Introduction: Platelet-rich plasma (PRP) is a platelet concentration obtained from a few millilitres of blood. It releases several growth factors and can enhance tissue repair(). The aim of the study was to evaluate the efficacy and the safety of PRP in the treatment of experimental induced muscle lesions.

Materials and Methods: 22 adult Wistar rats were used. Blood collected from 2 rats was mixed with citrate-phosphate-dextrose and centrifuged to a gel consistency. Growth factor release was stimulated by the addition of CaCl and thrombin. Identical bilateral incisions were performed on the longissimum dorsi muscle of 20 Wistar rats. Each site was marked by placing a hollow PVC vessel containing PRP on the bottom of the defect. An empty marker was placed on the bottom of the contralateral lesion, as control. Animals were killed 40 or 60 days from surgery. Muscle samples were stained with haematoxylin-eosin. Histomorhometric parameters investigated were: number of regenerating fibres, amount of neoangiogenesis and fibrous tissue, presence of inflammatory cells, metaplasia, calcification and ossification (Leika, Quantimet SD).

Results: Treated muscles exhibited greater neoangiogenesis and a larger number of miocytes in regenerating phase compared with controls. Both groups showed a similar amount of fibrous tissue and some inflammatory cells. Metaplasia, ossification or heterotopic calcification were seen in none of the samples.

Conclusions: To our knowledge this is the first investigation of PRP in muscle healing. Data showed that PRP is effective in improve muscle healing without adverse local effects. Additional experiments are in progress in view of a clinical trial.

Purpose: The purpose of this biomechanical study is to compare the double reconstruction plate osteosynthesis versus double tension band osteosynthesis in the fixation of osteoporotic supracondylar humeral fractures.

Materials and Methods: Sixteen fresh cadavers (mean age: 75, range:70–80) were randomized into two experimental groups. Same supracondylar transverse humeral fractures were formed in both groups. Fractures in the first group, were fixed with double tension band technique using 2mm in diameter Kirschner wires and 1mm in diameter tension wires. Fractures in the second group, were fixed with double reconstruction plate osteosynthesis using 3,5mm reconstruction plates each fixing medial and lateral columns. Distal fragment was fixed with only one screw. Axial loading, maximum load, failure load and failure patterns were analysed. Statistical analysis was performed with SPSS 13.90 soft ware program. Groups were compared with Mann Whitney U test.

Results: Minimum load reqired for fracture displacement was statistically higher in double reconstruction plate osteosynthesis group (p< 0.005). Minumum load reqired for fixation failure was statistically higher in double reconstrution plate osteosynthesis group (p< 0,020).

Conclusion: Fracture healing mainly depends on a stable fracture fixation. Double plate ostesynthesis should be preferred over double tension band technique in osteoporotic supracondylar humeral fractures as it provides more stability.