Functional radiography in examination of spondylolisthesis

Reference Data for Diagnosis of Spondylolisthesis and Disc Space Narrowing Based on NHANES-II X-rays

Robust reference data, representing a large and diverse population, are needed to objectively classify measurements of spondylolisthesis and disc space narrowing as normal or abnormal. The reference data should be open access to drive standardization across technology developers. The large collection of radiographs from the 2nd National Health and Nutrition Examination Survey was used to establish reference data. A pipeline of neural networks and coded logic was used to place landmarks on the corners of all vertebrae, and these landmarks were used to calculate multiple disc space metrics. Descriptive statistics for nine SPO and disc metrics were tabulated and used to identify normal discs, and data for only the normal discs were used to arrive at reference data. A spondylolisthesis index was developed that accounts for important variables. These reference data facilitate simplified and standardized reporting of multiple intervertebral disc metrics.

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.

Pain Control Affects the Radiographic Diagnosis of Segmental Instability in Patients with Degenerative Lumbar Spondylolisthesis

BACKGROUND

Diagnosing intervertebral instability is crucial for the treatment of degenerative lumbar spondylolisthesis (DLS). Disabling back pain will reduce spinal mobility which leads to an underestimate of the incidence of intervertebral instability. We hypothesized that adequate analgesia could alter the flexion/extension exam performance, and thus increase the diagnostic accuracy of segmental instability.

MATERIALS AND METHODS

One hundred patients with low-grade DLS were prospectively enrolled in the before-after cohort study. Standing lateral flexion/extension radiographs of lumbar spines were examined and analyzed before and after intramuscular injections of 30 mg ketorolac.

RESULTS

Pain score decreased significantly after analgesic injections (p < 0.001). Dynamic slip (DS), dynamic segmental angle (DA), dynamic lumbar lordosis, and slip percentage (SP) were significantly increased after pain reduction (all p < 0.001). According to the diagnostic criteria for segmental instability (DS > 4.5 mm, DA > 15°, or SP > 15%), there were 4%, 4%, and 0.7% of total motion segments fulfilling the criteria which markedly increased to 42%, 32%, and 16.7% after analgesia was administered. The incidence of instability also increased from 6% to 38% after analgesia.

CONCLUSIONS

The diagnosis rate of intervertebral instability is commonly underestimated in the presence of low back pain. This short-term pain relief facilitates reliable functional imaging adding to the diagnosis of intervertebral instability.

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.

Assessing the Differences in Measurement of Degree of Spondylolisthesis Between Supine MRI and Erect X-Ray: An Institutional Analysis of 255 Cases

BACKGROUND

Degenerative spondylolisthesis is the displacement of one vertebral body over the adjacent one. While standing and flexion-extension X-rays are preferred for determining listhesis, magnetic resonance imaging (MRI) is often utilized to assess the compression of nerve root or spinal cord.

OBJECTIVE

To investigate the difference in radiographic measurements of spondylolisthesis between X-rays and MRI.

METHODS

We retrospectively reviewed the records and radiographic images of patients with a confirmed diagnosis of spondylolisthesis undergoing operation in 2016. Primary variable of interest was the degree of slippage as per the Meyerding method. Agreement between the 2 reviewers was assessed using the 2-way intraclass correlation coefficient (ICC) for slippage percentage and Cohen's Kappa for grade. Agreement of Meyerding grade between the 2 imaging techniques was assessed using Cohen's Kappa, while the slip percentage measured for each technique was compared using a Bland-Altman (BA) plot, mean difference (MD), and 1-way ICC.

RESULTS

A total of 255 cases were analyzed. ICC between the 2 reviewers was found to be 0.75 (95% confidence interval [CI] = 0.64-0.83, P < .001) for X-ray and 0.76 (95% CI = 0.66-0.83, P < .001) for MRI. Agreement between X-ray and MRI for grading of spondylolisthesis was found to be poor (kappa = 0.32, P < .001). BA plot between X-ray and MRI measurements revealed an MD of 4.4% (95% limits of agreement: -10.3% to 19.3%) with 5.16% observations outside the limits of agreement and 1-way ICC of 0.35 showing poor agreement.

CONCLUSION

Our results demonstrate the discrepancy of spondylolisthesis grade measurements between weight-bearing X-ray and nonweight-bearing MRI. Careful evaluation of both imaging technique is warranted to determine the final severity of pathology and tailoring of management plan.

