MSK radiology Flashcards
What are the 4 patterns of arthritis?
Degenerative, inflammatory, depositional, infection
What are some characteristic features of degenerative arthritis?
- loss of articular cartilage in the joint space in an irregular fashion
- subchondral sclerosis
- osteophyte at joint margins
- subchondral cysts
Where does OA typically affect?
the hip, the knee, the first metacarpal joint of the thumb, DIP
What are some hallmarks of inflammatory arthritis?
1.inflammation of synovium or pannus formation
2.focal osteoporosis
3.Erosions at margins of joint and then articular cartilage 4.loss
5.subluxation and deformity
Occurs at the wrist, MCP, PIP, MTP, IP in feet
What might you find on X-ray in a person who has had many episodes of gout?
periarticular erosions at the margins of joints, or calcific deposits in soft tissues (tophi)
When do X-rays changes become apparent in septic arthritis?
2-3 weeks after onset of clinical symptoms
What are benign features of a bone lesion?
well defined border, sclerotic border, linear periosteal patten, stable over time, absent soft tissue mass
What some malignant features of a bone lesion?
ill defined border, cortical destruction, sunburst/codman triangle periosteum. Presence of soft tissue mass. Increase in size over time
what are the rule of 2s for MSK fractures?
2 views, 2 joints, 2 times
what sort of things are you looking for on imaging for RA?
erosions, periarticular osteopenia, synovitis (seen on MRI). loss of joint space
19 year old woman in MVA. Midline rear passenger wearing seat belt. What injuries is she susceptible of?
(proximal) Bowel injury- bowel ischaemia can result
Liver injury, pancreas injury
Fracture of the spine
what do you think if you saw a widened mediastinum on CXR for a MVA trauma patient?
aortic rupture
what is the look on a lateral X-ray of a colles fracture?
dinner fork deformity. Distal radial fracture
what sort of fractures do we commonly with anterior shoulder dislocations?
Hill-Sachs lesions are a posterolateral humeral head compression fracture, typically secondary to recurrent anterior shoulder dislocations, as the humeral head comes to rest against the anteroinferior part of the glenoid.
what are some radiological characteristics of septic arthritis?
Demineralisation and rapid articular cartilage loss is diagnostic of untreated septic arthritis
what do we worry about for subcapitalar neck of femur fractures?
avascular necrosis due to disruption of the retinacular arteries
how can we classify neck of femur fractures?
subcapitular or intratrochanteric
what are some features of pagets disease on X-ray?
Paget’s disease of the bone
- lytic lesions and sclerotic lesions
- disorganised trabeculae
- expanded bone
- bowed legs
tell me about stress fractures and X-rays?
stress fracture due to repetitive abnormal stresses on normal bones
- usually see the healing response on X-ray (e.g. formation of new callus)
what imaging do we use to look at marrow oedema?
STIR- T2 weighted MRI with fat suppression
what sorts of fracture classification do we have for ankle fractures?
Webers classification:
A- fracture is below the syndesmosis
B- at the level of the syndesmosis
C- syndesmosis is disrupted.
4 features of OA on X-ray?
osteophytes
subchondral sclerosis
subchondral cysts
reduced joint space
signs of RA on Xray?
periarticular erosions usually PIP, soft tissue swelling, loss of joint space, deformity
D’s for Charcott’s foot?
Debris
destruction
dislocation
deformity
what can cause diffuse osteopenia
renal osteodystrophy
osteomalacia
myeloma
Paget’s disease of the bone characteristics on XRAY?
bowing deformity, trabeculae loss, hyper expansion (osseous expansion)
Complications of paget’s disease of the bone
osteosarcoma cranial neuropathies pathological fracture malignant fibrosarcoma high output cardiac failure
What other bones can paget’s affect?
tibia, skull, pelvis
What sort of tumour is often found in the finger?
enchondroma (lytic lesion of the bone)
what are the cancers that metastasise to the bone?
- breast
- prostate
- lung
- thyroid
what is the mercedes benz sign?
sign on Lateral shoulder X-ray to look for anterior or posterior shoulder dislocation
what is the drumstick sign?
indicates internal rotation of the humeral head of the shoulder joint. Seen on a AP projection
features of psoriatic arthritis on X-ray?
The hallmark of PsA is the combination of erosive change with bone proliferation, in a predominantly distal distribution (i.e. interphalangeal more than MCP joints). The disease most commonly involves the hands, followed by feet. It can also affect sacroiliac joints and spine.
