Fri., 10/14/11 Tibia, Paper #52, 11:37 am OTA-2011
The Insertion of Intramedullary Nail Locking Screws Without Fluoroscopy: A Faster and Safer Technique
Daniel S. Chan, MD1; Brandon Burris, MD2; Murat Erdogan, MD3;
H. Claude Sagi, MD1; Roy Sanders, MD1;
1Orthopaedic Trauma Service, Florida Orthopaedic Institute, Tampa, Florida, USA;
2University of South Florida, Tampa, Florida, USA;
3Ondokuz Mayis University, Samsun, Turkey
Purpose: This study was designed to compare standard free-hand (“perfect circles”) insertion of intramedullary nail (IMN) locking screws using fluoroscopic assistance (FA) against screw insertion using an electromagnetic (EM) tracking device. Our hypothesis was that EM would be simpler to use, require less time, and eliminate radiation.
Methods: This was a prospective, IRB-approved study. There were a limited number of EM units; therefore, this study could not be effectively randomized. Instead, when an EM unit was available it was used, and compared to screws placed with fluoroscopy, when it was not. Tibial and femoral locking screw insertion data were combined because the screw insertion technique was similar when used in either the femur or tibia for either method. Start to finish (incision to driver removal) time and mrads were recorded for each screw. Measurements collected for FA insertion included (1) technician arrival wait time, (2) radiation (mrads) and times for perfect circle set-up, (3) insertion time/screw, (4) fluoroscopic time and amount of radiation (mrads)/screw. As neither a technician nor a fluoroscopy unit was required for EM, data collected included EM set-up time and insertion time/screw. Data collected were then compared using standard analysis of variance.
Results: There were a total of 18 femoral (F) and 32 tibial (T) nails placed. 41 locking screws were inserted using the FA technique (16F/9T nails), while 60 screws were inserted using the EM technique (2F/23T). There were no missed insertions in either group. On average, technician wait time was 77 seconds with a perfect circle set-up time of 105 seconds. Average fluoroscopy time during this phase was 10 seconds, with 9.2 mrads exposure. FA screw insertion time averaged 342 seconds/screw (~5.5 minutes/screw) requiring 18 seconds of fluoroscopy time and 32.9 mrads of radiation. In the EM group, average set-up time was 94 seconds (1.56 minutes) and insertion time was 234 seconds/screw (~4 minutes/screw). This was significant (P = 0.006). There was also no radiation in this group. Direction of screw insertion was also evaluated; however, there were not enough in each subset for a clear evaluation.
Conclusions: When placing IMN locking screws, the use of EM decreases operative time as compared to standard techniques. In addition, accuracy is maintained, and as there is no radiation during this procedure, we conclude it is safer and faster than the standard fluoroscopic technique of “perfect circles.”
Alphabetical Disclosure Listing (628K PDF)
• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.