Superoxide-induced oxidative stress may be a contributing factor for retear after arthroscopic rotator cuff repair, new research shows.
“Recurrent tears after arthroscopic rotator cuff repair (ARCR) remain a significant clinical problem. Oxidative stress contributes to the degeneration of the rotator cuff, and a degenerative rotator cuff can lead to recurrent tear after ARCR. However, the correlation between oxidative stress and retear after ARCR is unclear,” the researchers of “Association of Recurrent Tear After Arthroscopic Rotator Cuff Repair and Superoxide-Induced Oxidative Stress,” wrote.
The study which was published online in The American Journal of Sports Medicine on May 20, 2021 looked specifically at ARCR cases using a suture-bridge technique. Sixty-eight patients in total were included in the case-control study.
The research team analyzed specimens collected from the edge of the torn tendon during surgery. They used a modified Bonar score to measure the level of degeneration, and fluorescence intensity on dihydroethidium staining to detect oxidative stress. They also reported on superoxide dismutase enzyme activity.
The team also collected data regarding the age of patient, tear size on magnetic resonance imaging (MRI) before surgery, Goutallier classification on MRI before surgery, and Japanese Orthopaedic Association score before and 6 months after surgery.
After their 6 month evaluation, the patients were divided into two groups. The healed rotator group consisted of 46 of the patients, while the recurrent tear group had 22 patients. The researchers looked at clinical outcomes including modified Bonar score, dihydroethidium intensity and superoxide dismutase enzyme activity to determine the most significant differences between the two groups.
Overall, age, tear size, Goutallier classification, modified Bonar score, dihydroethidium intensity and superoxide dismutase enzyme activity were all significantly greater in the retear group. The Japanese Orthopaedic Association scores were not.
Multiple logistic regression analysis confirmed that age, tear size, dihydroethidium intensity and superoxide dismutase enzyme activity were associated with recurrent tear.
“In addition to tear size and age, superoxide-induced oxidative stress may be an exacerbating factor for retear after ARCR,” the researchers wrote.
