P157. An Anatomical Study which Describes the Relationship of the Pedicle Center to the Mid-Lateral Pars (MLP) in the Lower Lumbar Spine as a Guide to Pedicle Screw Placement

Abstract INTRODUCTION Posterior spinal instrumentation for fusion using intraoperative computed tomography (CT) navigation is gaining traction as an alternative to the conventional two-dimensional fluoroscopic-guided approach to percutaneous pedicle screw placement. However, few studies to date have directly compared outcomes of these 2 minimally invasive instrumentation methods. METHODS A consecutive cohort of patients undergoing primary percutaneous posterior lumbar spine instrumentation for spine fusion was retrospectively reviewed. Revision surgeries or cases converted to open were excluded. Accuracy of screw placement was assessed using a postoperative CT scan with blinding to the surgical methods used. The Gertzbein-Robbins classification was used to grade cortical breach: Grade 0 (<0 mm cortical breach), Grade I (<2 mm), Grade II (2-4 mm), Grade III (4-6 mm), and Grade IV (>6 mm). RESULTS CT navigation was found to significantly improve accuracy of screw placement (P < .022). There was significantly more facet violation of the unfused level in the fluoroscopy group vs the CT group (9% vs 0.5%; P < .0001). There was also a higher proportion of poor screw placement in the fluoroscopy group (10.1% vs 3.6%). No statistical difference was found in the rate of tip breach, inferomedial breach, or lateral breach. Regression analysis showed that fluoroscopy had twice the odds of incurring poor screw placement as compared to CT navigation. CONCLUSION This radiographic study comparing screw placement in minimally invasive fluoroscopy- vs CT navigation-guided lumbar spine instrumentation provides evidence that CT navigation significantly improves accuracy of screw placement, especially in optimizing the screw trajectory so as to avoid facet violation. Long-term follow-up studies should be performed to ascertain whether this difference can contribute to an improvement in clinical outcomes.

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Usefulness and radiological evaluation of accuracy of innovative “smart” hand technique for pedicle screw placement: an anatomical study

Turkish Neurosurgery ◽

10.5137/1019-5149.jtn.21391-17.1 ◽

2017 ◽

Author(s):

Ayhan Comert ◽

Ihsan Dogan ◽

Y. Sukru Caglar

Keyword(s):

Pedicle Screw ◽

Anatomical Study ◽

Screw Placement ◽

Radiological Evaluation ◽

Pedicle Screw Placement

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Confirmation of accuracy/inaccuracy of lumbar pedicle screw placement using postoperative computed tomography

Surgical Neurology International ◽

10.25259/sni_290_2021 ◽

2021 ◽

Vol 12 ◽

pp. 518

Author(s):

Mohamed M. Arnaout ◽

Magdy O. ElSheikh ◽

Mansour A. Makia

Keyword(s):

Computed Tomography ◽

Lumbar Spine ◽

Pedicle Screw ◽

Pedicle Screws ◽

Operative Intervention ◽

Screw Placement ◽

Lumbar Spine Surgery ◽

Pedicle Screw Placement ◽

Lumbar Pedicle ◽

Ct Studies

Background: Transpedicular screws are extensively utilized in lumbar spine surgery. The placement of these screws is typically guided by anatomical landmarks and intraoperative fluoroscopy. Here, we utilized 2-week postoperative computed tomography (CT) studies to confirm the accuracy/inaccuracy of lumbar pedicle screw placement in 145 patients and correlated these findings with clinical outcomes. Methods: Over 6 months, we prospectively evaluated the location of 612 pedicle screws placed in 145 patients undergoing instrumented lumbar fusions addressing diverse pathology with instability. Routine anteroposterior and lateral plain radiographs were obtained 48 h after the surgery, while CT scans were obtained at 2 postoperative weeks (i.e., ideally these should have been performed intraoperatively or within 24–48 h of surgery). Results: Of the 612 screws, minor misplacement of screws (≤2 mm) was seen in 104 patients, moderate misplacement in 34 patients (2–4 mm), and severe misplacement in 7 patients (>4 mm). Notably, all the latter 7 (4.8% of the 145) patients required repeated operative intervention. Conclusion: Transpedicular screw insertion in the lumbar spine carries the risks of pedicle medial/lateral violation that is best confirmed on CT rather than X-rays/fluoroscopy alone. Here, we additional found 7 patients (4.8%) who with severe medial/lateral pedicle breach who warranting repeated operative intervention. In the future, CT studies should be performed intraoperatively or within 24–48 h of surgery to confirm the location of pedicle screws and rule in our out medial or lateral pedicle breaches.

