scholarly journals Biomechanical comparison between titanium and cobalt chromium rods used in a pedicle subtraction osteotomy model

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Kalpit N. Shah ◽  
Gregory Walker ◽  
Sarath C. Koruprolu ◽  
Alan H. Daniels
Keyword(s):  
Corrective Osteotomy ◽  
Deformity Correction ◽  
Pedicle Subtraction Osteotomy ◽  
Osteotomy Site ◽  
Cobalt Chromium ◽  
Hardware Failure ◽  
Spinal Reconstruction ◽  
Instrumentation Failure ◽  
Biomechanical Comparison ◽  
Rod Fracture

Instrumentation failure is a common complication following complex spinal reconstruction and deformity correction. Rod fracture is the most frequent mode of hardware failure and often occurs at or near a 3-column osteotomy site. Titanium (Ti) rods are commonly utilized for spinal fixations, however, theoretically stiffer materials, such as cobalt-chrome (CoCr) rods are also available. Despite ongoing use in clinical practice, there is little biomechanical evidence that compares the construct ability to withstand fatigue stress for Ti and Co-Cr rods. Six models using 2 polyethylene blocks each were used to simulate a pedicle subtraction osteotomy. Within each block 6.0×45 mm polyaxial screws were placed and connected to another block using either two 6.0×100 mm Ti (3 models) or CoCr rods (3 models). The rods were bent to 40° using a French bender and were secured to the screws to give a vertical height of 1.5 cm between the blocks. The blocks were fatigue tested with 700N at 4 Hz until failure. The average number of cycles to failure for the Ti rod models was 12840 while the CoCr rod models failed at a significantly higher, 58351 cycles (P=0.003). All Ti models experienced rod fracture as the mode of failure. Two out of the three CoCr models had rod fractures while the last sample failed via screw fracture at the screw-tulip junction. The risk of rod failure is substantial in the setting of long segment spinal arthrodesis and corrective osteotomy. Efforts to increase the mechanical strength of posterior constructs may reduce the occurrence of this complication. Utilizing CoCr rods in patients with pedicle subtraction osteotomy may reduce the rate of device failure during maturation of the posterior fusion mass and limit the need for supplemental anterior column support.

scholarly journals ЕFFECTIVENESS OF FOUR-ROD FIXATION FOR PEDICLE SUBTRACTION SPINAL OSTEOTOMY

2018 ◽  
Vol 24 (3) ◽  
pp. 65-73
Author(s):  
A. A. Panteleyev ◽  
S. P. Mironov ◽  
K. M. Buhtin ◽  
M. L. Sazhnev ◽  
A. I. Kazmin ◽  
...  
Keyword(s):  
Average Length ◽  
Pedicle Subtraction Osteotomy ◽  
Infectious Complications ◽  
Osteotomy Site ◽  
Fracture Rate ◽  
Spinopelvic Parameters ◽  
Lumbar Level ◽  
Ct Data ◽  
Rod Fracture

