title: ERCC1 expression in aseptic loosening after total hip replacement.
abstract: Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The purpose of the current study was to evaluate the DNA damage repair capacity of macrophages in patients with aseptic hip loosening by determination of ERCC1. Moreover, we wanted to elucidate if the potency of the DNA-repair mechanisms correlates with the survival of joint implants. For this purpose we compared the immunohistochemical ERCC1 expression in capsules and interface membranes of patients with loosening of a hip replacement in the first 10 years after implantation with those in patients with late loosening. In analogy with ERCC1 studies on cancer in humans we calculated the semi-quantitative H-score by multiplying the staining intensity with the proportion score of positive stained macrophages. The level of ERCC1 reaction in the specimens taken from patients with early aseptic loosening (mean H-score 0.57) was clearly lower in comparison with those from patients undergoing exchange hip arthroplasty later than 10 years after surgery (mean H-score 2.24). We determined an H-score for ERCC1 expression of 1 as a cutoff point giving a sensitivity and specificity of 100% for identification of early aseptic loosening after less than 10 years. In summary, lower levels of ERCC1 were found in patients with early aseptic loosening compared to patients with aseptic loosening later than 10 years.
authors.affiliation: Department of Orthopaedics, University of Duisburg-Essen, Pattbergstrasse 1-3, 45239 Essen, Germany. stlandy@t-online.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Landgraeber
authors.forename: Marius
authors.initials: M
authors.lastname: von Knoch
authors.forename: Franz
authors.initials: F
authors.lastname: Löer
authors.forename: Alexander
authors.initials: A
authors.lastname: Wegner
authors.forename: Michael
authors.initials: M
authors.lastname: Tsokos
authors.forename: Kurt Werner
authors.initials: KW
authors.lastname: Schmid
authors.forename: Martin
authors.initials: M
authors.lastname: Totsch
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D001344:Autopsy; D002452:Cell Count; D004396:Coloring Agents; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D004720:Endonucleases / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D006621:Hip Joint / Q000166:cytology / Q000473:pathology; D006622:Hip Prosthesis; D006801:Humans; D007150:Immunohistochemistry; D017746:Joint Capsule / Q000166:cytology / Q000473:pathology; D008264:Macrophages / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D012372:ROC Curve; D016019:Survival Analysis; D016707:Tissue Fixation
chemical_list: D004396:Coloring Agents; D004268:DNA-Binding Proteins; C071447:ERCC1 protein, human; D004720:Endonucleases