Key Risk Factor for Rotator Cuff Retear Identified

A high acromion-greater tuberosity impingement index increases the risk of retear after arthroscopic rotator cuff repair, a new study finds.

The study, “A high acromion-greater tuberosity impingement index increases the risk of retear after arthroscopic rotator cuff repair,” was published online on April 18, 2022 in the Journal of Orthopaedic Surgery.

“No evaluation has been done on the relationship of the acromion-greater tuberosity impingement index with retear after arthroscopic rotator cuff repair. Our purpose was to evaluate whether a higher acromion-greater tuberosity impingement index is associated with retear after arthroscopic rotator cuff repair,” the researchers wrote.

One hundred and thirty-two patients who underwent arthroscopic rotator cuff repair were checked by the research team using an MRI scan at a one year follow-up to check tendon healing. All findings were graded no retear, partial-thickness retear or full-thickness retear.

The acromion-greater tuberosity impingement index, the critical shoulder angle, acromion index and lateral acromial angle were all measured with postoperative radiographs.

Postoperative Constant scores and American Shoulder and Elbow Surgeons scores were different across all groups, with inferior outcomes in the full-thickness retear group (p < 0.05 for all). The University of California at Los Angeles Shoulder Score was improved more in the no retear group as compared with the partial-thickness retear and the full-thickness retear groups (p < 0.05), and in the partial-thickness retear group compared with the full-thickness group (p < 0.05).

For high acromion-greater tuberosity impingement index and critical shoulder angle, the values of the partial-thickness and full-thickness retear groups were larger than the no retear group (p < 0.05 for all); however, there were no significant differences between the partial retear and full retear groups.

The researchers also observed no significant differences with regard to the acromion index or the lateral acromial angle. In addition, the repair integrity was positively related to the acromion-greater tuberosity impingement index (0.304, p < 0.05) and critical shoulder angle (0.252, p < 0.05), but not related to the acromion index or the lateral acromial angle. The acromion-greater tuberosity impingement index was not related to any functional scores (p > 0.05 for all).

“This study revealed that the acromion-greater tuberosity impingement index was positively related to rotator cuff retear. Patients with retears had significantly greater acromion-greater tuberosity impingement index scores after arthroscopic rotator cuff repair,” the researchers wrote.

Study authors included Linghui Xie, B.S., of Wenzhou Seventh Hospital in China, Xinxian Xu, M.S., of The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University in China, Baoxiang Ma, B.S., of Wenzhou Seventh Hospital in China and Haixiao Liu, Ph.D., of The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University in China.