Extensor Retinaculum

Extensor Retinaculum
Extensor Retinaculum
The extensor retinaculum is a thickening of deep fascia
that stretches across the back of the wrist and holds the
long extensor tendons in position (Figs. 9.56 and 9.57).
It converts the grooves on the posterior surface of the distal
ends of the radius and ulna into six separate tunnels for the
passage of the long extensor tendons. Each tunnel is lined
with a synovial sheath, which extends above and below the
retinaculum on the tendons. The tunnels are separated
from one another by fibrous septa that pass from the deep
surface
of the retinaculum to the bones.
The retinaculum is attached medially to the pisiform
bone and the hook of the hamate and laterally to the
distal
end of the radius. The upper and lower borders of the retinaculum
are continuous with the deep fascia of the
forearm and hand, respectively.
The contents of the tunnels beneath the extensor retinaculum
are described on page 397.