The hand and wrist have 27 bones organized into carpals, metacarpals, and phalanges. The wrist is a complex joint formed by 8 carpal bones with limited motion. Muscles are divided into intrinsic and extrinsic groups, with extrinsic muscles including wrist and digit flexors/extensors. Nerves include the median, ulnar, and radial nerves. The hand has a rich blood supply from the radial, ulnar, and deep palmar arches. Fascia including the flexor and extensor retinacula contain tendons. The hand's skin and pulley system enhance grasping.

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