Influence of the screw augmentation technique and a diameter increase on pedicle screw fixation in the osteoporotic spine: pullout versus fatigue testing

2014 ◽  
Vol 23 (10) ◽  
pp. 2196-2202 ◽  
Author(s):  
Rebecca A. Kueny ◽  
Jan P. Kolb ◽  
Wolfgang Lehmann ◽  
Klaus Püschel ◽  
Michael M. Morlock ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Fatigue Testing ◽  
Screw Fixation ◽  
Pedicle Screw Fixation ◽  
Screw Augmentation

INVESTIGATION INTO WHETHER OR NOT PMMA BONE CEMENT TRANSPEDICULAR SCREW AUGMENTATION STABILIZES PEDICLE SCREW LOOSENING

2019 ◽  
Vol 19 (02) ◽  
pp. 1940024
Author(s):  
PO-YI LIU ◽  
SHENG-CHIH LIN ◽  
PO-LIANG LAI ◽  
CHUN-LI LIN
Keyword(s):  
Bone Cement ◽  
Pedicle Screw ◽  
Fatigue Resistance ◽  
Fatigue Testing ◽  
Pedicle Screw Fixation ◽  
Screw Loosening ◽  
General Technique ◽  
Screw Augmentation ◽  
Pmma Bone Cement ◽  
Pedicle Screw Loosening

Pedicle screw loosening at the bone–screw interface is the main complication in pedicle screw fixation. The transpedicular polymethylmethacrylate screw augmentation technique has recently become the general technique used to re-operatively overcome pedicle screw loosening. This study investigates the fatigue resistance of PMMA bone cement augmentation. Twenty-seven porcine thoracic vertebral bodies were collected. The BMD was measured using dual X-ray absorptiometry. Each vertebral body was instrumented with one pedicle screw and mounted in a material testing system. Fatigue testing was performed by implementing a cranio-caudal sinusoidal, cyclic (5[Formula: see text]Hz) load. This study shows that transpedicular pedicle screw augmentation with PMMA exhibits similar fatigue resistance as traditional pedicle screw implantation. However, in histomophometrical analysis, the transpedicular pedicle screw augmentation with PMMA has greater anti-deformation capacity than traditional pedicle screw implantation. Transpedicular pedicle screw augmentation with PMMA improves more screw holding power to prevent pedicle screw loosening.

Finite Element Study to Evaluate the Biomechanical Performance of the Spine After Augmenting Percutaneous Pedicle Screw Fixation With Kyphoplasty in the Treatment of Burst Fractures

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Shady S. Elmasry ◽  
Shihab S. Asfour ◽  
Francesco Travascio
Keyword(s):  
Finite Element ◽  
Pedicle Screw ◽  
Fatigue Testing ◽  
Screw Fixation ◽  
Pedicle Screw Fixation ◽  
Thoracolumbar Burst Fractures ◽  
Hardware Failure ◽  
Burst Fractures ◽  
Percutaneous Pedicle Screw ◽  
Percutaneous Pedicle Screw Fixation

Percutaneous pedicle screw fixation (PPSF) is a well-known minimally invasive surgery (MIS) employed in the treatment of thoracolumbar burst fractures (TBF). However, hardware failure and loss of angular correction are common limitations caused by the poor support of the anterior column of the spine. Balloon kyphoplasty (KP) is another MIS that was successfully used in the treatment of compression fractures by augmenting the injured vertebral body with cement. To overcome the limitations of stand-alone PPSF, it was suggested to augment PPSF with KP as a surgical treatment of TBF. Yet, little is known about the biomechanical alteration occurred to the spine after performing such procedure. The objective of this study was to evaluate and compare the immediate post-operative biomechanical performance of stand-alone PPSF, stand-alone-KP, and KP-augmented PPSF procedures. Novel three-dimensional (3D) finite element (FE) models of the thoracolumbar junction that describes the fractured spine and the three investigated procedures were developed and tested under mechanical loading conditions. The spinal stiffness, stresses at the implanted hardware, and the intradiscal pressure at the upper and lower segments were measured and compared. The results showed no major differences in the measured parameters between stand-alone PPSF and KP-augmented PPSF procedures, and demonstrated that the stand-alone KP may restore the stiffness of the intact spine. Accordingly, there was no immediate post-operative biomechanical advantage in augmenting PPSF with KP when compared to stand-alone PPSF, and fatigue testing may be required to evaluate the long-term biomechanical performance of such procedures.

scholarly journals Cement leakage in pedicle screw augmentation: a prospective analysis of 98 patients and 474 augmented pedicle screws

2016 ◽  
Vol 25 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Jan U. Mueller ◽  
Joerg Baldauf ◽  
Sascha Marx ◽  
Michael Kirsch ◽  
Henry W. S. Schroeder ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Screw Fixation ◽  
Pedicle Screws ◽  
High Volume ◽  
Cement Leakage ◽  
Pedicle Screw Fixation ◽  
Screw Loosening ◽  
Pedicle Screw Placement ◽  
Screw Augmentation ◽  
Cement Embolism

