scholarly journals Rod stiffness effect on adjacent segmental degeneration: a comparative long-term study

2010 ◽  
Vol 4 (4) ◽  
pp. 579-584
Author(s):  
Prakit Tienboon ◽  
Nara Jaruwangsanti
Keyword(s):  
Lumbar Spine ◽  
Posterior Instrumentation ◽  
Spinal Instrumentation ◽  
Major Complication ◽  
Close Correlation ◽  
Adjacent Segment ◽  
X Rays ◽  
Spinal Implant ◽  
Long Term Study ◽  
Asymptomatic Patients

Abstract Background: Adjacent segment disease (ASD) is a major complication following spinal instrumentation and fusion. The search for of the rod flexibility factors responsible for junctional degeneration is still ongoing. Objective: Determine the rod stiffness and ASD following posterior instrumentation and fusion for lumbar spine and find the proper rod diameter for adult spinal instrumentation for fusion. Subject and methods: Retrospective evaluation of all patients requiring spinal instrumentation to determine the different rod diameter that predispose toward junctional degeneration was completed. All patients requiring spinal instrumentation over a one-year period were studied retrospectively. One-hundred eight-seven patients (mean age 61.6 years) who had undergone decompression and fusion with pedicle screw instrumentation were evaluated. The average follow-up was 4.2 years. The average number of levels fused was 2.9 segments (range: 1-8). Adjacent spinal level pre- and post-operatively was determined on the plain X-rays. Junctional degeneration was defined as new episode of degeneration of the adjacent level on radiologic finding. Asymptomatic patients did not demonstrate junctional degeneration on the routine post-operative X-rays. Results: ASD developed in 15 (8.0%) out of 187 patients, including compression fractures (n=2), spinal stenosis (n=6), and symptomatic disc collapse (n=7). There was a close correlation between the posterior instrument stiffness and the development of ASD (p=0.011). For fusion and fixation with 5.5 mm and 6.0 mm rod diameter, ASD occurred in four (3.7%) out of 108 patients and in 11 (13.9 %) out of 79 patients, resepectively. The incidences of ASD were greater when the posterior instrument used were stiffer in lumbar spine fusion. The pre-operative age, gender, and indication for surgery were not associated with the development of ASD. Conclusion: The prevalence of symptomatic ASD relatively increased with increasing stiffness of spinal implant. The diameter of the longitudinal rod strongly affected the fixator loads, and influenced the stresses in the vertebral endplates. The rod diameter had influence on the stresses in the adjacent spinal motion segment.

scholarly journals Placement of Unilateral Cortical Bone Trajectory Screws in Previously Instrumented Pedicle without Removal of Existing Hardware for Adjacent Segment Disease

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Rojeh Melikian ◽  
Sofia Yeremian
Keyword(s):  
United States ◽  
Case Report ◽  
Lumbar Spine ◽  
Posterior Instrumentation ◽  
Treatment Options ◽  
Pedicle Screws ◽  
The United States ◽  
Infection Risk ◽  
Adjacent Segment Disease ◽  
Adjacent Segment

Adjacent segment disease (ASD) in the lumbar spine is a possible consequence in segments adjacent to a fusion. As the number of lumbar fusions in the United States increases, the rates of ASD will continue to climb. There are several treatment options for ASD with open decompression and extension of the fusion being common. However, need for exposure and removal of existing instrumentation can lead to increased operative times resulting in increasing blood loss and infection risk. The purpose of this paper is to describe a case report for unilateral cortical trajectory screw instrumentation, allowing for posterior instrumentation without having to remove the existing pedicle screws in the setting of ASD. Our technique can be done with standard c-arm fluoroscopy without the need for navigation.

scholarly journals Use of Nitinol Rods for Lumbosacral Spine Fixation (Prospective Randomized Clinical Study)

2014 ◽  
Vol 21 (2) ◽  
pp. 19-24
Author(s):  
S. V Kolesov ◽  
V. V Shvets ◽  
D. A Kolobovskiy ◽  
A. I Kaz’min ◽  
N. S Morozova
Keyword(s):  
Lumbar Spine ◽  
Group Formation ◽  
Lumbosacral Spine ◽  
Adjacent Segment ◽  
Rigid Fixation ◽  
X Rays ◽  
Randomized Clinical Study ◽  
Spine Diseases ◽  
Spine Fixation ◽  
Group 1

