The effects of acetabular cup temperature and duration of cement pressurization on cement porosity in a canine total hip replacement model.
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.
Shields
S L
SL
JD Wheat Veterinary Orthopedic Research Laboratory, School of Veterinary Medicine, University of California, Davis, CA, USA.
Schulz
K S
KS
Hagan
C E
CE
Kass
P
P
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
D001843:Bone Cements