Ultrasound-guided surgical treatment for ulnar nerve entrapment: a cadaver study

Several open and endoscopic techniques for the surgical treatment of ulnar nerve entrapment at the elbow (cubital tunnel syndrome) have been described that provide decompression with or without anterior transposition. Based on our experience with US-guided decompression for carpal tunnel syndrome in our department, we developed a similar surgical technique for the decompression of the ulnar nerve at the elbow. Using sixteen cadaver upper limbs, we performed decompression of all the structures possibly responsible for ulnar nerve compression at the elbow. The structures involved were Struthers' arcade, the cubital tunnel retinaculum, Osborne's fascia and Amadio-Beckenbaugh's arcade. The procedure was followed by anatomical dissection to confirm complete sectioning of the compressive structures, absence of iatrogenic vascular or nervous injuries and absence of nerve dislocation or instability. There were no remaining compressive structures after the release procedure. There was no iatrogenic damage to the nerves and no nerve dislocation was observed during elbow flexion or extension. In 3.4% cases, a thin superficial layer of one or more of the identified structures remained but these did not appear to compress the nerve based on US imaging. Using ultrasonographic visualization of the nerve and compressive structures is easy. Each procedure can be tailored according to the nerve compression sites. Our cadaveric study shows the feasibility of an US-guided percutaneous surgical release for ulnar nerve entrapment.