The comparison of freehand fluoroscopic guidance and electromagnetic navigation for distal locking of intramedullary implants.

Introduction: In locking intramedullary nails, the most important problem is to put the distal interlocking screw accurately and quickly with minimum radiation exposure. The purpose of this clinical study was to compare the fluoroscopic time and surgical time required for distal locking with either free-hand fluoroscopic guidance or with an electromagnetic navigation system.
Materials and Methods: The study comprised 54 patients with 58 fractures of the lower extremity. The patients were divided in two groups: distal locking with freehand fluoroscopic guidance (group I) and distal locking with electromagnetic navigation (group II). The primary outcome in this study was fluoroscopy time. The secondary outcome was the operative time in distal interlocking.
Results: In group I, the mean operation time was 108 (81-135) min, the mean time for distal interlocking was 18.35 (9-27) min, the total fluoroscopy time was 47.77 (19-74) s, the mean fluoroscopy time during distal interlocking was 18.29 (2-29) s and the mean attempt at number of distal locking for two screws was 9.96 (2-18) times. In group II, the mean operation time was 80.96 (63-100) min, the mean time for distal interlocking was 7.85 (6.5-10) min, the total fluoroscopy time was 22.59 (15-32) s, the mean fluoroscopy time during distal interlocking was 1.62 (0-2) s and the mean attempt number of distal interlocking was 2 (2-2).
Conclusion: Fluoroscopy time to achieve equivalent precision is significantly reduced with electromagnetism-based surgical navigation compared with free hand fluoroscopic guidance. Also the operative time is significantly reduced with electromagnetic based navigation.
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