The analysis of segmental mobility with different lumbar radiographs in symptomatic patients with a spondylolisthesis

Mapping the field of spondylolisthesis: A bibliometric analysis

BACKGROUND

In recent years, the number of studies on spondylolisthesis has been increasing, and there are many publications on this disorder. To our knowledge, there is no bibliometric analysis of spondylolisthesis to date.

AIM

To investigate emerging directions in Spondylolisthesis research and systematically evaluate the academic literature with the highest citation impact within this field.

METHODS

All data were collected from the Web of Science Core Collection database. Years of publications, countries, journals, institutions and total number of citations were extracted and analyzed by VOSviewer software. In addition, we analyzed the top 100 most-cited articles on spondylolisthesis.

RESULTS

A total of 1831 articles related to spondylolisthesis were identified. The frequency of publications on spondylolisthesis has increased dramatically over time. Among all countries, United States has contributed the most publications on spondylolisthesis (n = 574). The institution with the most articles was the University of California, San Francisco (n = 52). Spine topped the list of journals and has published 291 spondylolisthesis-related reports. The hotspot of research changed from posterolateral fusion to interbody fusion.

CONCLUSION

In recent years, academic investigations on spondylolisthesis have exhibited significant growth. As the inaugural bibliometric evaluation in this domain, our research establishes a methodological framework for synthesizing the historical progression and current advancements of spondylolisthesis studies.

Is There a Need for Functional Radiographs in Diagnosing Lumbar Instability?

STUDY DESIGN

Retrospective radiological database analysis.

OBJECTIVE

The aim of this study was to assess the value of functional radiography (FRF = flexion; FRE = extension) compared to MRI and standing sagittal plane full spine radiography (SP) with low-grade spondylolisthesis.

METHODS

Sagittal translation (ST) and rotation (SR) were measured between all lumbar levels to assess instability. The differences for ST and SR of SP and FRE as well as MRI and FRF were calculated. In addition, the lumbar lordosis, the sacral slope, the pelvic tilt and the pelvic incidence were measured.

RESULTS

Radiological datasets of 55 patients with 165 lumbar segments fulfilled inclusion criteria. Instability was diagnosed in 20 segments (12.1%) with SP/MRI compared to 14 segments (8.5%) using FRF/FRE with ST. SR functional radiographs showed instability in 41 segments (25%) and 23 segments (14%) using SP/MRI. The intraclass correlation coefficients (ICC) of ST between SP and FRE for L3/L4, L4/L5, and L5/S1 were 0.74, 0.84 and 0.97, respectively, indicating moderate to excellent agreement between imaging methods. For SP/FRE, the ICCs of the SR were 0.72, 0.61 and 0.64, respectively with moderate agreement. The ICCs of the ST for L3/4, L4/5, and L5/S1 showed moderate to good agreement between MRI and FRF with values of 0.52, 0.77, and 0.80, respectively. Regarding SR, poor agreement between MRI and FRF was observed. The ICCs for L3/4, L4/5, L5/S1 were 0.16, 0.23 and 0.23.

CONCLUSION

Based on our results, instability may also be diagnosed by calculating the difference in the ST in SP and MRI without additional functional radiographs. However, FRF showed translational instability more clearly than MRI in some patients and might still be an asset in borderline cases.

High intensity in interspinous ligaments: a diagnostic sign of lumbar instability and back pain for degenerative lumbar spondylolisthesis

BACKGROUND

To investigate the clinical significance of high intensity signals in interspinous ligaments at the affected segment in degenerative lumbar spondylolisthesis (DLS), as well as to determine the most effective diagnostic modalities for evaluating segmental instability.

METHODS

This study reviewed a consecutive series of patients with L4/5 DLS between July 2023 and December 2023. The enrolled patients were divided into two groups based on the presence or absence of high-intensity signals in interspinous ligaments: the higher group (Group H), and the non-higher group (Group NH). Translational and angular motion was determined using flexion and extension (FE) radiographs or a sitting lumbar lateral radiograph with a supine sagittal MR image (combined, S-MR). The five-repetition sit-to-stand test (5R-STS) was employed to evaluate patients' objective functional impairment (OFI).

RESULTS

Overall, 73 patients were enrolled in this study, and there were 22 (30.1%) patients in group H and 51(69.9%) patients in group NH, with an average age of 60.3 ± 8.1 years. The patients in Group H exhibited significantly longer 5R-STS times and serious OFI compared to those in Group NH. Compared to Group NH, Group H exhibited significantly higher SP in the sitting position (21.8% vs 16.7%; P < 0.001*), while no significant differences were observed in the upright, flexion, extension, and supine MRI positions (all P values > 0.05). In Group H, "instability" was recognized in 77.3% of patients using S-MR versus 40.9% patients using FE (P < 0.001); While in Group NH, no significant difference was observed in the incidence of "instability" between FE and s-MR (37.3% vs. 31.4%, P = 0.53). Overall, a significantly higher incidence of instability was found in Group H compared to Group NH (77.3% vs .37.3%, P < 0 .001*).

CONCLUSIONS

DLS with a high intensity within the interspinous ligaments is a distinct subgroup associated with segmental instability, the combination of 5R-STS and S-MR should be regarded as the most clinically relevant approach for assessing OFI and lumbar instability.

Clinical Utility of an Intervertebral Motion Metric for Deciding on the Addition of Instrumented Fusion in Degenerative Spondylolisthesis

STUDY DESIGN

A prospective single-arm clinical study.

OBJECTIVE

To explore the clinical utility of an intervertebral motion metric by determining the proportion of patients for whom it changed their surgical treatment plan from decompression only to decompression with fusion or vice versa .

SUMMARY OF BACKGROUND DATA

Lumbar spinal stenosis from degenerative spondylolisthesis is commonly treated with decompression only or decompression with additional instrumented fusion. An objective diagnostic tool capable of establishing abnormal motion between lumbar vertebrae to guide decision-making between surgical procedures is needed. To this end, a metric based on the vertebral sagittal plane translation-per-degree-of-rotation calculated from flexion-extension radiographs was developed.

MATERIALS AND METHODS

First, spine surgeons documented their intended surgical plan. Subsequently, the participants' flexion-extension radiographs were taken. From these, the translation-per-degree-of-rotation was calculated and reported as a sagittal plane shear index (SPSI). The SPSI metric of the spinal level intended to be treated was used to decide if the intended surgical plan needed to be changed or not.

RESULTS

SPSI was determined for 75 participants. Of these, 51 (68%) had an intended surgical plan of decompression only and 24 (32%) had decompression with fusion. In 63% of participants, the SPSI was in support of their intended surgical plan. For 29% of participants, the surgeon changed the surgical plan after the SPSI metric became available to them. A suggested change in the surgical plan was overruled by 8% of participants. The final surgical plan was decompression only for 59 (79%) participants and decompression with fusion for 16 (21%) participants.

CONCLUSION

The 29% change in intended surgical plans suggested that SPSI was considered by spine surgeons as an adjunct metric in deciding whether to perform decompression only or to add instrumented fusion. This change exceeded the a priori defined 15% considered necessary to show the potential clinical utility of SPSI.

Dynamic Instability Is Underestimated on Standing Flexion-Extension Films When Compared With Prone CT Imaging

STUDY DESIGN/SETTING

Single center retrospective cohort study.

OBJECTIVE

We performed a retrospective study evaluating the incidence and degree of L4-5 anterior spondylolisthesis in patients with standard supine MRI, standing flexion-extension radiographs, and prone CT. We hypothesize that prone CT imaging will provide greater sensitivity for instability compared with conventional flexion extension or supine positions.

SUMMARY OF BACKGROUND DATA

Dynamic lumbar instability evaluated by flexion-extension radiographs may underestimate the degree of lumbar spondylolisthesis. Despite efforts to characterize dynamic instability, significant variability remains in current guidelines regarding the most appropriate imaging modalities to adequately evaluate instability.

METHODS

We assessed single-level (L4-5) anterolisthesis between 2014 and 2022 with standing lateral conventional radiographs (CR), flexion-extension images, prone CT images (CT), or supine MRI images (MRI).

RESULTS

We identified 102 patients with L4-5 anterolisthesis. The average translation (±SD) measured were 4.9±2.2 mm (CR), 2.5±2.6 mm (CT), and 3.7±2.6 mm (MRI) (P<0.001). The mean difference in anterolisthesis among imaging modalities was 2.7±1.8 mm between CR and CT (P<0.001), 1.8±1.4 mm between CR and MRI (P<0.001), and 1.6±1.4 mm between CT and MRI (P=0.252). Ninety-two of 102 patients (90.2%) showed greater anterolisthesis on CR compared with CT, 72 of 102 (70.6%) comparing CR to MRI, and 27 of 102 (26.5%) comparing CT to MRI. We found that 17.6% of patients exhibited ≥3 mm anterior translation comparing CR with MRI, whereas 38.2% of patients were identified comparing CR with CT imaging (χ2 test P=0.0009, post hoc Fisher exact test P=0.0006 between CR and CT). Only 5.9% of patients had comparable degrees of instability between flexion-standing.

