Musculoskeletal 1 Flashcards
(51 cards)
1
Q
Commonly missed fractures
A
- Stress fracture
- Scaphoid, elbow, radial head, midfoot, tibial plateau, hip; supracondylar and torus fractures in kids
- Non-displaced and impacted fractures
- Non-displaced growth plate fractures
- Suspect fracture but negative xray? (Dx: Probable fx. Immobilize, Repeat xray in 2-3 weeks – look for callous, CT, MRI or bone scan next)
2
Q
Generalized decreased density = osteopenia
A
Diffuse lucency DDx: (think global process)
Metabolic/Endocrine
- Osteoporosis (late)
- Hyperparathyroidism
Malignancy
- Metastases
- Lung, renal, thyroid, breast CA
Regional
-Reflex Sympathetic Dystrophy Synd (RSDS)
3
Q
fractures: general concepts
A
- Radiographs provide confirmation (Hx (mechanism), PE, PMHx, age are key)
- Know anatomy, know views (Order what you need, shoot it once)
- Confirm all “suspected” fractures on >1 view
- Lots of overlap - account for and mentally subtract overlying structures - all views
4
Q
CPPD arthropathy
A
- chrondrocalcinosis
- psuedogout
5
Q
Myositis Ossificans
A
- Extra-skeletal ossification in soft tissue
- After blunt trauma
- Common in thigh
- Imaging: Xray, CT, MRI
6
Q
septic arthritis - non-pyogenic
A
- M. tuberculosis, fungus
- Risks: IVDU, DM, steroids, TB risks
- Indolent, slow
- Monoarticular
- Osteoporosis common
- Spine, knee common
- Red, hot, painful joint. Plain film changes are late, but order one first.
- May see subchondral erosions, periosteal reaction (above)
7
Q
Bones: decreased density (increased lucency)
A
Lucent (black) line: suspect fracture
Generalized lucency - Osteopenia
- Osteoporosis
- Endocrine/metabolic disorders, steroids
- Hyperparathyroidism, osteomalacia, rickets
- Multiple Myeloma (disseminated form)
Focal lucency
- Osteolytic metastases, bone cysts, some tumors
- Multiple Myeloma (solitary form)
- Osteomyelitis
8
Q
Open fracture (compound fx)
A
- High incidence of infection, osteomyelitis
- Crush injury: vascular complications, infection
- Irrigated and repaired in OR < 8 hrs
- Antibiotics, Tetanus
- Open tuft fx (exception to OR repair)
- Needs to be within 8 hrs!! EVERYONE GETS ABX AND TETANUS
- The only exception is tuft fx
9
Q
bone tumors
A
- Where? Joint violated? (tumors don’t cross joints)
- Margin? Sclerotic/thin, well-defined vs. irregular, ragged
- Shape? Longer than wide (w/in medullary) or wider than long (burst through cortex)?
- Characteristics? Geographic, permeative, “moth-eaten”, expansile, “soap bubbly”
- Bony reaction? Lytic, sclerotic
- Periosteal reaction? Codman’s, mixed, onion skin
- Tumors dont cross joints! they stay in the bones they originated in
10
Q
Bone scans - nuclear med
A
Indications:
- Occult Fractures
- Stress Fractures
- Bone Infection
- Avascular Necrosis
- Osteomyelitis
- Malignancy
11
Q
erosive arthritis: gout
A
- Calcium urate crystals
- Sharp, sclerotic “punched out” or “rat bite” erosions near affected joint
- Acute monoarticular arthritis grt toe: Podagra
- Severe = tophi, periarticular erosions, “punched-out” lesions
- Tophi = soft tissue
- She will not require us to tell apart gout from rheumatoid etc. ON A PICTURE → will need to know the characteristics of them
12
Q
CT scan: indications
A
- Complex, intra-articular fx’s (Characteristics, extent)
- Calcaneus, tibial plateau, talus, midfoot
- Spinal column
- Pre-op evaluation
- Occult fracture
- Associated injuries
- Tumors, infection
- Biopsy, interventional procedures
13
Q
erosive arthritis: psoriatic
A
- At DIP, spares PIP
- Subchondral erosions
- Terminal phalanges narrow “pencil in cup”
14
Q
Cartilage (joint space)
A
- Refers to joint spaces
- Normal appearance on xray views is key
- Widening: disruption, calcification, fluid
- Check if fracture extends into the joint (Intra-articular Fx)
- MRI best for ligamentous injury, disruption
- The joint space should be the same all the way around
- Intraarticular fracture means that the fracture extends into the joint space
- Decreased (Arthritis - most types, Impacted fx, dislocation)
- Increased (Fracture, dislocation, Hemarthrosis, Infection (pus))
- Chondrocalcinosis (Pseudogout, CPPD)
- Hemarthrosis – blood in the joint
15
Q
Intra articular fractures
A
- Fracture enters joint
- Important distinction
- Cartilage damage
- Ligamentous injury
- Joint is now at risk for degenerative arthritis
16
Q
Bones
A
- Check entire cortex, contour; size, shape of bones; check alignment
- Fractures (Lucent (black) line passes through cortex, Check entire cortical margin for disruption, Check for impaction (bulge, increased density), Acute Fx’s linear, jagged - edges not corticated, Fx’s should be visible on more than one view)
- Decreased density (lucency, osteopenia)?
