Radiological findings and healing patterns of incomplete stress fractures of the pars interarticularis

Long-term CT follow-up of patients with lumbar spondylolysis reveals low rate of spontaneous bone fusion

OBJECTIVES

Knowledge about the long-term outcome of patients with lumbar spondylolysis (LS) is limited. This study assessed the frequency of bone fusion in conservatively treated lumbar spondylolysis with photon counting detector computed tomography.

METHODS

Patients with lumbar spondylolysis diagnosed with CT or MRI were prospectively enrolled and underwent CT 5-10 years after initial imaging. Image assessment included evaluation of Meyerding grade, listhesis size, measurement of the lysis gap, and disc integrity on the lysis level. Comparisons were made between bone fusion as the primary endpoint and sex, body mass index, age at diagnosis, follow-up interval, size of listhesis, Meyerding grade, size of the lysis gap, sports activity, and presence of pain.

RESULTS

A total of 39 patients (26.0 ± 3.1 years, 15 female) with lumbar spondylolysis on 41 levels were included after a mean follow-up period of 9.1 ± 2.2 years. Nine patients (22.0%, four female) showed complete fusion of the lysis gap. Patients with bone fusion of the lysis gap had a significantly lower Meyerding grade (p = 0.01), smaller size of the listhesis (p = 0.019), and smaller anterior and posterior lysis gap size (p = 0.046 and p = 0.011, respectively). Unilateral lyses showed significantly higher fusion rates than bilateral lyses (40.0% vs. 16.1%, p = 0.01). No statistically significant difference was found for pain at follow-up between patients with and without bone fusion (p = 0.253).

CONCLUSION

Bone fusion occurred in about a fifth of conservatively treated lumbar spondylolysis after a follow-up period of 9 years. Factors associated with a successful fusion were a lower Meyerding grade, minimal listhesis, and a small lysis gap.

T1-VIBE and STIR MRI of lumbar pars interarticularis injuries in elite athletes: fracture characterisation and potential prognostic indicators

OBJECTIVES

To assess how pars interarticularis fracture characteristics on T1-VIBE and STIR MRI relate to healing and identify anatomical parameters that may impact healing.

MATERIALS AND METHODS

A retrospective review of an MRI series of lumbar pars interarticularis injuries in elite athletes over a 3-year period. Fracture configurations, signal intensities and anatomical parameters were recorded by two radiologists. Statistical analysis employed multilevel mixed-effects linear regressions, adjusted for repeated measures and baseline covariates.

RESULTS

Forty-seven lumbar pars interarticularis injuries among 31 athletes were assessed. On final scans for each athlete, 15% (7/47) injuries had worsened, 23% (11/47) remained stable, 43% (20/47) partially healed and 19% (9/47) healed completely. Healing times varied, quickest was 49 days for a chronic fracture in a footballer. Bone marrow oedema signal was highest in worsened fractures, followed by improved, and lowest in stable fractures. As healing progressed, T1-VIBE signal at the fracture line decreased. Bone marrow oedema and fracture line signal peaked at 90-120 days before decreasing until 210-240 days. Fractures with smaller dimensions, more vertical orientation and a longer superior articular facet beneath were significantly associated with better healing (p < 0.05).

CONCLUSION

Most diagnosed athletic pars interarticularis injuries improve. Normalising T1-VIBE signal at the fracture line is a novel measurable indicator of bony healing. Contrastingly, bone marrow oedema signal is higher in active fractures irrespective of healing or deterioration. Injuries initially perceived as worsening may be exhibiting the normal osteoclastic phase of healing. Better outcomes favour smaller, vertical fractures with a longer superior articular facet beneath.

Deep-Learning-Aided Evaluation of Spondylolysis Imaged with Ultrashort Echo Time Magnetic Resonance Imaging