CONCLUSIONS

Prone CT imaging revealed the greatest degree of single L4-5 segmental instability compared with flexion-extension radiographs.

Reliability of facet fluid on preoperative MRI for prediction of segmental instability after decompression surgery for degenerative lumbar spinal stenosis

BACKGROUND

The purpose of this study is to determine whether preoperative facet fluid on MRI can help predict segmental instability (SI) after decompression surgery.

METHODS

We analyzed 34 patients (14 men and 20 women, a total of 37 segments) who underwent decompression for degenerative lumbar spinal stenosis from June 2011 to August 2019 at a single institution. Mean age at the time of operation was 67.8. Postoperative assessment was performed uniformly 12 months (11~15 months) after the surgery. Preoperative facet fluid on MRI, pre- and postoperative slip percentage, and segmental motion on lumbar lateral neutral and flexion-extension (LFE) radiographic images were measured. Visual Analog Scale (VAS) and necessities of interventional procedure or medication was also assessed for clinical outcomes.

RESULTS

No significant association was found between preoperative facet fluid indices and pre- or postoperative slip percentage (P=0.134) and segmental motion (P=0.936). There were no significant association also between facet fluid indices and VAS of back or leg (P=0.997 and P=0.437 respectively).

CONCLUSIONS

Preoperative facet fluid is not a predictive index of postoperative segmental instability or clinical outcome. Without segmental instability on LFE radiographic images, the presence of facet fluid in MRI is not an absolute indication for fusion.

Decompression alone or decompression with fusion for lumbar spinal stenosis: five-year clinical results from a randomized clinical trial

Aims

We compared decompression alone to decompression with fusion surgery for lumbar spinal stenosis, with or without degenerative spondylolisthesis (DS). The aim was to evaluate if five-year outcomes differed between the groups. The two-year results from the same trial revealed no differences.

Methods

The Swedish Spinal Stenosis Study was a multicentre randomized controlled trial with recruitment from September 2006 to February 2012. A total of 247 patients with one- or two-level central lumbar spinal stenosis, stratified by the presence of DS, were randomized to decompression alone or decompression with fusion. The five-year Oswestry Disability Index (ODI) was the primary outcome. Secondary outcomes were the EuroQol five-dimension questionnaire (EQ-5D), visual analogue scales for back and leg pain, and patient-reported satisfaction, decreased pain, and increased walking distance. The reoperation rate was recorded.

Results

Five-year follow-up was completed by 213 (95%) of the eligible patients (mean age 67 years; 155 female (67%)). After five years, ODI was similar irrespective of treatment, with a mean of 25 (SD 18) for decompression alone and 28 (SD 22) for decompression with fusion (p = 0.226). Mean EQ-5D was higher for decompression alone than for fusion (0.69 (SD 0.28) vs 0.59 (SD 0.34); p = 0.027). In the no-DS subset, fewer patients reported decreased leg pain after fusion (58%) than with decompression alone (80%) (relative risk (RR) 0.71 (95% confidence interval (CI) 0.53 to 0.97). The frequency of subsequent spinal surgery was 24% for decompression with fusion and 22% for decompression alone (RR 1.1 (95% CI 0.69 to 1.8)).

Conclusion

Adding fusion to decompression in spinal stenosis surgery, with or without spondylolisthesis, does not improve the five-year ODI, which is consistent with our two-year report. Three secondary outcomes that did not differ at two years favoured decompression alone at five years. Our results support decompression alone as the preferred method for operating on spinal stenosis.

Differences in upper body posture between patients with lumbar spine syndrome and healthy individuals under the consideration of sex, age and BMI

BACKGROUND

Work-related forced postures, such as prolonged standing work, can lead to complaints in the lower back. Current research suggests that there is increased evidence of associations between patients with low back pain (LBP) and reduced lordosis in the lumbar spine and generally less spinal tilt in the sagittal plane. The aim of this study is to extend the influence of LBP to other parameters of upper body posture in standing, taking into account the rotational and frontal planes.

METHODS

The study included a no-LBP group (418 males, 412 females, aged 21-65 years) and an LBP group (138 subjects: 80 females, 58 males, aged 18-86 years) with medically diagnosed lumbar spine syndrome (LSS). The "ABW BodyMapper" back scanner from ABW GmbH in Germany was used for posture assessment using video raster stereography. Statistical analyses employed two-sample t-tests or Wilcoxon-Mann-Whitney-U tests to assess the relationship between the LBP/no-LBP groups and back posture parameters. Linear and logarithmic regressions were used with independent variables including group, sex, height, weight and body mass index (BMI). Significance level: α = 0.05 (95% confidence).

RESULTS

The regression analysis showed that sagittal parameters of the spine (sagittal trunk decline, thoracic and lumbar bending angle, kyphosis and lordosis angles) depend primarily on sex, age, BMI, height and/or weight but not on group membership (LBP/no-LBP). In the shoulder region, a significant dependency between group membership and scapular rotation was found. In the pelvic region, there were only significant dependencies in the transverse plane, particularly between pelvic torsion and BMI, weight, height and between pelvic rotation and group membership, age and sex.

CONCLUSION

No difference between the patients and healthy controls were found. In addition, sex appears to be the main influencing factor for upper body posture. Other influencing factors such as BMI, height or weight also seem to have a significant influence on upper body posture more frequently than group affiliation.

How Do Standing Neutral, Supine Lateral, Standing Flexion, and Standing Extension Radiographs Compare in Detecting the Presence and Magnitude of Stable and Dynamic Spondylolisthesis?

BACKGROUND

Clinical guidelines recommend standing radiographs as the most appropriate imaging for detecting degenerative spondylolisthesis, although reliable evidence about the standing position is absent. To our knowledge, no studies have compared different radiographic views and pairings to detect the presence and magnitude of stable and dynamic spondylolisthesis.

QUESTIONS/PURPOSES

(1) What is the percentage of new patients presenting with back or leg pain with stable (3 mm or greater listhesis on standing radiographs) and dynamic (3 mm or greater listhesis difference on standing-supine radiographs) spondylolisthesis? (2) What is the difference in the magnitude of spondylolisthesis between standing and supine radiographs? (3) What is the difference in the magnitude of dynamic translation among flexion-extension, standing-supine, and flexion-supine radiographic pairs?

METHODS

This cross-sectional, diagnostic study was performed at an urban, academic institution between September 2010 and July 2016; 579 patients 40 years or older received a standard radiographic three-view series (standing AP, standing lateral, and supine lateral radiographs) at a new patient visit. Of those individuals, 89% (518 of 579) did not have any of the following: history of spinal surgery, evidence of vertebral fracture, scoliosis greater than 30°, or poor image quality. In the absence of a reliable diagnosis of dynamic spondylolisthesis using this three-view series, patients may have had flexion and extension radiographs, and approximately 6% (31 of 518) had flexion and extension radiographs. A total of 53% (272 of 518) of patients were female, and the patients had a mean age of 60 ± 11 years. Listhesis distance (in mm) was measured by two raters as displacement of the posterior surface of the superior vertebral body in relation to the posterior surface of the inferior vertebral body from L1 to S1; interrater and intrarater reliability, assessed with intraclass correlation coefficients, was 0.91 and 0.86 to 0.95, respectively. The percentage of patients with and the magnitude of stable spondylolisthesis was estimated on and compared between standing neutral and supine lateral radiographs. The ability of common pairs of radiographs (flexion-extension, standing-supine, and flexion-supine) to detect dynamic spondylolisthesis was assessed. No single radiographic view or pair was considered the gold standard because stable or dynamic listhesis on any radiographic view is often considered positive in clinical practice.

RESULTS

Among 518 patients, the percentage of patients with spondylolisthesis was 40% (95% CI 36% to 44%) on standing radiographs alone, and the percentage of patients with dynamic spondylolisthesis was 11% (95% CI 8% to 13%) on the standing-supine pair. Standing radiographs detected greater listhesis than supine radiographs did (6.5 ± 3.9 mm versus 4.9 ± 3.8 mm, difference 1.7 mm [95% CI 1.2 to 2.1 mm]; p < 0.001). Among 31 patients, no single radiographic pairing identified all patients with dynamic spondylolisthesis. The listhesis difference detected between flexion-extension was no different from the listhesis difference detected between standing-supine (1.8 ± 1.7 mm versus 2.0 ± 2.2 mm, difference 0.2 mm [95% CI -0.5 to 1.0 mm]; p = 0.53) and flexion-supine (1.8 ± 1.7 mm versus 2.5 ± 2.2 mm, difference 0.7 mm [95% CI 0.0 to 1.5]; p = 0.06).

