High incidence of acute full-thickness rotator cuff tears: A population-based prospective study in a Swedish Community

BACKGROUND AND PURPOSE: Epidemiological studies of full-thickness rotator cuff tears (FTRCTs) have mainly investigated degenerative lesions. We estimated the population-based incidence of acute FTRCT using a new diagnostic model. PATIENTS AND METHODS: During the period November 2010 through October 2012, we prospectively studied all patients aged 18–75 years with acute onset of pain after shoulder trauma, with limited active abduction, and with normal conventional radiographs. 259 consecutive patients met these inclusion criteria. The patients had a median age of 51 (18–75) years. 65% were males. The patients were divided into 3 groups according to the clinical findings: group I, suspected FTRCT; group II, other specific diagnoses; and group III, sprain. Semi-acute MRI was performed in all patients in group I and in patients in group III who did not recover functionally. RESULTS: We identified 60 patients with FTRCTs. The estimated annual incidence of MRI-verified acute FTRCT was 16 (95% CI: 11–23) per 10(5) inhabitants for the population aged 18–75 years and 25 (CI: 18–36) per 10(5) inhabitants for the population aged 40–75 years. The prevalence of acute FTRCT in the study group was 60/259 (23%, CI: 18–28). The tears were usually large and affected more than 1 tendon in 36 of these 60 patients. The subscapularis was involved in 38 of the 60 patients. INTERPRETATION: Acute FTRCTs are common shoulder injuries, especially in men. They are usually large and often involve the subscapularis tendon.