34. Common conditions of the hand and wrist

Question 1

What is the common mechanims for scaphoid fracture?

Answer 1

fall onto an outstretched hand (resulting in hyperextension and impaction of the scaphoid against the rim of the radius, or in direct axial (‘end on’) compression of the scaphoid)

Question 2

Who are more prone to get scaphoid fractures?

Answer 2

They may occur at any age, but are most common amongst adolescents and young adults following a fall onto an outstretched hand

Question 3

What % of carpal bone fractures and hand fractures does scaphoid fractures account for?

Answer 3

Scaphoid fractures account for 70-80% of fractures of the carpal bones and 10% of all hand fractures.

Question 4

What do patients with scaphoid fracture usually complain of?

Answer 4

• pain in the anatomical snuffbox
• pain is exacerbated by moving the wrist
• swelling around the radial and posterior aspects of the wrist
• . Passive range of motion is reduced

Question 5

Which part of the scaphoid is most usually fractured?

Answer 5

most commonly affect the waist of the scaphoid (70-80%) but can also occur in the proximal pole (20%) or the distal pole (10%), which is sometimes called the scaphoid tubercle.

Question 6

Why is delayed diagnosis common in scaphoid fractures?

Answer 6

• Fracture line may not show immediately on x-ray
• x ray again 10-14 days - fracture line may become more visible after some bone resorption
• CT or MRI - if still symptomatic and cannot see on xray

Question 7

What are the complications that may occur with a displaced scaphoid fracture?

Answer 7

high risk of non-union (8-10%), malunion, avascular necrosis and late complications of carpal instability and secondary osteoarthritis.

Question 8

Why might a scaphoid fracture lead to avascular necrosis?

Answer 8

The blood supply to the scaphoid is mainly retrograde from the distal to the proximal pole, and since the blood supply to the proximal pole is tenuous, fractures through the waist of the scaphoid can result in avascular necrosis

Question 9

In a scaphoid fracture, what factors might maker osteoarthritis more likely to occur?

Answer 9

Osteoarthritis is more common if there has been non-union, malunion or avascular necrosis.

Question 10

What is a colles fracture?

Answer 10

an extra-articular fracture of the distal radial metaphysis, with dorsal angulation and impaction.

Question 11

What is commonly associated with a colles fracture?

Answer 11

ulnar styloid fracture

Question 12

Who are colles fracture common in?

Answer 12

particularly common in patients with osteoporosis (reduced bone density), and as such they are most frequently seen in post-menopausal women. Younger
patients who present with a Colles’ fracture have usually been involved in high impact trauma e.g. skiing

Question 13

What is the common mechanism of colles fracture?

Answer 13

a fall onto an outstretched hand with a pronated forearm and wrist in dorsiflexion

Question 14

Why is colles fracture dorsally angulated and impacted?

Answer 14

The energy is transmitted from the carpus to the distal radius in a dorsal direction and along the long axis of the radius. The fracture is therefore dorsally angulated and impacted

Question 15

What will a patient present with in colles fracture?

Answer 15

The patient will present with a painful, deformed, swollen wrist

Question 16

What can be seen on an x ray of colles fracture?

Answer 16

fracture line, dorsal angulation and impaction are

usually clearly visible on plain Xrays, especially the lateral view

Question 17

How are most colles fractures treated?

Answer 17

treated by reduction and immobilisation in a cast.

Question 18

What are the complications of colles fracture?

Answer 18

• malunion, resulting in a ‘dinner-fork’ deformity
• median nerve palsy and post-traumatic carpal tunnel syndrome
• secondary osteoarthritis (more common with intra-articular fractures)
• tear of the extensor pollicis longus tendon(through attrition of the tendon over a sharp fragment of bone)

Question 19

What is a Smith’s fracture?

Answer 19

Fractures of the distal radius with volar (palmar) angulation of the distal fracture fragment(s)

Question 20

What is the typical mechanism of Smith’s fractures?

Answer 20

a fall onto the dorsum of a flexed wrist or a direct blow to the back of the wrist.

Question 21

Who are smiths fracture common in?

Answer 21

typically occur in young males (most common) and elderly females

Question 22

What are complications of Smith’s fractures?

Answer 22

Malunion of a Smith fracture, with residual volar displacement of the distal radius results in a cosmetic deformity referred to as a ‘garden spade’ deformityThe garden spade deformity narrows and distorts the carpal tunnel and can result in carpal tunnel syndrome.

Question 23

What is the pathogeneis of rheumatoid arthritis?

Answer 23

autoimmune disease in which autoantibodies, known as rheumatoid factor, attack the synovial membrane. The inflamed synovial cells proliferate to form a pannus, which penetrates through the cartilage and adjacent bone, leading to joint erosion and deformity

Question 24

What joints does rheumatoid arthritis commonly affect?

Answer 24

particularly affects the metacarpophalangeal joints (MCPJ) and proximal interphalangeal joints (PIPJ) of the hands and feet, and the cervical spine

Question 25

Why is Rheumatoid arthritis usually described as a symmetrical polyarthritis?