Isthmic spondylolysis results in fracture of pars interarticularis of the lumbar spine, found in as many as half of adolescent athletes with persistent low back pain. While computed tomography (CT) is the gold standard for the diagnosis of spondylolysis, the use of ionizing radiation near reproductive organs in young subjects is undesirable. While magnetic resonance imaging (MRI) is preferable, it has lowered sensitivity for detecting the condition. Recently, it has been shown that ultrashort echo time (UTE) MRI can provide markedly improved bone contrast compared to conventional MRI. To take UTE MRI further, we developed supervised deep learning tools to generate (1) CT-like images and (2) saliency maps of fracture probability from UTE MRI, using ex vivo preparation of cadaveric spines. We further compared quantitative metrics of the contrast-to-noise ratio (CNR), mean squared error (MSE), peak signal-to-noise ratio (PSNR), and structural similarity index (SSIM) between UTE MRI (inverted to make the appearance similar to CT) and CT and between CT-like images and CT. Qualitative results demonstrated the feasibility of successfully generating CT-like images from UTE MRI to provide easier interpretability for bone fractures thanks to improved image contrast and CNR. Quantitatively, the mean CNR of bone against defect-filled tissue was 35, 97, and 146 for UTE MRI, CT-like, and CT images, respectively, being significantly higher for CT-like than UTE MRI images. For the image similarity metrics using the CT image as the reference, CT-like images provided a significantly lower mean MSE (0.038 vs. 0.0528), higher mean PSNR (28.6 vs. 16.5), and higher SSIM (0.73 vs. 0.68) compared to UTE MRI images. Additionally, the saliency maps enabled quick detection of the location with probable pars fracture by providing visual cues to the reader. This proof-of-concept study is limited to the data from ex vivo samples, and additional work in human subjects with spondylolysis would be necessary to refine the models for clinical use. Nonetheless, this study shows that the utilization of UTE MRI and deep learning tools could be highly useful for the evaluation of isthmic spondylolysis.

Utility of ultrasonography in the diagnosis of lumbar spondylolysis in adolescent patients

BACKGROUND

This study aims to investigate the utility of the Doppler effect on ultrasonography for the diagnosis of very early- and early-stage lumbar spondylolysis in adolescent patients.

METHODS

In total, 76 adolescent patients with acute and subacute low back pain were prospectively enrolled, with 46 having lumbar spondylolysis and the remaining 30 having low back pain without spondylolysis. MRI and/or computed tomograms scans revealed very early- and early-stage lumbar spondylolysis. Furthermore, positive Doppler findings in ultrasonography around the area from the facet joint to the laminae were investigated.

RESULTS

There were no significant differences in age (p > 0.99) and body mass index (p = 0.11) between cases with and without spondylolysis. Very early- and early-stage spondylolysis were observed in 27.6% and 72.4% of patients, respectively. Positive power Doppler was 91.3% and 33.3% in cases with and without spondylolysis, respectively, which was significantly higher in spondylolysis (p < 0.001). The sensitivity and specificity of this positive power Doppler were 91.4% and 66.7%, respectively. Furthermore, the rate of positive power Doppler was significantly higher in early-stage spondylolysis (p = 0.02), with 75.0% and 97.6% sensitivity in very early- and early-stage spondylolysis, respectively.

CONCLUSIONS

A positive Doppler effect on ultrasonography is effective for screening very early- and early-stage spondylolysis in adolescent patients in an outpatient clinic.

Towards data-driven biopsychosocial classification of non-specific chronic low back pain: a pilot study

The classification of non-specific chronic low back pain (CLBP) according to multidimensional data could guide clinical management; yet recent systematic reviews show this has not been attempted. This was a prospective cross-sectional study of participants with CLBP (n = 21) and age-, sex- and height-matched pain-free controls (n = 21). Nervous system, lumbar spinal tissue and psychosocial factors were collected. Dimensionality reduction was followed by fuzzy c-means clustering to determine sub-groups. Machine learning models (Support Vector Machine, k-Nearest Neighbour, Naïve Bayes and Random Forest) were used to determine the accuracy of classification to sub-groups. The primary analysis showed that four factors (cognitive function, depressive symptoms, general self-efficacy and anxiety symptoms) and two clusters (normal versus impaired psychosocial profiles) optimally classified participants. The error rates in classification models ranged from 4.2 to 14.2% when only CLBP patients were considered and increased to 24.2 to 37.5% when pain-free controls were added. This data-driven pilot study classified participants with CLBP into sub-groups, primarily based on psychosocial factors. This contributes to the literature as it was the first study to evaluate data-driven machine learning CLBP classification based on nervous system, lumbar spinal tissue and psychosocial factors. Future studies with larger sample sizes should validate these findings.

