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.

Mesomelia-synostoses syndrome (MSS) or mesomelic dysplasia with acral synostoses Verloes-David-Pfeiffer type is a rare autosomal-dominant disorder characterized by mesomelic limb shortening, acral synostoses, and multiple congenital malformations. So far, five patients in four unrelated families have been reported worldwide with MMS. By using whole-genome oligonucleotide array CGH, we have identified an interstitial deletion at 8q13 in all patients. The deletions vary from 582 Kb to 738 Kb in size, but invariably encompass only two genes: SULF1, encoding the heparan sulfate 6-O-endosulfatase 1, and SLCO5A1, encoding the solute carrier organic anion transporter family member 5A1. SULF1 acts as a regulator of numerous growth factors in skeletal embryonic development whereas the function of SLCO5A1 is yet unknown. Breakpoint sequence analyses performed in two families showed nonrecurrent deletions. Real-time quantitative RT-PCR analysis showed the highest levels of SULF1 transcripts in human osteoblasts and cartilage whereas SLCO5A1 was highly expressed in human fetal and adult brain and heart. Our results strongly suggest that haploinsufficiency of SULF1 contributes to this mesomelic chondrodysplasia, highlighting the critical role of endosulfatase in human skeletal development. Codeletion of SULF1 and SLCO5A1--which does not result from a low-copy repeats (LCRs)-mediated recombination event in at least two families--was found in all patients, so we suggest that haploinsufficiency of SULF1 combined with haploinsufficiency of SLCO5A1 (or the altered expression of a neighboring gene through position effect) could be necessary in the pathogenesis of MSS.

Mesomelic dysplasia is a heterogeneous group of rare bone diseases characterized by disproportionate shortness of middle segments of limbs and short stature. This study reports a male patient with an early diagnosed mesomelic dysplasia Kantaputra type (MIM*156232), characterized by symmetric, bilateral forearm and lower leg shortening with feet malformations and ankle-tarsal synostoses. As a result of several diagnostic biases in defining the mesomelic syndromes, we attempted to categorize symptoms and to clarify hitherto difficult discrimination between mesomeliae. Given that specific ankle joint alignment distortions seem to be pathognomonic for Kantaputra type (especially a fibulo-calcanear and, to a lesser extent, a tibio-talar synostosis), but not detectable with plane radiography, we encouraged use of MRI evaluation as an indispensable modality for proper diagnosis and further preoperative planning.

Fracture dislocation of the wrist is a rare injury in adolescents, and therefore it is easily ignored at the initial treatment. Once ignored, an alternative treatment such as proximal row carpectomy is indicated, but surgical outcome is not as good as that of an early reduction. We have experienced a chronic case of fracture dislocation in a 15-year-old, skeletally immature boy and treated it by scaphoid osteotomy, associated with bone grafting, screw fixation and ligament repair. The patient had no difficulties in daily activities nine years post-operatively, however the X-ray showed slight deformity of the scaphoid. Even for a chronic case, late reduction with ligamentous repair should be considered in adolescents.