MUSCULOSKELETAL SYSTEMRevision quiz

CONNECT THE DISEASE AND MORPHOLOGY

Acute mastitis

Periductal mastitis

Lymphocytic mastopathy

Fat necrosis

Keratinising squamous metaplasia of the nipple ducts

Single/multiple hard palpable masses; collagenised stroma surrounding atrophic ducts and lobules

Local infection single/multiple abscesses OR diffuse spreading infection that eventually involves entire breast; neutrophil infiltration, + necrosis

Painless palpable mass or skin thickening/retraction; haemorrhagic with liquefactive fat necrosis

WHICH LESION IS SHOWN IN THE PICTURE?

Ductal carcinoma in situ

Lobular carcinoma in situ

Invasive carcinoma

NAME THE ZONES OF THE EPIPHYSEAL PLATE

WHAT IS RANKL AND WHAT IS ITS FUNCTION?

Surface protein found on osteoblasts Binds to RANK on the surface of

osteoclast progenitors to stimulate differentiation into osteoclasts

WHAT IS OPG AND WHAT IS ITS FUNCTION? Osteoprotegerin Similar to RANK can bind to RANKL Ie. it prevents binding of RANKL/RANK

decreases stimulation of osteoclast differentiation

Produced by both osteoblasts and osteoclasts

WHAT IS THE MOA OF BISPHOSPHONATES? Inhibit recruitment and activation of

osteoclasts inhibits enzymes on the cell border

Promote osteoclast apoptosis it is absorbed by osteoclasts

Indirect: stimulate osteoblast activity

Eg. alendronate, risedronate

PTH Vitamin D3 Calcitonin

Inc Ca2+ absorption, inc phosphate absorption

Inc plasma Ca2+ and dec plasma phosphate

Backup during extreme hypercalcaemia

NAME AND DESCRIBE THE SALTER-HARRIS FRACTURES CLASSIFICATION

WHAT ARE THE STAGES OF FRACTURE HEALING?

Haematoma formation: fibrin mesh; provides framework for inflammation/fibroblasts

Inflammation Formation of a fibrocartilage callus Consolidation: woven bone lamellar

bone Remodelling: takes years; continuous

alternating resorption/formation

WHAT ARE THE OPTIONS FOR FIRST AID/EARLY MANAGEMENT OF A FRACTURE

DRABC + compression of bleeding + analgesia + prophylactic a/b

Closed reduction Traction Open reduction and internal fixation External fixation Casts splints Functional casts or braces

WHAT ARE SOME INDICATIONS OF A NON-ACCIDENTAL INJURY?

# in infant <12 months Avulsion # Metaphyseal # Bucket-handle # Multiple #s of varying ages Bilateral #s Site: posterior rib, scapular, metaphyseal,

distal clavicle, spinous processes, sternum Complex skull #

WHAT FEATURES AFFECT FRACTURES IN CHILDREN?

Thicker, strong periosteum with quicker callus formation

Inc Haversian canals incomplete fractures; more susceptible to fracturing due to compression

Inc cartilaginous bone not seen on x-ray, therefore must infer presence of injury

WHAT ARE SOME RISK FACTORS FOR CHILD ABUSE?

Parent: young age, single parent, unwanted pregnancy, poor parenting skills, early exposure to violence, substance abuse, inadequate prenatal care, physical/mental illness, relationship problems

Child: sex, prematurity, unwanted, disabled Family: size/density, poor SES, social isolation, high

stress levels, Hx of family abuse/domestic violence Community/society: non-existent/unenforced child

protection law, dec value of children (minority/disabled/gender), social inequalities, organised violence, high social acceptability of violence, media violence, cultural norms

NAME 3 BONE-FORMING TUMOURS Osteoma: benign, from

subperiosteal/endosteal surfaces; round-oval fixed tumour of dense sclerotic bone

Osteoid osteoma: benign, small painful well-circumscribed; teens/20s

Osteosarcoma: malignant mesenchymal tumour; long bone metaphysis; solitary intramedullar tumour with poor differentiation

MATCH DISEASE AND PATHOGENESIS Osteogenesis

imperfecta Achondroplasi

a Osteoporosis Osteitis

deformans Osteomalacia

Osteoclast dysfunction; osteolytic phase mixed phase osteosclerotic phase

Mutated FGF receptor 3 constitutive activation suppressed growth

Deficient synthesis of type I collagen

Defective matrix mineralisation, mostly due to lack of Vit D

Many factors (eg. menopause, aging) affect bone formation after peak bone mass is achieved

MATCH THE KNEE INJURY AND CLINICAL FEATURE

ACL tear PCL tear Medial collateral

ligament tear Meniscal tears Articular cartilage

injury Knee inflammatory

condition

Positive McMurray’s test

Positive Lachman’s test

Knee effusion Increased laxity with

valgus stress Positive posterior

draw test Knee effusion, pain,

fever

NAME THE LIKELY PRIMARY BONE TUMOURS

WHAT ARE THE THREE ROUTES OF INFECTION LEADING TO PYOGENIC OSTEOMYELITIS

Haematogenous (most common) Extension from contiguous site Direct implantation

WHAT ARE THE POTENTIAL COMPLICATIONS OF CHRONIC OSTEOMYELITIS?

