Osteoarthritis (OA) is cartilage failure resulting in joint
pain and loss of joint functions. Knee OA is the OA of knee that
mechanical forces have major effect on initiation and progression
of it. Knee OA is the most common disease of knee especially in
the middle to old ages. The most common findings in the history
and physical examination of the patients with knee OA are
mechanical knee pain, gelling knee pain, crepitus on knee motion,
bony tenderness and bony enlargement in the joint line. During the
flare up of Osteoarthritis, knee can show swelling due to joint
effusion called “Hydrarthrosis” that is a mechanical type of
synovial fluid.
It is usually a cold effusion and sometimes it is
accompanied by warmth and mild synovitis or synovial thickening,
but moderate to significant knee synovitis and hot or red knee
cannot be seen during its OA flare up.
Factors that place the people at higher risk for knee OA are: middle
to old ages, obesity, frequent knee bending activity, climbing the
stairs frequently, squatting or deep knee bending for prolonged time
and lifting or moving heavy objects frequently.
There is not any significant positive finding in
biochemistry tests of the patients with knee OA. Plain radiography
has low sensitivity regarding knee OA during the early phase of the
disease but the MRI of knee is the most sensitive imaging during
this early phase. Among the X-Ray findings, osteophyte has the
most specificity for OA and the presence of cartilage defects and
Bone Marrow Edema (BME) concomitantly are compatible MRI
findings for OA.
The diagnosis of knee OA can be usually made by
clinical/imaging judgment of an expert physician. There are three
ACR classification criteria for knee OA that are useful for research
purposes but they are not valuable for early diagnosis of knee OA.
By this letter, the author wants to deliver a new criteria called
“2016 ACR revised criteria for early diagnosis of knee OA”.
Keywords: Knee Osteoarthritis; Mechanical Knee Pain;
Osteophyte; Revised Criteria for Early Diagnosis