Lecture 7- Ortho Flashcards
first line for bones?
Xray
when to use CT
- bone detail: extent and severity of fracture
- fracture fragment evaluation
when to use MRI?
- occult (hidden) fracture evaluation
- tumor eval
- soft tissue injuries (ligaments, meniscus, rotator cuff)
Describe use of bone scans
- involves IV injection of radioactive tracer that accumulates in bone that is undergoing rapid turnover/growth
- imaging of choice for detecting skeletal metastases
describe use of US in ortho
newer applications- include evaluating superficial structures (tendons), guiding injections, screening long bone fractures
Xray Views
comparison views
- esp use in kids
- compare R & L respectively
how to systematically read xray
- adequacy
- alignment
- bones (sometimes nutrient vessels look like fractures)
- cartilage (is there space where cartilage would be? can’t actually see cartilage)
- soft tissue
how to view xray
- look at each bone (smooth contours, lucencies/opacities)
- look at each joint
- look at soft tissue
what color usually are fracture lines?
lucent (black)
Shoulder
tips for shoulder view
- don’t forget to view clavicle (separate image)
- need to know view to read image
Shoulder
Grashey vs AP
- Grashey: glenohumeral joint, humeral tuberous
- AP: better for acromialclavicular joint, some parts of humerus
Humeral View
when/what views to order? what should be visible for good image?
- only order if concern for shaft fracture or tumor
- joint above & below
- always do IR & ER unless fracture or dislocation
Elbow Imaging
what is soft tissue issue
- pos fat pad sign (sail sign)
- dark area displacing the fat pad indicating blood/injury
Elbow Imaging
how to get proper AP view
lay arm as flat as possible
Elbow Imaging
purpose of the radiocapitellar line?
- helps us know if it is dislocated
Forearm Imaging
components
- just changing from pronation to supination does not give 2 proper views of radius/ulna
- make sure entire unit moves together
- bones should mostly overlap on lat view
- must include wrist + elbow
Wrist Imaging
components
- does not have to include fingers
- does not have to include radius/ulna shaft
- too much radius/ulna are sometimes signs of bad images
- scaphoid view ordered here
Hand Imaging
components
- “ok” sign for lat view
- finger tips should be visible
- oblique view to look at metacarpals
Hip Imaging
components
- AP, frog leg, pelvis most common
- cross table lateral possible not common
- MAKE SURE TO LOOK AT PUBIC RAMI
- bilat hip is different from pelvis
Femur Imaging
components
- AP should include knee and hip to be adequate
- difficult to accomplish lateral because of lead in groin and overlap of pelvis structures
- ok if not perfect, caution w reshooting
Knee Imaging
components
- several views possible, based on problem
- look at fibula & tibial tubercule
- should be WB unless fracture & pt can’t stand
Knee Imaging
when to use tunnel imaging?
