The effect of osteopenia on the osteointegration of different biomaterials: histomorphometric study in rats.
The osteointegration of Hydroxyapatite (HA), Titanium (Ti-6Al-4V: Ti), Zirconia (ZrO2), Alumina (Al2O3) and 2 biological glasses (AP40 and RKKP) was comparatively investigated in normal and osteopenic rats by means of histomorphometry. Thirty-six Sprague Dawley female rats were left intact (Group C) while 36 were ovariectomized (Group OVX). Group C and OVX were further divided into 6 subgroups. After 16 weeks all animals were submitted to the femoral implant of nails made of the above-mentioned materials. Eight weeks after implantation the animals were euthanized, the femurs were harvested for histomorphometric analysis. The data showed that: (1) all the tested materials were biocompatible in vitro; (2) no significant differences existed in Affinity Index (AI) of Group C; and (3) results from paired comparison applied to the AI showed significant differences among the Groups C and OVX. The AI did not significantly change among intact groups, while it significantly decreased when some materials were implanted in OVX subgroups (AP40, ZrO2 and Ti-6Al-4V: p < 0.0005, p < 0.05 and p < 0.01). It is confirmed that bone mineral density is a strong predictor of the osteointegration of an orthopedic implant and that the use of pathological animal models is necessary to completely characterize biomaterials.
Fini
M
M
Experimental Surgery Department and Chair of Surgical Pathophysiology, University of Bologna, Research Institute Codivilla-Putti, Rizzoli Orthopedic Institute (I.O.R.), Via Di Barbiano 1/10, 40136 Bologna, Italy.
Giavaresi
G
G
Aldini
N N
NN
Torricelli
P
P
Morrone
G
G
Guzzardella
G A
GA
Giardino
R
R
Krajewski
A
A
Ravaglioli
A
A
Belmonte
M M
MM
Benedittis
A D
AD
Biagini
G
G