MSK Flashcards
Arms: Nerves Blood vessels Dislocations Hand nerves and tendons
Sensations lost in order in nerve compression
Light tough, pressure and vibration
Then pain and temperature
Causes of nerve compression in arm - 5 categories
Anatomical - fracture deformity, synovial fibrosis
Systemic - alcohol, diabetes, renal failure, Reynaud’s
Inflammatory - RA, infection, tenosynovitis
Mass - haematoma, lipoma
Fluid imbalance - pregnancy, obesity
Pathophysiology of nerve compression
Microvascular compression causes intraneural oedema which increases it
Increases pressure and vibratory threshold
Fibrosis, axonal loss, demyelination cause weakness or paralysis of motor nerve
Other signs and tests of nerve compression except motor and sensory - 4
2 point discrimation (>6mm = abnormal)
Skin - colour, temperature from SNS dysfunction
Electromyography
Nerve conduction studies
RF for carpal tunnel
MEDIAN TRAP: Myxoedema oEdema Diabetes Iatrogenic Acromegaly Neoplasm Trauma RA Amyloidosis Pregnancy
What is in carpal tunnel
Median nerve
Flexor pollicis longus tendon
4 FDS tendons
4 FDP tendons
Pathogenesis of carpal tunnel syndrome
Pressure increases
Epineural blood flow decreases and nerve becomes oedematous
Increasing pressure causes nerve conduction to decrease
Sx of carpal tunnel and tests
Paraesthesia and pain often at night on volar aspect of radial 3.5 digits
Tinel and Phalen
Loss of fine motor control and weakness = late
Nerve conduction test and EMG
Differentials for carpal tunnel syndrome
Cervical radiculopathy
Thoracic outlet syndrome
Peripheral neuropathies eg diabetess
Treatment of carpal tunnel
Activity modification, night splint, NSAIDS
Single corticosteroid injection
Operative release
Complications of surgery for carpal tunnel - 2
Ulnar neurovascular structures in Guyon canal can be injured if too ulnar
Damage to recurrent motor branch of median nerve if too radial
Where to find recurrent motor branch of median nerve
Kaplan line (from abducted thumb distal surface) and longitudinal line from web spaces of index and middle finger
Differentiate pronator syndrome and CTS
Pronator has forearm pain and palmar cutaneous median nerve sensory pain
What is the cubical tunnel
Floor = elbow joint capsule and MCL Sides = olecrattnon and median epicondylitis Roof = FCU fascia and fibrous band
Compression of ulnar nerve at medial epicondyle
Paralyse FCU, 1/2 FDP, interossei and medial 2 lumbricals
No abduction or adduction
4th and 5th digits reduced movement
1/2 4th and 5th digits no sensation
Compression of ulnar nerve at wrist
Paralyse medial 2 lumbricals and interossei
No finger abduction/adduction
Ulnar claw: cannot extend at IPs of 4th and 5th digits (unopposed flexor digitorum), but overextension at MCP (unopposed extensor digitorum)
Test for ulnar nerve
Froment’s test - paper between thumb and finger, pulling out causes thumb to flex as flexor pollicis is used to make up for lack of adductor pollicis
Nerve damage in axilla?
Radial = paralyse triceps and posterior forearm, so no wrist extension, no cutaneous innervation
Nerve damage in radial groove?
Radial nerve - paralyse posterior forearm - wrist drop, no dorsum cutaneous innervation
Posterior forearm paralysis but no wrist drop
Deep motor branch of radial nerve injury after elbow, paralysing post forearm except ECRL and supinator
Median nerve damage at elbow
Paralyse anterior forearm except FCU and 1/2 FDP
No pronation
Weak flexion
Hand of Benediction when make fist: cannot flex MCP or extend IPs (1-3)
Sensory loss of lateral 1/2 of hand
Median nerve damage at wrist
Paralyse thenar muscles and lateral 2 lumbricals
Hand of benediction and sensory loss of lateral 1/2 hand
Nerve damage on shoulder dislocation
Axillary nerve Paralyse deltoid and teres minor No abduction Can feel greater tuberosity Loss of regimental badge sensation
Nerve damage causing weakness of arm movements?
