Local alendronic acid elution increases net periimplant bone formation: a micro-CT analysis

Area of Science:

• Orthopedic research
• Biomaterials science
• Bone biology

Background:

• Cementless orthopedic implant fixation is often suboptimal, especially in revision surgery, trauma, and tumor reconstruction.
• Improved implant fixation can enhance the reliability and longevity of reconstructive procedures.

Purpose of the Study:

• To evaluate the impact of local alendronic acid elution on bone formation around porous titanium implants.
• To assess the dose-dependent effects of alendronic acid on periimplant bone integration in an animal model.

Main Methods:

• Porous titanium implants were coated with 0.2 mg or 1.0 mg of alendronic acid.
• Implants were surgically placed in the femora of 10 dogs.
• Periimplant bone volume was quantified using micro-computed tomography (micro-CT) at 12 weeks.
• Histology and backscattered scanning electron microscopy were used for detailed analysis.

Main Results:

• Alendronic acid significantly increased periimplant bone volume at both 0.2 mg (+52%) and 1.0 mg (+152%) doses compared to controls.
• The 1.0 mg dose showed a 2.9-fold greater increase in bone formation than the 0.2 mg dose.
• Micro-CT findings strongly correlated with histological and SEM analyses (R=0.965).

Conclusions:

• Local elution of alendronic acid promotes a dose-dependent increase in periimplant bone formation.
• This approach holds potential for improving biologic fixation of porous reconstructive orthopedic implants.