Abstract
Introduction: Several studies have looked at accuracy of thoracic pedicle screw placement, both in vivo and on cadavers, using fluoroscopy, image guidance, and anatomical landmarks. To our knowledge the upper thoracic spine (T1-T6) has not been specifically studied in the context of screw insertion and placement accuracy without the use of either image guidance or fluoroscopy. Our objective was to study the accuracy of placement of upper thoracic screws without the use of fluoroscopy, and report on implant related complications.
Methods: A single surgeon inserted a total of 60 screws in 13 consecutive non-scoliotic spine patients. These 60 screws were the first to be placed in the high thoracic spine in our institution. All previous surgeries used only a hook or wire technique for the upper thoracic spine. The most common diagnosis in our patient population was trauma. All screws were inserted using a modified Roy-Camille technique. Post operative axial computed tomography (CT) images were obtained for each patient and analyzed by an independent senior radiologist for placement accuracy. Furthermore we reviewed the operative records of each patient to record any implant related complications.
Results: No pedicle screw misplacements were found in 61.5% of the patients. Fifty three out of the 60 screws were placed correctly within all the pedicle margins. The overall pedicle screw placement accuracy was 88.3% using our modified Roy-Camille technique. Five medial and 2 lateral violations were noted in the 7 misplaced screws. One of the 7 misplaced screws was considered to be a marginal violation. No implant related complications were noted. Furthermore, no learning curve effect was noted as far as misplacement pattern was concerned.
Conclusion: We found that inserting pedicle screws in the upper thoracic spine based solely on anatomical landmarks was safe with an accuracy comparable to that of published studies on image guided surgery at the thoracic level.
Correspondence should be addressed to Ms Larissa Welti, Scientific Secretary, EFORT Central Office, Technoparkstrasse 1, CH-8005 Zürich, Switzerland
