The ulnar nerve comes from the medical cord of the brachial plexus (C8-T1). It travels out of the axilla along the medial border of the arm to pass into the forearm via the cubital tunnel at the elbow. Cubital tunnel syndrome is the result of compression and traction on the ulnar nerve about the elbow, which can occur at multiple sites. The most proximal possible site of compression causing is the arcade of Struthers. This entity has been described as an aponeurotic band, as a fibrous canal or as thickened connective tissue. Regardless of the nomenclature, ulnar nerve compression has been documented at the location of the arcade of Struthers, which is 6 to 10 cm proximal to the medial epicondyle. Simple open in situ decompression typically results in decompression of the ulnar nerve 6 cm proximal and 6 cm distal to the medial epicondyle while endoscopic ulnar nerve decompression decompresses on average 17 cm of the ulnar nerve (range 25-23 cm), thus consistently reaching the area of the arcade of Struthers. Recurrent cubital tunnel syndrome after simple decompression can be due failure to the release of the arcade of Struthers, and the revision surgery involved extending the incision and length of ulnar nerve release. With the advances in ultrasound imaging, the identification of the arcade of Struthers in mid arm is feasible. hence, it would be beneficial to identify the presence and the location of the arcade of Struthers pre-operatively, to direct the surgical procedure to decompress the ulnar nerve more proximally in cases of a simple decompression in situ.
To determine the correlation between the presence of the arcade of Struthers on preoperative ultrasound and during endoscopic surgery for cubital tunnel syndrome, and to determine the reliability of a portable ultrasound probe to detect the arcade of Struthers in the arm.