SUPPLEMENTATION OF OSTEOSYNTHESIS OF FEMUR BY AN INTERMEDULLARY NAIL – EXPERIMENTAL STUDY

Summary

Aim:
The subject of experimental studies of the treatment of bone defects is not only the osteosynthesis of bones itself, but also the search for an appropriate „filling“. The presented study is the continuance of the main part of the scientific research project, which was implemented in cooperation with the workplaces of Department of Paediatric Surgery, Orthopaedics and Traumatology, the Faculty Hospital Brno and University of Veterinary and Pharmaceutical Sciences of Brno, in the years 2012-2014. This scientific research project focused on the search for an appropriate biological and synthetic filling for a bone defect. The aim of the presented study is to evaluate whether more quality and quicker healing of the bone defect treated by means of standard bone graft method occurs, in case the fixation by an angle-stable plate is supplemented by intramedullary nailing using an elastic nail. The experimental model was a miniature pig.

Material and methods:
The experimental groups were made up of 13 miniature pigs. In 7 pigs the fragments of femur were fixed only by an angle-stable plate, in 6 pigs the fragments were fixed by an angle-stable plate supplemented by means of application of intramedullary Kirschner wire with the diameter of 3.0 mm. In both groups the bone defect, which occurred, was filled with autogenous bone graft. After healing, this area was processed from the histological point of view and evaluated with respect to the formation of new bone tissue and engraftment to the original bone in the area of the edges of the defect.

Results:
The results demonstrate that the tissue in the place where the bone defect occurred is more often evalua-ted as a mature bone after being fixed by an angle-stable plate, together with intramedullary fixation. The comparison was not significant from the point of view of statistics.

Conclusion:
The study demonstrated that the supplementation of osteosynthesis using an angle-stable plate in the femur where a large defect occurred (after being filled by means of autospongioplastics) by an intramedu-llary nail shows a more advanced and quality healing in the new bone than in case of osteosynthesis by means of splint itself. The results were not significant from the point of view of statistics, but they demonstrate a greater mechanical strength of combined osteosynthesis while preserving the miniinvasivity of intramedullary nail fixation.

Key words:
Bone defect, osteosynthesis, autogenous bone graft.