MSK: Part 8 Flashcards
Define fractures
- Soft tissue injury in which there is a break in the continuity of surface of substructure of the bone
Where do high energy injuries take place
Pelvic or femur fracture
What is the bone shaft in children called
Diaphysis
What is the peri-articular part of the bone called (ends of long bones)
Metaphysics
What is physics
Growth plate that has not fused
Blood supply of the epiphysis
Endoosteal and periosteal blood supply
Why is healing of bone better in children than adults
Children have an EXCELLENT PERIOSTEAL BLOOD SUPPLY so their rate of healing is MUCH HIGHER and is thus SIMPLE
More cancellous bone present in children which is softer - simple repair needed
Why are ligament damages in children very rare
They are extremely strong
Why do ligament injuries in children cause fractures
So strong - bone to bone
If they tear, they take the bone with it
Common fracture site in neonates
Humerus and clavicle due to fracture from birth
Common fracture site in infants
Radius
Common fracture site in children
Fibula, radius and femur
Common fracture site in adolescent
Tibia
What is an oblique fracture
Diagonal tear
What is a transverse fracture
Horizontal
What is a linear fracture
Vertical
What is a spiral fracture
Diagonal around the bone perimeter
What is a comminuted fracture
Section between bone is fragmented and separates the bone
What usually causes comminuted fracture
High energy impact
What causes a spiral fracture
Twisting injury
Where is an oblique fracture found
Ankle due to axial load injury
What age group is effected by greenstick fracture
SPECIFIC to children
What is a greenstick fracture
Unicortical fracture in which the bone bends and breaks due to thick periosteum
How easy is it to treat a greenstick fracture
EASILY because bone is not completely broken down
What is the salter-Harris fracture classification
Classification for fractures involving the physics (growth plate) - higher the number the more damage and worse prognosis
What are the most common parts of the bone that get fractures in children
Epiphysis
Metaphysis
Major complication of Salter-Harris fracture classification
GROWTH ARREST
How are fractures managed
- Reduce fracture -> restore length, alignment and rotation -> immobilise (to allow healing) -> rehabilitate
How do most kids fractures heal
Non-operatively due to extremely quick healing as a result of their thick periosteum with excellent blood supply
What deformity will be remodelled if there is more than 2 years growth left in a bone
Angular deformities
What deformity will not be remodelled if there is more than 2 years growth left in a bone
Rotational deformity
How do we tell if a child has angular or rotational deformity
Regular X-rays to ensure no rotational/angular movement
Treatment for paediatric fractures
- Internal operational fixation
2. External fixation
What is Internal operational fixation
- Plate, screws, intramedullary nails or K-wire
Complication of internal operational fixation
If nails or K-wire INVADE the physics (growth plate) then there will be growth arrest
When are external fixations done
Lots of soft tissue swellings and damage so don’t want to open skin to reduce risk of infection and bad healing
Ex-fix or Lizard flame
Complication of an open fracture
Infection
Complication of fractures in general
Neuromuscular compromise
Malunion - bone heals with DEFORMITY
Non-union - Failure of bone to heal
Compartment syndrome
What is compartment syndrome
- Painful condition in which the pressure within the fascia builds to dangerous levels usually caused by bleeding within the fascia
Where is compartment syndrome common
Tibia
What causes compartment syndrome
Cast (too tight) or post-op bleeding of fascia
How is compartment syndrome treated
Fasciotomy where fascia is removed
How do radiographs work
X-ray beam is directed through the body part under investigation and then into a plate
Various tissues absorb different amounts of X-ray beams
X-rays reach plate and are converted to light by phosphorescent effect
Light is then digitally recorded
The more X-ray radiation that reaches the detector, the darker the image becomes
What colour is bone on X-ray
White
What colour is soft tissue on x-ray
Light grey
What colour is fat on x ray
Dark grey
Cons of X-ray (non safety related)
Fractures take time to appear on X-ray
Early arthritis and early infection do not show
When requesting a radiograph what do we need to ask for to get a full picture of the injury
TWO VIEWS of the body
How does a CT work
Radiation source is fired through patient and then what passes is detected
Multiple slices of the body seen
AXIAL
What people is CT dangerous for
Foetus and children are sensitive to radiation
Pregnancies unless condition is life-threatening
How many days of background radiation is CT equivalent to
3 days
When is a CT useful
Assess ACUTE injuries when X-rays are inadequate
Give greater information about known fractures
Assess fracture healing and complications such as infection
