MSK Flashcards
What are the types of bone tumours?
Metastatic disease
Primary bone tumours
Benign
Haematological
Soft tissue bone tumours
Which cancers most likely metastasise to bone?
BLT KP Breast Lung Thyroid-TFTs Kidney-U&E, Ca2+ and Phosphate Prostate-PSA and DRE
What could be seen on x-ray of bone malignancy?
- Locatoion Epiphysis? Metaphysis? Diaphysis? - Size - Lytic or scleroitic? Sclerotic: prostate as increased osteoclast action Lytic: Lung, Kdney and Thyroid Breast is mixed - Zone of transition Narrow: slow-growing tumours have well defined demarcated sclerotic margin Wide: tumour grows too fast for bone to respond-looks moth-eaten - Periosteal reaction? - Soft tissue involvement?
What are the primary bone sarcomas?
Bone-forming tumours Cartilage forming tumours Giant-cell tumour Marrow tumour Vascular tumours CT tumours
What are the characteristics of malignant bone tumours?
Poorly defined borders
Wide zone transition
Moth eaten pattern of bone destruction
Periosteum shows interrupted sunburst or onion skin reaction
Adjacent soft tissue mass
What are the characteristics of benign bone tumours?
Well-defined sclerotic borders
Geographic bone destruction
Periosteal reation is uninterrupted (solid)
No soft tissue mass
What is osteosarcoma?
Malignancy of osteoblasts producing osteoid (immature bone)
Aggressive
Often at end of long bones e.g. the knee
Pain and swelling, may be reluctant to bear weight
Males > females
Teenagers
Paget’s disease
MCC primary bone cancer
Chemo/Radio/Resect
What is Ewing’s sarcoma?
Malignant small, round, blue cell tumour of neural tube
Mixed lysis and sclerosis
Pariosteal reaction with lamellated bone growth
Genetic
Fevers, anaemia, systemic illness
May mimic osteomyelitis
55% in axial skeletonPelvis, femur, humerus, ribs and claical and spine
- Spine stenosis, back pain and cauda equina
Teenagers 10-20
Males>females
Chemo/Radio/Surgery
What is chondrosarcoma?
Cancer of cartilage producing cells.
Any age-middle and olver
Axial skeleton, pelvis and proximal femur
Xray shows invasion and soft tissue extension
Back or thigh pain, sciatic, bladder problems
Surgical resection (C&R not effective)
What is osteochondroma?
MC benign tumour of bone
Cartilage-capped boney projections
Remove if iminging on vessles or nerves and affecting movement
Define: sarcoma
Cancer arising from transformed cells fo mesenchymal origin e.g. cancellous bone, cartilage, fat, muscle, vessles or haemopoetic tissue
What may a mid-humeral shaft fracture damage?
Radial nerve in the radial groove
Reduced sensation of the dorsal hand and extensor disfunction
Which carpal bone dislocates most commonly?
Lunate bone dislocates anteriorly into the carpal tunnel and compresses the median nerve resulting in wrist pain and altered sesnation in the palmar aspect of the lateral fingers and weakness in thumb opposition
Describe a Hamate fracture
Usually the hook
Foosh
Damage to the ulnar nerve - claw hand
Describe an Ulnar Collateral Ligament tear
‘Skier’s thumb’
Tearing: pain along ulnar side of the MCP thumb joint
Laxity: ‘gamekeeper’s thumb’
What are the risk factors for AVN of the femoral hip?
Chronic corticosteroids
Alcohol
SLE
Not many xray changes
What is Septic Arthritis?
Pain at rest and movement
Joint (unilateral) tenderness and swelling
Fevere
Systemic problems
Xray: joint effusion
Osteoporosis
Osteopenia: reduced bone mass but ratio of bone mineral to matrix is normal
Poor diet
Low oestrogen
Normal levels of calcium, phosphat, PTH and ALP
Treat with bisphosphonates
Osteomalacia
Decreased bone mineralisation so low mineral to matrix ratio
Insufficient Ca2+ due to low Vitamin D or increased phosphate loss in kidneys
Ca2+ low
Vitamin D low
Phosphate high
ALP high
Diffuse pain particularly femur, pelvis and spine
Bone bowing and difficulty walking
What is Hammer toe?
Flexion and PIJ and Extension at DIJ in 2nd 3rd 4th toes
Can be rigid or flexible
Supracondylar humeral fractures
Damage
What is Compartment syndrome?
Pressure build up in a closed space (compartment) causing severe pain
What causes Compartment Syndrome?
