scholarly journals Anatomic study of the lumbar lamina for safe and effective placement of lumbar translaminar facet screws

2019 ◽  
Vol 47 (10) ◽  
pp. 5082-5093
Author(s):  
Yong Hu ◽  
Bing-ke Zhu ◽  
Zhen-shan Yuan ◽  
Wei-xin Dong ◽  
Xiao-yang Sun ◽  
...  
Keyword(s):  
Facet Joint ◽  
Spinous Process ◽  
Anatomical Study ◽  
Transverse Process ◽  
Entry Point ◽  
Anatomic Study ◽  
Angle Error ◽  
Computed Tomographic ◽  
Tomographic Data ◽  
The Ideal

Objective To evaluate the anatomic characteristics of the lumbar lamina and suggest a safe and effective strategy for setting lumbar translaminar facet screws. Methods The width and length of the lumbar lamina, screw path, lateral angle of the lamina, and maximum and minimum caudal angles of the lamina from L3 to L5 were measured with Mimics software using 32 patients’ computed tomographic data. Results The optimal screw entry point was located at the median of the spinous process base or slightly lower. The ideal screw trajectory was from the entry point to the base of the transverse process and across the center of the facet joint. A length of 35 to 45 mm was suitable for L3 to L4 in most cases, and a length of 45 to 50 mm was safe for L5 in most cases. The screw should be inserted at an angle of 49.4° to 59.29° laterally and 43.68° to 57.58° caudally at L3 to L5. For the ideal caudal angle, error of <3° was considered safe. Conclusion The optimal entry point, ideal screw trajectory, ideal screw-setting angles, and safest range of the angle and length of the lumbar lamina were identified in this anatomical study.

scholarly journals Trajectory of Lumbar Translaminar Facet Screw Under Navigation: A Cadaveric Study

2020 ◽  
pp. 219256822096244
Author(s):  
Weerasak Singhatanadgige ◽  
Kittisak Songthong ◽  
Phattareeya Pholprajug ◽  
Wicharn Yingsakmongkol ◽  
Vit Kotheeranurak ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Facet Joint ◽  
Screw Fixation ◽  
Spinous Process ◽  
Transverse Process ◽  
Transforaminal Lumbar Interbody Fusion ◽  
Cadaver Study ◽  
Lateral Angle ◽  
Starting Point ◽  
Screw Length

Study Design: Anatomic cadaver study. Objective: Translaminar facet screw fixation supplements unilateral pedicle screw-rod fixation in minimally invasive transforaminal lumbar interbody fusion (TLIF). Various screw diameters, lengths, trajectories, and insertion points are used; however, they do not represent true screw trajectory. We aimed to evaluate lumbar laminar anatomy and suggest a safe and effective insertion point and trajectory during lumbar-translaminar facet screw fixation in an anatomic cadaver study. Methods: O-arm navigation simulating the true translaminar facet screw trajectory was used to evaluate L1-S1 in cadaveric spines. The inner and outer diameters, length, and trajectory of the screw pathway were measured along the trajectory from the spinous process base through the contralateral lamina, crossing the facet joint to the transverse process base using 2 starting points: cephalad one-third (1/3SL) and one-half (1/2SL) of the spinolaminar junction. Results: Using the 1/2SL starting point, the outer and inner lamina diameters did not differ significantly from L1-L5 (7.47 ± 1.38 to 6.7 ± 1.84 mm and 4.73 ± 1.04 to 3.86 ± 1.46 mm, respectively). Screw length (36.16 ± 4.02 to 49.29 ± 10.07 mm) and lateral angle increased (50.28° ± 8.78° to 60.77° ± 8.88°), but caudal angle decreased (16.19° ± 9.01° to 1.13° ± 11.31°). Lamina diameter and screw length did not differ with different starting points. L2-L3 caudal angles were lower in the 1/2SL starting point. Conclusion: A 36- to 50-mm translaminar facet screw—with 5.0-mm diameter for L1-L2 and 4.5-mm diameter for L3-L5—can be inserted at the middle of the spinolamina, especially during minimally invasive TLIF, with a 50° to 60° lateral angle relative to the spinous process, and a caudal angle of 16° to 1° relative to the spinolamina from L1-L5.

