Fig. 14

Example of a pathology of the deep peroenal (fbular) nerve. Ultrasound images of left common peroneal (fibular) nerve in a patient presented with left foot drop. A Short-axis view of the common fibular nerve at the fibular head showing normal appearance and average nerve cross-sectional area. Note how the nerve consists of anterior bundle which will eventually form the deep peroneal nerve and posterior bundle which will eventually form the superficial peroneal nerve. B Short-axis view of the common fibular nerve distal to the fibular head and just proximal to the fibular tunnel showing a well-defined anechoic avascular and non-compressible swelling emerging from the anterior bundle consistent with intraneural ganglion cyst. Note that the posterior nerve bundle is intact with preserved fascicular pattern. C Short-axis view of the CFN at the fibular tunnel distal to the swelling level showing normal appearance of the deep and superficial fibular nerves. D Long-axis view of the cyst showing its continuity with the nerve