1. Wrist and Hand Anatomy
Moderator: Dr. Asif Sultan
Presented by: Qazi Manaan

2. Overview
• The anatomy of the hand is complex, intricate,
and fascinating.
• Absolutely essential for our everyday functional
living.

3. Bone Anatomy
• Total of 27 bones in hand and wrist.
• These are grouped into carpals, metacarpals,
and phalanges.
• The wrist is the most complex joint in the body. It is
formed by 8 carpal bones grouped in 2 rows with very
restricted motion between them.

5. • All carpal bones participate in wrist function
o except for the pisiform.
• The scaphoid serves as link between each row;
therefore, it is vulnerable to fractures.
• The distal row of carpal bones is strongly attached
to the base of the second and third metacarpals,
forming a fixed unit.

6. • The hand contains 5 metacarpal bone.
• First Metacarpal articulates proximally with the
trapezium.
• The other 4 metacarpals articulate with the
trapezoid, capitate, and hamate at the base.
• The hand contains 14 phalanges.

8. JOINTS

9. • All 4 distal carpal bones articulate with the
metacarpals at the carpometacarpal (CMC) joints.
• At the metacarpophalangeal joints, lateral motion is
limited by the collateral ligaments

10. • At the CMC joint, the volar plate is part of the joint
capsule that attaches only to the proximal phalanx,
allowing hyperextension.
• At the interphalangeal joints:
 extension is limited by the volar plate, which attaches
to the phalanges at each side of the joint.
 Radial and ulnar motion is restricted by collateral
ligaments.

12. Muscles and Tendons

13. • The muscles of the hand are divided into:
Intrinsic and
Extrinsic group.

14. Extrinsic extensors
• All extensors are extrinsic and supplied by radial
nerve.
• Except for the interosseous-lumbrical complex.
• Group contains:
3 wrist extensors
A larger group of thumb and digit extensors.

15. • The main extensors at wrist are:
 The extensor carpi radialis brevis (ECRB)
 extensor carpi radialis longus (ECRL)
 extensor carpi ulnaris (ECU)

16. • At the digits, extension occurs due to:
The extensor digitorum communis,
extensor indicis proprius, and
extensor digiti minimi

17. • Extension at the thumb is bought about by:
The abductor pollicis longus,
extensor pollicis brevis, and
extensor pollicis longus

18. Extrinsic Flexors
• 3 wrist flexors
• A larger group of thumb and digit flexors
• Innervated by the median nerve
• Except for the FCU, and the FDP to the small and ring
finger, which are innervated by the ulnar nerve.

19. • The main Flexors at the wrist joint are:
 The flexor carpi radialis
 the flexor carpi ulnaris and
 the palmaris longus

20. • The digital flexors include:
Flexor Digitorum Superficialis
Flexor Digitorum Profundus
Flexor Pollicis Longus

21. Intrinsics
• Situated totally within the hand
• Divided into 4 groups:
the thenar,
hypothenar,
lumbrical, and
interossei muscles.

22. • The thenar group
consists of:
 the abductor pollicis
brevis,
 flexor pollicis brevis,
 opponens pollicis, and
 adductor pollicis
muscles.

23. • The hypothenar group
consists of:
 the palmaris brevis,
 abductor digiti minimi,
 flexor digiti minimi, and
 opponens digiti minimi.

24. • The lumbrical muscles
contribute to
 the flexion of the MCP
joints and
 extension of the
interphalangeal joints.

25. • The interossei group
consists of:
 3 palmar and
 4 dorsal muscles
• All innervated by the
ulnar nerve.

26. Zones of the Hand

27. Flexor Zones

28. Extensor Zones

29. NERVES
• 3 nerves:
 Median
 Ulnar
 Radial

30. Median nerve
• Crucial in the gripping mechanism by the thumb.
• It originates from the lateral and medial cords of the brachial
plexus (C5-T1).
• In the forearm, the motor branches supply the pronator teres,
flexor carpi radialis, palmaris longus, and flexor digitorum
superficialis muscles.
• The anterior interosseus branch innervates the flexor pollicis
longus, flexor digitorum profundus (radial part), and pronator
quadratus muscles.

