The purpose of this study was to investigate the current epidemiology of DDH using a comprehensive nationwide survey in Japan. A questionnaire was sent to orthopedic surgeons in 1,987 facilities nationwide. A total of 783 (39%) facilities completed and returned the card of DDH. Of these, 79% reported no cases of DDH-related dislocation over the 2-year period, while the remaining facilities reported 1,295 cases.
The characteristics of children diagnosed with DDH-related dislocation were as follows: girls (89%), left side involvement (69%), bilateral involvement (4%), positive family history (27%), first-born (53%), and pelvic position at birth (15%). Seasonal variation showed an increase in DDH incidence among those born in the winter. Overall, 199 cases (15%) were diagnosed at >1 year of age, and these included 36 cases diagnosed very late, at >3 years of age. The majority of the 199 cases of late diagnosis had received earlier routine screening at <1 year of age. The characteristics of the children diagnosed with DDH nationwide were similar to past data from local regions. However, many children were diagnosed late (>1 year of age), particularly in the more populous regions. The findings identify a need for improved early routine screening for DDH in Japan.
Dr. Tadashi Hattori 1980 Graduated from Shinsyu University School of Medicine , Nagano, Japan
Professional career
1987-1998 Nagoya University School of Medicine, Nagoya, Japan
1998-2003 Aichi Prefectural Colony, Central Hospital, Kasugai, Japan
2003-2020 Aichi Children’s Health and Medical Center (ACHMC), Obu, Japan
Society Memberships
Japanese Pediatric Orthopedic Society
Executive-Director (2013~2018), Congress president (2020)
Japanese Society of Orthopedic Ultrasonics
Executive-Director (1995~2016), President (2017~)