Orthopedics Flashcards
where do bone metastases arise from?
THE PUBLIK
Thyroid
H?
E oesophageal
Prostate (!) Urinary bladder Breast (!) Lung (!) Intestines Kidneys
(!) indicated most common
features of a benign bone lesion
a geographic border (well demarcated)
narrow zone of transition
single layered periosteal reaction
e.g. non-ossifying fibroma (common in children and adolescents), osteochondroma (owergrowth near growth plate, common in ages 10-30) and endochondroma (ages 10-30)
features of malignant bone lesions
a poorly demarcated border
wide zone of transition
multi-layered periosteal reaction (types –> codman triangle, onion-peel, sunburst)
e.g. osteomyelitis, Ewing’s sarcoma (5-15 y/o), osteosarcoma (10-30 y/o - second commonest primary bone tumour) and multiple myeloma (>40 y/o - the commonest primary bone tumour - spine, skull, ribs and pelvis)
NOF O/E
abducted, externally rotated and shortened
NOF location and risk of AVN
displaced intracapsular # - high risk of AVN (total hip replacement/ hemi-arthroplasty)
undisplaced intracapsular # - moderate risk of AVN (pin)
intratrochanteric or subtrochanteric extracapsular # - low risk of AVN (dynamic hip screw)
mortality risk after a #NOF
10% in 1 month
33% in 1 year
what is Cauda Equina syndrome
compression of the nerves below the level of L1
can be due to malignancy, a slipped disc, vertebral #, trauma, infection
symptoms - bilateral sciatica pain, numbness around anus, painless urinary retention leading to overflow incontinence and bowel retention
must check sensation, muscle tone, muscle weakness and the rectal cough reflex
–> MRI to confirm and surgery within 48hrs
Salter-Harris classification of epiphyseal injuries
SALT CRUSH
1 - Straight across (sheer injury of growth plate)
2 - Above (above GP with metaphysis #)
3 - Lower (# of epiphysis
4 - Through (# through epiphyseal GP and metaphysis)
5 - CRUSH (crush injury to GP)
median nerve
sensory: lateral palm, thumb and lateral 2.5 fingers
motor: LOAF hand muscles
movement thumb abduction against resistance
injury: carpal tunnel
palsy: thenar eminence wasting, hand of benediction (can’t make a fist), weak thumb abduction (ape hand - can’t oppose)
tests: Tinel/Phalen +ve
ulnar nerve
sensory: medial hand and medial 1,5 fingers
motor: small muscle of the
movement: finger abduction against resistance
injury: elbow (Golfer’s elbow - medial)
palsy: hypothenar eminence and 1st web wasting, claw hand (can’t straighten), weak finger abduction
tests: +ve Froment’s sign
radial nerve
sensory: lateral dorsum of hand
motor: extensors - fingers, wrist and elbow
movement: wrist/ finger extension against resistance
injury: humeral shaft #
palsy: Saturday night palsy. wrist drop, weak inger and wrist extension
where in the finger does a Mallet finger deformity affect?
the DIP joint (bent forward)
can be due to an avulsion injury or due to the extensor tendon rupture
where in the finger does a Boutonniere deformity affect?
the PIP joint (will not straighten and the DIP is bent back)can be due to trauma or RA
causes of Carpal Tunnel syndrome?
MEDIAN TRAP
Myxoedema E - oedema premenstrual Diabetes Idiopathic Acromegaly Neoplasm
Trauma
RA
Amyloidosis
Pregnancy
Compartment Syndrome
> 20mmHg pressure is abnormal but >40mmHg is abnormal
6Ps Pain (excessive for injury present) Paraesthesia Paresis (muscle weakness) Poikilothermia (impaired temperature, very cold) Pallor Pulseless
–> emergency fasciotomy
what classification is used to classify open fractures?
the Gustilo and Anderson classification
how would you manage an open fracture?
