Clodronate reduces plate osteopenia in the rabbit

Area of Science:

• Orthopedic surgery
• Bone biology
• Pharmacology

Background:

• Rigid plate fixation in osteosynthesis can lead to significant bone loss and resorption under the implant.
• The osteopenic response under orthopedic plates is a known complication, affecting bone density and structural integrity.

Purpose of the Study:

• To investigate the effects of clodronate, a bisphosphonate, on bone changes associated with rigid tibial osteosynthesis in a rabbit model.
• To determine if clodronate can counteract bone resorption and maintain bone mass during the healing process after plate fixation.

Main Methods:

• Osteosynthesis using a four-hole AO/ASIF-DCP plate on the right tibia of 40 rabbits.
• Weekly subcutaneous administration of clodronate (50 mg/kg) with bone concentration analysis.
• Assessment of cortical bone area, porosity, medullary space expansion, and calcium content at 9 and 18 weeks.

Main Results:

• Plate fixation decreased compact cortical bone area by 17% at 9 weeks and 46% at 18 weeks, with increased porosity and medullary space.
• Clodronate treatment significantly reduced cortical porosity by approximately half compared to placebo.
• Clodronate increased bone calcium content and compact cortical bone area, with a minor effect on periosteal new bone.

Conclusions:

• Clodronate effectively reduces bone resorption and porosity associated with rigid tibial osteosynthesis.
• Bisphosphonate therapy appears safe and potentially beneficial in mitigating the osteopenic response under rigid orthopedic plates.
• Clodronate may be a viable adjunct therapy to preserve bone mass during fracture healing with rigid fixation.