eposter: Prospective evaluation of a free-hand...

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1 PROSPECTIVE EVALUATION OF A FREE-HAND ELECTRICAL CONDUCTIVITY MEASURING DEVICE TO REDUCE RADIATION EXPOSURE DURING FLUOROSCOPICALLY ASSISTED OPEN OR MINIMALLY INVASIVE PEDICLE SCREW ARTHRODESIS. Alphonse Lubansu, Landry Drogba, Joseph Masudi, Olivier Dewitte Department of Neurosurgery, Erasme Hospital, Brussels, Belgium

2 eposter: Prospective evaluation of a free-hand..... Author Alphonse Lubansu Landry Drogba Joseph Masudi Olivier Dewitte Relationships Disclosed No Relationship No Relationship No Relationship No Relationship

3 Open (PPSF) vs Minimally Invasive (MIS) Posterior Spine arthrodesis First concern: Pedicle screw misplacement Published rates of misplaced pedicle screws Roy-Camille et al (1987) 10% Robbins et al (1987) 28% Weinstein et al (1988) 21% Gertzbein et al. (1990) 28% Jerosch et al (1992) 40% Saillant (1995) 22,2% Laine et al. (1999) 13% to 21% Toleikis (2002) 5,4% to 40%

4 PEDIGUARD First free-hand perforation instrument to detect iatrogenic breach in the vertebral pedicle Local tissues electrical conductivity is monitored at the tip of the instrument: When the electrical conductivity at the distal part of the instrument changes, you will be alerted thanks to: A variation of sound cadence A variation of sound pitch A variation of LED flashing rate σ σ(cancelous Bone) σ (Soft Tissue) FDA Approved σ(cortical Bone) The electrical conductivity is the property of a material to let the current flow. (Opposite =Impedance) Electrical conductivity measurement: a new technique to detect iatrogenic initial pedicle perforation Ciaran Bolger Æ Michael O. Kelleher Æ Linda McEvoy Æ M. Brayda-Bruno Æ A. Kaelin Æ J.-Y. Lazennec Æ J.-C. Le Huec Æ C. Logroscino Æ P. Mata Æ P. Moreta Æ G. Saillant Æ R. Zeller Eur Spine J (2007) 16:

5 Open (PPSF) vs Minimally Invasive (MIS) Posterior Spine arthrodesis Second concern: Radiation exposure Estimation of Spine Surgeon dose and associated radiogenic risks Limited hand annual exposure could be reach if repeated operation with prolonged time of fluoroscopy Estimation of patient dose and associated radiogenic risks

6 Aim of our study... Evaluated if PEDIGUARD is an helpful tool to reduce the radiation exposure during posterior open and MIS arthrodesis using pedicle screws? Prospective, controlled study to compare patient/ surgeon radiation exposure during open vs MIS posterior arthrodesis help or not by PEDIGUARD

7 Materials and methods: q Prospective comparative study q 45 patients - 30 H /24 F (Mean age: 50 yrs (18-72 yrs) q Four Study groups: A. Open-PPSF help by fluoroscopy alone B. Open-PPSF help by fluoroscopy and Pediguard C. MIS-PPSF help by fluoroscopy alone D. MIS-PPSF help by fluoroscopy and Pediguard q Surgical procedure - Posterior pedicle screw fixation (PPSF) +/- Interbody fusion (PLIF/TLIF) through MIS or Open approach q Evaluation: q Rate of optimal screw placement (CT in postoperative ) q Patient radiation exposure q Surgeon radiation exposure

8 Materials and methods: q Postoperative radiological control (J4) by CT and standard RX q Positioning of screws evaluated by independent radiologist (Youkilis (1) classification) (1) source: Youkilis et al. Neurosurgery (2001), 46(4), pp q Radiation measurement Thermoluminescent Dosimeter LiF100 Radiations Measured range fading Photon, energies >5 kev Neutron, thermal to 100 MeV Electron/beta, energies >70 kev 10 µgy to 1 Gy (1 mrad to 100 rad) linear 1 Gy to 20 Gy (100 rad to 2000 rad) supralinear <20% in 3 months without thermal treatment <5% in 3 months using preheat or glow curve deconvolution Threshold: <10 µgy (1 mrad) based on 2.26 STD DEV of 10 repeat readings of an unexposed dosimeter. Energy Response 30 kev/cobalt 60: 1,25 Relative sensitivity to 1MeV photon 1 <0.2% of reading, over the range, without annealing Residual TL Signal:

9 Results: q Study groups A. Open-PPSF + RX (n=15) 9 men/6 women (mean age: 56 yrs (42-72)) B. Open-PPSF + Pediguard (n=15) 10 men/5 women (mean age: 48 yrs (30-69)) C. MIS-PPSF + RX (n=15) No demographic statistical difference 8 men/7 women (mean age: 45 yrs (19-70)) D. MIS-PPSF +Pediguard (n=15) 7 men/8 women (mean age: 51 yrs (34-65)) q No misplacement observed in both groups

10 Results: Study group Group A Open PPFS +RX Group B Open PPFS +PD Rx Time Exp. Thyr (µsv) Exp. Occul (µsv) Exp. Gonad (µsv) Exp. AP (µsv) Exp. Lateral (µsv) 3,93 251,87 181,12 360, , ,10 2,61 219,23 119,13 317, , ,12 Exposure change (%) - 33 % -12 % - 33 % - 12 % - 71 % - 55 % Statist diff. (p) <0,05 NS NS NS <0,05 <0,05 Group C MIS-PPFS +RX Group D MIS-PPFS +PD 6,63 308,63 178,17 475, , ,76 1,79 150,74 107,74 183, , ,68 Exposure change (%) - 73% - 51% - 40 % - 61 % - 21 % - 61 % Statist diff. (p) <0,01 <0,05 NS <0,05 NS <0,05 Statistical difference between both groups

11 Conclusions: PEDIGUARD Our preliminary results demonstrate that... PediGuard is a promising easy-to-use tools to improve the rate of optimal screw placement and... significantly reduce the radiation exposure for the patients reduce the surgeon exposure of 12 to 33% in open PPSF and of 40 to 61 % in MIS PPSF