- Increased density (opaque, sclerosis, impaction)? Generalized process or focal process?
- Break and fracture are the same thing!
- Contour is how the bone should look
- Torus fx is a buckle fracture → compression fracture
- FRACTURES ARE BLACK ON PLAIN FILM
- If you see something that looks white, its not a fracture
17
Q
Special views: plain xrays
A
- To highlight particular bones, angles, relationships, non-displaced fx’s, dislocation
- Confirm a questionable abnormality
- “Comparison views” - other side
- “Weight-bearing view” - AC joint, foot
- Perpendicular - axial plane (Patella, calcaneus, shoulder, wrist)
18
Q
hyperparathyroidism
A
- Generalized decreased bone density
- Overproduction of PTH (>PTH-> hypercalcemia (plasma), Increase in bone resorption, Stones, bones, abdominal groans)
- Osteoporosis
- Subperiosteal resorption of bone in fingers
- Subchondral resorption in distal clavicles
- “brown tumors”, “salt & pepper skull”
- Brown tumors: not really tumors or malignant. They are radiolucent areas of increased osteoclast activity from abnormal bone metabolism. Rare – associated with hyperparathyroidism
19
Q
Pagets Disease
A
- Chronic inflammatory remodeling of bone
- 3 Phases: Early lytic, Mixed, Osteoblastic (Dense, sclerotic bone changes late)
- Pelvis, skull, spine, tibia (spares fibula)
- Thickening of cortex
- Thick, sclerotic traebeculum
- Bone gets bigger overall (“hat don’t fit”)
- Pagets disease: bones get hairy looking! Scalp gets much thicker; IT SPARES THE FIBULA (generally)
20
Q
Avulsion fracture
A
-Avulsion fx’s are caused by sudden torque on the ligaments. The ligament stays intact but pulls a piece of bone away. If small piece of bone pulled off, commonly called a “chip fracture”
21
Q
Pathologic fractures
A
Fracture occurs because bone is weakened by underlying process:
- Bone tumor
- Bone cyst
- Metastasis
- Lytic or sclerotic changes
22
Q
erosive arthritis: rheumatoid arthritis
A
- Narrowed joint spaces
- Periarticular erosions
- Osteopenia
- Subluxation
- Radiocarpal erosion
- Ulnar deviation
23
Q
Osteoblasts
A
- Bone (matrix) formers: increase density, sclerotic appearance
- Reparative: heals fx’s,
- Reactive: produce bone in cortex (periosteal lesions) or medullary cavity
24
Q
Osteoclasts
A
- Bone (matrix) resorbers: remove, destroy: decrease density, lucent appearance
- Can remove bone at 20x rate of formation
- “make room” for tumors, infection
25
soft tissues
- Edema
- Effusions in joint
- Fat pad - blood or fluid in fat space (elbow)
- Calcifications in soft tissue - outside of bone, joint
- Masses
- Gas
- Foreign bodies
26
Codman's triangle
Characteristic of aggressive periosteal reaction
- Malignancy, osteomyelitis
- Spicule of bone at edge of lesion, lifts periosteum
- Forms a triangle with bone cortex
27
periosteal reactions
Osteoblasts respond to periosteal insult - localized
Non-aggressive – solid
- Fx healing, repetitive trauma (child abuse)
- Neoplasms (usually benign)
- Osteomyelitis, indolent infections
Aggressive - mixed pattern → usually bad
- Malignant tumors, infection
- Interrupted pattern, onion skin, spiculated, sunburst
- Codman’s triangle
28
septic arthritis - pyogenic
- Hematogenous or local process
- Risks: IVDU, trauma, prosthesis, steroids
- Monoarticular - knee, hip, hands - any joint
- Staph, GC
- Articular cartilage destruction
- Rapid progression
- Polyarticular - rare
- Red, hot, painful joint. Plain film changes are late, but order one first.
