ARUP's Laboratory Test Directory

Cobalt, Joint Fluid : 2005549

Mnemonic: CO F

Ordering Recommendation: Preferred test for evaluating metal ion release from metal-on-metal joint arthroplasty is Cobalt, Serum (ARUP test code 0025037).
Methodology: Quantitative Inductively Coupled Plasma-Mass Spectrometry
Performed: Tue, Thu, Sat
Reported: 1-4 days
Specimen Required: Patient Prep: High concentrations of iodine may interfere with elemental testing. Patients should abstain from iodine-containing medications or contrast agents for at least 1 month prior to specimen collection for elemental testing.

Collect: Joint fluid. The use of betadine-like topical antiseptics should be avoided during specimen collection.

Specimen Preparation: Transfer 1 mL joint fluid to an ARUP Trace Element-Free Transport Tube (ARUP supply #43116). Available online through eSupply using ARUP Connect™ or contact ARUP Client Services at (800) 522-2787. (Min: 0.5 mL)

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Separator tubes and gels. Fluid collected after administration of a gadolinium (Gd) containing contrast media (may occur with MRI studies).

Stability (collection to initiation of testing): Ambient: 1 week; Refrigerated: 2 weeks; Frozen: 1 year

Interpretive Data: Serum is the preferred specimen for evaluating metal ion release from metal-on-metal joint arthroplasty. Metal ion testing of joint fluid may be complementary to serum testing, but reference intervals for joint fluid are not established. Concentrations of cobalt may exceed 100 ug/L in fluid collected from an affected joint.
Note: Contamination from noncertified trace element-free tubes may cause elevated results.
CPT Code(s): 83018
Cross References: Hip Replacement (Cobalt, Joint Fluid), Joint, Arthroplasty (Cobalt, Joint Fluid), Knee Replacement (Cobalt, Joint Fluid), Metal Ion Testing (Cobalt, Joint Fluid), Synovial Fluid (Cobalt, Joint Fluid)
 
 

 

 

 
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