scholarly journals Possible Usage of Cannulated Pedicle Screws without Cement Augmentation

2014 ◽  
Vol 11 (3) ◽  
pp. 149-155 ◽  
Author(s):  
Teyfik Demir
Keyword(s):  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Cement Augmentation ◽  
Control Group ◽  
Pullout Strength ◽  
Screw Design ◽  
Pullout Tests ◽  
Pu Foam ◽  
Common Problems ◽  
Testing Protocols

Background: The use of pedicle screws is becoming increasingly popular for spinal surgery practice as the technology advances. Screw pullout due to bone quality and loading conditions is one of the most common problems observed after pedicle screw fixation. Several solutions were studied to prevent screw pullout. These can be investigated under three main categories: screw design, expandable screws and cement augmentation.Objective: This study aimed to investigate the pullout performance of cannulated screws without cement augmentation on synthetic foams.Methods: Artificial fusion process for PU is described and validated in our previous studies. For this study six newly designed cannulated pedicle screws were artificially fused to PU foam and pullout test were conducted according to ASTM F543 standard testing protocols.Results: According to the results of post-fusion pullout tests, worst performed cannulated screw design was S3H on healthy bone simulating PU foam. However, pullout strength of unilaterally three holes including (S3H) design was purchased with two times higher loads when compared to control group. Solid cored screws were purchased with 671 N where this value was 1450 N for S3H design.Conclusions: This study provided that using cannulated pedicle screws without cement augmentation for the cases with healthy bone can be a reliable alternative to classical screws. To the knowledge of the authors this is the first post-fusion study investigating cannulated pedicle screws without cement augmentation.

Pullout strength for cannulated pedicle screws with bone cement augmentation in severely osteoporotic bone: Influences of radial hole and pilot hole tapping

2009 ◽  
Vol 24 (8) ◽  
pp. 613-618 ◽  
Author(s):  
Lih-Huei Chen ◽  
Ching-Lung Tai ◽  
Po-Liang Lai ◽  
De-Mei Lee ◽  
Tsung-Tin Tsai ◽  
...  
Keyword(s):  
Bone Cement ◽  
Pedicle Screws ◽  
Cement Augmentation ◽  
Osteoporotic Bone ◽  
Pullout Strength ◽  
Pilot Hole

scholarly journals Balancing Rigidity and Safety of Pedicle Screw Fixation via a Novel Expansion Mechanism in a Severely Osteoporotic Model

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Thomas M. Shea ◽  
James J. Doulgeris ◽  
Sabrina A. Gonzalez-Blohm ◽  
William E. Lee ◽  
Kamran Aghayev ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Cortical Layer ◽  
Fixation Strength ◽  
Osteoporotic Bone ◽  
Pullout Strength ◽  
Initial Fixation ◽  
Increased Risk

Many successful attempts to increase pullout strength of pedicle screws in osteoporotic bone have been accompanied with an increased risk of catastrophic damage to the patient. To avoid this, a single-armed expansive pedicle screw was designed to increase fixation strength while controlling postfailure damage away from the nerves surrounding the pedicle. The screw was then subsequently tested in two severely osteoporotic models: one representing trabecular bone (with and without the presence of polymethylmethacrylate) and the other representing a combination of trabecular and cortical bone. Maximum pullout strength, stiffness, energy to failure, energy to removal, and size of the resulting block damage were statistically compared among conditions. While expandable pedicle screws produced maximum pullout forces less than or comparable to standard screws, they required a higher amount of energy to be fully removed from both models. Furthermore, damage to the cortical layer in the composite test blocks was smaller in all measured directions for tests involving expandable pedicle screws than those involving standard pedicle screws. This indicates that while initial fixation may not differ in the presence of cortical bone, the expandable pedicle screw offers an increased level of postfailure stability and safety to patients awaiting revision surgery.

scholarly journals Flexibility and fatigue evaluation of oblique as compared with anterior lumbar interbody cages with integrated endplate fixation

