To Err Is Human - Is Surgical Precision Infallible? Concept of Acceptable 'Errors' with Evaluation of 577 Cervical Pedicle Screw Placements

Abstract

Background: Society at large does not accept in technique, though are common in practice. Authors introduce the concept of errors and propose a new for assessment of cervical pedicle screw placement in the lower cervical spine, which is technically a difficult procedure. Cadaveric studies have often discouraged placement of cervical pedicle screws due to high misplacement rates (25% to 87.5%). However, clinical results have shown minimal screw related complications. Methods: 99 patients operated between Dec 2011 and June 2017 were included in the study with average age of 49 years (18 to 80 years). All patients underwent postoperative CT scans for evaluation of screw placements. Findings: A total of 577 pedicle screw placements (C3 to C7) were assessed in 99 patients using the conventional grading of screw perforations and (AEC). There were 115 (19.93%) screw perforations with 74 (12.82%) grade-I medial perforations, using the conventional perforation grading. The same set of screws were assessed using the Acceptable classification which showed 529 screws (91.68%) as acceptable placements and 48 screws (8.31%) having unacceptable placements. Interpretation: The present study reinforces earlier clinical studies reporting minimal clinical complications despite having cervical pedicle screw misplacements ranging from 15 to 20%. The concept of acceptable seems to bridge the gap between the high radiological screw misplacement rates and the low clinical complications. Although the main strength of the study is in the clear definition of the errors in placement of cervical pedicle screws, the concept of acceptable needs to be handled carefully. concept may initiate a shift in the perception of infallibility of surgical precision by the common man. Funding Statement: No Funds were received from any of the authors or institution for the purpose of the study. Declaration of Interest: The primary author (BM) has financial remunerations from Medtronic India as part of consultant services. The corresponding author (BU) has received research grant (Paid to the institution) from Medtronic India. Ethics Approval Statement: There was no objection from the institutional ethical committee for the study, as it involved only retrospective evaluation of patient data.