msk formative Flashcards
What is a pseudo tumour
An inflammatory granuloma produced in response to metal wear particles in the context of a joint replacement which may be locally invasive but cannot metastasise
What is a neurotmesis
Complete transaction of a nerve requiring surgical repair for any change of recovery of function
What is axonotmesis
Nerve injury sustained due to compression or stretch or from a higher degree of forces, with death of the long nerve cell axons distal to the point of injury die
What is neurapraxia
A temporary conduction defect from compression or stretch and will resolve over time with full recovery
What is Wallerian degeneration
Long nerve cell axons dying
T/F prognosis is worse as Salter-Harris classification increases
T
Vessel at risk in shoulder dislocation
Auxiliary artery
Vessel at risk in knee dislocation
Popliteal artery
How is chronic osteomyelitis managed ?
Antibiotics and surgery
An example of a fracture that has a high rate of non-union due to poor retrograde blood supply
Waist of scaphoid fractures
What is CRPS (chronic regional pain syndrome)
Needs urgent referral to orthopaedics
It is a heightened chronic pain response after an injury
What is the radiocapitallar joint responsible for ?
Supination / pronation along with the proximal and distal radioulnar joints
What muscle powers elbow extension
Deltoid via olecranon process
Which muscles are responsible fro elbow flexion
Brachialis and biceps
The humero-ulnar joint is is responsible for what action
Flexion and extension
What are the 4 muscles that make up the rotator cuff
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
What structure is impinged in hip impingement t
Acetabular labrum
What structure is impinged in shoulder impingement
Rotator cuff tendon
T/F risk of recurrent shoulder dislocation following a traumatic shoulder dislocations increases with age after first time dislocation
F - it decreases
Adhesive capsulitis affects which movement
External rotation
What makes up a + Froment’s test
1st dorsal interosseous and adductor pollicis weakness = + Froments
(Innervated by ulnar nerve)
What are the conditions that increase likelihood of developing Carpal tunnel
RA
Pregnancy
Diabetes
CKD
Hypothyroidism
Colles fracture
Which sex more likely Carpal tunnel
8:1 W
What degree of fixed flexion deformity is required at MCPJs for a patient to fail the Hurston Table Top test
> 30 degrees
Is the periosteum in kids much thicker than adults ?
YES - proportionally so
What percentage of women develop brachial plexus injury in childbirth
0.2%
What is mallet finger
An avulsion of the extensor tendon from its insertion into the terminal phalanx and is caused by forced flexion of the extended DIPJ - often from a ball at sport
Present with a drooped DIPJ of the affected finger and inability to extend
Are thoracic-lumbar wedge type fracture stable ?
Yes - they do not need surgical intervention
*lightbulb sign on x-ray
Posterior shoulder dislocation
What is needed to clear C-spine in A&E
-no pain on gentle active neck movement
-no significant distracting injury
-GCS 15 with no alcohol
-no neurological symptoms in lower or upper limbs
-no midline tenderness
How are intra-capsular fractures often treated
With hemiarthroplasty or THR
Splintage required for femoral shaft fractures
Thomas splint
Example of a tendon which is commonly surgically managed conservatively
Long head of biceps
Which tendon ruptures need surgical repair
Quadriceps tendon
Patellar tendon
What is a transverse fracture
Pure bending force is applied to bone
The cortex on one side fails in compression and the cortex on the other side fails in tension
What is an oblique fracture
Bone is exposed to shearing force ie falling
There is risk of shortening and angulation with these fractures - they are inherently unstable
What is a spiral fractire
Torsional forces acting on the bone
These ones are the MOST UNSTABLE but can also angulate
What is Wolf’s law
Refers to fracture having the potential to remodel over time
They change shape with areas of stress
When does primary bone healing occur
Minimal fracture (<1mm) and the bone bridges the gap with the new bone from osteoblasts
Ie hairline fractures and when fractures are fixed with compression screws and plates
What is secondary bone healing
Majority of fractures - the gap at the fracture site needs to be filled temporarily
Involves an inflammatory response with recruitment of pluropotential stem cells
Imaging modality of choice for suspected DDH
Ultrasound
What is femoral neck anteversion
Mild intoeing and apparent knock knees
However the degree of apparent intoeing is not of a magnitude which would warrant surgical intervention
What is internal tibial torsion
Mild intoeing
Alignment of the knees seems normal but the tibial tubercle appears internally rotated
What is forefoot adduction
Can cause apparent intoeing , the rotational and coronal alignment of the hips, knees and ankles appear normal
Surgery indicated after year 7-8 of life - before this should resolve itself
What is talipes equinovarus
Ankle equinas (plantarflexion) supination of the forefoot and varus alignment of the forefoot
Who gets acute osteomyelitis more
Kids more than adults
Which nerve is particularly at risk of injury in humeral shaft fractures
Radial nerve
Are flat feet present at birth
At birth , all feet are flat and the arch develops as we begin to walk and the muscles of gait develop
In some people the flat foot will persist into adulthood without any functional problem
Nail changes of psoriatic arthritis
Onycholysis
Pitting
A malignant tumour of endothelial cells in the marrow
Most cases occur between 10-20 years, may be associated with fever , raised inflammatory markers and a warm swelling and may be misdiagnosed as osteomyelitis
Ewings sarcoma
Most common primary bone tumour
Osteosarcoma
A malignant primary bone tumour that occurs in abnormal bone
Most commonly in adolescents and young adults
Fibrosarcome
*chalky material discharging from joint
Erosive arthritis
(Crystalarthropathy)
Which artery is most at risk in a paediatric supracondylar fractire
Brachial artery
The thickest hyaline cartilage in the body is found on the articular surface of which bone ?
