Ankle - Oblique (Internal)

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Radiographic Positioning


Adult
Other related pages of interest

Name of projection Ankle - Medial Oblique (Internal Rotation)
Area Covered Distal 1/3 of the tibia and fiblua, proximal metatarsals, ankle joint, lateral and medial malleoli
Pathology shownfractures, joint effusion, dislocation, foreign body
Radiographic AnatomyAnkle Radiographic Anatomy
IR Size & Orientation 24 x 30cm
Landscape, divided in two usually fits two ankle projections, use lead masking for unused area
Film / Screen Combination Detail
(CR and DR as recommended by manufacturer)
Bucky / Grid No
FilterNo
Exposure 60 kVp
3.2 mAs
FFD / SID100cm
Central Ray Midway between the malleoli, in line with the medial malleolus
Perpendicular to the IR
Collimation
  • Centre: Midway between the malleoli at the level of the tibiotalar joint
  • Shutter A: Open to include the distal 1/3 of the fibula and the proximal metatarsals
  • Shutter B: Open to include the lateral skin margins
Markers Distal and Lateral
Marker orientation AP
Shielding Gonadal (check your department's policy guidelines)
RespirationNot applicable
Positioning
  • Patient's leg fully extended
  • Lower leg in AP position, toes pointing up
  • Internally rotate entire leg and foot until the long axis of the foot is 45° to the IR
Critique

Positioning
  • The correct positioning is evidenced by
  1. The lateral and medial malleoli are shown in profile
  2. There is some minor imposition of the distal fibula over the tibia
  3. There lateral mortise space is open, as there is no superimposition of the talus over the fibula
  4. The tibiotalar joint space is open

Area Covered
  • Distal 1/3 of the tibia and fiblua, proximal metatarsals, ankle joint, lateral and medial malleoli
Collimation
  • Centre: Midway between the malleoli, in line with the medial malleolus
  • Shutter A: Open to include the distal 1/3 of the fibula and the proximal metatarsals
  • Shutter B: Open to include the lateral skin margins

Exposure
  • Bony trabecular patterns and cortical outlines are sharply defined
  • Soft tissues are visualised
Special NotesThe effect of too little leg and foot rotation
  • The image will look more like a Mortise Ankle view, that is
  • The malleoli will be shown in profile
  • The lateral mortise will be open

The effect of too much leg and foot rotation
  • The medial mortise will be closed
  • The lateral mortise will be closed
  • The sinus tarsi will be shown
  • The fibula will have virtually no talar superimposition