[The pronator teres syndrome. Clinical aspects, pathogenesis and therapy of a non-traumatic median nerve compression syndrome in the space of the elbow joint].

The proximal compression neuropathy of the median nerve is described by 11 personal cases and a review of literature. The most reliable diagnostic sign is "pronation-pain", discomfort in the forearm localised under the pronator teres, produced by passive supination of the wrist, by active pronation from this position against resistance, okr by local pressure. A nearly constant finding is weakness of grip and paraesthesia or hypaesthesia of the fingers, not always following the normal median nerve distribution. Three different anatomic points of possible compression are described: 1. The supracondylar process of the humerus, or Struthers' ligament, a rare compression mechanism. 2. The passing of the nerve through the two variable heads of the pronator teres muscle. 3. The sharp edged superficialis bridge. Apart from compression of the entire median nerve single branches of the median nerve can be entrapped seperately (the anterior interosseus nerve, the Martin-Gruber-anastomosis to the ulnar nerve) Conservative treatment with immobilisation and local electric interference current application may be satisfactory. If clinical improvement is insufficient, surgical decompression is indicated.