The investigators want to compare changes in CSA of the ulnar nerve at the elbow hypothesizing that US examination is a useful tool to detect unsuccessful release and defining which technique shows the best outcome in the first year postoperatively.~The measurement of cross-sectional area (CSA) as a diagnostic tool to detect entrapments syndrome in upper limbs has already been described. US typically demonstrates an abrupt narrowing and displacement of the nerve within the tunnel, possibly in association with a thickened retinaculum or a space-occupying lesions. Previous studies prospectively compared sonographic outcomes after decompression of the median nerve at the wrist.
The investigators want to compare changes in cross-sectional area (CSA) of the ulnar nerve at the elbow after open release or endoscopic release.