Osteogenesis imperfecta and rheumatoid arthritis: connective issues

The coexistence of osteogenesis imperfecta and inflammatory arthritis has been very rarely described. Nevertheless, systemic inflammation has been found in osteogenesis imperfecta. The COL1A1 mutations may affect collagen synthesis as well as post-translational modifications, extracellular matrix interactions, and receptor-mediated signaling. Major collagen binding ligands forming the interactome, such as cytokines, cell adhesion molecules, matrix metalloproteinases, proteoglycans, and other molecules, are autoimmunity targets involved in rheumatoid arthritis pathogenesis. Cross-talk between bone remodeling and inflammatory pathways involving osteoclasts is important in osteogenesis imperfecta and rheumatoid arthritis. In osteogenesis imperfecta, the structural abnormalities and repeated traumatism, including fractures, could activate locally the innate immunity and trigger arthritis, similar to post-traumatic arthritis. Currently, the therapy of osteogenesis imperfecta is a suboptimally met need. Understanding the complex putative pathogenic links between osteogenesis imperfecta and inflammatory arthritis could hopefully lead to new therapeutic targets. Raising awareness regarding a possible association between osteogenesis imperfecta and arthritis could help improve the quality of life in these patients.

[Facial trauma and injury in children]

Facial traumas are common in children but often unconsidered. Facial injury is responsible of impressive bleeding because of the rich vascularization of the face; this bleeding is often underestimated because of the immediate arterial vasoconstriction that is very strong for children. The blood volume is 80ml/kg for a newborn, with a total of 250ml, reaching 70ml/kg at one year of age. The evaluation must be rigorously performed due to the risk of a sudden decompensation. Regarding the wounds, the primary repair must be performed directly neat or optimal in case of damaged tissues. The rule is to keep maximum of the integrity and to limit debridement. Careful repair often requires general anesthesia, especially in young children, to facilitate a perfect joining of the edges and of the mucocutaneous lines. Losses of substance should be treated by directed cicatrization. Flaps are never performed in children as a first intention for reasons developed below. Given the elasticity of the facial skeleton, fractures require a brutal shock to occur, but the clinical signs can be misleading. For instance, too specific and sometimes ignored, fractures can show weakly symptomatic signs : the fractures of the condylar and the orbital floor, with their respective complication that are temporomandibular bone ankylosis and definitive diplopia. Possible children abuse should be suspected in case of different age lesions and discrepancies between the told story and types of injuries. Once the vital urgency is eliminated, the orbital emergency should be first considered in facial traumas within the ophthalmology specialty because wounds and contusions of the globe are often under-evaluated and threaten the vision. The second emergency is the orbital floor fracture in its 'trapdoor' type, specific to the child. Combined with a motionless eye and uncontrollable vomiting, this is the second true urgency because it involves the prognosis of the oculomotricity and requires emergency surgery. Finally, dental trauma should not be overlooked because of their functional and aesthetic consequences. Primary cicatrization is usually rapid but scars remain inflammatory during a long time. The risk of hypertrophy exists in case of contusions and lacerations associated with wounds but also during puberty and in some locations. Age interfere with the result because growth will either improve or worsen the initial result, depending on the location and mechanism. The secondary specialized and prolonged managing and monitoring is capital on the functional, aesthetic and psychological points of view.