One hundred thirty operations were performed in patients (57 males, 73 females) with degenerative lumbar spine diseases during the period from 2010 to 2012. Mean age of patients made up 57 (45-82) years. Depending on the type of intervention all patients were divided into 2 groups: in 60patients (1 st group) dynamic stabilization with nitinol rods without fusion and in 70patients (2 nd group) rigid fixation of lumbar spine with titanium rods was performed. Outcomes were analyzed in 1.5 years after surgery. VAS, ODI and SF36 questionnaires showed improvement of patients’ condition in both groups. Restoration of lordosis was from 22 to 35° and from 23 to 37° in 1 st and 2 nd groups, respectively. No screw instability, bone tissue resorption around the screws and adjacent segment pathology was noted in group 1. Functional X-rays showed preservation of mobility (5+1.2°). In 2 nd group formation of pseudarthrosis was recorded in 5patients, adjacent segment pathology - in 20 including 5 patients who required repeated surgical intervention. Transpedicular lumbosacral spine fixation using nitinol rods is an effective technique that enables to preserve movements in lumbosacral spine in combination with stable fixation

scholarly journals Adjacent segment disease in degenerative pathologies with posterior instrumentation

2015 ◽  
Vol 14 (1) ◽  
pp. 23-26 ◽  
Author(s):  
Ana Guadalupe Ramírez Olvera ◽  
Manuel Villarreal Arroyo ◽  
Luis Mario Hinojosa Martínez ◽  
Enrique Méndez Pérez ◽  
Luis Romeo Ramos Hinojosa
Keyword(s):  
Lumbar Spine ◽  
Posterior Instrumentation ◽  
Degenerative Spondylolisthesis ◽  
Case Series ◽  
Adjacent Segment Disease ◽  
Diagnosis And Treatment ◽  
Adjacent Segment ◽  
Degenerative Scoliosis ◽  
Radiographic Findings ◽  
Case Series Study

OBJECTIVE: To establish the real incidence of adjacent segment disease after fusion, and to identify the levels and predisposing factors for the pathology, as well as the functional results. METHODS: a retrospective case series study with level of evidence IIB, in a sample of 179 patients diagnosed with stenosis of the lumbar spine, spondylolisthesis and degenerative scoliosis, submitted to surgery in the period 2005 to December 2013, with posterior instrumentation and posterolateral fusion, with follow-up from 2007 until May 2014, in which the symptomology and radiographic findings were evaluated, to establish the diagnosis and treatment. RESULTS: the study included 179 patients diagnosed with stenosis of the lumbar spine (n=116), isthmic and degenerative spondylolisthesis (n=50) and degenerative scoliosis (n=13); during the study, 20 cases of adjacent level segment were identified, 80% of which were treated surgically with extension of the instrumentation, while 20% were treated conservatively with NSAIDs and therapeutic blocks. CONCLUSION: An incidence of 11% was found, with an average of 3.25 years in diagnosis and treatment, a prevalence of females and diagnosis of stenosis of the lumbar canal on posterior instrumentation, a predominance of levels L4-L5; 80% were treated with extension of the instrumentation. The complications were persistent radiculopathy, infection of the surgical wound, and one death due to causes not related to the lumbar pathology.

Biomechanical Analysis of a Long-Segment Fusion in a Lumbar Spine—A Finite Element Model Study

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Raghu N. Natarajan ◽  
Kei Watanabe ◽  
Kazuhiro Hasegawa
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Posterior Instrumentation ◽  
Spinal Instrumentation ◽  
Element Model ◽  
Biomechanical Analysis ◽  
Spinal Stabilization ◽  
Rod System ◽  
Fixation Techniques ◽  
Materials Used

