Radial Tunnel Syndrome
Other Names
- Resistant tennis elbow with a nerve entrapment
- Radial Pronator Syndrome
- Supinator Syndrome
- Supinator Channel Syndrome
Background
- This page refers to compression of the Posterior Interosseus Nerve in the forearm, typically referred to as radial tunnel syndrome
History
- Needs to be updated
Epidemiology
- Not well documented in literature
- Annual incidence rate of the posterior interosseous nerve (PIN) compression is estimated 0.03%[1]
Introduction
General
- Compressive neuropathy of the Posterior Interosseus Nerve, a branch of the Radial Nerve
- Compression can occur at one or multiple places
- Characterized by pain only, with no motor or sensory dysfunction
- Some controversy associated with this diagnosis
Potential areas of Compression
- Anterior to the head of the Radius
- Margin of Extensor Carpi Radialis Brevis
- Arcade of Frohse, most common etiology[3]
- Along radial recurrent vessels that innervate the Brachioradialis and Extensor Carpi Radialis Longus muscles
- Fibrous bands anterior to Radiocapitallar Joint
- Radial recurrent vessels (leash of Henry)
- Distal edge of the superficial layer of the Supinator
- Compressive mass effect: tumor, lipoma, hemangioma, accessory muscles
Anatomy of the Radial Tunnel
- Extends from radiocapitellar joint to just past the proximal edge of supinator
- Approximately 5 cm in length
- Anatomic borders
- Lateral: Brachioradialis, ECRB, ECRL
- Medial: Biceps Brachii tendon, Brachialis
- Floor: capsule of radiocapitellar joint
Anatomy of the Posterior Interosseous Nerve
- Branch of radial nerve
- Function: innervates extensor muscles of forearm and wrist
Associated Conditions
- Lateral Epicondylitis
- There is some overlap between these conditions, although it is not well understood
Comparison to Posterior Interosseous Nerve Syndrome
- Both syndromes involve compression of the PIN
- Radial tunnel syndrome: pain without motor or sensory
- PIN Syndrome: pain, motor weakness
Risk Factors
- Repetitive pronation-supination activities
- Female > Male
- Age 30s to 50s
Differential Diagnosis
Differential Diagnosis Forearm Pain
- Fractures
- Pediatric Specific Fractures
- Dislocations & Instability
- Soft Tissue Trauma
- Tendinopathies
- Neuropathies
- Pediatric Considerations
Differential Diagnosis Elbow Pain
- Fractures
- Adult
- Pediatric
- Dislocations & Instability
- Tendinopathies
- Bursopathies
- Ligament Injuries
- Neuropathies
- Arthropathies
- Other
- Pediatric Considerations
- Little League Elbow
- Panners Disease (Avascular Necrosis of the Capitellum)
- Nursemaids Elbow (Radial Head Subluxation)
Clinical Features
History
- Most commonly affects dominant arm
- Patients describe a deep, aching pain in the proximal dorsal-radial forearm
- Worse with lifting, pronation, supination
- Often worse at night
Physical Exam: Physical Exam Forearm
- Tender over 3-5 cm distal to lateral epicondyle
- Pain with resisted finger extension, wrist extension and supination
- Pain with passive pronation
- Typically no motor or sensory deficits
Special Tests
- Rule of Nine Test: Proposed special test to aid in diagnosis
- Resisted Active Forearm Extension Test: Active wrist extension against resistance
- Resisted Middle Finger Extension Test: Patient actively extends middle finger against resistance
Evaluation
Radiographs
- Standard Radiographs Elbow
- Screening imaging of choice, typically normal
MRI
- Usually negative but useful when considering other etiologies
- May help evaluate compressive sites, muscle changes (edema, atrophy), causes of entrapment
Ultrasound
- Diagnostic Radial Tunnel Injection
- Injection of anesthetic under ultrasound
- Positive if resolution of symptoms and pain, development of PIN palsy
EMG/NCS
- Often inconclusive
Classification
- N/A
Management
Nonoperative
- First line treatment
- Activity modification: avoid prolonged extension, pronation, wrist flexion
- Splinting
- NSAIDS
- Corticosteroid Injection
- Physical Therapy
Procedural
- Radial Tunnel Hydrodissection
- Injection can be considered diagnostic and therapeutic
Operative
- Indications
- Failure of nonoperative management at roughly 3 months
- Technique
- Radial tunnel release
Rehab and Return to Play
Rehabilitation
- Needs to be updated
Return to Play
- Needs to be updated
Prognosis and Complications
Prognosis
- Success rate of conservative management has been questioned
- Steven et al report only 4 out of 15 patients with the diagnosis of RTS had improvement with non-surgical treatments[5]
Complications
- Chronic pain
- Missed diagnosis
- Loss of ADLs
See Also
Internal
- Forearm Anatomy (Main)
- Forearm Pain (Main)
- Elbow Pain (Main)
- Wrist Pain (Main)
- Physical Exam Forearm
External
- Sports Med Review Elbow Pain: https://www.sportsmedreview.com/by-joint/elbow/
References
- ↑ Dang AC, Rodner CM. Unusual Compression Neuropathies of the Forearm, Part I: Radial Nerve. J Hand Surg Am. 2009;34(10):1906–14.
- ↑ Hazani, Ron, et al. "Anatomic landmarks for the radial tunnel." Eplasty 8 (2008): e37.
- ↑ Clavert P, Lutz JC, Adam P, Wolfram-Gabel R, Liverneaux P, Kahn JL. Frohse's arcade is not the exclusive compression site of the radial nerve in its tunnel. Orthop Traumatol Surg Res. 2009;95(2):114–8.
- ↑ Image courtesy of http://at.uwa.edu/, "wrist"
- ↑ Moss SH, Switzer HE. Radial tunnel syndrome: A spectrum of clinical presentations. J Hand Surg Am. 1983;8(4):414–20.
Created by:
John Kiel on 9 July 2019 23:37:42
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Last edited:
7 April 2025 16:20:14
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