Current Evidence Regarding Diagnostic Imaging Methods for Pediatric Lumbar Spondylolysis: A Report From the Scoliosis Research Society Evidence-Based Medicine Committee

Advances in Imaging (Intraop Cone-Beam Computed Tomography, Synthetic Computed Tomography, Bone Scan, Low-Dose Protocols)

Spine surgery has seen a rapid advance in the refinement and development of 3-dimensional and nuclear imaging modalities in recent years. Cone-beam CT has proven to be a valuable tool for improving the accuracy of pedicle screw placement. The use of synthetic CT and low-dose CT have also emerged as modalities which allow for little to no radiation while streamlining imaging workflows. Bone scans also serve to provide functional information about bone metabolism in both the preoperative and postoperative monitoring phases.

Management of low back pain accompanying sagittal plane pathologies in children: Spondylolysis/spondylolisthesis and Scheuermann's disease

Background

Low back pain in childhood was underappreciated for a long time, but recent studies report higher prevalences, up to 70%. Two of the common causes are spondylolyis/spondylolisthesis and Scheuermann's disease. These disorders are relevant in a way they both cause significant back pain, and may disrupt the sagittal spinal balance.

Purpose

To present the current evidence on the diagnosis, natural history and treatment of these disorders with a special focus on sagittal spinal alignment.

Methods

This study is conducted as a literature review.

Results and Conclusions

Spondylolysis and low-grade spondylolisthesis have a benign course and are typically treated conservatively. When pars repair is indicated, pedicle screw-based techniques achieve more than 90% fusion with acceptable complication rates. High-grade spondylolisthesis, however, is frequently progressive. Surgical treatment involves fusion, which can be done in situ or after reduction. Reduction is useful for "unbalanced" patients to acquire sagittal spinopelvic balance, and it is important to distinguish these patients. Despite lowering the risk for pseudoarthrosis, reduction brings a risk for neurologic complications. With re-operation rates as high as 40%, these patients definitely require careful preoperative planning. Scheuermann's disease generally causes back pain in addition to cosmetic discomfort during adolescence. If the kyphosis is lower than 60°, symptoms typically resolve into adulthood with conservative measures only. However, it must be kept in mind that these patients may experience problems with physical performance and have a lower quality of life even when the problem seems to have "resolved". Severe kyphosis and intractable back pain are the most frequently referred surgical indications, and surgery typically involves fusion. Proper utilization of osteotomies and proper selection of the upper and lower fusion levels are of utmost importance to prevent complications in these patients.

Predictors of Spondylolysis on Magnetic Resonance Imaging in Adolescent Athletes With Low Back Pain

Background:

Spondylolysis and undiagnosed mechanical low back pain (UMLBP) are the main causes of low back pain (LBP) in adolescent athletes. No studies have evaluated the difference in clinical and radiographic factors between these 2 conditions. Furthermore, it remains unclear which adolescent athletes with LBP should undergo advanced imaging examination for spondylolysis.

Purpose:

To compare the clinical and radiographic factors of adolescent athletes with spondylolysis and UMLBP who did not have neurological symptoms or findings before magnetic resonance imaging (MRI) evaluation and to determine the predictors of spondylolysis findings on MRI.

Study Design:

Cohort study, Level of evidence, 3.

Methods:

The study population included 122 adolescent athletes aged 11 to 18 years who had LBP without neurological symptoms or findings and who underwent MRI. Of these participants, 75 were ultimately diagnosed with spondylolysis, and 47 were diagnosed with UMLBP. Clinical factors and the following radiographic parameters were compared between the 2 groups: spina bifida occulta, lumbar lordosis (LL) angle, and the ratio of the interfacet distance of L1 to that of L5 (L1:L5 ratio, %). A logistic regression analysis was performed to evaluate independent predictors of spondylolysis on MRI scans.

Results:

Significantly more athletes with spondylolysis were male (82.7% vs 48.9%; P < .001), had a greater LL angle (22.8° ± 8.1° vs 19.3° ± 8.5°; P = .02), and had a higher L1:L5 ratio (67.4% ± 6.3% vs 63.4% ± 6.6%; P = .001) versus athletes with UMLBP. A multivariate analysis revealed that male sex (odds ratio [OR], 4.66; P < .001) and an L1:L5 ratio of >65% (OR, 3.48; P = .003) were independent predictors of positive findings of spondylolysis on MRI scans.

Conclusion:

The study findings indicated that sex and the L1:L5 ratio are important indicators for whether to perform MRI as an advanced imaging examination for adolescent athletes with LBP who have no neurological symptoms and findings.

Diagnostic accuracy of MRI for identifying posterior element bone stress injury in athletes with low back pain: a systematic review and narrative synthesis

Objective

To investigate the diagnostic accuracy of MRI for identifying posterior element bone stress injury (PEBSI) in the athletic population with low back pain (LBP).

Study Design

A systematic review searched for published sources up until July 2020. Eligibility criteria: prospective cohort design, MRI diagnosis, adolescents/young adults, chief symptoms of LBP, PEBSI as the clinical diagnosis and SPECT-CT as reference standard. Risk of bias and overall quality were assessed using QUADAS-2 and GRADE, respectively. A narrative synthesis was conducted.

Results

Four studies were included, with three included in the quantitative synthesis. Compared with SPECT-CT, two studies involving MRI demonstrated sensitivity and specificity of 80% and 100%, and 88% and 97%, respectively. Compared with CT, one study involving MRI demonstrated sensitivity and specificity of 97% and 91%, respectively. Risk of bias was moderate to high although consistency across studies was noted.

Conclusion

Findings support further research to consider MRI as the modality of choice for diagnosing PEBSI. MRI was consistent with SPECT-CT for ruling-in PEBSI, but the clinical value of cases where MRI had false negatives remains uncertain due to possible over-sensitivity by SPECT-CT.

