Wrist and Hand Imaging and Complaints Flashcards
Differential diagnosis of the wrist and hand
- Radiograph: initial study for all hand/wrist Fx and dislocations
- MRI/MRA: occult or stress Fx (scaphoid, lunate), staging osteonecrosis, post-traumatic arthritis, ligamentous injuries such as TFCC tears
- CT: complex Fx (hook of hamate, scaphoid), distal radioulnar joint or thumb dislocation, intra-articular Fx
- Ultrasound: tendon injury, nerve lesion, ganglion cyst, & soft tissue masses
Appropriate imaging for wrist trauma/1st exam
- X-ray including at least a PA, Lateral, & semi-pronated oblique
Appropriate imaging for suspect acute distal radius Fx, radiographs normal, next procedure
- Cast & repeat x-ray first in 10-14 days or MRI wrist without contrast
Appropriate imaging for comminuted, intra-articular distal radius Fx on radiographs, surgical planning
- CT west without contrast
Appropriate imaging for suspect acute scaphoid Fx, 1st exam
- X-ray wrist
Appropriate imaging for suspect acute scaphoid Fx, radiographs normal, next procedure
- Cast & repeat x-ray wrist in 10-14 days or MRI wrist without contrast
Appropriate imaging for suspected occult scaphoid Fx, initial & repeat x-rays after 10-14 days of casting normal, continued clinical suspicion of scaphoid Fx, next prcedure
- MRI wrist without contrast
- CT wrist without contrast if MRI cannot be performed
Appropriate imaging for suspect distal radioulnar joint subluxation
- X-ray wrist & CT wrist without contrast bilateral
Appropriate imaging for suspect hook of hamate Fx, initial radiographs normal or equivocal
- X-ray wrist include supinated and carpal tunnel views
- CT wrist without contrast
Appropriate imaging for suspect metacarpal Fx or dislocation
- X-ray hand
- CT hand without contrast (if strong concern following radiograph)
Appropriate imaging for suspect phalangeal Fx or dislocation
- X-ray hand or finger include a PA, lateral, & externally rotated oblique views
Appropriate imaging for suspect thumb Fx or dislocation
- X-ray thumb include AP or PA, lateral, & rotated oblique
Appropriate imaging for suspect gamekeeper injury (thumb MCP metacarpophalangeal ulnar collateral ligament injury)
- X-ray thumb include PA & lateral view
- MRI thumb without contrast (if no Fx in x-ray)
- US thumb (alternative to MRI)
Appropriate imaging for chronic wrist pain with or w/o prior injury, best initial study
- X-ray wrist
Appropriate imaging for routine radiographs normal or non-specific persistent Sx, next study
- MRI wrist without contrast
Appropriate imaging for routine radiographs normal or non-specific suspect inflammatory arthritis, next study
- MRI wrist without & with contrast
Appropriate imaging for radiographs normal or non-specific arthritis, exclude infectious, next study
- Aspiration wrist
Appropriate imaging for ulnar sided pain, normal or non-specific radiographs, next study
- MRI wrist without contrast
- MR arthrography wrist
Appropriate imaging for radial sided pain, normal or non-specific radiographs, next study
- MRI wrist without contrast
Appropriate imaging for x-ray normal, suspect Kienbock’s disease (avascular necrosis of lunate), next study
- MRI wrist without contrast
Appropriate imaging for palpable mass or suspected occult ganglion cyst, normal x-ray, next study
- MRI wrist without contrast
- MRI wrist without & with contrast
- US wrist (MRI alternative)
Appropriate imaging for pain for more than 3 wks, suspect occult Fx or stress Fx, x-ray non diagnostic, next study
- MRI wrist without contrast
- CT wrist without contrast
Appropriate imaging for x-ray shows old scaphoid Fx, evaluate for union, next study
- MRI wrist without contrast
- CT wrist without contrast
Appropriate imaging for suspect carpal tunnel syndrome
- X-ray wrist
Routine radiograph views of the wrist & hand
- PA
- Lateral
- Oblique
- Other: ulnar or radial deviated views; fist view; scaphoid view; carpal tunnel view
Describe Gilula 3 carpal arcs
- 1) proximal curves of the scaphoid, lunate, triquetrum
- 2) distal surfaces of the same bones
- 3) proximal curves of the capitate & hamate
Why is there a higher incidence of aseptic necrosis & nonunion noted with fractures on the side of the scaphoid
- because no blood vessels enter the proximal pole of the scaphoid
Describe Terry Thomas sign
- gap between the scapholunate
Clinical signs of a scaphoid fracture
