title: Effect of a prostaglandin EP4 receptor agonist on early fixation of hydroxyapatite/titanium composite- and titanium-coated rough-surfaced implants in ovariectomized rats.
abstract: The agonist of the prostaglandin EP4 receptor can increase bone density in osteoporosis. Using ovariectomized (OVX) and sham-operated (SO) rats, the effects of the EP4 receptor agonist, ONO-4819, and hydroxyapatite (HA) on implant-bone fixation in implants with a rough surface were investigated. Female Wistar rats (12 weeks old) were divided into either SO or bilateral OVX groups. Twenty four weeks later, either hydroxyapatite/titanium (HA/Ti) composite-coated or Ti-coated implants were implanted into the femora, and the animals were treated with either ONO-4819 or saline for 4 weeks. The fixation strength of the HA/Ti-coated implants was higher than that of the Ti-coated implants in the saline-treated OVX rats. In the OVX rats, ONO-4819 enhanced fixation of the rough Ti-coated implants to levels similar to that of HA/Ti-coated implants. These data suggest that a combination of treatment with an EP4 receptor agonist and a rough-surfaced implant might be useful in increasing the early fixation of cement-less arthroplasty, particularly in elderly patients with osteoporosis.
authors.affiliation: Department of Orthopaedic Surgery, Orthpaedic Research Laboratory, Fukuoka Wajiro Hospital, Higashi-ku, Fukuoka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.forename: A
authors.initials: A
authors.lastname: Fotovati
authors.forename: S
authors.initials: S
authors.lastname: Abu Ali
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
authors.forename: M
authors.initials: M
authors.lastname: Inagaki
authors.forename: M
authors.initials: M
authors.lastname: Naito