Examine the biomechanical effect of material properties, geometric variables, and anchoring arrangements in a segmental pedicle screw with connecting rods spanning the entire lumbar spine using finite element models (FEMs). The objectives of this study are (1) to understand how different variables associated with posterior instrumentation affect the lumbar spine kinematics and stresses in instrumentation, (2) to compare the multidirectional stability of the spinal instrumentation, and (3) to determine how these variables contribute to the rigidity of the long-segment fusion in a lumbar spine. A lumbar spine FEM was used to analyze the biomechanical effects of different materials used for spinal rods (TNTZ or Ti or CoCr), varying diameters of the screws and rods (5 mm and 6 mm), and different fixation techniques (multilevel or intermittent). The results based on the range of motion and stress distribution in the rods and screws revealed that differences in properties and variations in geometry of the screw-rod moderately affect the biomechanics of the spine. Further, the spinal screw-rod system was least stable under the lateral bending mode. Stress analyzes of the screws and rods revealed that the caudal section of the posterior spinal instrumentation was more susceptible to high stresses and hence possible failure. Although CoCr screws and rods provided the greatest spinal stabilization, these constructs were susceptible to fatigue failure. The findings of the present study suggest that a posterior instrumentation system with a 5-mm screw-rod diameter made of Ti or TNTZ is advantageous over CoCr instrumentation system.

Case Example: Adjacent Segment Disease: What Is It, and How Is It Rated?

2011 ◽  
Vol 16 (2) ◽  
pp. 8-9
Author(s):  
Marjorie Eskay-Auerbach
Keyword(s):  
Clinical Symptoms ◽  
Lumbar Fusion ◽  
Adjacent Segment Degeneration ◽  
Adjacent Segment Disease ◽  
Adjacent Segment ◽  
Disc Space Narrowing ◽  
Disc Disease ◽  
Disc Space ◽  
Radiographic Findings ◽  
Asymptomatic Patients

Abstract The incidence of cervical and lumbar fusion surgery has increased in the past twenty years, and during follow-up some of these patients develop changes at the adjacent segment. Recognizing that adjacent segment degeneration and disease may occur in the future does not alter the rating for a cervical or lumbar fusion at the time the patient's condition is determined to be at maximum medical improvement (MMI). The term adjacent segment degeneration refers to the presence of radiographic findings of degenerative disc disease, including disc space narrowing, instability, and so on at the motion segment above or below a cervical or lumbar fusion. Adjacent segment disease refers to the development of new clinical symptoms that correspond to these changes on imaging. The biomechanics of adjacent segment degeneration have been studied, and, although the exact mechanism is uncertain, genetics may play a role. Findings associated with adjacent segment degeneration include degeneration of the facet joints with hypertrophy and thickening of the ligamentum flavum, disc space collapse, and translation—but the clinical significance of these radiographic degenerative changes remains unclear, particularly in light of the known presence of abnormal findings in asymptomatic patients. Evaluators should not rate an individual in anticipation of the development of changes at the level above a fusion, although such a development is a recognized possibility.

scholarly journals Do Orthopedic Surgeons or Neurosurgeons Detect More Hip Disorders in Patients with Hip-Spine Syndrome? A Nationwide Database Study

2021 ◽  
Vol 11 (4) ◽  
pp. 485
Author(s):  
Tsung-Cheng Yin ◽  
Adam M. Wegner ◽  
Meng-Ling Lu ◽  
Yao-Hsu Yang ◽  
Yao-Chin Wang ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Spine Surgery ◽  
Hip Surgery ◽  
Lumbar Spine Surgery ◽  
Research Database ◽  
X Rays ◽  
Replacement Surgery ◽  
Orthopedic Surgeons ◽  
Spine Pathology ◽  
Sh Group

Background: Disorders of the hip and lumbar spine can create similar patterns of pain and dysfunction. It is unknown whether all surgeons, regardless of orthopedic or neurosurgery training, investigate and diagnose concurrent hip and spine pathology at the same rate. Methods: Data were retrieved from Taiwan’s National Health Insurance Research Database (NHIRD). Enrolled patients were stratified into hip and spine surgery at the same admission (Both), hip surgery before spine surgery (HS), or spine surgery before hip surgery (SH). The SH group was further subdivided based on whether spine surgery was performed by an orthopedic surgeon (OS) or neurosurgeon (NS), and differences in preoperative radiographic examinations and diagnoses were collected and analyzed. Results: In total, 1824 patients received lumbar spine surgery within 1 year before or after hip replacement surgery. Of these, 103 patients had spine and hip surgery in the same admission (Both), 1290 patients had spine surgery before hip surgery (SH), and 431 patients had hip surgery before spine surgery (HS). In the SH group, patients were categorized into spine surgery by orthopedic surgeons (OS) (n = 679) or neurosurgeons (NS) (n = 522). In the SH group, orthopedic surgeons investigated hip pathology with X-rays more often (52.6% vs. 38.1%, p < 0.001) and diagnosed more cases of hip disease (43.6% vs. 28.9%, p < 0.001) than neurosurgeons. Conclusions: Of patients in Taiwan’s NHIRD who had concurrent surgical degenerative hip and lumbar spine disorders who had spine surgery before hip surgery, orthopedic surgeons obtained hip images and made hip-related diagnoses more frequently than did neurosurgeons.

