Radial Tunnel Syndrome
   HOME

TheInfoList



OR:

Radial tunnel syndrome (RTS) is caused by increased pressure on the radial nerve as it travels from the upper arm (the
brachial plexus The brachial plexus is a network () of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve ( C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in th ...
) to the hand and wrist.


Symptoms and signs

Radial tunnel syndrome causes posterolateral elbow pain that is similar to
tennis elbow Tennis elbow, also known as lateral epicondylitis or enthesopathy of the extensor carpi radialis origin, is a condition in which the outer part of the elbow becomes painful and tender. The pain may also extend into the back of the forearm. Onset ...
and may sometimes occur in conjunction with that condition. Patients may typically have weakness of extension at the wrist and third digit. The pain is often reproduced upon resisted supination of the forearm, and pain at the radial tunnel on resisted hyperextension of the wrist.


Cause

The theory is that the
radial nerve The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial comp ...
becomes irritated and/or inflamed from friction caused by compression by muscles in the
forearm The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in anat ...
. Some speculate that radial tunnel syndrome is a type of
repetitive strain injury A repetitive strain injury (RSI) is an injury to part of the musculoskeletal or nervous system caused by repetitive use, vibrations, compression or long periods in a fixed position. Other common names include repetitive stress disorders, cumula ...
(RSI), but there is no detectable pathophysiology and even the existence of this disorder is questioned. The term "radial tunnel syndrome" is used for compression of the
posterior interosseous nerve The posterior interosseous nerve (or dorsal interosseous nerve) is a nerve in the forearm. It is the continuation of the deep branch of the radial nerve, after this has crossed the supinator muscle. It is considerably diminished in size compared ...
, a division of the radial nerve, at the
lateral intermuscular septum of arm The fascial compartments of arm refers to the specific anatomical term of the compartments within the upper segment of the upper limb (the arm) of the body. The upper limb is divided into two segments, the arm and the forearm. Each of these seg ...
, while "supinator syndrome" is used for compression at the arcade of Frohse. The "radial tunnel" is the region from the humeroradial joint past the proximal origin of the supinator muscle. Some scientists believe the radial tunnel extends as far as the distal border of the supinator. The radial nerve is commonly compressed within a 5 cm region near the elbow, but it can be compressed anywhere along the forearm if the syndrome is caused by injury (e.g. a fracture that puts pressure on the radial nerve). The radial nerve provides sensation to the skin of posterior arm, posterior and lateral forearm and wrist, and the joints of the elbow, wrist and hand. The nerve also provides sensory branches that travel to the periosteum of the lateral epicondyle, the anterior radiohumeral joint, and the annular ligament. It provides motor function through innervation to most extensor muscles of the posterior arm and forearm. Therefore, it is extremely important in upper body extremity movement and can cause significant pain to patients presenting with radial tunnel syndrome. Unlike
carpal tunnel syndrome Carpal tunnel syndrome (CTS) is the collection of symptoms and signs associated with median neuropathy at the carpal tunnel. Most CTS is related to idiopathic compression of the median nerve as it travels through the wrist at the carpal tunn ...
, radial tunnel syndrome does not present tingling or numbness, since the posterior interosseous nerve mainly affects motor function. This problem is often caused by: bone tumors, injury (specifically fractures of the forearm), noncancerous fatty tumors (lipomas), and inflammation of surrounding tissue.


Diagnosis

The diagnosis is based on symptoms and signs alone and objective testing is expected to be normal. This syndrome may be clinically tested by flexing the patients long finger while the patient extends the wrist and fingers. Pain is a positive finding. The chief complaint of this disease is usually pain in the dorsal aspect of the upper forearm, and any weakness described is secondary to the pain. Tenderness to palpation occurs over the area of the radial neck. Also, the disease can be diagnosed by a positive "middle finger test", where resisted middle finger extension produces pain. Radiographic evaluation of the elbow should be performed to rule out other diagnoses.


Treatment

Non-surgical treatment of radial tunnel syndrome includes rest,
NSAID Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...
, therapy with modalities, work modification, ergonomic modification, injection if associated with
lateral epicondylitis Tennis elbow, also known as lateral epicondylitis or enthesopathy of the extensor carpi radialis origin, is a condition in which the outer part of the elbow becomes painful and tender. The pain may also extend into the back of the forearm. Onset ...
. Patients whose conditions are more adapted to surgical intervention are those who do not respond to prolonged conservative treatment. The patient must have pain with resisted supination, positive middle finger test, positive electrodiagnostic findings, and pain relief after anesthetic injection into the radial tunnel. Based on 2002 data, surgical decompression leads to 60–70% good or excellent results.


See also

*
Golfer's elbow Golfer's elbow, or medial epicondylitis, is tendinosis of the medial epicondyle on the inside of the elbow. It is in some ways similar to tennis elbow, which affects the outside at the lateral epicondyle. The anterior forearm contains several m ...
*
Repetitive strain injury A repetitive strain injury (RSI) is an injury to part of the musculoskeletal or nervous system caused by repetitive use, vibrations, compression or long periods in a fixed position. Other common names include repetitive stress disorders, cumula ...
*
Tennis elbow Tennis elbow, also known as lateral epicondylitis or enthesopathy of the extensor carpi radialis origin, is a condition in which the outer part of the elbow becomes painful and tender. The pain may also extend into the back of the forearm. Onset ...


References


Further reading


Books

* * * *


Journals

* * * * * * * * * * *


External links

{{PNS diseases of the nervous system Musculoskeletal disorders Occupational diseases Overuse injuries Syndromes