Home › Body Atlas › Fascia & Spaces › Extensor Retinaculum Second Compartment Septum

Fascia or Space Hand & Wrist

Extensor Retinaculum Second Compartment Septum

septum compartimenti extensorii secundi

The second dorsal extensor compartment is the fibro-osseous tunnel under the extensor retinaculum that carries the extensor carpi radialis longus and brevis tendons over the distal radius, just radial to Lister tubercle. A few centimetres above it, the first compartment muscles cross over these tendons, which is the site of intersection syndrome; when rest and injection fail, release of the second compartment is the usual surgery.

Anatomical Data

Boundaries & Contents

Location	Dorsal wrist, over the distal radius on the radial side of Lister tubercle
Boundaries	Floor: dorsal surface of the distal radius radial to Lister tubercle Roof: extensor retinaculum Septa of the retinaculum separate it from the first compartment radially and the third ulnarly
Contents	Extensor carpi radialis longus tendon Extensor carpi radialis brevis tendon Their synovial sheath

Biomechanics

Function & Actions

Holds the radial wrist extensor tendons against the radius so they do not bowstring when the wrist extends.

Clinical Relevance

Clinical Notes

The retinacular septa dividing the extensor compartments are the key structures in compartment-specific wrist surgery. Inadvertent extension of first compartment release into the second compartment may produce ECRL/ECRB subluxation. Proper identification of the septa prevents over-release in de Quervain surgery.

Pathology

Common Injuries & Conditions

Second Compartment Intersection Syndrome

Friction bursitis between the first and second extensor compartments at the proximal wrist producing pain and crepitus with thumb movement 4-6 cm proximal to Lister's tubercle, managed with injection and activity modification.

Explore

More in Hand & Wrist

Browse all of Hand & Wrist →