Ulnar nerve and Dupuytrens Flashcards
Sensory nerve supply to hand - draw it
Remember median comes over fingers
What does this image show?
Dorsal interossei wasting - supplied by ulnar nerve
Muscles supplied by ulnar nerve in hand
All apart from LOAF =
* Adductor pollucis
* Opponens digiti minimi
* Flexor digiti minimi
* Abductor digiti minimi
AND
* Medial (ulnar) two lumbricles
* Palmer interossei
* Dorsal interossei
All For One And One For All
Nerve root value brachial plexus
- Musculocutaneous - C5, C6, C7
- Radial - C5, C6, C7, C8, T1
- Axillary - C5, C6
- Ulnar - C8, T1
- Median - C5, C6, C7, C8, T1
3 muscketerrs, 2 assaniated by 5 rats, 5 mice and 2 unicorns
What is Froment’s test?
- Test adductor pollucis of thumb
- Supplied by ulnar nerve
- Hold paper between thumb and index finger
- Examiner tries to pull paper
- Positive test = compensation by contracting flexor pollucis longus = flexed thumb
- = ulnar nerve injury
Where is entrapment most likely to occur of ulnar nerve?
- Cubital tunnel at elbow
- OR Guyons canal at wrist
Investigation to confirm ulnar nerve entrapment
Nerve conduction studies
Patho-anatomy of ulnar claw hand
- Lumbricles 3+4 (medial/ulnar) are paralysed due to ulnar nerve entrapment
- These usually flex at MCPJs and extend IPJs
- = MCPJs have unapposed extension by extensor digitorum
- = IPJs have unapposed flexion from FDP and FDS
- Extensor digitorum cannot appose FDS and FDP as energy is dissipated at MCPJ
FDP/S - flexor digitorum profundus and superficialis
Treatment for ulnar nerve entrapment/cubital tunnel syndrome
- Avoid exacerabting acitivites
- Physio
- Steroid injections
- Splint at night
- Surgery if resistent - ulnar nerve release by cutting away tight tissue
Risk factors for Dupuytrens contracture
- Male
- Smoker
- Increasing age
- FH of condition
- Northern european
- Occupational - heavy manual work or vibrating tools
Other diseases associated with Dupuytrens contracture
- HIV
- Vascular disease
- Diabetes
- Alcoholic liver cirrhosis
- Hypercholesterolaemia
Cells that cause Dupuytrens
Fibroblasts
Risk of surgical correction of Dupuytrens
- 66% have post of recurrence
- Digital nerve injury
- Digital blood vessel injury
- Infection
- Stiffness
- Loss of finger
Patho phys of Dupuytrens
- Fibroblastic hyperplasia
- Altered collagen matrix
- = thickening and contraction of palmar fascia
Disease progression of Dupuytrens
- Pitting and thickening of palmar skin, loss of mobility of overlying skin
- Firm, painless nodule appears - fixed to skin and deeper fascia, increasing in size
- Cord then develops - resembles tendon, contracts over months-years
- Contraction of cord pulls on MCPJ and PIPJ = flexion deformity in fingers
Test for Dupuytrens
- Huestons test
- If patient unable to lay palm flat on tabletop = +ve
Differentials for dupuytrens
- Stenosing tenosynovitis - painful and overuse/trauma
- Ulnar nerve palsy - reduced movement and sensation
- Trigger finger - nodule with finger motion
Investigations Dupuytrens
- Clinical diagnosis
- BUT should have routine bloods to assess for RF eg:
- HbA1C
- LFT
- Can do USS for accuracy in applying intralesional injections
Management for Dupuytrens
- Depends on stage
- No functional disability = monitor and conservative
- Functional disability/rapidly progressive = surgery
Conservative management Dupuytrens
- Hand therapy - stretches
- Injectable collagenase clostridium histolyticum - good for early disease
Surgery for Dupuytrens
Excision diseased fascia - fasciectomy. Either:
* Regional - entire cord removed
* Segmental - short segments of cord removed
* Dermofasciectomy - cord and overlying skin removed followed by skin graft
* Closed - good for those unsuitable for major surgery, percutaenous with LA
* Finger amputation - rarely needed
When is surgery indicated for Dupuytrens?
- Functional impairment
- MCP contracture >30 degrees
- Any PIP contracture
- Rapidly progressive disease
