Posterior interosseous neuropathy

Background

  • Posterior interosseous nerve (C7-8) is a branch of the radial nerve that supplies motor innervation to the forearm extensor muscles
  • Compression or injury can cause an isolated PIN palsy [1]
  • More proximal pathologies can cause a combined palsy
  • More common in body builders and laborers due to repetitive pronosupination

Causes

  • Peripheral neuropathy
  • Iatrogenic

Clinical Features

  • Forearm and wrist pain
  • Weakness on finger and wrist extension

Differential Diagnosis

Upper extremity peripheral nerve syndromes

Median Nerve Syndromes

Ulnar Nerve Syndromes

Radial Nerve Syndromes

Proximal Neuropathies

Other

Evaluation

Workup

  • Plain films
  • EMG (as outpatient)

Diagnosis

  • Usually a clinical diagnosis (in ED)

Management

  • Nonoperative: rest, activity modification, NSAIDs, splinting
  • Operative decompression: compressive masses

Disposition

  • Discharge with orthopedic follow up

See Also

External Links

References

  1. Dang AC et al. Unusual Compression Neuropathies of the Forearm, Part I: Radial Nerve. JHS. 2009;34A:1906-1914.