No abstract

The most common mechanical complication was lateral migration of the helical blade; however, this rarely led to a clinical problem. Medial migration of the blade in the head without loss of reduction was the second most frequent complication. We have identified a new complication associated with the TFN, that is, medial perforation without loss of reduction. Blade migration in the head was less frequent when blades were placed inferiorly with a tip-apex distance of at least 15 mm.