Extensor tendons are divided into six different compartments discussed below.
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
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.
Transverse retinacular ligaments will prevent dorsal subluxation of lateral bands and triangular ligaments will prevent volar subluxation of lateral bands
Compartments of Extensor tendons
| Compartment | Structures |
|---|---|
| 1st Compartment | Abductor pollices longus (APL) and extensor pollices brevis (EPB) |
| 2nd Compartment | Extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB) |
| 3rd Compartment | Extensor pollices longus (EPL) |
| 4th Compartment | Extensor indices proprious (EIP), Extensor digitorium communis (EDC), posterior interosseous nerve (PIN) |
| 5th Compartment | Extensor digiti minimi (EDM) |
| 6th Compartment | Extensor carpi ulnaris (ECU) |
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