CONCLUSION

This study supports current clinical guidelines that lateral radiographs should be obtained with patients in the standing position, because all cases of stable spondylolisthesis of 3 mm or greater were detected on standing radiographs alone. Each radiographic pair did not detect different magnitudes of listhesis, and no single pair detected all cases of dynamic spondylolisthesis. Clinical concern for dynamic spondylolisthesis may justify standing neutral, supine lateral, standing flexion, and standing extension views. Future studies could identify and evaluate a set of radiographic views that provides the greatest capacity to diagnose stable and dynamic spondylolisthesis.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Utility of Seated Lateral Radiographs in the Diagnosis and Classification of Lumbar Degenerative Spondylolisthesis

STUDY DESIGN

Retrospective cohort study.

PURPOSE

Our goal was to determine which radiographic images are most essential for degenerative spondylolisthesis (DS) classification and instability detection.

OVERVIEW OF LITERATURE

The heterogeneity in DS requires multiple imaging views to evaluate vertebral translation, disc space, slip angle, and instability. However, there are several restrictions on frequently used imaging perspectives such as flexion-extension and upright radiography.

METHODS

We assessed baseline neutral upright, standing flexion, seated lateral radiographs, and magnetic resonance imaging (MRI) for patients identified with spondylolisthesis from January 2021 to May 2022 by a single spine surgeon. DS was classified by Meyerding and Clinical and Radiographic Degenerative Spondylolisthesis classifications. A difference of >10° or >8% between views, respectively, was used to characterize angular and translational instability. Analysis of variance and paired chi-square tests were utilized to compare modalities.

RESULTS

A total of 136 patients were included. Seated lateral and standing flexion radiographs showed the greatest slip percentage (16.0% and 16.7%), while MRI revealed the lowest (12.2%, p <0.001). Standing flexion and lateral radiographs when seated produced more kyphosis (4.66° and 4.97°, respectively) than neutral upright and MRI (7.19° and 7.20°, p <0.001). Seated lateral performed similarly to standing flexion in detecting all measurement parameters and categorizing DS (all p >0.05). Translational instability was shown to be more prevalent when associated with seated lateral or standing flexion than when combined with neutral upright (31.5% vs. 20.2%, p =0.041; and 28.1% vs. 14.6%, p =0.014, respectively). There were no differences between seated lateral or standing flexion in the detection of instability (all p >0.20).

CONCLUSIONS

Seated lateral radiographs are appropriate alternatives for standing flexion radiographs. Films taken when standing up straight do not offer any more information for DS detection. Rather than standing flexion-extension radiographs, instability can be detected using an MRI, which is often performed preoperatively, paired with a single seated lateral radiograph.

Radiological Definitions of Sagittal Plane Segmental Instability in the Degenerative Lumbar Spine - A Systematic Review

STUDY DESIGN

Systematic Review.

OBJECTIVE

To collect and group definitions of segmental instability, reported in surgical studies of patients with lumbar spinal stenosis (LSS) and/or lumbar degenerative spondylolisthesis (LDS). To report the frequencies of these definitions. To report on imaging measurement thresholds for instability in patients and compare these to those reported in biomechanical studies and studies of spine healthy individuals.To report on studies that include a reliability study.

METHODS

This review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Studies eligible for inclusion were clinical and biomechanical studies on adult patients with LDS and/or LSS who underwent surgical treatment and had data on diagnostic imaging. A systematic literature search was conducted in relevant literature databases. Full text screening inclusion criteria was definition of segmental instability or any synonym. Two reviewers independently screened articles in a two-step process. Data synthesis presented by tabulate form and narrative synthesis.

RESULTS

We included 118 studies for data extraction, 69% were surgical studies with decompression or fusion as interventions, 31% non-interventional studies. Grouping the definitions of segmental instability according similarities showed that 24% defined instability by dynamic sagittal translation, 26% dynamic translation and dynamic angulation, 8% used a narrative definition. Comparison showed that non-interventional studies with a healthy population more often had a narrative definition.

CONCLUSION

Despite a reputation of non-consensus, segmental instability in the degenerative lumbar spine can radiologically be defined as > 3 mm dynamic sagittal translation.

Instability Missed by Flexion-Extension Radiographs Subsequently Identified by Alternate Imaging in L4-L5 Lumbar Degenerative Spondylolisthesis

STUDY DESIGN

Cross-sectional preoperative and intraoperative imaging study of L4-L5 lumbar degenerative spondylolisthesis (LDS).

OBJECTIVE

To determine if alternate imaging modalities would identify LDS instability that did not meet the criteria for instability based on comparison of flexion and extension radiographs.

SUMMARY OF BACKGROUND DATA

Pain may limit full flexion and extension maneuvers and thereby lead to underreporting of true dynamic translation and angulation in LDS. Alternate imaging pairs may identify instability missed by flexion-extension.

MATERIALS AND METHODS

Consecutive patients scheduled for surgery for single-level L4-L5 LDS had preoperative standing radiographs in the lateral, flexion, and extension positions, supine computed tomography (CT) scans, and intraoperative fluoroscopic images in the supine and prone positions after anesthesia but before incision. Instability was defined as translation ≥3.5 mm or angulation ≥11° between the following pairs of images: (1) flexion-extension; (2) CT-lateral; (3) lateral-intraoperative supine; (4) lateral-intraoperative prone; and (5) intraoperative supine-prone.

RESULTS

Of 240 patients (mean age 68 y, 54% women) 15 (6%) met the criteria for instability by flexion-extension, and 225 were classified as stable. Of these 225, another 84 patients (35% of total enrollment) were reclassified as unstable by comparison of CT-lateral images (21 patients) and by lateral-intraoperative images (63 patients). Nine of the 15 patients diagnosed with instability by flexion-extension had fusion (60%), and 68 of the 84 patients reclassified as unstable by other imaging pairs had fusion (81%) ( P =0.07). The 84 reclassified patients were more likely to undergo fusion compared with the 141 patients who persistently remained classified as stable (odds ratio=2.6, 95% CI: 1.4-4.9, P =0.004).

CONCLUSIONS

Our study provides evidence that flexion and extension radiographs underreport the dynamic extent of LDS and therefore should not be solely relied upon to ascertain instability. These findings have implications for how instability should be established and the extent of surgery that is indicated.

Utility of Flexion-Extension Radiographs with Brackets and Magnetic Resonance Facet Fluid for the Assessment of Lumbar Instability in Degenerative Lumbar Spondylolisthesis

OBJECTIVE

To propose a new standardized technique for evaluating lumbar stability in degenerative lumbar spondylolisthesis using lumbar lateral flexion-extension radiographs with brackets and magnetic resonance facet fluid.

METHODS

A retrospective analysis of 57 patients diagnosed with lumbar (L4-5) spondylolisthesis was performed. We analyzed lateral flexion-extension radiographs obtained with a bracket (LFEB) and without a bracket (LFE). Sagittal translation, segmental angulation, posterior opening, lumbar instability, and changes in lumbar lordosis were compared using functional radiographs. The mean width and maximum width of the facet fluid, mean facet joint length, and facet fluid index (FFI) of the 2 groups were compared using sagittal translation.

RESULTS

The average value of sagittal translation was 1.68 ± 0.96 mm in LFE and 3.07 ± 1.29 mm in LFEB, and the difference was significant (P < 0.05). Segmental angulation, posterior opening, and changes in lumbar lordosis were significantly greater in LFEB than in LFE. The instability detection rate was 14.0% in LFE and 35.1% in LFEB. The FFI, maximum width, and mean width were significantly increased in the unstable lumbar spondylolisthesis group compared with the stable group in LFEB. The FFI and maximum width of the facet fluid were significantly increased in the unstable lumbar spondylolisthesis group compared with the stable group in LFE.

CONCLUSIONS

Lumbar lateral flexion-extension radiographs with brackets can standardize the operation process and provide sufficient hyperflexion and hyperextension images. The width of the facet fluid and FFI are significant factors in the evaluation of lumbar stability in patients with lumbar spondylolisthesis.

Analysis of Chronic Low Back Pain Caused by Lumbar Microinstability After Percutaneous Endoscopic Transforaminal Discectomy: A Retrospective Study

Objective

Chronic low back pain (CLBP) after percutaneous endoscopic transforaminal discectomy (PTED) surgery may be caused by preoperative lumbar microinstability (MI). However, there is a paucity of research on the relationship between lumbar microinstability and chronic low back pain. The purpose of this article is to assess the preoperative radiographic characteristics of patients and evaluate the effects of lumbar microinstability on patient-reported outcomes among single-level lumbar disc herniation (LDH) patients who underwent PTED.

Methods

This study retrospectively reviewed the radiographic characteristics of a consecutive series of 127 patients with low back pain and leg pain caused by single-level LDH underwent PTED from August 2018 to March 2021. They were divided into three groups according to the radiographic parameters: the stable group (Group S), the dysfunctional group (Group D), and the microinstability group (Group M). The visual analogue scale (VAS) scores for leg and low back pain and Oswestry Disability Index (ODI) were evaluated preoperatively and postoperatively. Logistic regression analysis was used to identify independent risk factors for CLBP.

