scholarly journals Complications associated with the Dynesys dynamic stabilization system: a comprehensive review of the literature

2016 ◽  
Vol 40 (1) ◽  
pp. E2 ◽  
Author(s):  
Martin H. Pham ◽  
Vivek A. Mehta ◽  
Neil N. Patel ◽  
Andre M. Jakoi ◽  
Patrick C. Hsieh ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Lumbar Fusion ◽  
Dynamic Stabilization ◽  
Adjacent Segment ◽  
Fracture Rate ◽  
Complication Rates ◽  
Stabilization System ◽  
Lumbar Degenerative Disease ◽  
Rate Profile ◽  
Pedicle Screw Loosening

The Dynesys dynamic stabilization system is an alternative to rigid instrumentation and fusion for the treatment of lumbar degenerative disease. Although many outcomes studies have shown good results, currently lacking is a comprehensive report on complications associated with this system, especially in terms of how it compares with reported complication rates of fusion. For the present study, the authors reviewed the literature to find all studies involving the Dynesys dynamic stabilization system that reported complications or adverse events. Twenty-one studies were included for a total of 1166 patients with a mean age of 55.5 years (range 39–71 years) and a mean follow-up period of 33.7 months (range 12.0–81.6 months). Analysis of these studies demonstrated a surgical-site infection rate of 4.3%, pedicle screw loosening rate of 11.7%, pedicle screw fracture rate of 1.6%, and adjacent-segment disease (ASD) rate of 7.0%. Of studies reporting revision surgeries, 11.3% of patients underwent a reoperation. Of patients who developed ASD, 40.6% underwent a reoperation for treatment. The Dynesys dynamic stabilization system appears to have a fairly similar complication-rate profile compared with published literature on lumbar fusion, and is associated with a slightly lower incidence of ASD.

Adjacent-segment effects of lumbar cortical screw–rod fixation versus pedicle screw–rod fixation with and without interbody support

2021 ◽  
pp. 1-7
Author(s):  
Piyanat Wangsawatwong ◽  
Anna G. U. Sawa ◽  
Bernardo de Andrada Pereira ◽  
Jennifer N. Lehrman ◽  
Luke K. O’Neill ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Interbody Fusion ◽  
Lumbar Fusion ◽  
Statistical Significance ◽  
Adjacent Segment ◽  
Lumbar Interbody Fusion ◽  
Lateral Bending ◽  
Single Level ◽  
Cortical Screw ◽  
Flexion Extension

OBJECTIVE Cortical screw–rod (CSR) fixation has emerged as an alternative to the traditional pedicle screw–rod (PSR) fixation for posterior lumbar fixation. Previous studies have concluded that CSR provides the same stability in cadaveric specimens as PSR and is comparable in clinical outcomes. However, recent clinical studies reported a lower incidence of radiographic and symptomatic adjacent-segment degeneration with CSR. No biomechanical study to date has focused on how the adjacent-segment mobility of these two constructs compares. This study aimed to investigate adjacent-segment mobility of CSR and PSR fixation, with and without interbody support (lateral lumbar interbody fusion [LLIF] or transforaminal lumbar interbody fusion [TLIF]). METHODS A retroactive analysis was done using normalized range of motion (ROM) data at levels adjacent to single-level (L3–4) bilateral screw–rod fixation using pedicle or cortical screws, with and without LLIF or TLIF. Intact and instrumented specimens (n = 28, all L2–5) were tested using pure moment loads (7.5 Nm) in flexion, extension, lateral bending, and axial rotation. Adjacent-segment ROM data were normalized to intact ROM data. Statistical comparisons of adjacent-segment normalized ROM between two of the groups (PSR followed by PSR+TLIF [n = 7] and CSR followed by CSR+TLIF [n = 7]) were performed using 2-way ANOVA with replication. Statistical comparisons among four of the groups (PSR+TLIF [n = 7], PSR+LLIF [n = 7], CSR+TLIF [n = 7], and CSR+LLIF [n = 7]) were made using 2-way ANOVA without replication. Statistical significance was set at p < 0.05. RESULTS Proximal adjacent-segment normalized ROM was significantly larger with PSR than CSR during flexion-extension regardless of TLIF (p = 0.02), or with either TLIF or LLIF (p = 0.04). During lateral bending with TLIF, the distal adjacent-segment normalized ROM was significantly larger with PSR than CSR (p < 0.001). Moreover, regardless of the types of screw-rod fixations (CSR or PSR), TLIF had a significantly larger normalized ROM than LLIF in all directions at both proximal and distal adjacent segments (p ≤ 0.04). CONCLUSIONS The use of PSR versus CSR during single-level lumbar fusion can significantly affect mobility at the adjacent segment, regardless of the presence of TLIF or with either TLIF or LLIF. Moreover, the type of interbody support also had a significant effect on adjacent-segment mobility.

