54.
Local treatment with zoledronate does not inhibit new bone formation
Mette Sørensen, Jørgen Baas, Jeppe Barckman, Joan E. Bechtold, Kjeld
Søballe
Orthopaedic Research Laboratory, Department of Orthopaedic Surgery Aarhus
University Hospital; Orthopaedic Research Laboratory, Department of
Orthopaedic Surgery, Aarhus University Hospital; Orthopaedic Research
Laboratory, Department of Orthopaedic Surgery, Aarhus University Hospital;
Minneapolis Medical Research Foundations, University of Minnesota;
Orthopaedic Research Laboratory, Department of Orthopaedic Surgery,
Aarhus University Hospital
Background:
Bone allograft is often used to restore bone stock in revision
surgery. The allograft serves as a scaffold for new bone formation but is
subject to resorption, which can jeopardize initial fixation. Local treatment
with bisphosphonate has been used to reduce graft resorption, but the treatment
may block new bone formation.
Purpose / Aim of Study:
In this study we investigated the effect of low-dose
zoledronate treatment on bone allograft and its effect on new bone formation
in an experimental revision implant setting.
Materials and Methods:
We conducted a paired study with 12 canines. 24
pistoning micromotion implants were inserted bilaterally into the knees
according to our revision protocol, allowing formation of a standardized
revision cavity. After 8 weeks implants were revised. This left a 1.1-mm gap
around the non-motioning, plasma- sprayed titanium revision-implant, which
was impacted with morselized allograft. On the intervention side the allograft
was soaked in zoledronate (0.005mg/ml) for 3 minutes and rinsed. Control
allograft was soaked in saline following the same procedure. Observation after
revision was four weeks. Data was evaluated by paired t-test. P- values <0.05
were considered statistically significant.
Findings / Results:
Histomorphometrical analysis showed a 3- fold increase in
bone allograft volume (p<0.001) compared to the control side. Furthermore,
the zoledronate treatment did not impair new bone formation (p=0.311).
Conclusions:
We found increased preservation of bone allograft on the
intervention side without impairment of new bone formation. In the clinical
setting, allograft impregnation with low-dose zoledronate may be a practical
method of retaining bone allograft without impairing new bone formation. We
did not examine long-term effects, and protocolled trials are needed before
implementing this as a standard regimen.
