Hand and Wrist (Session 9) Flashcards
What percentage of carpal bone fractures do scaphoid fractures account for?
70-80%
(10% of all hand fractures)
What is the most common mechanism for a scaphoid fracture?
FOOSH (young adults)
=Hyperextension and impaction of scaphoid against rim of radius
Where do patients usually complain of pain if they have a scaphoid fracture?
Anatomical snuffbox
- Pain=exacerbated by moving wrist*
- Swelling around radial and posterior aspects of wrist*
Where and how commonly do fractures occur in the scaphoid (%)?
- Waist: 70-80%
- Proximal pole: 20%
- Distal pole: 10%
Why are follow-up x-rays sometimes required for a scaphoid fracture? (10-14days after)
- May not show up initially
- Fracture line may be more visible after some bone reabsorption
(In the meantime- patient should be treated as if they have a fracture if it is suspected)
If a suspected scaphoid fracture still doesn’t show up on an x-ray after 10-14 days and the patient is still symptomatic what should be done?
CT/MRI
Describe the blood supply to the scaphoid.
- Mainly retrograde (from distal to proximal pole)
- Blood supply to proximal pole=tenuous
What type of scaphoid fracture can result in avascular necrosis?
Waist of scaphoid
What complications can arise from a fracture in the waist of the scaphoid?
- Non-union (8-10%)
- Malunion
- Avascualr necrosis
- Carpal instability
- Secondary osteoarthritis (non-union, malunion, avascular necrosis)
What is a Colles’ fracture?
- Extra-articular
- Distal radial metaphysis
- Dorsal angulation and impaction
What other fracture is associated with a Colles’ fracture in 50% of cases?
Ulnar styloid fracture
In which patients are Colles’ fractures common?
(colles’ fracture= most common type of wrist fracture)
- Patients w./ Osteoporosis
- Post menopausal women
What is the usual mechanism of injury for a Colles’ fracture?
FOOSH
How will a patient with a Colles’ fracture present?
Wrist=
- Painful
- Deformed
- Swollen
How are most Colles’ fractures treated?
Reduction
Immobilisation in cast
What complications can arise following a Colles’ fracture?
- Malunion (dinner fork deformity)
- Median nerve palsy
- Post traumatic carpal tunnel syndrome
- Secondary osteoarthritis
- Tear of extensor pollicis longus tendon
What is a Smith fracture?
- Distal radius
- Palmar (volar) angulation- of distal fragment
What % of smith fractures are extra-articular?
85%
What % of fractures of the radius and ulna to smith fractures account for?
<3%
WIn which patients are Smith fractures common?
- Young men
- Elderly women
What are the 2 typical mecahnisms for a Smith fracture?
- Fall onto flexed wrist
- Direct blow to back of wrist
What is the ‘garden spade’ deformity?
- Malunion of Smith fracture
- Residual volar displacement of distal radius
What complication can follow the ‘garden spade deformity’?
Deformity narrows-distorts carpal tunnel
=Carpal tunnel syndrome
What is Rheumatoid arthritis? (include the mechanism of its pathology)
- Autoimmune disease
- Autoantibodies= rheumatoid factor
- Attack synovial membrane
- Inflamed synovial cells- proliferate
- Form pannus - penetrate through cartilage and adjacent bone
- Causes erosion and deformaties
Name 3 joints which are commonly affected by rheumatoid arthritis.
- Metacarpophalangeal joints (MCPJ) (Hands and feet)
- Proximal interphalangeal joints (PIPJ) (Hands and feet)
- Cervical spine
Rheumatoid arthritis is often described as ‘symmetrical polyarthritis’. What does this mean?
- Affects multiple joints
- Symmetrical distribution
If a patient has rheumatoid arthritis, how might they present? (7)
- Pain and swelling of joint
- Erythema (redness) overlying joints
- Stiffness- worst in morning/inactvity
- Carpal tunnel syndrome (synovial swelling)
- Fatigue/flu-like symptoms (systemic nature of disease)
- Rheumatoid nodules - in fingers/elbows (late feature)
- Deformities
What are the X-ray features of rheumatoid arthritis? (LESS)
- Loss of joint space
- Erosions
- Soft tissue Swelling
- Soft bones (osteopenia)
Name 2 deformities that can be seen in patients with advanced rheumatoid arthritis?
- Swan neck deformity
- Boutonniere deformity
Describe the ‘swan neck deformity’.
- PIPJ hyperextends
- MCPJ flexed
- DIPJ flexed
Explain the ‘swan neck’ deformity
- PIPJ- laxed as adjacent synovitis
- Imbalance between muscles acting on PIPJ
- DIP- elongation/rupture at insertion of extensor digitorum
Describe the Boutinniere deformity.
- MCPJ= hyper extended
- DIPJ= hyper extended
- PIPJ= flexed
Explain the Boutinniere deformity
- Inflammation in PIPJ
- Lengthening/rupture of extensor digitorum on dorsal surface of finger
- Lateral band slips- acts on palmar surface- act as flexor rather than extensor
What is psoriasis?
- Skin condition
- Causes:
- red, flaky patches of skin- covered with silvery scales
Where does psoriasis characteristically occur?
- Elbows
- Knees
- Scalp
- Lower back
- Can occur anywhere
What % of the population has psoriasis?
