2. The Wrist Complex
The wrist (carpus) consists of two compound joints:
The radiocarpal and the
midcarpal joints,
referred to collectively as the wrist complex
4. The shoulder serves as a dynamic base of support; the
elbow allows the hand to approach or extend away
from the body; and the forearm adjusts the approach
of the hand to an object.
The major contribution of the wrist complex seems to
be to control length-tension relationships in the multi
articular hand muscles and to allow fine adjustment of
grip.
5. The wrist has been called the most complex joint of
the body, from both an anatomic and physiologic
perspective.
The wrist complex as a whole is considered to be
biaxial, with motions of
extension/flexion around a coronal axis
ulnar deviation/radial deviation around an
anteroposterior axis.
6. Normal ranges are cited as
Wrist flexion, 65 to 85
extension 60 to85 ,
radial deviation 15 to 21
ulnar deviation 20 to 45
7. Radiocarpal Joint Structure
The radiocarpal joint is formed by the radius and
radioulnar disk as part of the triangular fibrocartilage
complex (TFCC) proximally and by the scaphoid,
lunate, and triquetrum distally
8. Triangular fibrocartilage
complex (TFCC)
The TFCC is essentially comprised of the
fibrocartilage disc interposed between the
medial proximal row and the distal ulna
within the medial aspect of the wrist
The primary function of the TFCC is to
improve joint congruency and to cushion
against compressive forces
The TFCC transmits about 20% of the axial load
from the hand to the forearm
9. Anatomy
The Wrist
Comprised of the distal radius and ulna,
eight carpal bones, and the bases of five
metacarpals
The carpal bones lie in two transverse rows
The proximal row contains (lateral to medial)
the scaphoid (navicular), lunate, triquetrum, and
pisiform
The distal row holds the trapezium, trapezoid,
capitate, and hamate
10. Anatomy
Mid Carpal Joints
The midcarpal joint lies between the two
rows of carpals
A ‘compound’ articulation because each
row has both a concave and convex
segment
The proximal row of the carpals is convex
laterally and concave medially.
The scaphoid, lunate, trapezium trapezoid, and
triquetrum present with a concave surface to
the distal row of carpals
11. Anatomy
Carpal Ligaments
The major ligaments of the wrist include the palmar
intrinsic ligaments, and the dorsal extrinsic and intrinsic
ligaments
The extrinsic palmar ligaments provide the majority of the
wrist stability
The intrinsic ligaments serve as rotational restraints, binding
the proximal row into a unit of rotational stability
12.
13.
14. Anatomy
Radiocarpal Joint
Formed by the large articular concave surface of the
distal end of the radius, the scaphoid and lunate of the
proximal carpal row, and the TFCC
15. Anatomy
Antebrachial Fascia
A dense connective tissue ‘bracelet’ that encases the
forearm and maintains the relationships of the tendons
that cross the wrist
16. Anatomy
The Extensor Retinaculum
This retinaculum serves to prevent the tendons
from ‘bow-stringing’ when the tendons turn a
corner at the wrist
17.
