title: The effects of acetabular cup temperature and duration of cement pressurization on cement porosity in a canine total hip replacement model.
abstract: OBJECTIVE
  To determine the effect of acetabular cup temperature and duration of cement pressurization on porosity of the acetabular cement mantel.
  
  
  METHODS
  In vitro study.
  
  
  METHODS
  Twenty-four polyurethane foam blocks prepared for acetabular prosthetic implantation were implanted with polyethylene acetabular cups using four combinations and variations of temperature and pressure: (1) high temperature/short-term pressurization; (2) high temperature/long-term pressurization; (3) low temperature/long-term pressurization; and (4) low temperature short-term pressurization. Five 1-mm-thick slices were taken from the center of each block using a tissue processing system. The slices were scanned into a personal computer using a photo slide scanner. Imaging software was used to determine cement surface area and size, number, and distribution of pores. The quality of the cement-implant interface was subjectively evaluated. Statistical analysis of relative cement porosity was performed by a Kruskal-Wallis analysis of variance comparing the four groups individually and combining the short-term pressurization groups versus the long-term pressurization groups.
  
  
  RESULTS
  There were no significant differences in cement porosity between the four test groups (P =.11). There were no significant differences in porosity between the combined groups (P =.48).
  
  
  CONCLUSIONS
  There is no benefit in prewarming acetabular cups before implantation. There are no deleterious effects of short-term pressurization of the cement during implantation.
authors.affiliation: JD Wheat Veterinary Orthopedic Research Laboratory, School of Veterinary Medicine, University of California, Davis, CA, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Shields
authors.forename: K S
authors.initials: KS
authors.lastname: Schulz
authors.forename: C E
authors.initials: CE
authors.lastname: Hagan
authors.forename: P
authors.initials: P
authors.lastname: Kass
mesh_terms: D000077:Acetabulum; D000818:Animals; D019644:Arthroplasty, Replacement, Hip / Q000662:veterinary; D001696:Biomechanical Phenomena; D001843:Bone Cements; D002484:Cementation / Q000295:instrumentation*; D004285:Dogs / Q000601:surgery*; D006622:Hip Prosthesis / Q000662:veterinary*; D023421:Models, Animal; D013696:Temperature
chemical_list: D001843:Bone Cements