Rigid fixation of the lumbar spine alters the motion and mechanical stability at the adjacent segment level (original) (raw)
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Adjacent segment degeneration and adjacent segment disease: the consequences of spinal fusion?
The Spine Journal, 2004
Given the number of spinal fusions performed annually, concerns have mounted over the potential for adjacent segment degeneration (radiographic changes of degeneration at levels adjacent to a spinal fusion) and adjacent segment disease (development of new symptoms correlating with adjacent segment degeneration). This article reviews documented evidence on adjacent segment degeneration and disease as it relates to cervical and lumbar arthrodesis. There appears to be an incidence of adjacent segment degeneration and disease after arthrodesis that may be related to natural degeneration or the adjacent fusion. It remains to be seen whether restoration of motion with disc arthroplasty will alter the rate of adjacent segment degeneration or disease. Ć 2004 Elsevier Inc. All rights reserved.
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2016
Treatment of degenerative spinal disorders by fusion produces abnormal mechanical conditions at mobile segments above or below the site of spinal disorders and is clinically referred to as adjacent segments disc disease (ASDD) or transition syndrome in the case of a previous surgical treatment. The aim of the current study is to understand with the help of poro-elastic finite element models how single or two level degeneration of lower lumbar levels influences motions at adjacent levels and compare the findings to motions produced by single or two level fusions when the adjacent disk has varying degree of degeneration. Validated grade specific finite element models including varying grades of disc degeneration at lower lumbar levels with and without fusion were developed and used to determine motions at all levels of the lumbar spine due to applied moment loads. Results showed that adjacent disc motions do depend on severity of disc degeneration, number of disc degenerated or fused ...
Etiology-Based Classification of Adjacent Segment Disease Following Lumbar Spine Fusion
HSS Journal ®, 2019
Background: Adjacent segment disease (ASDz) is a potential complication following lumbar spinal fusion. A common nomenclature based on etiology and ASDz type does not exist and is needed to assist with clinical prognostication, decision making, and management. Questions/ Purposes: The objective of this study was to develop an etiology-based classification system for ASDz following lumbar fusion. Methods: We conducted a retrospective chart review of 65 consecutive patients who had undergone both a lumbar fusion performed by a single surgeon and a subsequent procedure for ASDz. We established an etiology-based classification system for lumbar ASDz with the following six categories: "degenerative" (degenerative disc disease or spondylosis), "neurologic" (disc herniation, stenosis), "instability" (spondylolisthesis, rotatory subluxation), "deformity" (scoliosis, kyphosis), "complex" (fracture, infection), or "combined." Based on this scheme, we determined the rate of ASDz in each etiologic category. Results: Of the 65 patients, 27 (41.5%) underwent surgery for neurogenic claudication or radiculopathy for adjacentlevel stenosis or disc herniation and were classified as "neurologic." Ten patients (15.4%) had progressive degenerative disc pathology at the adjacent level and were classified as "degenerative." Ten patients (15.4%) had spondylolisthesis or instability and were classified as "instability," and three patients (4.6%) required revision surgery for adjacent-level kyphosis or scoliosis and were classified as "deformity." Fifteen patients (23.1%) had multiple diagnoses that included a combination of categories and were classified as "combined." Conclusion: This is the first study to propose an etiology-based classification scheme of ASDz following lumbar spine fusion. This simple classification system may allow for the grouping and standardization of patients with similar pathologies and thus for more specific pre-operative diagnoses, personalized treatments, and improved outcome analyses.
Adjacent Segment Disease After Lumbar Spinal Fusion: A Systematic Review of the Current Literature
Seminars in Spine Surgery, 2011
The objectives are to comprehensively define adjacent segment disease; highlight advances in the approach to spinal disorders, present the identified risk factors; examine outcomes; and summarize current recommendations. The literature supports previous degeneration and altered biomechanics of the spine as causes of adjacent segment disease. Excessive facet degeneration is a risk factor. Clinical outcome scores show improvement irrespective of procedure type. The number of spinal segments fused, fusion level, and age yield conflicting reports regarding their contribution to adjacent segment disease. Arthroplasty, dynamic stabilization, and interspinous process implants are effective in decreasing incidence.
