Posterior Interosseous Syndrome
- Description / Cause
- Posterior interosseous nerve (PIN) entrapment at the distal portion of the radial nerve
- Entrapment site
- Arcade of Frohse (superior, fibrous border of the supinator)
- Prevalence / Risk factors
- Common injury due to radial nerve location
- Risk factors
- Cyst
- Triple hourglass-like fascicular constriction of PIN
- Rheumatoid synovitis
- Acute trauma
- Lipoma
- Gunshot wound
- Laceration
- Fracture of proximal radius
- Repeated supination
- Compressive burn injury
- Signs / Symptoms
- Pain
- Lateral humeral epicondyle
- Poorly localized
- With passive elbow extension, forearm pronation, and wrist flexion
- With resisted supination in full elbow extension
- Weakness (grip strength)
- No sensory loss
- Wrist deviation radially with fist clenching
- Extensor carpi ulnaris weakness
- Objective / Special Test
- Index finger extension test
- Weakness
- Compression over radial tunnel
- Wrist extension
- MMT
- Wrist drop
- Finger drop
- Normal
- Triceps
- Supinator
- Anconeus
- Brachioradialis
- Extensor carpi radialis longus
- MDC - handheld dynamometer
- 4%
- Test-retest reliability
- 0.98
- Inter-rater reliability
- 0.94 for patients with spinal cord injury
- Rule of 9 Test
- Anterior aspect of proximal forearm
- Treatment / Interventions
- Physical therapy
- Neural gliding techniques
- Active release technique - soft tissue mobilization
- Extensor carpi radialis brevis
- Supinator
- Arcade of Frohse
- NSAIDs or corticosteroid injection
- Early splinting
- Surgical decompression
- Differential diagnosis
- Lateral epicondyalgia
- PIN
References
- Floranda E, Jacobs B. Evaluation and Treatment of Upper Extremity Nerve Entrapment Syndromes. Primary Care: Clinics In Office Practice [serial online]. December 1, 2013;40(Orthopedics):925-943. Available from: ScienceDirect, Ipswich, MA. Accessed June 30, 2015.
- Robertson E, Reimche, D. Differential Diagnosis for Various Neuropathies at the Elbow. Accessed June 30, 2015.
- Saratsiotis, J; Myriokefalitakis, E. Case Study: Diagnosis and treatment of posterior interosseous nerve syndrome using soft tissue manipulation therapy: A case study. Journal of Bodywork & Movement Therapies. 14, 397-402, Jan. 1, 2010. ISSN: 1360-8592.
Acknowledgements:
David Funk, Student Physical Therapist at A.T. Still University
Ethan Hunke, Student Physical Therapist at A.T. Still University
Morgan Johnson, Student Physical Therapist at A.T. Still University
Ed Nheiu, Student Physical Therapist at A.T. Still University
Lindsay Walczak, Student Physical Therapist at A.T. Still University
Last edited: July 13, 2015