RADIOLOGY Flashcards
INDICATIONS FOR XRAYS IN ORTHO
⦁ hx of blunt trauma
⦁ deformity of bone or joint following injury
⦁ hx of pain, swelling, or loss of motion of a joint, have a sense of instability
⦁ infection
⦁ foreign body
⦁ night pain
MRI
MRI = provides good contrast between the different soft tissues of body; easy to evaluate fluid within muscle or tendon to tell if torn or not. especially useful in imaging brain, muscles, heart, and cancer
BRAIN, MUSCLES, HEART, CANCER
- very rarely get MRI to evaluate bone; more for soft tissues (ligament, tendon, muscle injury)
- most bones evaluated with xray or CT
indications for MRI
⦁ evaluate soft tissue injury as opposed to bony injury. Ex: ligament, tendon, muscle injury
⦁ better evaluate soft tissue mass
⦁ r/o fluid collection in the body
⦁ define abnormalities within bone seen on xray
⦁ r/o stress fracture or infection
⦁ evaluate spinal injury
MRI TO EVALUATE SOFT TISSUE INJURIES
- Knee: ACL / MCL / PCL / LCL / meniscus, loose body
- Shoulder: rotator cuff, biceps tendon, labrum
- Elbow: UCL/RCL, extensor/flexor tendons for epicondylitis, biceps tendon rupture, loose body
- Wrist: Extensor carpi ulnaris injury, TFCC tear
- Ankle & Foot anterior tibial tendon injury, peroneal, tibial tendon, achilles tendon partial tear
- Hip - Labral tear
Labral tear = one of the biggest reason to get MRI (inject contrast dye to evaluate labrum)
ASPIRATED FLUID FROM KNEE AND WHAT IT MEANS
⦁ bright red blood aspirated = ACL
⦁ dark red blood aspirated = venous blood = patellar dislocation
⦁ if blood / fat = tibial fracture
MRI FOR SOFT TISSUE MASSES
⦁ lipoma
⦁ hematoma
⦁ osteosarcoma
⦁ ganglion cyst
wouldn’t really get an MRI for ganglion cyst location on dorsal ganglion; but if ganglion cyst located elsewhere, may not be as sure…
MRI FOR FLUID COLLECTION IN BODY
⦁ Effusion of a joint - shoulder, hip
⦁ no need to MRI, olecrenon bursitis, patellar bursitis
⦁ infection of fluid collection within soft tissue compartments
⦁ baker’s cyst in the knee
MRI TO FURTHER EVALUATE BONE ABNORMALITIES FOUND ON XRAY
⦁ Stress fracture: tibia, metatarsals, tibial plateau, femoral neck ⦁ lytic or blastic lesions seen on xray ⦁ bone contusion ⦁ r/o occult fracture, scaphoid fracture ⦁ AVN ⦁ osteomyelitis
Also used for spine pathology
seen better on MRI compared to xray
stress fractures (ex: tibia)
scaphoid fractures
AVN
risk factors for AVN
alcohol use
chronic steroid use
MRI FOR SPINAL PATHOLOGY
⦁ Herniated disc ⦁ bulged disc ⦁ spinal stenosis ⦁ compression fracture (acute vs chronic) ⦁ neoplasm ⦁ pars defect
indications for CT
⦁ Cervical injury - can’t see on xray well due to overlapping shadows. can better rule out cervical fracture after trauma with CT
⦁ To better define comminuted fractures (acetabular fractures, calcaenous fractures, articular fractures)
⦁ evaluating joints for preop eval for surgery
⦁ CT Myelogram of spin = for ppl who can’t undergo MRI (pacemark/other metal objects). Myelogram = CT with dye injected into dura
Indications for CT Myelogram
patients who have had previous spinal surgery, or patients who don’t qualify for MRI (pacemaker/other metal objects) - -inject dye into dura
indications for CT over xray
- cervical injury - ex: odontoid fracture
- tibial plateau fracture
- talus fracture
- calcaneal fracture
- bony bankart
BONE SCAN
- can be full body or localized to a body part
- will show bone turn over and osteoblastic acttivity, but will NOT show osteoclastic activity
- bone scans = best used for mets disease - such as prostate cancer
- not good for lytic lesions (clastic activity) - such as Multiply Myeloma
- other reasons for scans = stress fracture (MRI), infection (MRI), or occult (hidden) fractures