Feasible and Accurate Occipitoatlantal Transarticular Fixation: An Anatomic Study

2010 ◽  
Vol 66 (suppl_1) ◽  
pp. ons-173-ons-177 ◽  
Author(s):  
Mehmet Senoglu ◽  
Sam Safavi-Abbasi ◽  
Nicholas Theodore ◽  
Neil R. Crawford ◽  
Volker K.H. Sonntag
Keyword(s):  
Anatomical Study ◽  
Craniovertebral Junction ◽  
Screw Placement ◽  
Occipital Condyle ◽  
X Rays ◽  
Anatomic Study ◽  
Screw Insertion ◽  
Computed Tomographic ◽  
Entry Points ◽  
Transarticular Fixation

Abstract Background: Defining the anatomic zones for the placement of occiput-C1 transarticular screws is essential for patient safety. Objective: The feasibility and accuracy of occiput-C1 transarticular screw placement were evaluated in this anatomical study of normal cadaveric specimens. Material and Methods: Sixteen measurements were determined for screw entry points, trajectories, and lengths for placement of transarticular screws, as applied in the technique described by Grob, on the craniovertebral junction segments (occiput-C2) of 16 fresh human cadaveric cervical spines and 41 computed tomographic reconstructions of the craniovertebral junction. Acceptable angles for screw positioning were measured on digital x-rays. Results: All 32 screws were placed accurately. As determined by dissection of the specimens, none of the screws penetrated the spinal canal. Screw insertion caused no fractures, and the integrity of the hypoglossal canal was maintained in all the disarticulated specimens. Conclusion: Viable transarticular occiput-C1 screw placement is possible, despite variability of the anatomy of the occipital condyle.

scholarly journals Use of computed tomographic reconstruction to establish the ideal entry point for pedicle screws in idiopathic scoliosis

2011 ◽  
Vol 21 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Peiqiang Su ◽  
Wentong Zhang ◽  
Yan Peng ◽  
Anjing Liang ◽  
Kaili Du ◽  
...  
Keyword(s):  
Idiopathic Scoliosis ◽  
Tomographic Reconstruction ◽  
Pedicle Screws ◽  
Entry Point ◽  
Computed Tomographic ◽  
The Ideal

Accuracy of Pedicle Screw Placement for Lumbar Fusion using Anatomic Landmarks versus Open Laminectomy: A Comparison of Two Surgical Techniques in Cadaveric Specimens

2006 ◽  
Vol 59 (suppl_1) ◽  
pp. ONS-13-ONS-19 ◽  
Author(s):  
Aftab Karim ◽  
Debi Mukherjee ◽  
Jorge Gonzalez-Cruz ◽  
Alan Ogden ◽  
Donald Smith ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Lumbar Fusion ◽  
Entry Point ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Anatomic Landmarks ◽  
Computed Tomographic ◽  
Entry Points ◽  
Tomographic Analysis ◽  
The Ideal

Abstract OBJECTIVE: We determined whether the accuracy of lumbar pedicle screw placement is optimized by performing a laminectomy before screw placement with screw entry point and trajectory being guided by pedicle visualization and palpation (Technique 1). This technique was compared with a technique using anatomic landmarks for pedicle screw placement (Technique 2). The biomechanical stability of the instrumented constructs, in the absence and presence of a laminectomy, was also compared. METHODS: Twelve L1–L3 specimens were harvested from fresh cadavers. The intact laminectomy and instrumented spines were biomechanically tested in flexion and extension, lateral bending, and axial rotation. Laminectomies were performed in six of the 12 specimens before pedicle screw placement using Technique 1. The remaining six specimens underwent pedicle screw and rod fixation using Technique 2. Computed tomographic images were obtained for all instrumented specimens. Deviation of the screws from the ideal entry point or trajectory was analyzed to quantitatively compare the two techniques. RESULTS: Computed tomographic analysis of the specimens showed that all screw placements were within the pedicles. Scatter plot analysis demonstrated that screws placed using Technique 2 were more likely to have the combination of entry points and trajectories medial to the ideal entry point and trajectory. Laminectomy did not weaken the final pedicle screw and rod-fixated constructs. CONCLUSION: All screw placements were grossly within the confines of the pedicles, regardless of technique, as evidenced by computed tomographic analysis. Furthermore, the anatomic landmark technique and the open laminectomy technique yielded biomechanically equivalent pedicle screw and rod-fixated constructs.

