TY - JOUR

T1 - Effects of substitute coated with hyaluronic acid or poly-lactic acid on implant fixation. Experimental study in ovariectomized and glucocorticoid treated sheep

AU - Andreasen, Christina M

AU - Ding, Ming

AU - Andersen, Thomas L

AU - Overgaard, Søren

N1 - Copyright © 2017 John Wiley & Sons, Ltd.

PY - 2018/2

Y1 - 2018/2

N2 - Investigated in healthy animal models, hyaluronic acid (HyA) and poly- D,L-lactic acid (PDLLA) demonstrate osteoconductive properties when coated onto hydroxyapatite (HA) and β-tricalcium phosphate (βTCP) scaffolds. In this study, we examined the efficacy of HA/βTCP granules coated with HyA or PDLLA on implant fixation when applied as graft materials in 2-mm size defects created in the femur condyles of ovariectomized (OVX) glucocorticoid-treated (GC) sheep. Titanium alloys were inserted into the femur condyles of OVX and GC-treated sheep, and the concentric gaps were filled with either allograft obtained from a healthy donor sheep (control), pure HA/βTCP, HA/βTCP-HyA or HA/βTCP-PDLLA. After 12 weeks, the bone formation adjacent to the implant surface was evaluated by histology and histomorphometry, while the implant fixation was measured by a push-out test. The investigation showed a bone formation in the HA/βTCP-HyA and HA/βTCP-PDLLA groups not significantly different from allograft (p > 0.05), whereas the HA/βTCP group revealed a significantly reduced formation of bone compared with allograft (p < 0.05). Bone–implant contact (BIC) and mechanical properties were similar comparing HA/βTCP-HyA and HA/βTCP-PDLLA with allograft (p > 0.05). This study demonstrated that bone substitutes infiltrated with PDLLA and HyA possess osteoconductive properties comparable to allograft when tested in sheep with an OVX and GC-induced bone loss. With no significant difference in implant fixation and bone formation, HyA and PDDLA are indeed considered valuable as new coating materials for composite ceramics when tested in a sheep model – even in bones of a compromised quality.

AB - Investigated in healthy animal models, hyaluronic acid (HyA) and poly- D,L-lactic acid (PDLLA) demonstrate osteoconductive properties when coated onto hydroxyapatite (HA) and β-tricalcium phosphate (βTCP) scaffolds. In this study, we examined the efficacy of HA/βTCP granules coated with HyA or PDLLA on implant fixation when applied as graft materials in 2-mm size defects created in the femur condyles of ovariectomized (OVX) glucocorticoid-treated (GC) sheep. Titanium alloys were inserted into the femur condyles of OVX and GC-treated sheep, and the concentric gaps were filled with either allograft obtained from a healthy donor sheep (control), pure HA/βTCP, HA/βTCP-HyA or HA/βTCP-PDLLA. After 12 weeks, the bone formation adjacent to the implant surface was evaluated by histology and histomorphometry, while the implant fixation was measured by a push-out test. The investigation showed a bone formation in the HA/βTCP-HyA and HA/βTCP-PDLLA groups not significantly different from allograft (p > 0.05), whereas the HA/βTCP group revealed a significantly reduced formation of bone compared with allograft (p < 0.05). Bone–implant contact (BIC) and mechanical properties were similar comparing HA/βTCP-HyA and HA/βTCP-PDLLA with allograft (p > 0.05). This study demonstrated that bone substitutes infiltrated with PDLLA and HyA possess osteoconductive properties comparable to allograft when tested in sheep with an OVX and GC-induced bone loss. With no significant difference in implant fixation and bone formation, HyA and PDDLA are indeed considered valuable as new coating materials for composite ceramics when tested in a sheep model – even in bones of a compromised quality.

U2 - 10.1002/term.2447

DO - 10.1002/term.2447

M3 - Journal article

C2 - 28485126

VL - 12

SP - e1122-e1130

JO - Journal of Tissue Engineering and Regenerative Medicine

JF - Journal of Tissue Engineering and Regenerative Medicine

SN - 1932-6254

IS - 2

ER -