ligament damage
Tib/Fib Imaging
Components
- often anlged on film because leg is too long
- must include knee/ankle joints
- only performed for fractures and tumors
Knee Imaging
which views should be wt bearing
Ap, Lat, oblique
Ankle Imaging
components
- AP + Lat: arthritis
- AP + Lat + Mortise: injuries
- mortise “straightens” things out
- don’t ignore post ankle
Fracture Terminology
Simple Closed fracure
2 fracture fragments, skin intact
may take 7-10d to be visible on xray
Fracture Terminology
compound (open) fracture
2 fracture fragments, skin is penetrated
Fracture Terminology
comminuted (complex) fracture
2+ bone fragments
Fracture Terminology
transverse
fracure like — across bone
Fracture Terminology
Spiral fracture
- “spiral” break in bone (curling)
- caused by rotational forces
- common in children (femur), aging females (humerus)
Fracture Terminology
oblique fracture
diagonal fracture ( / )
Fracture Terminology
angulation
- to describe direction of fracture
- dorsal, radial, ulnar, valgus, varus, lateral, medial
Fracture Terminology
displacement
- describe the DISTAL fragment when looking as displacement (proximal part of bone is the “anchor”)
- can be full displacement or side to side movement of the fragments
Fracture Terminology
Distraction vs Overriding
- distraction: fragments have been pulled apart
- overriding: overlap of fragments/shortening
Fracture Terminology
impaction
fragments have been driven together
Fracture Terminology
stress fracture
- opaque on imaging NOT lucent
- summation of microfractures caused by unusal or excess stress (athletes)
- tibia is common site of stress fx in all ages
Fracture Terminology
Pathologic Fractures
- fracture through bone abnormality (benign or malignant leading to bone weakness)
- minimal or no trauma
Fracture Terminology
Avulsion fracture
- fracture of bony fragment that is produced by the pull of a ligamentous or tendinous attachment
Fracture Terminology
describe avulsion fracture of the knee
- Segond fracture
- highly associated with ACL tear, get an MRI
Pediatric Fracture Terminology
- physis
- diaphysis
- physis: grwoth plate, bone formation here, weakest part of bone
- diaphysis: shaft
Pediatric Fracture Terminology
Salter-Harris Fracture types for physis fractures
SALTER
Type 1: straight across physis
Type 2: above physis (meta)
Type 3: below physis (epi)
Type 4: through everything
Type 5: crushed
Pediatric Fracture Terminology
greenstick fracture
- incomplete fractures where the bone “bends like a twig” and the cortex cracks
Pediatric Fracture Terminology
torus fractures
- buckle fracture, type of incomplete
- creates a “bump” without an obvious fracture line
- very common- seen w/ falls on outstretched hands (FOOSH)
Fracture Healing Terminology
callus formation
fracture line is no longer clean + lucent
bony bridging of fracture line
Fracture Healing Terminology
nonunion
- causes: infection, inadequate immbolization, inadequate blood supply, inadequate nutrition
- non healing fracture
Fracture Healing Terminology
rate of fracture healing depends on?
age, type of fracture, nutritional/hormonal status, adequacy of tx
Fracture Healing Terminology
malunion
healed in bad positioning
Common Fractures
Scaphoid- overview
- 5% have complications (nonunion, osteoarthritis, avascular necrosis)
- surgically repair, refer to ortho if you see it
Common Fractures
colles fracture overview
- fracture of the distal radius with dorsal angulation of the distal fragment
- +/- ulnar styloid fracture
- FOOSH (hyperextension injury)
Common Fractures
Smith Fracture
- fracture of distal radius with palmar angulation of the distal fragment
- fall on back of flexed hand
Common Fractures
Radial head fracture
- easily missed- look for posterior fat pad sign
- most common elbow fracture in adults
- caused by fall on outstretched arm or direct blow to elbow
Common Fractures
boxer fracture
- fracture of head of 5th metacarpal
- usually result of punching solid object
- usually closed
- prescribe abx; if they punched someone in mouth give abx
Common Fractures
hip fracture risk factors
- old people more common due to brittle bones
- risk factors: osteoporosis, age, high energy trauma, pathologies that weaken bone
Common Fractures
Hip fracture- what part of bone most common
femoral neck or intertrochanteric region
Common Fractures
which view is best initial view to look for hip fractures? which is best for occult fractures?
- initial: AP pelvis
- occult: MRI
Common Fractures
hip fx lines may be difficult to see in who?
pts w/ osteoporosis
Joint Injury Terminology
define subluxation
incomplete loss of contact between articular surfacces
Joint Injury Terminology
define dislocation
complete loss of contact between articular surfaces
Joint Injury Terminology
which is most common site of dislocation?
shoulder
Joint Injury Terminology
differentiate posterior and anterior shoulder dislocation
- posterior: humeral head appears superior to glenoid cavity on AP film
- anterior: humeral head appears inferior to glenoid cavity on AP film
Non-Traumatic Skeletal Pathology
describe osteoarthritis
- most common joint disease
- clinically: pain, deformity, limited ROM
- most common cause of disability after age 65 yrs
Non-Traumatic Skeletal Pathology
radiographic signs of OA
- asymmetric joint space narrowing
- sclerotic bone changes (more dense)
- degenerative cysts (more lucent)
- osteophyte formation (bone spurs)
Non-Traumatic Skeletal Pathology
what joints are most typically affected by OA?
