Skip to content

Markers of knee joint inflammation (e.g., synovial fluid analysis for inflammatory markers)

Published: August 9, 2026Updated: August 16, 2026

This test evaluates substances in your knee joint fluid that may indicate inflammation, infection, or other joint issues.

Quick summary

["It helps diagnose or monitor conditions affecting your knee, such as arthritis or infections."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
24802-1
Short code
MR Knee
Synonyms
MR Knee
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
mr
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

This test typically includes measuring levels of inflammatory markers (e.g., white blood cell count, cytokines) and other analytes in synovial fluid. These markers help identify the cause of knee pain or swelling, such as arthritis, gout, or septic arthritis.

Common Conditions Monitored

Inflammatory conditions like rheumatoid arthritis, osteoarthritis, or gout may show elevated levels of certain markers in knee fluid. Infections (e.g., septic arthritis) may reveal high white blood cell counts or bacterial markers.

Sample Collection and Preparation

A small amount of fluid is collected from your knee joint using a needle. This fluid is then sent to the lab for analysis. The test may require a sterile procedure to prevent contamination.

What to Expect Before the Test

You may experience mild discomfort during fluid collection, but numbing medication can be used. Avoid aspirin or anti-inflammatory medications for a few days before the test, as they may affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Why might my doctor order this test?
Your doctor may recommend this test if you have persistent knee pain, swelling, or redness that doesn’t improve with treatment. It helps determine whether inflammation, infection, or other conditions are causing your symptoms.
How long will I need to wait for results?
Results are usually available within 1–3 business days, depending on lab processing times. Your doctor will discuss the findings with you during your follow-up visit.
Can I eat or drink before this test?
No special preparation is needed for this test, but avoid heavy meals or fluids immediately before collection to minimize discomfort. Follow any specific instructions your doctor provides.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy