Have you watched Part-1 of knee pain diagnosis. If not then please do it by clicking here.
Let us say you have so much arthritis knee pain and your doctor asked you to take plain x-ray of your knees.
What he would be looking for in knee xray?
Plain x-ray of knee helps doctor evaluate knee arthritis , fractures or other knee related problems.
X-ray will help doctor corner the most common cause of knee pain.
Above picture shows a direct comparison between a normal knee and an arthritic knee.
Doctor would compare both x-rays to see following difference:
Normal Joint Space- the joint space between articular surfaces is normal.
Normal gap of 6-7 mm.
NO osteophytes seen- no bone spurs on margins of articular surfaces.
Bone on Bone - the joint space is minimal or none or in extreme cases bone on bone.
No gap seen or reduced.
Osteophytes seen- Osteophytes are present on articular surfaces which are called bone spurs.
Doctor would also see alignment of the knee joint or knee bones to see which compartment of the knee joint is affected.
for people with knock knees the medial compartment of knee joint is having no knee joint space.
Thus doctor could decide about partial knee replacement surgery.
X-ray also helps in differential diagnosis as well.
X-rays have all importance in diagnosing arthritis and fractures and else but they have limited role in diagnosing soft tissue injuries like ACL injury, torn cartilage in knee etc.
In most cases doctor would ask you to take a X-ray in standing position.
Different positional x-rays also needs to be done like sunrise x-ray where under surface of patella had arthritic changes.
For patients with bow legs the lateral compartment of knee joint would be damaged and having no joint space or diminished space.
Please if you have a real life experience or you liked what I have shared with you here please comment in comment section so that other people who read this can get benefited.