scholarly journals Application of patient-specific 3D navigation templates for pedicle screw fixation of subaxial and upper thoracic vertebrae

2019 ◽  
Vol 16 (2) ◽  
pp. 35-41 ◽  
Author(s):  
R. A. Kovalenko ◽  
V. V. Rudenko ◽  
V. A. Kashin ◽  
V. Yu. Cherebillo ◽  
D. A. Ptashnikov
Keyword(s):  
Pedicle Screw ◽  
Thoracic Spine ◽  
Bone Structure ◽  
Pedicle Screws ◽  
Patient Specific ◽  
Thoracic Vertebrae ◽  
3D Navigation ◽  
Average Deviation ◽  
Upper Thoracic Spine ◽  
Upper Thoracic

Objective. To analyze the safety and accuracy of pedicle screw placement in the subaxial cervical and upper thoracic spine using patient-specific 3D navigation templates.Material and Methods. The study included 16 patients who underwent transpedicular implantation of screws in the subaxial cervical and upper thoracic vertebrae using patient-specific 3D navigation templates. A total of 88 screws were installed. All patients underwent preoperative CT angiography to assess visualization of the vertebral artery. Customized vertebral models and navigation templates were created using 3D printing technology. Models and templates were sterilized and used during surgery. The results of screw implantation, as well as the safety and accuracy of the placement, were assessed by postoperative CT.Results. The average deviation from the planned trajectory was 1.8 ± 0.9 mm. Deviation was estimated as class 1 (<2 mm) for 57 (64.77 %) screws, class 2 (2–4 mm) for 29 (32.95 %), and class 3 for two (2.27 %). The safety of screw implantation of grade 0 (the screw is completely inside the bone structure) was in 79 (89.77 %) cases, of grade 1 (<50 % of the screw diameter perforates the bone) – in 5 (5.68 %), and of grade 3 – in 2 (2.27 %).Conclusion. Using 3D navigation templates is an affordable and safe method of installing pedicle screws in the cervical and upper thoracic spine. The method can be used as an alternative to intraoperative CT navigation.

scholarly journals Novel free-hand T1 pedicle screw method: Review of 44 consecutive cases

2014 ◽  
Vol 05 (04) ◽  
pp. 349-354 ◽  
Author(s):  
Mark A. Rivkin ◽  
Jessica F. Okun ◽  
Steven S. Yocom
Keyword(s):  
Pedicle Screw ◽  
Thoracic Spine ◽  
Pedicle Screws ◽  
High Rate ◽  
Imaging Modalities ◽  
Neurological Deficits ◽  
Upper Thoracic Spine ◽  
Starting Point ◽  
Grade 3 ◽  
Upper Thoracic

ABSTRACT Summary of Background Data: Multilevel posterior cervical instrumented fusions are becoming more prevalent in current practice. Biomechanical characteristics of the cervicothoracic junction may necessitate extending the construct to upper thoracic segments. However, fixation in upper thoracic spine can be technically demanding owing to transitional anatomy while suboptimal placement facilitates vascular and neurologic complications. Thoracic instrumentation methods include free-hand, fluoroscopic guidance, and CT-based image guidance. However, fluoroscopy of upper thoracic spine is challenging secondary to vertebral geometry and patient positioning, while image-guided systems present substantial financial commitment and are not readily available at most centers. Additionally, imaging modalities increase radiation exposure to the patient and surgeon while potentially lengthening surgical time. Materials and Methods: Retrospective review of 44 consecutive patients undergoing a cervicothoracic fusion by a single surgeon using the novel free-hand T1 pedicle screw technique between June 2009 and November 2012. A starting point medial and cephalad to classic entry as well as new trajectory were utilized. No imaging modalities were employed during screw insertion. Postoperative CT scans were obtained on day 1. Screw accuracy was independently evaluated according to the Heary classification. Results: In total, 87 pedicle screws placed were at T1. Grade 1 placement occurred in 72 (82.8%) screws, Grade 2 in 4 (4.6%) screws and Grade 3 in 9 (10.3%) screws. All Grade 2 and 3 breaches were <2 mm except one Grade 3 screw breaching 2-4 mm laterally. Only two screws (2.3%) were noted to be Grade 4, both breaching medially by less than 2 mm. No new neurological deficits or returns to operating room took place postoperatively. Conclusions: This modification of the traditional starting point and trajectory at T1 is safe and effective. It attenuates additional bone removal or imaging modalities while maintaining a high rate of successful screw placement compared to historical controls.

