[Fluoroscopy based surgical navitation vs. mechanical guidance system for percutaneous interventions. A controlled prospective study exemplified by distal locking of intramedullary nails].

The aim of this study was to directly compare mechanically based targetting and surgical navigation when applied for percutaneous osteosynthesis. The distal locking procedure of intramedullary nails was used as the clinical model for a controlled prospective study. A total of 50 patients were included in two groups. In group 1, the distal locking was done with a mechanical aiming device while in group 2 this was done using a fluoroscopy based surgical navigation system. The target parameters were the precision attained, the necessary operation and fluoroscopy times as well as the number and severity of intra-operative problems. The drill-bit failed to pass through the interlocking hole in one patient with mechanical guidance and in two patients with surgical navigation. The average procedure time for distal locking with mechanical guidance was 6.9 minutes compared with 37.6 minutes with surgical navigation. An additional 44 minutes were required before skin incision and after skin closure as setup time for the navigation system. There was no significant difference in the fluoroscopy time or in the number of intra-operative technical problems. Surgical navigation increased the demand for resources but failed to improve the precision of distal locking compared with mechanical guidance. Further clinical studies are required to determine to what degree these results, using a special model, relate to other applications.