title: Cobalt in periprosthetic soft tissue. Observations in 6 revision cases.
abstract: Cobalt (Co) was analyzed in sera obtained before surgery and in biopsies of periarticular soft tissue from 7 control patients undergoing primary total hip arthroplasty and from 6 Co-exposed patients who developed aseptic loosening of the femoral component after hip arthroplasty (CoCrMo alloy, greater than 59 percent Co, metal-on-plastic type). Serum-Co concentrations were not elevated in the Co-exposed patients compared with control patients or healthy adults. In 5 of the 6 Co-exposed patients, Co concentrations were greatly increased in periprosthetic tissue sections 0-1 mm from the synovial surface (median 2.4 [2.1-27] micrograms Co/g) compared with corresponding sections from the control patients (median 0.4 [0.1-0.6] microgram Co/g). Co concentrations diminished in tissue sections at successive distances of 2-3 and 4-5 mm from the synovial surfaces. In the Co-exposed patients, Co concentrations in sera and periprosthetic soft tissues were not correlated, indicating that serum Co concentration is not a reliable index of the Co burden in periprosthetic soft tissue.
authors.affiliation: Department of Orthopedics, University of Connecticut School of Medicine, Farmington 06032-1805.
authors.forename: C G
authors.initials: CG
authors.lastname: Lewis
authors.forename: R M
authors.initials: RM
authors.lastname: Belniak
authors.forename: S M
authors.initials: SM
authors.lastname: Hopfer
authors.forename: F W
authors.initials: FW
authors.lastname: Sunderman
mesh_terms: D000328:Adult; D000368:Aged; D002858:Chromium Alloys; D003035:Cobalt / Q000032:analysis* / Q000097:blood; D003238:Connective Tissue / Q000737:chemistry*; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D012086:Reoperation; D013054:Spectrophotometry, Atomic
chemical_list: D002858:Chromium Alloys; D003035:Cobalt