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



Mr Gavin Holt :: CotswoldClinics.com :: Print this frame