[Relationship between time of ossification center appearance and hip joint development stage using Graf's method]

The aim of this paper was to relate time of the ossification center appearance and development stage according to Graf. Retrospective analysis included 4546 sonograms in children from 1 to 6 months of age and 1252 sonograms in 313 healthy newborns. An earlier appearance of the ossification center was found in females (7 weeks against 10 weeks of life in males). Statistically significant relationship was found between the delay in the ossification center appearance time and hip dysplasia. The delay exceeding 6 months is suggestive of serious pathology and complications in later stages of hip development.