x
x

POSTERIOR INTEROSSEOUS NERVE PALSY

Introduction

The posterior interosseous nerve (PIN) is a deep branch of the radial nerve and is principally a motor nerve. PIN palsy is a rare syndrome characterized by reduced ability to extend the fingers, weakened extension and abduction of the thumb and wrist extension with a radial drift.1–3 Potential causes include PIN or radial nerve lesions or entrapment of the PIN as it passes through the radial tunnel3,4 or by tumors.5,6 Patients may report dull pain in the forearm and/or elbow that is aggravated by activity, but there is no loss of sensation.7  

Pathophysiology

  • Mechanical causes of PIN palsy include2,11,12
    • Spontaneous compression under the Arcade of Froshe is considered the most frequent cause3
    • Space-occupying lesions such as as lipomas, neurofibromas, haemangiomas, synovial chondromatosis, chondromas, myxomas, ganglions, bursitis, rheumatoid synovitis, pseudogout 5
    • Impingement by hypertrophic synovium from the elbow (a fibrous arch is suggested to be a predisposing factor)
    • Tenosynovitis
    • Monteggia fractures
    • Dislocation of the radial head
    • Trauma
    • Repetitive overuse
  • Non-mechanical causes include
    • Selective proximal lesions of the radial nerve such as spontaneous "hourglass" constriction1,11,12
    • Other conditions such as rheumatoid arthritis (RA), mononeuritis, or diabetes
    • Peripheral neuropathy in RA secondary to medications
  • Less common disorders such as motor neuron disease, multifocal motor neuropathy, hereditary brachial plexopathy, monomelic amyoptrophy and Parsonage-Turner Syndrome 1,11,12 

Related Anatomy

  • The PIN innervates the following muscles:4
    • Supinator
    • Extensor carpi radialis brevis (ECRB)
    • Extensor digitorum communis (EDC)
    • Extensor digiti minimi (EDM)
    • Extensor carpi ulnaris (ECU)
    • Abductor pollicis
    • Extensor pollicis brevis (EPB)
    • Extensor pollicis longus (EPL)
    • Extensor indicis
  • Potential sites of PIN compression1,4
    • Fibrous bands at the proximal edge of the ECRB
    • Thickened fascia superficial to the radiocapitellar joint between the brachialis and brachioradialis,
    • Leash of Henry
    • Arcade of Froshe
    • Distal edge of the supinator
    • Tumors compressin the nerve

Incidence and Related Conditions

  • Annual incidence of PIN palsy is estimated to be 0.003% and accounts for <0.7% all upper-extremity peripheral neuropathies1

Differential Diagnosis

  • Lateral epicondylitis
  • Radial nerve injury
  • Radial tunnel syndrome
  • Cervical radiculopathy or cervical spondylosis 
  • Brachial neuritis
  • Parsonage-Turner Syndrome (idiopathic brachail plexopathy)
ICD-10 Codes

  • POSTERIOR INTEROSSEOUS NERVE PALSY

    Diagnostic Guide Name

    POSTERIOR INTEROSSEOUS NERVE PALSY

    ICD 10 Diagnosis, Single Code, Left Code, Right Code and Bilateral Code

    DIAGNOSISSINGLE CODE ONLYLEFTRIGHTBILATERAL (If Available)
    POSTERIOR INTEROSSEOUS NERVE PALSY, INJURY, FOREARM S54.8X2_S54.8X1_ 

    Instructions (ICD 10 CM 2020, U.S. Version)

    THE APPROPRIATE SEVENTH CHARACTER IS TO BE ADDED TO EACH CODE FROM CATEGORY S54
    A - Initial Encounter
    D - Subsequent Routine Healing
    S - Sequela

    ICD-10 Reference

    Reproduced from the International statistical classification of diseases and related health problems, 10th revision, Fifth edition, 2016. Geneva, World Health Organization, 2016 https://apps.who.int/iris/handle/10665/246208

Clinical Presentation Photos and Related Diagrams
Posterior Interosseous Nerve Palsy Clinical Presentation
  • 58 y.o. right handed male with a PIN palsy complaining of proximal forearm pain and inability to straighten his fingers on the left.
    58 y.o. right handed male with a PIN palsy complaining of proximal forearm pain and inability to straighten his fingers on the left.
  • A mass was palpable in the primal dorsal forearm (arrow)
    A mass was palpable in the primal dorsal forearm (arrow)
  • Elderly female with chronic PIN palsy who can not extend her fingers or thumb and notes deviation with wrist extension (arrow on ECRL).
    Elderly female with chronic PIN palsy who can not extend her fingers or thumb and notes deviation with wrist extension (arrow on ECRL).
Symptoms
Absent to dull to severe pain in the forearm and/or elbow
Inability to extend the fingers at the metacarpophalangeal (MP) joints
Weakness or loss of thumb extension and abduction
Radial drift in wrist extension
No numbness complaints
Typical History

The typical patient is a middle-aged, right-handed female who overused her supinator muscles playing tennis 3 times a week. She presented to her primary care physician with complaints of episodic pain (no pain in her neck or shoulders) and increasing inability to extend her index and long fingers. Upon examination, the physician observed weakened wrist extension with radial deviation and weak finger extension. Sensory testing showed no deficits. 