Musculocutaneous at axilla: - weak shoulder flexion from pec major - weak elbow flexion from brachioradialis - weak supination from supinator Lateral forearm sensory loss
Damage to nerves at birth
C5-6 = Erb’s palsy = dorsum of hand forward, weakened movement to touch shoulder T1 = Klumpke = ulnar and medial nerve damage = hand muscles paralysed, to claw with hyperexension at MCPs, median sensory loss on arm
Nerve damage in cervical node biopsy?
Axillary - trapezius, partial SCM weakness
Long thoracic nerve damage and how?
Serratus anterior = winged scapula, no abduction >90 degrees
Vulnerable as superficial
Cause of no abduction >90 degrees
Long thoracic damage = serratus anterior
Surgery to inferior axilla/breast nerve complications
Thoracodorsal (C6-8) = cannot raise trunk with arm
Which nerves wraps around humerus?
Radial nerve
Which nerve goes behind median epicondyle?
Ulnar nerve
3 types of nerve injury
- Neuropraxia - nerve stretch
- Axonotmesis - incomplete nerve injury, Wallerian degeneration
- Neurotmesis - complete nerve injury, wallerian degeneration, worst prognosis
4 signs of severe brachial plexus injury
Global motor dysfunction
Complete sensory loss
Neuropathic pain
Horner’s syndrome
2 associated problems with brachial plexus injury
Paralysed hemidiaphram - insp and exp chest X-ray
Root avulsion could have transverse spinal process fracture
What is cerebral palsy
Non progressive CNS injury
MSK upper limb features of cerebral palsy - 6
Thumb in palm Clenched fist Wrist flexion Forearm pronation Elbow flexion Shoulder internal rotation
Manage cerebral palsy
Physio and nighttime splint
Diazepam, baclofen for antispasticity
Botulinum injection
Surgery
Median nerve anatomy
C5-T1, lateral and medial cords of brachial plexus
Medial to brachial artery in antecubital fossa
Anterior interosseus branch (motor to FPL, FDP, index finger and pronator quadratus) distal to elbow
Palmar cutaneous branch proximal to wrist
Recurrent motor branch to thenar muscles at end of carpal tunnel
Motor to pronator teres, palmaris longus, FCR, FDS, LOAF
Sensory to radial 3.5 digits
Nerve injury on lateral knee injury
L4-S2 - common peroneal neve/lateral popliteal nerve
Cannot dorsiflex foot and toes
Sensory loss on dorsum of foot
Tibial nerve injury
Calcaneovalgus foot
Cannot stand on tiptoe or invert foot
Sensory loss on sole
Nerve injury from proximal fibular fracture
Common peroneal nerve compression - cannot dorsiflex foot, lose sensation over dorsum
Where is the brachial plexus?
Vertebral column between scalene and anterior muscles
Divisions under clavicle, medial to coracoid process
Follows subclavian then axillary artery
Damage to brachial plexus - 5
Trauma: Direct - fracture or penetration injury Indirect - avulsion/traction, neck stretching at birth Tumours - pancoast Radiation Neuropathy
Nerves and muscles damaged in Erb’s palsy
Suprascapular, musculocutaneous, axillary nerves
Supraspinatus and deltoid - abduction
Infraspinatus and teres minor - external rotation
Biceps - supination
Brachialis - elbow flexion
Arterial supply of hand
Superficial palmar arch - mainly ulnar
Deep palmar arch - mainly radial, plus princeps pollicis artery to thumb
Most common vessel disease in hands
Small vessel occlusive disease in connective tissue disease eg scleroderma, SLE, RA
Difference between Raynaud disease and phenomeon
Disease - younger, no underlying disease, no trophic findings (ulcer, ganrene), symmetrical
Phenomenon - identified underlying diseae, rapid progression, older, trophic findings, asymmetrical, abnormal inv
Manage raynaud disease
Calcium channel blockers for temporary relief
Quit smoking
Avoid cold
Compartments in forearm
Mobile wad - brachioradialis, extensor carpi radialis longus and brevis
Dorsal
Volar
What is Volkmann ischaemic contracture
Untreated compartment syndrome - muscle fibrosis and myonecrosis - FDP and FPL
Vessel supply of anterior and posterior arm compartments
Anterior - brachial artery
Posterior - brofunda brachii artery
Where do vessels leave the vertebrae
Foramen transversum
Joint between vertebrae
Zygopophyseal joint
Ligaments in spine - 6
Anterior and posterior longitudinal ligaments Intertransverse Interspinous Supraspinous and nuchal Ligamentum flavum
What makes up intervertebral disc
Annulus fibrosis - concentric rings of lamellae of fibrocartilage on epiphyseal rims
Nucleus pulposus in middle - 85% water and proteoglycans
Cartilage plate on top
Vessel supply of intervertebral disc
Avascular - nourished by diffusion from BV at periphery of annulus and vertebral body
Ascending spinal tracts - 6
Spinothalamic - ventral and lateral
Spinocerebellar - ventral and dorsal
Fasciculus gracilis and cuneatus
Descending spinal tracts - 5
Lateral corticospinal Ruprospinal Vestibulospinal Tectospinal Venttral corticospinal
2 types of spina bifida
Occulta - laminae of L5-S1 don’t develop and fuse properly, concealed by skin and tuft of hair
Cystica - one or more arches fail to develop, causing herniation of meninges (meningocoele) or meninges and cord (meningomyelocoele) - causes limb/bladder/bowel paralysis
Vertebrae dislocation?
