Orthopaedics Flashcards
what is Paget’s disease of the bone?
it’s a condition characteristed by disorganised bone resorption and formation
how can Paget’s disease present?
often asymptomatic bone pain heat over affected area patient >40yo raised ALP hearing loss
what is the treatment for Paget’s disease?
normally no treatment. if severe, one off IV bisphosphonate injection (zolendronic acid)
what is the difference between rickets and osteomalacia?
rickets is Vit D deficiency in growing child, osteomalacia is Vit D deficiency in adults
why does vitamin D deficiency cause rickets and osteomalacia?
because it impairs the absorption of calcium, therefore preventing proper bone mineralisation
how does rickets present?
bone deformities
growth impairment
muscle weakness and pain
how does osteomalacia present?
bone pain
fractures
muscle weakness and pain
what is osteogenesis imperfecta?
a genetic condition that affects Type 1 collagen
name some symptoms of osteogenesis imperfecta
frequent fractures short stature growth impairment blue sclera dentigenesis imperfecta hyperlaxity scoliosis hearing loss
how is osteogenesis imperfecta managed?
- bisphosphonates to prevent fractures
- surgery for fractures
- social adaptations
- genetic counselling
what is the definition of osteoporosis?
thin bones with increased risk of low trauma fractures
what is the purpose of a DXA scan?
it measures bone density in the desired area
given the pathogenesis of Paget’s disease, what can be a complication of the condition?
the disordered osteoblast/osteoclast activity could give rise to osteosarcoma
what is the difference between osteopenia and osteoporosis?
osteoporosis is a more severe stage of bone loss than osteopenia
what is the first line treatment for osteoporosis?
bisphosphonates
name a few side effects of bisphosphonates
oesophagitis
uveitis
which patient groups are most likely to develop osteoporosis?
men over 50
women post menopause
patients on long-term steroids
name a few treatment options for patients with osteoporosis
bisphosphonates
HRT (women)
denosumab (anti-RANKL)
teriparatide
name a few side effects of HRT for osteoporosis
increased risk of breast ca if prolonged use
increased risk of blood clots/MI/stroke
what causes gout?
build up of uric acid in joint spaces
what is the management of an acute attack of gout?
NSAIDS
colchicine
steroids
lifestyle advice
should asymptomatic hyperuricaemia be treated?
no
should you attempt to treat hyperuricaemia before, during or after an acute attack of gout
wait until after the acute attack has settled
what medications can be used to treat hyperuricaemia?
allopurinol
febuxostat
probenecit
canakinumab
name a few causes of uric acid underexcretion
renal impairment hypertension hypothyroidism certain drugs (eg alcohol, diuretics) dehydration
name a few causes of uric acid overproduction
malignancy severe psoriasis drugs (eg alcohol) metabolic diseases HGPRT deficiency
what is pseudogout?
a type of arthritis, similar to gout, but which normally presents in knee joints in elderly women and is caused by a build up of different crystals to gout
what is polymyalgia rheumatica?
sudden severe stiffness of shoulder and/or pelvic girdle
what is the treatment for pseudogout?
NSAIDS
steroids
what investigation can be done to confirm gout when diagnosis is not clear?
synovial fluid analysis for crystals
what condition is polymyalgia rheumatica often associated with?
giant cell arteritis
name a few signs/symptoms of polymyalgia rheumatica
high ESR
old age (>70)
anaemia
malaise
what is the treatment for polymyalgia rheumatica?
prednisolone
what are the four stages of bone fracture healing?
- inflammation
- soft callus
- hard callus
- bone remodelling
how does inflammation promote the start of bone healing after a fracture?
inflammation encourages blood supply to increase to the fractured area
how does muscle attempt to stabilise the bone after a fracture?
it contracts to try keeping the bone together
what does formation of a soft callus depend on in bone fracture repair?
formation of a soft callus depends on the blood and oxygen supply to fractured area
why is it better to use someone’s own bone when using a bone graft to repair a fracture, rather than using bone from the bone bank?
own bone is made of collagen reinforced with crystals, which is stronger than hydroxy-apatite crystals alone which make up bone bank bone
how does a soft callus become a hard callus during bone fracture repair?
fibroblasts that make up the soft callus turn into osteocytes in response to mechanical strain
which ossification centres are responsible for 1. circumferential bone growth; 2. longitudinal bone growth?
- primary (endochondral) ossification centre
2. secondary (epiphyseal) ossification centre
what process occurs during the formation of hard callus in bone fracture repair?
cartilage is replaced by woven bone
what process occurs during bone remodelling in bone fracture repair?
woven bone is replaced by lamellar bone
what external stimulus is crucial for bone fracture repair?
mechanical strain
name a few factors which can cause delayed union in bone fracture repair
high energy injury infection instability distraction smoking drugs (steroids, warfarin, NSAIDS, immunosuppressants, ciprofloxacin)
what is the pathology behind acute osteomyelitis?
infection reaches bone through blood supply at metaphysis.
inflammation results in increased pressure.
pus is released into medulla/periosteum.
pus in joint causes bone destruction and reformation.
outcome is resolution or chronic osteomyelitis
what is the most common organism to cause acute osteomyelitis?
staph aureus
if osteomyelitis occurs as a result of standing on a nail, what is the most likely organism?
pseudomonas
how does acute osteomyelitis present in infants?
