Intersection syndrome is a painful tenosynovitis involving
the tendons of the extensor carpi radialis longus and extensor carpi radialis
brevis. There are six extensor compartments of the wrist. The pathology occurs
due to stenosis of the second dorsal wrist compartment. The intersection
syndrome is an overuse injury caused by repetitive wrist extension with
pronation and supination. Intersection syndrome can occur in weight lifting,
rowing, and in racket sports. The area of pain and tenderness is located at the
intersection between the muscles of the abductor pollicis longus and extensor
pollicis brevis, as these two muscles cross over the tendons of the extensor
carpi radialis longus and brevis. The patient may describe a squeaking
sensation with wrist motion. This intersection syndrome is sometimes called the
squeakers wrist or the cross over tendonitis. When the first and second dorsal
wrist compartments pass over each other, it will result in inflammation, muscle
changes, fibrous and squeaking during wrist motion. These findings along with
the site and location of the pain over the dorsal forearm and wrist, which is
about 5 cm distal to the wrist joint, helps to differentiate De Quervain’s
Syndrome from intersection syndrome. When the first dorsal wrist compartment
tendons cross over the second compartment structures, the tenderness is
palpated at the dorsoradial forearm, approximately 5 cm proximal to the wrist
joint. The pain gets worse with resisted wrist extension and the x-ray will not
show you anything. You will feel crepitus over the area with resisted wrist
extension and thumb extension. MRI will probably show you edema or fluid
surrounding the first and the second extensor compartments. To treat
intersection syndrome, rest, do wrist splinting, and perhaps a steroid
injection. Try to inject the second dorsal compartment; ultrasound guided
injection may be helpful. Surgery is done as a last resort. Release the second
dorsal compartment about 5-6cm proximal to the wrist joint.