Overreporting of the disc herniation in lumbar spine MRI scans performed for patients with spondylolisthesis

BACKGROUND

Spondylolisthesis is often misdiagnosed on magnetic resonance imaging (MRI) as the slip may reduce to a normal alignment when the patient lies supine. Often, disc herniation is reported at the level of spondylolisthesis.

PURPOSE

To determine the incidence rates of disc herniation at the level of spondylolisthesis.

MATERIAL AND METHODS

This is a retrospective study included 258 consecutive patients with spondylolisthesis who had lumbar spine MRI. The archived reports were collectively put in Group 1. A musculoskeletal radiologist and a spine surgeon reviewed the imaging studies together. Their readings were referred to as Group 2. The findings of both groups were compared to evaluate whether disc herniation was overreported.

RESULTS

Group 1 reported findings of true disc herniation in 112 (41.6%) cases and pseudo disc herniation or no findings of disc herniation at the level of spondylolisthesis in 157 (58.4%) cases. Group 2 reported findings of a true disc herniation in 25 (9.3%) cases and pseudo disc herniation or no findings of disc herniation in the remaining 244 (90.7%) cases. There was a statistically significant difference in the reporting rates between these two groups (P < 0.02). The most overreported finding was the disc bulging (P < 0.01).

CONCLUSION

The current study showed overreporting of disc herniation in lumbar spine MRI scans performed for patients with established spondylolisthesis. The majority of disc pathology at the level of spondylolisthesis are pseudo disc rather than a true disc herniation. An accurate diagnosis is vital in planning surgical intervention.

Real-time dynamic 3-T MRI assessment of spine kinematics: a feasibility study utilizing three different fast pulse sequences

BACKGROUND

Half-Fourier acquisition single-shot turbo spin-echo (HASTE), continuous radial gradient-echo (GRE), and True FISP allow real-time dynamic assessment of the spine.

PURPOSE

To evaluate the feasibility of adding dynamic sequences to routine spine magnetic resonance imaging (MRI) for assessment of spondylolisthesis.

MATERIAL AND METHODS

Retrospective review was performed of patients referred for dynamic MRI of the cervical or lumbar spine between January 2017 and 2018 who had flexion-extension radiographs within two months of MRI. Exclusion criteria were: incomplete imaging; spinal hardware; and inability to tolerate dynamic examination. Blinded, independent review by two board-certified musculoskeletal radiologists was performed to assess for spondylolisthesis (>3 mm translation); consensus review of dynamic radiographs served as the gold standard. Cervical spinal cord effacement was assessed. Inter-reader agreement and radiographic concordance was calculated for each sequence.

RESULTS

Twenty-one patients were included (8 men, 13 women; mean age 47.9 ± 16.5 years). Five had MRI of the cervical spine and 16 had MRI of the lumbar spine. Mean acquisition time was 18.4 ± 1.7 min with dynamic sequences in the range of 58-77 s. HASTE and True FISP had the highest inter-reader reproducibility (κ = 0.88). Reproducibility was better for the lumbar spine (κ = 0.94) than the cervical spine (κ = 0.28). Sensitivity of sequences for spondylolisthesis was in the range of 68.8%-78.6%. All three sequences had high accuracy levels: ≥90.5% averaged across the cervical and lumbar spine. Cervical cord effacement was observed during dynamic MRI in two cases (100% agreement).

CONCLUSION

Real-time dynamic MRI sequences added to spine MRI protocols provide reliable and accurate assessment of cervical and lumbar spine spondylolisthesis during flexion and extension.

Surgical Outcome of Decompression and Fixation of Degenerative Lumbosacral Spondylolisthesis Surgery in Pakistani Population

Background

Spondylolisthesis is characterized by the slipping of one vertebra, compared with the underlying one, due to structural and degenerative changes. Its origin is multifactorial which includes disc degeneration, facet joint anatomic orientation, iliolumbar configuration, and ligament hyperlaxity. The most common operative treatment is decompression and may require an individualized surgical plan. However, only decompression may progress the slippage which can result in pain or recurrence of neurological complaints. Therefore, lumbar fusion and fixation are considered appropriate to stabilise the spine and prevent delayed deterioration. The aim of our study was to find out the outcome of posterior decompression, with reduction and fixation of lumbosacral spondylolisthesis by Oswestry Disability Index (ODI) to improve further our results.