Results

Compared with Group D and Group S, Group M had the highest ODI scores (P < 0.01) and VAS scores (low back pain) (P < 0.01) after 1 year, while there were no significant differences in the VAS scores for leg pain at different time points after surgery (P > 0.05). In addition, the logistic regression analysis results regarding CLBP revealed that muscle fatty degeneration on MRI (95% CI, 1.20-8.51, P = 0.02), and facet tropism (95% CI, 1.39 -11.37, P = 0.01) may be independent risk factors.

Conclusion

Patients with lumbar microinstability may have CLBP after PTED, so patients with lumbar microinstability may need to take internal fixation surgery to solve their symptoms.

Intermodal Detection of Lumbar Instability in Degenerative Spondylolisthesis is Superior to Functional Radiographs

Purpose

In this study, we compare different imaging modalities to find the most sensitive and efficient way of detecting instability in lumbar spondylolisthesis.

Methods

Patients presenting with spondylolisthesis from June 01, 2018 to May 31, 2020 with functional radiographs and either CT scans or MRI images were included in our single-center retrospective cohort study. The amount of translation, in millimeters, was measured on supine MRI images, CT scans, and radiographs of inclination while sitting, standing, or prone and reclination while standing using the Meyerding technique. The amount of translation was compared among the different modalities.

Results

A total of 113 patients with spondylolisthesis on 125 vertebral levels were included in this study. The mean patient age was 73.52 ± 12.59 years; 69 (60.5%) patients were females. The most affected level was L4/5 (62.4%), followed by L3/4 (16%) and L5/S1 (13.6%). The average translations measured on supine CT were 4.13 ± 5.93 mm and 4.42 ± 3.49 mm on MRI (p = 0.3 for the difference between MRI and CT). The difference of inclination while sitting radiograph to slice imaging was 3.37 ± 3.64 mm (p < 0.0001), inclination while standing to slice imaging was 2.67 ± 3.03 mm (p < 0.0001), reclination while standing to slice imaging was 1.6 ± 3.15 mm (p = 0.03), and prone to slice imaging was 2.19 ± 3.02 mm (p = 0.03).

Conclusion

We found that a single radiograph in either inclination, reclination, or prone position compared to a CT scan or an MRI image in supine position can detect instability in spondylolisthesis more efficiently than comparison of functional radiographs in any position.

Utility of the decubitus or the supine rather than the extension lateral radiograph in evaluating lumbar segmental instability

OBJECTIVE

To determine the superiority of decubitus and supine radiographs for the reduction of olisthesis instead of the extension radiograph, and the inconsistency of the CT scout view, 3D-reconstruction and MR image in evaluating segmental instability.

METHODS

A cohort of 154 low-grade lumbar degenerative spondylolisthesis patients with the average age of (60.9 ± 8.6) years were enrolled. Slip percentage was measured on the flexion, upright and extension radiographs, the decubitus lateral radiograph, CT scout view, the supine median sagittal 3D-reconstruction and MR image. The translational range of motion was calculated, and segmental instability was defined as translational motion ≥ 8%.

RESULTS

The flexion radiograph showed higher slip percentage than upright radiograph (p < 0.001). The slip percentage of the MR image was lower than CT scout view (p = 0.003) and CT sagittal radiograph (p = 0.001) on the basis of statistical differences among three groups (p = 0.002). The slip percentage of the CT scout view, decubitus radiograph, and extension radiograph was statistically different (p = 0.01). The CT scout view and sagittal reconstruction had lower slip percentage than the extension radiograph (p = 0.042; p = 0.003, respectively). Both the flexion-supine and flexion-decubitus modality had larger translational motion than the flexion-extension modality (p = 0.007; p < 0.001, respectively).

CONCLUSION

Many modalities and techniques are used to show the vertebral displacement and its possible change and any cane used in the daily practice. In this study, supine and decubitus lateral radiography have larger reduction of olisthesis than the extension radiograph. The flexion radiograph coupled with a supine or decubitus radiograph reveals greater mobility than the flexion-extension modality.

Lumbar Spinal Stenosis with Degenerative Spondylolisthesis Treated with Decompression Alone. A Cohort of 346 Patients at a Large Spine Unit. Clinical Outcome, Complications and Subsequent Surgery

STUDY DESIGN

Cohort study.

OBJECTIVE

To study the clinical outcome, complications and subsequent surgery rate of DA for lumbar spinal stenosis (LSS) with DS.

SUMMARY OF BACKGROUND DATA

There is still no consensus regarding the treatment approach for LSS with DS.

METHODS

We performed a retrospectively designed cohort study on prospectively collected data from a single high productive spine surgical center. Results from the Swedish Spine Registry and a local register for complications were used for the analyses. Patients with LSS and DS (>3 mm) who underwent DA during January 2012 to August 2017 were included. Patient reported outcome measures at baseline and 2 years after surgery were analyzed. Complications within 30 days of surgery and all subsequent surgery in the lumbar spine were registered.

RESULTS

We identified and included 346 patients with completed 2-year follow-up registration. At 2-year follow-up there was a significant improvement in all outcome measures. The global assessment success rate for back and leg pain was 68.3% and 67.6% respectively. Forty-one patients had at least 1 intra- or postoperative complication (11.9%). Nine patients (2.6%), underwent subsequent surgery within 2 years of the primary surgery whereof 2 underwent fusion. During the whole period of data collection, that is, as of June 2020, 28 patients had undergone subsequent surgery (8.1%) whereas 8 of them had had 2 surgeries. Fifteen patients underwent fusion.

CONCLUSION

DA provides good clinical outcome at 2-year follow-up in patients with LSS and DS with low rate of intra- and postoperative complications and subsequent surgery. Our data supports the evidence that DA is effective and safe for LSS with DS.Level of Evidence: 3.

ACR Appropriateness Criteria® Low Back Pain: 2021 Update

In the United States, acute low back pain, with or without radiculopathy, is the leading cause of years lived with disability and the third ranking cause of disability-adjusted life-years. Uncomplicated acute low back pain and/or radiculopathy is a benign, self-limited condition that does not warrant any imaging studies. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. It is also considered for those patients presenting with red flags, raising suspicion for a serious underlying condition, such as cauda equina syndrome, malignancy, fracture, or infection. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Lumbar spondylolisthesis: STATE of the art on assessment and conservative treatment

INTRODUCTION

There is weak relationship between the presence of lumbar spondylolisthesis [SPL] and low back pain that is not always associated with instability, either at the involved lumbar segment or at different spinal levels. Therefore patients with lumbar symptomatic SPL can be divided into stable and unstable, based on the level of mobility during flexion and extension movements as general classifications for diagnostic and therapeutic purposes. Different opinions persist about best treatment (conservative vs. surgical) and among conservative treatments, on the type, dosage, and progression of physical therapy procedures.

PURPOSE AND IMPORTANCE TO PRACTICE

The aim of this Masterclass is to provide clinicians evidence-based indications for assessment and conservative treatment of SPL, taking into consideration some subgroups related to specific clinical presentations.

CLINICAL IMPLICATIONS

This Masterclass addresses the different phases of the assessment of a patient with SPL, including history, imaging, physical exam, and questionnaires on disability and cognitive-behavioral components. Regarding conservative treatment, self- management approaches and graded supervised training, including therapeutic relationships, information and education, are explained. Primary therapeutic procedures for pain control, recovery of the function and the mobility through therapeutic exercise, passive mobilization and antalgic techniques are suggested. Moreover, some guidance is provided on conservative treatment in specific clinical presentations (lumbar SPL with radiating pain and/or lumbar stenosis, SPL complicated by other factors, and SPL in adolescents) and the number/duration of sessions.

FUTURE RESEARCH PRIORITIES

Some steps to improve the diagnostic-therapeutic approach in SPL are to identify the best cluster of clinical tests, define different lumbar SPL subgroups, and investigate the effects of treatments based on that classification, similarly to the approach already proposed for non-specific LBP.

Is There Additional Value to Flexion-Extension Radiographs for Degenerative Spondylolisthesis?

STUDY DESIGN

Multicenter retrospective study.

OBJECTIVE

Flexion-extension radiographs are frequently used to assess motion in patients with degenerative spondylolisthesis. However, they expose patients to additional radiation and increase cost. The aim of this study is to determine if flexion-extension radiographs provide additional information not seen on upright neutral radiographs and supine magnetic resonance imaging (MRI) that may guide surgical decision making.

SUMMARY OF BACKGROUND DATA

Supine MRI and upright neutral radiographs are routinely performed in patients with degenerative spondylolisthesis. It is unclear whether additional flexion-extension views play a significant role in surgical planning for this patient population.

