脊柱融合术后相邻节段退变的研究进展

随着手术方法的日趋成熟和脊柱内固定器械的日新月异，脊柱融合术的成功率有了明显提高。同时由于脊柱融合术改变了脊柱正常的生物力学环境，各节段所承受应力进行重新分配，融合节段上下相邻椎间盘的应力愈加集中，邻近节段退行性变（adjacent segment degeneration，ASD）的问题则变得更加突出，引起人们越来越多的关注。笔者就近年脊柱融合术后ASD的研究现状及进展做一综述。     

成人脊柱畸形矫形术后力学性并发症的危险因素及防范

成人脊柱畸形（adult spinal deformity,ASD）可引起疼痛、功能受限甚至残疾,严重影响患者生活质量。脊柱矫形手术能够满意地重建脊柱序列,从而改善患者生活质量。然而,围手术期并发症仍然困扰着外科医师,文献报道ASD术后并发症高达74%,其中,约28%的患者需行翻修手术,给患者及家庭造成了严重的经济负担。因此,正确认识这些并发症的危险因素以降低翻修率尤为重要。ASD术后并发症可分为非力学性和力学性。非力学性并发症表现为：神经损伤、感染和硬膜外血肿等。力学性并发症包括：内固定失败、假关节、交界性后凸、冠状面失衡和矫正丢失等。其中,翻修手术主要以力学性并发症为主。     

腰椎后路内固定术后相邻节段退变的研究进展

腰椎后路椎弓根钉内固定融合术现已广泛应用于治疗腰椎退行性疾病、畸形、腰椎滑脱和脊柱肿瘤等,坚强内固定和360°融合亦被视为脊柱稳定手术的金标准。相邻节段退变(adjacent segment degeneration,ASD)是腰椎固定术后相邻节段最常见的病变。随着内固定器械的日趋成熟,术后相邻节段退变引起了越来越多人的关注,研究其发生机制和影响因素,如何有效治疗和预防相邻节段退变的发生逐渐成为研究的热点。本文就腰椎后路内固定术后相邻节段退变的概念、发生率、发生机制、影响因素和治疗作一综述。     

基于脊柱-骨盆矢状面的测量对于腰椎融合术后邻椎病危险因素分析

目的分析脊柱-骨盆矢状面的测量对腰椎融合术后邻椎病(adjacent segment disease,ASD)危险因素。方法回顾性分析2012年10月~2017年10月在本院脊柱中心接受经椎间孔入路椎间植骨融合术(transforaminal lumbar interbody fusion,TLIF)病人资料,随访过程结束后将最终纳入研究病人分成ASD组及非ASD组,多因素Logistic回归分析病人术前脊柱-骨盆矢状面影像学参数与腰椎融合术后ASD发生的相关性。结果纳入210病人最终190例完成随访(90.48%),其中ASD组30例(15.8%),非ASD组160例(84.2%),多因素Logistic回归结果表明,PT值,术中邻近节段的干扰是腰椎融合术后发生ASD的危险因素。结论脊柱-骨盆矢状面平衡对于脊柱的生长发育起着重要的作用,PT值、术中邻近节段的干扰是腰椎融合术后发生ASD的危险因素。     

重视成人脊柱畸形术后的近端交界性后凸

成人脊柱畸形（adult spine deformity,ASD）若出现畸形不断进展、合并冠矢状面失平衡以及保守治疗无效的疼痛,常需手术。与青少年特发性脊柱侧凸畸形不同,成人脊柱侧凸畸形的术后并发症相对较多,如近端交界性后凸（proximal junctional kyphosis,PJK）。有文献报道PJK在成人脊柱畸形术后的发生率高达20%以上,严重的PJK会引起疼痛、功能丧失、畸形进展等一系列问题,甚至最终导致翻修手术。因此掌握PJK的定义、发病率、危险因素及处理方法在治疗ASD中尤为重要。     

成人脊柱畸形远端融合椎的选择问题

<正>成人脊柱畸形(adult spinal deformity,ASD)治疗目标是缓解腰背痛、去除神经压迫、恢复脊柱平衡和改善生活质量。手术方式中融合节段尤其是远端融合椎的选择,由于涉及到术后近、远期疗效问题,引起了学者们的广泛关注。ASD远端融合椎终止于L5、S1还是髂骨,既有共识,亦存有争议,结合文献和自身经验,浅谈一些体会与思考。     