OBJECTIVE Loosening and pullout of pedicle screws are well-known problems in pedicle screw fixation surgery. Augmentation of pedicle screws with bone cement, first described as early as 1975, increases the pedicle-screw interface and pullout force in osteoporotic vertebrae. The aim of the present study was to identify cement leakage and pulmonary embolism rates in a large prospective single-center series of pedicle screw augmentations. METHODS All patients who underwent cement-augmented pedicle screw placement between May 2006 and October 2010 at the authors' institution were included in this prospective cohort study. Perivertebral cement leakage and pulmonary cement embolism were evaluated with a CT scan of the area of operation and with a radiograph of the chest, respectively. RESULTS A total of 98 patients underwent placement of cement-augmented pedicle screws; 474 augmented screws were inserted in 237 vertebrae. No symptomatic perivertebral cement leakage or symptomatic pulmonary cement embolism was observed, but asymptomatic perivertebral cement leakage was seen in 88 patients (93.6%) and in 165 augmented vertebrae (73.3%). Cement leakage most often occurred in the perivertebral venous system. Clinically asymptomatic pulmonary cement embolism was found in 4 patients (4.1%). CONCLUSIONS Perivertebral cement leakage often occurs in pedicle screw augmentation, but in most cases, it is clinically asymptomatic. Cement augmentation should be performed under continuous fluoroscopy to avoid high-volume leakage. Alternative strategies, such as use of expandable screws, should be examined in more detail for patients at high risk of screw loosening.

A method for the fatigue testing of pedicle screw fixation devices

1994 ◽  
Vol 27 (11) ◽  
pp. 1383-1388 ◽  
Author(s):  
Vijay K. Goel ◽  
John M. Winterbottom ◽  
James N. Weinstein
Keyword(s):  
Pedicle Screw ◽  
Fatigue Testing ◽  
Screw Fixation ◽  
Pedicle Screw Fixation ◽  
Fixation Devices

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 Thoracic spondylotic myelopathy presumably caused by diffuse idiopathic skeletal hyperostosis in a patient who underwent decompression and percutaneous pedicle screw fixation

2021 ◽  
Vol 9 ◽  
pp. 2050313X2098779
Author(s):  
Shota Miyoshi ◽  
Tadao Morino ◽  
Haruhiko Takeda ◽  
Hiroshi Nakata ◽  
Masayuki Hino ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Screw Fixation ◽  
Diffuse Idiopathic Skeletal Hyperostosis ◽  
Pedicle Screw Fixation ◽  
Vertebral Bone ◽  
Bone Bridge ◽  
Percutaneous Pedicle Screw ◽  
Bilateral Lower Limb ◽  
Upper Thoracic ◽  
Percutaneous Pedicle Screw Fixation

A 74-year-old man developed bilateral lower limb spastic paresis. He was diagnosed with thoracic spondylotic myelopathy presumably caused by mechanical stress that was generated in the intervertebral space (T1-T2) between a vertebral bone bridge (C5-T1) due to diffuse idiopathic skeletal hyperostosis after anterior fixation of the lower cervical spine and a vertebral bone bridge (T2-T7) due to diffuse idiopathic skeletal hyperostosis in the upper thoracic spine. Treatment included posterior decompression (T1-T2 laminectomy) and percutaneous pedicle screw fixation at the C7-T4 level. Six months after surgery, the patient could walk with a cane, and the vertebral bodies T1-T2 were bridged without bone grafting. For thoracic spondylotic myelopathy associated with diffuse idiopathic skeletal hyperostosis, decompression and percutaneous pedicle screw fixation are effective therapies.

scholarly journals Posterior thoracolumbar hemivertebra resection and short-segment fusion in congenital scoliosis: surgical outcomes and complications with more than 5-year follow-up

BMC Surgery ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Beixi Bao ◽  
Qingjun Su ◽  
Yong Hai ◽  
Peng Yin ◽  
Yaoshen Zhang ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Surgical Outcomes ◽  
Screw Fixation ◽  
Congenital Scoliosis ◽  
Pedicle Screw Fixation ◽  
Rigid Fixation ◽  
Short Segment ◽  
Hemivertebra Resection ◽  
Main Curve

Abstract Background Treatment of congenital hemivertebra is challenging and data on long-term follow-up (≥ 5 years) are lacking. This study evaluated the surgical outcomes of posterior thoracolumbar hemivertebra resection and short-segment fusion with pedicle screw fixation for treatment of congenital scoliosis with over 5-year follow-up. Methods This study evaluated 27 consecutive patients with congenital scoliosis who underwent posterior thoracolumbar hemivertebra resection and short-segment fusion from January 2007 to January 2015. Segmental scoliosis, total main scoliosis, compensatory cranial curve, compensatory caudal curve, trunk shift, shoulder balance, segmental kyphosis, and sagittal balance were measured on radiographs. Radiographic outcomes and all intraoperative and postoperative complications were recorded. Results The segmental main curve was 40.35° preoperatively, 11.94° postoperatively, and 13.24° at final follow-up, with an average correction of 65.9%. The total main curve was 43.39° preoperatively, 14.13° postoperatively, and 16.06° at final follow-up, with an average correction of 60.2%. The caudal and cranial compensatory curves were corrected from 15.78° and 13.21° to 3.57° and 6.83° postoperatively and 4.38° and 7.65° at final follow-up, with an average correction of 69.2% and 30.3%, respectively. The segmental kyphosis was corrected from 34.30° to 15.88° postoperatively and 15.12° at final follow-up, with an average correction of 61.9%. A significant correction (p < 0.001) in segmental scoliosis, total main curve, caudal compensatory curves and segmental kyphosis was observed from preoperative to the final follow-up. The correction in the compensatory cranial curve was significant between preoperative and postoperative and 2-year follow-up (p < 0.001), but a statistically significant difference was not observed between the preoperative and final follow-up (p > 0.001). There were two implant migrations, two postoperative curve progressions, five cases of proximal junctional kyphosis, and four cases of adding-on phenomena. Conclusion Posterior thoracolumbar hemivertebra resection after short-segment fusion with pedicle screw fixation in congenital scoliosis is a safe and effective method for treatment and can achieve rigid fixation and deformity correction.

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