BIOMECHANICAL STUDY OF PEDICLE SCREW FIXATION STRENGTH: ASSOCIATION OF SCREW MALPOSITION AND SCREW INSERTION TORQUE

2019 ◽  
Vol 19 (02) ◽  
pp. 1940012
Author(s):  
TSUNG-TING TSAI ◽  
YU-HUNG CHEN ◽  
CHAO-YAUG LIAO ◽  
HSIN-TZU LIN ◽  
MU-YI LIU ◽  
...  
Keyword(s):  
Real Time ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Fixation Strength ◽  
Control Group ◽  
Insertion Torque ◽  
Pullout Strength ◽  
Screw Insertion ◽  
Medial Cortex ◽  
Screw Penetration

Pedicle screws have been widely used for the treatment of spinal diseases, but improper screw placement is not uncommon and may lead to neurovascular injuries and reduced screw fixation strength. This study aimed to investigate the feasibility of using real-time screw insertion torque monitoring to prevent screw penetration. Commercially available synthetic L4 vertebrae were divided in to seven test groups based on different screw placements. Screw insertion torque and maximal pullout strength were compared among groups. The results indicated that the insertion torque gradually increased when the screw tip was within vertebral cancellous bone without penetration. However, an instantaneous decrease of torque value was observed once the screw tip penetrated the cortex wall. When compared to the control group, higher pullout strength was found for the groups with medial cortex penetration. However, vertebrae with medial cortex penetration may lead to the concern of neurovascular damage. Meanwhile, lower pullout strength was found for the groups with lateral cortex penetration and end-plate penetration, which may lead to the concern of screw loosening. We concluded that pedicle screw penetration can be judged using real-time screw insertion torque monitoring during surgery, which may aid surgeons in avoiding neurovascular injury and reduction of screw fixation strength.

Feasibility of using tapping torque during lumbar pedicle screw insertion to predict screw fixation strength

2020 ◽  
Vol 25 (3) ◽  
pp. 389-393 ◽  
Author(s):  
Keitaro Matsukawa ◽  
Yoshiyuki Yato ◽  
Hideaki Imabayashi ◽  
Takashi Asazuma ◽  
Kazuhiro Chiba
Keyword(s):  
Pedicle Screw ◽  
Screw Fixation ◽  
Fixation Strength ◽  
Screw Insertion ◽  
Pedicle Screw Insertion ◽  
Lumbar Pedicle

scholarly journals Is Freehand Technique of Pedicle Screw Insertion in Thoracolumbar Spine Safe and Accurate? Assessment of 250 Screws

2019 ◽  
Vol 10 (02) ◽  
pp. 256-260 ◽  
Author(s):  
N. Vijayeswaran ◽  
Raju Venkatesh ◽  
G. Murugesan ◽  
S. Balamurugan ◽  
K. Indunesh ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Screw Fixation ◽  
Thoracolumbar Spine ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Screw Insertion ◽  
Freehand Technique ◽  
Close Observation ◽  
Screw Penetration ◽  
Surgical Duration

ABSTRACT Background: Pedicle screw fixation is one of the widely used procedures for instrumentation and stabilization of the thoracic and lumbar spine. It has the advantage of stabilizing all the three columns in single approach. Various assistive techniques are available to place the pedicle screws more accurately but at the expense of increased exposure to radiation, prolonged surgical duration, and cost. Objective: The objective of this study is to determine the accuracy and safety of pedicle screw fixation in the thoracolumbar spine using freehand surgical technique. Materials and Methods: We evaluated all patients who underwent pedicle screw fixation of the thoracolumbar spine for various ailments at our institute from January 2016 to December 2017 with postoperative computed tomography scan for placement accuracy. We used Gertzbein classification to grade pedicle breaches. Screw penetration more than 4 mm was taken as critical and those less than that were classified as noncritical. Results: A total of 256 screws inserted in T1–L5 vertebrae were included from 40 consecutive patients. Six screws were excluded according to selection criteria. The mean age was 39 years. Trauma (36 patients) was the common reason for which the pedicle screw fixation was done followed by degenerative disease (2 patients) and tumour (2 patients). A total of ten pedicle screw breaches (4%) were identified in eight patients. Among these, three critical breaches (1.2%) were occurred in two patients which required revision. The remaining seven breaches were noncritical and kept under close observation and follow-up. Conclusion: Pedicle screw had become the workhorse of posterior stabilization of the spine. Based on external anatomy and landmarks alone, freehand technique for pedicle screw fixation can be performed with acceptable safety and accuracy avoiding cumulative radiation exposure and prolonged operative time.