Swinging injuries in competitive baseball players

Injuries are common in competitive baseball players and can occur in all facets of the game. The majority of the existing literature on injuries in baseball players has focused on injuries secondary to the overhead throw with very little attention given to injuries sustained while batting. The baseball swing is a complex, often violent, motion that predisposes batters to a variety of injuries affecting the spine, trunk, pelvis, and extremities. Knowledge of injury patterns that commonly occur during the baseball swing and radiologic findings important to the treating physician can help radiologists provide accurate imaging interpretations that appropriately guide patient management.

Spondylolysis

Spondylolysis is a bony defect of the pars interarticularis and most often results from repetitive stress. Although spondylolysis is usually asymptomatic, symptomatic spondylolysis is the most common cause of identifiable back pain in children and adolescent athletes. A thorough history and physical exam, as well as appropriate imaging studies are helpful in diagnosis. General first-ine therapy for spondylolysis is conservative and consists of rest from sports, core strengthening, as well as spinal bracing. Patients who have failed conservative therapy may consider surgical repair. This article aims to review the epidemiology, pathophysiology, presentation, and treatment options of spondylolysis.

The value of magnetic resonance imaging and computed tomography in the study of spinal disorders

Computed tomography (CT) and magnetic resonance imaging (MRI) have replaced conventional radiography in the study of many spinal conditions, it is essential to know when these techniques are indicated instead of or as complementary tests to radiography, which findings can be expected in different clinical settings, and their significance in the diagnosis of different spinal conditions. Proper use of CT and MRI in spinal disorders may facilitate diagnosis and management of spinal conditions. An adequate clinical approach, a good understanding of the pathological manifestations demonstrated by these imaging techniques and a comprehensive report based on a universally accepted nomenclature represent the indispensable tools to improve the diagnostic approach and the decision-making process in patients with spinal pain. Several guidelines are available to assist clinicians in ordering appropriate imaging techniques to achieve an accurate diagnosis and to ensure appropriate medical care that meets the efficacy and safety needs of patients. This article reviews the clinical indications of CT and MRI in different pathologic conditions affecting the spine, including congenital, traumatic, degenerative, inflammatory, infectious and tumor disorders, as well as their main imaging features. It is intended to be a pictorial guide to clinicians involved in the diagnosis and treatment of spinal disorders.

Union evaluation of lumbar spondylolysis using MRI and CT in adolescents treated conservatively

BACKGROUND

This study evaluated the union rate of acute lumbar spondylolysis in patients treated conservatively, according to the protocol.

METHODS

The subjects included high school students and younger patients who were diagnosed with lumbar spondylolysis presenting bone marrow edema. We investigated the union rate, the period until union, unilateral or bilateral, vertebral level, laterality (right or left), and pathological stage at the first visit. Some unilateral cases included bilateral spondylolysis with contralateral pseudarthrotic lesion; therefore, the union rate of the "true" unilateral case in which the contralateral side was normal was calculated. We excluded multi-level lesions.

RESULTS

With conservative treatment for lumbar spondylolysis of 189 lesions in 142 cases, 144 healed and 45 were considered as nonunion. The average treatment period until union was 106 days. The union of "true" unilateral cases in which the contralateral side was normal was noted in 68/71 lesions, but that of bilateral cases was noted in 71/94 lesions. The union in L3, L4, and L5 vertebrae was noted in 15/17, 40/49, and 89/123 lesions, respectively. The union was observed in 63/87 on the right and 86/102 on the left. The union was noted in the pre-lysis, early, and progressive stages in 36/39, 81/97, and 27/53 lesions, respectively. Furthermore, the union was noted in stages 0, 1a, 1b, 1c, and 2 in 13/15, 47/52, 30/36, 34/42, and 20/44 lesions, respectively.

CONCLUSION

Accurate union evaluation using CT and MRI showed a union rate of 76% with conservative treatment for spondylolysis. The union rate of the "true" unilateral cases in which the contralateral side was normal was 96%, which was significantly higher than that of the bilateral cases. Moreover, the union rate of lesions in the axial progressive stage and sagittal stage 2 was significantly lower than that of lesions in other stages.

STUDY DESIGN

clinical retrospective study.