Introduction.Pedicle subtraction osteotomy (PSO) provides for significant segmental correction of the sagittalbalance of the spine. At the same time, the technique is associated with a high risk of complications, with rod fracture at the osteotomy site being the most common. The purposeof this study — to assess the effectiveness of four-rod fixation compared to literature data on standardtwo-rod fixation in patients undergoing PSO. Materials and Methods.The study is a retrospective analysis of 47 consecutive patients with rigid spinaldeformities, who underwent pedicle subtraction osteotomy at the lumbar level. The average age of the patients (33 females and 14 males) was 59.7 years. In all cases spinal fixation carried out using a four-rod construct with additional short rods at the osteotomy site. The minimal postoperative follow-up was 2 years. A detailed analysis of the radiographic data was carried out with calculation of the global sagittal balance and spinopelvic parameters. A detailed assessment of complications in the early and late postoperative periods was also performed. After an exhaustive review of literature, a comparative analysis was made of the four-rod fixation technique with current literature data on the frequency of complications (in particular, rod fractures in the osteotomy zone) after two-rod fixation. Results.In all cases the osteotomy was performed at one level, most often at L3 (49%). The average length offixation was 9.8 segments. The average angle of segmental correction was 27.1°. In most cases, it was possible to achieve adequate correction of spinopelvic parameters. Among complications, bone resorption around screws was most prevalent (23.4% of cases). Proximal junctional kyphosis occurred in 12.8% of cases, neurologic deficit — in 14.9% of cases, infectious complications — in 10.6% cases. Asymptomatic pseudarthrosis, confirmed by CT data, was observed in 12.8% of patients. Rod fracture at the PSO site and adjacent segments was not observed in any of the cases. Rod fractures of other localization were observed in 10.6% of patients. Conclusion. According to the literature, the frequency of rod fractures at the osteotomy site is the most frequentcomplication of PSO. The results of this study showed that four-rod fixation in PSO significantly reduces the incidence of pseudarthrosis and rod fracture rate in the long-term follow-up and provides greater control over the process of osteotomy closure.

Cross-link is a risk factor for rod fracture at pedicle subtraction osteotomy site: A finite element study

2019 ◽  
Vol 66 ◽  
pp. 246-250 ◽  
Author(s):  
Tae Hyun Park ◽  
Su Heon Woo ◽  
Sung Jae Lee ◽  
Dong Min Sohn ◽  
Chun Kee Chung ◽  
...  
Keyword(s):  
Finite Element ◽  
Risk Factor ◽  
Pedicle Subtraction Osteotomy ◽  
Osteotomy Site ◽  
Cross Link ◽  
Finite Element Study ◽  
Rod Fracture ◽  
Element Study

Spondylolisthesis following a pedicle subtraction osteotomy

2010 ◽  
Vol 28 (3) ◽  
pp. E16 ◽  
Author(s):  
Cheerag D. Upadhyaya ◽  
Sigurd Berven ◽  
Praveen V. Mummaneni
Keyword(s):  
Sagittal Plane ◽  
Deformity Correction ◽  
Pedicle Subtraction Osteotomy ◽  
Pedicle Screw Fixation ◽  
History Of ◽  
Plane Deformity ◽  
Correction Surgery ◽  
Flat Back ◽  
Rod Fracture ◽  
Rare Instance

Pedicle subtraction osteotomy (PSO) is a powerful technique for correcting a fixed sagittal plane deformity. The authors report the case of a 51-year-old man with a history of multiple prior lumbar operations, flat-back syndrome, thoracic kyphosis, and radiculopathy, who underwent deformity correction surgery with T3–S1 pedicle screw fixation and L-3 PSO. Progressive spondylolisthesis of the PSO segment associated with rod fracture then developed. The patient subsequently underwent anterior and posterior revision surgery. This case is a rare instance of spondylolisthesis following PSO.

scholarly journals Sagittal Deformity Correction in a Patient Suffering From Diffuse Idiopathic Skeletal Hyperostosis Who Previously Underwent a Total Hip and Bilateral Knee Replacement

2021 ◽  
Vol 12 ◽  
pp. 215145932199274
Author(s):  
Victor Garcia-Martin ◽  
Ana Verdejo-González ◽  
David Ruiz-Picazo ◽  
José Ramírez-Villaescusa
Keyword(s):  
Knee Replacement ◽  
Spinal Deformity ◽  
Diffuse Idiopathic Skeletal Hyperostosis ◽  
Deformity Correction ◽  
Pedicle Subtraction Osteotomy ◽  
Lower Limbs ◽  
Sagittal Imbalance ◽  
Total Hip ◽  
Correction Technique ◽  
Compensation Mechanisms

