Photodynamic Therapy Treatment to Enhance Fracture Healing.

摘要

Long bone fractures resulting from high impact trauma can result in delayed healing. In spite of currently available treatments to enhance bone healing, these fractures can take up to a year to fully heal. Photodynamic therapy (PDT) is a minimally invasive local treatment currently used to treat cancer and skin diseases. Surprisingly, recent findings from studying the effect of PDT on vertebrae when treating spinal metastases have shown that PDT improved the strength and stiffness of the vertebrae. A critical size defect fracture of the femur was generated in 20 adult female Sprague-Dawley rats. PDT treatment was applied either 1d or 7d after fracture generation. CT analyses of the non-infection rats showed a bone mineral density (BMD) (gHA/cm2) slightly higher in the PDT treated groups (1d PDT: 0.86 0.02; 7d PDT: 0.85 0.08) compared to controls (0.79 0.09), however the differences were not statistically significant. A smaller gap and more bone formation in the PDT treated groups could only be seen when the fracture gap at surgery was 6 mm. In these 6 animals the 1dPDT rats had the most bone formation (4.18 1.68 mm) compared to control (2.26 0.7 mm) and 7d PDT (3.80 0.98 mm). Further studies with longer time-points and a defect 6 mm are necessary to validate these observations.