ABCDE Ax, analgesia and tetanus booster control bleeding - fluid/ blood replacement assess soft tissue and NV status cover wound with sterile saline gauze splint # and reassess NV status surgical debridement and stabilisation
Weber’s classification of distal fibular #s
A - below syndesmosis (usually stable - reduce and cast)
B - at level of syndesmosis (variable stability - may require open reduction and internal fixation ORIF)
C - above level of syndesmosis (unstable - ORIF required)
Osgood Schlatter’s disease
inflammation of the area just below the knee where the patellar tendon attaches to the tibia
most often occurs during growth spurts (10-14)
conservative treatment - ice, analgesics and NSAIDs
Perthes Disease
rare childhood (4-10) condition of the hip causing AVN ~15% of cases are bilateral
stages:
initial/ necrosis: limb and change of gait (several months)
fragmentation: woven bone replaces dead bone (1-2 years)
re-ossification: stronger bone develops
healed:
symptoms - limp/ change of gait, pain in hip/groin, muscle spasm, if untreated can lead to early onset arthritis
treatment –> observation and limited activity, NSAIDSs, physio, casting and bracing
septic arthritis
50% of cases are in the knee, the most common organism is Staph Aureus
bacterial seeding via bacteraemia, direct inoculation or contiguous spread
causes irreversible cartilage destruction
symptoms - pain, fever, erythema, effusion, warm and tender, inability to weight bear and unable to do PROM
extremity is FABER (flexed, abducted and externally rotated)
–> IV Ax. .operative irrigation and drainage
tendonopathies
disease of the tendon, pain on palpation and on movement
spinal stenosis
narrowing of the spinal canal or neural foramina producing root ischaemia and neurogenic claudication
DDx - cauda equina syndrome
osteoarthris
degenerative joint disorder, progressive loss of hyaline cartilage and new bone formation at the joint surface
risk factors: age, female, obesity and developmental dysplasia of the hip
–> analgesics, intracapsular injections and total hip replacement
main signs on X-ray (LOSS): loss of joint space, osteophytes, subchondral cysts and subchondral sclerosis
osteoporosis risk factors
Age + SHATTERED
Steroids Hyper-para/thyroidism Alcohol and cigarettes Thin (BMI <22) Testosterone low Early menopause Renal/liver failure Erosive/ inflammatory bone disease (RA, myeloma) DM or dietary Ca low/ malabsorption
often presents with pathological fractures
–> bisphosphonates
what organism is present after an animal bite?
Pasturella multocida
how do you work out risk of shoulder re-dislocation?
100-age = %age chance that the shoulder will re-dislocate
how much must a humeral fracture be angulated by before it is classified as ‘angulated’?
> 45 degrees
which ligament is the most likely to damage in an ankle injury?
the anterior talo-fibula ligament
vaRus
knees apart, lower leg Reaching towards each other
vaLgus
knees together, lower legs Leaving each other
which tendon is at risk of rupture during a Colles’ fracture?
the extensor pollicis longus
prostate bone met characteristic
sclerotic
kidney bone met characteristic
lytic
tetanus
incubation period of 10 days
blocks NT release from spinal inhibitory neurones
causes muscle stiffness and spasm, dysphagia, breathing problems and suffocation
complication of #s
early (compartment syndrome, NV compromise)
middle (DVT/PE, infection)
late (malunion, AVN)
what sling should be used for a clavicle #
a broad arm sling
what sling should be used for a mid humeral #
a collar and cuff
joint fluid analysis
normal (clear, WCC <200, low neutrophils <25%)
non-inflammatory arthritis (clear/yellow, WCC <2000, low neutrophils <25%)
inflammatory arthritis (clear/cloudy yellow, WCC >2000, neutrophils <50%)
septic arthritis (opaque, WCC >50000, neutrophils >75%)
gout vs psuedogout on microscopy
gout = negatively birefringent needles pseudogout = positively birefringent needles
DEXA scan score interpretation
T score is the standard deviations against a average from a 20-something population
Z score is adjusted for the patient’s sex and age
t score -1.0 to -2.5 is osteopenia,
Paget’s disease of the bone
a disease of increased but uncontrolled bone turnover, - primarily a disorder of osteoclasts with excessive osteoclast reabsorption followed by increased osteoblastic activity.
