Editing Synovial fluid (section)

==Clinical significance==

===Collection===
Synovial fluid may be collected by syringe in a procedure termed [[arthrocentesis]], also known as joint aspiration.

===Classification===
Synovial fluid may be classified into normal, noninflammatory, inflammatory, septic, and hemorrhagic:
{| class="wikitable" border="1" style="border-collapse:collapse"
|+Classification of synovial fluid in an adult [[knee]] joint.
|- bgcolor="#cccccc"
|bgcolor="#ffffff"| || Normal || Non-inflammatory || Inflammatory || Septic || Bleeding
|-
|bgcolor="#cccccc"| Volume (ml) || <3.5   || >3.5             || >3.5         || >3.5   || >3.5
|-
|bgcolor="#cccccc"| [[Viscosity]]   || High   || High             || Low          || Mixed  || Low
|-
|bgcolor="#cccccc"| Clarity     || Clear  || Clear            || Cloudy       || Opaque || Mixed
|-
|bgcolor="#cccccc"| Color       || Colorless/straw || Straw/yellow || Yellow  || Mixed  || Red
|-
|bgcolor="#cccccc"| [[White blood cell|WBC]]/mm<sup>3</sup> || <200 || <2,000<ref name=agabegi2nd6-6/> || 5,000<ref name=agabegi2nd6-6/>-75,000 || >50,000<ref name=agabegi2nd6-6/> || Similar to blood level
|-
|bgcolor="#cccccc"| [[Polysegmented neutrophil|Polys]] (%)  || <25    || <25<ref name=agabegi2nd6-6/>              || 50<ref name=agabegi2nd6-6/>-70<ref name=agabegi2nd6-6>Table 6-6 in: {{cite book |author1=Elizabeth D Agabegi |author2=Agabegi, Steven S. |title=Step-Up to Medicine (Step-Up Series) |publisher=Lippincott Williams & Wilkins |location=Hagerstwon, MD |year=2008 |isbn=978-0-7817-7153-5 |url-access=registration |url=https://archive.org/details/stepuptomedicine0000agab }}</ref>          || >70<ref name=agabegi2nd6-6/>    || Similar to blood level
|-
|bgcolor="#cccccc"| [[Gram stain]] || None || None   || None    || + (S aureus & Streptococcus) - (Neisseria gonorrhoeae)|| None
|}
Glucose (mg/dl) concentration in synovial fluid is nearly equal to serum.
;Synovial fluid viscosity
''Normal'':
*Normal
*Traumatic arthritis
*Degenerative (Osteo) arthritis
* Pigmented villonodular synovitis
''Normal or decreased'':
*Systemic lupus erythematosus
''Decreased'':
*Rheumatic fever
*Rheumatoid arthritis
*Gout
*Pyogenic (Septic) arthritis
* Tubercular arthritis
* Less of lubrication in joints

===Pathology===
[[Image:Illu synovial joint.jpg|right|Synovial joint]]
Many synovial fluid types are associated with specific diagnoses:<ref name=fpnlupus>{{cite web
 |url=http://www.fpnotebook.com/Rheum/Lab/LpsAntcglnt.htm 
 |title=Lupus Anticoagulant 
 |publisher=Family Practice Notebook 
 |archive-url=https://web.archive.org/web/20130118110623/http://www.fpnotebook.com/Rheum/Lab/LpsAntcglnt.htm 
 |archive-date=18 January 2013 
 |url-status=live 
 |access-date=7 April 2013 
}}</ref><ref>[http://www.rheumatology.org/publications/primarycare/number6/hrh0033698.asp?aud=mem American College of Rheumatology]  {{webarchive |url=https://web.archive.org/web/20040905224401/http://www.rheumatology.org/publications/primarycare/number6/hrh0033698.asp?aud=mem |date=September 5, 2004 }}</ref>

{{columns-list|
* Noninflammatory (Group I)
** [[Osteoarthritis]], [[degenerative joint disease]]
** Trauma
** [[Rheumatic fever]]
** Chronic [[gout]] or [[pseudogout]]
** [[Scleroderma]]
** [[Polymyositis]]
** [[Systemic lupus erythematosus]]
** [[Erythema nodosum]]
** [[Neuropathic arthropathy]] (with possible hemorrhage)
** [[Sickle-cell disease]]
** [[Hemochromatosis]]
** [[Acromegaly]]
** [[Amyloidosis]]
* Inflammatory (Group II)
** [[Rheumatoid arthritis]]
** [[Reactive arthritis]]
** [[Psoriatic arthritis]]
** Acute rheumatic fever
** Acute gout or pseudogout
** Scleroderma
** Polymyositis
** Systemic lupus erythematosus
** [[Ankylosing spondylitis]]
** Inflammatory bowel disease arthritis
** [[Infection]] (viral, fungal, bacterial) including [[Lyme disease]]
** Acute [[crystal synovitis]] (gout)
* Septic (Group III)
** Pyogenic bacterial infection
** [[Septic arthritis]]
* Hemorrhagic
** Trauma
** [[Tumor]]s
** [[Hemophilia]]/[[coagulopathy]]
** [[Scurvy]]
** [[Ehlers-Danlos syndrome]]
** Neuropathic arthropathy
}}