Effect of autologous platelet-rich plasma on distraction osteogenesis in the mandible of rabbits: a morphologic and morphometric approach.

Distraction osteogenesis of the jaw is a common surgical practice in the treatment of pediatric craniofacial deformities. Autologous platelet rich plasma (PRP) has been used to increase the healing potential of bones in humans during distraction osteogenesis. This article aims to study the morphometric and morphologic parameters resulting from the effect of PRP on bone healing after mandibular distraction in rabbits. Right mandibular distraction was performed in 12 rabbits divided equally into 2 groups. PRP and physiological saline were injected, according to a defined protocol, in the callus following distraction of the experimental and control groups respectively. The rabbits were sacrificed after a consolidation period of 45 days and the mandibles were surgically removed. Bone mineral density, radiographic analysis, mechanical properties and histological features of the lengthened bones were assessed using radiographic examination, dual X-ray absorptiometry, biomechanical testing and histology. Results showed that the regenerate bone density, the amount of trabeculation in addition to the bone mineral density and mineral content, as measured by absorptiometry, were better with PRP but not significantly different between groups. Two radiographs revealed a more consistent healing in the experimental mandibles compared with erratic outcomes in corresponding controls. Two of the latter could not be subjected to any mechanical testing because the mandibular parts, connected with fibrous tissue, were separated. Consequently, the biomechanical test depicted greater maximal loads in the experimental group. The histological studies exhibited more ossification and less connective tissue fibers in the experimental group. PRP accelerated healing of mandibles in rabbits following distraction and improved their biomechanical properties. These findings have significant clinical implications on reducing the period of consolidation of the mandibles which may not be immobilized like other bones for long periods of time.

[Practical implementation and usefulness of guidelines for the management of syncope: a professional practice study]. / Application pratique et intérêt des recommandations de prise en charge des syncopes : évaluation de pratiques professionnelles.

AIMS: To assess the practical implementation of international guidelines and their impact on syncope management in a 500-bed general hospital. PATIENTS AND METHODS: Three groups of 63 consecutive patients admitted for syncope to the emergency care unit (ECU) were studied: group 1, before the guidelines delivered to the practitioners, group 2 immediately after the diffusion of guidelines and group 3, one year later. The study evaluates the mean duration of stay (MDS) and the relevance of the diagnostic strategy. RESULTS: In group 1 compared to group 2, MDS were respectively 6.8±5.5 and 5.4±2.8 days (P=0.07) and the unexplained syncope number respectively 22% and 24% (P=0.8). The search of orthostatic hypotension became more systematic (13% versus 86% in group 1 and 2 respectively, P<0.001). The agreement (kappa coefficient) between initial and final diagnostic increased in 0.34 to 0.44. One year later MDS in group 3 was 7.1±4.7 days (P=0.8 versus group 1 and P=0.015 versus group 2) with only 6.3% systematic search for orthostatic hypotension (P<0.001). CONCLUSIONS: Guidelines optimize the syncope management in the ECU and the agreement between the emergency and discharge diagnostic without change of unexplained syncope and. MDS tend to be shorter when guidelines are actively implemented. Nevertheless, the positive impact of guidelines implementation is of limited duration.