Early Adjacent Segment Degeneration after Short Lumbar Fusion
Study design: Retrospective cohort study. Object: To assess the factors that may be important in the early adjacent segment disease (ASD) development after one level lumbar fusion. Summary: Today in a review of the world literature there is no consensus about the main risk factors importance for this disease, as well as the terms and conditions of its occurrence. And today there are more and more questions about the reasons for the early development of ASD in the event of a short fixation. Methods: This study evaluated 146 patients who underwent one level 360° fusion lumbar surgery for degenerative lumbar disease between 2005 and 2012. We compare 2 groups according to the presence and extent of initial degenerative changes in the adjacent upper segment. These groups were comparable in terms of main risk factors for ASD such as obesity, age, smoking, menopause, global balance disturbance. Patients in both groups had no significant differences in sex and age composition, the level of quality of life and daily physical activity. First group include 86 patients with no preexisting or 1 to 3 stage degenerative changes by Pfirrmann modified, second group include 60 patients with initial adjacent disk degenerative changes of stage 4 and above according Pfirrmann modified classification. The average follow-up period was 42.2 months (range, 28–112 months). Results: In the I group symptomatic ASD was found in 14 (16,3%) cases and ASD average development time was 35 (8-56) months. In the II group during the follow-up period 24 (40%) patients had ASD with average development time 21,5 (3-46) months. Symptomatic adjacent segment pathology was significantly more frequent in the II group (p < 0.05). The analysis of the symptomatic ASD timing has been obtained statistically significant data on the earlier development of this disease in the second group (p < 0.05). Conclusion: Patients with pre-existing degenerative changes in adjacent levels above stage 3 by Pfirrmann must be assigned to a high risk group for early ASD development even in the short lumbar fusion.
Factors Predictive of Adjacent Segment Disease After Lumbar Spinal Fusion
World Neurosurgery, 2020
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Risk Factors for Adjacent Segment Disease Development after Lumbar Fusion
Purpose To identify factors which may be important in the occurrence of symptomatic adjacent segment disease (ASD) after lumbar fusion. Overview of Literature Many reports have been published about the risk factors for ASD after lumbar fusion. Despite on the great numbers of risk factors identified for ASD development, study results have been inconsistent and there is controversy regarding which are the most important. Methods This study evaluated 120 patients who underwent 360° fusion lumbar surgery from 2007 to 2012. We separated the population into two groups: the first group included 60 patients with long lumbar fusion (three or more levels) and the second group included 60 patients with short lumbar fusion (less than three levels). Results In the first group, symptomatic ASD was found in 19 cases during the one year follow-up. There were 14 cases with sagit- tal imbalance and 5 cases at the incipient stage of disc degeneration according to the preoperative magnetic resonance imaging. At the three year follow-up, symptomatic ASD was diagnosed in 31 cases, of which 17 patients had postoperative sagittal balance disturbance. In the second group, 10 patients had ASD at the one year follow-up. Among these cases, preoperative disc degenerative changes were identified in 8 patients. Sagittal imbalance was found only in 2 cases with symptomatic ASD at the one year follow- up. At the three year follow-up, the number of patients with symptomatic ASD increased to 14. Among them, 13 patients had initial preoperative adjacent disc degenerative changes. Conclusions Patients with postoperative sagittal imbalance have a statistically significant increased risk of developing symptomatic ASD due to an overloading the adjacent segments and limited compensatory capacities due to the large number of fixed mobile segments. In the case of a short fixation, preoperative degenerative changes are more important factors in the development of ASD.