Cervical - large canal, limited cord damage, slips back into place unless ‘facet jumping’ where displaced articular process locks
Thoracic and lumbar have interlocking articular processes so unlikely
Subluxation of lumbar vertebrae = spondylolisthesis in adolescence from abnormal pars interarticularis
Complications of whiplash? - 3
Tear/stretch anterior ligament
Injure posterior parts eg vertebral arches and processes
Pinch C1 between C2 and occipital bone
Rupture anterior long lig and annulus fibrosis of C2/3 = death
Sx of whiplash - 4
Occipital headache
Tinnitus
TMJ pain
Migraine sx in eyes
Vertebrae most likely to fracture
T11 and T12 where transition from inflexible thoracic to mobile lumbar
How does a laminectomy work?
Excise spinous process and laminae, or pedicles to access canal
Relieve cord or roots from tumour, herniated disc or bony hypertrophy
What is lumbar spine stenosis?
Narrow vertebral canal compresses nerve root and makes disc herniation more likely
Made worse by arthritic changes and ligamentous degeneration in elderly
Sx of lumbar spine stenosis
Positional back pain - better leaning forward
Lower limb pain on walking/weight bearing
4 age related changes to discs and vertebrae
Vertebrae: reduced bone density and strength causing increasingly concave vertebrae
Discs: reduced water, proteoglycans and elastin, with increased collagen
Annulus: lamellae thicken, fissures and cavities
Pressure increases on edge of bodies where discs attach causing osteophytes
Herniation of nucleus pulposus - where and sx
Posterolateral as no longitudinal ligaments and thinnest. Proximal to spinal nerve roots
Sx - local pain if pressure on ligaments and annulus, and local inflammation from rupture of nucleus
Nerve roots immediately and below are affected
Rupture of transverse ligaments of atlas
Releases dens, causing atlanto-axial subluxation/incomplete dislocation
Dens drives into medulla of brainstem = death
Or drives into cervical region of cord = quadriplegia
Ligament more likely to rupture related to axis/atlas
Alar ligaments - thinner than transverse ligament. Attach axis to occiput.
Flex and rotate can cause rupture, allowing increased range of movement
Layers gone through for LP
Ligamentum flava, dura, arachnoid
Into lumbar cisterna
Spinal cord ischaemia - 4 causes
From disruption of spinal and medullary arteries in fracture or dislocation
Obstructive artery disease in great anterior segmental medullary artery of adamkiewitz
Aortic clamping in surgery
AAA
What is spinal shock?
