A rare case of supinator syndrome caused by osteofibrous dysplasia of the radius.

We report the case of a 57-year-old male who presented to our emergency room due to progressive paresis of the muscles innervated by the deep branch of the radial nerve in the right forearm. The patient suffered from osteofibrous dysplasia and an x-ray revealed the polyostotic disease had also affected his radius. High resolution ultrasound revealed that an exostosis of the radius had caused compression of the posterior interosseous nerve unusually distally in the supinator tunnel. The patient underwent nerve decompression and recovered full strength in his wrist-, and finger extensors approximately 9 months postoperatively. This case report illustrates a case of a rare disease, i.e. osteofibrous dysplasia of the radius, in conjunction with the first published report of an unusually located nerve compression syndrome, i.e. supinator syndrome, caused by this very disease.