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Mallepally AR, Marathe N, Menon S, Das K. Misplaced S1 screw causing L5 radiculopathy, rare and unusual presentation: a report of 2 cases. Br J Neurosurg 2024; 38:131-135. [PMID: 34396884 DOI: 10.1080/02688697.2021.1967286] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 08/09/2021] [Indexed: 10/20/2022]
Abstract
Many spine surgeons are not optimally acquainted with anatomy anterior to sacrum. Screw malposition injuring these structures can lead to unwanted lethal consequences. We report unusual cases of acute radiculopathy due to misplaced bicortical sacral screw causing L5 nerve root impingement on anterior sacrum. A 39/M patient complained of severe rest pain (VAS 9/10) post TLIF in region of L5 dermatome with sensory deficit along the right lateral leg and straight leg raise less than 30°. X-ray revealed S1 screw protruding beyond the second cortex with a straight trajectory. CT scan revealed a protrusion of 11.4mm beyond anterior cortex. The patient was taken for re-surgery and the trajectory and length of screw was revised. Sciatic pain completely disappeared immediately after surgery. A 61/M patient operated elsewhere with instrumented decompression and fusion with screws passed at L4, L5 and S1 level for lumbar canal stenosis, post-surgery patient developed new onset radicular symptoms in right lower limb. Patient was managed conservatively in the form of L5 selective nerve root block. Pain and numbness improved. Bicortical purchase of S1 screw though improves pull out strength, is associated with a risk of neurovascular complications. Surgeons should be alerted to the misplacement of S1 pedicle screws to avoid involvement not only anterior to the anteromedial neurovascular tissue, but also anterolateral to the arrangement of the L5 nerve root.
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Affiliation(s)
| | - Nandan Marathe
- Department of spine services, Indian Spinal Injuries Centre, New Delhi, India
| | - Sreejith Menon
- Department of spine services, Indian Spinal Injuries Centre, New Delhi, India
| | - Kalidutta Das
- Department of spine services, Indian Spinal Injuries Centre, New Delhi, India
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Tamagawa S, Okuda T, Nojiri H, Sato T, Momomura R, Ohara Y, Hara T, Ishijima M. Anatomy of the L5 nerve root in the pelvis for safe sacral screw placement: a cadaveric study. J Neurosurg Spine 2022; 36:809-814. [PMID: 34798616 DOI: 10.3171/2021.8.spine21962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/09/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Previous reports have focused on the complications of L5 nerve root injury caused by anterolateral misplacement of the S1 pedicle screws. Anatomical knowledge of the L5 nerve root in the pelvis is essential for safe and effective placement of the sacral screw. This cadaveric study aimed to investigate the course of the L5 nerve root in the pelvis and to clarify a safe zone for inserting the sacral screw. METHODS Fifty-four L5 nerve roots located bilaterally in 27 formalin-fixed cadavers were studied. The ventral rami of the L5 nerve roots were dissected along their courses from the intervertebral foramina to the lesser pelvis. The running angles of the L5 nerve roots from the centerline were measured in the coronal plane. In addition, the distances from the ala of the sacrum to the L5 nerve roots were measured in the sagittal plane. RESULTS The authors found that the running angles of the L5 nerve roots changed at the most anterior surface of the ala of the sacrum. The angles of the bilateral L5 nerve roots from the right and left L5 intervertebral foramina to their inflection points were 13.77° ± 5.01° and 14.65° ± 4.71°, respectively. The angles of the bilateral L5 nerve roots from the right and left inflection points to the lesser pelvis were 19.66° ± 6.40° and 20.58° ± 5.78°, respectively. There were no significant differences between the angles measured in the right and left nerve roots. The majority of the L5 nerves coursed outward after changing their angles at the inflection point. The distances from the ala of the sacrum to the L5 nerve roots in the sagittal plane were less than 1 mm in all cases, which indicated that the L5 nerve roots were positioned close to the ala of the sacrum and had poor mobility. CONCLUSIONS All of the L5 nerve roots coursed outward after exiting the intervertebral foramina and never inward. To prevent iatrogenic L5 nerve root injury, surgeons should insert the S1 pedicle screw medially with an angle > 0° toward the inside of the S1 anterior foramina and the sacral alar screw laterally with an angle > 30°.
