The dorsal extensor retinaculum is a broad fibrous band approximately 2-3 cm wide crossing the dorsal wrist from the lateral radius to the triquetrum and pisiform medially. Vertical septa from its deep surface divide it into six compartments, each containing one or more extensor tendon groups. The six compartments contain, from radial to ulnar: APL and EPB (first), ECRL and ECRB (second), EPL (third), EI and EDC (fourth), EDM (fifth), and ECU (sixth).
Holds the dorsal wrist extensor tendons against the bones during wrist and finger extension, preventing bowstringing, and maintains each tendon in its compartment, ensuring independent function and efficient force transmission.
The dorsal extensor retinaculum defines the six wrist extensor compartments and is the structure divided in de Quervain release (first compartment) and extensor carpi ulnaris sheath repair (sixth compartment). EPL rupture after distal radius fracture occurs from attrition in the third compartment groove around Lister tubercle. Dorsal wrist ganglia arise from the scapholunate joint beneath the retinaculum. Extensor tenosynovitis from rheumatoid arthritis causes retinacular thickening and compartment stenosis requiring surgical synovectomy and retinacular release.
Stenosis of the first extensor compartment beneath the dorsal retinaculum around the radial styloid process causes APL and EPB tendon friction, producing lateral wrist pain with a positive Finkelstein test, managed with injection and surgical first compartment release when conservative measures fail.
Friction between the second extensor compartment tendons (ECRL, ECRB) and the first compartment tendons (APL, EPB) crossing over each other approximately 4-6 cm proximal to the wrist causes painful crepitus at the intersection point, managed with splinting, injection, and occasionally surgical release of the second compartment retinaculum.
