title: Fixation strength of taper connection at head-neck junction in retrieved carbon fiber-reinforced PEEK hip stems.
abstract: Carbon fiber-reinforced polyetheretherketone (CFR-PEEK) hip prostheses possess numerous advantages over metal prostheses; however, the security of the taper connection between the CFR-PEEK stem and the modular femoral head in vivo has not been verified. Therefore, we mechanically examined the taper connection of retrieved in vivo loaded CFR-PEEK stems in comparison with in vivo loaded titanium alloy stems. CFR-PEEK and titanium alloy femoral stems with a 12/14 taper trunnion were implanted in ovine hips. A 22-mm ceramic head was intraoperatively impacted to the stem. Retrieved specimens were obtained following weight-bearing conditions for up to 39 postoperative weeks and taper junction pull-off tests were conducted. Postoperative retrieved CFR-PEEK stem pull-off strength was significantly greater than that at time zero. Postoperative retrieved CFR-PEEK stem pull-off strength was also significantly higher than that of postoperative retrieved titanium alloy stem. Microscopic findings of the taper surface revealed no obvious damage in the retrieved CFR-PEEK stems, whereas fretting and corrosion were observed in the retrieved titanium alloy stems. The present findings suggest that the taper connection between the ceramic head and the 12/14 CFR-PEEK stem trunnion is more secure than that between the ceramic head and the titanium alloy trunnion.
authors.affiliation: Department of Orthopaedic Surgery, Osaka National Hospital, 2-1-14 Hoenzaka, Chuo-ku, Osaka, 5400006, Japan, ichiro-n@umin.net.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Nakahara
authors.forename: Masaki
authors.initials: M
authors.lastname: Takao
authors.forename: Shunichi
authors.initials: S
authors.lastname: Bandoh
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Sugano
mesh_terms: D000818:Animals; D019644:Arthroplasty, Replacement, Hip; D001577:Benzophenones; D002516:Ceramics; D006622:Hip Prosthesis; D007659:Ketones; D008422:Materials Testing; D011092:Polyethylene Glycols; D011108:Polymers; D011474:Prosthesis Design; D012756:Sheep; D014025:Titanium
chemical_list: D001577:Benzophenones; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols; D014025:Titanium