Musculoskeletal System X-Ray Flashcards
MSK X-Ray Systematic Approach (6 Steps)
- Bone structure alignment
- Joint space eval
- Bone cortex integrity
- Medullary bone texture
- Soft tissues
- Visible abnormalities
Joint Alignment considerations (2)
- Smooth cortical outline (if jagged, fx)
- Typical bone articulation (if unaligned, dislocation)
- Joints c adequate space (if uneven or narrowed, arthritis. if widened, dislocation)
Cortex Evaluation
- Follow cortical outline around the edge of each bone, including in joint space
- Cortex continuity directly relates to bone integrity
- Cortical outline disturbances can indicate fracture
Identify Pathology
Osteoporosis or Osteopenia
Significant Findings
- Relatively transparent bone density (compare c picture here)
- More likely to fx
Identify pathology (present in both pictures)
Widened Joint Space (consistent c potential dislocation or fx)
- Significant Findings*
- Abnormal separation between joints (R image is too posterior, L image is completely disarticulated)
Soft Tissue Observations on X-ray (4)
- Sprain
- Bursitis
- Infection
- Bleeding into joint
Identify Pathology
Olecrenon Bursitis
- Significant Findings*
- Congruous transparent tissue shadow around elbow joint c regular edges
Comparison View (explaination, 2 examples)
Explanation: Since each body has normal varients, comparing against self is the best basis for identifying normal varient vs pathology
Examples:
- Right vs. Left; Cortical abnormality of injured side will appear differently than uninjured side
- New vs. Old; This is great to show progress of conditions like stress fx or lytic lesions
Lytic Lesion (def, eval method)
Definition: Malignant process where lesions eat away at bone
Evaluation: Comparison of new and old films is a good indicator of disease progression
Long Bone Fractures (4 types, descriptions)
- Transverse: fx line perpendicular to long bone direction
- Oblique: fx line passes at an angle to long bone direction
- Comminuted: fx in >2 segments, fragmented
-
Spiral: fx line spirals/twists around long axis of bone
- Often indication of abuse
Identify Pathology
Transverse Tibial Fracture
- Significant Findings:*
- Fx crossing perpendicular to cortical outline
Explain Pathology (not letting you get away that easily)
Fibula: While fibula does not have a straight fracture line transversing the bone, there are only two pieces of bone. Therefore, this is a transverse fx
Tibia: There are multiple bone fragments in the distal portion of the bone. This is best noted on the highly irregular right cortical border in Film B.
Identify Pathology
Oblique Femural Fx
- Significant Findings:*
- Singular fx at an angle to the cortical border
Explain Pathology
Femoral shaft is in >2 fragments. All fragments are limited to mid-upper femoral shaft
Identify Pathology
Spiral Tibia and Fibula Fractures
Significant findings
- Twisting oblique fracture lines on both tib and fib (fibula is most noted on the left-most picture)
- Decreased ankle mortise
- *Note
- Often result of limb-twisting. This is almost exlusively restricted to physical abuse MOIs
Identify Pathology
Spiral Tibia Fracture
- Significant findings*
- Twisting oblique fracture lines on tibia
Note
Often result of limb-twisting. This is almost exlusively restricted to physical abuse MOIs
Displacement (define, describe in context of long bone fx)
Definition: Loss of bone alignment
Description: Usually a result of angulation, bone will not “fit” appropriately into joint. There is a high liklihood for associated dislocation
Shortening (describe in context of long bone fx)
When a full-thickness fx occurs, the bone displacement may create overlap between disconnected segments, making the bone appear shorter. The distal fragment will migrate
Example: Identifying quality of hip fx is that affected leg will appear shorter than unaffected leg, both on x-ray and phys examination
Identify Pathology
Displaced Oblique 4th Metatarsal Shaft Fx
Signifiant Features:
- discontinuity of cortical border
- loss of alignment; movement of distal fragment
- *Note
- Little to no shortening, likely due to muscular and ligamentus integrity of the foot in addition to lack of repeated pressure application. (That is my guess, at least. History will reveal more)
Identify Pathology
Transverse Tibial and Spiral Fibular Fractures
Significant Findings:
- Incongruous cortical borders
- Displacement of distal fragments
- Shortening of long bones
- *Note
- Fxs stabalized c a locked reamed intramedullary nail, shown
Pathological Fractures (definition, most common example)
Definition: Fractures that arise in bones weakened by disease
Most Common: Osteoperosis-based fractures
Identify Pathology and Explain Pathogenesis
Left Medial Midshaft Humeral Pathological Fx
Pathogenesis
- Pt presented with metastatis cancer (in this case, prostate)
- Metastses migrated to internal L humerus (via lymphatic metestatic disease), where it created moddled diaphyseal appearance c irregular cotical erosion (A and B)
- 2 mo later, pt presented c complete transverse pathological fx thru midshaft humerus (C and D)
Significant Findings
- Mottling and fx noted above
- Decrase in longbone opacity between A/B and C/D, a sign of osteoporsosis/osteopenia
Avulsion Fracture (Definition, X-Ray Landmarks)
Definition: Bone fragment that is pulled off by a tendon
Landmarks: Change in color beyond line of avulsion fx, even without displacement. Think about tendonous attachment points and look there carefully, especially with corresonding history
Identify Pathology
Avulsion Fx to Ulnar Base of 1st Proximal Phalynx and MCP Joint
Significant Findings
- Small differently colored bone fragments (not really displaced here)
- Fx location near ulnar collateral ligament attachment
- Thenar eminence swelling
- *Note
- This was probably due to forced hyperabduction of a flexed thumb
Identify Pathology
Comminuted Clavicular Fx
Significant Findings
- 3 bone fragments in middle third of clavicle
- Clavicular shortening
- No apparent shoulder dislocation!