Pathologic fracture Secondary amyloidosis Endocarditis Sepsis Sarcoma of the infected bone

FILL IN THE FOLLOWING TABLE

Benign bone tumour Malignant bone tumour

? Breath of cortex? Regular edge ? Demarcated edge? Sclerotic bone around edge? Extension into adjacent tissue? Periosteal reaction

Benign bone tumour Malignant bone tumour

? Breath of cortex No? Regular edge Yes? Demarcated edge Well demarcated? Sclerotic bone around edge

Yes

? Extension into adjacent tissue

No

? Periosteal reaction No

Benign bone tumour Malignant bone tumour

? Breath of cortex No Yes? Regular edge Yes No? Demarcated edge Well demarcated Poorly demarcated? Sclerotic bone around edge

Yes No

? Extension into adjacent tissue

No Yes

? Periosteal reaction No Yes

WHAT WOULD YOU SEE ON RADIOLOGY OF AN OSTEOSARCOMA?

Large, destructive, mixed lytic+blastic lesion with permeative margins

Sun-ray spicules Tumour frequently breaks through

cortex and lifts the periosteum reactive periosteal bone formation

A 49 year old female presents complaining her fingers have been stiff, swollen and sore.

What specifically would you ask on history?

She states that it seems to be in both in index fingers and is possibly beginning to affect her right thumb as well.

She states that the stiffness is worst in the morning and is relieved by using her hands.

She has difficulty writing and knitting. Also generally fatigued.

What is your DDx? What could you find on examination?

Symmetric joint involvement MCP > wrist > PIP > knee > MTP > shoulder

> ankle > cervical spine > hip > elbow > TMJ Affected joints: inflammation, swelling,

tenderness, warmth, dec ROM Rheumatoid nodules Ulnar deviation of fingers; swan neck or

Boutonniere deformities of the fingers, radial deviation at wrist

Effects on other joints Potentially extra-articular manifestations

FILL IN THE FOLLOWING TABLEAnkylosing spondylitis

Reactive arthritis

Psoriatic Colic arthritis

Male:female ratioPeripheral arthritisEnthesitisSkin lesionsSacroiliitisHLA-B27 prevalence

Ankylosing spondylitis

Reactive arthritis

Psoriatic Colic arthritis

Male:female ratio

2-3:1

Peripheral arthritis

Uncommon asymmetric lower limb oligoarthritis

Enthesitis CommonSkin lesions Nil (10%

have psoriasis)

Sacroiliitis Universal, symmetric

HLA-B27 prevalence

90%

Ankylosing spondylitis

Reactive arthritis

Psoriatic Colic arthritis

Male:female ratio

2-3:1 5:1 (sexually acquired); 1:1 (post-diarrhoeal)

Peripheral arthritis

Uncommon asymmetric lower limb oligoarthritis

Common asymmetric lower limb oligoarthritis

Enthesitis Common Very common

Skin lesions Nil (10% have psoriasis)

Circinate balinitis; keratoderma blennorrhagica

Sacroiliitis Universal, symmetric

40-60%, often asymmetric

HLA-B27 prevalence

90% 20-80%

Ankylosing spondylitis

Reactive arthritis

Psoriatic Colic arthritis

Male:female ratio

2-3:1 5:1 (sexually acquired); 1:1 (post-diarrhoeal)

1:1

Peripheral arthritis

Uncommon asymmetric lower limb oligoarthritis

Common asymmetric lower limb oligoarthritis

Common small and large joint, asymmetric

Enthesitis Common Very common

Common

Skin lesions Nil (10% have psoriasis)

Circinate balinitis; keratoderma blennorrhagica

Psoriasis

Sacroiliitis Universal, symmetric

40-60%, often asymmetric

~20%, often asymmetric

HLA-B27 prevalence

90% 20-80% 80% with sacroiliitis, 8% without

Ankylosing spondylitis

Reactive arthritis

Psoriatic Colic arthritis

Male:female ratio

2-3:1 5:1 (sexually acquired); 1:1 (post-diarrhoeal)

1:1 1:1

Peripheral arthritis

Uncommon asymmetric lower limb oligoarthritis

Common asymmetric lower limb oligoarthritis

Common small and large joint, asymmetric

Common, asymmetric lower limb oligoarthritis

Enthesitis Common Very common

Common Uncommon

Skin lesions Nil (10% have psoriasis)

Circinate balinitis; keratoderma blennorrhagica

Psoriasis Erythema nodosum, pyoderma gangrenosum

Sacroiliitis Universal, symmetric

40-60%, often asymmetric

~20%, often asymmetric

~20%, often asymmetric

HLA-B27 prevalence

90% 20-80% 80% with sacroiliitis, 8% without

80% with sacroiliitis, 8% without