Introduction: Physiological aging frequently leads to degenerative changes and spinal deformity. In patients with hypolordotic fusions or ankylosing illnesses such as diffuse idiopathic skeletal hyperostosis or ankylosing spondylitis, compensation mechanisms can be altered causing severe pain and disability. In addition, if a total hip replacement and/or knee replacement is performed, both pelvic and lower limbs compensation mechanisms could be damaged and prosthetic dislocation or impingement syndrome could be present. Pedicle subtraction osteotomy has proven to be the optimal correction technique for spinal deformation in patients suffering from a rigid spine. Case Presentation: A 70-year-old male patient with diffuse idiopathic skeletal hyperostosis criteria and a rigid lumbar kyphosis, who previously underwent a total hip and knee replacement, had severe disability. We then performed corrective surgery by doing a pedicle subtraction osteotomy. The procedure and outcomes are presented here. Conclusion: In symptomatic patients with sagittal imbalance and a rigid spine, pedicle subtraction osteotomy can indeed correct spinal deformity and re-establish sagittal balance.

Strategies for prevention of rod fracture in adult spinal deformity: cobalt chrome rod, accessory rod technique, and lateral lumbar interbody fusion

2021 ◽  
pp. 1-10
Author(s):  
Ki Young Lee ◽  
Jung-Hee Lee ◽  
Kyung-Chung Kang ◽  
Sang-Kyu Im ◽  
Hae Seong Lim ◽  
...  
Keyword(s):  
Spinal Deformity ◽  
Interbody Fusion ◽  
Sagittal Alignment ◽  
Adult Spinal Deformity ◽  
Deformity Correction ◽  
Lumbar Interbody Fusion ◽  
Patient Factors ◽  
Rod Fracture ◽  
Cobalt Chrome

OBJECTIVERestoring the proper sagittal alignment in adult spinal deformity (ASD) can improve radiological and clinical outcomes, but pseudarthrosis including rod fracture (RF) is a common problematic complication. The purpose of this study was to analyze the methods for reducing the incidence of RF in deformity correction of ASD.METHODSThe authors retrospectively selected 178 consecutive patients (mean age 70.8 years) with lumbar degenerative kyphosis (LDK) who underwent deformity correction with a minimum 2-year follow-up. Patients were classified into the non-RF group (n = 131) and the RF group (n = 47). For predicting the crucial factors of RF, patient factors, radiographic parameters, and surgical factors were analyzed.RESULTSThe overall incidence of RF was 26% (47/178 cases), occurring in 42% (42/100 cases) of pedicle subtraction osteotomy (PSO), 7% (5/67 cases) of lateral lumbar interbody fusion (LLIF) with posterior column osteotomy, 18% (23/129 cases) of cobalt chrome rods, 49% (24/49 cases) of titanium alloy rods, 6% (2/36 cases) placed with the accessory rod technique, and 32% (45/142 cases) placed with the 2-rod technique. There were no significant differences in the incidence of RF regarding patient factors between two groups. While both groups showed severe sagittal imbalance before operation, lumbar lordosis (LL) was more kyphotic and pelvic incidence (PI) minus LL (PI-LL) mismatch was greater in the RF group (p < 0.05). Postoperatively, while LL and PI-LL did not show significant differences between the two groups, LL and sagittal vertical axis correction were greater in the RF group (p < 0.05). Nonetheless, at the last follow-up, the two groups did not show significant differences in radiographic parameters except thoracolumbar junctional angles. As for surgical factors, use of the cobalt chrome rod and the accessory rod technique was significantly greater in the non-RF group (p < 0.05). As for the correction method, PSO was associated with more RFs than the other correction methods, including LLIF (p < 0.05). By logistic regression analysis, PSO, preoperative PI-LL mismatch, and the accessory rod technique were crucial factors for RF.CONCLUSIONSGreater preoperative sagittal spinopelvic malalignment including preoperative PI-LL mismatch was the crucial risk factor for RF in LDK patients 65 years or older. For restoring and maintaining sagittal alignment, use of the cobalt chrome rod, accessory rod technique, or LLIF was shown to be effective for reducing RF in ASD surgery.

scholarly journals Stand-Alone Rod Augmentation for Instrumentation Failure after Pedicle Subtraction Osteotomy: A Case Report with a 2-year Follow-up

