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Ovine model for critical-size tibial segmental defects.
Chris Christou1, Rema A Oliver2, Matthew H Pelletier2
1Surgical and Orthopaedic Research Laboratory, Prince of Wales Clinical School, University of New South Wales. Avoca St Randwick, Australia. c.christou@unsw.edu.au.
Comparative Medicine
|November 18, 2014
Summary
This study established a large animal model for tibial defects to test treatments for bone nonunions. The model effectively simulated nonunion, showing limited bone healing after 12 weeks.
Area of Science:
- Orthopedic surgery
- Biomaterials science
- Regenerative medicine
Background:
- Segmental tibial defects present significant clinical challenges, often leading to nonunions.
- Developing reliable large animal models is crucial for evaluating novel treatments for bone defects and trauma.
Purpose of the Study:
- To establish and validate a large animal model of a segmental tibial defect in sheep.
- To assess the feasibility of using this model for testing therapeutic strategies for bone healing.
Main Methods:
- A 5-cm mid-diaphyseal osteoperiosteal defect was created in the tibias of 12 aged ewes.
- Defects were stabilized with an intramedullary nail, and animals were evaluated at 12 weeks post-surgery.
- Assessment included radiography, microcomputed tomography (microCT), and histology.
Main Results:
- Radiography showed no hard tissue callus bridging the defect.
- MicroCT analysis revealed minimal bone formation (1.82 ± 0.94 cm³) within the 16.5 cm³ defect.
- Histology confirmed incomplete bridging with fibrous tissue, and clinical, radiographic, and histologic union was not achieved.
Conclusions:
- The established sheep model successfully created a nonunion segmental tibial defect.
- This model is suitable for investigating surgical techniques and adjuncts for treating nonunions resulting from significant bone loss.