scholarly journals Novel placement of cortical bone trajectory screws in previously instrumented pedicles for adjacent-segment lumbar disease using CT image-guided navigation

2014 ◽  
Vol 36 (3) ◽  
pp. E9 ◽  
Author(s):  
Analiz Rodriguez ◽  
Matthew T. Neal ◽  
Ann Liu ◽  
Aravind Somasundaram ◽  
Wesley Hsu ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Lumbar Fusion ◽  
Pedicle Screw Fixation ◽  
Adjacent Segment ◽  
Average Hospital ◽  
Cortical Bone Trajectory ◽  
Image Guided

Object Symptomatic adjacent-segment lumbar disease (ASLD) after lumbar fusion often requires subsequent surgical intervention. The authors report utilizing cortical bone trajectory (CBT) pedicle screw fixation with intraoperative CT (O-arm) image-guided navigation to stabilize spinal levels in patients with symptomatic ASLD. This unique technique results in the placement of 2 screws in the same pedicle (1 traditional pedicle trajectory and 1 CBT) and obviates the need to remove preexisting instrumentation. Methods The records of 5 consecutive patients who underwent lumbar spinal fusion with CBT and posterior interbody grafting for ASLD were retrospectively reviewed. All patients underwent screw trajectory planning with the O-arm in conjunction with the StealthStation navigation system. Basic demographics, operative details, and radiographic and clinical outcomes were obtained. Results The average patient age was 69.4 years (range 58–82 years). Four of the 5 surgeries were performed with the Minimal Access Spinal Technologies (MAST) Midline Lumbar Fusion (MIDLF) system. The average operative duration was 218 minutes (range 175–315 minutes). In the entire cohort, 5.5-mm cortical screws were placed in previously instrumented pedicles. The average hospital stay was 2.8 days (range 2–3 days) and there were no surgical complications. All patients had more than 6 months of radiographic and clinical follow-up (range 10–15 months). At last follow-up, all patients reported improved symptoms from their preoperative state. Radiographic follow-up showed Lenke fusion grades of A or B. Conclusions The authors present a novel fusion technique that uses CBT pedicle screw fixation in a previously instrumented pedicle with intraoperative O-arm guided navigation. This method obviates the need for hardware removal. This cohort of patients experienced good clinical results. Computed tomography navigation was critical for accurate CBT screw placement at levels where previous traditional pedicle screws were already placed for symptomatic ASLD.

scholarly journals Severe Retrolisthesis at the Adjacent Segment after Lumbar Fusion Combined with Dynamic Stabilization

2017 ◽  
Vol 13 (1) ◽  
pp. 50
Author(s):  
Min Chan Kim ◽  
Hui Sun Wang ◽  
Chang Il Ju ◽  
Seok Won Kim
Keyword(s):  
Lumbar Fusion ◽  
Dynamic Stabilization ◽  
Adjacent Segment

scholarly journals Mid-range outcomes in 64 consecutive cases of multilevel fusion for degenerative diseases of the lumbar spine

