The aim of our study was to investigate the effect of platelet-rich plasma on the proliferation and differentiation of rat bone-marrow cells and to determine an optimal platelet concentration in plasma for osseous tissue engineering. Rat bone-marrow cells embedded in different concentrations of platelet-rich plasma gel were cultured for six days. Their potential for proliferation and osteogenic differentiation was analysed. Using a rat limb-lengthening model, the cultured rat bone-marrow cells with platelet-rich plasma of variable concentrations were transplanted into the distraction gap and the quality of the regenerate bone was evaluated radiologically.

Cellular proliferation was enhanced in all the platelet-rich plasma groups in a dose-dependent manner. Although no significant differences in the production and mRNA expression of alkaline phosphatase were detected among these groups, mature bone regenerates were more prevalent in the group with the highest concentration of platelets.

Our results indicate that a high platelet concentration in the platelet-rich plasma in combination with osteoblastic cells could accelerate the formation of new bone during limb-lengthening procedures.

We report a femoral shaft fracture that reduced spastic muscle hypertonus of the affected lower limb of a child with cerebral palsy. The child was a five years old boy. He was borne with spastic quadriplegia (total body involvement). He could not sit, stand and walk by himself. The femoral shaft fracture occurred during physiotherapy. The injury itself was iatrogenic although the bones were accompanied by roentgenological bone atrophy. Such bone atrophy comes from disuse or low physical activity.

The fracture was treated by a hip spica cast. The femoral bone was shortened at the time of immobilization. After removing the cast, the spastic muscle hypertonus was apparently reduced. This instructive case suggests osteotomy as a new effective treatment for spastic hypertonus. Osteotomies would make few scars in the muscles and tendons comparing to lengthening of multiple tendons and muscles. In this case, osteotomies are believed to be a non-invasive treatment rather than other available operative procedures.