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Effects of substitute coated with hyaluronic acid or poly‐lactic acid on implant fixation: Experimental study in ovariectomized and glucocorticoid‐treated sheep
Author(s) -
Andreasen Christina M.,
Ding Ming,
Andersen Thomas L.,
Overgaard Søren
Publication year - 2018
Publication title -
journal of tissue engineering and regenerative medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.835
H-Index - 72
eISSN - 1932-7005
pISSN - 1932-6254
DOI - 10.1002/term.2447
Subject(s) - ovariectomized rat , implant , chemistry , biomedical engineering , hyaluronic acid , condyle , fixation (population genetics) , femur , osseointegration , surgery , anatomy , biochemistry , medicine , hormone , gene
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.