Positive Tests, Exams or Signs
Work-up Options
Treatment Options
Treatment Goals
  • Identify the diagnosis of posterior interosseous nerve (PIN) palsy accurately
  • Define the PIN palsy as mechanical or non-mechanical
  • Provide appropriate treatment that will improve or correct the patients motor deficiencies
Conservative
  • Observation for 6 to 8 weeks
  • Anti-inflammatory medications or corticosteroid injections
  • Activity modification
  • Splinting
  • Physical therapy
Operative
  • Surgery is recommended when imaging shows a space-occupying lesion or no signs of recovery are observed after 3 months of conservative treatment
  • Exploration of the radial tunnel and decompression is recommended
  • The posterior interosseous nerve can be neurolysed with an anterior, posterior or lateral surgical approach12
Treatment Photos and Diagrams
Mechanical PIN Palsy Surgical Treatment
  • Lipoma causing a posterior interosseous nerve (arrow) palsy. Insert with excised tumor.
    Lipoma causing a posterior interosseous nerve (arrow) palsy. Insert with excised tumor.
  • Note the area of compression (arrow) in the posterior interosseous nerve after lipoma excision.
    Note the area of compression (arrow) in the posterior interosseous nerve after lipoma excision.
  • After lipoma excision patient did not regain complete extension (insertion). His deficiency was corrected with a site-to-side tendon transfer (arrow).
    After lipoma excision patient did not regain complete extension (insertion). His deficiency was corrected with a site-to-side tendon transfer (arrow).
  • Another potential mechanical compression - radius fracture undergoing ORIF. Note compression area on the PIN (arrow).
Non-mechanical PIN Palsy Surgical Treatment
  • The superficial head of the supinator muscle has been cut. Note branching of the PIN at the probe tip.
    The superficial head of the supinator muscle has been cut. Note branching of the PIN at the probe tip.
  • Supinator and arcade of Froshe have been release. Note area of compression at the arrow.
    Supinator and arcade of Froshe have been release. Note area of compression at the arrow.
  • Posterior approach to the PIN. Note healthy ECRL innervated proximal to the PIN and pale finger extensor muscles distal to the entrapment. Muscle biopsy of EDC showed early denervation atrophy.
    Posterior approach to the PIN. Note healthy ECRL innervated proximal to the PIN and pale finger extensor muscles distal to the entrapment. Muscle biopsy of EDC showed early denervation atrophy.
CPT Codes for Treatment Options

Per an agreement between Hand Surgery Resource, LLC and the American Medical Association (AMA) users are required to accept the following End User Point and Click Agreement in order to view CPT content on this website.  Please read and then click "Accept" at the bottom to indicate your acceptance of the agreement.

End User Point and Click Agreement

CPT codes, descriptions and other data only are copyright 2019 American Medical Association (AMA). All rights reserved. CPT is a registered trademark of the AMA. The AMA reserves all rights to approve any license with any Federal agency.

You, as an individual, are authorized to use CPT only as contained in Hand Surgery Resource solely for your own personal information and only within the United States for non-commercial, educational use for the purpose of education relating to the fundamental principles of hand surgery and the common diseases, disorders and injuries affecting the human hand. You agree to take all necessary steps to ensure your compliance with the terms of this agreement.

Any use not authorized herein is prohibited, including by way of illustration and not by way of limitation, making copies of CPT for resale and/or license, transferring copies of CPT to any party not bound by this agreement, creating any modified or derivative work of CPT, or making any commercial use of CPT. License to use CPT for any use not authorized herein must be obtained through the AMA, CPT Intellectual Property Services, 330 N. Wabash Avenue, Chicago, IL 60611. Applications are available at the AMA Web site, http://www.ama-assn.org/go/cpt.

