Seasonal variation of surgically treated distal radius fracture in Japan using inpatient database: cross-sectional study.

Introduction: The purpose of this study was to clarify the relationship between seasonal variation and distal radius fractures using diagnosis procedure combination data in Japan.

Materials and methods: The participants were hospitalized patients who underwent surgical treatment for distal radius fracture as the primary injury at hospitals that introduced the diagnosis procedure combination system between April 2011 and March 2016. We obtained a summary table of the month of admission, region of residence, age at admission, and sex of the patients from the Ministry of Health, Labour and Welfare and evaluated it by month, region, age group, and sex.

Results: The total number of patients for the 5 years from 2011 to 2016 was 105,025. There were 29,224 male and 75,801 female participants, with a female-to-male ratio of 2.6. The mean age was 60.2 (standard deviation, 20.8) years. Distal radius fractures occurred more frequently in the winter, especially among female individuals in eastern Japan. Female participants aged ≥ 50 years tended to have a higher incidence of distal radius fracture in winter. The incidence of distal radius fracture among male participants aged 0-19 years was higher from spring to autumn.

Conclusion: Surgically treated distal radius fractures occur frequently during the winter months among female individuals in eastern Japan or those aged ≥ 50 years and increase from school age to adolescence, especially in male individuals from spring to autumn. We should be aware of the high incidence of distal radius fractures in winter, especially in regions with snowfall and cold temperatures.