Figure 11b. Cubital tunnel syndrome in a 47-year-old woman with posttraumatic changes in the elbow resulting in cubitus valgus. Longitudinal 5-12-MHz US scan (a) and transverse 5-12-MHz US scans obtained at the distal arm (b) and within the cubital tunnel (c) show abrupt narrowing of the ulnar nerve (UN) between the thickened floor of the tunnel (*) and the retinaculum (arrowheads). Proximal to the tunnel, the nerve appears swollen and hypoechoic with an absent fascicular pattern.