anatomy upper limb

1. Flexor & Extensor
retinaculum of the hand
Dr M Idris Siddiqui

2. Flexor Retinaculum
(Transverse carpal ligaments)
• Thick connective tissue which forms the roof
of the carpal tunnel.
• Turns the carpal arch into the carpal tunnel by
bridging the space between the medial and
lateral parts of the arch.
• Originates on the lateral side and inserts on
the medial side of the carpal arch.
• Laterally: split into two laminae; the superficiala & Deep lamina:
(The tendon of flexor carpi radialis lies between the 2 lamina).

3. The flexor retinaculum
The flexor retinaculum is a strong fibrous
band, measuring 2–3 cm transversely and
longitudinally, which lies across the front
of the carpus at the proximal part of the
hand.
• Its proximal limit lies at the level of the
distal, dominant skin crease on the front
of the wrist.

8. The Carpal Tunnel
• The Carpal Tunnel is located at the wrist and is
anteriorly composed by a deep arch.
• Carpal tunnel is an important site because major
neurological, circulatory, skeletal structures pass
through it.
• As the hand plays important function in everyday life,
the importance of carpal tunnel increases significantly
in anatomical studies.

13. The carpal tunnel
• The median nerve is anterior to the tendons in the
carpal tunnel. With the exception of the tendon of
the flexor pollicis longus, all the tendons of the flexor
digitorum profundus as well as flexor digitorum
superficialis are incorporated by simply one synovial
sheath: a various sheath encompasses the tendon of
the flexor pollicis longus.
• The tendon of the flexor carpi radialis is covered by a
synovial sheath and undergoes a tubular area produced
by the attachment of the lateral element of the flexor
retinaculum to the margins of a groove on the medial
aspect of the tubercle of the trapezium.

15. The carpal tunnel
• The ulnar artery, ulnar nerve, and
tendon of the palmaris longus do not
pass through the carpal tunnel and
therefore go into the hand anterior to the
flexor retinaculum in carpal tunnel.
• The tendon of the palmaris longus isn’t
enveloped by a synovial sheath.

17. Contents of carpal tunnel
• A total of 9 tendons, surrounded by synovial
sheaths.
– The 4 tendons of the flexor digitorum profundus
– The 4 tendons of the flexor digitorum superficialis
– The tendon of the flexor pollicis longus surrounded by
its own synovial sheath.
• The median nerve.
– The palmar cutaneous branch of the median nerve is
given off prior to the carpal tunnel, travelling
superficially to the flexor retinaculum.
• Sometimes the carpal tunnel contains another tendon, the flexor carpi radialis tendon.
– But this is located within the flexor retinaculum and not within the carpal tunnel itself.
surrounded by
a single
synovial
sheath

19. Structures on the Anterior Aspect of the Wrist
Superficial to the flexor retinaculum from medial to lateral
Flexor carpi ulnaris tendon ending on the pisiform bone. (This tendon does
not actually cross the flexor retinaculum but is
included for the sake of completeness)
Ulnar nerve lies lateral to the pisiform bone.
Ulnar artery lies lateral to the ulnar nerve.
Palmar cutaneous branch of the
ulnar nerve
Palmaris longus tendon (if
present)
passing to its insertion into the flexor retinaculum
and the palmar aponeurosis
Palmar cutaneous branch of the
median nerve

20. Structures on the Anterior Aspect of the Wrist
Deep to the flexor retinaculum from medial to lateral
Flexor digitorum superficialis
tendons & posterior to these, the
tendons of the flexor digitorum
profundus
both groups of tendons share a
common synovial sheath
Median nerve
Flexor pollicis longus tendon surrounded by a synovial sheath
Flexor carpi radialis tendon going
through a split in the flexor
retinaculum.
The tendon is surrounded by a
synovial sheath.

21. Extensor retinaculum
Its proximal attachment is to the anterolateral border
of the radius above the styloid process.
It is not attached to the ulna; its distal attachment is
to The Pisiform and triquetral bones.

23. Extensor retinaculum
From the deep surface of the
extensor retinaculum fibrous
septa pass to the bones of the
forearm, dividing the extensor
tunnel into six compartments.

25. Extensor retinaculum
1. The most lateral compartment lies over the
lateral surface of the radius at its distal extremity,
and through it pass the tendons of abductor
pollicis longus and extensor pollicis brevis, each
usually lying in a separate synovial sheath.
2. The next compartment extends as far as the
dorsal tubercle, and conveys the tendons of the
radial extensors of the wrist (longus and brevis),
each lying in a separate synovial sheath.

26. Extensor retinaculum
3. The groove on the ulnar side of the radial tubercle lodges
the tendon of extensor pollicis longus, which lies within its
own compartment invested with a synovial sheath.
4. Between this groove and the ulnar border of the radius is a
shallow depression in which all four tendons of extensor
digitorum lie, crowded together over the tendon of extensor
indicis. All five tendons in this compartment are invested
with a common synovial sheath.
5. The next compartment lies over the radioulnar joint and
transmits the tendon of extensor digiti minimi in a synovial
sheath.
6. Lastly, the groove near the base of the ulnar styloid
transmits the tendon of extensor carpi ulnaris in its synovial
sheath.

28. Extensor retinaculum

31. Structures on the Posterior Aspect of
the Wrist
Superficial to the extensor retinaculum from medial to lateral
Dorsal (posterior) cutaneous branch of the
ulnar nerve
Basilic vein
Cephalic vein
Superficial branch of the radial nerve

32. Structures on the Posterior Aspect of the Wrist
Deep to the extensor retinaculum from medial to lateral
Extensor carpi ulnaris tendon grooves the posterior aspect of the head of the
ulna
Extensor carpi ulnaris tendon grooves the posterior aspect of the head of the
ulna
Extensor carpi ulnaris tendon grooves the posterior aspect of the head of the
ulna
Extensor pollicis longus tendon winds around the medial side of the dorsal
tubercle of the radius.
Extensor carpi radialis longus
and brevis tendons
share a common synovial sheath and are situated
on the lateral part of the posterior surface of the
radius.
Abductor pollicis longus and the
extensor pollicis brevis tendons
have separate synovial sheaths but share a
common compartment.