Biomechanical comparison of the pullout strengths of C1 lateral mass screws and C1 posterior arch screws

Zarro, Christopher; Ludwig, Steven C.; Hsieh, Adam H.; Seal, Charles; Gelb, Daniel E.

doi:10.1016/j.spinee.2013.06.015

Cited by 41 publications

(29 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The C-1 LMS is a common method for C-1 fixation but it is technically demanding, especially when the lateral mass is obscured by a thick posterior arch, 39 ponticulus posticus, 17 anomalous VA, 17,28,35,37 or a large paravertebral venous plexus. 21 Goel et al reported 2 patients who required an alternative method and only 1-side LMS was completed in 9 cases.…”

Section: Discussionmentioning

confidence: 99%

“…It has been shown that a unicortical C-1 PS was stiffer than a unicortical C-1 LMS. 7,21,39 However, it has been shown that 7.5% of C-1 pedicles were less than 3.5 mm 3 , which means they were not suitable for PS placement. Thirteen percent of C-1s with ponticulus posticus may give the false appearance of a pedicle and pose a considerable risk.…”

Section: 4mentioning

confidence: 99%

“…7,21,39 If C1-2 was displaced after injury, the PS may exhibit stronger resistance. It was also shown that the incidence of a VA anomaly between C-1 and C-2 in Asia was more common than in the US, and it directly affected the safety of C-1 LMS placement, 17,28,35,37 so fixation must be planned to minimize the VA injury.…”

Section: 4mentioning

confidence: 99%

See 2 more Smart Citations

Unilateral C-1 posterior arch screws and C-2 laminar screws combined with a 1-side C1–2 pedicle screw system as salvage fixation for atlantoaxial instability

Jin

Wang

2016

SPI

View full text Add to dashboard Cite

OBJECT Atlantoaxial instability often requires surgery, and the current methods for fixation pose some risk to vascular and neurological tissues. Thus, new effective and safer methods are needed for salvage operations. This study sought to assess unilateral C-1 posterior arch screws (PASs) and C-2 laminar screws (LSs) combined with 1-side C1–2 pedicle screws (PSs) for posterior C1–2 fixation using biomechanical testing with bilateral C1–2 PSs in a cadaveric model. METHODS Six fresh ligamentous human cervical spines were evaluated for their biomechanics. The cadaveric specimens were tested in their intact condition, stabilization after injury, and after injury at 1.5 Nm of pure moment in 6 directions. The 3 groups tested were bilateral C1–2 PSs (Group A); left side C1–2 PSs with an ipsilateral C-1 PAS + C-2 laminar screw (Group B); and left side C1–2 PSs with a contralateral C-1 PAS + C-2 LS (Group C). During the testing, angular motion was measured using a motion capture platform. Data were recorded, and statistical analyses were performed. RESULTS Biomechanical testing showed that there was no significant difference among the stabilities of these fixation systems in flexion-extension and rotation control. In left lateral bending, the bilateral C1–2 PS group decreased flexibility by 71.9% compared with the intact condition, the unilateral C1–2 PS and ipsilateral PAS+LS group decreased flexibility by 77.6%, and the unilateral C1–2 PS and contralateral PAS+LS group by 70.0%. Each method significantly decreased C1–2 movements in right lateral bending compared with the intact condition, and the bilateral C1–2 PS system was more stable than the C1–2 PS and contralateral PAS+LS system (p = 0.036). CONCLUSIONS A unilateral C-1 PAS + C-2 LS combined with 1-side C-1 PSs provided the same acute stability as the PS, and no statistically significant difference in acute stability was found between the 2 screw techniques. These methods may constitute an alternative method for posterior atlantoaxial fixation.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: 4mentioning

confidence: 99%

See 1 more Smart Citation

Unilateral C-1 posterior arch screws and C-2 laminar screws combined with a 1-side C1–2 pedicle screw system as salvage fixation for atlantoaxial instability

