**Acknowledgements**

film. The problem with the two patients in whom the therapy failed was the poor incorporation of the graft in the distal tibia, where bone healing is compromised through many factors [51]. One of the patients had a deteriorating psychiatric disorder and could not follow instructions later in the study, and one had a poor bone situation arising from previous treatments. The other seven patients with successful outcomes achieved a satisfactory clinical improvement

A bacterial infection did not reoccur in cases where an infection was previously treated. Our treatment has concluded prolonged ongoing hospitalizations and immobilizations for some patients who previously underwent numerous operations and rehabilitations. Only one

As bioengineering techniques improve and become more clinically applicable, so does the field of application expand. In our work we have shown one of the methods to be useful in treating

Further application of platelet rich plasma as a source of growth factors can be used in other settings where tissue defects exist. It is a natural derivative like blood transfusion and can be applied on the part of the body, where natural mechanisms would need some bioengineering

Further investigation should be directed into measuring the comparative efficiency of this treatment. It should be compared to golden standard treatment and determine also novel

We showed that adding a platelet gel to a cancellous bone graft can help in retaining grafted bone from resorption and enhances its incorporation into adjacent bone. The standard platelet concentrates from the blood bank did not pose a significant risk for the affected patient. The results indicate good reasons for the application of this method in the treatment of bone defects

This is the first report of a prospective clinical study monitoring the use of allogeneic platelets mixed with autologous cancellous bone for the treatment of the non-union of long bones after fractures. Our new method of tissue engineering seems to have the potential to become a widely approved and accepted method of bone tissue replacement in the treatment of the non-

Last, but not least, it is worth noticing that the outdate rate of the platelet units is currently in the range of 8-27% of all prepared platelet units [52] This leads to the conclusion that the successful use of allogeneic platelets would significantly decrease the amount of wasted platelets, which could consequently favorably change the results of blood banking policies.

patient had to be reoperated only once again, because of poor implant ingrowth.

with no side effects related to the procedure.

336 Regenerative Medicine and Tissue Engineering

applications in bigger and smaller defects.

**2.7. Further research**

mid-size bone defects.

support.

**3. Conclusion**

in long bones.

union of long bones.

This work was partly supported by research grants J3-6290 and P3-0371 from the Slovenian Research Agency, ARRS, Trg OF 13, SI-1000 Ljubljana, Slovenia. No private company or pharmaceutical company funded this project.