METHODS

From the Quality Outcomes Database, patients who had surgery for grade 1 degenerative spondylolisthesis were identified. Magnitude of slip on pre-op supine MRI, upright neutral, flexion, and extension radiographs were measured. Additional motion was defined as 3 mm or more slip difference between radiographs. For the purpose of this analysis, patients with a slip of 7 mm or more on upright neutral radiographs were assumed to require a fusion.

RESULTS

A total of 191 patients were identified. Mean age was 61.6 years (114 females, 60%). Only 31 patients (16%) had additional motion on flexion-extension views not seen on upright neutral x-rays versus supine MRI. Of these 31 patients, 19 had slips less than 7 mm on upright x-ray, generating equipoise for fusion.

CONCLUSION

Flexion-extension radiographs may play a limited role in management of degenerative spondylolisthesis. The subset of patients for which flexion-extension views were most likely to provide value were patients with smaller slips (<7 mm) with no evidence of motion on standing radiographs versus MRI. In 90% of spondylolisthesis cases, information used for surgical planning may be ascertained by comparing motion between supine MRI and upright lateral radiographs.Level of Evidence: 3.

Utility of Natural Sitting Lateral Radiograph in the Diagnosis of Segmental Instability for Patients with Degenerative Lumbar Spondylolisthesis

BACKGROUND

Segmental instability in patients with degenerative lumbar spondylolisthesis is an indication for surgical intervention. The most common method to evaluate segmental mobility is lumbar standing flexion-extension radiographs. Meanwhile, other simple radiographs, such as standing upright radiograph, a supine sagittal magnetic resonance imaging (MRI) or supine lateral radiograph, or a slump or natural sitting lateral radiograph, have been reported to diagnose segmental instability. However, those common posture radiographs have not been well characterized in one group of patients. Therefore, we measured slip percentage in a group of patients with degenerative lumbar spondylolisthesis using radiographs of patients in standing upright, natural sitting, standing flexion, and standing extension positions as well as supine MRI.

QUESTIONS/PURPOSES

We asked: (1) Does the natural sitting radiograph have a larger slip percentage than the standing upright or standing flexion radiograph? (2) Does the supine sagittal MRI reveal a lower slip percentage than the standing extension radiograph? (3) Does the combination of the natural sitting radiograph and the supine sagittal MRI have a higher translational range of motion (ROM) and positive detection rate of translational instability than traditional flexion-extension mobility using translational instability criteria of greater than or equal to 8%?

METHODS

We retrospectively performed a study of 62 patients (18 men and 44 women) with symptomatic degenerative lumbar spondylolisthesis at L4 who planned to undergo a surgical intervention at our institution between September 2018 and June 2019. Each patient underwent radiography in the standing upright, standing flexion, standing extension, and natural sitting positions, as well as MRI in the supine position. The slip percentage was measured three times by single observer on these five radiographs using Meyerding's technique (intraclass correlation coefficient 0.88 [95% CI 0.86 to 0.90]). Translational ROM was calculated by absolute values of difference between two radiograph positions. Based on the results of comparison of slip percentage and translational ROM, we developed the diagnostic algorithm to evaluate segmental instability. Also, the positive rate of translational instability using our diagnostic algorithms was compared with traditional flexion-extension radiographs.

RESULTS

The natural sitting radiograph revealed a larger mean slip percentage than the standing upright radiograph (21% ± 7.4% versus 17.7% ± 8.2%; p < 0.001) and the standing flexion radiograph (21% ±7.4% versus 18% ± 8.4%; p = 0.002). The supine sagittal MRI revealed a lower slip percentage than the standing extension radiograph (95% CI 0.49% to 2.8%; p = 0.006). The combination of natural sitting radiograph and the supine sagittal MRI had higher translational ROM than the standing flexion and extension radiographs (10% ± 4.8% versus 5.4% ± 3.7%; p < 0.001). More patients were diagnosed with translational instability using the combination of natural sitting radiograph and supine sagittal MRI than the standing flexion and extension radiographs (61% [38 of 62] versus 19% [12 of 62]; odds ratio 3.9; p < 0.001).

CONCLUSION

Our results indicate that a sitting radiograph reveals high slip percentage, and supine sagittal MRI demonstrated a reduction in anterolisthesis. The combination of natural sitting and supine sagittal MRI was suitable to the traditional flexion-extension modality for assessing translational instability in patients with degenerative lumbar spondylolisthesis.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Flexion-extension standing radiographs underestimate instability in patients with single-level lumbar spondylolisthesis: comparing flexion-supine imaging may be more appropriate

BACKGROUND

Generally, most spine surgeons agree that increased segmental motion viewed on flexion-extension radiographs is a reliable predictor of instability; however, these views can be limited in several ways and may underestimate the instability at a given lumbar segment.

METHODS

Consecutively collected adult (≥18 years old) patients with symptomatic single-level lumbar spondylolisthesis were reviewed from a two-surgeon database from 2015 to 2019. Routine standing lumbar X-rays (neutral, flexion, extension) and supine lumbar MRI (sagittal T2-weighted imaging sequence) were performed. Patients were excluded if they had prior lumbar surgery, missing radiographic data, or if the time between X-rays and MRI was >6 months.

RESULTS

All 39 patients with symptomatic, single-level lumbar spondylolisthesis were identified. The mean age was 57.3±16.7 years and 66% were female. There was good intra- and inter-rater reliability agreement between measured values on the presence of instability. The slip percentage (SP) difference was significantly highest in the flexion-supine (FS) (5.7 mm, 12.3%) and neutral standing-supine (NS) (4.3 mm, 8.7%) groups, both of which were significantly higher compared with the flexion-extension (FE) group (1.8 mm, 4.5%, P<0.001). Ventral instability based on SP >8% was observed more frequently in FS (79.5%) and NS (52.6%) groups compared with FE group (16.7%, P<0.001). No statistically significant correlation was found between SP and disc angle for all radiographic views.

CONCLUSIONS

Comparing standing lateral and flexion X-rays with supine MRIs provides higher sensitivity to assess instability than standard flexion-extension radiographs. The FS and NS comparisons also show greater slip percentage differences at higher slip grades, but not at different lumbar levels. These changes are not dependent on age or gender.

Analysis of translation and angular motion in loaded and unloaded positions in the lumbar spine

Background Context

Abnormalities in intervertebral rotation and translation are important to diagnosis and treatment planning for common spinal disorders. Tests that do not sufficiently load the spine can result in mis-diagnosed motion abnormalities. Upright flexion and extension x-rays are commonly used despite known limitations. Additional evidence is needed in support of preliminary studies suggesting that the change from standing to supine may sufficiently stress the spine to diagnose motion abnormalities.

Purpose

Compare intervertebral translation between flexion and extension to translation between upright and supine positions in a representative clinical population.

Study Design/Setting

Prospective analysis of images retrospectively collected from routine clinical practices.

Methods

After obtaining IRB approval for analysis of previously obtained images, patients were identified via chart reviews where a neutral-lateral x-ray and an MRI or CT exam were obtained for diagnosis of a spinal disorder and where flexion-extension x-rays had been obtained to help diagnose abnormal intervertebral motion. The mid-sagittal slice from the MRI or CT exam was paired with the neutral-lateral radiograph. Intervertebral translation at the L4-L5 and L5-S1 levels between supine and standing and between flexion and extension were measured from the images using previously validated methods. The translations were classified as normal or abnormal with reference to a previously obtained database of intervertebral motion in radiographically normal and asymptomatic volunteers.

Results

At the L5-S1 level in particular, there tended to be greater translation between the supine and standing than between upright flexion and extension. On average, translations were below that found in asymptomatic volunteers. No abnormal translations were detected from flexion-extension radiographs whereas approximately 7% of levels had abnormal translations between supine and upright positions.

Conclusions

Intervertebral translations between supine and standing, measured using the mid-sagittal slice from a MRI or CT exam and a lateral x-ray with the patient standing can help to identify abnormal motion. This would be particularly valuable for patients with limited flexion and extension. This study thereby adds to the evidence in support of measuring intervertebral motion between the supine and upright positions to detect abnormal intervertebral motion.

Predicting spondylolisthesis correction with prone traction radiographs

Aims

To determine the effectiveness of prone traction radiographs in predicting postoperative slip distance, slip angle, changes in disc height, and lordosis after surgery for degenerative spondylolisthesis of the lumbar spine.

Methods

A total of 63 consecutive patients with a degenerative spondylolisthesis and preoperative prone traction radiographs obtained since 2010 were studied. Slip distance, slip angle, disc height, segmental lordosis, and global lordosis (L1 to S1) were measured on preoperative lateral standing radiographs, flexion-extension lateral radiographs, prone traction lateral radiographs, and postoperative lateral standing radiographs. Patients were divided into two groups: posterolateral fusion or posterolateral fusion with interbody fusion.