- May see subchondral erosions, periosteal reaction (above)
29
Alignment - dislocations
- Joint space disruption
- Complete, partial (subluxation)
- Risk for fx, vascular injury
- Reduction (Manually move dislocated bone back into place, Realigning fractures prior to immobilization)
- Post-reduction films – check for placement, fx during reduction
- Reduction is moving dislocation back into place
- What is attached to the bone? A ton of stuff!! Vasculature, etc.
30
description of fractures
Open or closed?
-Open = compound
Must look at all views!
Location
- Which bone(s)?
- Where in the bone?
- “Head” proximal
- Proximal, middle, distal third of shaft, neck
- Intra-articular?
Number of fragments
- Simple (2)
- Comminuted (>2)
Direction of fx line
-Transverse, oblique spiral, longitudinal
Alignment
- Displaced
- Angulated
- Distracted
- Shortened
- Impacted, depressed
- Rotated
Special fractures
- Torus, greenstick, compression
- Name of fracture type
31
Osteomyelitis
- Soft tissue swelling, Hx
- Focal lucent or destructive areas within the bone
- Focal periosteal reaction
- Acute, subacute or chronic
- Plain film poor, but initial test
- MRI best, bone scan next
- Bone biopsy diagnostic
32
MRI indications
- Spinal cord injuries
- Occult fractures (Hip (elderly), scaphoid)
- Tendons/Ligaments/ Soft Tissue (MR Arthrography - contrast study of joints, Pre-op evaluation)
- Certain complex fractures, infections
- Bone marrow abnormalities
- Avascular necrosis
33
osteoporosis
- diffuse loss of bone density
- Decreased bone mass: generalized
- Women > men
- Elderly, post-menopause ETOH, steroids, smokers, renal failure, GI Dz, debilitation
- Plain film, BMD/DEXA, CT
- Risk for pathologic fracture
- BMD: bone mineral density test
- DEXA: dual energy xray absorptiometry
34
reading a film
General Approach:
```
AABC’S
-Adequacy
-Alignment
-Bones + Periosteum
-Cartilage (joint space)
Soft tissue
```
35
Bones: increased density
Generalized increased density
- Multiple/diffuse osteoblastic metastases – prostate CA
- Osteopetrosis (“marble bone dz”)
Focal increased density
- Impacted fracture, fracture healing
- Localized osteoblastic metastases
- Avascular necrosis (Late finding, May see “crescent lucency” from a subchondral fracture)
- Paget’s disease (late finding)
36
bone tumor
- Periosteal reaction
- Aggressive
- Hyperdense bone
- Organized mass with clear margins
- Codman’s triangle
- CT next test for: periosteal reactions, lucencies, increased density lesions
37
Fracture Healing
Affected by: Pt age/health, the site, number of fragments, immobilization, blood supply to site
Inflammatory Phase
- 5 to 7 days
- Hematoma formation
Reparative Phase
- Callus formation
- 4 to 40 days
Remodeling Phase
- 70% of healing time
- Can last up to one year
- Callus is converted into bone
38
fractures: alignment
Describe position or movement of distal segment relative to proximal
- Displacement: Left or right movement away from mid-diaphyseal axis line
- Angulation: angle away from normal axial line (Posterior or Anterior (dorsal or ventral/volar), Medial or Lateral (varus or valgus))
- Rotated (internal or external)
- Distracted
39
Number and types of bones
- 206 bones in the body
- Long bones - length > width
- Short (cuboidal) bones - wrist, foot
- Flat bones - skull, illiac bone, scapula
- Sesamoid bones - “accessory ossicles” (Small, rounded bones located in tendons (
- Irregular bones - vertebral bodies
40
Charcot joint
- hypertrophic form
- denervation of joint
- micro fx's, bone fragmentation
- joint destruction
- pt w/ DM most common
