Dural sac cross-sectional area and morphological grade show significant associations with patient-rated outcome of surgery for lumbar central spinal stenosis

Purpose

Lumbar central spinal stenosis (LSS) is one of the most common reasons for spine surgery in the elderly patient. Magnetic resonance imaging (MRI) represents the gold standard for the assessment of LSS and can be used to obtain quantitative measures of the dural sac cross-sectional area (DCSA) or qualitative measures (morphological grades A–D) of the rootlet/cerebrospinal fluid ratio. This study investigated the intercorrelation between these two MRI evaluation methods and explored their respective relationships with the patient baseline clinical status and outcome 12 months after surgery.

Methods

This was a retrospective analysis of prospectively collected data from 157 patients (88 male, 69 female; age 72 ± 7 years) who were undergoing first-time surgery for LSS. Patients with foraminal or isolated lateral stenosis were excluded. The Core Outcome Measures Index (COMI) was completed before and 12 months after surgery. Preoperative T2 axial MRIs were blinded and independently evaluated for DCSA and morphological grade. Spearman rank correlation coefficients described the relationship between the two MRI measures of stenosis severity and between each of these and the COMI baseline and change-scores (pre to 12 months’ postop). Multiple logistic regression analysis (controlling for baseline COMI, age, gender, number of operated levels, health insurance status) was used to analyse the influence of stenosis severity on the achievement of the minimum clinically important change (MCIC) score for COMI and on global treatment outcome (GTO).

Results

There was a correlation of ρ = ?0.69 (p < 0.001) between DCSA and morphological grade. There was no significant correlation between COMI baseline scores and either DCSA or morphological grades (p > 0.85). However, logistic regression revealed significant (p < 0.05) associations between stenosis ratings and 12-month outcome, whereby patients with more severe stenosis (as measured using either of the methods) benefited more from the surgery. Patients with a DCSA <75 mm² or morphological grade D had a 4–13-fold greater odds of achieving the MCIC for COMI or a “good” GTO, compared with patients in the least severe categories of stenosis.

Conclusions

Postoperative outcome was clearly related to the degree of preoperative radiological LSS. The two MRI methods appeared to deliver similar information, as given by the relatively strong correlation between them and their comparable performance in relation to baseline and 12-month outcomes. However, the qualitative morphological grading can be performed in an instant, without measurement tools, and does not deliver less clinically useful information than the more complex and time-consuming measures; as such, it may represent the preferred method in the clinical routine for assessing the extent of radiological stenosis and the likelihood of a positive outcome after decompression.

     

Decision-making in lumbar spinal stenosis: A survey on the influence of the morphology of the dural sac

Surgical decision-making in lumbar spinal stenosis involves assessment of clinical parameters and the severity of the radiological stenosis. We suspected that surgeons based surgical decisions more on dural sac cross-sectional area (DSCA) than on the morphology of the dural sac. We carried out a survey among members of three European spine societies. The axial T2-weighted MR images from ten patients with varying degrees of DSCA and morphological grades according to the recently described morphological classification of lumbar spinal stenosis, with DSCA values disclosed in half the assessed images, were used for evaluation. We provided a clinical scenario to accompany the images, which were shown to 142 responding physicians, mainly orthopaedic surgeons but also some neurosurgeons and others directly involved in treating patients with spinal disorders. As the primary outcome we used the number of respondents who would proceed to surgery for a given DSCA or morphological grade. Substantial agreement among the respondents was observed, with severe or extreme stenosis as defined by the morphological grade leading to surgery. This decision was not dependent on the number of years in practice, medical density or specialty. Disclosing the DSCA did not alter operative decision-making. In all, 40?respondents (29%) had prior knowledge of the morphological grading system, but their responses showed no difference from those who had not. This study suggests that the participants were less influenced by DSCA than by the morphological appearance of the dural sac. Classifying lumbar spinal stenosis according to morphology rather than surface measurements appears to be consistent with current clinical practice.     