Jin

Wang

2016

SPI

View full text Add to dashboard Cite

show abstract

“…Compared with transarticular screws, C 1 lateral mass-C 2 pedicle screw fixation and C 1 -C 2 pedicle screw fixation show effective intraoperative reduction and decrease the risk of vertebral artery injury. In addition, several studies found that C 1 -C 2 pedicle screw fixation with more cortical purchase and a longer screw trajectory had higher biomechanical stiffness than C 1 lateral mass-C 2 pedicle screw fixation [8,9]. However, there were few studies analyzing cervical ROM in children after atlantoaxial fusion.…”

Section: Discussionmentioning

confidence: 99%

“…Ma et al [8] showed that the biomechanical stability of unicortical C 1 pedicle screws parallels the bicortical C 1 lateral mass screws. Zarro et al [9] found that unicortical C 1 pedicle screw fixation has higher pullout strengths than with the unicortical C 1 lateral mass screw. Because of the superior biomechanical stiffness of C 1 pedicle screw fixation, short segment C 1 -C 2 fixation assures stability of reduction and maintains cervical ROM as much as possible.…”

Section: Introductionmentioning

confidence: 99%

In vivo Analysis of Cervical Range of Motion after Revised C<sub>1</sub>-C<sub>2</sub> Pedicle Screw Technique for Pediatric Atlantoaxial Instability

Yang

Li²,

Tan³

et al. 2013

Pediatr Neurosurg

View full text Add to dashboard Cite

Objective: The purpose of this study was to analyze the cervical range of motion (ROM) after revised C₁-C₂ pedicle screw fixation for pediatric patients with atlantoaxial instability. Methods: 17 pediatric patients (age range 5-14 years; mean 8.3 years) underwent the revised C₁-C₂ pedicle screw technique. Pre- and postoperative cervical ROM during flexion/extension, rotation and lateral bending were measured using a head-mounted motion goniometer. Plain radiographs, CT scans and MRI were performed to assess spinal cord compression, the accuracy of screw placement, and bone fusion. The American Spinal Injury Association classification was used to evaluate neurological function. Results: Revised atlantoaxial pedicle screw fixation was successfully performed in all 17 pediatric patients. There were no perioperative complications. All cases showed evidence of bone fusion 6 months after surgery by CT scan. During the follow-up period (24-92 months), of 6 patients with preoperative myelopathy, 3 improved from grade D to grade E and 3 from grade C to grade D. The final follow-up cervical ROM was significantly greater than the preoperative and 6-month postoperative ROM. There was a statistically significant difference between preoperative and 6-month postoperative ROM for flexion, extension, and left and right axial rotation movements. Conclusion: As a short-segmental fixation technique, revised C₁-C₂ pedicle screw fixation can provide effective biomechanical stability. Final follow-up cervical ROM is significantly increased through alleviating cervical pain and symptoms of myelopathy after surgery and possible subaxial compensation.

show abstract

Surgical Management of Chordoma of the Occipitocervical Junction

Pennington

Ehresman

Schilling

et al. 2021

Chordoma of the Spine

View full text Add to dashboard Cite

Biomechanical comparison of the pullout strengths of C1 lateral mass screws and C1 posterior arch screws

Cited by 41 publications

References 18 publications

Unilateral C-1 posterior arch screws and C-2 laminar screws combined with a 1-side C1–2 pedicle screw system as salvage fixation for atlantoaxial instability

Unilateral C-1 posterior arch screws and C-2 laminar screws combined with a 1-side C1–2 pedicle screw system as salvage fixation for atlantoaxial instability

In vivo Analysis of Cervical Range of Motion after Revised C<sub>1</sub>-C<sub>2</sub> Pedicle Screw Technique for Pediatric Atlantoaxial Instability

Surgical Management of Chordoma of the Occipitocervical Junction

Contact Info

Product

Resources

About