Outcomes of 2-level posterior lumbar interbody fusion for 2-level degenerative lumbar spondylolisthesis

2013 ◽  
Vol 19 (1) ◽  
pp. 90-94 ◽  
Author(s):  
Hironobu Sakaura ◽  
Tomoya Yamashita ◽  
Toshitada Miwa ◽  
Kenji Ohzono ◽  
Tetsuo Ohwada
Keyword(s):  
Lumbar Spine ◽  
Clinical Outcome ◽  
Interbody Fusion ◽  
Sagittal Alignment ◽  
Posterior Lumbar Interbody Fusion ◽  
Adjacent Segment ◽  
Lumbar Interbody Fusion ◽  
Single Level ◽  
The Mean

Object A systematic review concerning surgical management of lumbar degenerative spondylolisthesis (DS) showed that a satisfactory clinical outcome was significantly more likely with adjunctive spinal fusion than with decompression alone. However, the role of adjunctive fusion and the optimal type of fusion remain controversial. Therefore, operative management for multilevel DS raises more complicated issues. The purpose of this retrospective study was to elucidate clinical and radiological outcomes after 2-level PLIF for 2-level DS with the least bias in determination of operative procedure. Methods Since 2005, all patients surgically treated for lumbar DS at the authors' hospital have been treated using posterior lumbar interbody fusion (PLIF) with pedicle screws, irrespective of severity of slippage, patient age, or bone quality. The authors conducted a retrospective review of 20 consecutive cases involving patients who underwent 2-level PLIF for 2-level DS and had been followed up for 2 years or longer (2-level PLIF group). They also analyzed data from 92 consecutive cases involving patients who underwent single-level PLIF for single-level DS during the same time period and had been followed for at least 2 years (1-level PLIF group). This second group served as a control. Clinical status was assessed using the Japanese Orthopaedic Association (JOA) score. Fusion status and sagittal alignment of the lumbar spine were assessed by comparing serial plain radiographs. Surgery-related complications and the need for additional surgery were evaluated. Results The mean JOA score improved significantly from 12.8 points before surgery to 20.4 points at the latest follow-up in the 2-level PLIF group (mean recovery rate 51.8%), and from 14.2 points preoperatively to 22.5 points at the latest follow-up in the single-level PLIF group (mean recovery rate 55.3%). At the final follow-up, 95.0% of patients in the 2-level PLIF group and 96.7% of those in the 1-level PLIF group had achieved solid spinal fusion, and the mean sagittal alignment of the lumbar spine was more lordotic than before surgery in both groups. Early surgery-related complications, including transient neurological complications, occurred in 6 patients in the 2-level PLIF group (30.0%) and 11 patients in the 1-level PLIF group (12.0%). Symptomatic adjacent-segment disease was found in 4 patients in the 2-level PLIF group (20.0%) and 10 patients in the 1-level PLIF group (10.9%). Conclusions The clinical outcome of 2-level PLIF for 2-level lumbar DS was satisfactory, although surgery-related complications including symptomatic adjacent-segment disease were not negligible.

scholarly journals The Biological Effects of Combining Metals in a Posterior Spinal Implant: In Vivo Model Development Report of the First Two Cases

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Christine L. Farnsworth ◽  
Peter O. Newton ◽  
Eric Breisch ◽  
Michael T. Rohmiller ◽  
Jung Ryul Kim ◽  
...  
Keyword(s):  
Galvanic Corrosion ◽  
Biological Effects ◽  
Model Development ◽  
Spinal Instrumentation ◽  
Pedicle Screws ◽  
Tissue Response ◽  
In Vivo Model ◽  
Particle Count ◽  
Spinal Implant