- Snuff box tenderness
- Scaphoid tubercle tenderness (volar side of wrist, extend wrist to palpate)
- Longitudinal compression (handshake with overpressure, radially deviate to compress)
- All 3 present = 100% SN and 74% SP
Describe radial inclination
- Angle between one line drawn perpendicular to the long axis of the radius & another line drawn from the top of the radial styloid to the ulnar border
- <15º relative indication for distal radius fracture operative management
- Normal = 21-25º
Describe ulnar variance
- Relates to the lengths of the distal articular surfaces of the radius & ulna
- Positive = play a role in TFCC thinning
- Negative = suspect Kienbock’s disease
- Neutral
Describe a phalangeal fracture
- Fx of the middle & proximal phalangeal shafts may be classified as stable, unstable, or intra-articular
- MOI: more than 50% of hand Fx are work related; avulse Fx occur when a distraction stress overcomes the tensile capacity of the ligament to stabilize the joint
- Imaging: radiographs are sufficient for diagnosis
Describe a boxer fracture
- 5th metacarpal fracture
Describe thumb metacarpal fracture: Gamekeeper’s thumb and Bennett’s fracture
- Bennett’s = intra-articular Fx/dislocation of the base of the thumb; Gamekeeper’s = common injury at the thumb’s metacarpophalangeal joint whereby a valgus force disrupts the ulnar collateral ligament & may avulse bone
- MOI: axial loading or direct trauma
- Imaging: Difficult to diagnosis with standard radiographic projections; additional oblique views, fluoroscopy, or CT may be necessary
Describe a Rolando fracture
- A 3 part or comminuted intra-articular fracture/dislocation of the base of the thumb (proximal first metacarpal)
- Can be thought of as a comminuted Bennett fracture
MRI indications for the wrist and hand
- TFCC tears/degeneration
- Scapholunate or lunotriquetral interosseous ligament tears
- Dorsal & volar extrinsic wrist ligament abnormalities
- Fx of distal radius, scaphoid, & other carpal bones
- Soft tissue injury
- Complications due to scaphoid Fx
- Ganglion cyst
- Osteonecrosis
- Guyon’s canal syndrome, carpal tunnel, nerve sheath tumors
- Flexor & extensor tendon abnormalities
- Osteochondral & articular cartilage abnormalities
MRI wirst & hand ABCDS
- Alignment/anatomy: scaphoid most fractured
- Bone signal: proximal pole of the scaphoid & lunate
- Cartilage: TFCC best seen on coronal image
- eDema: confirm that it is edema, seen as an intermediate signal on anatomy defining sequences & a high signal on fluid sensitive sequences
- Soft tissue
Describe extrinsic and intrinsic tendons
- Extrinsic: connect radius & unla to carpals, carpals to metacarpals
- Intrinsic: connect carpals to carpals
Quick tips for tendons, neural structures, & muscles
- Tendons: tendon sheath can fill with fluid & show high signal intensity (white) on T2 weighted images indicating inflammation
- Neural structures: cross section & axial image view
- Muscles: intermediate signals
Describe osteonecrosis of the lunate: Kienbock’s disease
- Usually affects the dominant wrist in men 20-40 yrs
- Imaging: MRI is most sensitive to marrow changes consistent with osteonecrosis in the early stages of the disease when radiographs are nondiiagnostic
CT imaging indications for the worst & hand
- Trauma
- Displaced distal radial fractures or carpal fractures
- Osteochondral lesion if MRI not available
- Any study an MRI can do if MRI is contraindicated
CT order of most radiolucent to most radiopaque
- Air = black
- Fat = gray/black
- Water = gray
- Bone = gray/white
- Metal = white
What could be a potential cause for a hook of hamate fracture
- Usually happen to athletes who grip a bat or club
Describe a CT arthrogram for TFCC tear
- Leakage of contrast from the radoiocarpal joint into the distal radioulnar joint indicates a tear of the TFCC
- Ulnar variance can be assessed with radiograph; Pos. = describes where the distal articular surface of the ulna is more distal when compared to the articular surface of the radius
Describe children primary ossification centers in the wrist & hand
- Capitate: 1-3 mo
- Hamate: 2-4 mo
- Triquetral: 2-3 yrs
- Lunate: 2-4 yrs
- Scaphoid: 4-6 yrs
- Trapezoid: 4-6 yrs
- Pisiform: 8-12 yrs
Describe children secondary ossification centers in the wrist & hand
- Metacarpal heads fuse at 14-19 yrs
- Phalangeal bases fuse at 14-19 yrs
