title: Improvement of the long-term adhesive strength between bone cement and bone in cemented cup arthroplasty: ex-vivo study.
abstract: BACKGROUND
  One of the main causes of cup loosening in cemented total hip replacement is the lack of a hydrolysis stable compound between the hydrophobic bone cement and the hydrophilic acetabular bone stock. Thus, the long-term adhesive strength between bone and bone cement is decreased resulting in premature aseptic loosening. Accordingly, an amphiphilic bonding system was developed to prevent hydrolytic debonding in the interface bone-to-bone cement.
  
  
  METHODS
  Polyethylene cups were cemented in cadaver sheep hips. The hips were prepared with (n = 10) a multilayer bonding system as well as with an improved monolayer bonding system with (n = 10) and without (n = 10) UV-light hardening. The hips were dynamically loaded (10(6) cycles; 3 Hz; upper/lower load 1,500/200 N) and afterwards turned out with a defined strength to determine the interface compound strength. Dynamically loaded cemented cups without using the bonding system (n = 10) function as a control group.
  
  
  RESULTS
  The interface adhesive strength improved significantly by a factor of 1.9 (using the multilayer bonding system) compared to the unconditioned ones (P < or = 0.05); for the monolayer bonding system without (with) UV-light hardening the compound strength was 11.9-fold (> or =22.2-fold) higher (P < or = 0.001).
  
  
  CONCLUSIONS
  The bonding system significantly improves the adhesive strength between bone and bone cement in cemented cup arthroplasty.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany. Torsten.Mumme@GMX.de
authors.forename: T
authors.initials: T
authors.lastname: Mumme
authors.forename: S
authors.initials: S
authors.lastname: Gravius
authors.forename: S
authors.initials: S
authors.lastname: Andereya
authors.forename: R
authors.initials: R
authors.lastname: Marx
authors.forename: D C
authors.initials: DC
authors.lastname: Wirtz
authors.forename: R
authors.initials: R
authors.lastname: Müller-Rath
mesh_terms: D000268:Adhesiveness; D000818:Animals; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D001843:Bone Cements; D066298:In Vitro Techniques; D020959:Polyethylene; D011474:Prosthesis Design
chemical_list: D001843:Bone Cements; D020959:Polyethylene