腰椎固定融合术后脊柱-骨盆矢状位序列对相邻节段退变的影响:6年以上随访研究

目的:拟通过至少6年临床资料随访,探讨腰椎融合术后脊柱-骨盆矢状位序列因素对相邻节段退变(ASD)的影响。方法:回顾性分析2002年1月～2006年12月于我院骨科诊断为腰椎管狭窄症而行后路减压固定融合术患者72例,其中男33例,女39例,术时年龄55.9±9.2岁(31～71岁),术后平均随访86.8±7.5个月(72～120个月)。影像学资料包括术前腰椎MRI、正侧屈伸位X线片,末次随访腰椎MRI、全脊柱正侧位X线片;利用院内PACS系统测量骨盆入射角(PI)、骶骨倾斜角(SS)、骨盆倾斜角(PT)、腰椎前凸角(LL)、融合节段LL、剩余LL等。利用MRI与X线片判定术后ASD情况。以106例无症状中老年志愿者全脊柱X线片测量结果作为对照,比较腰椎管狭窄症患者术前及术后远期随访脊柱-骨盆矢状位序列参数,分析术后脊柱-骨盆矢状位序列的变化与ASD的相关性。结果:共50例患者(69.4%,50/72)末次随访时出现ASD;ASD组与无ASD组患者术前及末次随访骨盆矢状位参数(PI、SS、PT)与对照组比较均无显著性差异(P0.05)。术前LL,ASD组患者(32.6°±15.4°)、无ASD组(37.3°±12.0°)显著小于对照组(49.2°±9.1°)(P0.05);末次随访时,无ASD组LL显著大于ASD组(42.8°±10.5°vs 36.3°±14.0°,P0.05),但仍显著小于对照组(P0.05)。42例未融合至S1节段的患者中31例末次随访时出现ASD,30例融合至S1节段的患者中19例出现ASD,尽管两组间ASD发生率并无显著性差异(P=0.341),但对于融合至S1组的患者,出现ASD的患者融合节段更长,LL显著减小,剩余LL显著减小。结论:(1)术后远期LL与ASD的发生存在相关性,充分改善LL可能会降低ASD发生率;(2)尽管融合至S1不是ASD发生率增加的独立危险因素,但对于融合至S1的患者,融合节段越长,术后腰椎前凸曲度越小,剩余的腰椎前凸曲度越平直,会增加ASD发生率。     

腰椎退行性脊柱侧凸术后邻椎病情况及危险因素分析

目的 探讨腰椎退行性脊柱侧凸术后邻椎病(adjacent segment disease, ASD)发生状况及危险因素。方法 回顾性分析2018年1月～2021年1月在本院治疗的退行性脊柱侧凸(degenerative scoliosis, DS)患者135例,均接受短节段减压融合术,术后随访24～60个月,根据是否发ADS分为两组。比较两组人口学资料及手术相关资料。采用Logistic回归分析发生ASD的主要危险因素。结果 135例患者术后3个月、末次随访时的ODI指数、VAS评分均比术前明显改善(P<0.05)。末次随访时,24例发生ASD(ASD组),111例未发生ASD(非ASD组)。ASD组年龄、术前骨盆倾斜角、术前骨盆投射角、术前骨盆投射角/腰椎前凸角匹配度、术前冠状位Cobb角均显著高于非ASD组(P<0.05);Logistic回归分析显示,术前骨盆倾斜角、术前骨盆投射角与腰椎前凸角匹配度、术前冠状位Cobb角,均是影响ASD发生的主要危险因素(P<0.05)。结论 DS患者接受手术治疗可明显改善症状,但遗留ASD风险。ASD的发生与术前骨盆倾斜角、骨...     

