Stemcelldoc's Weblog

September 27, 2012

Intersection Syndrome: A cause of forearm pain

At the Centeno-Schultz Clinic we acknowledge that forearm pain can be disabling.

Intersection syndrome is a painful condition on the radial (thumb) side of the forearm when inflammation occurs at the intersection of the first and second extensor tendons. 

The first compartment is compromised of EPB (extensor pollicis brevis) and APL (abductor pollicis longus) whereas the second compartment includes ECRB and ECRL (extensor carpi radialis brevis and longus).

Presentation:  pain approximately 4 cm above the back of the wrist joint where the first and second compartment tendons cross.


Tendons are surrounded by a slippery sac called a tenosynovium which allows the tendons to glide.  Inflammation of the tenosynovium (tenosynovitis) impairs the tendons ability to glide and results in pain.

Etiology can be traumatic or due to repetitive wrist flexion and extension commonly seen in weightlifters ad rowers.

 Other causes of radial forearm pain include de Quervain tenosynovitis, thumb CMC arthritis, radial sensory nerve irritation and extensor pollicis longus (EPL) tendinitis.

In cases unresponsive to conservative therapy a guided injection under ultrasound is indicated.  At the Centeno-Schultz Clinic MSK US is utilized in joint, ligament and tendon injections.  Accuracy and visualization is critical for successful clinical results.  Below is an ultrasound image of the first and second compartment tendons crossing.  The white arrows identify the tendons of compartment 1 superficially crossing those of compartment 2.  This is the site of inflammation in intersection syndrome that results in radial side forearm pain.

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