2016 ◽  
Vol 24 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Andrew L. Freeman ◽  
William J. Camisa ◽  
Glenn R. Buttermann ◽  
James R. Malcolm
Keyword(s):  
Fatigue Testing ◽  
Plate Fixation ◽  
Pedicle Screws ◽  
Test Group ◽  
Pedicle Screw Fixation ◽  
Pullout Resistance ◽  
Pullout Tests ◽  
Cage Subsidence ◽  
Fatigue Evaluation

OBJECT This study was undertaken to quantify the in vitro range of motion (ROM) of oblique as compared with anterior lumbar interbody devices, pullout resistance, and subsidence in fatigue. METHODS Anterior and oblique cages with integrated plate fixation (IPF) were tested using lumbar motion segments. Flexibility tests were conducted on the intact segments, cage, cage + IPF, and cage + IPF + pedicle screws (6 anterior, 7 oblique). Pullout tests were then performed on the cage + IPF. Fatigue testing was conducted on the cage + IPF specimens for 30,000 cycles. RESULTS No ROM differences were observed in any test group between anterior and oblique cage constructs. The greatest reduction in ROM was with supplemental pedicle screw fixation. Peak pullout forces were 637 ± 192 N and 651 ± 127 N for the anterior and oblique implants, respectively. The median cage subsidence was 0.8 mm and 1.4 mm for the anterior and oblique cages, respectively. CONCLUSIONS Anterior and oblique cages similarly reduced ROM in flexibility testing, and the integrated fixation prevented device displacement. Subsidence was minimal during fatigue testing, most of which occurred in the first 2500 cycles.

scholarly journals Comparison of Insertion Time, Pull-out Strength, and Screw-media Interface Area of Customized Pedicle Screw With Different Core and Thread Design Against Commercial Pedicle Screw

2021 ◽  
Author(s):  
Rahadyan Magetsari ◽  
Tedjo Rukmoyo ◽  
Marda Ade Saputra ◽  
Yudha Mathan Sakti
Keyword(s):  
Pedicle Screw ◽  
Pedicle Screws ◽  
Insertion Time ◽  
Control Group ◽  
Interface Area ◽  
Screw Design ◽  
Pull Out ◽  
Thread Diameter ◽  
Screw Group ◽  
Pull Out Strength

Abstract Objective: This research aimed to developing customized pedicle screw based on Indonesian vertebral anatomy and compare the insertion time, pull-out strength, and screw-media interface area of different screw design. We have developed 3 different types of pedicle screws (v-thread cylinder-core, square-thread cylinder-core and square-thread conical-core). The thread diameter was calculated from pedicle width of Indonesian population (6 mm). We used commercially available pedicle screw as control group (6.2 mm). Result: The insertion time were significantly difference between v-thread cylinder-core pedicle screw (22,94 s) with commercially available pedicle screw (15.86 s) (p<0.05). The pull-out strength was significantly difference between commercially available pedicle screw (408.60 N) with square-thread conical pedicle screw (836.60 N) (p<0.05). The square-thread conical-core group have the highest interface area (1486.21 mm2). The data comparison showed that the square-thread conical-core customized pedicle screw group has comparable insertion time and has better pull-out strength than commercially available pedicle screw.

scholarly journals Comparison of insertion time, pull-out strength, and screw-media interface area of customized pedicle screw with different core and thread design against commercial pedicle screw: a pilot study on Indonesian Population

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Rahadyan Magetsari ◽  
Tedjo Rukmoyo ◽  
Marda Ade Saputra ◽  
Yudha Mathan Sakti
Keyword(s):  
Pedicle Screw ◽  
Pedicle Screws ◽  
Insertion Time ◽  
Control Group ◽  
Interface Area ◽  
Screw Design ◽  
Pull Out ◽  
Indonesian Population ◽  
Thread Diameter ◽  
Pull Out Strength