Surgeon Perception of Cancellous Screw Fixation

2012 ◽  
Author(s):  
Michael J. Stoesz ◽  
James R. Jastifer ◽  
Joseph L. Chess ◽  
Bipin Patel ◽  
Peter A. Gustafson
Keyword(s):  
Cancellous Bone ◽  
Screw Fixation ◽  
Insertion Torque ◽  
Cancellous Screw ◽  
Screw Insertion ◽  
Factors Associated

The ability of surgeons to optimize screw insertion torque in nonlocking fixation constructs is important for stability, particularly in osteoporotic and cancellous bone. This study evaluated screw torque applied by surgeons during simulated cancellous fixation. It evaluated the frequency that synthetic cancellous bone were stripped by the surgeon, factors associated with bone stripping, and the ability of surgeons to recognize it.

scholarly journals Does Tranexamic Acid Reduce Perioperative Bleeding in Short Segment Pedicle Screw Fixation in Thoracolumbar Spine Fractures?

2015 ◽  
Vol 53 (199) ◽  
pp. 169-173 ◽  
Author(s):  
Rabindra Lal Pradhan ◽  
Bimal Kumar Pandey
Keyword(s):  
Tranexamic Acid ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Thoracolumbar Spine ◽  
Pedicle Screw Fixation ◽  
Control Group ◽  
Thoracolumbar Fractures ◽  
Short Segment ◽  
Perioperative Bleeding ◽  
Thoracolumbar Spine Fractures

Introduction: Blood loss with spinal surgery is common potential cause of morbidity and often requires blood transfusion. Tranexamic acid (TXA), is effective in reducing bleeding in patients undergoing knee arthroplasty. TXA used in spine surgery studies have included different cases leading to inconsistence of surgical procedures. Purpose of this prospective observational study was to examine effect of TXA decreasing bleeding in short segment pedicle screw fixation for thoracolumbar fractures. Methods: 38 patients' undergoing short segment pedicle screw for thoracolumbar fractures were enrolled in study from July to August 2013. There were 28 male and 10 female patients, with an average age of 36.5 years. Patients received 10 mg/kg of TXA or a control 30 minutes intravenously before skin incision and 3 hours post-operative and oral medication for three days. Intraoperative bleeding was estimated by weighing surgical sponges, blood collected by suction container and by subtracting all irrigation fluid. Postoperative bleeding was measured from volume in vacuum drainage bag. Results: Twenty (20) patients were in control group and eighteen(18) to TXA group. There were no statistical differences between groups in terms of age, gender, co-morbidities, and operating time, preoperative Hemoglobin, PT and INR. Intra-operative bleeding in TXA group was significant than in control group. Post-operative drainage and Hemoglobin in first 48 h was reduced compared with placebo in TXA group. Need for post-operative transfusion was nil in TXA group. Conclusions: Administration of TXA before surgery significantly reduces perioperative bleeding in patients undergoing short segment pedicle screw fixation for thoracolumbar spine fractures.  Keywords: bleeding; spinal surgery; tranexamic acid.

Insertion Torque Profile During Pedicle Screw Insertion of the Thoracic Spine With and Without Violation of the Pedicle Wall

Spine ◽  
2006 ◽  
Vol 31 (22) ◽  
pp. E840-E846 ◽  
Author(s):  
Hwan T. Hee ◽  
Mohammad Shazad Khan ◽  
James C. Goh ◽  
Hee K. Wong
Keyword(s):  
Pedicle Screw ◽  
Thoracic Spine ◽  
Insertion Torque ◽  
Screw Insertion ◽  
Pedicle Screw Insertion ◽  
Pedicle Wall

Drilling Energy Correlates With Screw Insertion Torque, Screw Compression, and Pullout Strength: A Cadaver Study

2020 ◽  
Vol 28 (24) ◽  
pp. e1121-e1128
Author(s):  
Michael J. Chen ◽  
Malcolm R. DeBaun ◽  
Timothy Thio ◽  
Hunter Storaci ◽  
Michael J. Gardner
Keyword(s):  
Cadaver Study ◽  
Insertion Torque ◽  
Pullout Strength ◽  
Screw Insertion

Optimization of Pedicle Screw Depth in the Lumbar Spine

2013 ◽  
Author(s):  
Laura E. Buckenmeyer ◽  
Kristophe J. Karami ◽  
Ata M. Kiapour ◽  
Vijay K. Goel ◽  
Teck M. Soo ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Fixation Strength ◽  
Osteoporotic Patient ◽  
Insertion Depth ◽  
Anterior Cortex ◽  
Screw Insertion ◽  
Clinical Challenge ◽  
Series Of Experiments

Optimization of pedicle screw insertion depth for ideal fixation and fusion remains a clinical challenge. Improved screw purchase may improve fixation strength 1, which is especially critical in an osteoporotic patient population. Extended screw insertion depths, up to and through the anterior cortex, have yet to be compared to more commonly used shorter pedicle screws in a laboratory controlled series of experiments. The purpose of this study is to evaluate screw purchase in the osteoporotic lumbar spine as a function of insertion depth, which may be used to optimize pedicle screw-rod constructs.

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