Radiology Flashcards
What are reasons for ordering radiographic tests in ortho?
- hx of blunt trauma
- deformity of bone or jt following injury
- hx of pain, swelling, or loss of motion of a jt, sense of instability
- infection
- fb
- night pain
Use of MRI in general?
- provides good contrast b/t diff soft tissue of body, makes it especially useful in imaging brain, muscles, heart, cancers compared w/ other medical imaging techniques
Use of MRI in ortho?
- eval soft tissue injury as apposed to bony injury. Ex is ligament injury, tendon injury, muscle
- better eval of soft tissue mass
- R/O fluid collection in body
- define abnormalities w/in bone seen on x-ray
- r/o stress fracture or infection (osteomyelitis)
- eval spinal injury (gold standard for spine)
Specific structures we analyze w/ MRI?
- knee: ACL, MCL, PCL, LCL, meniscus, loose body
- shoulder: rotator cuff, biceps, labrum
- elbow: ulnar and radial ligaments, extensor and flexor tendon insertion for epicondylitis, biceps tendon rupture, loose body
- wrist: extensor carpi ulnaris injury, TFCC tear
- ankle and foot: anterior tibial tendon injury, peroneal, tibial tendon, achilles tendon partial tear
- hip: labral tear
Soft tissue masses seen on MRI?
- lipoma
- hematoma
- osteosarcoma
- ganglion cyst
Fluid collection that can be seen on MRI?
- effusion of jt, shoulder, hip
- no need for MRI olecranon bursitis, patellar bursitis
- infection fluid collection w/in soft tissue compartments
- baker’s cyst in knee
Bone abnorm you can see on MRI?
- stress fracture: tibia, metatarsals, tibial plateau, femoral neck
- lytic or blastic lesions seen on xray
- bone contusion
- r/o occult fracture, scaphoid
- avascular necrosis
- osteomyelitis
Spine pathology that you can dx on MRI?
- herniated disc
- bulged disc
- spinal stenosis
- compression fx, acute vs chronic
- neoplasm
- pars defect (acute vs chronic)
Reasons for ordering CT scan in ortho?
- cervical injury: due to mult overlapping shadows and images on xray, CT scan better r/o cervical fx after trauma
- reconstructing and better defining communited fx such as: acetbaular fx, calcaneous, articular**
- eval jts for preop eval for surgery
- better for bony surfaces
- CT myelogram of spine for individuals that can’t undergo MRI due to pacemaker or other metal objects. Myelogram is CT w/ radiographic dye injected into dura
What is a bone scan? Used for?
- nuclear medicine study: inject small amt of radioactive material and then scanned w/ gamma camera
- scan may be full body or localized: SPECT
- will show bone turn over and osteoblastic activity, but won’t show osteoclastic activity
- used for bone mets: prostate, less for lytic lesions (MM), also used for stress fracture, infection, occult fx
Ways to describe fx on xray? How many xrays should be done?
- displacement
- angulation (where is apex of fx?)
- avulsion
- impaction
- intra-articular
- comminuted
- spiral
- greenstick
- buckle
- transverse vs oblique
- number depends on location and injury: usually 2 views of 90 degrees to eachother, re-xr in a week
How many xray shoulder views should you get?
- AP: good for AC jt
- axillary: can see lesser tuberosity, glenohumeral jt
- Y: indication is if pt can’t give axillary view, trying to see dislocation
How many X-ray views of humerus are done?
- AP and lateral
Elbow xrays: how many views?
- AP (looking for avulsion fx) and lateral (have 90 degrees flexion)
What dictates if it is a true forearm xray?
- need full forearm in X-ray including wrist and elbow
- get AP and lateral
Wrist xrays?
- AP, lateral and oblique
Hand xray positions?
- AP, lateral, oblique
Lumbar spine xrays? what are we looking for?
- AP and lateral
- can get oblique: looking for pars fx (scotty dog)
- spinous processes
- kyphosis, lordosis
- arthritis
- SI jts: arthritis
- ankylosing spondylitis: see in SI jts first b/f bamboo spine
Pelvis xray?
want entire ring
- can see rami fx, want to see L5-S1
- get CT for pelvic fx (don’t want to miss anything)
What are we looking for on Hip AP?
- at acetabulum, femoral head (want it to be concave not convex - acetbaular femoral impingement)
- looking for crescent sign: AVN
RFs for AVN:
corticosteroids
previous fx, hip dislocation
ETOH
Xray views of knee?
AP, lateral, sunrise (can see patella)
- make sure wt bearing films are ordered (arthritis)
Xray views of ankle?
- mortis, lateral and AP
- AP: can’t see lateral jt like mortis (wan to make sure jt space is even - if not may have fx higher up)
xray views of foot?
- AP, lateral, oblique
- want to see tibial-talar jt, tarsals
Characteristics of clavicle fx? Dx?
- MC fx bone in kids and adolescents
- males more than females
- 80% middle third
- 15% distal
- 5% proximal
- dx:
H and P
XRs: AP - see both SC and AC jts, zanca view (30-45 degree cephalic tilt - helps to eval displacement and comminution)
MC dislocation of humerus? Why is this?
- anterior b/c of pec muscle
Characteristics of humeral head fxs? Dx?
