Musculoskeletal 2 Flashcards
Lunate dislocation
-FOOSH or direct blow to the palm
-Lateral view is key
-“spilled teacup” – lunate rotates toward palm
-Carpals remain aligned with distal radius
-Most severe of carpal dislocations
-Check median nerve
-Lunate rotates toward the palm but all the other carpal bones remain aligned
-The median nerve runs right past this bone
-On AP view - carpals overlap, lose
carpal alignment “arches”, lunate
appears triangular and scaphoid short on AP; lateral “crescent moon”
the wrist
3 views - standard
-PA, lateral, oblique
Special views
-All include distal radius
and ulna, proximal
metacarpals
Carpal bone anatomy,
-relationships key
Humerus fracture
- Surgical neck most common single site
- Impaction, multi sites common
- Fx anatomic neck = risk of avascular necrosis
- In combo with or mimics dislocation
- May require surgery
- Surgical starts with an S and so does strangle
- Avascular necrosis comes from fx at anatomica neck
components of the upper extremity
- Shoulder (Scapula, Clavicle)
- Humerus
- Elbow
- Radius/Ulna
- Wrist
- Hand, Fingers
Gamekeeper’s thumb
- Acute injury is also called skier’s thumb, breakdancer’s thumb
- Disruption of ulnar collateral ligament with avulsion fracture at base of proximal phalanx
Acromioclavicular separation
Type (Grade) I
-Partial tear of AC with no displacement
Type II
-Disruption of ACL and widening of joint
Type III
-Disruption of AC and coracoclavicular ligaments
Normal AC joint < 8 mm
Normal coracoclavicular distance < 13 mm
- Weight-bearing views helpful
- Type 1-3 most common
- Type 4-6 complex
Distal radius fractures
*Hutchenson’s or “Chauffeur’s” Fx -Intraarticular, oblique Fx of radial styloid -Scapholunate widening common -No angulation
*Die-punch or Lunate-load Fx -Intraarticular, medial distal radius fx, impaction of lunate on radius -Scapholunate spacing often disrupted \+/- ulnar styloid fx too
elbow dislocation
-3rd most common joint dislocation in adults
-Most common joint dislocation in kids
-Hyperextension
-90% are posterior
-1/2 have associated fx
-Vascular compromise,
nerve injury, hemorrhage, entrapment
Colles fracture
- Most common injury to the distal forearm
- FOOSH
- May be impacted
- Distal radius has dorsal angulation/displacement on lateral view
- 50% also have an ulnar styloid fracture
Inspect the radial head
- Most common elbow fracture in adults
- Adolescents common
- FOOSH injury: “fall on outstretched hand” - arm is extended
- Can be subtle! (Mechanism, Sx’s, Radiocapitellar line? Posterior Fat Pad?)
Anterior shoulder dislocation
- 95% of shoulder dislocations are anterior
- Arm held in abduction, external rotation, extension (Cannot internally rotate)
- Humeral head out, anterior and inferior to glenoid
- More displacement than posterior dislocation
- Humeral head fixed in external rotation - greater tuberosity is lateral (in profile)
Scaphoid (navicular) fracture
- Most commonly fractured carpal bone in adults
- Rare in children
- FOOSH w/ extreme dorsiflexion of hand, snuffbox tender
- Midportion (“waist”) fx = risk for AVN of proximal pole
- Scaphoid view
- Xrays initially neg in up to 20% who have a fracture
- VERY IMPORTANT!!!
- Why is this key? VASCULAR SUPPLY
- If you break your scaphoid completely at the waist, you can have avascular necrosis of proximal pole
Galeazzi fracture/dislocation
-Radius Fx at distal 1/3 w/ distal ulnar dislocation
-Ulna dislocated at
radio-ulnar and
carpal-ulnar joints
-Unstable - requires
ORIF
Scapholunate dissociation
- “David Letterman” sign – space between front teeth.
- SL ligamentous disruption
- Scaphoid rotates - seen on end on AP view
- Very subtle injury but if you miss it, the person loses function
- N means navicular which is the same as scaphoid
triquetrum fracture
- 2nd most common
- FOOSH, dorsal pain
- Usually avulsion fx dorsal surface
- Triquetrum is the most dorsal carpal bone seen on lateral view
“swan neck” deformity
- Fixed extension at PIP
- Flexion at DIP (Follows untx’d)
- Volar plate and Mallet
- Finger fractures (Autoimmune arthritis)
- Autoimmune arthridities: rheumatic arthritis, psoriatic arthritis, SLE arthritis, scleroderma
The elbow
- Elbows are special…
- AP, Lateral - standard views
- Special Views (Medial, Lateral oblique, Capitellum (capitulum))
- Reading elbow films (Fractures easily missed, Organized approach reduces miss rate)