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Affiliation(s)
- Shota Tamagawa
- 1Department of Orthopedic Surgery, Juntendo University School of Medicine, Tokyo
| | - Takatoshi Okuda
- 1Department of Orthopedic Surgery, Juntendo University School of Medicine, Tokyo
| | - Hidetoshi Nojiri
- 1Department of Orthopedic Surgery, Juntendo University School of Medicine, Tokyo
| | - Tatsuya Sato
- 1Department of Orthopedic Surgery, Juntendo University School of Medicine, Tokyo
| | - Rei Momomura
- 2Department of Orthopedic Surgery, Juntendo University Urayasu Hospital, Chiba; and
| | - Yukoh Ohara
- 3Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
| | - Takeshi Hara
- 3Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
| | - Muneaki Ishijima
- 1Department of Orthopedic Surgery, Juntendo University School of Medicine, Tokyo
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Tamagawa S, Okuda T, Nojiri H, Momomura R, Ishijima M. L5 nerve root injury caused by anterolateral malpositioning of loosened S1 pedicle screws: illustrative cases. JOURNAL OF NEUROSURGERY: CASE LESSONS 2021; 1:CASE21207. [PMID: 35855081 PMCID: PMC9245777 DOI: 10.3171/case21207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 04/20/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Although malpositioning of pedicle screws into the spinal canal and intervertebral foramen can cause spinal nerve root injuries, there are few reports of L5 nerve root injuries when S1 pedicle screws have been inserted anterolaterally. The authors report two cases of L5 nerve root injury caused by anterolateral malpositioning of loosened S1 pedicle screws. OBSERVATIONS In both patients, S1 pedicle screws were inserted toward the outside of the S1 anterior foramen, and the tip of the screws perforated the anterior sacral cortex. L5 nerve root impairment was not observed immediately after surgery. However, severe leg pain in the L5 area was observed after the S1 pedicle screws became loosened. In case 1, the symptoms could not be controlled with conservative treatment. Reoperation was performed 3 months after the initial surgery. In case 2, the symptoms gradually improved with conservative treatment because the area around the loosened S1 screw was surrounded by newly formed bone that stabilized the screws, as observed with computed tomography 1 year after surgery. LESSONS Surgeons should recognize that anterolateral malpositioning of S1 pedicle screws can cause L5 nerve root injury. The screws should be inserted in the correct direction without loosening.
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Affiliation(s)
- Shota Tamagawa
- Department of Orthopedic Surgery, Juntendo University School of Medicine, Tokyo, Japan; and
| | - Takatoshi Okuda
- Department of Orthopedic Surgery, Juntendo University School of Medicine, Tokyo, Japan; and
| | - Hidetoshi Nojiri
- Department of Orthopedic Surgery, Juntendo University School of Medicine, Tokyo, Japan; and
| | - Rei Momomura
- Department of Orthopedic Surgery, Juntendo University Urayasu Hospital, Chiba, Japan
| | - Muneaki Ishijima
- Department of Orthopedic Surgery, Juntendo University School of Medicine, Tokyo, Japan; and
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Sahu S, Yadav R, Sudhan MD, Rao A, Mohimen A. Spinal Pedicle Morphometry using Multidetector CT—An experience from the Indian Subcontinent. INDIAN JOURNAL OF NEUROSURGERY 2021. [DOI: 10.1055/s-0040-1719203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Abstract
Introduction For safe pedicle screws placement, knowledge of pedicle morphometry is essential, because an inconsistency between pedicle width and the screw diameter may lead to severe complications like nerve, vessel or visceral injuries.
Objectives To study the spinal pedicle width and height of lumbar spine, using multidetector CT (MDCT), among the Indian population. To study the spinal pedicle angulation of lumbar spine, using MDCT, among the Indian population.
Method The study was conducted at a tertiary care multispecialty hospital. In the present study, a total of 321 patients were included, who underwent MDCT scan without contrast at our institution, over a period of 2 years, from May 2017 to May 2019. The study population (n = 321) was divided into different subgroups on the basis of the age. The data was taken from the workstation. Comparison was made separately between each subgroup.
Results In our subset of population, the 10 to 90 years age group, pedicle dimensions are as follow: The pedicle diameter from L1 to L5 is 4.46 to 11.92 mm. The pedicle height from L1 to L5 is 7.38 to 11.01 mm. The pedicle axial angulation from L1 to L5 is 22.27 to 36.08 degree. The pedicle lateral angulation from L1 to L5 is 16.12 to 22.47 degree.