Answer 25

Rheumatoid arthritis is usually described as a symmetrical polyarthritis, meaning that it affects multiple joints usually in a symmetrical distribution (e.g. right and left wrists at the same time). This symmetrical inflammation can make mild swelling in the hand difficult to diagnose, as there is no ‘normal’ hand with which to make a comparison.

Question 26

What might a patient present with in rheumatoid arthritis?

Answer 26

• pain and swelling of the PIPJs and MCPJs of the fingers
• erythema overlying the joints (indicating inflammation)
• stiffness, that is worst in the morning or after periods of inactivity
• carpal tunnel syndrome (compression of the median nerve in the carpal tunnel, in this case due to synovial swelling)
• fatigue and flu-like symptoms (due to the systemic nature of rheumatoid disease)

Question 27

What are the x ray features of the Rheumatoid arthritis?

Answer 27

• reduced joints space
• periarticular osteopenia
• juxta-articular bony erosion
• subluxation (partial dislocation) and gross deformity

Question 28

In rheumatooid arthritis, at which stage do rheumatoid nodules present?

Answer 28

Rheumatoid nodules in the fingers and over the elbow are usually a late feature of rheumatoid disease

Question 29

What are 2 deformities of advanced rheumatoid arthritis?

Answer 29

• Swan neck deformity

- Boutonniere deformity

Question 30

What is swan neck deformity?

Answer 30

Swan neck deformity occurs when the PIPJ hyperextends and the MCPJ and DIPJ are flexed.

Question 31

Why does swan neck deformity occur?

Answer 31

the tissues on the volar (palmar) aspect of the proximal
interphalangeal joint (PIPJ) become lax as a result of the adjacent synovitis; this is the primary abnormality. There is an imbalance between the muscle forces acting on the PIPJ (extension > flexion) so the joint, with its lax tissues on the volar surface, becomes hyperextended. At the distal interphalangeal joint, there is either elongation or rupture of the insertion of extensor digitorum into the base of the distal phalanx, resulting in a mallet deformity

Question 32

What is boutonniere deformity?

Answer 32

the metacarpophalangeal joint (MCPJ) and distal interphalangeal joint (DIPJ) are hyperextended and the PIPJ is flexed.

Question 33

Why does Boutonniere deformity occur?

Answer 33

inflammation in the PIPJ leads to lengthening (or rupture) of the central slip of extensor digitorum at its insertion into the base of the middle phalanx on the dorsal surface of the finger. The lateral bands of the extensor digitorum tendon slip down the sides of the finger so that they are now on the palmar surface at the level of the PIPJ and, instead of acting as extensors of the PIPJ (as they usually would), start to act as flexors at the PIPJ, as well as hyperextending the DIPJ

Question 34

What is psoriasis and where does it characteristically occur?

Answer 34

skin condition that causes red, flaky patches of skin covered with silvery scales. The patches characteristically occur on the elbows, knees, scalp and lower back, but can occur anywhere.
1-2% of the population have psoriasis

Question 35

What is the pattern of arthritis development in association with psoriasis?

Answer 35

Only a minority of patients with psoriasis will develop arthritis. When it develops, it is usually an asymmetrical oligoarthritis (it develops in one joint at a time, progressing in an asymmetrical manner e.g. left big toe then right index finger).
Psoriatic arthritis involves the small joints of the hands and feet most commonly

Question 36

What do patients with psoriatic athropathy present with?

Answer 36

The patients present with fusiform (sausage-shaped) swelling of the digits, known as dactylitis (=swollen digits). The affected joints stiffen and if the disease progresses, it can progress to a widespread joint destruction called arthritis mutilans

Question 37

Which joints does psoriatic arthritis affect most commonly?

Answer 37

Unlike rheumatoid arthritis (which affects the MCPJs and PIPJs), psoriatic arthritis most commonly affects the DIPJ

Question 38

What other symptom do patients with Psoriatic arthropathy also have?

Answer 38

80% of patients also have nail lesions, such as pitting and onycholysis (separation of the nail from the nail bed)

Question 39

Which joint in the hand is most commonly affected by osteoarthritis?

Answer 39

1st carpometacarpal joint (between the trapezium and the first metacarpal)

Question 40

In which gender is Osteoarthritis of the 1st CMC joint more common in?

Answer 40

more common in women

Question 41

What do patients with OA in the first CMC joint complain of?

Answer 41

• The patients complain of pain at the base of their thumb.
• The pain is exacerbated by movement and relieved by rest.
• Stiffness increases following periods of rest (e.g. in
  the mornings).
• There may be some swelling evident around the base of the thumb.
• In the later stages, the first metacarpal subluxes in an ulnar direction, resulting in loss of the normal contour and ‘squaring of the hand
• Osteoarthritis of the fingers occurs most often in the fifth or sixth decade of life, and patients usually describe a gradual onset of pain in the distal interphalangeal joints

Question 42

What are Herberden’s nodes?

Answer 42

Classic sign of osteoarthritis and affect the DIPJ

Question 43

What happens in Herberden’s nodes?

