RT Journal Article
SR Electronic
T1 The Transverse Process Trajectory Technique: An Alternative for Thoracic Pedicle Screw Implantation—Radiographic and Biomechanical Analysis
JF International Journal of Spine Surgery
JO Int J Spine Surg
FD International Society for the Advancement of Spine Surgery
SP 8041
DO 10.14444/8041
A1 Lonner, Baron
A1 Verma, Kushagra
A1 Roonprapunt, Chanland
A1 Ren, Yuan
A1 Slattery, Casey A.
A1 Alanay, Ahmet
A1 Kassin, Gabrielle
A1 Castillo, Andrea
A1 Bazerbashi, Mohamad
A1 Buehler, Mark A.
A1 Kodigudla, Manoj K.
A1 Kelkar, Amey V.
A1 Serhan, Hassan
A1 Goel, Vijay
YR 2021
UL https://www.ijssurgery.com/content/early/2021/03/30/8041.abstract
AB Background This study evaluates the accuracy, biomechanical profile, and learning curve of the transverse process trajectory technique (TPT) compared to the straightforward (SF) and in-out-in (IOI) techniques. SF and IOI have been used for fixation in the thoracic spine. Although widely used, there are associated learning curves and symptomatic pedicular breaches. We have found the transverse process to be a reproducible pathway into the pedicle.Methods Three surgeons with varying experience (experienced [E] with 20 years in practice, surgeon [S] with less than 10 years in practice, and senior resident trainee [T] with no experience with TPT) operated on 8 cadavers. In phase 1, each surgeon instrumented 2 cadavers, alternating between TPT and SF from T1 to T12 (n = 48 total levels). In phase 2, the E and T surgeons instrumented 1 cadaver each, alternating between TPT and IOI. Computed tomography scans were analyzed for accuracy of screw placement, defined as the percentage of placements without critical breaches. Axial pullout and derotational force testing were performed. Statistical analyses include paired t test and analysis of variance with Tukey correction.Results Overall accuracy of screw placement was comparable between techniques (TPT: 92.7%; SF: 97.2%; IOI: 95.8%; P = .4151). Accuracy by technique did not differ for each individual surgeon (E: P = .7733; S: P = .3475; T: P = .4191) or by experience level by technique (TPT: P = .1127; FH: P = .5979; IOI: P = .5935). Pullout strength was comparable between TPT and SF (571 vs 442 N, P = .3164) but was greater for TPT versus IOI (454 vs 215 N, P = .0156). There was a trend toward improved derotational force for TPT versus SF (1.06 vs 0.93 Nm/degrees, P = .0728) but not for TPT versus IOI (1.36 vs 1.16 Nm/degrees, P = .74). Screw placement time was shortest for E and longest for T for TPT and SF and not different for IOI (TPT: P = .0349; SF: P < .0001; IOI: P = .1787) but did not vary by technique.Conclusions We describe the TPT, which uses the transverse process as a corridor through the pedicle. TPT is an accurate method of thoracic pedicle screw placement with potential biomechanical advantages and with acceptable learning curve characteristics.Clinical Relevance This study provides the surgeon with a new trajectory for pedicle screw placement that can be used in clinical practice.