Power-assisted pedicle screws placement: Is it as safe and as effective as manual technique? Narrative review of the literature and our technique

AbstractPedicle screws are the gold standard in spine surgery, allowing a solid tricolumnar fixation which is unmatched by hooks and wires. The freehand technique is the most widely adopted for pedicle screws placing. While freehand technique has been classically performed with manual tools, there has been a recent trend toward the use of power tools. The aim of this review is to summarize and expose potential risks and advantages of power pedicle screws placing. The literature showed that the use of power tools offers an acceptable safety profile, comparable to manual technique. With an adequate training, the power technique may speed up the screw placing, reduce the fluoroscopy time and the physical stress to the spine surgeon. Regarding differences in pull-out strength between power and manual techniques, the literature is still uncertain and inconsistent, both in clinical and preclinical studies. The choice between the use of power and manual freehand pedicle screws placing is still based on the surgeon’s own preference.

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A Novel Technique for Measuring Pedicle Screw Forces In Situ

ASME 2008 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2008-192219 ◽

2008 ◽

Cited By ~ 1

Author(s):

Samuel Q. Tia ◽

Jennifer M. Buckley ◽

Thuc-Quyen Nguyen ◽

Jeffrey C. Lotz ◽

Shane Burch

Keyword(s):

Pedicle Screw ◽

Pedicle Screws ◽

Clinical Failure ◽

Strain Gages ◽

Destructive Testing ◽

Novel Technique ◽

Pull Out ◽

Pull Out Strength

Long posterior fusion constructs in the lumbar spine cause substantial posteriorly directed loading of the supporting pedicle screws, particularly during patient bending activities. Although there are numerous documented accounts of clinical failure at the pedicle screw-bone interface [1,2], the in situ pull-out strength of pedicle screws in long surgical constructs has not been characterized. Previous biomechanical studies have quantified pedicle screw pull-out force in cadaveric models through destructive testing or in nondestructive cases, through the use of custom-machined pedicle screws instrumented with strain gages [3–6]. However, these techniques involve altering screw geometry and may fail to properly simulate in vivo mechanical loading conditions. The goal of this study was to develop and validate a sensor system for measuring pedicle screw pull-out forces in long posterior constructs in situ during multi-segmental cadaveric testing.

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Pull out strength calculator for pedicle screws using a surrogate ensemble approach

Computer Methods and Programs in Biomedicine ◽

10.1016/j.cmpb.2016.08.023 ◽

2016 ◽

Vol 137 ◽

pp. 11-22 ◽

Cited By ~ 12

Author(s):

Vicky Varghese ◽

Palaniappan Ramu ◽

Venkatesh Krishnan ◽

Gurunathan Saravana Kumar

Keyword(s):

Pedicle Screws ◽

Ensemble Approach ◽

Pull Out ◽

Pull Out Strength

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Correlation between the Computed Tomography Values of the Screw Path and Pedicle Screw Pullout Strength: An Experimental Study in Porcine Vertebrae

Asian Spine Journal ◽

10.31616/asj.2019.0170 ◽

2020 ◽

Vol 14 (3) ◽

pp. 265-272

Author(s):

Atsushi Ikeura ◽

Taketoshi Kushida ◽

Kenichi Oe ◽

Yoshihisa Kotani ◽

Muneharu Ando ◽

...

Keyword(s):

Computed Tomography ◽

Bone Mineral Density ◽

Pedicle Screw ◽

Bone Mineral ◽

Lumbar Vertebrae ◽

Pedicle Screws ◽

Mineral Density ◽

Screw Insertion ◽

Pull Out ◽

Pull Out Strength

Study Design: Biomechanical study.Purpose: To assess the correlation between the computed tomography (CT) values of the pedicle screw path and screw pull-out strength.Overview of Literature: The correlation between pedicle screw pull-out strength and bone mineral density has been well established. In addition, several reports have demonstrated a correlation between bone mineral density and CT values. However, no previous biomechanical studies investigated the correlation between CT values and pedicle screw pull-out strength.Methods: Sixty fresh-frozen lumbar vertebrae from 6-month-old pigs were used. Before screw insertion, the CT values of the screw path were obtained for each sample. Specimens were then randomly divided into three equal groups. Each group had one of three pedicle screws inserted: 4.0-mm LEGACY (4.0-LEG), 4.5-mm LEGACY (4.5-LEG), or 4.5-mm SOLERA (4.5-SOL) (all from Medtronic Sofamor Danek Inc., Memphis, TN, USA). Each screw had a consistent 30-mm thread length. Axial pull-out testing was performed at a rate of 1.0 mm/min. Correlations between the CT values and pedicle screw pull-out strength were evaluated using Pearson’s correlation coefficient analysis.Results: The correlation coefficients between the CT values of the screw path and pedicle screw pull-out strength for the 4.0-LEG, 4.5-LEG, and 4.5-SOL groups were 0.836 (p <0.001), 0.780 (p <0.001), and 0.873 (p <0.001), respectively. Greater CT values were associated with greater screw pull-out strength.Conclusions: The CT values of the screw path were strongly positively correlated with pedicle screw pull-out strength, regardless of the screw type and diameter, suggesting that the CT values could be clinically useful for predicting pedicle screw pull-out strength.

