April 11, 2024

Extensor tendons are divided into six different compartments discussed below.

Extensor Tendons visualized from skin
Extensor Tendon visualized from skin

The Extensor retinaculum will prevent tendon bowstringing at the wrist

Sagittal bands will aid in metacarpophalangeal(MCP) joint extension, and attach to the volar plate

Central slip will insert on the base of the middle phalanx and aid in proximal interphalangeal joint extension

Extensor tendon anatomy
Extensor tendon Anatomy

Interossei and lumbricals will provide a contribution to the extensor mechanisms and lateral bands will receive contributions from common extensor and intrinsic, converge to form terminal extensor tendons, which inserts on the base of the distal phalanx.

Extensor tendon anatomy
Extensor tendon anatomy

Transverse retinacular ligaments will prevent dorsal subluxation of lateral bands and triangular ligaments will prevent volar subluxation of lateral bands

Compartments of Extensor tendons

1st CompartmentAbductor pollices longus (APL) and extensor pollices brevis (EPB)
2nd CompartmentExtensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB)
3rd CompartmentExtensor pollices longus (EPL)
4th CompartmentExtensor indices proprious (EIP), Extensor digitorium communis (EDC), posterior interosseous nerve (PIN)
5th CompartmentExtensor digiti minimi (EDM)
6th CompartmentExtensor carpi ulnaris (ECU)
Compartments of Extensor tendons

Grayson (Ground: Volar) ligaments and Cleland (Ceiling: Dorsal) ligaments are volar and dorsal to digital neurovascular bundles, respectively.

Oblique retinacular ligaments (Ligament of Landsmeer) will help to link PIP and DIP joint extension

See also: Flexor Tendon Injury

See also: Blood Supply of hand