Percutaneous Discectomy: An Anatomical Study

Neurosurgery ◽  
1985 ◽  
Vol 16 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Steven L. Kanter ◽  
William A. Friedman
Keyword(s):  
Computed Tomography ◽  
Lumbar Spine ◽  
Vascular Injury ◽  
Anatomical Study ◽  
Intervertebral Discs ◽  
Viable Alternative ◽  
Percutaneous Discectomy ◽  
Computed Tomographic ◽  
Anatomical Analysis ◽  
Computed Tomographic Scan

Abstract Percutaneous discectomy is a viable alternative in the treatment of herniated intervertebral discs of the lumbar spine. Anatomical analysis of the retroperitoneal surgical path utilizing computed tomography suggests that the risk of vascular injury is negligible at the L-4, L-5 level, but substantial at the L-5, S-1 level. In addition, one-third of patients otherwise suitable for percutaneous discectomy have segments of bowel obstructing the surgical path. Obtaining an abdominal computed tomographic scan with the patient in the surgical position seems to be a valuable screening technique in the evaluation of candidates for this procedure.

scholarly journals Posterior Ligamentous Complex Reconstruction for Cervical Dislocation and Instability in Patients without Vertebral Fracture with Artificial Ligaments: A Technical Note

2020 ◽  
Author(s):  
Chengyi Huang ◽  
Beiyu Wang ◽  
Hao Liu ◽  
Tingkui Wu ◽  
Kangkang Huang ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Vertebral Fracture ◽  
Neck Pain ◽  
Facet Joint ◽  
Spinous Process ◽  
Posterior Ligamentous Complex ◽  
Reconstruction Surgery ◽  
Artificial Ligaments ◽  
Cervical Surgery ◽  
Patient Reported

Abstract Introduction: The posterior ligamentous complex (PLC) offers restraints to deformation in a complex and interconnected manner. The stability and range of motion (ROM) of the posterior cervical spine is greatly restricted when the PLC is damaged, even without bone disruptions. We describe a novel surgical technique, its advantages, and the postoperative condition of the first patient to use artificial ligament in a reconstruction surgery of PLC injuries in patients without lower cervical vertebral fracture. This technique aimed to fully retain the mobility of the injured segment based on spinal stability and apply dynamic reconstruction in patients’ treatment.Method: We present a detailed description of the reconstruction surgery with artificial ligaments performed on C4-6 PLC injuries in a 27-year-old male presented with neck pain and restricted movement following a high fall injury accompanied by impaired movement of limbs. Results: Immediately postsurgery, the patient’s neck pain and quadriparesis had been improved. The spinal canal decompression and cervical spine sequence results were satisfactory, the facet joint face was in a good position, and the spinous process spacing returned to normal. After three months of rehabilitation, the patient reported improvement of symptoms and the physical and imaging examination showed a significant improvement in the patient’s condition. The patient’s neck mobility motor function had improved further.Conclusion: The present data demonstrate that the novel technique for reconstruction of PLC injury is feasible and safe. However, familiarity with cervical anatomy and adequate experience in lateral mass screws placement during surgery is crucial for this procedure. Therefore, a highly experienced cervical surgery team is recommended to perform the surgery.

scholarly journals Ideal screw entry point and projection angles for posterior lateral mass fixation of the atlas: an anatomical study

2009 ◽  
Vol 18 (9) ◽  
pp. 1321-1325 ◽  
Author(s):  
Serkan Simsek ◽  
Kazim Yigitkanli ◽  
Hakan Seçkin ◽  
Ayhan Comert ◽  
Halil I. Acar ◽  
...  
Keyword(s):  
Anatomical Study ◽  
Entry Point ◽  
Lateral Mass

scholarly journals Severe Facet Joint Arthrosis Caused C7/T1 Myelopathy: A Case Report

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Toshimi Aizawa ◽  
Hiroshi Ozawa ◽  
Takeshi Hoshikawa ◽  
Takashi Kusakabe ◽  
Eiji Itoi
Keyword(s):  
Cervical Myelopathy ◽  
Rare Case ◽  
Facet Joint ◽  
Spinous Process ◽  
Intervertebral Disc Herniation ◽  
Facet Joints ◽  
Single Level ◽  
Neurological Improvement ◽  
Bony Spur ◽  
Radiological Examinations

Cervical myelopathy is caused by degenerative processes of the spine including intervertebral disc herniation and posterior spur usually developing at C3/4 to C5/6. C7/T1 single level myelopathy is very rare because of the anatomical characteristics. Facet joint arthrosis can be a cause of cervical myelopathy but only a few cases have been reported. The authors report an extremely rare case of C7/T1 myelopathy caused by facet joint arthrosis. A 58-year-old male presented with hand and gait clumsiness. The radiological examinations revealed severe C7/T1 facet joint arthrosis with bony spur extending into the spinal canal, which compressed the spinal cord laterally. The T1 spinous process indicated nonunion of a “clay-shoveler's” fracture, which suggested that his cervico-thoracic spine had been frequently moved, and thus severe arthrosis had occurred in the facet joints. A right hemilaminectomy of C7 and C7/T1 facetectomy with single level spinal fusion led to complete neurological improvement.

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