- DIP
- 1st metacarpal-carpal
- hips
- knees
- spine
Non-Traumatic Skeletal Pathology
answer OA question on slide 85
ok
Non-Traumatic Skeletal Pathology
describe rheumatoid arthritis
- inflammatory arthritis
- joints become painful, swollen, deformed w/ morning stiffness
- most commonly affects MCP, carpal, PIP joints (DIP involvement unusual)
Non-Traumatic Skeletal Pathology
radiographic signs of rheumatoid arthritis
- symmetric joint space narrowing
- periarticular osteopenia or osteoporosis
- osseous erosions
- MCP subluxation (which causes ulnar deviation clinically)
Non-Traumatic Skeletal Pathology
go label OA vs RA slides on pt
ok
Non-Traumatic Skeletal Pathology
bone tumors
- sharply marginated lesions are usually benign (benign = risk of breaking)
- fuzzy borders, outside bone margin usually indicates malignancy (cancerous = risk of dying)
Non-Traumatic Skeletal Pathology
most common cause of bone tumors?
metastatic lesions are more common than primary cancerous lesions
Non-Traumatic Skeletal Pathology
describe osteomyelitis
- focal destruction of bone due to infection
- happens via hematogenous spread, contagious spread, or direct inoculation
Non-Traumatic Skeletal Pathology
which radiographic modalities are best for dx osteomyelitis
- bone scan or MRI
if you can see it on x-ray it has been going on for a while
Spine/Head Imaging
role of xray? ct? mri?
- xray: initial screening for some conditions or in low-resource areas
- ct: initial screen ing for pts w/ C-spine trauma (esp if need concurrent brain eval), good for localizing fracture fragments!
- mri: in trauma to look for spinal cord, disc, or ligament injruy; study of choice for most diseases of spine
Spine/Head Imaging
describe c-spine trauma imaging
- 50% of c-spine trauma is due to MVA
- if imaging is indicated use CT
- rural places may use x ray but stuff gets missed
Spine/Head Imaging
when do not do radiography at all?
NEXUS low risk pt- meets ALL conditions:
* no posterior midline cervical tenderness
* normal level of alertness
* no evidence intoxication
* no focal neurologic deficits
* no painful distracting injuries (e.x if broken toe also do c spine)
Spine/Head Imaging
ABCS of viewing miages
- adequacy (all vertebrae seen, no rotation)
- Alignment (four smooth curves in correct direction)
- Bones (fractures of vertebral bodies, lateral masses, laminae, spnious processes)
- Cartilage (intervertebral disc spaces, interspinous process distances)
- Soft tissues (preverterbral soft tissues, esp C1-C3)
Spine/Head Imaging
what are the four curves of alignment? go to slide & label image too!
- anterior verterbral body line
- posterior vertebral body line
- spinolaminar line
- tips of spinous processes
Spine/Head Imaging
what would absent curves mean?
