PURPOSE: The purpose of this study is to investigate the incidence of acute Achilles tendon rupture in Denmark from 1994 to 2013 with focus on sex, age, geographical areas, seasonal variation and choice of treatment.

METHODS: The National Patient Registry was retrospectively searched to find the number of acute Achilles tendon rupture in Denmark during the time period of 1994-2013. Regional population data were retrieved from the services of Statistics Denmark.

RESULTS: During the 20-year period, 33,160 ruptures occurred revealing a statistically significant increase in the incidence (p < 0.001, range = 26.95-31.17/100,000/year). Male-to-female ratio was 3:1 and average age 45 years for men and 44 years for women. There was a statistically significant increasing incidence for people over 50 years. A higher incidence in rural compared with urban geographical areas was found, but this was not statistically significant. There was a statistically significant decreasing incidence of patients treated with surgery from 16.9/10(5) in 1994 to 6.3/10(5) in 2013.

CONCLUSIONS: The incidence of acute Achilles tendon rupture increased from 1994 to 2013 based on increasing incidence in the older population. There was no difference in incidence of acute Achilles tendon rupture in the rural compared with urban geographical areas. A steady decline in surgical treatment was found over the whole period, with a noticeable decline from 2009 to 2013, possibly reflecting a rapid change in clinical practice following a range of high-quality randomized clinical trials (RCT).

LEVEL OF EVIDENCE: IV.