严格掌握颈前路融合与非融合手术联合应用的适应证

近年来,基于对邻近节段退变（adjacent segment degeneration,ASD）的再认识,颈前路融合与非融合手术方式选择成为一个新的争论话题。争论的焦点是融合手术对ASD的影响,以及非融合手术是否能达到减少ASD的目的[1]。许多研究报告指出,生物力学改变导致的相邻节段应力增加和椎间盘退变的自然病程均可能导致ASD,不同视角使得ASD的发生机理仍然没有肯定结论。多数学者认为脊柱融合术加速了ASD的发生,ASD也与患者的年龄、手术时相邻节段椎间盘状况、术式选择、融合节段长短、钢板安放位置、植骨块或融合器大小、脊柱生理曲度变化、手术创伤、术后外固定时间长短、辅助治疗、患者自我保护与保健、工作性质与劳动强度、生活方式、坐卧姿势等有直接关系[2]。     

腰椎退变性疾病融合术后邻近节段退变的研究进展

邻近节段退变（adjacent segment degeneration,ASD）是腰椎融合术后邻近节段最常见的病变,其含义较广, 可以泛指融合区邻近节段的所有异常改变。文献报道影像学和症状学邻近节段退变的发生率分别达到了8%～100%和5.2%～18.5%[1]。ASD是在1956年由Anderson在脊柱融合术后邻近节段的退行性滑脱的病例中报道[2],随着内固定器械的日趋成熟,腰椎融合术的成功率明显提高,融合术后所带来的邻近节段退变引起了越来越多人的关注,如何减低或避免邻近节段退变的发生逐渐成为研究热点。     

Adjacent level disk disease--is it really a fusion disease?

Adjacent segment degeneration (ASD) is a relatively common phenomenon after spinal fusion surgery. Whether ASD is a consequence of the previous fusion or an individual's predisposition to continued degeneration remains unsolved to date. This article summarizes the existing biomechanical and clinical literature on the causes and clinical impact of ASD, as well as possible risk factors. Further, the theoretical advantage of motion-preserving technologies that aim to preserve the adjacent segment is discussed.     

Clinical and radiographic evaluation of adult spinal deformities

Adult spinal deformity (ASD) is a heterogeneous group of disorders that affect spinal alignment. We review the clinical evaluation and radiographic assessment of ASD. Evaluation begins with a thorough patient history and a global and spine-specific physical examination. Thorough radiographic evaluation is essential for diagnosis, evaluation of deformity, planning of surgical procedures, and monitoring of outcomes. Spinopelvic parameters can be used to evaluate deformities; they are associated with quality of life, and they help characterize sagittal malalignment and pelvic compensation. Newly described radiographic parameters, including T1 pelvic angle and deformity angular ratio, assist surgeons in the evaluation of ASD.     

Adjacent segment disease in the lumbar spine following different treatment interventions

Background context

Adjacent segment disease (ASD) is symptomatic deterioration of spinal levels adjacent to the site of a previous fusion. A critical issue related to ASD is whether deterioration of spinal segments adjacent to a fusion is due to the spinal intervention or due to the natural history of spinal degenerative disease.

Purpose

The purpose of this review is to summarize the recent clinical literature on adjacent segment disease in light of the natural history, patient-modifiable risk factors, surgical risk factors, sagittal balance, and new technology.

Study design

This review will evaluate the recent literature on genetic and hereditary components of spinal degenerative disease and potential links to the development of ASD.

Methods

After a meticulous search of Medline for relevant articles pertaining to our review, we summarized the recent literature on the rate of ASD and the effect of various interventions, including motion preservation, sagittal imbalance, arthroplasty, and minimally invasive surgery.

Results

The reported rate of ASD after decompression and stabilization procedures is approximately 2% to 3% per year. The factors that are consistently associated with adjacent segment disease include laminectomy adjacent to a fusion and a sagittal imbalance.

Conclusions

Spinal surgical interventions have been associated with ASD. However, whether such interventions may lead to an acceleration of the natural history of the disease remains questionable.     

Pelvic fixation techniques and impact on sagittal balance: A literature review

As adult spinal deformity (ASD) surgery advances, pelvic fixation techniques have evolved to confront several challenges such as pseudoarthrosis and instrumentation failure. Concurrently, ASD literature has identified sagittal balance as one of the pre-eminent factors in clinical outcomes in patients undergoing ASD surgery. However, despite advances in surgical technique and understanding of clinical outcome predictors, there is limited evaluation of the impact of pelvic instrumentation on global sagittal alignment. This review provides context on historical pelvic instrumentation options and assesses the advantages and disadvantages of modern pelvic fixation techniques in ASD surgery with respect to sagittal balance. Available data suggest that pre- and postoperative sagittal balance correction remains an important clinical outcome predictor, but such a correction can be undermined by postoperative complications such as pseudoarthrosis and instrumentation failure over the long term. Therefore, choice of instrumentation construct should not only consider intraoperative factors and immediate sagittal balance correction but also prevention of complications over patients’ full postoperative course. Future research should directly evaluate pelvic fixation techniques in the context of long-term postoperative clinical and radiologic outcomes, specifically sagittal balance.     