Methods

This study was conducted from July 2013 to February 2017 including 94 patients with lumbosacral spondylolisthesis. The Meyerding classification was used to grade the extent of vertebral slippage. The assessment was done using the ODI.

Results

There were 50 (53.19%) males and 54 (46.80%) females with a mean age of 44 years ± 10.49 SD. Backache was present in all patients and claudication in 85 (90.42%) patients. There were 10 (10.63%) patients with spondylolisthesis at L3-L4, 36 (38.29%) at L5-S1 and 48 patients (51.06%) at L4-L5 level. In 48 patients with L4-L5 level, 38 (79.16%) were in grade II while six (12.5%) were in grade III. According to the preoperative ODI score, 38 patients were placed in moderate disability, 42 patients were severely disabled while four patients were disabled.

Good outcome was achieved in a total of 79 (84.04%) patients. In 40 (42.55%) patients, with complete reduction, the good outcome achieved in 35 (83.33%) while in 22 (23.40%) patients there was no reduction and a good outcome was achieved in 17 (77.27%) patients. In 38 (40.42%) patients with moderate disability, 32 (84.04%) patients had a good outcome. Post-operative cerebrospinal fluid (CSF) leak occurred in five (5.31%) and wound infection in seven (7.44%) patients while there was no mortality.

Conclusion

Reduction with decompression can have a good outcome in spondylolisthesis, and ODI should be used as a predictor of outcome. It also shows that proper decompression is required and not a complete reduction.

Radiologic Evaluation Of Lumbar Spinal Stenosis: The Integration Of Sagittal And Axial Views In Decision Making For Minimally Invasive Surgical Procedures

Radiologic findings in combination with clinical symptoms are critical in the diagnosis and evaluation of the severity of lumbar spinal stenosis (LSS) as well as the need for surgical treatment. Dynamic radiographs, computerized tomography (CT), and magnetic resonance imaging (MRI) each provide different but interrelated pieces of information in the patient with lumbar spinal stenosis. Making a treatment decision based only on one of the radiographic studies may negatively affect the treatment outcome. Minimal procedures are predicated on identifying and performing surgery on a limited segment of the lumbar spinal canal affected by the stenosis compared to what occurs during open surgery where the judgment of the spine surgeon often expanded the decompression area based on real-time intra-operative findings correlated with radiologic findings of stenosis. As newer, less invasive procedures are gaining acceptance for surgical treatment of spinal stenosis with symptomatic claudication, radiologic studies become more critical in selecting the correct procedure since there may be no or minimal surgical visual confirmation of the pathology. This article will review how the finding of spinal deformity and motion, canal dimensions, viewed in multiple planes and the presence of facet fluid impact treatment decisions. Differences in these abnormal radiologic findings can affect the selection of surgical procedures ranging from open decompression with pedicle fixation, decompression with interlaminar stabilization, minimally invasive lumbar decompression, and percutaneous interspinous implants providing distraction without decompression. With the development of less invasive procedures, lumbar spinal stenosis is being evaluated and treated not only by spine surgeons but also by interventional pain and neuroradiology physicians that may not be totally familiar with the complexity of the pathology and neuro-radiology of LSS. Each radiologic study provides different information. The goal of this report is to provide a framework for the use of studies such as plain X-rays, dynamic films, MRI, and CT scans as well as the importance of different views, and how to use them in evaluating the abnormal radiologic anatomy seen with LSS and in selecting the most appropriate procedure.

Importance of Radiological Evaluation of Global Spinal Balance Together with Lower Limb Alignment in Planning Lumbar Spine Deformity Surgery - Illustrative Case Presentation

Background

The presented case illustrates the critical role of a detailed preoperative radiological evaluation in complex spine surgery.

Case Report

A 49-year-old patient was admitted for a revision surgery after L3–L5 fusion. Preoperative assessment showed preserved sagittal balance, coronal imbalance and valgus knee deformity. The patient reported pain of 8–10 in VAS (Visual Analogue Scale) and had an ODI (Oswestry Disability Index) of 60%. The first step of the surgery was L2–S1 fusion with decompression and spine deformity correction. The second step involved anti-valgus osteotomy of the right tibial bone.

Conclusions

The assessment of global spinal balance together with lower extremity alignment should be strongly recommended.

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.