- *Note
- Nonoperative management due to fx nondisplacement
Identify Patholgoy
Anterior Right Shoulder Dislocation
Significant Findings
- Medial humeral head displacement (compared to glenoid fossa)
- Humeral head location inferior to coracoid process
Identify Pathology
Right Anterior Shoulder Dislocation
- Significant Findings*
- Glenoid inferior to its normal position in the center of the “Y” formed by the scapula
- *Note
- This is a “scapular Y view” x-ray. Good for ID of shoulder dislocation. Glenoid should fall in center of Y
Identify Pathology
Posterior Shoulder Dislocation
Note
- Highly difficult to dx from AP views alone, as glenoid moves posteriorly but usually does not displace superiorly or inferiorly. Thus, bone may appear to be in place
- Best view for dx: transcapular Y view (not pictured)
Identify Pathology
Slightly Oblique Midshaft Humeral Fx
Signifiant Findings
- Fracture that is not completely perpendicular with cortical border, but is only two pieces (see chipping in medullary area)
- + Displacement, - Shortening
- While overexposed, bone still seems to exhibit opacity
Identify Pathology
Displaced (2 part) Comminuted Proximal Humerus Fx
Significant Findings
- Complete separation at surgical neck
- + Shortening, + Displacement
- No dislocation of glenoid from GF
Note
- While we did not learn Neer Classification System at this time (that dictates the “2-part” of this dx, the significance of this fracture is still present
Fat Pad Sign (Definition, Description)
Also called “Sail Sign”
Definition: Typical X-ray presentation due to displacement of joint fat pad from bleeding into a joint
Description: Elevated and visible change in soft tissue coloration bordering bone. The disclorations are triangular or “sail-shaped,” with the bone parallel to one of the triangular borders
Identify Pathology
Radial Neck Impaction fx
Signifiant Findings
- Anterior and posterior fat pad signs (white arrows)
- Sharp, angular change in cortical border near black arrow
Identify Pathology
Gartland Type II Supracondylar Fx
- Significant Findings*
- Growth plate present on humerus
Note
- This pediatric fx is typical of falling on an extended elbow, usually from some height (monkey bars, beds)
- Type II indicates displacement but intact cortex
- The most revealing image for this fx is usually a lateral semi-flexed position. This will reveal an anterior sail sign c elevated fat pad
Identify Pathology
Colles Fx
Significant Findings
- 100% dorsally displaced distal radius and ulna
- Volnar angulation
- + Shortening, + Displacement
- Two transverse fx
Note
- MOI = FOOSH (falling on outstretched hand)
Identify Pathology
Distal Greenstick Radial Fx, Distal Full-thickness Ulnar Fx
Significant Findings
- Minimal angulation and no displacement (pediatric fx, flexible bones)
- Greenstick fx - partial thickness - better visualized in lateral view. Bulges from dorsal aspect
- Growth plates present
Identify Pathology
Scaphoid Fracture
- Significant Findings*
- Line through middle 1/3 of scaphoid
Note
- This image was taken 2 weeks after FOOSH (fall on outstretched hand) injury. Initial xrays were normal but lack of circulation precipitating avascular necrosis caused a change in xray appearance
Identify Pathology
Angulated 4th and 5th Metacarpal Neck Fxs
Significant Findings
- Incongruency in cortical borders in 4th and 5th metacarpals
- Angular shape of bone fragments
- Transverse fractures
Identify Pathology
Anterior PIP Dislocation
Significant findings
- Anteriorly deviated middle phalanx
- No associated fx
Note
- Dislocation direction is classified by the distal bone’s location compared to the proximal bone.
- Remember anatomic position puts middal phalynx distal to proximal phalynx
Identify Pathology
Anterior Hip Dislocation
- Significant Findings*
- Femoral head displaced superiorly
Note
- This is to confirm strong s/sx (leg shortening, external thigh rotation)
Identify Pathology
Posterior Hip Dislocation
- Most common type of hip disloation
- Patient will present c internally rotated and flexed hip
Identify Pathology
Comminuted Distal Femoral Fx
Significant findings
- >2 bone fragments in distal femur, represented by incongruous medullary color and uneven cortical borders
- Growth plates present but not involved in fx
Note
- Stabalized via plate fixation
Identify Pathology
Comminuted Patellar Fx
Significant Findings
- Darkened line near white arrow
- Associated soft tissue swelling
Note
- This is a sunrise view of the knee
Identify Pathology
Anterior Knee Dislocation
Significant Findings
- Anterior displacement of tibia
- Alignment of patella and femur are not parallel
- Close proximity of femur and tib-fib
Note
- Dislocations are named for the distal bone’s location in respect to the proximal bone’s location
- This included a bicruciate injury
- Lateral radiograph
Identify Pathology
Lateral Tibial Pleateau Fx
Significant Findings
- Horizontal fx line near yellow arrows
- Nondisplaced lateral bone fragment
Identify Pathology
Nondisplaced Tibial and Fibular Shaft Fxs, Before/After Tx
Significant findings
- Minimal distrubance to cortical borders
- Visible oblique to spiral fxs on tibia and fibula (fibula is more distal)
Note
- Nonoperative tx c nonweightbearing thru week 4 and modified weighbearing weeks 5 and 6. Long leg cast and patellar-tendon bearing casts used.
Identify Pathology
Bimalleolar Fx
Significant findings
- Transverse fx on lateral malleolus
- Oblique, almost avulsion-looking fx on medial malleolus
- Normally presenting ankle mortise
Note
- Unstable fx, requires ortho referral