Patellar
Where is the patellar tendon
Attaches patella to tibial tuberosity
Do ACL ruptures need surgery all the time
No not all will need surgery
Define ‘knee locking’
Describes the lack of full extension possible in the situation where a meniscus has sustained a bucket handle tear and torn the inner portion of the meniscus has displace into the notch and front of the knee
A spongy block of usually 10-15 degrees to active and passive knee extension due to a displaced bucket handle meniscal tear
What will a valgus malalignment of knee in the lateral compartment predispose the patient to
Early osteoarthritis
What is the Ortolani test
Palpable clunk as the examiner abducts the flexed hip
What is Barlow test
In joint abnormal femoral head to posteriorly dislocated from the acetabulum with a palpable clunk as the examiner pushes the flexed hip posteriorly
What is mallet finger
Avulsion of the extensor tendon form the distal phalanx resulting in inability to actively extend the DIPJ
Name
A = greater trochanter
B = lesser trochanter
C = pubic symphysis
D = superior pubic rami
E = lesser tuberosity
*hyperextension at PIPJ with flexion at DIPJ
Describes what deformity
Swan neck deformity
What is the Danis - Weber classification
A simple method for classifying fractures of lateral ankle fractures - based on radiographic material
Split into type A, B and C
What does a type A Danis Weber describe
Fracture of lateral malleolus
Treatment = usually stable and can be managed with plaster cast or orthosis
Type B Danis - Weber classification
Fracture at level of the tibial plafond
Treatment = implies a degree of damage to the syndesmosis itself - not visible on x-ray
Usually unstable - may need surgery
Type C - Danis - Weber
Describes fracture proximal to level of tibial plafold with syndesmotic injury
Treatment = ORIF (unstable)
What are the Ottawa ankle rules
Determine need for radiograph in acute ankle injuries - avoids unnecessary imaging
When would an ankle x-ray be required ? (Ottawa)
If there is any pain in the malleolar zone and:
(Any one of the following)
- bone tenderness along the distal 6cm of the posterior edge of tibia or tip of medial malleolus
- bone tenderness along the distal 6cm of the posterior edge of the fibula or tip of the lateral malleolus
- an inability to bear weight both immediately and in the emergency department for four steps
When would a foot x-ray be required? (Ottawa)
There is any pain in the midfoot zone and :
(Any one of the following)
- bone tenderness at the base of the 5th metatarsal
- inability to bear weigh both immediately and in the E.D
Dislocation to shoulder at humerus can cause damage to which nerve
Axillary
Fracture at mid-shaft of humerus can cause damage to which nerve
Radial
Get a loss of function down the posterior forearm and loss of sensation down arm
Distal humerus fracture in young people can cause damage to which vessel
Brachial artery
Axillary nerve damage can cause shoulder weakness - why ?
Innervates the deltoid
A medial condyle fracture can damage which nerve
Ulnar nerve
Galezzi fracture
Distal humerus
GRUESOME (g - galezzi r - radial fracture - u - ulnar dislocation)
Monteggia fracture
Proximal humerus
MURDER (m-monteggia , u - ulnar fractures, r-radial dislocation)
*garden spade deformity
Smithsa
*dinner fork deformity
Colles
What is the blood supply to the scaphoid
Dorsal carpal branch of radial
Which scaphoid fractures are managed conservatively
Distal scaphoid and the body
*proximal fracture needs surgery as artery is at risk
*telescoping thumb
Bennett’s
What type of fracture would end up in a high energy trauma
Comminuted - so much energy bone ‘explodes’ from within
Which Garden classification types need internal fixation
I and II
Treatment for fractures above the inter-trochanteric line
Replacement
Tx of fractures below the inter-trochanteric line
Dynamic hip screw
Treatment of subtrochanteric fractures
IM nails
Damage to neck of femur could lead to what nerve damage ?
Superior gluteal nerve - relevant as this nerve —> innervates gluteus medius —> abducts and keeps hip level
Mxm of ACL vs PCL
ACL = usually surgery
PCL = will heal by itself (conservative)
*bucket handle meniscal tear treatment
Surgery with arthroscopy
What quad muscle flexes the hip ?
Rector femoris
Main causative organisms for discitis
Staph aureus
Gonorrhea
*onion-skinning
Ewing’s sarcoma
What are the 3 main malignant bone tumours
Ewings sarcoma
Osteosarcoma
Chondromsarcoma
*sunburst appearance on x-ray / Sharpey’s fibres
Osteosarcoma
*isolated raised ALP (phosphate and calcium are normal) ?
Paget’s
Why can you get a vitamin D deficiency
- Poor diet
- Lack of sun
- Kidney not working
What makes something pANCA or cANCA ?
Ratio of serum proteinase 3 and myeloperoxidase
Ie. More MPO = pANCA , more PR3 = cANCA
GPA vs MPA ?
GPA = cANCA
MPA = pANCA
*DVT/ clots + nephrotic picture or CKD ?
Deficiency of anti-thrombin III