Biomechanical Comparison of Costotransverse Process Screw Fixation and Pedicle Screw Fixation of the Upper Thoracic Spine

2010 ◽  
Vol 66 (suppl_1) ◽  
pp. ons-178-ons-182
Author(s):  
Andrew S. Little ◽  
Leonardo B.C. Brasiliense ◽  
Bruno C.R. Lazaro ◽  
Phillip M. Reyes ◽  
Curtis A. Dickman ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Pedicle Screw ◽  
Thoracic Spine ◽  
Screw Fixation ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Lateral Bending ◽  
Upper Thoracic Spine ◽  
Pull Out ◽  
Upper Thoracic

Abstract Objective: To compare the biomechanics of costotransverse process screw fixation with those of pedicle screw fixation in a cadaveric model of the upper thoracic spine. Methods: Ten human thoracic spines were instrumented across the T3–T4 segment with costotransverse and pedicle screws. Nonconstraining pure moments (maximum, 6.0 Nm) were applied to induce flexion, extension, lateral bending, and axial rotation. The range of motion, lax zone, and stiff zone were determined in each specimen in the normal state, after 3-column destabilization, and after instrumentation. After flexibility testing was completed, axial screw pull-out strength was assessed. Results: In all directions of loading, both fixation techniques significantly decreased lax zone and range of motion at T3–T4 compared with the destabilized state (P &lt; .001). During all loading modes except lateral bending, pedicle screw fixation allowed significantly less range of motion than costotransverse screw fixation. Pedicle screws provided 62% greater resistance to axial pull-out than costotransverse screws. Conclusion: The costotransverse screw technique seems to provide only moderately stiff fixation of the destabilized thoracic spine. Pedicle screw fixation seems to have more favorable biomechanical properties. These data suggest that the costotransverse process construct is better used as a salvage procedure rather than as a primary fixation strategy.

Translaminar screw fixation in the upper thoracic spine

2006 ◽  
Vol 5 (6) ◽  
pp. 527-533 ◽  
Author(s):  
Ryan M. Kretzer ◽  
Daniel M. Sciubba ◽  
Carlos A. Bagley ◽  
Jean-Paul Wolinsky ◽  
Ziya L. Gokaslan ◽  
...  
Keyword(s):  
Thoracic Spine ◽  
Pedicle Screws ◽  
Attractive Alternative ◽  
Rigid Fixation ◽  
Upper Thoracic Spine ◽  
Pull Out ◽  
Translaminar Screw ◽  
Upper Thoracic ◽  
Translaminar Screws

Object The use of pedicle screws (PSs) for instrument-assisted fusion in the cervical and thoracic spine has increased in recent years, allowing smaller constructs with improved biomechanical stability and repositioning possibilities. In the smaller pedicles of the upper thoracic spine, the placement of PSs can be challenging and may increase the risk of damage to neural structures. As an alternative to PSs, translaminar screws can provide spinal stability, and they may be used when pedicular anatomy precludes successful placement of PSs. The authors describe the technique of translaminar screw placement in the T-1 and T-2 vertebrae. Methods Seven patients underwent cervicothoracic fusion to treat trauma, neoplasm, or degenerative disease. Nineteen translaminar screws were placed, 13 at T-1 and six at T-2. A single asymptomatic T-2 screw violated the ventral laminar cortex and was removed. The mean clinical and radiographic follow up exceeded 14 months, at which time there were no cases of screw pull-out, screw fracture, or progressive kyphotic deformity. Conclusions Rigid fixation with translaminar screws offers an attractive alternative to PS fixation, allowing the creation of sound spinal constructs and minimizing potential neurological morbidity. Their use requires intact posterior elements, and care should be taken to avoid violation of the ventral laminar wall.

scholarly journals Free-hand placement of high thoracic pedicle screws with the aid of fluoroscopy: evaluation of positioning by CT scans in a four-year consecutive series

2010 ◽  
Vol 68 (3) ◽  
pp. 390-395 ◽  
Author(s):  
Bruno Perocco Braga ◽  
Josaphat Vilela de Morais ◽  
Marcelo Duarte Vilela
Keyword(s):  
Thoracic Spine ◽  
Pedicle Screws ◽  
Ct Scans ◽  
Screw Placement ◽  
Consecutive Series ◽  
Upper Thoracic Spine ◽  
Hardware Failure ◽  
Thoracic Pedicle Screws ◽  
Upper Thoracic ◽  
Technical Principles

