Irreducible Traumatic Radial Head Dislocation Due to Annular Ligament Interposition in a Child with Ulnar Plastic Deformation: A Case Report.

BACKGROUND: The traumatic dislocation of the radial head in children is commonly treated by closed reduction. Sometimes, however, this strategy of treatment may not be effective due to the location of soft tissues in the radio-shoulder joint. The literature presents a few cases of the irreducible radial head dislocation with ulnar plastic deformation. Because it is a relatively rare condition, such a traumatic dislocation can be easily missed. Neglected injuries can lead to unwanted complications and unpredictable surgical outcomes. CASE PRESENTATION: This study presents a relatively rare case of traumatic radial head dislocation with ulnar plastic deformation in a 3-year-old child, which was successfully treated by open reduction. The examined case did not require osteotomy and ligamentous reconstruction. The initial attempt of closed reduction failed due to annular ligament interposition, which has been detected on MRI. After 3 months of treatment, the range of motion of the operated arm gradually improved. At the 6-month follow-up, the Mayo elbow-performance score indicated an excellent treatment outcome. CONCLUSIONS: The delayed treatment of radial head dislocation with ulnar plastic deformation can hinder the supination and pronation of the forearm, resulting in elbow/forearm deformity. The earlier this condition is detected, the easier it will be to treat it and the better the treatment outcome will be. The examined case of irreversible traumatic dislocation, successfully treated by open reduction, may help to treat radial head dislocation better.

UVB radiation and 17-hydroxygeranyllinalool diterpene glycosides provide durable resistance against mirid (Tupiocoris notatus) attack in field-grown Nicotiana attenuata plants.

Depending on geographical location, plants are exposed to variable amounts of UVB radiation and herbivore attack. Because the role(s) of UVB in the priming and/or accumulation of plant defence metabolites against herbivores are not well understood, we used field-grown Nicotiana attenuata plants to explore the effects of UVB on herbivore performance. Consistent with previous reports, UVB-exposed plants accumulated higher levels of ultraviolet (UV)-absorbing compounds (rutin, chlorogenic acid, crypto-chlorogenic acid and dicaffeoylspermidine). Furthermore, UVB increased the accumulation of jasmonic acid, jasmonoyl-L-isoleucine and abscisic acid, all phytohormones which regulate plant defence against biotic and abiotic stress. In herbivore bioassays, N. attenuata plants experimentally protected from UVB were more infested by mirids in three consecutive field seasons. Among defence metabolites measured, 17-hydroxygeranyllinalool diterpene glycosides (HGL-DTGs) showed strongly altered accumulation patterns. While constitutive HGL-DTGs levels were higher under UVB, N. attenuata plants exposed to mirid bugs (Tupiocoris notatus) had still more HGL-DTGs under UVB, and mirids preferred to feed on HGL-DTGs-silenced plants when other UVB protecting factors were eliminated by UVB filters. We conclude that UVB exposure not only stimulates UV protective screens but also affects plant defence mechanisms, such as HGL-DTGs accumulation, and modulates ecological interactions of N. attenuata with its herbivores in nature.