1-2%
Does psoriatic arthritis usually develop in a symmetrical of assymetrical manner?
Assymetrical
How do patients with psoriatic arthritis usually present?
- Fusiform (sausage shaped) swelling of digits (dactylitis)
- Joints stiffen
Can develop into Arthritis mutilans (widespread joint destruction
Rheumatoid arthritis most commonly affects MCPJs and PIPJs. Which joint does psoriatic arthritis most commonly affect?
DIPJs
What other symptoms do 80% of patients which are affected by psoriatic arthritis have?
- Nail lesions:
- Pitting
- Onycholyis (separating nail from nail bed)
Name 2 other conditions where Onycholyis (separating nail from nail bed) is seen.
- Hyperthyroidism
- Fungal nail infection
Which joint in the hand is most commonly affected by osteoarthritis?
1st Carpo Metacarpal joint
(between trapezium and first metacarpal)
In what population is osteoarthritis in the first carpometacarpal joint more common?
Women (1/3 of women over 40 yrs will have x-ray changes)
How will a patient with osteoarthritis in the first carpometacarpal joint present?
- Pain at base of thumb
- Pain exacerbated by movement, relieved by rest
- Stiffness increased following periods of rest
- Swelling may be evident at base of thumb
-
Squaring of hand (Later)
- First metacarpal subluxes- ulnar direction
- Loss of normal contour
During which decades of life are patients likely to acquire osteoarthritis in their fingers?
5th/6th
What are Heberden’s nodes?
- Classic sign of osteoarthritis
- Typically develop-middle age
- Tend to run in families
- More common in women
- Affect DIPJ
- Chronic swelling of affected joint
- Sudden onset of:
- Pain
- Swelling
- Loss of manual dexterity
- Cystic swelling- contains gelatinous hyaluronic acid-osteophyte left when inital pain and inflammation subsides
What are Bouchard’s nodes?
- Classic sign of osteoarthritis
- Typically develop-middle age
- Tend to run in families
- More common in women
- Affect PIPJs
- Chronic swelling of affected joint
- Sudden onset of:
- Pain
- Swelling
- Loss of manual dexterity
- Cystic swelling- contains gelatinous hyaluronic acid-osteophyte left when inital pain and inflammation subsides
What is carpal tunnel syndrome?
- Compression of median nerve as is passes through carpal tunnel
- Most common site of nerve entrapment
Name some risk factors for carpal tunnel syndrome. (5)
- Obesity
- Repetitive wrist work
- Pregnancy
- Rheumatoid arthritis
- Hypothyroidism
Name some complications which may follow nerve compression in carpal tunnel syndrome. (4)
- Ischaemia
- Focal demyelination
- Decrease in axonal calibre
- Axonal loss
How will a patient with carpal tunnel syndrome present?
- Paraesthesia in distribution of median nerve
- Symptoms=worse at night (wrist drifts into flexion- narrows carpal tunnel further)
- Daily activities can aggravate parasthesia eg driving, combing hair, holding phone
- Manual dexterity= diminished and difficulty with daily actvities eg buttoning clothes
- Pain in: forearm, elbow, shoulder, neck (up to 1/3 patients)
Why is sensation to the palm spared in carpal tunnel syndrome?
Palmar cutaneous branch of median nerve branches proximal to carpal tunnel and passes superficial to it
What may happen to the thenar muscles as a result of carpal tunnel syndrome?
- Flexor pollicis brevis (superficial head)
- Abductor pollicis brevis
- Opponens pollicis
- Muscle weakness
- Atrophy
Motor branch of median nerve exits distal to carpal tunnel (supplies thenar muscles)
If a patient has long standing carpal tunnel syndrome, will they still be able to flex and adduct their thumb?
Yes:
- Flexor pollicis longus innervated by anterior interosseous branch of median nerve
- Flexor pollicis brevis (deep head) innervated by ulnar nerve
- Adductor pollicis innervated by ulnar nerve
What is another name for Ulnar nerve compression in Guyon’s canal?
- Ulnar tunnel syndrome
- Guyon’s canal syndrome
- Handlebar palsy
How will a patient with ‘Guyon’s canal syndrome present’?
- Parasthesia -ring and little fingers
- Weakness in intrinsic muscles of hand supplied by ulnar nerve
- Adductor pollicis
- Palmar and dorsal interossei
- Lumbricals to ring and little fingers
- Deep head of flexor pollicis brevis
What is Dupuytren’s contracture? (Common condition)
- Localised thickening+contracture of palmar aponeurosis
- Causes flexion and deformity
- Thickening/nodule in palm (painless/painful)
- Myofibroblasts in nodule contract
- Tight bands (cords) form
- Overlying skin tightly adherent to palmar aponeurosis-now involved
- Fingers stuck in flexed position (fixed flexion)
Which digits are commonly affected by Dupuytren’s contracture?
- Ring finger
- Little finger
- Thumb (may be involved)
What population does Dupuytren’s commonly occur in?
40-60 years
70% cases have family history- autosomal dominant
More common in males + northern european origin
Name 4 examples of conditions that increase a persons risk of developing Dupuytren’s contracture:
- Type 1 diabetes
- Smoking
- Hypercholesterolaemia
- Heart disease
- HIV
- Hypo/hyperthyroidism
- Trauma to hand/fingers