Conclusion Knowledge of the pedicle morphometry (pedicle width, height and angulation) of lumbar spine will help the neurosurgeons standardize the size of pedicle screws which is required for spinal fixation surgery at various lumbar vertebra levels.
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Affiliation(s)
- Samaresh Sahu
- Department of Radiodiagnosis & Imaging, Armed Forces Medical College, Pune, India
| | - Ravinder Yadav
- Department of Imaging & Interventional Radiology, Command Hospital Air Force, Agram Post, Bengaluru, India
| | - Manoharan D. Sudhan
- Department of Neurosurgery, Indian Naval Hospital Ship Asvini, Colaba, Mumbai, India
| | - Akhilesk Rao
- Department of Imaging & Interventional Radiology, Command Hospital Air Force, Agram Post, Bengaluru, India
| | - Aneesh Mohimen
- Department of Imaging & Interventional Radiology, Command Hospital Air Force, Agram Post, Bengaluru, India
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Becker L, Schömig F, Haffer H, Ziegeler K, Diekhoff T, Pumberger M. Safe Zones for Spinopelvic Screws in Patients With Lumbosacral Transitional Vertebra. Global Spine J 2021; 13:1089-1096. [PMID: 34044627 DOI: 10.1177/21925682211019354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
STUDY DESIGN Retrospective matched-pair analysis. OBJECTIVES Lumbosacral transitional vertebrae (LSTV) have a reported prevalence of 4-36% in the population. The safe zones for screw placement for spinopelvic fusion in adult spinal deformity surgery for patients with LSTV have not been described in the literature. Our study aimed to assess the safety of S1-pedicle screw (S1PS), S2-alar screw (S2AS), S2-alar-iliac screw (S2AIS), and iliac screw (IS) placement in patients with LSTV. METHODS Out of the 819 examined patients, 49 patients with LSTV were included in our retrospective analysis with a matched pair control group. We used the 3-dimensional planning tool mediCAD for screw placement of S1PS, S2AS, S2AIS, IS with different angles, length and diameters. RESULTS We evaluated a total of 10 192 screw trajectories. No serious complications occurred due to the trajectories used for S1PS. LSTV increased the risk of vessel injury for S2AS trajectories (P = .001) but not for S2AIS (P = .526). Besides the presence of an LSTV, the screw trajectory had a major influence on the frequency of serious complications. CONCLUSIONS Sacral anchoring of long spinal constructions using S1PS, S2AS, S2AIS and IS is also possible in the presence of LSTV. For S2AS the trajectory with 30° lateral and caudal angulation of 10° showed the least vascular injuries and the least sacro-iliac-joint violations in patients with LSTV. S2AIS trajectories with 40° lateral and 0° sagittal angulation reduced the risk of serious complications in our patients collective with LSTV.
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Affiliation(s)
- Luis Becker
- Center for Musculoskeletal Surgery, Charité-University Medicine Berlin, Charitéplatz, Berlin, Germany
| | - Friederike Schömig
- Center for Musculoskeletal Surgery, Charité-University Medicine Berlin, Charitéplatz, Berlin, Germany
| | - Henryk Haffer
- Center for Musculoskeletal Surgery, Charité-University Medicine Berlin, Charitéplatz, Berlin, Germany
| | - Katharina Ziegeler
- Department of Radiology, Charité-University Medicine Berlin, Charitéplatz, Berlin, Germany
| | - Torsten Diekhoff
- Department of Radiology, Charité-University Medicine Berlin, Charitéplatz, Berlin, Germany
| | - Matthias Pumberger
- Center for Musculoskeletal Surgery, Charité-University Medicine Berlin, Charitéplatz, Berlin, Germany
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Dalbayrak S, Öğrenci A, Akar E, Koban O, Yılmaz M. A Novel Placement Technique of S2 Screw (from S2 to Promontorium) and Double Screwing from S2. INDIAN JOURNAL OF NEUROSURGERY 2021. [DOI: 10.1055/s-0041-1728987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
AbstractSince pseudoarthrosis or screw loosening is frequently seen in lumbosacral stabilizations ending in S1, S2 screws are used more frequently to support S1 screws. This study aims to describe a new screw placement technique and location from S2. Revision surgery was applied to the patient who had previously undergone surgery with the rigid instrumentation system and encountered pseudoarthrosis during the follow-up period. Instrumentation was performed from S2 to the promontorium. The patient’s chronic low back pain arising due to pseudoarthrosis was reduced and a strong lumbosacral dynamic instrumentation was performed to the patient. Dual screw placement from S2 and/or screw placement in the S2-promontorium direction is a new alternative to provide a powerful instrumentation.
