Knee X-ray positioning
How to position for each of the 6 knee X-ray views: where the patient goes, where to centre, which receptor and distance to use, and what a good image looks like.
By the ScanFlo Editorial Team · Updated
In this section · X-ray positioning
- X-ray positioning guides
- Skull positioning
- Face & sinuses positioning
- Soft tissue neck positioning
- C-spine positioning
- Chest positioning
- Shoulder positioning
- Humerus positioning
- Elbow positioning
- Forearm positioning
- Wrist positioning
- Hand positioning
- T-spine positioning
- Abdomen positioning
- L-spine positioning
- Sacrum & SI joints positioning
- Pelvis positioning
- Hip positioning
- Femur positioning
- Knee positioning
- Tibia & fibula positioning
- Ankle positioning
- Foot positioning
X-ray positioning/Knee
The routine knee views are Knee AP and Knee lateral. Knee intercondylar (tunnel), Knee lateral (horizontal beam), Knees AP standing and Patella axial (skyline) come in when you need to answer a particular question, or when the patient can't manage a routine view. Each guide walks you through the set-up step by step, with a short video, exposure settings for different patient sizes and what a good image should show.
A radiographer is still checking these guides.
Routine views
Extra views
All views in this region
- Knee AP
- Knee lateral
- Knee intercondylar (tunnel)
- Knee lateral (horizontal beam)
- Knees AP standing
- Patella axial (skyline)
Quick reference
Where to centre, how far and which receptor, for every knee view at a glance. Open a guide for the full set-up.
| Projection | Centre on | SID | Receptor | Breathing |
|---|---|---|---|---|
| Knee AP | 1 cm below the apex of the patella | 100 cm | 18×24 portrait | No breathing instruction needed |
| Knee lateral | the medial femoral condyle | 100 cm | 18×24 portrait | No breathing instruction needed |
| Knee intercondylar (tunnel) | the knee joint | 100 cm | 18×24 landscape | No breathing instruction needed |
| Knee lateral (horizontal beam) | the knee joint | 100 cm | 18×24 portrait | No breathing instruction needed |
| Knees AP standing | between the knees at the joint line | 110 cm | 35×43 landscape, grid | No breathing instruction needed |
| Patella axial (skyline) | the patella | 100 cm | 18×24 landscape | No breathing instruction needed |
Mistakes that lead to repeats
- Patella off-centre on the knee AP: rotate the foot in slightly.
- Condyles separate on the knee lateral: pad the ankle; square the knee.
- Fossa closed on the knee intercondylar (tunnel): adjust the angle.
- Knee bent on the knee lateral (horizontal beam): use the horizontal beam.
- Weight on one leg on the knees AP standing: equal weight on both feet.
- Joint not open on the patella axial (skyline): adjust flexion.
Common questions
- Which knee views are routine?
- Usually Knee AP and Knee lateral.
- What distance (SID) do knee X-rays use?
- Anywhere from 100 to 110 cm, depending on the view. Each guide gives the exact figure.
- Do knee X-rays need a grid?
- Only Knees AP standing needs one; the rest are taken without a grid.
Try it in ScanFlo: the ScanFlo XR X-ray Room, coming soon, lets you set up every knee projection in a 3D room and score your positioning. See ScanFlo XR →