a to z of wrist complex by usman
TRANSCRIPT
The Wrist ComplexPRESENTED BY : USMAN FAROOQ
The Wrist Complex
The wrist (carpus) consists of two compound joints:
The radiocarpal and the
midcarpal joints,
referred to collectively as the wrist complex
Wrist Complex
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.
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.
Normal ranges are cited as
Wrist flexion, 65 to 85
extension 60 to85 ,
radial deviation 15 to 21
ulnar deviation 20 to 45
Radiocarpal Joint Structure
The radiocarpal joint is formed by the radius and radioulnar disk as part of the triangular fibrocartilagecomplex (TFCC) proximally and by the scaphoid, lunate, and triquetrum distally
Triangular fibrocartilagecomplex (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
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
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
Anatomy
Carpal Ligaments
The major ligaments of the wrist include the palmarintrinsic 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
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
Anatomy
Antebrachial Fascia
A dense connective tissue ‘bracelet’ that encases the forearm and maintains the relationships of the tendons that cross the wrist
Anatomy
The Extensor Retinaculum
This retinaculum serves to prevent the tendons from ‘bow-stringing’ when the tendons turn a corner at the wrist
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
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
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
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 brevismuscle, 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
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
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
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
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
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
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
Biomechanics
Ulnar deviation
Ulnar deviation occurs primarily at the radiocarpal joint
Ulnar deviation is limited by the radial collateral ligament
Clinical Examinationof the
Wrist Joint
HISTORY
Age
Chief complaint
Occupation
Previous injury
Previous surgery
What exacerbates
What improves
Frequency
Duration
HISTORY
4 principle mechanisms of injury
Throwing
Weight bearing
Twisting
Impact
PHYSICAL EXAM
Inspection
Palpation
Range of Motion
Neurologic Exam
Special Tests
Ganglion
Cystic structure that arises from synovial sheath
Discrete mass
Dull ache
Dorsal or Volar aspect
RANGE OF MOTION
Active range of motion
Passive range of motion if unable to actively move joint
Bliateral comparison
To determine degrees of restriction
RANGE OF MOTIONWrist
Flexion
Extension
Radial deviation
Ulnar deviation
Ulnar deviation is greater than radial
PALPATION of Wrist Dorsum
Radial Styloid
Scaphoid
1st MC/Trapezium jt
Lunate
Lister’s Tubercle
Ulnar Styloid
TFCC
Triquetrum
Pisiform
Hook of Hamate
Guyon’s Tunnel
Radial Styloid palpation Scaphoid Bone palpation
Radial styloid
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
Scaphoid Fracture
Painful, swollen wrist after a fall
Tenderness in snuffbox
High frequency of nonunion and avascular necrosis
Initial x-rays often unremarkable
1st MC/Trapezium joint palpation
Lunate Bone palpation
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
Ulnar Styloid palpationLister’s Tubercle palpation
Ulnar styloid
Triangular Fibro-Cartilage Complex palpation (TFCC)
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
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
Carpal Tunnel
Deep to palmaris longus
Contains median nerve and finger flexor tendons
Most common overuse injury of the wrist
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
Carpal Tunnel Tests
Neurologic exam
Median nerve sensation and motor
Phalen’s Test:both wrists maximally flexed for 1 minute
Tinel’s Test
NEUROLOGIC EXAM
Muscular assessment using grading system
Sensation testing
Bilateral comparison
NEUROLOGIC EXAMMuscle Testing
WRIST
EXT C6
FLEX C7
FINGERS
EXT C7
FLEX C8
ABD T1
ADD T1
Sensation TestingDorsal hand Radial hand