PROSPERO registration number

CRD42015023979.

[Radiological diagnostics of lumbar spine fractures]

BACKGROUND

The lumbar spine forms the lowermost part of the mobile spinal column. Due to anatomical properties, the lumbar spine is highly flexible in the sagittal directions, thus, rendering it susceptible to both flexion and extension forces with the thoracolumbar junction being the most vulnerable part of it. To date, the modern thoracolumbar spine fracture classification is given by the AOSpine classification system based on the well-known Magerl classification of vertebral fracture morphology but now includes both neurological criteria and clinical modifiers, such as ankylosing spondylitis.

DIAGNOSTICS

Whereas plain radiography remains a mainstay in the diagnostic evaluation of low-energy trauma patients, computed tomography (CT) exhibits its unsurpassed power in polytrauma and plays a decisive role in all equivocal cases where the osseous situation is unclear. However, magnetic resonance imaging (MRI) is increasingly gaining importance for assessing both discoligamentous integrity and intraspinal condition. Both CT and MRI have direct input in classifying fractures according to the AOSpine classification.

RESULTS

Regarding fracture morphology, three main types (A-C) based on the stability are distinguished. C‑type spinal injuries are all considered unstable, irrespective of type and severity of vertebral malalignment. Injuries to the anterior and posterior ligamentous complex are also considered to interfere with stability (B-type injuries).

CONCLUSIONS

Special fracture patterns of the injured ankylosed and osteoporotic spine as well as of the pediatric lumbar spine are discussed. A survey is also given about several differential diagnoses (malignant fractures, anomalies, normal variants).

Is the Scotty Dog Sign Adequate for Diagnosis of Fractures in Pediatric Patients with Lumbar Spondylolysis?

Introduction

Recent advances in diagnostic imaging, such as computed tomography (CT) and magnetic resonance imaging (MRI), have allowed early diagnosis of lumbar spondylolysis (LS). However, few outpatient clinics are equipped with such imaging apparatuses and must rely on plain radiographs for the diagnosis of LS. The aim of this retrospective study was to identify how accurately fracture lines can be detected on plain radiographs in patients with LS.

Methods

Patients with a diagnosis of LS were staged as early, progressive, or terminal. We evaluated whether fracture lines could be detected on plain radiographs and compared the detection rates under the following conditions: two directions including anteroposterior and lateral views (2 views), four directions including both oblique views (4 views), four directions including dynamic lateral views (4-D views), and all six directions (6 views).

Results

In early LS, the fracture line detection rate was 11.4% using 2 views, 20.5% using 4 views and 4-D views, and 22.7% using 6 views. In progressive LS, the fracture line detection rate was 54.2% using 2 views, 70.8% using 4-D views, 75.0% using 4 views, and 79.2% using 6 views. The respective detection rates for terminal LS were 85.0%, 100%, 100%, and 100%.

Conclusions

Although terminal LS was diagnosed accurately on plain radiographs in all patients, the detection rates were only 22.7% and 79.2% in patients with early and progressive LS, respectively. These results suggest that plain radiographic films can no longer be considered adequate for early and accurate diagnosis of LS. Advanced imaging procedures, such as MRI in the early diagnosis or CT for persistent cases, are recommended to obtain an accurate diagnosis of early stage LS in pediatric patients requiring conservative treatment to achieve bony healing.

Current Use of Evidence-Based Medicine in Pediatric Spine Surgery

Evidence-based medicine (EBM) is a process of decision-making aimed at making the best clinical decisions as they relate to patients' health. The current use of EBM in pediatric spine surgery is varied, based mainly on the availability of high-quality data. The use of EBM is limited in idiopathic scoliosis, whereas EBM has been used to investigate the treatment of pediatric spondylolysis. Studies on early onset scoliosis are of low quality, making EBM difficult in this condition. Future focus and commitment to study quality in pediatric spinal surgery will likely increase the role of EBM in these conditions.

The prevalence of lumbar spondylolysis in young children: a retrospective analysis using CT

PURPOSE

Although lumbar spondylolysis is encountered in general population with an incidence estimated to be 3-10%, limited information is available for children. The aim of the study is to determine the prevalence of spondylolysis according to associated vertebral bony malformation and spinopelvic parameters in children under eight requiring CT evaluation for unrelated lumbar conditions.

METHODS

Seven hundred and seventeen abdominal and pelvic multi-detector CT scans were obtained in patients under 8 years of age were reviewed. Two board certificated radiologists and two resident radiologists retrospectively evaluated CT scans for lumbar spondylolysis and associated malformations. Pelvic incidence and spondylolisthesis were reported.

RESULTS

Our analysis included 717 CT scans in 532 children (259 girls and 273 boys). Twenty-five cases of spondylolysis were diagnosed (16 bilateral and 9 unilateral, 64 and 36%, respectively) in 14 boys (56%) and 11 girls (44%), associating with 12 grade I spondylolisthesis. The mean normal pelvic incidence was 45° (median 44°, SD 7°). The prevalence of spondylolysis was 1% in children under age 3 (n = 3 among 292 patients), 3.7% in children under age 6 (n = 17 among 454 patients) and 4.7% among the 532 patients. Unilateral spondylolysis was significantly associated with a spinal malformation (p = 0.04, Fisher's exact test), with normal pelvic incidence. Half of the patients with bilateral spondylolysis had high pelvic incidence.

CONCLUSIONS

We observed a prevalence peak of unilateral spondylolysis in the context of a specific malformation in young infants under age 4 with normal pelvic incidence, and, then, a progressive increase in the prevalence of bilateral isolated spondylolysis.