The Prevalence of Pronator Teres among Patients with Carpal Tunnel Syndrome: Cross-sectional Study

The aim of conducting this study was to determine the prevalence of PTS among patients with carpal tunnel syndrome. The study was conducted from March 2014 to April 2015 in the EDX ward and clinic of physical medicine and rehabilitation at the university hospital; Baqiytallah, a large referral practice and research center in Tehran. We included patients with clinical symptoms and signs of CTS. Clinical assessments were aimed to the diagnosis of CTS and PTS. At the next stage, ultrasound study was performed for the participants with suspected CTS. Sample size calculations were based on the formula: N=4[pq/w2]z1-α/22. Results showed that 13 (8.8%) patients presented electrodiagnostic, and 27 (18.2%) had clinical manifestations of pronator teres syndrome of which, 17 showed ultrasonic signs of the syndrome. In addition, 2, 7, and 8 out of the 17 patients had mild, moderate, and sever carpal tunnel syndrome, respectively. Age was not significantly different between the patients with, and without pronator teres syndrome (p-value=0.179). Nine participants with pronator teres syndrome were male and there was a significant difference concerning sex (p-value=0.013). There was a good agreement between electrodiagnostic and ultrasound findings (Cohen’s kappa coefficient=0.71, p-value<0.0001). Taken together, pronator teres syndrome should be considered as a possibility among patients with carpal tunnel syndrome especially in sever forms. Both electrodiagnostic and sonographic studies are efficient for diagnosing pronator teres syndrome. Men are more prone to develop pronator teres syndrome.