Author/Editor     Merc, Matjaž; Drstvenšek, Igor; Vogrin, Matjaž; Brajlih, Tomaž; Rečnik, Gregor
Title     #A #multi-level rapid prototyping drill guide template reduces the perforation risk of pedicle screw placement in the lumbar and sacral spine
Type     članek
Vol. and No.     Letnik 133, št. 7
Publication year     2013
Volume     str. 893-899
ISSN     0936-8051 - Archives of orthopaedic and trauma surgery
Language     eng
Abstract     Introduction. The method of free-hand pedicle screw placement is generally safe although it carries potential risks. For this reason, several highly accurate computerassisted systems were developed and are currently on the market. However, these devices have certain disadvantages. We have developed a method of pedicle screw placement in the lumbar and sacral region using a multi-level drill guide template, created with the rapid prototyping technology and have validated it in a clinical study. The aim of the study was to manufacture and evaluate the accuracy of a multi-level drill guide template for lumbar and first sacral pedicle screw placement and to compare it with the freehand technique under fluoroscopy supervision. Materials and methods. In 2011 and 2012, a randomized clinical trial was performed on 20 patients. 54 screws were implanted in the trial group using templates and 54 in the control group using the fluoroscopy-supervised free-hand technique. Furthermore, applicability for the first sacral level was tested. Preoperative CT-scans were taken and templates were designed using the selective laser sintering method. Postoperative evaluation and statistical analysis of pedicle violation, displacement, screw length and deviation were performed for both groups. Results. The incidence of cortex perforation was significantly reduced in the template group; likewise, the deviation and displacement level of screws in the sagittal plane. In both groups there was no significantly important difference in deviation and displacement level in the transversal plane as not in pedicle screw length. The results for the first sacral level resembled the main investigated group. Conclusions. The method significantly lowers the incidence of cortex perforation and is therefore potentially applicable in clinical practice, especially in some selected cases. The applied method, however, carries a potential for errors during manufacturing and practical usage and therefore still requires further improvements.
Keywords     vretence
hrbtenica, sakralni predel
hrbtenica, ledveni predel
prostoročna metoda
fluoroskopija
navigacija
ortopedske kirurške metode, instrumentacija
vijak, namestitev
vertebra
sacral spine
lumbar spine
free-hand technique
fluoroscopy
navigation
orthopedic surgical procedures, instrumentation
screw placement