Impaction Bone Grafting with Hydroxyapatite: Increased Femoral Component Stability in Experiments Using Sawbones

Background: Substantial bone loss and bone defects increase the amount of allografting required in hip revision surgery. Thus, the use of a synthetic material to limit the amount of allograft tissue required for impaction grafting is desirable. We evaluated the potential of hydroxyapatite (HA) mixtures to provide initial mechanical stability to a polished tapered femoral stem.

Material And Methods: We determined the initial stability of a polished tapered femoral stem after reconstructing a cavitary femoral bone defect by impaction bone grafting with cement in Sawbones composite femurs. Three types of graft material were tested for their ability to improve initial rotational stability. The graft materials investigated were pure allograft, a mixture of 50% allograft and 50% hydroxyapatite (HA), and pure HA.

Results: We found a statistically significant difference between the three groups as regards torsional micromotion and failure load.

Interpretation: Our findings suggest that reconstruction of femoral bone defects with pure HA or a mixture of allograft and HA provides adequate initial stability for femoral revision arthroplasty using impaction grafting.