title: Early failure of hydroxyapatite-coating in total knee arthroplasty. A case report.
abstract: We observed early loosening of a hydroxyapatite-coated tibial component in a total knee arthroplasty in a randomized study comparing HA-coating with cement fixation. Symptoms of loosening started 8 weeks after surgery. Roentgen stereophotogrammetric analysis revealed stability during the initial 6 weeks followed by a pronounced subsidence up to 6 months after surgery when revision was done. At revision, the HA-coating was found to have separated from the medial part of the tibial component. The synovium was abundant with macrophages and multinucleated giant cells containing HA-crystals. Overloading of the prosthesis and suboptimal quality of the HA-coating was believed to have caused the loosening process.
authors.affiliation: Department of Orthopedics, University Hospital, Umeå, Sweden.
authors.forename: K G
authors.initials: KG
authors.lastname: Nilsson
authors.forename: S
authors.initials: S
authors.lastname: Cajander
authors.forename: J
authors.initials: J
authors.lastname: Kärrholm
mesh_terms: D000368:Aged; D017886:Durapatite; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D013583:Synovial Membrane / Q000473:pathology
chemical_list: D017886:Durapatite