Effects of substitute coated with hyaluronic acid or poly‐lactic acid on implant fixation: Experimental study in ovariectomized and glucocorticoid‐treated sheep |
| |
| Authors: | Christina M Andreasen Ming Ding Thomas L Andersen Søren Overgaard |
| |
| Affiliation: | 1. Orthopaedic Research Laboratory, Department of Orthopaedic Surgery and Traumatology O, Odense University Hospital, Department of Clinical Research, University of Southern Denmark, Odense, Denmark;2. Department of Clinical Cell Biology (KCB), Vejle Hospital – Lillebaelt Hospital, Department of Regional Health Research, University of Southern Denmark, Vejle, Denmark |
| |
| Abstract: | 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. |
| |
| Keywords: | bone substitute coating material glucocorticoid‐induced osteoporosis histomorphometry implant fixation sheep model |
|
|
