ( n = 34), Silver-Russell syndrome ( n = 14), PIK3CA-related overgrowth spectrum (n = 14), and idiopathic isolated hemihyperplasia or hemihypoplasia ( n = 56). Hand and knee bone ages were compared between the right and left limbs and between the longer and shorter limbs. Results: In the overall cohort or each disease group, there was no difference in hand or knee bone age between the right and left limbs. However, the hand bone age of the longer limb was 1.2 ± 2.6 months older than that of the shorter limb ( p = 0.005). In subgroup analysis, patients with BWS showed older knee (7.1 ± 9.9 months, p = 0.031) and hand (3.2 ± 2.5 months, p = 0.026) bone ages in the longer limb compared to the shorter limb. No significant differences were observed in the other disease groups. Conclusions: Pediatric patients with congenital hemihyperplasia or hemihypoplasia generally show minimal bone age differences between limbs. However, in BWS, the longer limb may have a bone age several months older than the shorter limb. Significance of study: Surgeons need to consider potential side-to-side differences in bone age when estimating remaining growth and determining the timing for epiphysiodesis in these patients. Level of Evidence: III—Study of nonconsecutive patients
Lee et al. (Fri,) studied this question.