Pronator Teres Compression Syndrome - median nerve compression : Wheeless' Textbook of Orthopaedics

- Discussion:
- see: compression of the median nerve at the elbow and forearm;
- compression of median nerve where it passes between the two heads of the pronator teres;

- Differential Dx:
- lacertus fibrosus:
- draws tightly across the median nerve when the forearm is held in resisted supination and flexion;
- independent flexion of the middle finger flexion (FDS) localizes the level of entrapment to the fibrous arcade of the FDS;
- flexor superficialis crossover syndrome:
- resisted flexion of flexor superficialis of long finger combined w/ parasthesias in forearm & hand while pronating wrist, clinical test for
     median nerve entrapment at pronator teres & flexor superficialis cross over;
- C6 / C7 radiculopathy:
- involvment of these levels will cause numbeness of thumb, index, and long fingers, and the median nerve innervated muscles of the forearm;
- correct diagnosis is made by establishing the function of the muscles innervated by the C6-C7 portions of the radial nerve (ie the
      function of the wrist entensors and the triceps);
         - supracondylar process:
                 - An Unusual Case of Pronator Syndrome With Ipsilateral Supracondylar Process and Abnormal Muscle Mass

- Exam:
- see: exam for carpal tunnel;
- Phalen and tunnel test are negative;
- pain in wrist and forearm;
- weakness of thenar muscles;
- thenar muscles are weak but muscles of ain (fpl, fdp, quad) are spared;
- dysesthesia in "palmar triangle;"
- pronator teres can be implicated when arm is held in resisted pronation and flexion and then gradually extended while in pronated position;

- EMG:
- when EMG does not confirm pronator teres syndrome but clinical evidence is suggestive, then wait 4-6 wks and repeat the EMG;

- Treatment:
- realease of humeral head of pronator teres and the superficialis bridge as well as associated compressing structures

Abnormal musculoaponeurotic tunnel in the arm: possible entrapment of the median nerve and brachial artery with high origin of nerve to pronator teres within the tunnel.

The pronator teres syndrome: compressive neuropathy of the median nerve.