Functional osseointegration of hydroxyapatite-coated implants in a weight-bearing canine model.

Abstract That hydroxyapatite (HA) can form a strong chemical bond with bone has been confirmed by several precedent workers using unloaded implants. The relation-ship between the histomorphometric measurements of the interface of the cementless femoral stems with and without HA coating and their mechanical properties in a weight-bearing canine model was evaluated in this study. Seven HA-coated and seven uncoated titanium (Ti6Al4V) hemiarthroplasties were implanted in the right hip of 14 dogs for a 5-month period. The specimens were taken to conduct mechanical testing andmorphometric measuring. The average interface shear strength of 2.13 MPa for the HA-coated specimens was significantly higher than 0.93 MPa for the uncoated specimens ( P r =.81)