Hand And Wrist Flashcards
How do scaphoid fractures occur?
Fall onto outstretched hand
Hyperextension and impact of scaphoid into rim of radius
What are the symptoms of a scaphoid fracture?
Pain in anatomical snuffbox
Exacerbated by moving wrist
Passive range motion reduced
Why may a scaphoid fracture have delayed diagnosis?
Not clear initially
Becomes visually when bone reabsorption starts to occur
What are common complications of scaphoid fractures?
Avascular necrosis (if fracture at waist of bone due to retrograde blood supply) Malunion Non-union
What is a Colles’ fracture?
Extra-articular fracture of distal radial metaphysics with dorsal angulation and impaction
Looks like upturned fork
What is the mechanism of Colles’ fractures?
Fall onto outstretched hand with pronated forearm
Wrist is dorsiflexed
Energy transmitted from carpus to distal radius in dorsal direction
What are complications of Colles’ fractures?
Malunion (dinner fork deformity)
Median nerve palsy
Secondary OA
Tear in extensor pollcis longus tendon
What is a Smith fracture?
Fracture of distal radius with palmar angulation of distal fragment
What is the mechanism of a Smith fracture?
Fall onto dorsal of flexed wrist
Direct blow to back of wrist
What is a complication of a Smith fracture?
Malunion = garden spade deformity
What joints in the hand are normally affected by rheumatoid arthritis?
MCPJ
PIPJ
How does RhA present in the hands?
Pain and swelling of effected joint Redness Stiffness Carpal tunnel syndrome (due to swelling) Flu symptoms Rheumatoid nodules on the fingers
What is a swan neck deformity?
When the PIPJ joint is hyperextended and DIPJ are flexed
Why does swan neck occur?
Tissues in palmar aspect of PIPJ become lax due to adjacent synovitis
Extension> flexion at this joint
At DIPJ elongation or rupture to inversion of extensor digitorum
What is Boutonnière deformity?
MCPJ and DIPJ hyperextended
PIPJ flexed
Why does Boutonnière deformity occur?
Inflammation of PIPJ lengthening of extensor digitorum at insertion
Lateral bands of extensor digitorum slip down sides of finger so now on palmar surface and instead as acting as extensors, act as flexors
What is Psoriatic arthropathy?
Arthritis develops in joints with overlying Psorosis
Affects DIPJs
How does Psoratic arthritis present?
Asymmetrically
Fusiform digits
Nail lesions (pitting)
Which joint is most commonly affected by OA?
1st CMC
How does OA in CMC joint present?
Pain at base of thumb
Stiffness
Swelling
1st metacarpal subluxes in ulnar direction = squaring of hand
What causes Heberden’s nodes?
OA
Cystic swelling containing gelatinous hyaluronic acid on dorsal aspect of DIPJ
Once inflammation subsides left with Osteophytes
Reduces manual dexterity
What is carpal tunnel syndrome?
Compression of median nerve as travels through carpal tunnel
What are risk factors of Carole tunnel syndrome?
Obesity
Pregnancy
Repetitive wrist work
RhA
Where is paraesthesia felt in carpal tunnel syndrome?
Distribution of median nerve
Thumb, index, middle and radial half of ring
Why is sensation to the palm spared in carpal tunnel syndrome?
The cutaneous branch of the medial nerve is given off before the carpel tunnel
Why can long standing carpel tunnel syndrome result in?
Weakness and atrophy of thenar muscles
Still able to flex thumb
Where can the ulnar nerve be compressed?
Guyon’s canal
Where is paraesthesia felt in ulnar nerve compression in wrist?
Ring and little fingers
Weakening of intrinsic muscles of hand supplied by ulnar nerve
What is Dupuyten’s contracture?
Localised thickening and contracture of palmar aponeurosis leading to flexion deformity of fingers
How does Dupuytren’s contracture develop?
Thickening in palm
Myofibroblasts in nodule contract forming tight bands called cords in palmar fascia
Fingers become stuck in flexed position due to close association with aponeurosis
What are risk factors for Dupuytren’s contracture?
Type 1 diabetes
Smoking
Heart disease
Trauma to hand and fingers
When do injuries to the radial nerve in the radial grove occur?
Mid- shaft humoral fractures
In radial groove nerve injuries what will the sensory impairment be?
Posterior cutaneous brach is before the radial groove so unaffected
Lower lateral and posterior cutaneous of forearm high in groove so normally fine
Paraestesia in superficial brach
What muscles are paralysed in radial groove nerve injuries?
Brachioradialis
All extensor muscles of wrist and fingers
What muscles are paralysed by a supracaondular fracture that damages the median nerve?
Flexor muscles from medial epicondyle
Pronators and flexors of wrist and hand
How will the arm appear in a supracondular fracture that damage the median nerve?
Supurnated
Weak flexion of wrist (adduction due to pull of flexor carpi ulnaris)
Flexion of thumb weak
What is the hand of Benediction?
When a patient attempts to are a fist with a high median nerve injury
Only able to flex medial 2 digits
What causes low level median nerve injuries?
Penetrating wrist injury
Compression of carple tunnel
What is the presentation of a low medial nerve injury?
Muscles paralysed= LOAF Lubricals to index and middle finger Opppones pollicis Abductor polllicis brevis Flexor pollicis brevis
Ape hand deformity
What is ape hand deformity?
Results from lower median nerve injury
Thenor eminence is flattered
Thumb adducted and laterally rotated
What functions will be lost in wrist level ulnar nerve injury?
Muscles of hypothenor eminence Adductor pollcis Deep head of flexor pollicis brevis Interossi Lumbricals the ring and little finger Palmaris brevis Palmar branches if medial 1 an a half digits
What is claw hand and why does it occur?
Little and ring finger hyperextended at MCPJ and flexed at both IPJ at rest
This is as lumbricals supplying these are paralysed (these flex at MCPJ and extend at IPJ)
What causes the ulnar never to be damaged in injuries at the elbow?
Medial epicondyle fractures
Compression of cubital tunnel
What muscles are affected in a high ulnar nerve injury?
Same as in a low injury
Paralysis of flexor carpi ulnaris
Ulnar half of flexor digitorum profundus
Loss of sensation in palmar and dorsal cutaneous branches
How does an ulnar claw appear with a high level ulnar nerve lesion?
Less pronounced than with lower injury
As no flexion at DIPJ of medial fingers as flexor digitorum profundus paralysed
Only hyperextension at MCPJs
