Distrator ósseo craniano de acionamento magnético percutâneo

Abstract

Craniosynostosis occurs as a result of the absence or premature closure of one or multiple cranial sutures. Its treatment aims at correcting the esthetic defects as well as to control the intra-cranial pressure. The use of internal bone distractors is a valuable surgical option, promoting direct bone movement, and thus modifying the skull contours. This dissertation includes the description of the development and bench testing of a magnetic calvarial bone distractor remotely activated. The distractor is made out of four parts, all prototyped using resin: the cursor, the base, the one-way locking system and the protection cap. The activation system is composed by one internal iron-magnetic plate, one external activation magnet and two fixation screws. The test bench was designed to simulate the expected forces to which the distractor should counteract. The bench testing showed that the magnetic coupling between the external magnet and the iron-magnetic plate was strong enough for the distractor to carry out a maximum 28-mm distraction, being equivalent to a 10.88 N force. The one-way locking system was efficient in preventing the distractor cursor to recede, maintaining the gap between the two plates stable.