Percutaneous Pedicle Screws Positioning by means of the “Scotty Dog” Imaging Monitoring Technique in Spine Surgery: A Case Series

Abstract

Objectives Vertebrae, when looked at in x-rays with oblique incidence (45 degrees), seem similar in shape to a Scottish Terrier dog. The "Scotty Dog" incidence is commonly used in spinal pain treatments such as radiofrequency and transforaminal blockages for correct insertion of the needle, because it allows complete visualization of the pedicle. The objective is to describe a series of cases of spinal surgery using the "Scotty Dog" monitoring technique and to evaluate safety. Methods In this study, we describe all consecutive patients operated by the same surgeon from August 2011 to August 2012 using the "Scotty Dog" technique of fluoroscopic monitoring. Patients were operated for spondylolisthesis, lumbar canal stenosis, spinal disc herniations, and fractures. All patients underwent computed tomography (CT) after surgery to confirm the correct positioning of screws. Results During the study period, 42 patients with a mean age of 64.5 years underwent operation, most of them for spinal disc herniation correction. In all cases, visualization of the pedicle was possible in all its length and no case of foramen invasion was registered. Surgical time was 98 minutes on average, with no need for transfusion or complications requiring admission to the ICU. There was one case of infection. Conclusions The Scotty Dog technique for imaging monitoring of the spine provides easy visualization of the whole pedicle, allowing a safe screw insertion. In this case series, there was no case of foramen invasion.