31. • Palmar cutaneous branch provides sensation at the
thenar eminence. Also sensory digital branches
provide sensation to the radial three and a half
fingers and corresponding palm area
• As the median nerve passes through the carpal
tunnel, the recurrent motor branch innervates the
thenar muscles
• It also innervates the index and middle finger
lumbrical muscles

33. Signs of a Lesion:
• Benediction Sign :

34. • Ape Thumb Deformity:

35. • Median Claw Hand:

36. Pen Test

37. Ulnar nerve
• Controls fine movement of the fingers
• It originates at the medial cord of the
brachial plexus (C8-T1)
• Sensory to the:
hypothenar eminence
The palmar and dorsal ulnar one and a
half fingers

38. • The deep motor branch passes through the Guyon canal in
company with the ulnar artery. It innervates the
 hypothenar muscles
 all interossei,
 the 2 ulnar lumbricals,
 the adductor pollicis, and
 the deep head of the flexor pollicis brevis

39. Signs of a lesion:
• Ulnar Claw Hand:

40. Froment’s Sign

41. Egawas’ Test

42. Card Test

43. Radial nerve
• Innervates the wrist extensors.
• Originates from the posterior cord of the brachial
plexus (C6-8).
• At the elbow, motor branches innervate the
brachioradialis and extensor carpi radialis longus
muscles.

44. • At the proximal forearm, the radial nerve divides into
the superficial and deep branches.
• The deep posterior interosseous branch innervates all
the muscles in the extensor compartment.
• The superficial branch provides sensation at the radial
aspect of the dorsum of the hand, the dorsum of the
thumb, and the dorsum of the radial three and a half
digits proximal to the distal interphalangeal joints.

45. Signs of a lesion
• Wrist Drop

46. • Loss of Supination:

47. Blood Supply
• Complex and rich vascular network

48. Radial Artery
• Course
• A superficial branch arises at the level of the wrist and
contributes to the superficial palmar arch.
• In the palm it gives off:
 Princeps pollicis artery and
 Radialis Indicis artery, before terminating in the deep
palmar arch.

50. Ulnar Artery
• It travels into the hand through the Guyon
canal, where it divides into:
• the deep palmar branch and
• the superficial palmar branch.

51. Superficial Palmar Arch
• Lies directly deep to the palmar fascia.
• It gives rise to the:
 volar common digital arteries and
 multiple branches to intrinsic muscles and skin.
• Distally,the common digital arteries bifurcate into the
proper digital arteries.

52. Deep Palmar Arch
• Lies at the base of the metacarpals, deep to
the flexor tendons.
• From its convexity it gives off three
palmar metacarpal arteries.
• Dorsally it gives off three perforating
arteries.
• Recurrent branches arise from the
concavity to supply the carpal bones

53. Dorsal Carpal Arch
• Formed by:
 the posterior interosseous artery and
 a dorsal perforating branch of the anterior interosseous
artery.
• Dorsal metacarpal arteries arise from a dorsal carpal
arch

54. MODIFIED ALLEN TEST

55. Veins
• Veins generally follow
the deep arterial system
as venae comitantes.
• A superficial venous
system also exists at the
dorsum of the hand
and contributes to the
cephalic and basilic
veins in the upper
extremity.

56. Deep Fascia
• The Flexor Retinaculum
• The Palmar Fascia
• Fibrous flexor sheaths in fingers
• The Extensor Retinaculum

57. • FLEXOR RETINACULUM

58. • The Palmar fascia consists of resistant fibrous
tissue arranged in longitudinal, transverse,
oblique, and vertical fibers.
• The transverse fibers are concentrated in the
mid palm and web spaces and serve as pulleys
for the flexor tendons proximal to the digital
pulleys.

59. •The digits contain 2 fascial
bands of clinical importance:
the Grayson ligament and
the Cleland ligament

60. Pulley
• The pulley system is critical to flexion of the finger.
• The retinacular system for each of the fingers contains 5
annular pulleys and 3 cruciate pulleys.

61. • The thumb has 2 annular pulleys and 1
oblique pulley.
• The system supplies mechanical advantage
by maintaining the flexor tendons close to
the joint's axis of motion. In doing so, the
pulleys prevent bowstringing.
.

62. Extensor Retinaculum and the 6 compartments

63. Compartments of the Hand
• 10 separate osteofascial
compartments:
- dorsal interossei (4
compartments)
- palmar interossei (3
compartments)
- adductor pollicis
- thenar and hypothenar
• Typically can be released with
carpal tunnel release and 2
dorsal incisions

65. SKIN

66. • The skin of the dorsum of the
hand is thin and pliable.
• It is attached to the hand's
skeleton only by loose areolar
tissue, where lymphatics and
veins course.
• explains why edema of the
hand is manifested
predominantly at the dorsum.

67. • The skin of the palmar surface of the hand is
unique
Thick
Glabrous
Less Pliable
• This enhances skin stability for proper grasping
function.

68. • The skin is most firmly anchored to the deep
structures at the palmar creases.
• Blood supply is through numerous small, vertical
branches from the common digital vessels.
• High concentration of sensory nerve organs
essential to the hand's normal function.

69. Thank You