Anterior rotator cuff tears may be common among throwing athletes, study suggests

Posterior capsular tightness appears significantly associated with the presence of anterior tears.

Partial rotator cuff tears around the anterior aspect of the supraspinatus tendon appear to be more common shoulder injuries among throwing athletes than previously believed, according to a study by researchers in Japan.

"The principle finding of this study was that throwing shoulder injuries frequently involved the anterior rotator cuff," the study authors said.

Shigeto Nakagawa, MD, PhD, and colleagues at Hoshigaoka Kosei-nenkin Hospital in Osaka, reviewed the records for 37 patients treated for articular-side partial rotator cuff tears at the hospital between 2001 and 2004. No patient had a complete tear and none had a bursal-side partial tear, according to the study, which was published in Arthroscopy.

Patients in the study had a mean age of 24 years at the time of surgery and had participated in overhead throwing activities for an average of 14 years.

Of the 37 shoulders, 17 had anterior tears and 20 had posterior tears. Among the 17 shoulders with anterior tears, the tear was limited to the anterior one-third of the supraspinatus tendon in 12 shoulders and involved the anterior two-thirds of the tendon in three shoulders. The tears involved the entire supraspinatus tendon in the remaining two shoulders, according to the study.

Only two of the 12 tears involving the anterior one-third of the supraspinatus tendon were obvious. In four of these 12 shoulders, researchers noted minor avulsion from the greater tuberosity attachment. "In addition, so-called concealed tears were seen in six shoulders, and this seemed to be a representative lesion," the authors said.

These six shoulders with concealed tears had soft tendon surfaces that did not exhibit resistance to probing. Surgeons discovered severe articular-side tears after the residual articular tendon surfaces were resected. Because of this, the researchers considered that only the capsular portion of the tendon remained intact, according to the study.

"Those tears were classified as intratendinous degenerative horizontal tears, and granulation tissue was detected," the authors said, noting such tears were only seen in two of the 20 shoulders with posterior rotator cuff tears.

Posterior capsular tightness was significantly associated with the occurrence of anterior tears, while the presence of a greater tuberosity notch was significantly associated with the occurrence of posterior tears, "suggesting that different pathologic mechanisms are involved in producing anterior and posterior rotator cuff tears," they said.

For more information:
Nakagawa S, Yoneda M, Mizuno N, et al. Throwing shoulder injury involving the anterior rotator cuff: Concealed tears not as uncommon as previously thought. Arthroscopy. 2006;22:1298-1303.