Posterior Interosseous Nerve Entrapment

• Posterior Interosseous Nerve Entrapment:

  • aka radial tunnel syndrome
  • compression of the posterior interosseous nerve as it travels through the radial tunnel
  • it can be difficult to differentiate between this and lateral elbow tendinopathy and the early stages of nerve entrapment
• Posterior Interosseous Nerve Entrapment / Radial Tunnel Syndrome:

  • what
  • compression of the posterior interosseous nerve
  • where
  • radial tunnel (can occur at several sites) - most common is the Arcade of Frohse
  • how
  • overuse - especially repeated pronation/supination
  • direct trauma
  • space occupying lesion
  • who
  • 30 to 50 year olds
• Posterior Interosseous Nerve Entrapment / Radial Tunnel Syndrome - Subjective Features:

  • diffuse pain from the lateral epicondyle radiating into the forearm and hand
  • pain increases with use/load
  • paraesthesia/anaesthesia into lateral forearm/hand
  • dexterity loss/motor weakness of digit and wrist extension
• Posterior Interosseous Nerve Entrapment / Radial Tunnel Syndrome - Objective Features:

  • palpation
  • tenderness/reproduction of symptoms by palpating the nerve around the radial head (where its most superficial)
  • tenderness over supinator muscle belly
  • upper limb neurological exam
  • +/- paraesthesia/anaesthesia into hand/lateral forearm
  • +/- motor weakness: wrist and finger extensors/supinator
  • neural provocation tests
  • upper limb neural provocation test 2b (tests radial nerve)
  • clearing tests
  • must clear cervical spine and shoulder
• Posterior Interosseous Nerve Entrapment / Radial Tunnel Syndrome - Management:

  • load management
  • ergonomics
  • neural tissue mobilisation
  • address muscle strength deficits/functional weakness
  • soft tissue therapy over the supinator muscle
  • decompression surgery - extreme cases only