Study: Sound-Side Rotator Cuff Degeneration Not Worsened by Overuse

A study, conducted to assess whether overuse of the sound-side shoulder among people with unilateral arm amputation has a role in rotator cuff tears, found that rotator cuff degeneration was no higher than the rate among subjects without amputations, but that rotator cuff degeneration was higher on the side with the amputation. The study’s authors note that because the prevalence of rotator cuff degeneration/tear was shown to be higher on the side with the amputation, nonuse is a more relevant risk factor than overuse. In clinical practice, patients with rotator cuff tears should be encouraged toward shoulder movement because rotator cuff tendon status could be worsened by disuse.
The study cohort included 19 men and six women (mean age: 57.3 ± 10.1) who had unilateral arm amputations more than 20 years ago. Each participant received MRIs of both shoulders. Tendon status and muscle tropism were evaluated according to Sugaya and Fuchs classifications, and the acromiohumeral distance was measured. Statistical analysis was performed to verify the Sugaya and Fuchs categories in each side.
The researchers found a significant prevalence of Sugaya type II (sufficient thickness compared with normal cuff associated with partial high-intensity area) in the participants’ amputated sides and of type I (sufficient thickness compared with normal cuff with homogenously low intensity on each image) in their healthy sides. The rotator cuff was healthy in 28 percent of amputated sides and 52 percent of non-amputated sides. The mean acromiohumeral distance was 0.8cm in the amputated side and 0.9cm in the healthy side. A significant prevalence of Fuchs type II was found in the healthy side. Fuchs type III/IV were observed in 40 percent and 12 percent of amputated and healthy sides, respectively.
The study was published online July 13 in Knee Surgery, Sports Traumatology, Arthroscopy.