41
Delayed fracture complications
-Delayed union, Malunion, Nonunion
-Osteomyelitis – bone infection
-Avascular necrosis
-Myositis Ossificans - after blunt trauma
-Compartment syndrome of right forearm
Fasciotomy
-KNOW COMPARTMENT SYNDROME!!!! They don’t need all 5 Ps for them to have compartment syndrome
-Malunion → bad union, nonunion → not coming together
42
osteoarthritis (DJD)
- Narrowed joint spaces
- Osteophytes & Spurs
- Subchondral sclerosis
- Subchondral bony cysts
- Primary most common
- Secondary (Usually after trauma, Young, unilateral)
43
erosive arthritis: ankylosing spondylitis
- Syndesmophytes: bony bridges join corners of vertebrae
- “Bamboo spine”
- Sacroiliitis
- Erosions at the corners of vertebral bodies
- SI joint fuses first - ascends spinal column
- “Bamboo spine” on AP: syndesmophytes fuse anteriorly
- Sacroiliitis is hallmark, with HLA-B27 positive
- SACROILITIS
- Syndesmophytes connect the vertebral bodies to each other (happens anteriorly mostly)
- HLA-B27 = rheumatologic blood test
- Disease of young men
- Measure progression with angle that they’re bent over
44
Imaging modalities
- Plain Films – initial test for bones (Trauma, pain, edema, decreased ROM, FB, Always at least AP, Lateral (orthogonal 90deg), Oblique is initial 3rd view (hand, wrist, ankle, foot, etc), Special views)
- CT Scan
- MRI
- Nuclear Imaging
45
Pseudofractures - fake outs
- Nutrient vessels
- Sesamoid bones/ Accessory Ossicles (Smooth, round, sclerotic edges, Predictable locations: feet, hands, elbows, wrists, knees)
- Overlapping adjacent bones
- Skin folds
- Distinguishing characteristics: Location, well corticated margins, no disruption, not the tender area, see on one view only
- Sesamoid bones are almost always roundish and they are smooth. They are also in typical places: feet, hands, elbows, writs, knees
46
is the film adequate
- Name, date, L&R label, all views?
- Pt properly positioned (“True” lateral or “true” oblique? All structures seen in anatomical alignment? Special views taken properly?)
- Must know normal radiographic anatomy to evaluate normal alignment and position
47
Acute fracture complications
- Compartment Syndrome (Pulselessness, pallor, pain, parasthesia, paralysis (5 P’s))
- Local Infection - skin cellulitis
- Fat Embolism
- Hemorrhage
48
Stress fractures
-Small breaks, repetitive stress, exercise or impact
-Most common in the
foot, lower leg
-Initial xray often neg
-Repeat xray → solid periosteal reaction in 10-14 days
-Bone scan
-MRI
-Plain xray may show findings in 10-14 days (or longer)
-Bone scan may be positive in 6-72 hours
-Runners, gymnasts, army
49
primary bone tumors
- Pt age, location helps DDx: must biopsy
- 0-10yrs – Ewing’s sarcoma, neuroblastoma
- 10-20yo, long bones (Ewing’s sarcoma (shaft), Osteosarcoma (epiphysis: growth areas))
- 20-40yo (Osteosarcoma, Giant cell tumor (epiphysis))
- >40yo (Chondrosarcomas: Long bones 45%, pelvis 25%; Thoracic spine, Consider metastases from distant primary)
50
Malunion
- Fracture not healed
- Residual angulation
- Callous not completely formed
- Why? (Delayed immobilization, Poor reduction, Surgery not available, Surgical error, Non-compliance, Systemic illness)
51
Avascular Necrosis
- Bone death d/t diminished blood supply
- Femoral head, humeral head, scaphoid, talus (Kids - hip pain)
- Increased density, sclerosis, bony collapse, patchy or crescent lucencies
- Fractures, steroids, sickle cell, collagen vascular Dz, Legg-Calve-Perthes Dz
- Plain film sensitive late
- MRI is imaging study of choice, bone scan next
