Throwing shoulder injury involving the anterior rotator cuff: concealed tears not as uncommon as previously thought

In throwing athletes, partial rotator cuff tears are usually located posterior to the site of the common rotator cuff tears seen in the general nonthrowing population. However, they sometimes have tears located around the anterior aspect of the supraspinatus tendon. In this study we investigated the characteristics of anterior rotator cuff tears in throwing athletes. We then compared several factors between anterior tears and posterior tears to investigate those related to the presence of anterior tears or the occurrence of such tears.

We divided 37 athletes with partial rotator cuff tears into those with anterior tears (n = 17) and those with posterior tears (n = 20). The clinical profile, range of motion and joint laxity with patient under general anesthesia, and operative findings were retrospectively compared between the 2 groups.

Among the 17 anterior rotator cuff tears, 12 tears were confined to the anterior one third of the supraspinatus tendon. Interestingly, concealed intratendinous degenerative tears were found in 6 shoulders. These appeared to be very shallow articular-side tears located around the attachment of the greater tuberosity, but severe tears were exposed after resection of the residual capsular portion of the tendon. Posterior capsular tightness was significantly related to the occurrence of anterior tears, whereas a greater tuberosity notch was significantly related to posterior tears.

Anterior rotator cuff tears are not uncommon in throwing athletes, and a concealed type of tear was a representative lesion. Different mechanisms may be involved in the development of anterior and posterior rotator cuff tears resulting from throwing injuries. Posterior capsular tightness might influence the occurrence of anterior tears.

Level IV, prognostic case series.