2010 ◽  
Vol 2 (1) ◽  
pp. 3 ◽  
Author(s):  
Marc Röllinghoff ◽  
Klaus Schlüter-Brust ◽  
Daniel Groos ◽  
Rolf Sobottke ◽  
Joern William-Patrick Michael ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Clinical Outcomes ◽  
Adjacent Segment Disease ◽  
Adjacent Segment ◽  
Screw Loosening ◽  
Flexion Extension ◽  
Multilevel Fusion ◽  
Pedicle Screw Loosening

In the treatment of multilevel degenerative disorders of the lumbar spine, spondylodesis plays a controversial role. Most patients can be treated conservatively with success. Multilevel lumbar fusion with instrumentation is associated with severe complications like failed back surgery syndrome, implant failure, and adjacent segment disease (ASD). This retrospective study examines the records of 70 elderly patients with degenerative changes or instability of the lumbar spine treated between 2002 and 2007 with spondylodesis of more than two segments. Sixty-four patients were included; 5 patients had died and one patient was lost to follow-up. We evaluated complications, clinical/radiological outcomes, and success of fusion. Flexion-extension and standing X-rays in two planes, MRI, and/or CT scans were obtained pre-operatively. Patients were assessed clinically using the Oswestry disability index (ODI) and a Visual Analogue Scale (VAS). Surgery performed was dorsolateral fusion (46.9%) or dorsal fusion with anterior lumbar interbody fusion (ALIF; 53.1%). Additional decompression was carried out in 37.5% of patients. Mean follow-up was 29.4±5.4 months. Average patient age was 64.7±4.3 years. Clinical outcomes were not satisfactory for all patients. VAS scores improved from 8.6±1.3 to 5.6±3.0 pre- to post-operatively, without statistical significance. ODI was also not significantly improved (56.1±22.3 pre- and 45.1±26.4 post-operatively). Successful fusion, defined as adequate bone mass with trabeculation at the facets and transverse processes or in the intervertebral segments, did not correlate with good clinical outcomes. Thirty-five of 64 patients (54%) showed signs of pedicle screw loosening, especially of the screws at S1. However, only 7 of these 35 (20%) complained of corresponding back pain. Revision surgery was required in 24 of 64 patients (38%). Of these, indications were adjacent segment disease (16 cases), pedicle screw loosening (7 cases), and infection (one case). At follow-up of 29.4 months, patients with radiographic ASD had worse ODI scores than patients without (54.7 vs. 36.6; P less than 0.001). Multilevel fusion for degenerative disease still has a high rate of complications, up to 50%. The problem of adjacent segment disease after fusion surgery has not yet been solved. This study underscores the need for strict indication guidelines to perform lumbar spine fusion of more than two levels.

Letter to the Editor: Pedicle screw–based dynamic stabilization and adjacent-segment disease

2017 ◽  
Vol 26 (3) ◽  
pp. 405-406 ◽  
Author(s):  
Yu-Wen Cheng ◽  
Peng-Yuan Chang ◽  
Jau-Ching Wu ◽  
Chih-Chang Chang ◽  
Li-Yu Fay ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Dynamic Stabilization ◽  
Adjacent Segment Disease ◽  
Adjacent Segment ◽  
Letter To The Editor

scholarly journals Durability and Biological Response of a New Posterior Dynamic Stabilization System Using Polyethylene with Vitamin E

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Koji Matsumoto ◽  
Yasuaki Tokuhashi
Keyword(s):  
Vitamin E ◽  
Pedicle Screw ◽  
Inflammatory Cell ◽  
Facet Joint ◽  
Biological Response ◽  
Dynamic Stabilization ◽  
Inflammatory Cell Infiltration ◽  
Stabilization System ◽  
Sliding Surface ◽  
Posterior Dynamic Stabilization