possibly triggered by paramyxovirus
only 1 in 20 are symptomatic
predisposing factors include increased age, male, northern latitude and family history
features bone pain, untreated fractures, increased ALP,
Rx: bisphosphonates, oral risedronate or If zoledronate
complications: deafness (due to CN entrapment), bone sarcoma, #s, skull thickening, high-output cardiac failure)
osteomalacia and rickets
normal bony tissue but reduced mineral content - due to vitamin D deficiency
rickets (when growing - get knock-knees, bow legs and features of hypocalcaemia, x-ray: cupped ragged metaphysical surfaces), osteomalacia (bone pain, fractures, muscle tenderness and proximal myopathy, x-ray: translucent bands - looser’s zones/ pseudofractures)
Rx: calcium and vitamin D tablets
osteogenesis imperfecta
brittle bone disease - disorder of (type 1) collagen metabolism resulting in bone fragility and fractures - autosomal dominant
mildest and most common form is type1
presents in childhood, may be mistaken for non-accidental injury, get blue sclera and deafness secondary to otosclerosis
Rx: IM rods in long bones, bisphosphonates may increase cortical thickness
gangrene
death of tissue from poor vascular supply and is a sign of critical limb ischaemia - tissues are black and may slough
dry gangrene
necrosis in the absence of infection
a line demarcates the living and dead tissue
Rx: restoration of blood supply +/- amputation
wet gangrene
tissue death and infection (associated with discharge)
Rx: analgesia, broad-spectrum IV ABx, surgical debridement +/- amputation
gas gangrene
subset of necrotising myositis caused by spore forming clostridial species often clostridium perfringens
rapid onset of myonecrosis, muscle swelling, gas production, sepsis and severe pain
risk factors include DM, trauma, and malignancy
Rx: amputation, benzylpenicillin +/- clindamycin, hyperbaric O2 can improve survival and reduce the number of debridement needed
Back pain red flags
age <20 or >50 history of malignancy nocturnal pain history of trauma, steroids or HIV systemically unwell non-mechanical pain thoracic pain
spinal stenosis
usually gradual onset, unilateral or bilateral leg pain (may have back pain), numbness and weakness - worse on walking, relieved by sitting down
requires an MRI to confirm
ankylosing spondylitis
typically a younger male patient who presents with lower back pain and stiffness - usually worse in the morning and improves with activity
peripheral artery disease
claudication when walking, relieved by rest, absent or weak foot pulses and other signs of limb ischaemia
past history may include smoking and other vascular diseases/ risk factors
osteomyelitis
a bacterial infection of the bone - may be spread haematogenously, traumatically or from a soft tissue infection
commonest is staph aureus (haemophilus influenzae in children and salmonella in HbS)
Rx: flucloxacillin for 6 weeks
what is the unhappy triad/
lateral force to an extended knee
medical collateral ligament, anterior collateral ligament and medial meniscus damage
Ottawa ankle rules
only need to X-ray if pain in malleolar zone and:
- inability to weight bear for four steps
- tenderness over distal tibia
- bone tenderness over distal fibular
most likely to injure the anterior talo-fibular ligament
Charcot Joint
aka neuropathic joint
the arch of the foot collapses due to damage secondary to sensory loss
typically swollen, red and warm but less painful than expected
due to DM, tabes doralis, leprosy, syringomyelia, cauda equina lesion
adhesive capsulitis
aka frozen shoulder
painful on active and passive with reduced ROM, difficulty sleeping on affected side
pain with freezing > thawing > resolution (can take up to 2 years)
commonly the supraspinatus is torn
tennis vs golfer’s elbow
Tennis is played on the Lawn (lateral epicondylitis)
Golf is played in the Meadow (medial epicondylitis)
scoliosis vs kyphosis
scoliosis (lateral curvature)
kyphosis (exaggerated anterior curvature of thoracic spine)
both can cause restrictive lung disease (due to reduced expansion) and nerve/cord compression, and have psychological effects
common nerve damage that causes foot drop
common fibular nerve damage
developmental dysplasia of the hip
risks (7F's) fetal factors e.g. multiple pregnancy floppy (hypotonia) feet first (commoner in breech presentation) first born female family history freezing (commoner in winter born babies)
ASA classification for anaesthesia
ASA I = a normal healthy patient
ASA II = patient with mild systemic disease
ASA III = patient with severe systemic disease
ASA IV = patient with a severe systemic disease that is a constant threat to life
ASA V = moribund patient who is not expected to live without the operation
ASA VI = brain dead patient, operation is for organ harvesting
