Initial study for chronic knee problem is X-ray
AP/LAT. Grade (X)
In AP view - Patella is centrally located.
Lateral view - The quadriceps and patella tendons
are best seen.
Axial view – This is mandatory to show
patellofemoral joint. Grade (X)
A. In Patella dislocation
X ray may show subtle osteochondral fragment in
the patella.
B. In Osgood schalatter,s disease –
X ray may show fragmented tibial tubercle
This can be confirmed by US in doubtful cases.
Patella tendinosis -
This can be assessed by US. Grade (Y)
D. In chondromalacia patellae -
MRI better assess the articular cartilage.
Grade(Y)
E. Nonlocalized knee pain with normal X-ray or
with evidence of effusion
Next exam should be MRI as it provides more
specific information. Apart from joint effusion, It
detects communicating synovial cysts,
proliferative changes of synovial membrane,
osteophytes, bone marrow edema, fractures and
any other lesion. Grade (Y)
F. When X-ray shows changes of OA
• Weight bearing PA X ray standing view better
assess the cartilage loss,
Standing X ray with knee flexed shows medial
and lateral joint compartment cartilaginous loss
than supine X-ray.
• In advanced OA joint narrowing in plain X ray
indicates cartilage loss. Then no further work
up is needed.
• In early stages of OA plain X ray may not be
sensitive.
When x ray is normal but clinically suspecting
OA, MRI is done for assessment of cartilage as
it is important in the management.