Transient physiological reflexive depression of spinal cord function below level of injury, with sensorimotor loss
Features: hypotension, sweating, bradycardia, hypothermia, flaccid, areflexic, incontinence, priapism, may have perineum spared
Bulbocavernosus reflex returns in 24-48h
Bad sign in spinal shock
Spasticity developing
What is neurogenic shock
Acute spinal cord injury with hypotension and bradycardic
Causes circulatory collapse from lack of sympathetic tone causing reduced vascular resistance and pooling of blood in extremities
Cord transection at C4-5
Quadriplegia
Can breathe
Cord transenction at T1-9
Paraplegia
Variable trunk function
Cord transection at T10-L1
Some thigh function
Nerves affected in cauda equina syndrome
L1-S5
SNS: hypogastric plexus
PSNS: inferior hypogastric plexus and pelvic splanchnic nerve
Pudendal nerve
6 causes of cauda equina
Tumour Disc herniation Haematoma Stenosis Abscess Trauma
4 sx of cauda equina
- Lower extremity sensorimotor loss
- Neurogenic bladder = overflow incontinence
- Bilateral leg pain
- Saddle anaesthesia
Medical treatment for cauda equina - 2
Vasodilator treatment prostaglandins to prevent ischaemia and reduce pain
Antibiotics if infection
Immediate cauda equina manageent
MRI and CT myelography
Surgical decompression within 48h
What is central cord syndrome and what is it caused by
Elderly people, extension injury with osteophytes
Selective destruction of lateral corticospinal tract and white matter, causing LMN signs in arms as more central and UMN in lower limbs
Recovers distal - proximal
What is anterior cord syndrome
Flexion or compression injury
Causes motor and sensory deficit below injury - pain, temperature, motor
Proprioception and vibration preserved
What is hemisection of cord?
Brown-Sequard syndrome:
Ipsilateral loss of dorsal column and lateral corticospinal
Contralateral loss of lateral spinothalamic at spinal level
Where and what is spinal epidural abscess?
Pus or inflammatory granulation tissue between dura and adipose
RF for spinal epidural abscess - 4
Recent spinal procedure
Immunodeficiency
PWID
>60y
Cause of spinal epidural abscess
Haematogenous or discitis
Staph a, gr neg E. coli, pseudomonas
Sx of spinal epidural abscess - 4
Systemic sx
Pain
Neuro signs - radiculopathy or myelopathy
Paralysis
Management of spinal epidural abscess
CT myelogram or MRI
Brace and IV abx
Surgical decompression and stabilisation
Neuro sx of TB
Abscess, granulation or caseous tissue
Subluxation/dislocation
Ossify ligamentum flavum in kyphosis causes stenosis
Destruction that may be seen on CT for spinal TB - 4
Fragmentation
Osteolysis
Subperiosteal
Sclerotic
MRI for TB?
With gadolinium contrast: Smooth walled abscess breaching epidural space End plate disruption Paravertebral soft issue shadowing Cord oedema or atrophy
Manage spinal TB
Drugs
Orthosis
Decompression/stabilisation
What is a spinal degeneration condition
Spondylosis Degeneration of disc and 4 joints including facets Causes nerve compression - radiculopathy Disc herniation Central stenosis Myelopathy
What is cervical stenosis and 2 causes
Congenital or acquired - trauma, degeneration
Absolute = canal diameter <10mm, relative = 10-13mm
Increases risk of radiculopathy or myelopathy from minor trauma
Very common condition >50yo with no ankylosis or erosion, and associated condition
Diffuse Idiopathic Skeletal Hyperostosis:
Syndesmophytes form in 4+ consecutive levels of ligaments
With enthesopathy of shoulder, elbow, hip, knee, calcaneus
Features of DISH - 3 categories
Back - lumbar spine stenosis, mild chronic back pain, morning or cold stiffness
Throat - hoarse, stridor, dysphagia, sleep apnoea
Sx - reduced ROM, stenosis/myelopathy sx
Manage DISH - 4
NSAIDs Bisphosphonates Physio Cervical traction Brace Decompression and stabilisation
Pathophysiology of Ankylosing spondylitis and 3 joints affected
Enthesis inflammation causes erosion and soft tissue ossification, and joint ankylosis
Of sacroiliac, spinal apophyseal and pubic symphysis
Annulus inflammation makes bridging syndesmophytes
MSK features of Ank spond and 2 tests
Pain and stiffness, sciatica, SOB Kyphosis Hip flexion contracture Faber test - pain on flexion, abduction and external rotation of hip Schober test
Manage Ank spond
NSAIDs, COX2 inhibitor
Physio
TNFa blockers eg infliximab
Most common direction of shoulder dislocation
Anterior or anteroinferior
Sign and image for shoulder dislocation
Apprehension sign
Painful and unilateral
Axillary view diagnostic
Treat shoulder dislocation
Reduction and sling
Then rotator cuff strengthening
associated injuries with shoulder dislocation
Bankart lesion: anterior tear of glenoid labral (makes recurrence likely)
Hill-Sachs lesion: indentation in humeral head from hitting on labrum
Shoulder dislocation posterior - when?