Results

The mean changes in segmental lordosis and global lordosis were 7.1° (SD 6.7°) and 2.9° (SD 9.9°) respectively for the interbody fusion group, and 0.8° (SD 5.1°) and -0.4° (SD 10.1°) respectively for the posterolateral fusion-only group. Segmental lordosis (ρ = 0.794, p < 0.001) corrected by interbody fusion correlated best with prone traction radiographs. Global lumbar lordosis (ρ = 0.788, p < 0.001) correlated best with the interbody fusion group and preoperative lateral standing radiographs. The least difference in slip distance (-0.3 mm (SD 1.7 mm), p < 0.001), slip angle (0.9° (SD 5.2°), p < 0.001), and disc height (0.02 mm (SD 2.4 mm), p < 0.001) was seen between prone traction and postoperative radiographs. Regression analyses suggested that prone traction parameters best predicted correction of slip distance (Corrected Akaike’s Information Criterion (AICc) = 37.336) and disc height (AICc = 58.096), while correction of slip angle (AICc = 26.453) was best predicted by extension radiographs. Receiver operating characteristic (ROC) cut-off showed, with 68.3% sensitivity and 64.5% specificity, that to achieve a 3.0° increase in segmental lordotic angle, patients with a prone traction disc height of 8.5 mm needed an interbody fusion.

Conclusion

Prone traction radiographs best predict the slip distance and disc height correction achieved by interbody fusion for lumbar degenerative spondylolisthesis. To achieve this maximum correction, interbody fusion should be undertaken if a disc height of more than 8.5 mm is attained on preoperative prone traction radiographs. Level of Evidence: Level II Prognostic Study Cite this article: Bone Joint J 2020;102-B(8):1062–1071.

Supplementing decompression with instrumented fusion for symptomatic lumbar spinal stenosis-a critical appraisal of available randomized controlled trials

Lumbar spinal stenosis (LSS) is one of the most common indications for surgery in the USA. The addition of instrumented fusion to decompression for the treatment of LSS has become common, but recent randomized controlled trials (RCTs) have produced percieved conflicting results with unclear clinical implications. This review seeks clarity through an analysis of available RCTs. We performed a search of the PubMed database for RCTs that directly addressed decompression vs. decompression and fusion for the surgical treatment of LSS. RCTs were screened and reviewed to compare content such as patient selection, pathology, radiographic criteria, and operative technique. Five RCTs resulted from our search and were included in our analysis. Two studies yielded class I data while three yielded class III data due to study design related issues. Heterogeneity between these studies is emphasized with regard to patient selection, LSS definition, spondylolisthesis, instability, and surgical technique. Efforts to decipher which patients will truly benefit from instrumented fusion for the surgical treatment of LSS are still ongoing. Surgeon judgment will remain a crucial component for surgical decision making until future trials provide clarity. Instrumented fusion should be tailored to the individual patient rather than incorporated as a routine practice.

Biportal endoscopic versus microscopic lumbar decompressive laminectomy in patients with spinal stenosis: a randomized controlled trial

BACKGROUND CONTEXT

Biportal endoscopic decompressive laminectomy is a widely performed procedure and shows acceptable clinical outcomes. However, the evidence regarding the advantages of biportal endoscopic surgery is weak, a randomized controlled trial is therefore warranted.

PURPOSE

To compare the clinical efficacies of biportal endoscopic and microscopic decompressive laminectomy in patients with lumbar spinal stenosis.

STUDY DESIGN

Randomized controlled trial.

PATIENT SAMPLE

Sixty-four participants suffering from low back and leg pain with single-level lumbar spinal stenosis who required decompressive laminectomy.

OUTCOME MEASURES

Outcomes were assessed with the use of patient-reported outcome measures, visual analog scale (VAS) score for low back and lower extremity radiating pain, Oswestry disability index (ODI), European Quality of Life-5 Dimensions (EQ-5D) score, and painDETECT for neuropathic pain. Surgery-related outcomes including operation time, length of hospital stay, postoperative drainage, and serum creatine phosphokinase were evaluated. Perioperative (<30 days) and late (1-12 months) complications were also noted.

METHODS

All participants were randomly assigned in a 1:1 ratio to undergo biportal endoscopic or microscopic decompressive laminectomy. The primary outcome was the ODI score at 12 months after surgery based on a modified intention-to-treat strategy. The secondary outcomes included VAS score for low back and lower extremity radiating pain, ODI scores, EQ-5D score, and painDETECT score. There were no sources of funding and no conflicts of interest associated with this study.

RESULTS

There was no significant difference between groups in the mean ODI score at 12 months after surgery (30 in the microscopy vs. 29 in the biportal endoscopy group, p=.635). There were also no significant differences in low back and lower extremity pain VAS scores, ODI, EQ-5D scores, and painDETECT scores at the 3-, 6-, or 12-month follow-up. Operation time, length of hospital stay, serum creatine phosphokinase, and perioperative complications, such as durotomies and symptomatic hematoma, showed no significant differences between the groups; however, one participant underwent additional revision surgery 9 months after the index surgery in the microscopy group.

CONCLUSIONS

Despite the study design limitation of relatively short duration of follow-up, this trial suggests that biportal endoscopic decompressive laminectomy is an alternative to and offers similar clinical outcomes as microscopic open surgery in patients with symptomatic lumbar spinal stenosis.

Do We Have Adequate Flexion-extension Radiographs for Evaluating Instability in Patients With Lumbar Spondylolisthesis?

STUDY DESIGN

A retrospective cohort study of consecutive patients.

OBJECTIVE

To investigate whether adequate flexion-extension was acquired in standard functional radiographs in lumbar spondylolisthesis.

SUMMARY OF BACKGROUND DATA

In lumbar spondylolisthesis, flexion-extension radiographs taken in the standing position are most commonly used to evaluate spinal instability. However, these functional radiographs occasionally depend on the patient's effort and cooperation, they can provide different results.

METHODS

This study included 92 consecutive patients diagnosed with L4-5 degenerative lumbar spondylolisthesis. We analyzed the flexion-extension radiographs taken with the patient being led by the hand (LH) and those taken without LH (NLH). Sagittal translation (ST), segmental angulation (SA), posterior opening (PO), and lumbar lordosis (LL) were measured on functional radiographs taken in both tests. Then, ST, SA, PO, detection rate of instability, and LL observed in LH were compared with those observed in NLH. Furthermore, the correlation of the difference was evaluated between ST, lumbar angulation, and LL.

RESULTS

A relative value of ST was 9.5% ± 4.3% in LH and 5.6% ± 3.3% in NLH, which differed significantly (P < 0.001). SA and PO were also significantly greater in LH than in NLH. The detection rate of instability was 71.7% in LH and 30.4% in NLH (P < 0.001). LL measurement on flexion showed 17.6° ± 13.5° in LH and 28.2° ± 12.2° in NLH, which differed significantly (P < 0.001). However, no significant difference was found in LL on extension between LH and NLH. There was a moderate correlation between the difference of ST, SA, PO, and LL on flexion.

CONCLUSION

Flexion with physical assistance was useful for the detection of abnormal lumbar mobility. Taking radiation exposure into consideration, physical assistance such as using a table in front of a patient could lead the similar evaluation of the segmental instability.

LEVEL OF EVIDENCE

2.

Comparison of Segmental Mobility in Lumbar Extension Radiographs between a New Technique ("Fulcrum Bending Position") and Conventional Standing Position in Spondylolisthesis Patients

Study Design

Cross-sectional study.

Purpose

This was carried out to evaluate the benefit of a ‘fulcrum bending position’ compared with the standing position for evaluation of sagittal translation and sagittal rotation in symptomatic patients with spondylolisthesis.

Overview of Literature

In lumbar X-ray, the standing position is the most common position used in determining abnormalities in lumbar movement. Lack of standardized method is one of the pitfalls in this technique. We hypothesized that the new technique, that is, fulcrum bending position, may reveal a higher translation and rotation in spondylolisthesis patients.

Methods

The extension lumbar radiographs of 36 patients with low-grade spondylolisthesis were included in the analysis and measurement. Sagittal translation and sagittal rotation were measured in both the routine standing position and in our new technique, the fulcrum bending position, which involves taking lateral cross-table images in the supine position wherein the patient lies on a cylindrical pipe to achieve maximum passive back extension by the fulcrum principle.

Results

Results of the measurement of sagittal translation in both positions revealed that compared with the extension standing position, the fulcrum bending position achieved a statistically significant increase of 1.57 mm in translation of the vertebra position (95% confidence interval [CI], 0.52–2.61; p=0.004). The measurement of sagittal rotation in both positions revealed that when compared with the extension standing position, the fulcrum bending position achieved a statistically significant increase of 3.47° in the rotation of the vertebra (95% CI, 1.64–5.30; p<0.001).

Conclusions

For evaluation of both sagittal translation and sagittal rotation in symptomatic patients with spondylolisthesis, compared with the extension standing position, the fulcrum bending position can achieve an increased change in magnitude. Our technique, that is, the fulcrum bending position, may offer an alternative method in the detection or exclusion of pathological mobility in patients with spondylolisthesis.

