Knee (horizontal beam lateral view)
Citation, DOI, disclosures and article data
At the time the article was created Andrew Murphy had no recorded disclosures.View Andrew Murphy's current disclosures
The horizontal beam lateral view (cross-table lateral) is an orthogonal view of the AP view of the knee requiring little to no patient movement and is hence the lateral projection of choice for acute knee injuries.
This view is the ideal projection to assess the presence of knee joint effusion or lipohemarthrosis as it demonstrates the suprapatellar bursa and associated fat pads for possible displacement or presence of fluid levels from knee pathology 1. Knee pathology can include fracture or dislocation of the femur, tibia, fibula or patella.
the patient is supine on the table/bed
affected knee is flexed slightly ≈ 30° (to the best of patient's ability)
the detector is placed against the medial side of the knee running parallel to the affected leg, often held by the patient or sandbags
the long axis of the femur is running perpendicular to the beam
center to the knee joint 1.5-2.0 cm distal to the apex of the patella or at the tibial tuberosity if the patella is affected by certain injury patterns
superior to include the distal femur
inferior to include the proximal tibia/fibula
anterior to include the skin margin
posterior to include skin margin
35 cm x 43 cm
Image technical evaluation
A true horizontal beam lateral projection will have the following characteristic:
superimposition of the medial and lateral condyles of the distal femur
an open patellofemoral joint space
slight superimposition of the fibular head with the tibia
The distal femoral condyles have distinct features that can be used for differentiation and hence positional errors that can be corrected.
The medial condyle has a medial adductor tubercle, located superior to the medial epicondyle, a bony protuberance that acts as the attachment point the adductor minimus and the hamstrings part of the adductor magnus.
The lateral condyle has the condylopatellar sulcus also known as the lateral notch, a groove in the lateral femoral condyle. The easy way to remember is femoral is flat.
An interactive case correcting lateral knees can be found here
Correcting rotational errors
medial adductor tubercle is posterior to the lateral condyle
rotate the knee externally to bring it anterior
medial adductor tubercle is anterior to the lateral condyle
rotate the knee internally to bring it posteriorly
Abduction and adduction
medial condyle is proximal to the lateral condylar
medial condyle is distal to the lateral condyle
- 1. John Lampignano, Leslie E. Kendrick. Bontrager's Textbook of Radiographic Positioning and Related Anatomy. (2017) ISBN: 9780323399661
- 2. Kenneth L. Bontrager, John P. Lampignano. Textbook of Radiographic Positioning and Related Anatomy. (2014) ISBN: 9780323083881 - Google Books
- 3. Jamie Weir, Peter H. Abrahams. Imaging Atlas of Human Anatomy. (2011) ISBN: 9780723434573 - Google Books