Comparison of Fatigue Strength of C2 Pedicle Screws, C2 Pars Screws, and a Hybrid Construct in C1–C2 Fixation

Su, Brian W.; Shimer, Adam L.; Chinthakunta, Suresh; Salloum, Kanaan; Ames, Christopher P.; Vaccaro, Alexander R.; Bucklen, Brandon

doi:10.1097/brs.0000000000000063

Cited by 41 publications

(36 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The direction of the screw is 15 -30 medial and 20 -25 cephalad. Although a biomechanical study has shown that C2 pedicle screws have twice the pullout strength of C2 pars screws [68], the clinical results of the two fixation techniques are similar [69]. Both the C2 pedicle screw and C2 pars screw are widely used for screw-rod system fixation of C1-C2 fusion [69].…”

Section: C2 Pedicle Screw Techniquementioning

confidence: 98%

Posterior atlantoaxial fixation: a review of all techniques

et al. 2015

View full text Add to dashboard Cite

Section: C2 Pedicle Screw Techniquementioning

confidence: 98%

Posterior atlantoaxial fixation: a review of all techniques

et al. 2015

View full text Add to dashboard Cite

“…The pullout strength of a C-2 pedicle screw is greater than that of the pars. 34 In very young children, the pars may be quite small and only allow a few threads of screw purchase; therefore, a pedicle screw may be preferred if anatomically feasible. This may require threading the screw through a very narrow area.…”

Section: Discussionmentioning

confidence: 99%

“…The C-2 pars lies between the inferior and superior articular facet, whereas the pedicle connects the inferior articular facet to the vertebral body. 8,34 Both the pars and pedicle are potential targets for instrumentation. The pullout strength of a C-2 pedicle screw is greater than that of the pars.…”

Section: Discussionmentioning

confidence: 99%

Feasibility of CT-based intraoperative 3D stereotactic image-guided navigation in the upper cervical spine of children 10 years of age or younger: initial experience

Kovanda¹,

Ansari²,

Qaiser³

et al. 2015

PED

View full text Add to dashboard Cite

OBJECT Rigid screw fixation may be technically difficult in the upper cervical spine of young children. Intraoperative stereotactic navigation may potentially assist a surgeon in precise placement of screws in anatomically challenging locations. Navigation may also assist in defining abnormal anatomy. The object of this study was to evaluate the authors’ initial experience with the feasibility and accuracy of this technique, both for resection and for screw placement in the upper cervical spine in younger children. METHODS Eight consecutive pediatric patients 10 years of age or younger underwent upper cervical spine surgery aided by image-guided navigation. The demographic, surgical, and clinical data were recorded. Screw position was evaluated with either an intraoperative or immediately postoperative CT scan. RESULTS One patient underwent navigation purely for guidance of bony resection. A total of 14 navigated screws were placed in the other 7 patients, including 5 C-2 pedicle screws. All 14 screws were properly positioned, defined as the screw completely contained within the cortical bone in the expected trajectory. There were no immediate complications associated with navigation. CONCLUSIONS Image-guided navigation is feasible within the pediatric cervical spine and may be a useful surgical tool for placing screws in a patient with small, often difficult bony anatomy. The authors describe their experience with their first 8 pediatric patients who underwent navigation in cervical spine surgery. The authors highlight differences in technique compared with similar navigation in adults.

show abstract

“…pedicle screws, bilateral pars screws and hybrid of unilateral pars screw with contralateral pedicle screw combinations all showed the ability to limit range of motion and significantly decreased after cyclical testing in flexion-extension, lateral bending, and axial rotation. They concluded that in situations with anatomical limitations like a high-riding or medialized vertebral artery, the unilateral C2 pedicle screw along with a contralateral short pars screw is a viable biomechanical option that may be as stable as a bilateral pedicle screw construct (26).…”

Section: █ Conclusionmentioning

confidence: 99%

“…Ebraheim et al described the C2 pedicle as a dense bone that connects the inferior articular fascet to the C2 vertebral body, and C2 pars as a trabecular bone between superior and inferior articular processes. The distinction between these two different structures is much more significant for confrontation with situations such as a high-riding or medialized vertebral artery, in which a long C2 pedicle screw places the vertebral artery at risk (5,26).…”

Section: █ Conclusionmentioning

confidence: 99%

Can c2-pars interarticularis screw be an alternative in atlanto-axial stabilization? a biomechanical comparison of established techniques

Schleicher

Önal²,

Hemberger³

et al. 2018

Turkish Neurosurgery

View full text Add to dashboard Cite

AIM: To compare four different atlantoaxial stabilization techniques. MATERIAL and METHODS: Eight human cervical spines (segments C0-C3) were tested in flexion/extension, lateral bending and axial rotation. Range of Motion (ROM) at a 1.5 Nm load was recorded. After native testing, the Harms (HARMS), pars screw (PARS), intralaminar screw (INTRA) and anterior transarticular screw (ATA) constructs were applied in a random order. RESULTS: FLEXION/EXTENSION: mean ROM (±SD) in native state was 15.9° (± 7.6°); HARMS 3.6° (± 2.0°); INTRA 5.5° (± 2.7°); PARS 2.8° (± 1.6°); ATA 3.7° (± 1.3°). A significant difference was found for all techniques compared to the native spine. LATERAL BENDING: ROM in native state was 3.2° (± 1.9°); HARMS 1.4° (± 0.4°); INTRA 2.5° (± 1.4°); PARS 1.3° (± 0.7°); ATA 0.9° (± 0.6°). There were no significant differences compared to native spine, although ATA and PARS showed a strong tendency. INTRA had a significantly higher ROM than ATA. AXIAL ROTATION: ROM in native state was 15.7° (± 6.6°); HARMS 1.5° (± 0.7); INTRA 2.7° (± 2.1°); PARS 1.7° (± 0.7); ATA 1.1° (± 0.3°). All instrumentation techniques significantly reduced ROM; there was no significant difference between the techniques. All instrumentation techniques were able to reduce ROM for most of the motions. The differences between the techniques were small. Nevertheless, the intralaminar screw showed deficits in lateral bending. CONCLUSION: Screw positioning seems to be of minor influence on stability in atlantoaxial stabilization. Therefore, the pars screw is a sound alternative to the established techniques from a biomechanical point of view. Anatomical considerations for screw placement should be kept in mind as a superior priority.

show abstract

Comparison of Fatigue Strength of C2 Pedicle Screws, C2 Pars Screws, and a Hybrid Construct in C1–C2 Fixation

Abstract: N/A.

Cited by 41 publications

References 26 publications

Posterior atlantoaxial fixation: a review of all techniques

Posterior atlantoaxial fixation: a review of all techniques

Feasibility of CT-based intraoperative 3D stereotactic image-guided navigation in the upper cervical spine of children 10 years of age or younger: initial experience

Can c2-pars interarticularis screw be an alternative in atlanto-axial stabilization? a biomechanical comparison of established techniques

Contact Info

Product

Resources

About