Intersection syndrome is a repetitive motion injury of the wrist that occurs from overuse and subsequent inflammation, or peritenosynovitis, at the intersection of the muscles of the first and second dorsal compartments. The muscles involved in this syndrome are the abductor pollicis longus (APL) and the extensor pollicis brevis (EPB) of the first dorsal compartment and the extensor carpi radialis brevis (ECRB) and extensor carpi radialis longus (ECRL), or radial wrist extensors, of the second dorsal compartment. Fluid collection in the tendon sheaths of these muscles along with swelling and pain are indications of this syndrome. Intersection syndrome is fairly uncommon and is usually a result of recurring flexion and extension of the wrist.
Pathophysiology
Repetitive flexion and extension of the wrist, often associated with resistance, is the major cause of intersection syndrome. It commonly occurs in rowers, weightlifters, gymnasts, and athletes participating in sports that require swinging a racquet, stick, or bat (eg, tennis, field hockey, or baseball). Additionally, manual laborers who undergo extensive and repetitive flexing and extending motions with high resistance and compression forces can develop intersection syndrome (eg, landscapers).
Related Anatomy
Dorsal compartments 1 and 2 are involved in intersection syndrome; there are six dorsal compartments involved in wrist movement.
Incidence and Related Conditions
- Occurs in 0.2–0.4% of the general population
- Possibly a greater incidence occurs among athletes, but this has yet to be studied
- Intersection syndrome can be mistaken for other syndromes, and there is controversy regarding the exact location of the tendons causing the condition (compartment 2 or both 1 and 2)
Differential Diagnosis
- Blunt trauma
- de Quervain’s tenosynovitis (dorsal compartment 1)
- Ganglion cysts
- Muscle strains
- Tenosynovitis (dorsal compartments 2 or 3)
- Wartenberg’s syndrome
- Wrist ligament strains