Answer 43

Heberden’s nodes begin with either a chronic swelling of the affected joints or a sudden onset of pain, swelling and loss of manual dexterity. Initially, the patient develops a cystic swelling containing gelatinous hyaluronic acid on the dorsolateral aspect of their DIP joint. The initial inflammation and pain eventually subside and the patient is left with an osteophyte.

Question 44

Who are Heberden’s nodes more common in?

Answer 44

They typically develop in middle age, are more common in women than men and tend to run in families, suggesting a genetic predisposition.

Question 45

What are Bouchard’s nodes?

Answer 45

Herberden’s nodes on the PIPJ

Question 46

What is carpal tunnel syndrome?

Answer 46

Compression of the median nerve as it passes through the carpal tunnel from the forearm into the hand

Question 47

What are the risk factors for carpal tunnel syndrome?

Answer 47

obesity, repetitive wrist work, pregnancy, rheumatoid arthritis and hypothyroidism.

Question 48

What does the patient with carpal tunnel syndrome complain of?

Answer 48

complains of paraesthesia in the distribution of the median nerve (thumb, index finger, middle finger, radial half of ring finger)

Question 49

When are symptoms of carpal tunnel worse and why?

Answer 49

Worse at night, wrist flexion further narrowing carpal tunnel and often wake the patient from sleep

Question 50

Which daily activities can aggravate the parasthesia due to carpal tunnel syndrome?

Answer 50

As the conditions worsens, daily activities such as

driving, combing hair, holding a book or phone, can aggravate the paraesthesia.

Question 51

Why is sensation to the palm spared in carpal tunnel syndrome?

Answer 51

palmar cutaneous branch of the median nerve branches proximal to the carpal tunnel and passes superficial to it into the palm so isn’t compresssed

Question 52

Why is the motor branch of the median affected in carpal tunnel syndrome? What does this result in?

Answer 52

The motor branch of the median nerve to the thenar muscles exits the median nerve distal to the carpal tunnel. Hence long-standing carpal tunnel syndrome can result in muscle weakness and atrophy of the thenar muscles (flexor pollicis brevis [superficial head], abductor pollicis brevis and opponens pollicis).

Question 53

In carpal tunnel syndrome, despite compression of median nerve, why can the thumb still be flexed and adducted?

Answer 53

The patient will still be able to flex their thumb as flexor pollicis longus is innervated by the anterior interosseous branch of the median nerve in the forearm, and the deep head of flexor pollicis brevis is innervated by
the ulnar nerve.
Adduction of the thumb is also spared as adductor pollicis is supplied by the ulnar nerve

Question 54

In carpal tunnel syndrome, what is the effect on manual dexterity?

Answer 54

Because of the motor and sensory disturbance, manual dexterity is diminished and difficulty with daily activities such as buttoning clothes and picking up small objects is often encountered.

Question 55

Where might pain be felt in carpal tunnel syndrome?

Answer 55

proximally in the forearm, elbow, shoulder and neck in up to one third of patients

Question 56

What is Guyon’s canal syndrome?

Answer 56

The ulnar nerve can be compressed in Guyon’s canal, as it passes radial (lateral) to the pisiform bone over the volar surface of the flexor retinaculum.

Question 57

What do patients complain of in Guyon’s canal syndrome?

Answer 57

Paraesthesia in the ring and little fingers, progressing to weakness of the intrinsic muscles of the hand supplied by the ulnar nerve (notably adductor pollicis and the palmar and dorsal interossei; also lumbricals to ring and little fingers and deep head of flexor pollicis brevis, but these are not usually noticed by patients)

Question 58

What is Dupuytren’s contracture?

Answer 58

Localised thickening and contracture of the palmar aponeurosis leading to a flexion deformity of the adjacent fingers

Question 59

How does Dupuytren’s contracture develop?

Answer 59

Patient notices a thickening or ‘nodule’ in their palm, which can be painful or painless. Later in the disease process, the myofibroblasts within the nodule contract leading to the formation of tight bands called ‘cords’ in the palmar fascia. The overlying skin is tightly adherent to the palmar aponeurosis and becomes involved in the disease, which also progresses to involve the proximal fascia and skin of the fingers. The fingers become stuck in a flexed position and cannot be passively straightened (this is called ‘fixed flexion’)

Question 60

Which fingers are most commonly affected by Dupuytren’s contracture?

Answer 60

ring and little finger, but the first webspace and thumb may also be involved.

Question 61

Which group of people are more likely to present with Dupuytren’s contracture?

Answer 61

most commonly occurs between 40 and 60 years of age. It is more common in males and in persons of Northern European origin. 70%of cases have a family history of the condition and inheritance is autosomal dominant. The remainder of cases are sporadic.

Question 62

What are the Conditions that increase the risk of developing Dupuytren’s contracture?

Answer 62

• Type 1 diabetes
• Having had adhesive capsulitis of the shoulder
• Epilepsy, taking certain medications e.g. barbiturates, phenytoin
• Liver disease and/or excessive alcohol consumption
• Smoking
• Hypercholesterolaemia
• Heart disease
• HIV
• Hypo- or hyperthyroidism
• Trauma to the hand or fingers
• Vibration-related hand injury (e.g. working with vibrating tools regularly for > 10 years)