Cigarette smokers have an increased risk of experiencing rotator cuff tears in their shoulders than their tobacco-free counterparts, according to study results presented today at the 72nd Annual Meeting of the American Academy of Orthopaedic Surgeons. Previous studies analyzed the correlation between tobacco use and musculoskeletal injuries, but did not focus specifically on the impact smoking has on this unilateral shoulder injury.
A team of researchers from the Washington University School of Medicine - Barnes Jewish Hospital interviewed 586 patients ages 18 years and older who had a diagnostic shoulder ultrasound for shoulder pain with no prior history of shoulder surgery. Of this group, 375 patients had a rotator cuff tear and 211 patients did not.
Lead author of the study, Keith M. Baumgarten, MD, orthopaedic surgeon at the Hospital for Special Surgery, New York City, and his team from Washington University developed a standardized questionnaire that was administered to all 586 patients to determine the demographic, medical, pharmaceutical and lifestyle factors that may pose an increased risk for rotator cuff tears. Patients who did, indeed, have rotator cuff tears were compared to patients without this injury to determine if there was any correlation between rotator cuff tears and demographic risk factors.
"Our questionnaire data show that significantly more patients with rotator cuff tears had a history of daily tobacco smoking compared to patients without rotator cuff tears," said Dr. Baumgarten. "Patients with rotator cuff tears were also more likely to have smoked regularly within the ten years before arriving at our clinic for evaluation of their shoulder pain. This data clearly suggests that tobacco use increases the risk for rotator cuff tears."
The study demonstrated a dose-dependent relationship between tobacco use and rotator cuff tears, since patients with rotator cuff tears had a statistically significant increase in 1) the average number of packs of tobacco consumed per day; 2) the duration of smoking history; and 3) the average number of pack-years of tobacco use.
According to Dr. Baumgarten, the results of this study are biologically plausible because smoking has been shown to impair healing of other biologic tissues, specifically bone and skin. Nicotine has been shown in previous studies to decrease production of fibroblasts (the main cells responsible for tissue repair). In addition, the carbon monoxide found in tobacco smoke reduces cellular oxygen tension levels, which are vital for cellular metabolism and tissue healing.
Taking into consideration medical conditions, the study also found that there was a statistically significant increase in rotator cuff tears among patients with rheumatoid arthritis.
Between the two groups, there were no significant differences found in frequency of exercise or weightlifting. While manual labor has been previously been associated with shoulder tendonitis, there was no difference between the two groups when comparing sedentary work environments to occupations requiring manual labor in regards to the impact on rotator cuff tears.
"Advanced age, tobacco use and rheumatoid arthritis are risk factors that increase a person's chances of experiencing a rotator cuff tear," said Dr. Baumgarten.
An orthopaedic surgeon is a physician with extensive training in the diagnosis and non-surgical as well as surgical treatment of the musculoskeletal system, including bones, joints, ligaments, tendons, muscles and nerves.