Spine. Volume 35(24), 15 November 2010, pp 2109-2115

Clinical Acceptance and Accuracy Assessment of Spinal Implants Guided With SpineAssist Surgical Robot: Retrospective Study

Devito, Dennis P. MD*; Kaplan, Leon MD†; Dietl, Rupert MD‡; Pfeiffer, Michael MD§; Horne, Dale MD¶; Silberstein, Boris MD[//]**; Hardenbrook, Mitchell MD††; Kiriyanthan, George MD‡‡; Barzilay, Yair MD†; Bruskin, Alexander MD[//]; Sackerer, Dieter MD‡; Alexandrovsky, Vitali MD[//]; Stüer, Carsten MD§§; Burger, Ralf MD¶¶; Maeurer, Johannes MD[//][//]; Gordon, Donald G. MD***; Schoenmayr, Robert MD[//][//]; Friedlander, Alon MD†††; Knoller, Nachshon MD†††; Schmieder, Kirsten MD‡‡‡; Pechlivanis, Ioannis MD‡‡‡; Kim, In-Se MD[//][//]; Meyer, Bernhard MD**; Shoham, Moshe DSc**§§§. Author Information: From the *Children's Orthopedics of Atlanta, Atlanta, GA; †Hadassah University Hospital, Jerusalem, Israel; ‡Klinikum München Schwabing, Munich, Germany; §Helios Rosmann Hospital, Breisach, Germany; ¶Bethesda North, Cincinnati, OH; [//]Carmel Medical Center, Haifa, Israel; **Mazor Surgical Technology, Caesarea, Israel; ††Boston Spine Group, Newton, MA; ‡‡City Hospital Germany, Karlsruhe, Germany; §§Technical University of Munich, Munich, Germany; ¶¶Georg-August-University, Göttingen, Germany; [//][//]HSK-Klinikum Der Landeshauptstadt, Wiesbaden, Germany; ***Riverview Medical Center, Red Bank, NJ; †††Sheba Medical Center, Tel-Hashomer, Israel; ‡‡‡Medical Faculty, Mannheim University, Heidelberg, Germany; and §§§Technion-Israel Institute of Technology, Technion City, Haifa. © 2010 Lippincott Williams & Wilkins, Inc.

Study Design. Retrospective, multicenter study of robotically-guided spinal implant insertions. Clinical acceptance of the implants was assessed by intraoperative radiograph, and when available, postoperative computed tomography (CT) scans were used to determine placement accuracy.

Objective. To verify the clinical acceptance and accuracy of robotically-guided spinal implants and compare to those of unguided free-hand procedures.

Summary of Background Data. SpineAssist surgical robot has been used to guide implants and guide-wires to predefined locations in the spine. SpineAssist which, to the best of the authors' knowledge, is currently the sole robot providing surgical assistance in positioning tools in the spine, guided over 840 cases in 14 hospitals, between June 2005 and June 2009.

Methods. Clinical acceptance of 3271 pedicle screws and guide-wires inserted in 635 reported cases was assessed by intraoperative fluoroscopy, where placement accuracy of 646 pedicle screws inserted in 139 patients was measured using postoperative CT scans.

Results. Screw placements were found to be clinically acceptable in 98% of the cases when intraoperatively assessed by fluoroscopic images. Measurements derived from postoperative CT scans demonstrated that 98.3% of the screws fell within the safe zone, where 89.3% were completely within the pedicle and 9% breached the pedicle by up to 2 mm. The remaining 1.4% of the screws breached between 2 and 4 mm, while only 2 screws (0.3%) deviated by more than 4 mm from the pedicle wall. Neurologic deficits were observed in 4 cases yet, following revisions, no permanent nerve damage was encountered, in contrast to the 0.6% to 5% of neurologic damage reported in the literature.

Conclusion. SpineAssist offers enhanced performance in spinal surgery when compared to free-hand surgeries, by increasing placement accuracy and reducing neurologic risks. In addition, 49% of the cases reported herein used a percutaneous approach, highlighting the contribution of SpineAssist in procedures without anatomic landmarks.