Prevalence of Pronator Teres Syndrome in patients with CTS.
Carpal tunnel syndrom (CTS) is the most common form of compression of the median nerve. Although this form of compression is mentioned most, there are also cases where the median nerve is compressed between the heads of the Pronator Teres muscle. Between the heads of the Pronator Teres muscle the median nerve enters deep to the tendinous arch connecting the radial and humeral heads.
This compression is also referred to as the Pronator Teres Syndrome (PTS). The symptoms are comparable to CTS, however it is difficult to diagnose PTS. Some treatment options are splints, local injections or surgical decompression, however if the compression is not in the carpal tunnel and if the compression lies within the pronator teres, no such treatment will be effective.
The aim of this study was to determine the prevalence of PTS in patients that present with CTS. Patients with CTS have syptoms such as pain, numbness or paresthesia over the anterior forearm and the 3-5 digits which is aggrevated by pronation. An ultrasound was performed and the median nerve was located between the two heads of the Pronator Teres muscle. Any noticeable reduction in cross-sectional diameter along with decrease in the nerve mobility throughout flexion, supination, and pronation was considered as the criterion for entrapment of the median nerve.
Of the 148 patients with CTS, 40 patients were diagnosed with PTS using ultrasound. 17 of those showed a compression of the median nerve between the two heads of the Pronator Teres muscle. These resuls are comparable to other studies. It seems that ultrasound is suitable for establishing the diagnosis of PTS.
> From: Asheghan et al., Int J Biomed Sci 12 (2017) 89-94(Epub ahead of print). All rights reserved to The Author(s). Click here for the online summary.