Artikel
A novel technique for simplified distal interlocking of IM nails to reduce radiation exposure
Suche in Medline nach
Autoren
Veröffentlicht: | 18. Oktober 2011 |
---|
Gliederung
Text
Questionnaire: The common practice for insertion of distal locking screws of intramedullary (IM) nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure to patient and surgical personnel. A new technique is introduced which guides the surgeon by landmarks on the X-ray projection. It was the aim of this study to investigate the newly developed guided freehand technique on human cadaveric below-knee specimens in an OR like environment and to compare it with the commonly used freehand technique in terms of operating time and radiation exposure.
Methods: 10 fresh frozen human below-knee specimens (incl. soft tissue) were used in the study. Each specimen was instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland) and was mounted on an OR-table providing an experimental setting close to surgical practice. Two distal interlocking techniques (freehand / guided freehand) were performed by an orthopedic resident surgeon in a random order. The newly developed guided freehand technique, generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the X-ray image. A computer program plans the drilling trajectory by 2D-3D conversion and provides said guiding landmarks in real-time. Interlocking holes can be drilled by visually aligning the drill to the planned trajectory. No additional tracking or navigation equipment is needed. A Siemens ARCADIS C-arm system (Siemens AG, Munich, Germany) was used as imaging means for all procedures. All four distal screws (2 mediolateral, 2 anteroposterior) were placed for each interlocking procedure. Each specimen was operated twice by either the freehand or the guided freehand technique. The nail was retrieved by 4-5 cm after the first procedure and was operated again. Operating time, number of taken X-rays and radiation time were recorded per procedure and for each single screw. Data was statistically evaluated using non-parametric tests.
Results and Conclusions: In total 8 procedures were performed with the freehand technique and 10 with the guided freehand technique. A 58% reduction in number of taken X-rays per screw was found for the guided freehand technique (7.4±3.4 X-rays) compared to the freehand technique (17.6±10.3 X-rays) (p<0.001). Total radiation time (all 4 screws) was 55% lower for the guided freehand technique (17.1±3.7 s) compared to the freehand technique (37.9±9.1 s) (p=0.001). Operating time (from first shot to screw tight) per screw was on average 3.2±1.2 min for the guided freehand technique and 4.1±2.1 min for the freehand technique (−22%, p=0.018). In an experimental setting, the newly developed guided freehand technique has proven to markedly reduce radiation exposure when compared to the conventional freehand technique. The method enhances established clinical workflows and does not require cost intensive add-on devices or extensive training.