Abstract Objective This research aimed to developing customized pedicle screw based on Indonesian vertebral anatomy and compare the insertion time, pull-out strength, and screw-media interface area of different screw design. We have developed 3 different types of pedicle screws (v-thread cylinder-core, square-thread cylinder-core and square-thread conical-core). The thread diameter was calculated from pedicle width of Indonesian population (6 mm). We used commercially available pedicle screw as control group (6.2 mm). Result The insertion time were significantly difference between v-thread cylinder-core pedicle screw (22.94 s) with commercially available pedicle screw (15.86 s) (p < 0.05). The pull-out strength was significantly difference between commercially available pedicle screw (408.60 N) with square-thread conical pedicle screw (836.60 N) (p < 0.05). The square-thread conical-core group have the highest interface area (1486.21 mm2). The data comparison showed that the square-thread conical-core customized pedicle screw group has comparable insertion time and has better pull-out strength than commercially available pedicle screw.

scholarly journals A Prospective Study on the Feasibility, Safety, and Efficacy of a Modified Technique to Augment the Strength of Pedicle Screw in Osteoporotic Spine Fixation

2020 ◽  
Vol 14 (3) ◽  
pp. 357-363 ◽  
Author(s):  
Vikas Tandon ◽  
Kalyan Kumar Varma Kalidindi ◽  
Sandesh Pacha ◽  
Mohd Rafiq Bhat
Keyword(s):  
Prospective Study ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Standard Of Care ◽  
Pedicle Screw Fixation ◽  
Cement Augmentation ◽  
Modified Technique ◽  
A Prospective Study ◽  
Spine Fixation

Study Design: Prospective case study.Purpose: Osteoporotic spine fixation by pedicle screw instrumentation is complicated by screw loosening, migration, or pullout with rates of up to 62% documented in the literature. Contemporary solutions have not adequately addressed these complications. We propose a modified surgical technique of cement augmentation with bicortical pedicle screw fixation to address the issue related to implant failure in osteoporotic spine.Overview of Literature: Zindrick and his colleagues described a “windshield wiper” effect owing to the shift of center of rotation to the distal tip of the screw in the bicortical purchase of screws. An increase in pullout strength from 119% to 250% with polymethyl methacrylate augmentation has been documented in the literature. This technique has not been described in the literature.Methods: A prospective study was conducted with 40 patients who underwent surgery by the modified technique. Intraoperative and postoperative complications directly related to the procedure were assessed. Improvement in pain and functional status were assessed. Follow-up radiographs were assessed to check for appreciable screw migration, loosening, or pullout.Results: This technique was used in inserting 364 screws in 40 patients. We did not encounter any difficulty in inserting the screws. A total of 19 screws failed to breach the anterior cortex owing to an error in measurement. There were no complications during the procedure in any of the patients, and the postoperative period was uneventful. The mean follow-up period was 18 months. There were two patients in whom proximal junctional failure with kyphosis was noted during follow-up, who were surgically managed by extension of the fixation levels.Conclusions: Bicortical fixation with cement augmentation is a technically feasible, safe, and effective technique to augment the strength of pedicle screws in osteoporotic spine fixation. It has the potential to be established as a standard of care in osteoporotic spine fixation.

A biomechanical cadaveric analysis of polymethylmethacrylate-augmented pedicle screw fixation

2007 ◽  
Vol 7 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Bruce M. Frankel ◽  
Sabino D'Agostino ◽  
Chiang Wang
Keyword(s):  
Pedicle Screw ◽  
Screw Fixation ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Screw Placement ◽  
Pullout Strength ◽  
Mineral Density ◽  
Hardware Failure ◽  
Screw Augmentation ◽  
Valuable Adjunct