A subject-specific method to measure dynamic spinal alignment in adult spinal deformity

BACKGROUND CONTEXTTwo-dimensional static radiography currently forms the golden standard in spinal alignment measurement in adult spinal deformity (ASD). However, these static measurements offer no information on dynamic spinal behavior. To fully understand the functionality and compensation strategies of ASD patients, tools to assess dynamic spinal alignment are needed.PURPOSETherefore, the aim of this study was to introduce, validate and assess the reliability of a new kinematic model to measure dynamic spinal parameters in ASD based on a polynomial function, taking into account the subject-specific anatomy.STUDY DESIGNValidation and reliability studyOUTCOME MEASURESRadiographic parameters, spinal kinematics and range of motion (ROM), Scoliosis Research Society Outcome Questionnaire (SRS-22), Core Outcome Measures Index (COMI).METHODSSpinal alignment of 23 ASD patients and 18 controls was measured using both x-rays and motion capture. Marker positions were corrected to the underlying anatomy and a polynomial function was fitted through these corrected marker positions. By comparing the polynomial method to x-ray measurements concurrent validity was assessed. Test-retest, inter- and intrarater reliability during standing and sit-to-stand (STS) were assessed on a subsample of eight ASD patients and eight controls.RESULTSThe results showed good to excellent correlations (r>0.75) between almost all x-ray and anatomy-corrected polynomial parameters. Anatomy correction consistently led to better correlations than no correction. Intraclass correlation coefficients for the polynomial method were good to excellent (>0.75) between sessions and between and within raters and comparable or even better than radiographic measurements. Also, during STS reliability was excellent. Fair to moderate correlations were found between spinal ROM during STS and quality of life, measured with SRS-22 and COMI.CONCLUSIONSThe results of this study indicate the polynomial method, with subject-specific anatomy correction, can measure spinal alignment in a valid and reliable way using motion capture in both healthy and deformed spines. This method makes it possible to extend evaluation in ASD from mainly static, by means of x-ray measurements, to dynamic and functional assessments.CLINICAL SIGNIFICANCEEventually, this newly obtained dynamic spinal alignment information might lead to new insights in clinical decision-making and new treatment strategies, based and oriented on dynamic parameters and functionality.     

Postoperative complications in adult spinal deformity surgery: An overview of timing,risk factors,and management strategies

Adult spinal deformity (ASD) continues to increase in tandem with a globally aging population. Advances in technology and surgical techniques have significantly improved the efficacy of surgical treatment for ASD. The medical complexity of patients with ASD in combination with the intensive physiologic demands of deformity surgery accentuates the risk of postoperative complications in this patient population. Therefore, this review sequentially outlines postoperative complications in spinal deformity surgery by timing and prevalence, and describes risk factors and management strategies to improve outcomes in patients undergoing surgical treatment for ASD.     

A bibliometric analysis of patient-reported outcome measures in adult spinal deformity,and the future of patient-centric outcome assessments in the era of predictive analytics

Surgical treatment of adult spinal deformity (ASD) is associated with high resource utilization, high costs, and potential complications. In order to generate consensus for treatment paradigms and to demonstrate value, it is crucial to accurately assess clinical outcomes. Historically, objective assessments in ASD were performed by providers, and in recent decades the use of patient-reported outcome measures (PROMs) have become widely incorporated. Here, we report results of a bibliometric analysis of PROMs in ASD, synthesizing a global view of the topic and mapping trends in the field. In the modern era, enabling advancements in predictive modeling and machine learning, along with technology within smartphones and wearables, may supplement traditional patient-centric outcomes assessments and overcome some of their limitations.     

