Calcifying Tendinopathy: a Local or a Systemic Condition?

OBJECTIVE To evaluate the relationship between cases of calcifying tendinopathy of the shoulder and symptomatic metabolic diseases such as kidney stones, gallstones and gout. METHODS Calcifying tendinopathy of the shoulder was diagnosed in 63 patients between May 2007 and September 2011. All the patients were treated by the same orthopedic surgeon and were interviewed to gather the following data: age at diagnosis, sex, affected side, dominant side, body mass index (BMI), smoking status and previous histories of kidney stones, gallstones or gout. For statistical analysis, a control group of 63 patients with similar demographic characteristics was used. RESULTS Among the 63 patients with calcifying tendinopathy of the shoulder, 35 (56%) were male. The right side was affected in 38 patients (60%) and the average age was 48.2 years. Thirty-one patients (49%) had histories involving some of the metabolic diseases investigated: 20 patients (32%) reported kidney stones, six (9.5%) gallstones, four (6.3%) gout and one (2%) concurrent diagnoses of kidney stones and gout. In the control group, eleven patients (17%) had histories involving some of the metabolic diseases investigated: six patients (9.5%) reported kidney stones, four (6.3%) gallstones and one (1.6 %) gout. CONCLUSIONS The high frequency of nephrolithiasis in patients with calcifying tendinopathy of the shoulder in our study suggests that there are common mechanisms in the pathophysiology of these disorders. Better understanding of these diseases may enable improvement of diagnostics and treatments.