On the epidemiology and chronoepidemiology of distal radius fractures

The frequency of distal radius fractures of patients treated in the outpatient clinic of the Herz-jesu-Krankenhaus between Jan. 1997 and Dec. 1999 were evaluated retrospectively. Records of 366 patients (m: 132, f: 234) were assessed. The frequency of distal radius fractures was fitted to a cosine model using non-linear regression in order to detect a circadian or circannual rhythm. The goodness of fit was assessed by means of the F statistics and the coefficient of determination r(2). Moreover, spectral analysis was performed. In 1997 135, in 1938 119, and in 1999 112 distal radius fractures were treated. The mean age of the patients was 40.3 ys. (women: 48.8; men: 25.3). The extended wrist was the most common position during Trauma, Accidents at home (41%), during spare time activities (23.8%), and during physical activities (21.6%) were more frequent than accidents during working hours (12.5%) or traffic accidents (1.7%). The latency for definite surgical treatment in our clinic was 8.5 hours (minimum: 15 min; maximum: 7 days and 14 hours). A significant cosine model could be fitted for a period of 24 hours (r(2) = 0.82) with a maximum at 15.00 hours. Spectral analysis revealed an ultradian rhythm of approximately 12 hours in addition to the circadian periodicity. No significant circannual model could be fitted (r(2) = 0.2), although a slight increase of frequency was found during May and lune. In conclusion, the frequency of distal radius fractures shows a clear circadian but no circannual periodicity.