Study of dural sac cross-sectional area in early and late phases after lumbar decompression surgery

Background contextLumbar magnetic resonance imaging (MRI) in the early phase after lumbar decompression surgery sometimes reveals an absence in the expansion of the dural sac, regardless of the presence or absence of clinical symptoms; the reason for such a condition is often difficult to explain. There are some reports that compared the dural sac area between the preoperative and early postoperative phases; however, no report exists that compares the early and late phases after lumbar decompression surgery.PurposeThe purpose of this study was to compare changes in the dural sac cross-sectional area (CSA) in the early and late phases after lumbar decompression surgery. Factors related to the insufficient increase in the postoperative dural sac CSA were also analyzed.Study designThe dural sac CSA preoperatively and in the early and late phases after lumbar decompression surgery was analyzed retrospectively.Patient sampleOf 105 patients who underwent lumbar decompression surgery and MRI within 1 week and again more than 1 month after surgery, 83 patients (38 men, 45 women; mean age 65.6 years) were included in this study.Outcome measuresCross-sectional areas of the dural sac.MethodsThe dural sac CSA was measured within 1 week (early phase) and more than 1 month (late phase) after surgery, using T2 axial plane MR images. The preoperative and the early and late postoperative CSAs were measured at the same site. The relationship between the dural sac area and age and presence of dural injury was also analyzed.ResultsThe mean area of the dural sac preoperatively and in the early and late postoperative phases was 71.2±4.9, 102.2±5.7, and 164.1±6.9 mm², respectively. The mean area increased significantly (p<.001) between the preoperative and postoperative early phases and between the early and late postoperative phases. The dural sac area in the early (p=.16) and late (p=.086) phases did not differ significantly between patients aged 75 years or more and those aged less than 75 years. In the case of lumbar spinal stenosis, patients with a preoperative dural sac area of less than 60 mm² showed a significantly (p<.001) smaller dural sac area in the early and late postoperative phases, compared with patients with a preoperative dural sac area of 60 mm² or more. No significant increase was observed in the dural sac area with regard to the presence or absence of dural injury.ConclusionsThe dural sac area increased significantly between the early and late postoperative phases. No significant difference in the dural sac CSA between the early and late postoperative phases was observed with regard to age or the presence/absence of dural sac injury. A smaller preoperative dural sac CSA resulted in a smaller dural sac CSA in the early and late postoperative phases.     

Dynamic changes in the dural sac of patients with lumbar canal stenosis evaluated by multidetector-row computed tomography after myelography

Purpose

Some reported studies have evaluated the dural sac in patients with lumbar spinal stenosis (LSS) by computed tomography (CT) after conventional myelography or magnetic resonance imaging (MRI). But they have been only able to evaluate static factors. No reports have described detailed dynamic changes in the dural sac during flexion and extension observed by multidetector-row computed tomography (MDCT). The aim of this study was to elucidate or demonstrate, in detail, the influence of dynamic factors on the severity of stenosis.

Methods

One hundred patients with LSS were enrolled in this study. All underwent MDCT in both flexion and extension positions after myelography, in addition to undergoing MRI. The anteroposterior diameter (AP-distance) and cross-sectional area of the dural sac (D-area) were measured at each disc level between L1–2 and L5–S1. The dynamic change in the D-area was defined as the absolute value of the difference between flexion and extension. The rate of dynamic change (dynamic change in D-area/D-area at flexion) in the dural sac at each disc level was also calculated.

Results

The average AP-distance in flexion/extension (mm) was 9.2/7.4 at L3–4 and 8.3/7.4 at L4–5. The average D-area in flexion/extension (mm²) was 96.3/73.6 at L3–4 and 72.3/61.0 at L4–5. The values were significantly lower in extension than in flexion at all disc levels from L1–2 to L5–S1. AP-distance was narrowest and D-area smallest at L4–5 during extension. The rates of dynamic changes at L2–3 and L3–4 were higher than those at L4–5.