Sublaminar wiring stabilization to prevent adjacent segment degeneration after lumbar spinal fusion

Introduction  Adjacent segment degeneration (ASD) is a complication of lumbar spinal fusion. There are some reports on the cause of this degeneration but none concerning its prevention. We performed sublaminar wiring stabilization to prevent ASD after posterolateral lumbar spinal fusion with instrumentation. The purpose of this study was to prospectively evaluate the efficacy of this procedure. Patients and methods  Between 2003 and 2004, 54 consecutive patients with lumbar spinal canal stenosis and multilevel instability of the lumbar spine underwent posterior decompression and posterolateral fusion with instrumentation. The mean age at the time of surgery was 66.7 ± 1.3 years, and the mean follow-up period was 40.0 ± 1.1 months, with a minimum of 29 months. Twenty-seven of the patients underwent conventional sublaminar wiring stabilization at the cephalad segment adjacent to the site of fusion to prevent ASD (group A), and the other 27 patients did not (group B). Some items were assessed, including clinical outcome using Japanese Orthopaedic Association (JOA) score, sagittal global lumbar alignment, and segmental motion in flexion–extension radiographs of the cephalad vertebral body adjacent to the site of fusion. Results  There were no significant differences in JOA scores between two groups, but 2 patients in group B underwent subsequent surgery due to ASD. Sagittal lumbar alignment did not change in group A but was significantly decreased in group B. With respect to segmental motion in flexion–extension radiographs, group A showed a significant decrease from 6.9° before surgery to 3.4° after surgery, on the other hand group B showed a significant increase from 5.6° before surgery to 8.4° after surgery. Conclusions  In this study, it was suggested that sublaminar wiring stabilization significantly reduces the range of motion of the adjacent segment and preserves sagittal lumbar alignment, which lead to prevention of ASD. The clinical outcome of the subsequent surgeries is relatively poor, so it is important to prevent ASD by any prevention such as sublaminar wiring stabilization.     

New progress in adjacent segment degeneration/disease

Adjacent segment degeneration/disease (ASD) has been generally accepted as a long‐term complication after spinal surgery. Although the incidence of ASD is not very high, it is gradually recognized to be a very important factor in evaluation of the long‐term effect of spinal fusion. There are many views concerning pathogenic factors and ways of prevention and treatment. The authors review and discuss the current research and this article will describe recent advances in ASD.     

Representative dynamic ranges of spinal alignment during gait in patients with mild and severe adult spinal deformities

BACKGROUND CONTEXTSurgical correction strategies for adult spinal deformity (ASD) relies heavily on radiographic alignment goals, however, there is often debate regarding degree of correction and how static alignment translates to physical ability in daily life. Kinematic analysis has the potential to improve the concept of ideal spinal alignment by providing clinically meaningful estimates of dynamic changes in spinal alignment during activities of daily life.PURPOSEEstimate representative dynamic ranges of spinal alignment during gait among ASD patients using 3D motion tracking; compare dynamic alignment between mild and severe deformity patients and to healthy adults.STUDY DESIGN/SETTINGRetrospective review at a single institution.PATIENT SAMPLEFifty-two ASD patients and 46 healthy adults.OUTCOME MEASURESRadiographic alignment, kinematic spine motion, spatiotemporal gait measures, patient reported outcomes (VAS pain, ODI, SRS-22r).METHODSSpinal alignment was assessed radiographically and during standing and overground walking tests. Dynamic alignment was initialized by linking radiographic alignment to kinematic alignment during standing and at initial heel contact during gait. Dynamic changes in maximums and minimums during gait were made relative to initial heel contact for each gait cycle. Total range-of-motion (RoM) was measured for both ASD and healthy subjects. Dynamic alignment measures included coronal and sagittal vertical axes (CVA, SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), and pelvic tilt (PT). ASD patient's deformities were classified as either Mild or Severe based on the SRS-Schwab ASD classification.RESULTSSevere ASD patients had significantly larger dynamic maximum and minimums for SVA, TPA, LL, and PT (all p<.05) compared with Mild ASD patients. ASD patients exhibited little difference in dynamic alignment compared with healthy subjects. Only PT had a significant difference in dynamic RoM compared with healthy (p<.001).CONCLUSIONSMild and Severe ASD patients exhibited similar global dynamic alignment measures during gait and had comparable RoM to healthy subjects except with greater PT and reduced spatiotemporal performance which may be key compensatory mechanisms for dynamic stabilization.