whiplash, muscle spasms
Spine/Head Imaging
describe components of distractive-flexion injuries
- posterior ligament tear
- occurs due to hyperflexion sprain; bilateral “perched” facets
- bilat facet dislocation = bilat interfacetal dislocation
- unilateral facet dislocation (w/ rotational component) causes nerve root injury
- big spaces, slanted forward
Spine/Head Imaging
describe compressive flexion c spine injury
- anterior fracture of vertebral body
- wedge compression fracture
- flexion teardrop (causes anterior cord syndrome due to retrolisthesis of vertebral body into ant portion of spinal canal)
Spine/Head Imaging
describe distractive extension injury
- anterior ligament tear
- causes central cord syndrome due to compression of the spinal cord w/in spinal canal
- hyperextension spain, hyperextension teardrop
Spine/Head Imaging
describe compressive-extension injury
- posterior fracture
- unilat or bilat fractures of lamina, lateral masses (pillars), or spinous processes
- pedicolaminar fractures result in separation of lateral mass from vertrab (hyperextension fracture dislocation)
Spine/Head Imaging
describe axial compression
vertebral body burst fracture
Spine/Head Imaging
describe lateral bending injuries
- uncinate process fracture
- unilat vertebral body or posterior element fracture
Spine/Head Imaging
describe clay shoveler’s fracture
isolated spinous process fracture of C7 (or C6, T1)
Spine/Head Imaging
describe spinous process by shoulder muscle injuries
- pull by shoulder muscles (Scapular rhomboid muscle) or direct impact to spinous process
Spine/Head Imaging
describe:
* anterior column
* middle column
* posterior column
- anterior: ant longit ligaments, anterior annulus, anterior 2/3 vertebral body
- middle: posterior 1/3 of verterbral body, post annulus, posterior longit lig
- posteior: posterior elements (pedicles, facets, lamina, spinous process), posterior ligaments
Spine/Head Imaging
how to tell if spinous fracture is stable?
if only one column is disrupted then the injury is stable. If multiple columns are disrupted, then the injury is not stable
Spine/Head Imaging
what is a burst fracture?
unstable- involves anterior and middle columns
Spine/Head Imaging
when could a two column injury be managed conservatively?
with a middle coluumn injury and an intact posterior ligmament complex (PLC)- get MRI to evaluate
Spine/Head Imaging
steps to viewing thoracic spine
- go through the same steps as c spine but also look at ribs/costovertebral joints
- look at vertebral bodies (origin of compression fractures)
- check for kyphosis
Spine/Head Imaging
steps/tips for viewing lumbar spine
- go through same steps as C-spine
- also look at Si joints, vertebral bodies (compression fractures)
- check “scotty dogs” for spondylolysis and spondylolistheses
- check for severity of lordosis
Spine/Head Imaging
describe scotty dog sign
- seen on oblique view
Spine/Head Imaging
differentiate:
* jefferson fracture
* hangman fracture
* odontoid process fracture
- jefferson: axial loading injury, fracture of C1
- hangman: extension injury; fracutre of posterior elements of C2
- odontoid: flexion/extension injury, more common in elderly
Spine/Head Imaging
which cervical vertebrae are most commonly fractured?
- C5-C7
- C1/C2
Spine Imaging
imaging for bain pain
- acute back pain top 5 PCP complaint
- 90% will resolve w/out imaging or intervention
- problem: most adults 40+ will have degeneratvie lumbar spine changes on conventional radiograph + degenerative disc changes on MRI which is normal finding for age
- should wait for sx to persist for 4-6 wks prior to imaging unless red flags
Spine Imaging
red flags that indicate need for imaging
7
- severe, progressive neurologic deficit
- minor trauma in OA pts
- major trauma in all other pts
- prolonged use of corticosteroids
- hx of cancer/unintentional wt loss
- recent bact infection/fever
- immunesuppression
Spine Imaging
compression fractures
- may occur w/ minimal stress in pt w/ osteoporosis
- most frequently involves middle lower thoracics & upper lumbar
- major cause of morbidity in geriatric population
Head/Spine Imaging
when to use CT for head?
- complicated sinusitis (can see fluid, mucosal thickening, sinus wall erosion)
- evaluating facial/skull fractures
- acute head/neck trauma
- detecting hemorrhage
Spine Imaging
when to use MRI for head/spine?
- modailty of choice for evaluating most other spinal cord & intracranial abnormalities
- better tissue constrast than CT
