Blood cytokine pattern and clinical outcome in knee arthroplasty patients: comparative analysis 5 years after standard versus “hypoallergenic” surface coated prosthesis implantation

Background and purpose — Metal sensitivity might provoke complications after arthroplasty. Correspondingly, coated “hypoallergenic” implants are of interest but long-term follow-up data are missing. Thus, we assessed immunological and clinical parameters in such patients.Patients and methods — 5 years’ follow-up data were obtained from 3 centers, which used either a standard total knee replacement (TKR) or the identical implant with multilayer surface zirconium nitride based coating. Of the 196 patients (mean age 68 years (44–84), 110 females) 97 had arthroplasty with a coated surface, and 99 were treated by a standard TKR of the same type. Investigations were Knee Society Score (KSS), Knee injury and Osteoarthritis Outcome Score (KOOS), radiographic analysis, and cytokine measurement in peripheral blood. Pro- and anti-inflammatory cytokines were evaluated by cytometric beads assay and RT-PCR.Results — Survival rate (Kaplan–Meier) was 98% for coated and 97% for uncoated implants after 5 years. Mechanical ...