Object Instrumentation of the osteoporotic spine can be fraught with complications such as hardware failure. A cadaver study was performed to determine the biomechanical performance of polymethylmethacrylate (PMMA)–augmented pedicle screws. Methods Three osteoporotic human cadaveric specimens with a mean bone mineral density of 0.70 g/cm2 were used to evaluate the performance of a novel fenestrated bone tap in pedicle screw augmentation. On this device, tap threads serve a dual purpose in preventing backflow of cement toward neural elements while allowing for a custom form for subsequent screw placement. The tap was used to inject a mean volume of 3.7 ml PMMA/pedicle (range 2–8.0 ml PMMA/pedicle) followed by pedicle screw placement between L-5 and T-5, alternating between augmented and nonaugmented instrumentation. Axial pullout testing was then performed. Results Pedicle screw pullout strength was increased in both primary and salvage procedures by 119% (p = 0.001) and 162% (p = 0.01), respectively, after PMMA augmentation. Additionally, the injected cement volumes were divided into two groups, a low-cement group (≤ 2.8 ml/pedicle) and a high-cement group (≥ 5.5 ml/pedicle). Interestingly, the pullout strength did not significantly change with increased cement usage between the two groups (p > 0.05 for all comparisons). Conclusions Polymethylmethacrylate-augmented pedicle screw fixation results in a significant increase in the axial pullout strength of augmented pedicle screws in both primary and revision procedures. This technique may be a valuable adjunct in cases in which bolstering of the screw–bone interface is necessary.

scholarly journals A Biomechanical Comparison of Expansive Pedicle Screws for Severe Osteoporosis: The Effects of Screw Design and Cement Augmentation

PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0146294 ◽  
Author(s):  
Ching-Lung Tai ◽  
Tsung-Ting Tsai ◽  
Po-Liang Lai ◽  
Yi-Lu Chen ◽  
Mu-Yi Liu ◽  
...  
Keyword(s):  
Pedicle Screws ◽  
Cement Augmentation ◽  
Severe Osteoporosis ◽  
Screw Design ◽  
Biomechanical Comparison

scholarly journals The effect of cement augmentation on pedicle screw fixation under various load cases

2021 ◽  
Vol 10 (12) ◽  
pp. 797-806
Author(s):  
Yan Chevalier ◽  
Maiko Matsuura ◽  
Sven Krüger ◽  
Hannes Traxler ◽  
Christoph Fleege† ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Bone Quality ◽  
Pedicle Screws ◽  
Bending Stiffness ◽  
Cement Augmentation ◽  
Fixation Strength ◽  
Screw Design ◽  
Pull Out ◽  
Local Bone ◽  
Significant Difference

Aims Anchorage of pedicle screw rod instrumentation in the elderly spine with poor bone quality remains challenging. Our study aims to evaluate how the screw bone anchorage is affected by screw design, bone quality, loading conditions, and cementing techniques. Methods Micro-finite element (µFE) models were created from micro-CT (μCT) scans of vertebrae implanted with two types of pedicle screws (L: Ennovate and R: S4). Simulations were conducted for a 10 mm radius region of interest (ROI) around each screw and for a full vertebra (FV) where different cementing scenarios were simulated around the screw tips. Stiffness was calculated in pull-out and anterior bending loads. Results Experimental pull-out strengths were excellently correlated to the µFE pull-out stiffness of the ROI (R2 > 0.87) and FV (R2 > 0.84) models. No significant difference due to screw design was observed. Cement augmentation increased pull-out stiffness by up to 94% and 48% for L and R screws, respectively, but only increased bending stiffness by up to 6.9% and 1.5%, respectively. Cementing involving only one screw tip resulted in lower stiffness increases in all tested screw designs and loading cases. The stiffening effect of cement augmentation on pull-out and bending stiffness was strongly and negatively correlated to local bone density around the screw (correlation coefficient ( R) = -0.95). Conclusion This combined experimental, µCT and µFE study showed that regional analyses may be sufficient to predict fixation strength in pull-out and that full analyses could show that cement augmentation around pedicle screws increased fixation stiffness in both pull-out and bending, especially for low-density bone. Cite this article: Bone Joint Res 2021;10(12):797–806.

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