Easy method to simplify “freehand” subaxial cervical pedicle screw insertion

Abstract

Study Design:Technical note.Objectives:The objective of this study is to check out safety and rationality of standardized and fast tricks to select trajectory of subaxial cervical pedicle screw (SCPS) insertion, based on simple angles to bony landmarks.Materials and Methods:Stage 1 – Computed tomography (CT)-morphometric analysis of C3–C7 vertebrae of ten patients with cervical degenerative diseases. Stage 2 – SCPS insertion in 6 cadavers, according to the developed technique (59 pedicle screws). Stage 3 – SCPS insertion in 6 patients, according to the developed technique (32 pedicle screws).Results:CT-morphometric analysis showed that the average length of C3–C7 pedicle channels was 32 mm, the average angle between a pedicle axis and an axis of contralateral lamina - 180°, the average angle between a pedicle axis and plane of a posterior surface of a lateral mass amounted to 90° and the coordinates of an optimal entry point – 2 mm from a lateral edge and 2 mm from an upper edge of the lateral mass posterior surface. During the cadaveric study, 39 screws had a satisfactory position (66.1%), 7 screws permissible (11.9%), and 13 screws unacceptable (22%). During the clinical study, 26 screws (81.25%) had satisfactory position, 4 (12.5%) had permissible position, and 2 (6.25%) unacceptable position.Conclusion:Developed and clinically approved a method for simplicity SCPS insertion is relatively safe and cheap. No doubt, it requires further investigation, but the results of primary analysis allow us to recommend it to wide practical application.

Pedicle Screw Fixation for Hemiplegia and Bilateral Hypoesthesia Due to C2-C3 Spinal Fracture Dislocation

“…The ligamentous complex connecting the occiput to C2, which ensures occipitocervical stability, remains undamaged. Choosing the screw insertion angle intraoperatively is challenging, and even the tiniest deviation can result in screw malpositioning 21,22 . Computer navigation-assisted fixation is useful for accurate placement of CPS without risking the neurovascular structures 23 , but is unavailable in most developing countries, such as Indonesia; therefore, anatomic knowledge as a surgeon is paramount.…”

Validation of Freehand Cervical Pedicle Screw Placement in Subaxial Spine Using the “Burcev Technique”: A Cadaveric Study

“…Several anatomical and clinical studies have been performed on CPS fixation, with each study having unique trajectories, tricks, and tips to avoid pedicle breach. 4 8 9 10 11 12 13 14 15 16 17 18 However, these “freehand techniques” have not gained widespread popularity among spine surgeons. The last two decades have been an era of digital navigation, and robotic technology has improved the CPS placement technique.…”

“…Our findings for CPS placement are concurrent with those described by the original authors. 8 The “Acceptable” (combined “satisfactory” and “Permissible”) percentage of the CPS is same as described by them. We strictly adhered to the author’s method and did not apply the modifications such as “burring deep” described by Abumi et al, use of a smaller probe, sliding method, or a small laminotomy for tactile perception reported by other authors that could have improved the results.…”

“…One assistant (S.P.) steadied the cadaver, and one spine surgeon (M.J.) performed the procedure described by Burcev et al by using a “freehand technique.” 8 Only the subaxial spine C3–6 was instrumented, omitting the C7, which is now an established technique. The entry point for the CPSs was 2-mm medial and inferior to the facet joint between the involved and rostral vertebrae at a trajectory parallel (180 degrees) to the contralateral lamina and at an angle of 90 degrees to the sagittal plane ( Fig.…”

“…In 2017, Burcev et al described a “freehand” technique, which they described as an “easy and fast method” for safe CPS placement. 8 Although the anatomical observation of the authors was appealing and straightforward, none of the authors have reiterated their findings. The present study aims to validate the “freehand technique,” described by the authors, in Indian cadavers.…”