Reducing Pedicle Drilling Radiation by using Dynamic Surgical Guidance with a Jamshidi Needle while Maintaining Screw Placement Accuracy: A Cadaver Study

Presented at SMISS Annual Forum 2018
By John Williams MD
With J. Joseph , B. Smith , M. Kirsch , A. Sabbagh , P. Park ,

Disclosures: John Williams MD B; SpineGuard. J. Joseph None, B. Smith None, M. Kirsch None, A. Sabbagh None, P. Park None,


Fluoroscopy usage during MIS spine surgery is necessary however the amount of radiation the surgeon receives is of great concern. DSG (Dynamic Surgical Guidance) provides real time feedback without the use of harmful radiation. DSG has the ability to detect change in tissue density. There is a clear and definable gradient between cancellous bone, cortical bone and soft tissue. Therefore, when the tip of the DSG Jamshidi is up against the cortex, the sound changes significantly, thereby warning the surgeon of impending drilling through the pedicle wall or the vertebral body cortex by the DSG enhanced Jamshidi. the DSG.


The aim of this cadaver pilot trial was to determine the efficiency of reducing radiation during pedicle preparation in minimally invasive posterior spine fusion surgery by using


Two fresh frozen cadaver specimens were specially prepared with saline soaking for this study Two spine surgeons, each with over 15 years of minimally invasive spine surgery experience were randomly and blindly directed on which level and side to prepare and with which device; DSG Jamshidi or standard Jamshidi. Surgeons used fluoroscopy to locate the entry point of the randomized pedicle. Once the entry point was identified the surgeons were instructed to use either the DSG Jamshidi or the standard Jamshidi needle to do the pedicle drilling according to a randomization table. The number of fluoroscopy shots were recorded using both anteroposterior and lateral fluoroscopy images for completion of the pedicle drilling and a K wire placed. Once levels T10-L5 were completed on all specimens final fluoro xrays were obtained as were CT scans were performed looking for pedicle screw breaches >/=2mm. A total of 16 screws were placed in each specimen for a total of 32 screws in our trial.


DSG showed a 86.8% reduction of total fluoroscopy shots in MIS posterior spine surgery in 16 pedicle drillings. This was accomplished while reducing the screw breech rate by 60%.


Our randomized trial demonstrated the use of a Jamshidi type needle with Dynamic Surgical Guidance was able to reduce radiation by 87% and improve pedicle screw breach rate by 60% in this cadaver study of MIS posterior thoracolumbar surgery.