Adjacent segment degeneration following lumbar spine fusion and lumbar discectomy remains a widely known problem, but due to insufficient knowledge regarding the factors that contribute to its occurrence it is difficult to diagnose considering the fact that it has variable presentation in terms of the symptoms it produces, the time frame for its occurance and radiological changes. Our study shows that both in single level discectomy and post instrumented fusion and is marginally more in post single level discectomy without fusion. In both groups cephalic segment is more affected as compared to the caudad segment. There is a significant relationship between radiological degeneration and the clinical adjacent segment degeneration. It has been seen that there is a significant relation between degeneration and chronic smokers both radiologically and clinically. Since there is only marginally difference, we hold on to our hypothesis that the role of natural degeneration is more compared to the role of instrumented fusion causing adjacent segment degeneration. Thus we have to rule out natural and post surgical causes of adjacent segment degeneration leading to different clinical complaints of the patient and manage it accordingly. Introduction Adjacent segment degeneration (ASD) following lumbar spine fusion and lumbar discectomy remains a widely known problem, but due to insufficient knowledge regarding the factors that contribute to its occurrence it is difficult to diagnose considering the fact that it has variable presentation in terms of the symptoms it produces, the time frame for its occurance and radiological changes [1]. Another of the challenges is to distinguish it from the more common age-related degenerative process. Our understanding of biomechanics of spine is increasing hence the indication of adjacent segment degeneration in increasing by the day. Also, indication for spinal surgery are increasing hence there is increase incidence of degeneration. A concern regarding posterior lumbar spine fusion is the potential for adjacent segment degeneration cephalad or caudad to the fusion segment. The degeneration has to be seen in a segment above and below. Many new instrumentation and technique are being marketed with a goal to halt progress of asd or prevent it. So, it would be worth for every spine surgeon to be familiar with the topic and new instrumentation. This study is an attempt to explore the possibility of adjacent segment degeneration after index Surgery, its time pattern and its clinical behavior. This study also explore current views on newer fusion technique and its impact on outcome of ASD. Adjacent segment degeneration in the lumbar and lumbosacral spine has been studied and Radiographic signs of degeneration of disc spaces adjacent to the site of a lumbar fusion discectomy may lead to clinical symptoms of radiculopathy, discogenic pain, or stenosis referable to that level.
Pakistan Journal Of Neurological Surgery, 2020
Objective: To determine the chances of adjacent segment disease (ASD) and risk factors after posterior lumbar interbody fusion (PLIF). Material and Methods: 110 patients of both genders with degenerative lumbar instability at L4/5 level were included in my study. We did PLIF in all our patients and followed our patients for one year. The following parameters were measured: the degree of lumbar lordosis, the degree lumbosacral angle, the disc space height and their dynamic angulation and the displacement of L3 over L4. We checked the outcome with the help of the Japanese orthopedic association (JOA) and Oswestry disability index (ODI). We divided the patients into groups A and B; group A includes patients with progression of degeneration at the proximal level (L3-L4), while group B with no progression of disease at proximal level. Results: The 86 patients (78.18%) were in group A, and 24 patients (21.88%) were in group B. There were no significant difference in radiological paramet...
Cureus, 2019
Study design Biomechanical cadaveric study Objective To compare biomechanical properties of a single stand-alone interbody fusion and a single-level pedicle screw construct above a previous lumbar pedicle fusion. Summary of background data Adjacent segment disease (ASD) is spondylosis of adjacent vertebral segments after previous spinal fusion. Despite the consensus that ASD is clinically significant, the surgical treatment of ASD is controversial. Methods Lateral lumbar interbody fusion (LLIF) and posterior spinal fusion (PSF) with pedicle screws were analyzed within a validated cadaveric lumbar fusion model. L3-4 vertebral segment motion was analyzed within the following simulations: without implants (intact), L3-4 LLIF-only, L3-4 LLIF with previous L4-S1 PSF, L3-4 PSF with previous L4-S1 PSF, and L4-S1 PSF alone. L3-4 motion values were measured during flexion/extension with and without axial load, side bending, and axial rotation. Results L3-4 motion in the intact model was found to be 4.7 ± 1.2 degrees. L3-4 LLIF-only decreased motion to 1.9 ± 1.1 degrees. L3-4 LLIF with previous L4-S1 fusion demonstrated less motion in all planes with and without loading (p < 0.05) compared to an intact spine. However, L3-4 motion with flexion/extension and lateral bending was noted to be greater compared to the L3-S1 construct (p < 0.5). The L3-S1 PSF construct decreased motion to less than 1° in all planes of motion with or without loading (p < 0.05). The L3-4 PSF with previous L4-S1 PSF constructs decreased the flexion/extension motion by 92.4% compared to the intact spine, whereas the L3-4 LLIF with previous L4-S1 PSF constructs decreased motion by 61.2%. Conclusions Stand-alone LLIF above a previous posterolateral fusion significantly decreases motion at the adjacent segment, demonstrating its utility in treating ASD without necessitating revision. The stand-alone LLIF is a biomechanically sound option in the treatment of ASD and is advantageous in patient populations who may benefit from less invasive surgical options.