- irritability
- failure to thrive
- may be fine or very unwell
- swollen tender joint
where does acute osteomyelitis commonly present in infants?
knee joint
how does acute osteomyelitis present in children/adolescents?
- severe pain
- no weight-bearing
- painful tender joint
- reduced range of movement
- swinging fever
why does osteomyelitis cause a swinging fever?
due to the presence of pus
what investigations can be done to confirm a diagnosis of acute osteomyelitis?
blood cultures (x3) FBC (esp neutrophil count) ESR CRP U&E joint aspiration X-ray bone scan ultrasound (especially in children) MRI
how is acute osteomyelitis treated?
fluid and pain management
rest/splintage
antibiotics
surgery
what is the term for the bone destruction/necrosis process in osteomyelitis?
sequestrum
what is the term for new bone formation in osteomyelitis?
involucrum
name a few examples of when surgery may be indicated in acute osteomyelitis
aspiration of pus for diagnostic purposes
abscess drainage/lavage
debridement of dead tissue from infected area
infected joint replacement
name a few complications that can occur as a result of acute osteomyelitis
abnormal bone growth chronic osteomyelitis metastatic infection pathological fractures septic arthritis
in which part of a long bone is acute osteomyelitis likely to start, and why?
commonly originates in the metaphysis, because it’s the most vascular area of the bone
name a few ways an infection can spread to cause osteomyelitis
hematogenous spread (eg from skin abrasions, tonsilitis) local spread (eg fracture, prosthetic)
which bones are more likely to develop osteoarthritis?
long bones
bones with intra-articular metaphysis (eg hip, radius)
what is the pathology behind chronic osteomyelitis?
chronic inflammation, possibly caused by retention of dead tissue inside the involucrum of new bone
how is chronic osteomyelitis managed?
long-term antibiotics
surgery for debridement/reconstruction
name a few likely organisms to be involved in chronic osteomyelitis
- staph aureus
- strep pyogenes
- e. coli
which bones are more likely to be affected by osteomyelitis in children and adults respectively?
children - limbs
adults - spine, hips
what is the pathology of septic arthritis?
an infection of the joint space
what is the commonest cause of septic arthritis in adults?
infection of joint replacement
name a few likely organisms to cause septic arthritis
- staph aureus
- strep pyogenes
- e. coli
- haemophilus influenzae
what investigations are done to diagnose septic arthritis?
FBC (WBC) ESR/CRP blood cultures joint aspirate testing ultrasound x-ray/MRI
how is septic arthritis treated?
pain/fluid management
long term antibiotics
joint lavage/drainage
joint replacement/reconstruction
what is the classification of bone/joint involvement in tuberculosis?
vertebral (most common)
intra-articular
extra-articular
what is the pathology of tuberculosis in the bone?
- initial site of infection (lung, GIT)
- secondary spread of infection
what investigations are done to diagnose bone tuberculosis?
Mantoux test sputum/urine swab FBC CRP/ESR x-ray MRI
what is the management of bone tuberculosis?
Rest/splintage
Anti-TB medication (isoniazin, ethambutol, pirazynamide, rifampicin)
What is the most common site of bone tuberculosis?
Spine
How can bone tuberculosis present?
Back pain
Kyphosis
Osteopaenia around infection site
how can bone tuberculosis present?
back pain
Kyphosis
osteopaenia around infection site
systemic symptoms of TB
in the knee, which meniscus is more likely to tear and why?
medial is more likely to tear as it is more fixed and less flexible
what is the treatment of a meniscal tear?
rest
NSAIDS
physiotherapy
how does a meniscal tear present?
swelling
locking
clicking
pain
what investigations are done to diagnose a meniscal tear?
x-ray
MRI
how does an ACL tear normally occur?
due to a twist in the knee on landing
why do meniscal tears not tend to heal?
because they have very limited blood supply
what is the unhappy triad of the knee?
ACL rupture
medial meniscus rupture
MCL rupture
name a few immediate symptoms of an ACL tear
pop/crack sound deep pain haemarthrosis swelling instability
which ligament in the knee only really tends to rupture as a result of an ACL tear?
anterolateral ligament
what are treatment options for ACL tears?
non-surgical: quadriceps muscle strenghtening
surgical: ACL reconstruction
what is the most common ligament to tear in the knee?
medial collateral ligament
how does an MCL tear normally occur?
contact causing severe valgus stress on the knee
how does an MCL normally present?
pop/crack sound
swelling
severe pain
bruising on medial side of knee
how is MCL normally managed?
conservatively with rest, NSAIDS, physiotherapy and sometimes a brace
what is osteochondrosis dissecans?
a condition which causes parts of articular cartilage/subchondral bone to fragment resulting in inflammation in the joint
which insertion of the ligament is normally ruptured during a MCL tear?
the femoral insertion of the MCL
what is osteochondrosis dissecans?
a condition which causes parts of articular cartilage and/or subchondral bone to fragment and cause inflammation in the joint
how is osteochondrosis dissecans normally managed?
arthroscopy to fixate loose fragment
what are common causes of osteochondrosis dissecans in children and adults?
children/adolescents - activity related
adults - secondary to avascular necrosis