Conclusions

MDCT clearly elucidated the dynamic changes in the lumbar dural sac. Before surgery, MDCT after myelography should be used to evaluate the dynamic change during flexion and extension, especially at L2–3, L3–4, and L4–5.     

Coflex系统治疗退行性腰椎管狭窄症

 目的 探讨Coflex系统治疗退行性腰椎管狭窄症的初步临床疗效。
方法 2008年3月至2009年8,采用腰椎后路椎管减压棘突间植入Coflex系统治疗退行性腰椎管狭窄症患者26例,男11例,女15例;年龄45～78岁,平均65.4岁。L_3,4节段7例,L_4,5节段13例,L_3,4合并L_4,5节段6例。术前MRI和CT扫描证实L_3,4和（或）L_4,5节段黄韧带增厚,关节突关节骨质增生,合并椎间盘突出致中央椎管及侧隐窝狭窄,神经根或马尾受压。应用eFilm及CAD软件测量术前及术后3个月、12个月手术节段椎间隙前缘高度、后缘高度、活动度,术前、术后椎管面积;采用日本骨科学会评分标准（Japanese Orthopaedic Association,JOA）进行功能评估。
结果 全部病例随访12～24个月,平均15个月。术后患者腰腿疼痛症状均明显缓解,日常生活能力改善。JOA评分由术前平均（15.46±4.30）分改善至术后3个月（24.50±1.58）分,责任节段椎管面积由术前平均（218.4±16.2）mm 2增加至术后（264.6±9.9）mm 2。单节段椎间隙前缘高度无明显变化,椎间隙后缘高度较术前增加,随时间延长高度有所下降。术后手术节段仍保留一定的活动度,但较术前明显下降。Coflex系统无松动、断裂及脱出。
结论 Coflex系统治疗退行性腰椎管狭窄症可较好地维持相应节段的稳定性,安全可行,近期疗效满意。     

老年退行性腰椎管狭窄症患者全椎板切除术后远期X线变化

目的：观察老年退行性腰椎管狭窄症患者全椎板切除减压术后远期腰椎X线影像变化情况。方法：1991年1月～2001年12月,我院行单纯全椎板切除术治疗老年退行性腰椎管狭窄症患者132例,其中X线资料完整者63例,男32例,女31例,年龄65～83岁,平均72.3岁。分析术前和术后X线资料,观察末次随访时手术节段及其相邻上、下节段的椎体间相对距离、相对位移、椎体间活动角度及椎体间冠状面活动度和水平面旋转度的改变。结果：术后随访5～15年,平均7.3年,125个全椎板切除减压节段末次随访时与术前比较,椎体间相对距离明显降低（P=0.001）,椎体间相对位移略有增大（P=0.1）,椎体间活动角度明显增大（P=0.01）,椎体间冠状面活动角度略有增大（P=0.1）,椎体间水平面相对旋转度明显增大（P=0.01）。112个减压相邻上、下节段手术前后比较,上述指标变化均不明显（P〉0.05）。结论：退行性腰椎管狭窄症患者行全椎板切除减压术后减压节段X线影像退变迹象明显,减压相邻上、下节段退变迹象较轻。     

