LAUSR

The proximal ulna has been comprehensively described in the anatomic literature and imaging studies. However, to the best of our knowledge, the anatomy of the proximal ulna in children has not been fully described in the literature. The present study was conducted on 189 children aged between 0 and 12 years (4.7 ± 2.7) by analysis of lateral X-rays of the forearm. Proximal ulna dorsal angulation (PUDA), tip-to-apex (TTA), and total ulnar length (TUL) were measured. The correlation between age and the various X-ray measurements was recorded and then compared with gender differences and adult measurements. Three orthopedic surgeons independently examined the X-ray films and confirmed the reliability of the original observations through intra-group correlation coefficients. There was a strong positive correlation between age and TUL (r = 0.834), and a moderately negative correlation between age and PUDA (r = − 0.405). No significant differences were observed between different genders (p > 0.05). Compared with adults, all measurements were smaller except for PUDA, all such measurements statistically significantly different between children and adults (p < 0.05). Interobserver and intraobserver reliability were “very good” for TUL (0.81–1.00), and “good” for PUDA, TTA, and TTA% (0.61–0.80). Good understanding of the anatomy of the pediatric proximal ulna will help to increase the knowledge base in pediatric orthopedic surgeons allowing them to provide improved treatment of fractures. Restoration of the correct forearm anatomy should result in superior clinical and functional results.