No abstract

Friedreich ataxia (FRDA) is a progressive neurodegenerative disease with developmental features caused by a genetic deficiency of frataxin, a small, nuclear-encoded mitochondrial protein. Frataxin deficiency leads to impairment of iron–sulphur cluster synthesis, and consequently, ATP production abnormalities. Based on the involvement of such processes in FRDA, initial pathophysiological hypotheses focused on reactive oxygen species (ROS) production as a key component of the mechanism. With further study, a variety of other events appear to be involved, including abnormalities of mitochondrially related metabolism and dysfunction in mitochondrial biogenesis. Consequently, present therapies focus not only on free radical damage, but also on control of metabolic abnormalities and correction of mitochondrial biogenesis. Understanding the multitude of abnormalities in FRDA thus offers possibilities for treatment of this disorder.

No abstract

Intramedullary screw fixation has been found to be a reliable treatment for certain fractures of the fifth metatarsal. Techniques for this treatment have been described relying largely on intraoperative fluoroscopy. Ten human cadaver specimens had their fifth metatarsals osteotomized and underwent retrograde intramedullary pin placement. Anatomic landmarks and the location of the sural nerve in relation to this starting point were measured. The trajectory of a pin reducing the osteotomy was analyzed. Using the resultant starting point and guide pin trajectory, intramedullary screw placement was performed reliably without the aid of fluoroscopy. This study demonstrates that intramedullary screw fixation of proximal fifth metatarsal fractures may be performed with the use of anatomic landmarks, which decreases the amount of intraoperative fluoroscopy needed.