Background: Rotator cuff tendinopathy is a common entity. We
hypothesized that obesity, because of biomechanical and systemic risk factors,
increases the risks of rotator cuff tendinitis, tears, and related surgical
Methods: A frequency-matched case-control study was conducted. Three
hundred and eleven patients who were fifty-three to seventy-seven years old
and who underwent rotator cuff repair, arthroscopy, and/or other repair of the
shoulder in a large hospital from 1992 to 2000 were included in the study.
These surgical procedures were used as proxies for the risk of rotator cuff
tendinitis. These patients were age and frequency-matched to 933 controls, who
were randomly drawn from a pool of 10,943 potential controls consisting of
Utah state residents who were enrolled in a large cancer-screening trial.
Age-adjusted odds ratios were calculated with use of the International
Classification of Diseases, Ninth Revision procedural codes and
body-mass-index groups. The data were stratified according to gender and age.
Multiple linear regression analyses also were performed.
Results: There was an association between increasing body-mass index
and shoulder repair surgery. The highest odds ratios for both men (odds ratio
= 3.13; 95% confidence interval = 1.29 to 7.61) and women (odds ratio = 3.51;
95% confidence interval = 1.80 to 6.85) were for individuals with a body-mass
index of =35.0 kg/m2. Tests for trend also were highly
significant for both men (p = 0.002) and women (p = 0.001). Multiple linear
regression analysis also indicated a significant association between
increasing body-mass index and shoulder surgery (beta = 1.57; 95% confidence
interval = 0.97 to 2.17; p = 0.001).
Conclusions: There is an association between obesity and shoulder
repair surgery in men and women who are fifty-three to seventy-seven years of
age. The results of the present study suggest that increasing body-mass index
is a risk factor for rotator cuff tendinitis and related conditions.
Clinical Relevance: Individuals who are obese are at increased risk
for rotator cuff tendinitis and rotator cuff-related surgery. This apparent
risk increases with the degree of obesity.
Level of Evidence: Prognostic study, Level II-1
(retrospective study). See Instructions to Authors for a complete description
of levels of evidence.