Objective. The purpose of this study was to evaluate the durability and biological response of a new Posterior Dynamic Stabilization system using polyethylene with vitamin E on the sliding surface. Summary of Background Data. The use of polyethylene with vitamin E on the sliding surface in Posterior Dynamic Stabilization has not been reported previously. Methods. A developed pedicle screw-based Posterior Dynamic system consists of four parts: a set screw, a rod, a ball, and a pedicle screw. The rod is inserted into the through hole of the ball, and the ball is sandwiched by the set screw. (1) Fatigue Wear Test. Testing was conducted under a dynamic compressive load of 50N at a speed of 1 Hz for 1 million cycles. We examined the loss of polyethylene due to abrasion in 3 units. (2) Biological Response in Pigs. In two pigs, a new pedicle screw and a conventional pedicle screw were inserted in L2 and L3/4, and L4 and L2/3, respectively. After breeding for 6 months, autopsies were performed. CT imaging was used to evaluate bone union of the facet joint. Abrasive specimens were prepared, and abrasion powder and inflammatory cell infiltration were evaluated microscopically. Results. The average loss of polyethylene due to abrasion was -0.01 mg. In all units, polyethylene showed a decrease of 0.1 mm or less at the contact point with the set screw. The facet joints between the conventional screws exhibited bone fusion, but the facet joint between the conventional and the new screw retained mobility with no bony fusion. No abrasion powder was found and inflammatory cell infiltration was only minimally observed. Conclusion. The new Posterior Dynamic Stabilization system exhibited a high level of durability and biological safety.

scholarly journals Intraoperative biomechanics of lumbar pedicle screw loosening following successful arthrodesis

2016 ◽  
Author(s):  
Hope B. Pearson ◽  
Christopher J. Dobbs ◽  
Eric Grantham ◽  
Glen L. Niebur ◽  
James L. Chappuis ◽  
...  
Keyword(s):  
Back Pain ◽  
Pedicle Screw ◽  
Statistical Power ◽  
Lumbar Fusion ◽  
Pedicle Screws ◽  
Screw Loosening ◽  
Screw Insertion ◽  
Screw Misplacement ◽  
Lumbar Spinal ◽  
Pedicle Screw Loosening

AbstractPedicle screw loosening has been implicated in recurrent back pain after lumbar spinal fusion, but the degree of loosening has not been systematically quantified in patients. Instrumentation removal is an option for patients with successful arthrodesis, but remains controversial. Here, we quantified pedicle screw loosening by measuring screw insertion and/or removal torque at high statistical power (β = 0.98) in N = 108 patients who experienced pain recurrence despite successful fusion after posterior instrumented lumbar fusion with anterior lumbar interbody fusion (L2-S1). Between implantation and removal, pedicle screw torque was reduced by 58%, indicating significant loosening over time. Loosening was greater in screws with evoked EMG threshold under 11 mA, indicative of screw misplacement. A theoretical stress analysis revealed increased local stresses at the screw interface in pedicles with decreased difference in pedicle thickness and screw diameter. Loosening was greatest in vertebrae at the extremities of the fused segments, but was significantly lower in segments with one level of fusion than in those with two or more.Clinical significanceThese data indicate that pedicle screws can loosen significantly in patients with recurrent back pain and warrant further research into methods to reduce the incidence of screw loosening and to understand the risks and potential benefits of instrumentation removal.

scholarly journals Does Percutaneous Lumbosacral Pedicle Screw Instrumentation Prevent Long-Term Adjacent Segment Disease after Lumbar Fusion?

2020 ◽  
Author(s):  
Stuart Changoor ◽  
Michael Joseph Faloon ◽  
Conor John Dunn ◽  
Nikhil Sahai ◽  
Kimona Issa ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Lumbar Fusion ◽  
Adjacent Segment Disease ◽  
Adjacent Segment ◽  
Pedicle Screw Instrumentation
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