Associated with seizures and electrical shock
Seen on axillary view
May have fracture of lesser tuberosity or reverse Hill-Sachs
What is Dupuyren’s contracture?
Benign fibroproliferative disorder. Nodule in palmar fascia then forms diseased cords and digital flexion contractures
5 causes of Dupuytren’s contracture
Alcohol and tobacco Diabetes Epilepsy COPD Familial
What is a ganglion on hand and where
Normally on dorsum of wrist
Firm and well circumscribed
Joint or tendon sheath fluid
Benign bone tumours - 4
Chondroma
Osteochondroma
Osteoid osteoma
Fibrous dysplasia of bone
What is chrondoma of bone and what is treatment
Benign cartilaginous swelling from surface of bone or medulla
Pain and increased fracture risk
Exclude malignancy, rarely need treatmen
What is fibrous dysplasia of bone and treatment
Developmental abnormality where bone is not properly formed
Pain and increased fracture risk
Treat with surgical stabilisation
Bisphosphonates can ease symptoms
What is osteoid osteoma, investigation findings and treatment
Benign bone lesion in long bones or spine of males 10-25yo
X-ray = local cortical sclerosis with radiolucent central nidus, which may have central area of calcification
Nidus releases prostaglandins so pain unreleased to activity and relieved by ibuprofen
Manage: CT-guided biopsy and radiofrequency ablation. May be missed on X-ray
What is osteochondroma, investigate and management
Commonest benign bone tumour
Painful mass in proximal humerus or femur, or around knee as a result of trauma
X-ray = bone spur
Remove if causing symptoms eg pressure on adjacent structures or still growing after skeletal maturity, as can become malignant
Bone sarcoma presentation - 4
Non-mechanical bone or joint pain
Bone pain at night
Bony swelling
Pathological fractures
5 tumours which spread to bone
Prostate Thyroid Lung Kidney Breast
Where do bone tumours metastasise to
Haematogenously to lens or other bones
Staging of bone tumours
MRI or PET-CT
Most common primary malignant bone tumour and sign on imaging
Multiple myeloma
Multiple punched out osteolytic lesions
Osteosarcoma - where and who
10-20yo with peak in growth spurt
In metaphysis of long bones and around knee
Secondary causes = irradiation or Paget’s disease
Osteosarcoma on imaging - 2
Bony destruction and new formation - sunray spiculation
Periosteum elevation - codman’s triangle
Sx of osteosarcoma
Pain before mass
Inv osteosarcoma spread
MRI of area for intramedullary spread
High resolution CT chest for pulmonary mets, especially if raised ALP
Manage osteosarcoma
Neoadjuvant chemo and amputation
Most will have micrometastatic disease at diagnosis
4 radiological features of Ewing’s sarcoma
Bone destruction
New bone formation in concentric layers - onion ring sign
Elevated area of periosteum - codman’s triangle
Soft tissue swelling
What is Ewing’s sarcoma and management
Malignant round cell tumour of long bones (diaphysis) and limb girdle
Adolescents
Often have chromosomal translocation
Treat: chemo, RT, surgery
What is bone tumour of middle aged people? Treatment
Chondrosarcoma - may be de novo or malignant change from chondroma
On axial skeleton
X-ray shows popcorn calcification
Excise. CRT no effect
Sarcoma vs carcinoma?
Sarcoma = malignant neoplasm from mesenchymal cells (connective tissue and non-epithelial tissue): 1. Soft tissues, 2: Primary bone, 3. GI stromal tumour Carcinoma = from epithelial cells - breast, bowel, lung
What are soft tissue sarcomas and different types
Any tumour from mesenchyme - fat or muscle etc
Painless enlarging mass
Fibrosarcoma, leiomyosarcoma, liposarcoma, rhabdomyosarcoma (kids)
When to suspect soft tissue sarcoma - 4
> 5cm
Growing
Deep to deep fascia
Painful
Manage soft tissue sarcoma
MRI then needle biopsy
Gene expression to improve diagnosis and indicate if chemo will be effective
Excise and radiotherapy
