Knee series

The knee series is a set of radiographs taken to investigate knee joint pathology, often in the context of trauma. It usually comprises an AP and lateral projection, although other non-standard, modified projections can be used for specific indications.

See also knee radiograph (an approach).


Knee radiographs are indicated for a variety of settings including 1,2:


Standard projections
  • AP view

    • demonstrates the distal femur, proximal tibia/fibula and the patella in the AP position

    • ideal projection to asses the tibial plateau and tibiofemoral alignment  

  • horizontal beam lateral view

    • orthogonal projection to the AP, routinely done in trauma horizontal beam to better demonstrate any joint effusions

    • ideal projection to asses lipohaemarthrosis

    • used to examine the location of the patella and the patency of the patella tendon

Additional projections
  • rolled lateral view

    • often performed on bed bound patients with suspected arthritis

    • orthogonal view of the AP projection

    • demonstrate the joint space, yet sacrifices any assessment of fluid levels
Radiographic views
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Article Information

rID: 42332
Section: Radiography
Synonyms or Alternate Spellings:

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Cases and Figures

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    Figure 1: radiographic anatomy - AP
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    Figure 2: radiographic anatomy - lateral
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    Figure 3: radiographic anatomy - Sunrise view
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    Figure 4: AP view of a fractured patella
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    Figure 5: horizontal beam lateral view of a fractured patella
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    Figure 6: horizontal beam lateral demonstrating lipohaemarthrosis
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    Figure 7: AP view used to asses the tibiofemoral line
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