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Test ID COSY Cobalt, Synovial Fluid

Ordering Guidance

This test should only be used in individuals with metallic prosthetic implants. The significance of cobalt concentrations in synovial fluid in patients without implants is unknown.

Specimen Required

Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for at least 96 hours

Container/Tube: Royal blue top (metal-free EDTA)

Specimen Volume: 1 mL

Collection Instructions: See Metals Analysis Specimen Collection and Transport for complete instructions.

Additional Information: Cobalt is present in the black rubber plunger seals found in most disposable syringes. As a result, synovial fluid should not be collected in these devices as contamination may occur.

Useful For

Monitoring metallic prosthetic implant wear and local tissue destruction in failed hip arthroplasty constructs


This test is not useful for assessment of nutritional status or potential cobalt toxicity.

Method Name

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Reporting Name

Cobalt, Synovial Fl

Specimen Type

Synovial Fluid

Specimen Minimum Volume

0.4 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Synovial Fluid Refrigerated (preferred) 90 days
  Ambient  90 days
  Frozen  90 days

Reference Values

0-17 years: Not established

≥18 years: <19.8 ng/mL

Day(s) Performed


Report Available

2 to 8 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
COSY Cobalt, Synovial Fl 23842-8


Result ID Test Result Name Result LOINC Value
606352 Cobalt, Synovial Fl 23842-8