Hand and wrist Flashcards
How will a patient present who has damaged their ulnar nerve
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
How can damage to the ulnar nerve occur
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
What is the ulnar paradox
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
What are the differentials for damage to the ulnar nerve
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
How would you investigate ulnar nerve damage
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
How is ulnar nerve damage treated
CONSERVATIVE
- anterior elbow splinting
- NSAIDs
Cubital tunnel syndrome
- Surgical decompression of tunnel
Ulnar tunnel syndrome
- surgical decompression of tunnel
How would you elicit median nerve damage
Ask patient to make a fist and only the ring and little fingers curl - hand of benediction
Why does the hand of benediction occur in median nerve damage
Flexor digitorum superficialis and flexor digitorum profundus lose innervation
so loss of flexion at MCP and IP joints
How can you test FDS
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
How can you test for FDP
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
Which muscles does the median nerve innervate?
Lateral lumbricals
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
Which movements are lost in median nerve damage
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
What is carpal tunnel syndrome
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
What are the causes of carpal tunnel syndrome
MEDIAN TRAP Myxoedema Edema Diabetes mellitus Idiopathic Acromegaly Neoplasm
Trauma - wrist fracture
Rheumatoid Arthritis
Pregnancy
How is carpal tunnel syndrome investigated
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
How do you treat carpal tunnel syndrome
Rest Splint NSAIDs injected corticosteroids Surgery - flexor retinaculum decompression
How will radial nerve damage present
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
How can damage to the radial nerve occur
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
What is dupuytrens contracture
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
What are some of the risk factors associated with duputryens contrature
Alcoholic liver disease
Manual labour
Phenytoin treatment
Trauma to the hand
What is the treatment for dupuytrens contracture
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
What is trigger finger
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
What is the treatment for trigger finger
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
What can removal of the trapezium help with
OA of the thumb - reduces pain