Motion Analysis in Lumbar Spinal Stenosis With Degenerative Spondylolisthesis: A Feasibility Study of the 3DCT Technique Comparing Laminectomy Versus Bilateral Laminotomy

STUDY DESIGN

This was a randomized radiologic biomechanical pilot study in vivo.

OBJECTIVE

The objectives of this study was to evaluate if 3-dimensional computed tomography is a feasible tool in motion analyses of the lumbar spine and to study if preservation of segmental midline structures offers less postoperative instability compared with central decompression in patients with lumbar spinal stenosis with degenerative spondylolisthesis.

SUMMARY OF BACKGROUND DATA

The role of segmental instability after decompression is controversial. Validated techniques for biomechanical evaluation of segmental motion in human live subjects are lacking.

METHODS

In total, 23 patients (mean age, 68 y) with typical symptoms and magnetic resonance imaging findings of spinal stenosis with degenerative spondylolisthesis (>3 mm) in 1 or 2 adjacent lumbar levels from L3 to L5 were included. They were randomized to either laminectomy (LE) or bilateral laminotomy (LT) (preservation of the midline structures). Documentation of segmental motion was made preoperatively and 6 months postoperatively with CT in provoked flexion and extension. Analyses of movements were performed with validated software. The accuracy for this method is 0.6 mm in translation and 1 degree in rotation. Patient-reported outcome measures were collected from the Swespine register preoperatively and 2-year postoperatively.

RESULTS

The mean preoperative values for 3D rotation and translation were 6.2 degrees and 1.8 mm. The mean increase in 3D rotation 6 months after surgery was 0.25 degrees after LT and 0.7 degrees after LE (P=0.79) while the mean increase in 3D translation was 0.15 mm after LT and 1.1 mm after LE (P=0.42). Both surgeries demonstrated significant improvement in patient-reported outcome measures 2 years postoperatively.

CONCLUSIONS

The 3D computed tomography technique proved to be a feasible tool in the evaluation of segmental motion in this group of older patients. There was negligible increase in segmental motion after decompressive surgery. LE with removal of the midline structures did not create a greater instability compared with when these structures were preserved.

Utility of Supine Lateral Radiographs for Assessment of Lumbar Segmental Instability in Degenerative Lumbar Spondylolisthesis

STUDY DESIGN

Retrospective chart review OBJECTIVE.: To determine whether supine lateral radiographs increase the amount of segmental instability visualized in single-level lumbar degenerative spondylolisthesis, when compared to traditional lateral flexion-extension radiographs. We hypothesized that supine radiographs increase the amount of segmental instability seen in single-level lumbar spondylolisthesis when compared to flexion-extension.

SUMMARY OF BACKGROUND DATA

Accurate evaluation of segmental instability is critical to the management of lumbar spondylolisthesis. Standing flexion-extension lateral radiographs are routinely obtained, as it is believed to precipitate the forward-backward motion of the segment; however, recent studies with magnetic resonance imaging and computed tomography have shown that the relaxed supine position can facilitate the reduction of the anterolisthesed segment. Here, we show that inclusion of supine lateral radiographs increases the amount of segmental instability seen in single-level lumbar spondylolisthesis when compared to traditional lateral radiographs.

METHODS

Supine lateral radiographs were added to the routine evaluation (standing neutral/flexion/extension lateral radiographs) of symptomatic degenerative spondylolisthesis at our institution. In this retrospective study, 59 patients were included. The amount of listhesis was measured and compared on each radiograph: standing neutral lateral ("neutral"), standing flexion lateral ("flexion"), standing extension lateral ("extension"), and supine lateral ("supine").

RESULTS

A total of 59 patients (51 women, 8 men), with a mean age of 63.0 years (±9.85 yr) were included. The mean mobility seen with flexion-extension was 5.53 ± 4.11. The mean mobility seen with flexion-supine was 7.83% ± 4.67%. This difference was significant in paired t test (P = 0.00133), and independent of age and body mass index. Maximal mobility was seen between flexion and supine radiographs in 37 patients, between neutral and supine radiographs in 11 cases, and between traditional flexion-extension studies in 11 cases.

CONCLUSION

Supine radiograph demonstrates more reduction in anterolisthesis than the extension radiograph. Incorporation of a supine lateral radiograph in place of extension radiograph can improve our understanding of segmental mobility when evaluating degenerative spondylolisthesis.

LEVEL OF EVIDENCE

3.

Lumbar degenerative spondylolisthesis epidemiology: A systematic review with a focus on gender-specific and age-specific prevalence

The epidemiology of lumbar degenerative spondylolisthesis (DS) remains controversial. We performed a systematic review with the aim of gaining a better understanding of the prevalence of DS in the general population. The results showed that the prevalence of DS is very gender- and age-specific. Few women and men develop DS before they are 50 years old. After 50 years of age, both women and men begin to develop DS, with women having a faster rate of development than men. For elderly Chinese (≥ 65 years, mean age: 72.5 years), large population-based studies MsOS (Hong Kong, females: n = 2000) and MrOS (Hong Kong, males: n = 2000) showed DS prevalence was 25.0% in women and 19.1% in men. The female:male (F:M) prevalence ratio was 1.3:1. The published data for MsOS (USA) and MrOS (USA) studies seem to show that elderly Caucasian Americans have a higher DS prevalence, being approximately 60-70% higher than elderly Chinese; however, the F:M prevalence ratio was similar to the elderly Chinese population. Patient data showed that female patients more often received surgical treatment than male and preliminary data showed the ratio of female to male patients receiving surgical treatment did not differ between Northeast Asians (Chinese, Japanese, and Korean), Europeans, and American Caucasians, being around 2:1 in the elderly population. The existing data also suggest that menopause may be a contributing factor for the accelerated development of DS in postmenopausal women. The translational potential of this article: A better understanding of epidemiology of lumbar degenerative spondylolisthesis can support patient consultation and treatment planning.

Interobserver reproducibility of radiographic evaluation of lumbar spine instability

OBJECTIVE:

To measure the interobserver reproducibility of the radiographic evaluation of lumbar spine instability.

METHODS:

Measurements of the dynamic radiographs of the lumbar spine in lateral view were performed, evaluating the anterior translation and the angulation among the vertebral bodies. The tests were evaluated at workstations of the organization, through the Carestream Health Vue RIS (PACS), version 11.0.12.14 Inc. 2009© system.

RESULTS:

Agreement in detecting cases of radiographic instability among the observers varied from 88.1 to 94.4%, and the agreement coefficients AC1 were all above 0.8, indicating excellent agreement.

CONCLUSION:

The interobserver analysis performed among orthopedic surgeons with different levels of training in dynamic radiographs of the spine obtained high reproducibility and agreement. However, some factors, such as the manual method of measurement and the presence of vertebral osteophytes, might have generated a few less accurate results in this comparative evaluation of measurements.

OBJETIVO:

Mensurar a reprodutibilidade interobservadores da avaliação radiográfica da instabilidade da coluna lombar.

MÉTODOS:

Foram realizadas mensurações das radiografias dinâmicas de coluna lombar na incidência em perfil, avaliando-se a translação anterior e a angulação entre os corpos vertebrais. Os exames foram avaliados em workstations da própria instituição, por meio do sistema Vue RIS (PACS) da Carestream Health, versão 11.0.12.14 Inc. 2009©.

RESULTADOS:

A proporção de concordância em detecção de casos de instabilidade radiográfica entre os observadores variou de 88,1 a 94,4%, e os coeficientes de concordância AC1 estiveram todos acima de 0,8, indicando concordância excelente.

CONCLUSÃO:

A análise interobservadores realizada entre médicos ortopedistas com diferentes níveis de treinamento em radiografias dinâmicas da coluna vertebral obteve elevada reprodutibilidade e concordância. No entanto, alguns fatores, como método manual de aferição e a presença de osteófitos vertebrais, podem ter gerado alguns resultados menos consistentes nessa avaliação comparativa de medidas.

A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis

BACKGROUND

The efficacy of fusion surgery in addition to decompression surgery in patients who have lumbar spinal stenosis, with or without degenerative spondylolisthesis, has not been substantiated in controlled trials.

METHODS

We randomly assigned 247 patients between 50 and 80 years of age who had lumbar spinal stenosis at one or two adjacent vertebral levels to undergo either decompression surgery plus fusion surgery (fusion group) or decompression surgery alone (decompression-alone group). Randomization was stratified according to the presence of preoperative degenerative spondylolisthesis (in 135 patients) or its absence. Outcomes were assessed with the use of patient-reported outcome measures, a 6-minute walk test, and a health economic evaluation. The primary outcome was the score on the Oswestry Disability Index (ODI; which ranges from 0 to 100, with higher scores indicating more severe disability) 2 years after surgery. The primary analysis, which was a per-protocol analysis, did not include the 14 patients who did not receive the assigned treatment and the 5 who were lost to follow-up.