Fluid in the compartment
- Blood in trauma
- Pus in infection
Trauma- long bone especially
- Fractures
- Crush
- Haematoma
Burns Infection Prolonged compression Muscle hypertrophy e.g. athletes Severe ascites
How does Compartment syndrome present?
Early:
- Burning, deep and aching PAIN, builds as pressure increases
- Worsened by passive stretching of muscles
- Paraesthesia
- Swelling of compartment
Late: - Loss of distal Pulses (cap refill reduced) - Ischaemia: rest of 6 Ps Pallor Paralysis Perishingly cold
Where are the common sites for Compartment syndrome?
MC: Lower limb
Also
Forearm
Gluteal-sciatic nerve palsy
Abdomen: major organ injury
How is Compartment Syndrome investigated?
Intracompartmental pressure measurements
Wick catheters, pressure transducers, needle manometry, etc.
(Nasogastric tube can be used in abdominal compartment syndrome)
MRI may help in ambiguous cases
How is Compartment Syndrome managed?
urgent decompression to prevent ischaemia
- Remove casts/bandage
- Elevate the limb
Fasciotomy-skin and deep fascia are cut along length of compartment and left open until pressure is releived
Abx, analgesia, phsio after
What are the complications of Compartment Syndrome?
Tissue necrosis. In muscles this leads to fibrosis, shorteining, ischaemic contracture and reduced function
What structures may be affected in Anterior Lower Leg Compartment Syndrome?
Deep fibular Nerve
Anterior Tibial Artery
What structures may be affected in Superficial Posterior Lower Leg Compartment Syndrome?
Tibial nerve
What structures may be affected in Deep Posterior Lower Leg Compartment Syndrome?
Tibial nerve and vessels
Fibualr artery
What structures may be affected in Later Lower Leg Compartment Syndrome?
Deep and Superficial fibular nerves
What structures may be affected in Anterior (ventral) forearm Syndrome?
Median and ulnar nerves
Radial and ulnar arteries
What structures may be affected in Posterior (dorsal) forearm Compartment Syndrome?
Posterior Interosseus nerve (deep branch of radial)
What is Osteomyelitis?
Infection of bone marrow leading to bone destruction and necrosis
It can spread to cortex and periosteum (causes necrosis) via the Haversian canals
What are the causative organsims in Osteomyelitis?
Staph Aureus
H. Influenzae
Streps
Ceftreiaxone or penicillins
Vancomycin for MRSA
What are the risk factors for Osteomyelitis?
Trauma
- Open fracture
- Surgery
Prosthetics – more likely to become infected as bacteria can easily form a biofilm
Diabetes → ulcer formation → infection spread to exposed bone
IV drug abuse
Immunosuppression
Chronic steroid use
Tuberculosis
Sickle-cell anaemia
How does Osteomyelitis present?
Fever Tenderness over bone Imobility Pain, redness and swelling Joint pain when associated with Septic Arthritis
Back pain, worse at rest and nerve patterns of pain when in spine
What are the investigations for Osteomyelitis?
Bloods
MRI
Biopsy is definitive
XRAY:
- periosteal reaction and necrosis ~1 week later
- sequestrum-dead bone isolated from live bone by necrosis looks like a white circle with black ring
- involucrum:new layer of normal bone growth from periosteum
What are the depths of Osteomyelitis?
Medullary
Superficial – Localised to one area of cortex
Localised – Cortex breached, medulla infiltrated
Diffuse – Cortex breached, medulla infiltrated, cortex on the OTHER SIDE also breached
How is Osteomyelitis managed?
Depride and saline washout
Remove prosthesis
Bone graft or antibiotic implants
6 weeks of antibiotics
Hyperbaric O2 therapy if recurrent
What is Septic Arthritis?
invasion of a joint by an infectious agent resulting in joint inflammation
Most often in hip or knee
Pus in joints will erode the cartialge
How does Septic Arthritis present?
Rubor Tumor Calor Dolor Loss of function ESPECIALLY IF SYSTEMICALLY UNWELL
What are the causative organisms of Septic Arthritis?
Staph Aureus- Flucloxacillin or Clindamycin
MRSA-Vancomycin
May enter via Inocculation (directly) or blood stream
What are the risk factors for Septic Arthritis?
RA or OA
Joint prosthesis
Low socioeconomic status
IV drug abuse
Alcoholism
Diabetes
Puncture wound to the joint
- Traumatic
- Iatrogenic from surgery or injections such as steroids for arthritis relief
Cutaneous Ulcers
How is Septic Arthritis investigated?
Bloods
Synovial aspiration: gram stain and culture and check for Gout
MRSA swabs
MRI will show inflammation
How is Septic Arthritis manged?