老年腰椎椎管狭窄症患者术中硬膜囊撕裂位置及术中术后处理对策

目的探讨老年腰椎椎管狭窄症患者手术发生硬膜囊撕裂的解剖学机制,比较撕裂位置及术中、术后处理对策。方法回顾性分析2012年01月~2014年01月本院行腰椎后路手术的216例〉70岁老年患者,记录患者一般资料、病程时间、术前诊断、手术方式和节段、术中硬膜囊撕裂的位置、术后脑脊液漏情况和处理方法以及并发症等。结果共计151例患者入选,其中男89例,女62例,年龄70~93岁,平均78.12岁。术中发生硬膜囊撕裂共计34例,术后出现脑脊液漏23例,硬膜囊撕裂位置发生率硬膜囊后外侧〉根袖〉硬膜囊外侧〉硬膜囊腹侧。术中采取硬膜囊缝合修补、明胶海绵压迫、生物蛋白胶粘合等处理,术后常规给予预防感染、神经根脱水、补液等治疗,均于术后3~10 d拔管,3~4周切口愈合,全部患者未出现严重并发症。结论 〉70岁老年腰椎椎管狭窄症患者术中硬膜囊撕裂及术后脑脊液漏的发生率高于整体人群,且多位于硬膜囊后外侧及根袖,术中及时发现并仔细缝合或修补破损的硬膜、术后间断夹闭引流管、延长拔管时间能获得良好的效果。     

神经根沉降征与重度中央型/混合型腰椎管狭窄受压节段硬膜囊横截面积变化的相关性研究

目的:评价神经根沉降征与重度中央型/混合型腰椎管狭窄节段硬膜囊横截面积变化之间的关系,并探讨其可能的发生机制。方法:回顾性分析2012年1月~2015年6月齐齐哈尔医学院附属第二医院明确诊断为腰椎管狭窄症(LSS)的87例患者的MRI图像,均被确诊为中央型或混合型LSS,MRI明确显示L3/4或L4/5节段至少一个扫描层面的硬膜囊横截面积(cross-sectional area,CSA)≤80mm~2。患者均有间歇性跛行,行走距离≤500m。单节段狭窄61例,其中L3/4狭窄19例,L4/5狭窄42例;双节段(L3/4、L4/5)狭窄26例,共筛选出符合标准的狭窄节段113个,分析其中神经根沉降征阳性的发生率,并将其分为沉降征阳性组与沉降征阴性组。L3/4、L4/5节段各扫描3层,在横截面MRI T2加权相图像上测量最小硬膜囊CSA、最小椎管正中矢状径(PAD)、最大硬膜囊横截面积差(CSAD),组间比较采用t检验;进一步采用受试者工作特征曲线(receiver operating characteristic curve,ROC-curve)即ROC曲线分析神经根沉降征阳性发生率与最小硬膜囊CSA、最小椎管PAD、最大硬膜囊CSAD之间的相关性。结果:在113个重度腰椎管狭窄节段中,28个狭窄节段沉降征阴性,85个狭窄节段沉降征阳性,神经根沉降征阳性发生率为75.22%。神经根沉降征阳性组最小椎管PAD为12.00±2.10mm,阴性组为11.47±2.04mm,两组比较有统计学差异(P0.05);阳性组最大硬膜囊CSAD为36.94±13.97mm~2,阴性组为18.60±7.70mm~2,两组比较有统计学差异(P0.01);阳性组最小硬膜囊CSA为47.34±12.55mm~2,阴性组为45.16±15.35mm~2,两组比较无统计学差异(P0.05)。最小椎管PAD的ROC曲线下面积值(AUC)为0.64(P0.05);最大硬膜囊CSAD的ROC曲线下面积值(AUC)为0.929(P0.01);最小硬膜囊CSA的ROC曲线下面积值(AUC)为0.557(P0.05)。结论:阳性神经根沉降征的发生与狭窄节段硬膜囊受压变窄的变化程度有关,硬膜囊最大CSAD可作为评估腰椎管狭窄节段硬膜囊受压变窄的变化程度的指标。     

Predictors of treatment choice in lumbar spinal stenosis: a spine patient outcomes research trial study

