Scapula pre-augmentation in sheep with polycaprolactone tricalcium phosphate scaffolds

Scapula free flaps are frequently used to reconstruct intraoral defects in the mandible and maxilla. However, limitations persist regarding the shape and volume of bone available for later implant placement. Prior research has shown that the scapula flap provides sufficient soft tissue but lacks predictable bony augmentation. This gap motivated the exploration of pre-augmentation techniques to improve bone quality and volume. No prior work had resolved how to effectively modify the scapula before flap harvesting. The need for a reliable scaffold material led to the use of polycaprolactone and tricalcium phosphate. These materials are known for their biocompatibility and osteoconductive properties. This study aimed to test whether pre-augmentation with a PCL-TCP scaffold could enhance the scapula's suitability for flap surgery. The focus was on evaluating scaffold integration and bone regeneration in a large animal model.

The goal was to assess the feasibility of pre-augmenting the scapula with a PCL-TCP scaffold in a sheep model. The specific problem addressed was the lack of sufficient bone volume and shape in the scapula for intraoral reconstruction. The motivation stemmed from the limitations of current flap techniques in providing adequate bone for implants. The study aimed to determine if scaffold placement could improve the scapula's structural properties. Researchers also wanted to evaluate scaffold degradation and new bone formation over time. The sheep model was chosen for its anatomical similarity to human bone structures. The experiment sought to provide a foundation for future clinical applications. The findings could guide the development of improved reconstructive strategies.

The study involved three adult sheep with scapular pre-augmentation using PCL-TCP scaffolds. The scaffolds were implanted as blocks at the scapula angle. Animals were monitored for six months to assess scaffold integration and bone formation. Cone-beam computed tomography scans were used to evaluate bone volume and scaffold degradation. Histomorphometric analysis was conducted to confirm the presence of new bone within the scaffold. No complications were observed in the augmented regions during the study period. The animals remained healthy throughout the experiment. The study design focused on structural and functional outcomes in a controlled animal model.

All three sheep tolerated the procedure well without complications in the augmented regions. The scaffolds remained firmly attached to the scapula and exhibited a bonelike consistency. Histomorphometric analysis confirmed the presence of new bone within the scaffold. Cone-beam computed tomography showed partial degradation of the scaffold material. Approximately half of the scaffold was replaced by vital bone after six months. The remaining scaffold showed signs of continued degradation. The results suggest that the PCL-TCP material supports bone regeneration in the scapula. The findings indicate that pre-augmentation with this scaffold is a viable approach in sheep.

The study demonstrated that PCL-TCP scaffolds can be successfully used to pre-augment the scapula in sheep. The scaffolds remained stable and supported new bone formation over six months. The authors propose that this method could improve the suitability of the scapula for intraoral reconstruction. The findings suggest that scaffold material is biocompatible and osteoconductive. No adverse effects were observed in the study animals. The results support the potential for further experiments on flap transplantation. The authors suggest that future work should explore the use of modified scapula flaps in intraoral defect sites. These conclusions are based on the observed stability and bone regeneration in the sheep model.