[Radial nerve entrapment in the spiral groove. Nerve block as a diagnostic and therapeutic tool].

The radial nerve has a long and sinuous course in the upper limb from the axilla to the hand and fingers. There are several possible areas of compression along this trajectory, the most frequent being on the Arcade of Frohse, with entrapment of its terminal nerve, the posterior interosseous nerve. We report the case of a patient with radial nerve entrapment in the spiral groove and describe how ultrasound and nerve blocks could be useful in diagnosis and treatment. In our patient, nerve block at the main radial nerve in the spiral groove was insufficient. A second nerve block was needed in the inferior lateral cutaneous nerve of the arm to achieve an optimal clinical result.