Ultrasound Assessment of the Skeletal Development of the Proximal Tibial, Proximal Femoral, and Distal Femoral Epiphyses in Premature and Mature Newborns

We evaluated postnatal skeletal development of the proximal femoral epiphysis, distal femoral epiphysis (DFE) and proximal tibial epiphysis (PTE) in 178 premature and mature newborns, between 25 and 47 wk of biological age, using high-resolution B-mode musculoskeletal ultrasound. Approximate age-related values were determined based on the ossification center size and epiphyseal cartilage thickness. The earliest onsets of visible mineralization were at 30 wk of maturity in the DFE, 31 wk in the PTE and 43 wk in the proximal femoral epiphysis. In preterm and term neonates, significant correlations were observed for transverse and longitudinal length of the DFE and PTE with biological age (R² = 0.35-0.50, p < 0.01). No significant age-dependent increases or decreases in cartilage thickness were seen between the ossification centers and cartilage surface in the DFE and PTE. High-resolution B-mode musculoskeletal ultrasound is an excellent tool for assessing skeletal development in premature and mature newborns.