2021 ◽  
Author(s):  
Mohammad Zarei ◽  
Mohsen Rostami ◽  
Furqan Mohammed Yaseen Khan
Keyword(s):  
Case Report ◽  
Spine Surgery ◽  
Callus Tissue ◽  
Scar Tissue ◽  
Pedicle Subtraction Osteotomy ◽  
Lumbar Pain ◽  
Sagittal Imbalance ◽  
Complex Procedure ◽  
Instrumentation Failure

Background: Revision surgery of spine can be a complex procedure and has known complications. It involves hardware revision, removal of scar/callus tissue, realignment of sagittal balance, and anterior augmentation. However, through this report, we aim to demonstrate that a stand-alone rod augmentation at the failure site without removal of scar/callus tissue and/or anterior fixation can achieve excellent results in select cases. Case Report: A 66-year-old woman underwent L2 pedicle subtraction osteotomy (PSO) + T9-iliac fixation for fixed sagittal imbalance and osteoporotic collapse of L3. One year later, she developed progressive axial lumbar pain and difficulty in mobilization. The patient was diagnosed with pseudoarthrosis and instrumentation failure and underwent revision spine surgery with stand-alone rod augmentation. She had anuneventful rehabilitation and showed complete radiographic union and excellent clinical outcome in the 2-year follow-up. Conclusion: Stand-alone rod augmentation can provide stable posterior construct to prevent future pseudoarthrosis and/or instrumentation failure after revision spine surgery in selected cases. Anterior augmentation or resection dural scar tissue or dissection through callus tissue is not always necessary.  

Vertebral Column Resection (VCR) & Pedicle Subtraction Osteotomy (PSO) in Spinal Deformity Correction in Adult Patients 60 Years & Older

2011 ◽  
Vol 11 (10) ◽  
pp. S173
Author(s):  
Hamid Hassanzadeh ◽  
Amit Jain ◽  
Mostafa El Dafrawy ◽  
Addisu Mesfin ◽  
Richard Skolasky ◽  
...  
Keyword(s):  
Spinal Deformity ◽  
Vertebral Column ◽  
Deformity Correction ◽  
Pedicle Subtraction Osteotomy ◽  
Adult Patients ◽  
Vertebral Column Resection

scholarly journals Four-rod Technique Stabilization after Pedicle Subtraction Osteotomy (PSO) for the Treatment of Thoracolumbar Hyperkyphosis Secondary to Pott Disease: A Two-Year Follow-Up Case Report

2019 ◽  
Vol 38 (03) ◽  
pp. 219-226
Author(s):  
Alecio Cristino Evangelista Santos Barcelos ◽  
Sterphany Ohana Soares Azevedo Pinto ◽  
Thaise Ellen de Moura Agra Teixeira ◽  
Rayana Ellen Fernandes Nicolau
Keyword(s):  
Quality Of Life ◽  
Case Report ◽  
Short Form ◽  
Spinal Tuberculosis ◽  
Pedicle Subtraction Osteotomy ◽  
High Rate ◽  
Hardware Failure ◽  
Sf 36

AbstractPedicle subtraction osteotomy (PSO) is a powerful tool for the management of sagittal misalignment. However, this procedure has a high rate of implant failure, particularly rod breakages. The four-rod technique diminishes this complication in the lumbar spine. The aim of the present study is to provide a case report regarding PSO and four-rod technique stabilization in the treatment of short-angle hyperkyphosis in the thoracolumbar (TL) junction. The authors describe the case of a patient with TL hyperkyphosis secondary to spinal tuberculosis treated with L1 PSO and fixation with a four-rod technique. There were no major surgical complications. The self-reported quality of life questionnaires (the Short-Form Health Survey 36 [SF-36] and the Oswestry disability index) and radiological parameters were assessed preoperatively, as well as 6, 12 and 24 months after surgery, and they showed considerable and sustained improvements in pain control and quality of life. No hardware failure was observed at the two-year follow-up.

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