Unlike other mechanisms of injury in which pulmonary contusion is often found alongside other injuries, explosions can cause pulmonary contusion without damage to the chest wall.In addition to blunt trauma, penetrating trauma can cause pulmonary contusion. Contusion resulting from penetration by a rapidly moving projectile usually surrounds the path along which the projectile traveled through the tissue. The pressure wave forces tissue out of the way, creating a temporary cavity; the tissue readily moves back into place, but it is damaged. Pulmonary contusions that accompany gun and knife wounds are not usually severe enough to have a major effect on outcome;  penetrating trauma causes less widespread lung damage than does blunt trauma. An exception is shotgun wounds, which can seriously damage large areas of lung tissue through a blast injury mechanism. Mechanism
The physical processes behind pulmonary contusion are poorly understood. However, it is known that lung tissue can be crushed when the chest wall bends inward on impact. Three other possible mechanisms have been suggested: the inertial effect, the spalling effect, and the implosion effect. In the inertial effect, the lighter alveolar tissue is sheared from the heavier hilar structures, an effect similar to diffuse axonal injury in head injury. It results from the fact that different tissues have different densities, and therefore different rates of acceleration or deceleration. In the spalling effect, lung tissue bursts or is sheared where a shock wave meets the lung tissue, at interfaces between gas and liquid.
Acromicric dysplasia is an extremely rare inherited disorder characterized by abnormally short hands and feet, growth retardation and delayed bone maturation leading to short stature. Most cases have occurred randomly for no apparent reason (sporadically). However, autosomal dominant inheritance has not been ruled out. The disorder is different (but similar to) from other syndromic entities such as geleophysic dysplasia, Weill-Marchesani syndrome, and Myhre syndrome. Genetics
This condition has been associated with mutations in the Fibrillin 1 (FBN1) gene.Mutations in this gene have also been associated with stiff skin syndrome, Marfan syndrome and its variant Marfanoid–progeroid–lipodystrophy syndrome, autosomal dominant Weill-Marchesani syndrome, isolated ectopia lentis, MASS phenotype, and Shprintzen-Goldberg syndrome. References
External links
GeneReview/NIH/UW entry on Geleophysic Dysplasia