bone scans = not good for
multiply myeloma
lytic lesions
- clastic activity
tibial stress fracture
bone scan or MRI
one place bone scans are definitely used for =
tibial stress fracture
and mets
PLAIN XRAYS IN ORTHO - KNOW HOW TO DESCRIBE FRACTURE
⦁ Displacement ⦁ angulation ⦁ impaction ⦁ intra-articular ⦁ comminuted ⦁ spiral ⦁ greenstick ⦁ buckle ⦁ transverse vs oblique
- be wary of intra-articular fractures
- get AT LEAST 2 xray views 90 degrees to each other
- re-xray in about 1 week
view of xray good for evaluating glenohumeral joint
axillary view
also true AP
shoulder Y view = good for dislocations / fractures
xray of hand
get AP, oblique, and lateral
most commonly fractured bone in children & adolescents
CLAVICLE
M > F
80% are in the middle 1/3 of clavicle (mid shaft)
15% are distal 1/3
5% are proximal 1/3 (uncommon) - more worrisome
Y view is an xray view of the
shoulder
mortis is an xray view of the
ankle
zanca view
30-45 degree cephalic tilt
for clavicle fracture, along with AP view
helps evaluate displacement and comminution
humerus fracture = worry about radial nerve, which would cause
radial palsy
humerus fractures
2nd most common upper extremity fracture, after radius
usually occurs in adults > 65
- in adults > 65 = 3rd most common fracture, after radius and hip
women > men
what views for humeral head fracture
AP
lateral
Y view
TREATMENT OF HUMERAL HEAD FRACTURES =
Treat comorbidities that may increase the risk of non-union: Osteoporosis, alcoholism, tobacco use, mental illness, steroid use, rheum dz
what views for humeral shaft fracture
AP & LATERAL
get shoulder & elbow in views
- humeral shaft fractures = worried about radial nerve (most common) - could also damage median or ulnar nerve –> results in radial palsy.
distal radius fracture = worried about which nerve
median
scaphoid fracture = worry about
AVN - radial artery
MRI for scaphoid fracture
scapholunate dissociation
gap between scaphoid and lunate bones = indicative of scaphoid lunate dissociation - tear
damage to scapholunate interosseous ligament
SCAPHOID FRACTURES
scaphoid fracture = worry about necrosis (avn - due to radial artery compression)
⦁ get PA, lateral, and scaphoid view (AP with 30 degrees supination & ulnar deviation)
⦁ look for widening of scapholunate distance
⦁ high risk of nonunion
⦁ xray may be normal initially; check for snuffbox tenderness
⦁ repeat xray in 10-14 days
⦁ bone scan = more cost effective than MRI; can show uptake in 72 hours
⦁ MRI = same sensitivity as bone scan, but better specificity. expensive
⦁ CT - helps to see fracture line & displacement….
snuffbox tenderness
scaphoid fracture (navicular)
terry Thomas sign
scapholunate dissociation
colles fracture vs smith fracture
both are distal radius fracture
colles = hand = dorsal / posterior angulation (opposite direction of where the fracture is bending)
smith = hand = ventral / anterior angulation
Bennet’s Fracture vs Rolando fracture
intraarticular fracture through base of the 1st MCP
Rolando’s fracture = comminuted bennet’s fracture - T or Y shaped
Boxer’s fracture
fracture at neck of 5th metacarpal
(maybe 4th too)
(from punching with a clenched fist)
- always check for bite wounds
TUFT FRACTURE
fracture of the cancellous bone at the distal tip of the finger
pistol grip deformity
obese kid
Maisonneuve fracture
ankle injury results in concomitant fibular fracture
⦁ see widening of the ankle mortise = strongly suggests a tear of the distal tibiofibular syndesmosis
fibular fracture = need to look at
ankle! - mortise view
- proximal shaft of 5th metatarsal (similar to boxer’s fracture of the hand)
jones fracture