Abx immediately
Surgical washout-2 incisions, one pump saline in other suck it out
Flush until all pus has gone
What is Kocher’s criteria?
Suspecting SA in children: NEWT Non weight bearing ESR >40, CRP >20 WCC >12 Temperatur >38.5
1 feature = 3%
2 = 40%
3 = 93%
4 = 99%
What are Newman’s 4 points?
Suspecting Septic Arthritis:
- Pathogen isolated from joint
- Pathogen isolated from blood in context of hot red joint
- Typical features and turbid joint fluid in context of previous Abx
- Post mortem
What is Paget’s disease of the bone?
Chronic excessive breakdown and formation of bone due to increased osteoclast and blast action which leads to remodelling
There is more bone but it is non-lamellar and so weaker
What causes Paget’s disease?
Genetic-AD
Viral
How does Paget’s disease present?
Often asymptomatic
RAISED ALP
Pathological fractures
- Non-mechanical bone pain
- Bone deformity
- Riased skin temp
Which bones are often affected by Paget’s disease?
Axial skeleton
Long bones and skull most often affected:
- Pelvis
- Lumbar spine
- Femur
- Tibia
- Skull
What are the complications of Paget’s disease?
- Increased risk of pathological fractures as weaker and highly vascular so risk of bleeding
What are the complications of Paget’s disease?
Increased risk of pathological fractures as weaker and highly vascular so risk of bleeding and increased TPR which can lead to heart failure
Bone deformities:
- Spine curvatures: hypohosis and spinal stenosis/nerve compression such as sciatica or Corda Equina
- Tibia bowing
- Frontal bossing of skull and increased head size: may cause deafness and tinnitus due to CN8 compression and/or ear ossicle remodelling
- Enlarged maxilla
Osteoarthritis if near a joint
How is Paget’s disease investigated?
Bone-specific ALP
(maybe raised caclium and phosphate)
X-ray:
- Osteolysis (lucency)
- Lots of bone
- V shape between healthy and diseased bone
- Cotton wool on skull
May biopsy to rule out malignancy
How is Paget’s disease managed?
Analgesia Monitor for osteosarcoma Walking aides Bisphosphonates Relieve nerve compression ALENDRONATE to reduce pain and deformity
What are the causes of pathological fractures?
Atypical locations or very low trauma
- Osteoporosis
- Osteomalacia
- Bone cancers and tumours
- Bone cysts
- Paget’s disease
What are the causes of pathological fractures?
Atypical locations or very low trauma
- Osteoporosis
- Osteomalacia
- Bone cancers and tumours
- Bone cysts
- Paget’s disease
How can Myeloma be detected?
Bence-Jones proteins
How are bone-cancers managed?
Debarking: removal of metaplastic soft tissue from around bone
Chemo and radio
Replace joint if near joint
Prophylactic fixation: Mirel’s scoring system
Bisphosphonates reduce weakening
What antibiotics are used prohpylactically in surgeru?
Leicester uses 1.2g of co-amoxiclav on induction followed by 600mg over 8 hours post-op and then 600mg over 16 hours post-op
Teicoplanin is easier-one dose on induction
Swab for MRSA
What antibiotics are given for Open Fractures?
1.2g co-amoxiclav on A&E presentation
Or clandamycin/cefuroxamime
What are the antibiotics given for Bite Wounds?
Debride and leave in sterile dressing rather than close
Tetanus risk
Swab the wound
Dog Bites: Pasturella, strep, staph and Neisseria
Cat Bites:
Human bites:
Give co-amoxiclav 5 days OR doxycycline + metronidazole if penicllin allergic
What are the antibiotics given for Bite Wounds?
Debride and leave in sterile dressing rather than close
Tetanus risk
Swab the wound
Dog Bites: Pasturella, strep, staph and Neisseria
Cat Bites: Pasturella, strep, Neisseria
Human bites:
Give co-amoxiclav 5 days OR doxycycline + metronidazole if penicllin allergic
How are open fractures treated?
BOAST
- IV antibiotics within 3 hours of injury and continued until debridement
1. 2g co-amoxiclav or 1.5 cefuroxime
1. 2 g co-amoxiclav 1.5mg/kg from debirdement and 72 hours after/closure of wound - Assess neurovascular status (vascular damage and compartment syndrome require immediate surgery)
- Splint limb
What types of joint surgeries are there?
Replacement: give function back
Fusion: prevent further pain where replacements are not usually sucessful e.g. ankle
Removal: e.g. toe joints or trapezium in OA
CAUSES OF A SWOLLEN JOINT
CHRIST
Crystal arthropathies Haemophilia Rheumatoid arthritis (and other inflammatory) Infection Synovial pathology Trauma
