Knee - Horizontal Ray Lateral

Radiographic Positioning

Adult

Other related pages of interest Applied Radiography Radiographic Anatomy Radiographic Protocols

Name of projection	Knee - Lateral - Horizontal Ray (Trauma)
Area Covered	Distal femur, proximal tibia & fibula, patella, and knee joint.
Pathology shown	Any fractures, fluid/fat levels (lipohaemarthrosis), soft tissue abnormalities see snow globe effect and lateral knee radiography
Radiographic Anatomy	Knee Radiographic Anatomy
IR Size & Orientation	24 x 30cm Landscape
Film / Screen Combination	Detail (CR and DR as recommended by manufacturer)
Bucky / Grid	No
Filter	No
Exposure	60 kVp 8 mAs
FFD / SID	100cm
Central Ray	CR directed horizontally 2.5cm distal to apex of patella
Collimation	Collimate on the sides to the skin margins Include maximum amount of femur and tibia / fibula
Markers	Distal and Anterior Marker orientation AP
Shielding	Gonadal (check your department's policy guidelines)
Respiration	Not applicable
Positioning	Patient supine on the X-ray table or barouche Place vertical IR against medial aspect of knee centred to level of knee joint Place support under knee to centre knee to IR Direct CR horizontally and perpendicular to IR 2.5cm distal to apex of patella
Critique PACEMAN	Positioning Area Covered Collimation Exposure
Special Notes	A horizontal beam true lateral of the knee without knee flexion demonstrates subpatella bursa and associated fat pads for possible displacement or presence of a fluid level. Effusion is well visualised because of the horizontal ray. Effusion within the articular cavity of the knee is a strong indicator of knee joint pathology. This is also a good projection for possible fracture or dislocation of patella