Hand and wrist

Question 1

How will a patient present who has damaged their ulnar nerve

Answer 1

Hyperextension of metacarpalphalangeal joint due to unoppsed action of extensor digitorum and exntensor minimi
Flexion of the distal and proximal interphalangeal joint due to loss of dorsal interossei and medial lumbricals extend at the IP joints - flexion
hypothenar wasting
Weakened abduction and adduction of the finers - interossei muscles
Loss of sensation over little and ring finger and medial palmar surface

Question 2

How can damage to the ulnar nerve occur

Answer 2

Damage at the elbow

• dislocation or fracture of the elbow - particularly over medial epicondlye
• medial epicondylitis (golfers elbow)
• entrapment within the cubital tunnel of the elbow - may occur when patient sleep with arms flexed or in patients with OA of elbow and osetophyte compresses nerve

Damage at wrist
- laceration
- compression in guyons canal - ulnar tunnel syndrome. Can occur in cyclists who press the hook of hamate against the handlebars
can also be a complication of fracture of hook of hamate
- wrist fracture

Question 3

What is the ulnar paradox

Answer 3

A lesion higher up at the elbow will create a less prominent deformity then a lesion or injury at the wrist because damage at the elbow will dennervate Flexor Digitorum Profundus therefore flexion at the IP joint weakened

Question 4

What are the differentials for damage to the ulnar nerve

Answer 4

Damage to the brachial plexus - klumpke palsy or pancoast tumour may be compressing brachial plexus
damage to cervical spine - spondylysis, OA, Spondylisthesis - can perform Spurlings test to confirm
Epicondylitis

Question 5

How would you investigate ulnar nerve damage

Answer 5

X-ray of wrist, forearm and elbow = look for any fractures, osteophytes that are compressing ulnar nerve
X-rays of neck, shoulder and chest may be needed
nerve conduction tests to confirm area of entrapment

Question 6

How is ulnar nerve damage treated

Answer 6

CONSERVATIVE

• anterior elbow splinting
• NSAIDs

Cubital tunnel syndrome
- Surgical decompression of tunnel

Ulnar tunnel syndrome
- surgical decompression of tunnel

Question 7

How would you elicit median nerve damage

Answer 7

Ask patient to make a fist and only the ring and little fingers curl - hand of benediction

Question 8

Why does the hand of benediction occur in median nerve damage

Answer 8

Flexor digitorum superficialis and flexor digitorum profundus lose innervation
so loss of flexion at MCP and IP joints

Question 9

How can you test FDS

Answer 9

Ask patient to rest dorsum of hand on table with fingers extended
hold all the ingers down apart from the middle finger and ask them the flex their middle finger

Question 10

How can you test for FDP

Answer 10

ask the patient to rest the dorsum of their hand on the table
hold the finger to be tested at the middle phalanx to stablise the PIP joint and ask them to bend the tip of their finger

Question 11

Which muscles does the median nerve innervate?

Answer 11

Lateral lumbricals
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis

Question 12

Which movements are lost in median nerve damage

Answer 12

loss of flexion at the MCP joints and IP of the index and middle finger
loss of opposition, abduction and flexion of the thumb
Leads to wasting of thenar eminence

Question 13

What is carpal tunnel syndrome

Answer 13

Compression of the median nerve within the carpal tunnel leading to paraesthesia or the lateral palmar surface and lateral 2.5 fingers
wasting of the thenar eminence
weakness of grip and difficulty opposing thumb

Question 14

What are the causes of carpal tunnel syndrome

Answer 14

MEDIAN TRAP
Myxoedema 
Edema
Diabetes mellitus
Idiopathic 
Acromegaly 
Neoplasm 

Trauma - wrist fracture
Rheumatoid Arthritis
Pregnancy

Question 15

How is carpal tunnel syndrome investigated

Answer 15

Positive phalens test - flex wrist for 30 secs and hand starts tingling
Positive Tinels test - percuss carpal tunnel causes paraesthesia and pain
Nerve conduction studies
USS

Question 16

How do you treat carpal tunnel syndrome

Answer 16

Rest 
Splint
NSAIDs
injected corticosteroids 
Surgery - flexor retinaculum decompression

Question 17

How will radial nerve damage present

Answer 17

Wrist drop
extensors of the wrist will stop working if damage at the elbow or above
Loss of sensation over dorsum of hand and posterior forearm

Question 18

How can damage to the radial nerve occur

Answer 18

Entrapment between heads of muscles - passes through brachialis and brachioradialis –> tendonitis can lead to impingement
Fracture to the shaft of the humerus - radial nerve runs up radial groove on posterior humerus
Dislocation of the humerus
Trauma/compression to axilla or brachial plexus
- compression due to crutches
damage this high will lead to loss of function of triceps –> poor elbow extension

Question 19

What is dupuytrens contracture

Answer 19

Fibromatosis of the palmar fascia leading to fixed flexion deformities of the flexor tendons in the hand
One or more fingers will be pulled into flexion at the MCP joint or PIP joint

Question 20

What are some of the risk factors associated with duputryens contrature

Answer 20

Alcoholic liver disease
Manual labour
Phenytoin treatment
Trauma to the hand

Question 21

What is the treatment for dupuytrens contracture

Answer 21

Full fasciotomy and skin graft if interphalangeal joints affected - tends to be worse. Skin graft needed because the skin may tighten after fasciotomy
Needle fasciotomy can be used to treat a contracture at the metacarpophalangeal joints

Question 22

What is trigger finger

Answer 22

Finger may stick/lock in a flexed position when trying to extend.
Occurs when the tendon becomes stuck while sliding under the tendon sheath - flexor tendon cannot relax –> finger unable to extend

Question 23

What is the treatment for trigger finger

Answer 23

May go away on its own - if due to inflammation, steroid injections can be given to get rid of inflammation
Splinting - straighten the finger for long periods of time e.g. whilst sleeping
Surgery - to widen the tendon sheath, stopping the tendon from getting stuck

Question 24

What can removal of the trapezium help with

Answer 24

OA of the thumb - reduces pain

Question 25

What are the side effects of having a trapeziectomy

Answer 25

Shortening of the thumb
Reduction in pinch strength
However movement of the thumb is preserved

Question 26

What is the common causes of scaphoid fracture

Answer 26

Fall on a outstretched hand

Question 27

How does a scaphoid fracture present

Answer 27

Pain at base of thumb
Fell onto outstretched hand
Pain worse on pressing at the anatomical snuffbox or palm or telescoping the thumb towards the trapezium and scaphoid

Question 28

How is a scaphoid fracture investigated

Answer 28

X-ray of hand - may not sow fracture initially. Book outpatients xray for 2 weeks time when bone resorption may have taken place – more obvious #

Question 29

What are the complications of a scaphoid fracture

Answer 29

Avascular necrosis of the proximal pole because the scaphoid has a distal to proximal supply

Question 30

What is a Galaezzi fracture

Answer 30

fracture of distal 1/3 of radius and dislocation of the radio-ulnar joint

Question 31

How do galaezzi fractures occur

Answer 31

FOOSH

more commonin children

Question 32

How do you treat galaezzi fractures

Answer 32

open reduction and internal fixation

Question 33

What is a monteggia fracture and dislocation

Answer 33

fracture of ulnar shaft with associated dislocation of the radial head at the capitulum
(typically FOOSH)