Study Design. Combinations of metal implants (stainless steel (SS), titanium (Ti), and cobalt chrome (CC)) were placed in porcine spines. After 12 months, tissue response and implant corrosion were compared between mixed and single metal junctions. Objective. Model development and an attempt to determine any detriment of combining different metals in posterior spinal instrumentation. Methods. Yucatan mini-pigs underwent instrumentation over five unfused lumbar levels. A SS rod and a Ti rod were secured with Ti and SS pedicle screws, SS and Ti crosslinks, SS and CC sublaminar wires, and Ti sublaminar cable. The resulting 4 SS/SS, 3 Ti/Ti, and 11 connections between dissimilar metals per animal were studied after 12 months using radiographs, gross observation, and histology (foreign body reaction (FBR), metal particle count, and inflammation analyzed). Results. Two animals had constructs in place for 12 months with no complications. Histology of tissue over SS/SS connections demonstrated 11.1 ± 7.6 FBR cells, 2.1 ± 1.7 metal particles, and moderate to extensive inflammation. Ti/Ti tissue showed 6.3 ± 3.8 FBR cells, 5.2 ± 6.7 particles, and no to extensive inflammation (83% extensive). Tissue over mixed components had 14.1 ± 12.6 FBR cells and 13.4 ± 27.8 particles. Samples surrounding wires/cables versus other combinations demonstrated FBR (12.4 ± 13.5 versus 12.0 ± 9.6 cells, P = 0.96), particles (19.8 ± 32.6 versus 4.3 ± 12.7, P = 0.24), and inflammation (50% versus 75% extensive, P = 0.12). Conclusions. A nonfusion model was developed to study corrosion and analyze biological responses. Although no statistical differences were found in overlying tissue response to single versus mixed metal combinations, galvanic corrosion between differing metals is not ruled out. This pilot study supports further investigation to answer concerns when mixing metals in spinal constructs.

scholarly journals Prospective surgical solutions in degenerative spine: spinal simulation for optimal choice of implant and targeted device development

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Monique Salchow-Gille ◽  
Bernhard Rieger ◽  
Clemens Reinshagen ◽  
Marek Molcanyi ◽  
Joschka Lemke ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Functional Model ◽  
Neck Disability Index ◽  
Optimal Choice ◽  
Segmental Motion ◽  
X Rays ◽  
Device Development ◽  
Single Segment ◽  
Implant Selection ◽  
Adjacent Segments

Abstract Objectives The most important goal of surgical treatment for spinal degeneration, in addition to eliminating the underlying pathology, is to preserve the biomechanically relevant structures. If degeneration destroys biomechanics, the single segment must either be surgically stabilized or functionally replaced by prosthetic restoration. This study examines how software-based presurgical simulation affects device selection and device development. Methods Based on videofluoroscopic motion recordings and pixel-precise processing of the segmental motion patterns, a software-based surrogate functional model was validated. It characterizes the individual movement of spinal segments relative to corresponding cervical or lumbar spine sections. The single segment-based motion of cervical or lumbar spine of individual patients can be simulated, if size-calibrated functional X-rays of the relevant spine section are available. The software plug-in “biokinemetric triangle” has been then integrated into this software to perform comparative segmental motion analyses before and after treatment in two cervical device studies: the correlation of implant-induced changes in the movement geometry and patient-related outcome was examined to investigate, whether this surrogate model could provide a guideline for implant selection and future implant development. Results For its validation in 253 randomly selected patients requiring single-level cervical (n=122) or lumbar (n=131) implant-supported restoration, the biokinemetric triangle provided significant pattern recognition in comparable investigations (p<0.05) and the software detected device-specific changes after implant-treatment (p<0.01). Subsequently, 104 patients, who underwent cervical discectomy, showed a correlation of the neck disability index with implant-specific changes in their segmental movement geometry: the preoperative simulation supported the best choice of surgical implants, since the best outcome resulted from restricting the extent of the movement of adjacent segments influenced by the technical mechanism of the respective device (p<0.05). Conclusions The implant restoration resulted in best outcome which modified intersegmental communication in a way that the segments adjacent to the implanted segment undergo less change in their own movement geometry. Based on our software-surrogate, individualized devices could be created that slow down further degeneration of adjacent segments by influencing the intersegmental communication of the motion segments.

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