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Affiliation(s)
- Sedat Dalbayrak
- Department of Neurosurgery, Okan University, Istanbul, Turkey
| | - Ahmet Öğrenci
- Department of Neurosurgery, Okan University, Istanbul, Turkey
| | - Ezgi Akar
- Department of Neurosurgery, Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey
| | - Orkun Koban
- Department of Neurosurgery, Okan University, Istanbul, Turkey
| | - Mesut Yılmaz
- Department of Neurosurgery, Neurospinal Academia, Istanbul, Turkey
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Bagheri H, Govsa F. Anatomical considerations of safe drilling corridor upper sacral segment screw insertion. J Orthop 2019; 16:543-551. [PMID: 31660021 PMCID: PMC6806658 DOI: 10.1016/j.jor.2019.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 04/15/2019] [Indexed: 10/26/2022] Open
Abstract
The upper segment of sacrum is an important for screw insertions of unstable lumbosacral spine. Measurements of the S1-S2 as sacral wings, pedicles, sacral foraminas and sacral canal were taken from 87 sacrums. The mean depths of S1 pedicle and sacral wing were estimated as 25.8 ± 2.3 mm and 50.1 ± 1.7 mm, respectively. Angles screw trajectory of sacral pedicle anteromedial and sacral wing were measured as 29.6 ± 0.9° and 29.7 ± 2.1°, respectively. To avoid injury to the vascular structures anteriorly and nerve roots medially, depth and angle of screw trajectory is important for the entrance off pedicular screw placement to the S1.
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Affiliation(s)
| | - Figen Govsa
- Department of Anatomy Digital Imaging and 3D Modelling Laboratory, Faculty of Medicine, Ege University, Izmir, Turkey
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Intraoperative Radiographic Technique for Visualization of Bicortical or Tricortical Anteromedial Sacral Screw Placement. Clin Spine Surg 2018. [PMID: 28650881 DOI: 10.1097/bsd.0000000000000561] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The bicortical anteromedial sacral screw trajectory is the most widely used for S1 screw fixation. The assessment of anterior cortex purchase is difficult on a lateral view due to the overlapping bony anatomy of the sacrum and pelvis. We describe the intraoperative radiographic technique for a personalized pelvic inlet view that is perpendicular to the superior sacral surface to visualize sacral screw placement. This technique allows for assessment of anterior cortex purchase with anteromedial angulation in the same view.
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Kubaszewski L, Nowakowski A, Kaczmarczyk J. Evidence-based support for S1 transpedicular screw entry point modification. J Orthop Surg Res 2014; 9:22. [PMID: 24708681 PMCID: PMC4016646 DOI: 10.1186/1749-799x-9-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 03/19/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the literature, 'below and lateral to the superior S1 facet' is defined as the basic technique for screw introduction. Until a recently published modification, no analysis for alternative starting point has been proposed nor evaluated, although some surgeons claim to use some modifications. In this study, we analyse the data from anatomical and radiological studies for optimal starting point in transpedicular S1 screw placement. METHODS A Medline search for key word combination: sacrum, anatomy, pedicle, screws and bone density resulted in 26 publications relevant to the topic. After a review of literature, two articles were chosen, as those including the appropriate set of data. The data retrieved from the articles is used for the analysis. The spatial relation of S1 facet, pedicles and vertebral body with cortical thickness and bone density in normal, osteopenic and osteoporotic sacrum is analysed. RESULTS Presented data advocates for more medial placement of the screws due to higher bone density and lower bone loss in osteoporosis. Medial shift of the starting point does not increase the risk of spinal canal perforation. Osteoarthritic changes within the facet can augment the posterior supporting point for screw. The facet angular orientation is similar to convergent screw trajectory. CONCLUSIONS Modified technique for S1 screw placement takes advantage of latest anatomical and clinical data. In our opinion, technique modification improves the reproducibility and may increase stability and the screws within the posterior cortex of the S1 vertebra. Further biomechanical and clinical study should be performed to prove its superiority to classical technique.
