Common Wrist& Hand Conditions

Question 1

What is the main cause of distal radius +/- ulna fractures? Which condition is a risk factor for this type of fracture?

Answer 1

• FOOSH

- Osteoporosis

Question 2

What are the symptoms of radius/ulna fracture?

Answer 2

1. Pain
2. Swelling
3. ‘Dinner fork’ deformity

Question 3

What is the difference between Colles’ and Smith’s fracture?

Answer 3

• Colles’ = dorsal displacement and angulation, shortening (hand flexes up)
• Smith’s = palmar displacement and angulation (hand bends inwards)

Question 4

Which carpal bone is most frequently fractured? What is the most common cause? In which age group is this most common?

Answer 4

• Scaphoid
• FOOSH
• Teens and 20s

Question 5

What is the main symptom of a scaphoid fracture?

Answer 5

tenderness in ‘anatomical snuffbox’

Question 6

Why is it difficult to diagnose scaphoid fractures? How is this problem dealt with?

Answer 6

May be hard to see on inital X-rays.

Further X-ray performed after 10 days, and re-examination/MRI scan.

Question 7

Why is X-ray diagnosis of scaphoid fractures easier 10 days after initial presentation?

Answer 7

Blood supply to area increases (1st step in bone repair) so fracture line becomes more distinct.

Question 8

Why is scaphoid fracture particular prone to complications?

Answer 8

Scaphoid has a unique blood supply, which runs distal to proximal. Fracture can disrupt supply to proximal portion - failure to revascularise the scaphoid can cause avascular necrosis and future arthritis.

Question 9

What is ulnar nerve neuropathy? What are the symptoms?

Answer 9

‘Cubital tunnel syndrome’, = compressive neuropathy of ulnar nerve at elbow

Affects ulna 1 1/2 digits:

• parathesiae
• numbness
• weakness.

Question 10

How is diagnosis of ulnar nerve neuropathy confirmed, what is the differential diagnosis and how is this treated?

Answer 10

Nerve conduction studies to confirm diagnosis. Coulf also be compression at neck or wrist.

Treatment:

• splintage
• decompression +/- anterior transposition of nerve

Question 11

Which conditions likely causes pain when gripping/tenderness/swelling of the anatomical snuffbox?

Answer 11

De Quervain syndrome - tenosynovitis of abductor pollicis longus and extensor pollicis brevis

Question 12

How is De Quervain syndrome diagnosed?

Answer 12

Finkelstein’s test: grasp thumb and ulnar deviate the hand sharply. If sharp pain along distal radius = de Quervain’s tenosynovitis.

Question 13

What is Dupuytren’s contracture?

Answer 13

(Predominantly) inherited connective tissue disorder causing palmar fibromatosis (build up of scar tissue/benign tumours). Causes 1 or more fingers to flex towards hand - cannot fully extend.

Question 14

What are the risk factors for Dupuytren’s contracture?

Answer 14

1. caucasian, esp. scandinavian
2. diabetes
3. smoking
4. certain medications, eg for epilepsy

Question 15

What is the difference between rheumatoid and osteoarthritis?

Answer 15

OA

i) wear/tear of articular cartilage
ii) may be uni or bilateral, usually affects weight bearing joints
iii) inflammatory signs less common
iv) morning stiffness <20min
v) osteophytes may be present

RA

i) autoimmune response affecting synovial membrane leading to joint destruction
ii) usually symmetrical, primarily affects smaller joints
iii) signs of inflammation
iv) morning stiffness often >1hr
v) osteophytes absent

Question 16

Which hand joints do OA and RA predominantly affect?

Answer 16

OA:

• wrists
• metacarpophalangeal (MCP), esp. of thumb (1st MCP)
• proximal interphalangeal (PIP)
• distal interphalangeal (DIP)

RA:
- wrists
- metacarpophalangeal (MCP)
- proximal interphalangeal (PIP)
(rarely affects distal interphalangeal)

Question 17

What is swan neck deformity?

Answer 17

• Flexion of MCP, hyper-extension of PIP and flexion of DIP

- Most commonly caused by rheumatoid arthritis

Question 18

What are Bouchard’s and Heberden’s nodes?

Answer 18

Bony nodules at the PIP (Bouchard’s) and DIP (Heberden’s) joints in osteoarthritis

Question 19

What is carpal tunnel syndrome?

