We investigated the epidemiology of total Achilles tendon ruptures and complication rates after operative and nonoperative treatments over a 33-year period in Oulu, Finland. Patients with Achilles tendon ruptures from 1979 to 2011 in Oulu were identified from hospital patient records. Demographic data, treatment method, and complications were collected retrospectively from medical records. Overall and sex- and age-specific incidence rates were calculated with 95% confidence intervals (CIs). The overall incidence per 100,000 person-years increased from 2.1 (95% CI 0.3-7.7) in 1979 to 21.5 (95% CI 14.6-30.6) in 2011. The incidence increased in all age groups. The mean annual increase in incidence was 2.4% (95% CI 1.3-4.7) higher for non-sports-related ruptures than for sports-related ruptures (P = 0.036). The incidence of sports-related ruptures increased during the second 11-year period whereas the incidence of non-sports-related ruptures increased steadily over the entire study period. Infection was four times more common after operative treatment compared with nonoperative treatment, re-rupture rates were similar. The incidence of Achilles tendon ruptures increased in all age groups over a 33-year period. Increases were mainly due to sports-related injuries in the second 11-year period and non-sports-related injuries in the last 11-year period.

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

NCT02012803 (ClinicalTrials.gov).

Treating ATRs nonsurgically with a functional rehabilitation protocol resulted in greater soleus muscle atrophy compared with surgical treatment. The mean Achilles tendon length was 19 mm longer after nonsurgical treatment than after the surgical treatment of ATRs. These structural changes partly explained the 10% to 18% greater calf muscle strength observed in patients treated with surgery compared with those treated nonsurgically. Registration: NCT02012803 ( ClinicalTrials.gov identifier).