- 2nd MC UE fx
- older than 65 3rd MC fx (1: radius, 2: hip)
- usually in adults older than 65
- females more than males
- surgical neck more common than anatomical neck
-dx:
XRs: AP, lateral, and scap Y
CT: if articular involvement of glenoid and humeral head
Tx of humeral head fxs?
tx comorbidities that may increase risk of nonunion:
- osteoporosis
- alcoholism
- tobacco use
- mental illness
- steroid use
- rheum diseases
Humeral shaft fx characteristics? Dx?
- usually occr from high impact injury (fall)
- worried about radial nerve
- dx:
XRs - AP and lateral, get shoulder and elbow in views
Presentation of anterior dislocation of humerus? Posterior?
- on xray: looks like humeral head is depressed
- posterior: almost looks normal, may look elevated
What muscle may pull on ulna if there is olecranon fx?
- triceps may pull up olecranon
Diff midforeram fx? Tx?
- radius and ulna: midshaft are unstable - refer to ortho
- isolated ulnar fx: if displaced less than 50% bone diameter and less than 10 degrees of angulation.
Short arm cast 2 wks then fxnl splint 2-6 wks
MC radial fx?
- distal radial
- FOOSH
- 1/6 of all fx tx
- xrays:
radial inclination, radial ht: 1 cm, volar tilt: normal is 10 degrees
Presentation of scaphoid fx?
- snuffbox tenderness
- worried about AVN of proximal end (retrograde blood flow)
Dx scaphoid fx?
- xrays of wrist: PA, lateral and scaphoid view (AP w/ 30 degrees of supination and ulnar deviation)
- look for widening of scapholunate distance (greater than 3 mm)
- high risk of nonunion: greatest at proximal pole
- xrays may be normal initially: if snuffbox tenderness and xrays negative be very suspicious - tx?
- repeat xray in 101-4 days
- bone scan: more cost effective than MRI, can show uptake in 72 hrs
- MRI: sensitivity same as bone scan, better specificity, but spendy
- CT: helps see fx line and displacement
Diff metacarpal fxs? Tx?
thumb:
- bennet’s: fx combined w/ subluxation or dislocation of metacarpal jt
- rolando fx: T or Y shaped fx involving jt space
- if extra articular fx: can consider closed reduction and thumb spica cast for 4-6 wks (less than 25 degrees angulation and rotation are acceptable limits for thumb)
- boxer’s fx: 5th metacarpal 1st time, if rotates while making a first - needs to be fixed
Tx of proximal phalanx fx that is transverse?
- splint
What heals faster: spiral or transverse fx?
- spiral: more bone to bone surface area
What fxs of fingers reqr further referral to ortho?
- anything that involves articulating surfaces
Tx of distal phalanx fx? When does this occur?
- usually from slamming finger in a door (tuft fx)
- tx if closed w/ minimal to no displacement-tuft or shaft:
stable, Al splint over tip of finger for 3-4 wks, leave PIP free
Pistol grip deformity is a sign of what?
- femoroacetabular impingement (some portion of the soft tissue around hip socket is getting pinched or compressed) - present w/ deep groin pain w/ activities that stress hip motion, may be clicking, catching
Tx for patellar transverse fx?
- straight leg knee immobilizer
Medial or lateral arthritis more common in knee?
- medial
What type of imaging should you get for tibial plateau fx?
- CT
MC etiology of isolated fibular shaft fx?
- direct trauma
What should you be concerned about if you see distal fibular fx on xray?
- ankle fx
- or vice versa: get ankle xray to look for widening of syndesmosis - means there is a fx more proximally
If you see medial malleolar fx what else will most likely be present?
- lateral fx
What is a Jones fx?
- proximal shaft of 5th metatarsal aka dancer’s fx
- type 1: nondisplaced or displaced (less than 2 mm)
tx: short leg cast w/ strict non-wt bearing for 6-8 wks (may take longer) - all types (I-III) consider surgical fixation
- run risk of nonunion (proximal area)
Tx for plantar fasciatis?
- stretching
How will osteosarcoma present?
- will be warm to the touch on palpation (high metabolism)
MC benign bone tumor?
- osteochondroma
Axillary view of XR looks at what?
- glenoid-humeral jt
What is a buckle fx? MC in what pop?
- MC in kids
- forearm fx
- compression fx on one side of bone to bend or buckle toward damaged side (stable fx)
Nursemaid’s elbow?
- child’s arm pulled = leads to subluxation of radial head, slips anteriorly out of annular ligament
- usually under 4
- present w/ extremity full pronated, flexed and held tightly to side
- AP and lateral films usually done
- tx: supinate and flex forearm and applly posteriorly directed pressure
What is SCFE?
- weakneing of epiphyseal plate of femur, resulting in displacement of femoral head, may be bilateral
- typicall presents: 10-16yo
- boys more than girls, obese, athletically inclined, african americans
- most cases are idiopathic but in younger child consider metabolic cause (hypothyroidism, or hypopituitarism)
- presentation: insidious hip, thigh, or knee pain assoc w/ painful limp
- imaging: lateral xrays will show post and medial displacement of epiphysis, best assessed when in frog leg or lateral hip view
- tx: pinning in situ is definitive
- should be on crutches and non-wt bearing