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Minimally Invasive, Stereotactic, Wireless, Percutaneous Pedicle Screw Placement in the Lumbar Spine: Accuracy Rates With 182 Consecutive Screws

The International Journal of Spine Surgery ◽

10.14444/5081 ◽

2018 ◽

Vol 12 (6) ◽

pp. 650-658 ◽

Cited By ~ 4

Author(s):

SAEED S. SADRAMELI ◽

RYAN JAFRANI ◽

BLAKE N. STAUB ◽

MAJDI RADAIDEH ◽

PAUL J. HOLMAN

Keyword(s):

Lumbar Spine ◽

Minimally Invasive ◽

Pedicle Screw ◽

Screw Placement ◽

Pedicle Screw Placement ◽

Percutaneous Pedicle Screw ◽

Accuracy Rates

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Percutaneous Pedicle Screw Placement in the Lumbar Spine

Journal of Spinal Disorders & Techniques ◽

10.1097/bsd.0b013e3182aab222 ◽

2015 ◽

Vol 28 (9) ◽

pp. E522-E527 ◽

Cited By ~ 9

Author(s):

Guangfei Gu ◽

Hailong Zhang ◽

Shisheng He ◽

Xiaobing Cai ◽

Xin Gu ◽

...

Keyword(s):

Lumbar Spine ◽

Pedicle Screw ◽

Screw Placement ◽

Pedicle Screw Placement ◽

Percutaneous Pedicle Screw

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Appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine using c-arm fluoroscopy: a cadaveric study

10.21203/rs.3.rs-38830/v2 ◽

2020 ◽

Author(s):

Wei-Xing Xu ◽

wei-guo Ding ◽

Bin Xu ◽

Tian-Hong Hu ◽

Hong-Feng Sheng ◽

...

Keyword(s):

Lumbar Spine ◽

Pedicle Screw ◽

Facet Joint ◽

Outer Edge ◽

Screw Placement ◽

Insertion Point ◽

Pedicle Screw Placement ◽

X Ray ◽

Articular Process ◽

Percutaneous Pedicle Screw

Abstract Background: We studied the characteristics and regularity of appropriate insertion points for percutaneous pedicle screw placement in the lumbar spine using C-arm X-ray fluoroscopy. The purpose of this study was to improve the accuracy of percutaneous pedicle screw placement and reduce the incidence of superior-level facet joint violation. Methods: Six normal spinal specimens were included. Three different methods for placing percutaneous pedicle screws in the lumbar spine were applied, including the Roy-Camille method, Magerl method and Weinstein method. The relationships among the insertion point, pedicle projection and proximal facet joint on C-arm X-ray films were studied. The projection morphology of the vertebral pedicle in different segments of the lumbar spine was observed. The relationship between the outer edge of the pedicle projection and the outer edge of the cranial articular process was also studied. The distance between the insertion point and the facet joint (M1), the distance between the insertion point and outer edge of the cranial articular process (M2), and the distance between the insertion point and the projection center of the pedicle (M) were measured. Results: In this study, we found that the projection shape of the vertebral pedicle differed across segments of the lumbar spine: the shape for L1-L3 was oval, and that for L4-L5 was round. The radiographic study showed that the outer edge of the cranial articular process was located on the lateral side of the outer edge of the pedicle projection and did not overlap with the pedicle projection. M for the Weinstein group was larger than that for the Roy-Camille group (P < 0.05). M1 for the Weinstein group was larger than that for the Roy-Camille and Magerl groups (P < 0.05). M2 for the Roy-Camille group was negative, M2 for the Magerl group was 0, and M2 for the Weinstein group was positive. Conclusion: Under C-arm X-ray fluoroscopy, we were able to accurately identify the characteristics and regularity of the appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine, which was important for improving the accuracy of percutaneous pedicle screw placement and reducing the incidence of superior-level facet joint violation.

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