18. Anatomy
The extensor retinaculum compartments,
from lateral to medial, contain the
tendons of:
Abductor pollicis longus and extensor pollicis
brevis
Extensor carpi radialis longus and brevis
Extensor pollicis longus
Extensor digitorum and indicis
Extensor digiti minimi
Extensor carpi ulnaris
19. Anatomy
The Flexor Retinaculum
Transforms the carpal arch into a tunnel,
through which pass the median nerve and
some of the tendons of the hand
Proximally, the retinaculum attaches to the
tubercle of the scaphoid and the pisiform
Distally it attaches to the hook of the hamate, and
the tubercle of the trapezium
In the condition known as ‘carpal tunnel
syndrome’ the median nerve is compressed in
this relatively unyielding space
20. Anatomy
Carpal Tunnel
Serves as a conduit for the median nerve and
nine flexor tendons
The palmar radiocarpal ligament and the palmar
ligament complex form the floor of the canal
The roof of the tunnel is formed by the flexor
retinaculum (transverse carpal ligament)
The ulnar and radial borders are formed by carpal
bones (trapezium and hook of hamate
respectively)
Within the tunnel, the median nerve divides into a
motor branch and distal sensory branches
21. Anatomy
Tunnel of Guyon
A depression superficial to the flexor
retinaculum, located between the hook of the
hamate and the pisiform bones
The palmar (volar) carpal ligament, palmaris brevis
muscle, and the palmar aponeurosis form its roof
Its floor is formed by the flexor retinaculum
(transverse carpal ligament), pisohamate ligament,
and pisometacarpal ligament
The tunnel serves as a passage way for the
ulnar nerve and artery into the hand
22. Biomechanics
The wrist contains several segments whose combined
movements create a total range of motion that is
greater than the sum of its individual parts
23. Biomechanics
Pronation
Approximately 90° of forearm pronation is available
During pronation, the concave ulnar notch of the radius
glides around the peripheral surface of the relatively fixed
convex ulnar head
Pronation is limited by the bony impaction between the
radius and the ulna
24. Biomechanics
Supination
Approximately 85-90° of forearm supination is available
Supination is limited by the interosseous membrane, and
the bony impaction between the ulnar notch of the radius,
and the ulnar styloid process
25. Biomechanics
Wrist flexion and extension
The movements of flexion and extension of the wrist are
shared among the radiocarpal articulation, and the
intercarpal articulation, in varying proportions
26. Biomechanics
Wrist flexion and extension
During wrist flexion, most of the motion
occurs in the midcarpal joint (60% or 40°
versus 40% or 30° at the radiocarpal joint), and
is associated with slight ulnar deviation and
supination of the forearm
During wrist extension, most of the motion
occurs at the radiocarpal joint (66.5% or 40°
versus 33.5% or 20° at the midcarpal joint),
and is associated with slight radial deviation
and pronation of the forearm
27. Biomechanics
Radial Deviation
Radial deviation occurs primarily between the proximal
and distal rows of the carpal bones
The motion of radial deviation is limited by impact of the
scaphoid onto the radial styloid, and ulnar collateral
ligament
28. Biomechanics
Ulnar deviation
Ulnar deviation occurs primarily at the radiocarpal joint
Ulnar deviation is limited by the radial collateral ligament
34. Ganglion
Cystic structure that
arises from synovial
sheath
Discrete mass
Dull ache
Dorsal or Volar aspect
35. RANGE OF MOTION
Active range of motion
Passive range of motion if unable to actively move joint
Bliateral comparison
To determine degrees of restriction
36. RANGE OF MOTION
Wrist
Flexion
Extension
Radial deviation
Ulnar deviation
Ulnar deviation is
greater than radial
39. Scaphoid Fracture
Most commonly fractured carpal bone
70-80% of all carpal bone injuries
8% of all sports related fractures
1 in 100 college football players
Most susceptible to injury
Bridges proximal and distal rows of the carpal bones
Load to the dorsiflexed wrist as in fall onto outstretched hand
40. Scaphoid Fracture
Painful, swollen wrist after a fall
Tenderness in snuffbox
High frequency of nonunion and avascular necrosis
Initial x-rays often unremarkable
43. Scapholunate Dissociation
Diagnosis often missed
Pain, swelling, and decreased ROM
Pressure over scaphoid tuberosity elicits pain
Greatest pain over dorsal scapholunate area,
accentuated with dorsiflexion
X-ray shows widening of scapholunate joint space by
at least 3 mm
46. Triangular Fibrocartilage Complex
Injuries
Thickened pad of connective tissue that functions as a cushion
for the ulnar carpus as well as a sling support for the lunate and
triquetrum
Injury from compression between lunate and head of ulna
Breaking fall with hand
Rotational forces-racket and throwing sports
47. Triangular Fibrocartilage Complex
Injuries
Ulnar sided wrist pain,
swelling, loss of grip
strength
“Click” with ulnar
deviation
Point tenderness
distal to ulnar styloid
TFCC load test
48. Carpal Tunnel
Deep to palmaris
longus
Contains median
nerve and finger
flexor tendons
Most common
overuse injury of
the wrist
49. Carpal Tunnel Syndrome
Entrapment of the median nerve
Phalen’s and Tinel’s Test
2 point discrimination
Symptoms
Aching in hand and arm
Nocturnal or AM paresthesias
“Shaking” to obtain relief
50. Carpal Tunnel Tests
Neurologic exam
Median nerve
sensation and motor
Phalen’s Test:
both wrists maximally
flexed for 1 minute
Tinel’s Test