Ldt. Topoleski et al., FLOW INTRUSION CHARACTERISTICS AND FRACTURE PROPERTIES OF TITANIUM-FIBER-REINFORCED BONE-CEMENT, Biomaterials, 19(17), 1998, pp. 1569-1577
Two clinically relevant considerations for a new bone cement are its f
racture properties and flow intrusion characteristics. We present data
for a titanium-fibre-reinforced poly(methyl methacrylate) (Ti-PMMA).
The fracture properties presented are a concise review of previously p
ublished material, while the flow intrusion observations are new. We p
erformed fracture toughness and fatigue fracture experiments. Two type
s of fatigue specimens were designed and tested. A 'smooth' specimen r
epresented the extreme case of minimum surface flaws. The lifetime of
a 'smooth' specimen incorporates fatigue crack initiation (FCI) and fa
tigue crack propagation (FCP). 'Notched' specimens were created by mac
hining a sharp notch into cylindrical specimens. The sharp notch effec
tively eliminated FCI from a random surface flaw and thus we made the
assumption that the lifetime of the notched specimen was a function of
FCP only. Fatigue testing was performed on rotating-bending fatigue m
achines until failure. Fibre addition resulted in a significant increa
se in fracture toughness over the control bone cement. Fibre addition
and the combination of fibre addition and centrifugation increased the
fatigue crack initiation and propagation resistance of the bone cemen
t. For the intrusion studies, eight femurs were obtained from four dog
s. The femurs were prepared following a procedure similar to that in h
uman hip replacement surgery. One of the pair of femurs from each dog
was filled with non-reinforced bone cement and the other was filled wi
th Ti-PMMA. A stainless-steel rod was inserted into the cement to simu
late the insertion of a prosthesis stem. The cemented bones were secti
oned and then stained with Alizarin Red S to distinguish the bone from
the PMMA or Ti-PMMA. Because of the irregular bone morphology, it was
not practical to quantify intrusion depth, but instead to make genera
l observations on the intrusion characteristics. The Ti fibres did not
generally flow into the small openings; however, fibre addition did n
ot hinder the bone cement's ability to penetrate into bone interstices
. (C) 1998 Elsevier Science Ltd. All rights reserved.