Conditions of the hand + wrist

Question 1

What is the cause and symptoms of a scaphoid fracture?

Answer 1

FOOSH
Pain in anat. snuffbox, swelling on radial + post. wrist
Most common in waist of scaphoid
(fracture line may not be visible @ 1st)

Question 2

Why do scaphoid fractures result in avascular necrosis?

Answer 2

Retrograde blood supply

Risk of non-union/malunion/OA

Question 3

What is a Colles’ fracture? How do they commonly occur in?

Answer 3

Extra-articular fracture of distal radial metaphysis, with dorsal angulation + impaction
Osteoporotic/young with high impact trauma
FOOSH with pronated forearm, dorsiflexed wrist

Question 4

How is a Colles’ fracture treated and what are the complications?

Answer 4

Reduction + immobilisation in cast
Malunion = dinner fork deformity
Median nerve palsy + post-traumatic carpal tunnel syndrome
Secondary OA
Tear of ext. pollicis longus tendon

Question 5

What is a Smith fracture?

Answer 5

Fracture of distal radius with volar (palmar) angulation of distal fracture fragments (most are extra-articular = reverse Colles’ fracture)

Question 6

Who does a Smith fracture commonly occur in and how? What deformity is common?

Answer 6

Young males, elderly females
Fall on flexed wrist/direct blow to back of wrist
Garden spade deformity = malunion + volar displacement of distal radius, narrows carpal tunnel

Question 7

What is Dupuytren’s contracture?

Answer 7

Localised thickening + contracture of palmar aponeurosis = flexion of adjacent fingers

Question 8

What is the process of Dupuytren’s contracture?

Answer 8

Myofibroblasts in nodule contract = tight bands/cords form in palmar fascia
Fixed flexion of ring/little finger
40-60yrs, male

Question 9

What conditions increase the risk of Dupuytren’s contracture?

Answer 9

Type 1 diabetes
Heart disease
Smoking
HIV

Question 10

What are the symptoms of RA of the MCPJ and ICPJ of the hand?

Answer 10

Pain/swelling of these joints
Erythema over joints
Carpal tunnel syndrome
Fatigue/flu-symptoms = from systemic nature of disease

Question 11

What are the 4 x-ray features of RA?

Answer 11

Joint space narrowing
Periarticular osteopenia
Juxta-articular bony erosions
Subluxation, gross deformity

Question 12

What is a swan neck deformity as a result of RA?

Answer 12

Tissues on volar (palmar) aspect of proximal IPJ become lax from adjacent synovitis = hyperextends
@ distal IPJ = elongation/rupture of extensor digitorum = mallet deformity

Question 13

What is a Boutonniere deformity as a result of RA?

Answer 13

MCPJ + distal IPJ hyperextended, proximal IPJ flexed

Inflammation of prox. IPJ = lengthening of central slip of ext. digitorum = lateral bands slip so act as flexors of prox. IPJ (rather than ext.)

Question 14

Describe the symptoms of psoriatic arthropathy (psoriasis)

Answer 14

Asymmetrical oligoarthritis = develops in 1 joint @ a time
Fusiform swelling of digits (dactylitis), stiffened joints, arthritis mutilans (widespread joint destruction)
Common in distal IPJs, nail lesions (pitting + onycholysis)

Question 15

What joint in the hand is most commonly affected by OA? What are the symptoms?

Answer 15

1st carpometacarpal joint (trapezium + 1st metacarpal)
More common in women

Pain @ base of thumb, exacerbated by movement, stiffness after rest
Subluxation of 1st metacarpal in ulnar direction = squaring of hand

Question 16

What are Heberden’s nodes?

Answer 16

Sign of OA in distal IPJ
Start with chronic swelling + loss of manual dexterity
Cystic swelling of hyaluronic acid on dorsolateral aspect of IPJ = ends with osteophyte

Question 17

What are Bouchard’s nodes?

Answer 17

Same as Heberden’s nodes in proximal IPJ

Question 18

What is carpal tunnel syndrome? What are the risk factors? What are the results and symptoms?

Answer 18

Compression of median nerve as passes through carpal tunnel into hand
Obesity/repetitive wrist work/pregnancy/RA/hypothyroidism
Ischaemia/focal demyelination/axonal loss
Paraesthesia in distribution of median nerve, worse @ night (wrist drifts into flexion), bilateral thenar muscle wasting

Question 19

In carpal tunnel syndrome, why is sensation to the palm spared?

Answer 19

Palmar cutaneous branch of median nerve branches prox. to carpal tunnel + superficially into hand = not compressed

Question 20

Why can carpal tunnel syndrome result in muscle weakness + atrophy of the thenar muscles?

Answer 20

Motor branch of median nerve to thenar muscles exits distal to carpal tunnel

Question 21

What is ulnar tunnel syndrome/Guyon’s canal syndrome or handlebar palsy?

Answer 21

Ulnar nerve compressed in Guyon’s canal as it passes lateral to pisiform over flex. retin.
Paraesthesia in ring/little fingers = weakness of intrinsic muscles supplied by ulnar nerve