Abstract
Rotator cuff tear was one of the typical diseases causing pain in the shoulder joint, but it is also known that asymptomatic rotator cuff tear occured with aging. This study investigated the clinical epidemiology of asymptomatic rotator cuff tears. Local medical examinations were given to 5,660 residents of a village. Of these, 683 people (1,366 shoulders) were included in this study. The subjects were 229 males and 454 females with an average age of 57.9 years old (range22∼87 years old). Background data were collected by questionnaire including sex, dominant hand, occupation, presence of shoulder joint pain,and the presence or absence of rotator cuff tear was determined by ultrasonography. We classified the subjects into the following 3 groups, symptomatic cuff tear group, asymptomatic cuff tear group, and no tear group, and compared the findings of the 3 groups. Rotator cuff tear was demonstrated in 283 shoulders (total 20.7%), and 185 shoulders (total 13.5%) were asymptomatic.55 shoulders(29.7%) of subjects with asymptomatic rotator cuff tears had previously noticed shoulder pain. The frequency of both symptomatic and asymptomatic tears tended to rise with age. There was no difference between each group in age, sex or dominant hand. Although the frequency of rotator cuff tear was high in the heavy worker compared with the light worker, the difference between symptomatic and asymptomatic was not recognized.
