Intramedullary cement osteosynthesis (IMCO): a pilot study in sheep

Area of Science:

• Orthopedics
• Biomaterials Science
• Regenerative Medicine

Background:

• Bone substitutes and cements are historically used with fracture fixation, not as primary fixation.
• Intramedullary bone cement offers potential for simultaneous fixation and bone enhancement.
• This study investigates intramedullary cement as a primary fixation method.

Purpose of the Study:

• To evaluate the feasibility and safety of intramedullary calcium phosphate cement (CPC) injection for bone augmentation.
• To assess the bone augmentative effects and biomechanical improvements in a sheep tibia model.
• To explore a novel approach for fracture fixation, particularly in compromised bone quality.

Main Methods:

• Two sheep underwent tibial transverse osteotomies with external skeletal fixation.
• Medullary canals were prepared and injected with calcium phosphate cement (CPC).
• Outcomes were assessed via radiographs, morphology, histology, and biomechanical testing.

Main Results:

• Healing was uncomplicated until external fixator failure caused one fracture recurrence.
• Significant cortical thickening observed: 56% at fracture site, 48% in diaphyses.
• Bending strength increased by 264% at the fracture site and 148% in adjacent diaphyses.

Conclusions:

• Intramedullary calcium phosphate cement (IMCO) using CPC in sheep tibias is safe and biocompatible.
• The method shows potential for sustained bone augmentation and osteopromotion.
• This technique may offer advantages for bones with compromised quality, like osteoporosis.