RESULTS

There was no significant difference between the groups in the mean score on the ODI at 2 years (27 in the fusion group and 24 in the decompression-alone group, P=0.24) or in the results of the 6-minute walk test (397 m in the fusion group and 405 m in the decompression-alone group, P=0.72). Results were similar between patients with and those without spondylolisthesis. Among the patients who had 5 years of follow-up and were eligible for inclusion in the 5-year analysis, there were no significant differences between the groups in clinical outcomes at 5 years. The mean length of hospitalization was 7.4 days in the fusion group and 4.1 days in the decompression-alone group (P<0.001). Operating time was longer, the amount of bleeding was greater, and surgical costs were higher in the fusion group than in the decompression-alone group. During a mean follow-up of 6.5 years, additional lumbar spine surgery was performed in 22% of the patients in the fusion group and in 21% of those in the decompression-alone group.

CONCLUSIONS

Among patients with lumbar spinal stenosis, with or without degenerative spondylolisthesis, decompression surgery plus fusion surgery did not result in better clinical outcomes at 2 years and 5 years than did decompression surgery alone. (Funded by an Uppsala institutional Avtal om Läkarutbildning och Forskning [Agreement concerning Cooperation on Medical Education and Research] and others; Swedish Spinal Stenosis Study ClinicalTrials.gov number, NCT01994512.).

Guideline summary review: An evidence-based clinical guideline for the diagnosis and treatment of degenerative lumbar spondylolisthesis

BACKGROUND CONTEXT

The North American Spine Society's (NASS) Evidence-Based Clinical Guideline for the Diagnosis and Treatment of Degenerative Lumbar Spondylolisthesis features evidence-based recommendations for diagnosing and treating degenerative lumbar spondylolisthesis. The guideline updates the 2008 guideline on this topic and is intended to reflect contemporary treatment concepts for symptomatic degenerative lumbar spondylolisthesis as reflected in the highest quality clinical literature available on this subject as of May 2013. The NASS guideline on this topic is the only guideline on degenerative lumbar spondylolisthesis included in the Agency for Healthcare Research and Quality's National Guideline Clearinghouse (NGC).

PURPOSE

The purpose of this guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for patients with degenerative lumbar spondylolisthesis. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition.

STUDY DESIGN

A systematic review of clinical studies relevant to degenerative spondylolisthesis was carried out.

METHODS

This NASS spondyolisthesis guideline is the product of the Degenerative Lumbar Spondylolisthesis Work Group of NASS' Evidence-Based Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members used the NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guidelines were submitted to an internal peer review process and ultimately approved by the NASS Board of Directors. Upon publication, the Degenerative Lumbar Spondylolisthesis guideline was accepted into the NGC and will be updated approximately every 5 years.

RESULTS

Twenty-seven clinical questions were addressed in this guideline update, including 15 clinical questions from the original guideline and 12 new clinical questions. The respective recommendations were graded by strength of the supporting literature, which was stratified by levels of evidence. Twenty-one new or updated recommendations or consensus statements were issued and 13 recommendations or consensus statements were maintained from the original guideline.

CONCLUSIONS

The clinical guideline was created using the techniques of evidence-based medicine and best available evidence to aid practitioners in the care of patients with degenerative lumbar spondylolisthesis. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flow chart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/Pages/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx and will remain updated on a timely schedule.

Utility of Flexion-Extension Radiographs in Lumbar Spondylolisthesis: A Prospective Study

STUDY DESIGN

Prospective cohort study in consecutive patients.

OBJECTIVE

To investigate and compare the use of 2 diagnostic modalities in the evaluation of stability in lumbar spondylolisthesis.

SUMMARY OF BACKGROUND DATA

Evaluating potential instability in lumbar spondylolisthesis is significant to its management. Lateral lumbar flexion-extension (FE) radiograph is frequently obtained on the basis of a thought that this forward-backward movement can actually describe hypermobility at the listhetic segment. However, simply comparing standard upright lumbar lateral radiograph (U) with a supine sagittal magnetic resonance image (S) (combined, US), something typically conducted for patients with lumbar spondylolisthesis, may also be used.

METHODS

This prospective study included a cohort of 68 consecutive patients with lumbar spondylolisthesis seen in the outpatient clinic of a single hospital. The mobility observed in US was compared with that observed in FE. The ability to identify "instability" using US was compared with that using FE. In addition, the relationships between mobility determined using FE or US and sex, age, height, weight, body mass index, primary symptom (with or without back pain), nature of spondylolisthesis (degenerative or isthmic), listhetic segment, slippage grade, and focal disc height were examined.

RESULTS

Overall, the mobility in US was significantly higher than that in FE (7.68 ± 5.34% vs. 4.90 ± 3.82%, t =-3.545, P = 0.001). The ability to identify "instability" on the basis of US was improved compared with that obtained using FE. Female patients demonstrated higher mobility in FE than male patients to a significant degree. Back pain, isthmic spondylolisthesis, and slippage grade also showed some relevance with mobility but without statistical significance.

CONCLUSION

US may offer an easily available, alternative diagnostic modality in lumbar spondylolisthesis, with the potential of reducing both radiation exposure and costs. Further studies should focus on its influence in clinical decision making.

LEVEL OF EVIDENCE

2.

Functional radiography in examination of spondylolisthesis

OBJECTIVE

Despite the predominant use of standing flexion-extension radiography for quantifying instability in isthmic and degenerative spondylolisthesis, other functional radio-graphic techniques have been presented in the literature.

CONCLUSION

The current evidence reported in the literature is insufficient to influence how the results of these other functional radiographic techniques should affect clinical management; however, it does raise doubts regarding the accuracy and reliability of standing flexion-extension radiography in this setting. Based on the currently available evidence and until randomized studies are performed to assess the efficacy of functional radiographic techniques in directing clinical decision making, positioning schemes other than traditional standing flexion-extension may be considered as options in the evaluation of patients with symptomatic isthmic and degenerative spondylolisthesis in which standard flexion-extension radiographs fail to show pathologic instability.

Hidden spondylolisthesis: unrecognized cause of low back pain? Prospective study about the use of dynamic projections in standing and recumbent position for the individuation of lumbar instability

INTRODUCTION

Dynamic X-rays (DXR) are widely recognized as an effective method to detect lumbar instability (LI). They are usually performed with the patient in standing position (SDXR). In our opinion, standing position inhibits micromovements of the lumbar segment interested by the listhesis, thanks to paravertebral muscles antalgic contraction and augmented tone. We aim to demonstrate that DXR in recumbent position (RDXR), reducing the action of paravertebral muscles, can discover hypermovements not evidenced in SDXR.

METHODS

Between January 2011 and January 2013, we studied 200 consecutive patients with lumbar degenerative disease with MRI, SDXR, and RDXR. We aimed to find a correlation between low back or radicular pain and the presence of a spondylolisthesis not showed by the SDXR, but showed by the RDXR.

RESULTS

We analysed 200 patients: of the 133 not pathologic in SDXR, 43 patients (32.3 %) showed an hypermovement in RDXR (p = 0.0001) without any significant correlation between hidden listhesis and age, sex, or level involved.

CONCLUSIONS

The aim of our study is to determine whether in patients with lumbalgy without evidence of listhesis in SDXR, pain can be attributed to a faccettal syndrome or to a spondylolisthesis. Consequence of pain is augmented muscular tone of the paravertebral musculature, particularly in standing position. Augmented muscular tone tries to inhibit the pain generator, attempting to limit the slippage of the involved segment. In patients examined in RDXR, the tone of paravertebral musculature is reduced, showing the hidden spondylolisthesis.

Radiographic evaluation of ventral instability in lumbar spondylolisthesis: do we need extension radiographs in routine exams?

PURPOSE

To determine the usefulness of acquiring extension radiographs for the evaluation of the degree of spondylolisthesis.

METHODS

Routine radiographs of the lumbar spine were retrospectively evaluated in 87 patients (mean-age 63, range 32-86) by two independent radiologists. All patients received radiographs in standing neutral, flexion and extension position. Vertebral body depth, sagittal translational displacement and lordosis angle were measured and slip percentage (SP) was calculated on standing neutral, flexion and extension radiographs. Statistical analysis was performed with a two-sided t test. Inter- and intraobserver reliability was assessed using the kappa-coefficient.

RESULTS

There was no statistically significant SP-difference between neutral standing and extension images. Ventral instability was diagnosed in 25-34 % (cut-off >8 % SP-difference) for neutral versus flexion comparison. The detection rate of flexion-extension radiographs representing the extremes of motion was lower with 15-22 %. Inter- and intraobserver reliability was good to excellent.

CONCLUSION

Slip percentage in routine standing extension radiography ultimately does not differ from that obtained in a static neutral standing view. Extension radiography may therefore be omitted in a routine work-up of ventral instability in lumbar spondylolisthesis.