ST. LOUIS, Oct. 18 (UPI) -- U.S. researchers say exposure to nicotine delays tendon-to-bone healing, suggesting the cause of failure of rotator-cuff repair following surgery.
Orthopaedic surgery researchers at Washington University School of Medicine in St. Louis say the rotator-cuff tears involve one or more of the tendons. The injuries are more common as people age and more common in the dominant arm. However, rotator-cuff repairs can fail in the days and weeks after surgery.
Some studies have reported short- to intermediate-term recurrence rates from 30 percent to 90 percent, depending on the size of the tear, chronic nature of the injury and the age of the patient, among other factors.
"Especially during the first six weeks after surgery, tissue may be vulnerable to re-injury," says Dr. Leesa M. Galatz.
Galatz studied 72 rats following rotator-cuff surgery pumping a nicotine equivalent to smoking a pack to a pack and a half of cigarettes per day or an inactive saline solution.
Measuring properties called maximum stress and maximum force, the researchers found that shoulder joints in the nicotine-exposed rats were weaker, according to the study published in the Journal of Bone & Joint Surgery.