STUDY DESIGN.: A retrospective cohort study. OBJECTIVE.: In this article, we examined the Spine Patient Outcomes Research Trial lumbar stenosis observational cohort to determine baseline patient characteristics that are predictive of the treatment patients chose. We also evaluated cutoff points on validated patient questionnaires that differentiate patients who chose surgery from those who chose nonsurgical management. SUMMARY OF BACKGROUND DATA.: Although the evidence from current studies suggests that surgical intervention is effective for lumbar spinal stenosis, the same studies show that nonoperative patients also improve. Thus, the reasons for patients choosing surgery versus nonoperative care are of continuing interest. METHODS.: Baseline patient and clinical characteristics between those who received operative intervention and those who received nonoperative care were compared to determine baseline predictors of lumbar spinal stenosis management. Also, an evaluation of responses to the 36-Item Short Form Health Survey Bodily Pain (BP), 36-Item Short Form Health Survey Physical Function (PF), and the modified Oswestry Disability Index (ODI) questionnaires was performed to determine the percentage of patients choosing surgical versus nonoperative care relative to their initial questionnaire values. RESULTS.: This analysis looked at the 356 patients in the observational spinal stenosis cohort of Spine Patient Outcomes Research Trial who completed at least 1 follow-up visit. Patients choosing surgery were younger (P = 0.022), had worse BP (P < 0.001), worse PF (P < 0.001), worse ODI (P < 0.001), worse Stenosis Bothersomeness Index (P < 0.001), were dissatisfied with their symptoms (P = 0.001), and had a worse self-assessed health trend (P < 0.001). Patients tended to choose surgery if they had lateral recess stenosis (P = 0.022). Kaplan-Meier curves demonstrate that patients with a BP score of 32 or less, PF score of 30 or less, and ODI greater than 29 chose surgery 75% of the time. CONCLUSION.: A greater understanding of baseline characteristics that influence patient choices in the treatment of lumbar spinal stenosis can aid the patient and the surgeon during the shared decision-making process.     

Operative treatment for lumbar disc protrusion with fragment of nucleus pulposus in the dural sac]

Four cases of lumbar disc protrusion with fragments of nucleus pulposus in the dural sac are reported, representing 0.3% of 1555 cases surgically treated over the past 35 years. All four cases were severely affected with distinct clinical manifestations of prolapsed disc, acute onset or sudden deterioration, pain, numbness, weakness, partial or complete paraplegia, and disturbances of urination and defecation accompanied by symptoms of severe and extensive spinal stenosis. They were treated with total laminectomy, section of dural sac, separation of adhesion and removal of fragments of nucleus pulposus. The results were excellent in one, Good in two and fair in one patient as revealed by the follow-up study which ranged from 4 months to 6 years. The clinical features, pathology, cause of prolapse, diagnosis, some points for attention concerning its management as well as that of adhesive arachnoiditis are discussed.     

Adjacent segment hypermobility after lumbar spine fusion: no association with progressive degeneration of the segment 5 years after surgery

Background and purpose Increased intradiscal pressure and relative segmental hypermobility are in vitro observations supporting the idea of increased postoperative load being a reason for progressive degeneration of the free mobile segment adjacent to a lumbar fusion. These mechanisms have been difficult to confirm in clinical studies, and an alternative theory claims instead that the adjacent segment degeneration follows a natural degenerative course in patients who are predisposed. We examined 9 patients 5 years after lumbar fusion, to assess whether relative hypermobility of the segment adjacent to fusion could be correlated to progressive degeneration of the same segment.

Patients and methods The 9 patients, all of whom had been treated with a lumbar fusion after a preoperative intervertebral mobility assessment by spinal RSA, were re-examined 5 years after surgery. The intervertebral translations of the vertebra proximal to the fusion were determined by RSA and compared to the mobility of the same lumbar segment before fusion. The disc height and any progressive reduction at the two levels proximal to the one fused were measured on conventional radiographs.

Results Adjacent segment mobility 5 years after fusion—expressed as mean transverse, vertical, and sagittal translation of the vertebra proximal to fusion— was not significantly changed compared to the mobility measured before surgery. Increased mobility of the segment seen in 5 individual patients was not associated with progressive degeneration of the same segment or to a poor clinical outcome.