OBJECTIVE: To evaluate the feasibility, safety and accuracy of pedicle screw placement in the upper thoracic spine using the free-hand technique with the aid of fluoroscopy; to analyze the methods used to verify correct screw positioning intra and postoperatively. METHOD: All patients with instability of the cervicothoracic or upper thoracic spine and at least one screw placed in the segment T1-T6 as part of a posterior construct entered the study. Only C-arm intraoperative fluoroscopy was used to guide screw placement. RESULTS: We obtained excellent positioning in 98.07% of the screws. CT scans precisely demonstrated pedicle wall and anterolateral body violations. There was no hardware failure, no neurological or vascular injury and no loss of alignment during the follow-up period. CONCLUSION: Pedicle screws can be safely placed in the upper thoracic spine when strict technical principles are followed. Only a CT scan can precisely demonstrate vertebral body and medial pedicle cortical violations.

Multiple Fractures of the Cervical and Upper Thoracic Spine without Neurological Deficit: Case Report

Neurosurgery ◽  
1989 ◽  
Vol 24 (5) ◽  
pp. 768-771
Author(s):  
George R. Cybulski ◽  
James L. Stone ◽  
Paul M. Arnold ◽  
Justo Rodriguez ◽  
Sankar Banerjee
Keyword(s):  
Case Report ◽  
Thoracic Spine ◽  
Neurological Deficit ◽  
Cervical Vertebrae ◽  
Spinal Instability ◽  
Thoracic Vertebrae ◽  
Multiple Fractures ◽  
Upper Thoracic Spine ◽  
Upper Thoracic

ABSTRACT The case of a patient with multiple contiguous fractures of the cervical and upper thoracic spine without neurological deficit or spinal instability is presented. Injury to each of the cervical vertebrae plus the upper two thoracic vertebrae is unusual and has not been previously reported.

scholarly journals Accuracy Assessment of Pedicle and Lateral Mass Screw Insertion Assisted by Customized 3D-Printed Drill Guides: A Human Cadaver Study

2018 ◽  
Vol 16 (1) ◽  
pp. 94-102 ◽  
Author(s):  
Peter A J Pijpker ◽  
Joep Kraeima ◽  
Max J H Witjes ◽  
D L Marinus Oterdoom ◽  
Maarten H Coppes ◽  
...  
Keyword(s):  
Thoracic Spine ◽  
Patient Specific ◽  
Lateral Mass ◽  
Lateral Mass Screw ◽  
Upper Thoracic Spine ◽  
Screw Insertion ◽  
Drill Guide ◽  
Entry Points ◽  
3D Printed ◽  
Upper Thoracic

Abstract BACKGROUND Accurate cervical screw insertion is of paramount importance considering the risk of damage to adjacent vital structures. Recent research in 3-dimensional (3D) technology describes the advantage of patient-specific drill guides for accurate screw positioning, but consensus about the optimal guide design and the accuracy is lacking. OBJECTIVE To find the optimal design and to evaluate the accuracy of individualized 3D-printed drill guides for lateral mass and pedicle screw placement in the cervical and upper thoracic spine. METHODS Five Thiel-embalmed human cadavers were used for individualized drill-guide planning of 86 screw trajectories in the cervical and upper thoracic spine. Using 3D bone models reconstructed from acquired computed tomography scans, the drill guides were produced for both pedicle and lateral mass screw trajectories. During the study, the initial minimalistic design was refined, resulting in the advanced guide design. Screw trajectories were drilled and the realized trajectories were compared to the planned trajectories using 3D deviation analysis. RESULTS The overall entry point and 3D angular accuracy were 0.76 ± 0.52 mm and 3.22 ± 2.34°, respectively. Average measurements for the minimalistic guides were 1.20 mm for entry points, 5.61° for the 3D angulation, 2.38° for the 2D axial angulation, and 4.80° for the 2D sagittal angulation. For the advanced guides, the respective measurements were 0.66 mm, 2.72°, 1.26°, and 2.12°, respectively. CONCLUSION The study ultimately resulted in an advanced guide design including caudally positioned hooks, crosslink support structure, and metal inlays. The novel advanced drill guide design yields excellent drilling accuracy.

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