Complications
  • Failure to improve motor function
  • Infection after surgical treatment
  • Persistent pain
Outcomes
  • Conservative therapy yields good outcome after 3 months, if there are no space-occupying lesions or other mechanical causes of compression
  • >75% of patients recover within 2–18 months of surgical intervention9
  • Patients who have slower progression of symptoms may have a poorer prognosis10
Key Educational Points
  • Use electrodiagnostic studies and imaging (MRI) to identify the cause of PIN palsy ensures good outcome
  • Symptoms and signs of PIN palsy include: inability to extend the fingers at MP joints, pain aggravated by pronation and supination, wrist extension with radial drift and decreased thumb abduction 
  • Whether the PIN palsy is casued by a mechanical or non-mechanical probelm, the nerve dysfunction is secondary to neural ischemia.12
  • The cause of Parsonage-Turner Syndrome is unkown11,12
  • MRI is the prefered imaging study but ultrasound can be helpful when evaluating dynamic PIN compression12
  • If  the PIN palsy is caused by a mass, for example a lipoma, then early excision of the tumor and posterior interosseous nerve neurolysis is indicated.
  • Non-mechanical PIN palsy can be caused by neural amyotrophy and spontaneous recovery without surgery can occur.  In these neurologic disorders improvement can be event within a month and 73% of the patients can improve by a year.11,12
  • PIN palsy caused by an entrapment looks clinically the similar to PIN palsy caused by amyopathy but true entrapment will not improve with time. Therefore, if the symptoms and signs are not improving by 6-8 weeks then surgical exploration and posterior interosseous nerve neurolysis is indicated.
References

Cited

  1. Bevelaqua A-C, Hayter CL, Feinberg JH, Rodeo SA. Posterior interosseous neuropathy: electrodiagnostic evaluation. HSS J Musculoskelet J Hosp Spec Surg 2012;8(2):184–9. PMID: 23874261
  2. Chan JKK, Kennett R, Smith G. Posterior interosseous nerve palsy in rheumatoid arthritis: case report and literature review. J Plast Reconstr Aesthetic Surg 2009;62(12):e556-560. PMID: 19046665
  3. Cravens G, Kline DG. Posterior interosseous nerve palsies. Neurosurgery 1990;27(3):397–402. PMID: 2172858
  4. Cha J, York B, Tawfik J. Posterior interosseous nerve compression. Eplasty 2014;14:ic4. PMID: 24570771
  5. Colasanti R, Iacoangeli M, Di Rienzo A, et al. Delayed diagnosed intermuscular lipoma causing a posterior interosseous nerve palsy in a patient with cervical spondylosis: the “priceless” value of the clinical examination in the technological era. G Chir 2016;37(1):42–5. PMID: 27142825
  6. Allagui M, Maghrebi S, Touati B, et al. Posterior interosseous nerve syndrome due to intramuscular lipoma. Eur Orthop Traumatol 2014;5:75–9. PMID: 24634698
  7. Mulholland RC. Non-traumatic progressive paralysis of the posterior interosseous nerve. J Bone Joint Surg Br 1966;48(4):781–5. PMID: 4288962
  8. Baumer P, Kele H, Xia A, et al. Posterior interosseous neuropathy: Supinator syndrome vs fascicular radial neuropathy. Neurology 2016;87(18):1884–91. PMID: 27683851
  9. Knutsen EJ, Calfee RP. Uncommon upper extremity compression neuropathies. Hand Clin 2013;29(3):443–53. PMID: 23895725
  10. Ochi K, Horiuchi Y, Tazaki K, et al. Slow progression predicts poor prognoses in patients with spontaneous posterior interosseous nerve palsy. J Plast Surg Hand Surg 2013;47(6):493–7. PMID: 23596993
  11. Feinberg JH, Radecki J. Parsonage-Turner Syndrome. HSS J 2010 Sep; 6(2): 199–205.    PMID: 21886536
  12. Sigamoney KV, Rashid A, Chye YN.   Management of Atraumatic Posterior Interosseous Nerve Palsy.  J Hand Surg Am. 2017; 42(10):826-830.

Articles

  1. Baumer P, Kele H, Xia A, et al. Posterior interosseous neuropathy: Supinator syndrome vs fascicular radial neuropathy. Neurology 2016;87(18):1884–91. PMID: 27683851
  2. Colasanti R, Iacoangeli M, Di Rienzo A, et al. Delayed diagnosed intermuscular lipoma causing a posterior interosseous nerve palsy in a patient with cervical spondylosis: the “priceless” value of the clinical examination in the technological era. G Chir 2016;37(1):42–5. PMID: 27142825
  3. Bevelaqua A-C, Hayter CL, Feinberg JH, Rodeo SA. Posterior interosseous neuropathy: electrodiagnostic evaluation. HSS J Musculoskelet J Hosp Spec Surg 2012;8(2):184–9. PMID: 23874261
  4. Knutsen EJ, Calfee RP. Uncommon upper extremity compression neuropathies. Hand Clin 2013;29(3):443–53. PMID: 23895725
  5. Sigamoney KV, Rashid A, Chye YN.   Management of Atraumatic Posterior Interosseous Nerve Palsy.  J Hand Surg Am. 2017; 42(10):826-830.

Classic

  1. Mulholland RC. Non-traumatic progressive paralysis of the posterior interosseous nerve. J Bone Joint Surg Br 1966;48(4):781–5. PMID: 4288962
Subscribe to POSTERIOR INTEROSSEOUS NERVE PALSY
⇡