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Comparative Experimental Study of Hook and Pedicle Fixation Systems Used at Surgical Treatment of Spine Deformities

N.N. Priorov Journal of Traumatology and Orthopedics ◽

10.17816/vto20120320-24 ◽

2012 ◽

Vol 19 (3) ◽

pp. 20-24 ◽

Cited By ~ 1

Author(s):

A. A Kuleshov ◽

I. N Lisyansky ◽

M. S Vetrile ◽

N. S Gavryushenko ◽

L. V Fomin

Keyword(s):

Static Load ◽

Testing Machine ◽

Pedicle Screws ◽

Cyclic Loads ◽

Pedicle Fixation ◽

Pull Out ◽

Spine Deformities ◽

Laminar Hooks ◽

Vertebral Arch ◽

Pull Out Strength

Using human cadaver spines we compared the stiffness of pedicle screws and laminar hooks under cyclic and static pull-out loads. Transpedicular and hook fixation (sub- and supralaminar) of cadaveric thoracic spine segments was performed. Axial pull-out strength was measured using w+b (walter + bai ag) servoelectric testing machine (LFV-10-T50, Switzerland). Static pull-out tests were performed on 7 spine blocks with transpedicular and 7 blocks with hook fixation. The same blocks were tested under cyclic loads. At cyclic pull-out loading 800 N strength with 5 Hz frequency was applied. It was shown that at increasing static load hook implants could bear 1417 N at average. At higher loads the vertebral arch was destroyed. Transpedicular implants could bear 2286 N at average and at higher loads the screw migrated from the arch root. Cyclic tests showed that hooks could bear 2935 cycles at average and at prolonged loading the arch was destroyed. The hooks could bear the full; program of cyclic loads without destruction (18 000 cycles).

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Correlation of pull-out strength of cement-augmented pedicle screws with CT-volumetric measurement of cement

Biomedical Engineering / Biomedizinische Technik ◽

10.1515/bmt-2012-0012 ◽

2012 ◽

Vol 57 (6) ◽

Cited By ~ 28

Author(s):

Christian Fölsch ◽

Hans Goost ◽

Jens Figiel ◽

Jürgen R.J. Paletta ◽

Wolfgang Schultz ◽

...

Keyword(s):

Pedicle Screws ◽

Volumetric Measurement ◽

Pull Out ◽

Pull Out Strength

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Accuracy of the freehand technique for 3 fixation methods in the C-2 vertebrae

Neurosurgical FOCUS ◽

10.3171/2011.6.focus1167 ◽

2011 ◽

Vol 31 (4) ◽

pp. E11 ◽

Cited By ~ 10

Author(s):

Melvin D. Helgeson ◽

Ronald A. Lehman ◽

Anton E. Dmitriev ◽

Daniel G. Kang ◽

Rick C. Sasso ◽

...

Keyword(s):

Intraoperative Imaging ◽

Pedicle Screws ◽

Dorsal Cortex ◽

Accuracy Rate ◽

Screw Insertion ◽

Medial Cortex ◽

Freehand Technique ◽

Spine Surgeon ◽

Critical Violations ◽

Ventral Canal

Object Intraoperative imaging often does not provide adequate visualization to ensure safe placement of screws. Therefore, the authors investigated the accuracy of a freehand technique for placement of pars, pedicle, and intralaminar screws in C-2. Methods Sixteen cadaveric specimens were instrumented freehand by 2 experienced cervical spine surgeons with either a pars or pedicle screw, and bilateral intralaminar screws. The technique was based on anatomical starting points and published screw trajectories. A pedicle finder was used to establish the trajectory, followed by tapping, palpation, and screw placement. After placement of all screws (16 pars screws, 16 pedicle screws, and 32 intralaminar screws), the C-2 segments were disarticulated, radiographed in anteroposterior, lateral, and axial planes, and meticulously inspected by another spine surgeon to determine the nature and presence of any defects. Results A total of 64 screws were evaluated in this study. Pars screws exhibited 2 critical defects (1 in the foramen transversarium and 1 in the C2–3 facet) and an insignificant dorsal cortex breech, for an overall accuracy rate of 81.3%. Pedicle screws demonstrated only 1 insignificant violation (inferior facet/medial cortex intrusion of 1 mm) with an accuracy rate of 93.8%, and intralaminar screws demonstrated 3 insignificant violations (2 in the ventral canal, 1 in the caudad lamina breech) for an accuracy rate of 90.6%. Pars screws had significantly more critical violations than intralaminar screws (p = 0.041). Conclusions Instrumentation of the C-2 vertebrae using the freehand technique for insertion of pedicle and intralaminar screws showed a high success rate with no critical violations. Pars screw insertion was not as reliable, with 2 critical violations from a total of 16 placements. The freehand technique appears to be a safe and reliable method for insertion of C-2 pedicle and intralaminar screws.

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Pull-out strength of cemented solid versus fenestrated pedicle screws in osteoporotic vertebrae

Bone and Joint Research ◽

10.1302/2046-3758.59.2000580 ◽

2016 ◽

Vol 5 (9) ◽

pp. 419-426 ◽

Cited By ~ 22

Author(s):

C. I. Leichtle ◽

A. Lorenz ◽

S. Rothstock ◽

J. Happel ◽

F. Walter ◽

...

Keyword(s):

Pedicle Screws ◽

Pull Out ◽

Pull Out Strength

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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

10.21203/rs.3.rs-429747/v1 ◽

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.

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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

BMC Research Notes ◽

10.1186/s13104-021-05803-5 ◽

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.

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