Look for loose bone fragments in joints
Gives excellent detail of bone and joint pathology
When is an MRI preferred to CT in fractures
Soft tissue injuries
How does a Ultrasound scan work
HIGH FREQUENCY SOUND WAVES pass through soft tissues and reflected at tissue interfaces - good res
Reflected waves or echoes are measured by probe
Difference between normal ultrasounds and MSK ultrasounds
Uses highest frequency, linear array probes for better res of small soft tissue structures
Why re ultrasounds safe
NO Radiation or magnetic field
What sound wave should not be used in foetal scanning
Power doppler
When is USS used
Tendon and ligament soft tissue injuries and anatomy
assessment for joints and synovial abnormalities, effusions and cortical erosions
Guide biopsies and fluid drainage
How does an MRI function
- Patient is placed in a powerful magnetic field
- 30,000 x stronger than the earth’s magnetic field
- Scanner is narrow and often induces claustrophobia
How does an MRI work
- T1 energy: released from spinning proton to surrounding lattice
- T2 energy relaxation: Released from spinning proton to adjacent spinning protons
Pathology of MRI
- Abnormal tissues contain more water than normal tissues
diseases appear DARKER on T1 and brighter on T2
Why are MRIs safe
No harmful effects from magnetic fields
When is MRI contraindicated
Patients with electronic implants and metallic heart valves, neurosurgical clips, metallic foreign objects in the eye
Consequence of metallic foreign objects in the eye if MRI is used
Transient tissue warming and visual disturbances
Why should MRI be avoided in pregnancy
uncertain foetal safety
Why is MRI used to assess bone fractures
Soft tissue pathology around bones and joints
Information on characteristics of tissue and pathology
Useful early in disease when plain radiographs may be normal
Con of MRI
Early diseases can’t be seen
When is Aldendronate given
Osteoporosis
Hypercalcaemia of malignancy
Myeloma and breast cancer bone metastasis as it reduces need for radiotherapy or surgery
Paget’s disease to reduce bone turnover and pain
How do bisphosphonates function
Inhibit osteoclasts and promoting apoptosis
Adverse effects of bisphosphonates
- Oesophagitis (orally)
- Hypophosphataemia
- Jaw osteonecrosis
When should bisphosphonates be avoided
- Severe renal impairment
- Hypocalcaemia
- Upper GI disorders
What compounds contraindicate bisphosphates
Absorption reduced by calcium products (antacids and iron salts)
When is calcium and vit D given
- Osteoporosis
- CKD to stop secondary hyperparathyroidism and renal osteodystrophy
- Calcium used in severe hyperkalaemia in arrhythmias
- Symptomatic hypocalcaemia
- Rickets and osteomalacia (VIT D)
What controls calcium homeostasis
- Parathyroid hormone and Vit D which increases serum calcium levels and bone mineralisation
- Calcitonin which reduces serum calcium levels
Restoring positive calcium balance reduces the rate of bone loss and prevents fractures
Adverse effects of calcium and vit D oral medications
- Dyspepsia and constipation
- DO NOT USE in hypercalcaemia
- Calicum reduces absorption of iron, bisphosphonates and tetracycline antidepressants
Example of Xanthine oxidase inhibitors
ALLOPURINOL
Is allopurinol a chemotherapy drug
Yes - stops hyperuricaemia and tumour lysis syndrome
How does allopurinol effect the plasma uric acid concentration
Lowers it
Contraindications for xanthine oxidase inhibitor
- SKIN RASH
- not with ACUTE GOUT ATTACKS - worsens these
- recurrent skin rash already on the drug
- IF patient is on azathioprine
- Amoxicillin, ACEI or thiazides increase hypersensitivity risk
Why is xanthine oxidase contraindicated with azathioprine
Requires xanthine oxidase for metabolism so allopurinol may increase their activity
name an anti-gout agent
Colchicine
Mechanism of colchicine
Inhibits neutrophil motility and activity which leads to a net anti-inflammatory effect which is useful in acute attacks
Contraindications for colchicine
- GI disturbances
- fatigue due to anaemia
- Renal impairment
- Peripheral neuropathy due to peripheral nerve damage
- Toxicity enhanced when using statins
How does methotrexate function
Inhibits dihydrofolate educates which converts dietary folic acid to FH4 (tetrahydrofolate) which is required for DNA and protein synthesis
What is FH4 needed for
Lack prevents cellular respiration
Anti-inflammatory and immunosuppressive effects mediated by IL-6 and TNF-alpha
Contraindications of methotrexate
- Sore mouth, GI upset, bone marrow suppression
- Hepatic cirrhosis and pulmonary fibrosis
- Severe renal impairment and abnormal liver function
What is Dupytren’s contracture
- Where fingers become permanently bent in a flexed position
What is hypothenar hammer syndrome
Occlusion of the ulnar artery and superficial palmar arch
What is Cozen’s test
TEST FOR LATERAL EPICONDYLITIS:
Rested wrist extension causing pain in lateral epicondyle - extensor carpi radialis causes this
What is repetitive strain disorder’s differential diagnosis
Tenosynovitis and epicondylitis