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Affiliation(s)
- Lukasz Kubaszewski
- Department of Orthopaedic and Traumatology, W, Dega University Hospital, University of Medical Science Poznan, 28 Czerwca 1956 r Street, Poznań 61-545, Poland.
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Reinforcement of lumbosacral instrumentation using S1–pedicle screws combined with S2–alar screws. OPERATIVE ORTHOPADIE UND TRAUMATOLOGIE 2013; 25:294-314. [DOI: 10.1007/s00064-012-0160-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Inoue M, Inoue G, Ozawa T, Miyagi M, Kamoda H, Ishikawa T, Suzuki M, Sakuma Y, Oikawa Y, Yamauchi K, Orita S, Takaso M, Toyone T, Takahashi K, Ohtori S. L5 spinal nerve injury caused by misplacement of outwardly-inserted S1 pedicle screws. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2012; 22 Suppl 3:S461-5. [PMID: 23269529 DOI: 10.1007/s00586-012-2634-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Revised: 12/05/2012] [Accepted: 12/16/2012] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate L5 nerve root injuries caused by outwardly misplaced S1 pedicle screws. Pedicle screws remain the criterion standard for fixation of L5-S1 to correct lumbosacral instability. When inserting S1 pedicle screws, it is possible to injure the L5 nerve root if screws are inserted outwardly and the tip of the screw perforates the anterior cortex of the sacrum. Despite this risk, to our knowledge this type of injury has never been reported as a case series. METHODS We experienced 2 cases of L5 nerve root injury caused by outwardly-inserted S1 pedicle screws. In both cases, bilateral S1 pedicle screws were inserted outwardly using a free-hand technique, and on one side, screws induced severe pain by impinging on an L5 root. Computed tomography after the selective rootgraphy of the injured nerve showed the nerve compressed laterally by screw threads in Case 1 and crushed between the screw threads and the sacral body in Case 2. RESULTS In both cases, leg pain disappeared immediately after the infiltration of the nerve with lidocaine, but symptoms recurred within a few days in Case 1 and within an hour in Case 2. Conservative treatment of three spinal nerve infiltrations was effective in Case 1, but reinsertion of the rogue screw was necessary in Case 2. CONCLUSIONS Surgeons should recognize that lateral inclination of S1 pedicle screws can cause L5 nerve root injury, which may require reinsertion of the screw, especially in cases where insertion is difficult because of overlapping surrounding muscle or bony tissue.
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Affiliation(s)
- Masahiro Inoue
- Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan
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The human sacrum and safe approaches for screw placement. J Clin Neurosci 2009; 16:1046-9. [PMID: 19442524 DOI: 10.1016/j.jocn.2008.07.081] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 07/22/2008] [Accepted: 07/24/2008] [Indexed: 11/22/2022]
Abstract
The human sacrum is the target of lumbosacral instrumentation and decompression procedures. Such surgical interventions require detailed knowledge of the anatomy of the human sacrum. The aim of this study was to measure surgically relevant parameters. Several factors, including the one-piece composition of the sacrum, the angles of the sacral pedicles and the anteroposterior diameter of the sacral vertebral bodies distinguish the sacrum from other parts of spine. Thirty-two measurements of shape, angles and distances between parts were taken of the sacra of 100 adult West Anatolian people using a Vernier caliper accurate to 0.1 mm and goniometer. According to this morphometric study, when measured from the sagittal, the S1 facet angle was measured as 35.71 degrees +/-9.59 and 34.70 degrees +/-9.66, the sacral pedicle anteromedial screw trajectory angle was 35.65 degrees +/-4.73 and 31.95 degrees +/-3.95 and the anterolaterally oriented sacral wing screw trajectory angle was 32.65 degrees +/-3.51 and 29.10 degrees +/-3.14, on the right and left sides, respectively. The distance of the midline oriented S1 pedicle screw was 51.12 mm and 51.26 mm on the right and left side, respectively. The distance for sacral wing oriented screw placement was 50.13 mm and 50.46 mm on the right and left side, respectively. The anteroposterior and transverse diameter of the sacral spinal canal were 21.81 mm and 31.31 mm, respectively. Thus, this study describes anatomical specifications of the sacrum. These defined morphometric details should be taken into consideration during surgical procedures. This study also describes anatomical landmarks which will allow injury of the sacrum during surgery to be avoided.
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