Interpretation Hypermobility of the segment adjacent to fusion is not a general finding. Increased mobility that can be seen in certain individuals does not impair the 5-year result. The significance of mechanical alterations in adjacent segment degeneration is uncertain, and it is possibly overestimated.     

Therapeutic exercise in the treatment of patients with lumbar spinal stenosis

Lumbar spinal stenosis is a condition that may cause significant pain and associated disability, especially in older patients. It is being recognized with increasing frequency as the population continues to age, and is the most common diagnosis associated with lumbar spine surgery in patients older than 65 years of age. The natural history of lumbar spinal stenosis is not necessarily one of progressive deterioration. Conservative treatment is advocated in patients with mild to moderate symptoms of lumbar spinal stenosis, and may include therapeutic exercise. The therapeutic exercise program must be prescribed with a thorough understanding of the contributing pathoanatomic and pathophysiologic factors, and should be tailored to each patient based on his or her history and physical examination. Components of the program are described in detail and include specific stretching and strengthening exercises, general conditioning exercises, and education in proper posture and body mechanics. Randomized controlled studies are needed to help clarify the indications for conservative versus surgical treatment, to determine which components of the therapeutic exercise program are the most beneficial, and to compare outcomes after conservative or surgical measures.     

加压植骨联合单枚Cage的椎体间融合与后外侧融合治疗双节段腰椎椎管狭窄症临床效果的回顾性研究

目的探讨双节段腰椎椎管狭窄症后路减压手术后行椎间加压植骨联合单枚Cage置入的椎体间融合术（posterior lumbar interbody fusion,PLIF）与后外侧融合术（posterolateral fusion,PLF）的临床效果。方法回顾性随访分析53例双节段腰椎椎管狭窄症行后路椎管减压、融合手术的患者,分为2组,PLF组31例,PLIF组22例。对2组患者手术情况进行比较,手术前、后及末次随访进行日本骨科协会（Japanese Orthopaedic Association,JOA）评分及下腰痛的视觉模拟量表（visual analog scale,VAS）评分。结果 2组手术时间差异有统计学意义（P〈0.05）;出血量、输血量差异无统计学意义（P〉0.05）;JOA评分,手术前2组差异无统计学意义（P〉0.05）,术后2组差异有统计学意义（P〈0.05）;术后2组下腰背疼痛的VAS评分差异有统计学意义（P〈0.01）。结论椎弓根螺钉内固定椎间加压植骨联合单枚Cage置入椎体间融合术较后外侧融合效果肯定,手术方式安全,手术后恢复快,出现下腰疼痛病例少,融合率高。     

单纯椎板减压治疗退变性椎管狭窄症并腰椎侧凸的疗效及其影响因素

目的：探讨单纯椎板减压治疗退变性椎管狭窄症并腰椎侧凸的效果及其影响因素。方法：1996年-2000年我科收治的资料完整的退变性椎管狭窄症合并腰椎侧凸患者57例，均采用单纯腰椎椎板减压术治疗。使用JOA评分标准进行疗效评价，根据JOA评分恢复率（recoverrate，RR）将患者分为效果满意组（RR≥50％）和效果不满意组（RR〈50％），对腰椎前凸角、侧凸角、腰椎活动度以及L4椎体倾斜率和侧向位移等影像学参数与l临床治疗效果的关系进行统计分析。结果：本组随访3～7年，平均5．1年，效果满意者42例，不满意者15例，统计分析显示腰椎前凸、活动度、L4椎体的倾斜率和手术减压节段对手术效果有显著影响（P〈0．05），与效果不满意组相比，疗效满意组患者术前腰椎前凸小，活动度低，L4椎体倾斜率不明显，需要手术减压的节段少。结论：对腰椎前凸较小、活动度低和L4椎体倾斜率较小的椎管狭窄症合并腰椎侧凸的患者使用短节段全椎板减压可以获得满意的疗效。