Answer 19

compression of median nerve within the carpal tunnel (can be caused by thickened ligaments and tendon sheaths)

Question 20

What is the consequence of carpal tunnel syndrome if it is untreated?

Answer 20

weakness and atrophy of thenar muscles

Question 21

What are the symptoms of carpal tunnel syndrome?

Answer 21

• numbness, tingling and pain in thumb, index, middle, and 1/2 ring fingers
• pain usually radiates to forearm
• symptoms often worse at night and in morning

Question 22

Which tests can be performed to diagnose carpal tunnel syndrome?

Answer 22

1. Tinel’s sign: tapping nerve in carpal tunnel to elicit pain in median nerve distribution
2. Phalen’s manoeuvre: holding wrist in flexion for 60sec to elicit pain in median nerve distribution

Question 23

In which 2 locations can the ulnar nerve commonly be compressed? What are the associated conditions called?

Answer 23

1. Ulnar tunnel syndrome - compression in Guyon’s canal

2. Cubital tunnel syndrome - compression in cubital tunnel by elbow

Question 24

What are the symptoms of ulnar/cubital tunnel syndrome?

Answer 24

• tingling in little finger and 1/2 ring finger

- progresses to loss of sensation and/or impaired motor function of intrinsic hand muscles innervated by ulnar nerve

Question 25

What is Boxer's fracture?

Answer 25

fracture of 5th metacarpal (little finger) usually as a result of punching something hard

Question 26

What is complex regional pain syndrome/reflex sympathetic dystrophy?

Answer 26

Chronic degenerative condition resulting from an aberrant response to tissue injury or surgery - dysregulation of CNS and autonomic NS.

Question 27

What are the symptoms of CRPS?

Answer 27

1. pain and extreme sensitivity 2. muscle spasms 3. local rubor and tumor 4. hyperhydrosis 5. thinnng of bones

Question 28

What is the 'ulnar claw' and what is it a sign of?

Answer 28

Little finger and ring finger are: - hyper extended at MCP joint - flexed at both proximal and distal IP joints Caused by ulnar nerve damage at wrist.

Question 29

Why does an ulnar nerve lesion at the wrist cause ulnar claw?

Answer 29

Paralysis of medial 2 lumbricals (supplied by ulnar nerve) leading to: - loss of flexion at MCP joint - loss of extension at IP joints Results in: - hyperextension of MCP joints by unopposed extensor digitorum - flexion of IP joints by unopposed flexor digitorum profundus and superficialis

Question 30

Why does an ulnar nerve lesion at the elbow cause less clawing than lesion at the wrist (ulnar paradox)?

Answer 30

Causes paralysis of flexor digitorum profundus as well as lumbricals - no flexion of distal IP joints of ring and little fingers. Ulnar claw now only consists of MCP joint hyperextension and proximal IP joint flexion - much less evident.

Question 31

Why is tingling in palm of hand not a symptom of carpal tunnel syndrome?

Answer 31

Because palm of hand is innervated by the palmar branch of the median nerve (rather than palmar digital branch) which travels superficially to flexor retinaculum (unlike most of the median nerve innervation of the hand) - so remains functioning during CTS.

Question 32

Which muscles will be paralysed by transection of the median nerve at the wrist?

Answer 32

- lateral 2 lumbricals - abductor pollicis brevis - deep head of flexor pollicis brevis

Question 33

What are the signs and symptoms of median nerve lesion at the wrist?

Answer 33

i) lack of ability to abduct, flex and oppose the thumb - paralysis of thenar muscles ("ape-hand deformity") ii) loss of flexion at MCP joints of index and middle fingers iii) sensory loss in thumb, index finger, middle finger and 1/2 ring finger

Question 34

What is wrist drop a sign of? Why does this occur?

Answer 34

- Sign of: radial nerve injury proximal to elbow - Radial nerve innervates wrist extensor muscles - are paralysed in nerve lesion. Tone of flexor muscles then produces unopposed flexion of wrist joint

Question 35

What are the 2 common sites of damage to the radial nerve in wrist drop?

Answer 35

1. axilla - injured via humeral dislocation or fractures of proximal humerus 2. radial groove of humerus - injured via humeral shaft fracture