Acute Knee X-rays

There is great debate about when to x-ray injured knees. The Ottowa Rules are a reasonable screening tool to avoid unnecessary irradiation of trivial injuries - any of the following requires x-rays:-

Irrespective of the Emergency Room policies any patient attending the Acute Knee Clinic needs simple x-rays.

Projection	Check list
All	Fractures Dislocation Subluxation Soft tissue swelling Loose bodies Fluid levels Gas shadows Incidental bone pathology
Weight bearing AP	Normal reduction Coronal alignment Rotational alignment Distraction Patella height Normal bone outlines Patella fractures Bipartite patella Tibial plateau fractures Femoral condyle fractures Osteochondral fractures Avulsion Fractures Normal soft tissue outlines Fluid in the joint Swelling
Supine AP	Will not demonstrate loss of alignment under load
Routine Lateral	Normal reduction Sagittal alignment Rotational alignment Distraction Patella height Normal bone outlines Patella fractures Tibial plateau fractures Femoral condyle fractures (esp posterior) Osteochondral fractures Ligament avulsions Normal soft tissue outlines Fluid in the joint Swelling Extensor mechanism swelling
Horizontal Beam Lateral	Will not demonstrate loss of alignment and usually indicates the knee is too painful for the routine examination Fluid levels
Skyline view	Patella fractures Osteochondral fractures Patellofemoral ligament avulsions
Notch view	Osteochondritis dissecans Loose bodies Anterior cruciate avulsion
Oblique views	Subtle tibial plateau fractures