The purpose of this study was to investigate the role that genetics play in the aetiology and symptomatology of full thickness tears of the rotator cuff.

From a retrospective, cohort study of 205 patients diagnosed with full thickness rotator cuff tears, we determined, using ultrasound, the prevalence of full thickness tears in their 129 siblings. Using 150 spouses as controls, the relative risk of full thickness rotator cuff tear in siblings v controls was 2.42 (p< 0.0001, 95 % CI 1.77 to 3.31). The relative risk of symptomatic full thickness rotator cuff tear in siblings v controls was 4.65 (p< 0.0001, 95 % CI 2.42 to 8.63).

The significantly increased risk for tears in siblings implies that genetic factors play a major role in the development of full thickness tears of the rotator cuff.