Lumbosacral Spondylolysis and Spondylolisthesis

Repetitive stress on the lumbosacral spine during sporting activity places the athletic patient at risk of developing symptomatic pars defect. Clinical history, physical examination, and diagnostic imaging are important to distinguish spondylolysis from other causes of lower back pain. Early pars stress reaction can be identified with advanced imaging, before the development of cortical fracture or vertebral slip progression to spondylolisthesis. Conservative management is first-line for low-grade injury with surgical intervention indicated for refractory symptoms, severe spondylolisthesis, or considerable neurologic deficit. Prompt diagnosis and management of spondylolysis leads to good outcomes and return to competition for most athletes.

Presence of bone marrow oedema in asymptomatic elite fast bowlers: Implications for management

OBJECTIVES

1) Quantify the intensity of bone marrow oedema (BMO) present in the lumbar vertebrae of asymptomatic elite adult fast bowlers; 2) relate the intensity of BMO to bowling workload and lumbar bone stress injury (LBSI), and; 3) evaluate the utility of MRI screening to reduce the risk of LBSI.

METHODS

Thirty-eight elite Australian fast bowlers (21.6 ± 3.7 years) completed 48 screening MRI over 3 years. BMO intensity was quantified on MRI retrospectively. Standard practices for bowling workload monitoring and injury diagnosis were followed.

RESULTS

Clinically significant BMO (signal intensity ratio ≥ 2.0) was observed in 22 (46%, 95% CI 31-61) screening MRI. These bowlers had a total of 77 (IQR 45-115) days off between seasons, compared to 66 (IQR 41-94) days off for bowlers with a BMO intensity less than 2.0 (p = 0.510). Fifteen bowlers received follow up MRI as part of individualised management based on their screening MRI, of which less than five went on to develop LBSI in the subsequent season. There was no difference in days or balls bowled in the 12 months following screening MRI between those who sustained LBSI and those who did not.

CONCLUSIONS

BMO is common in asymptomatic bowlers. Identification of high-risk bowlers using screening MRI informs individualised management and may prevent progression to LBSI.

Factors associated with failure of bony union after conservative treatment of acute cases of unilateral lumbar spondylolysis

Background

If bone union is expected, conservative treatment is generally selected for lumbar spondylolysis. However, sometimes conservative treatments are unsuccessful. We sought to determine the factors associated with failure of bony union in acute unilateral lumbar spondylolysis with bone marrow edema including contralateral pseudarthrosis.

Methods

This study targeted unilateral lumbar spondylolysis treated conservatively in high school or younger students. Conservative therapy was continued until the bone marrow edema disappeared on MRI and bone union was investigated by CT. We conducted a univariate analysis of sex, age, pathological stage, lesion level complicating the contralateral bone defect, lesion level, and intercurrent spina bifida occulta, and variables with p < 0.1 were considered in a logistic regression analysis. An item with p < 0.05 was defined as a factor associated with failure of bony union.

Results

We found 92 cases of unilateral spondylolysis with bone marrow edema and 66 cases were successfully treated conservatively. Failure of bony union in unilateral lumbar spondylolysis with bone marrow edema was associated with progressive pathological stage (p = 0.004), contralateral pseudarthrosis (p < 0.001), and L5 lesion level (p = 0.002). The odds ratio was 20.0 (95% CI 3.0–193.9) for progressive pathological stage, 78.8 (95% CI 13–846) for contralateral pseudarthrosis, and 175 (95% CI 8.5–8192) for L5 lesion level.

Conclusions

Conservative therapy aiming at bony union is contraindicated in cases of acute unilateral spondylolysis when the pathological stage is progressive, the lesion level is L5, or there is contralateral pseudarthrotic spondylolysis.

Neural Arch Bone Marrow Edema and Spondylolysis in Adolescent Cheerleaders: A Case Series

Objective

Spondylolysis is 1 of the most common sources of low back pain in children and adolescents; however, there is still a great deal of confusion in regard to etiology, clinical presentation, and diagnostic imaging findings. It is imperative for clinicians to recognize that persistent low back pain is strongly indicative of spondylolysis, especially in high-performance athletes. This case series demonstrates a comprehensive diagnostic spectrum of spondylolysis and its treatment in 2 competitive adolescent cheerleaders.

Clinical Features

In case 1, a 12-year-old female competitive cheerleader presented with a gradual onset of subacute low back pain. Comprehensive clinical examination indicated imaging studies that identified bilateral L5 grade 1 stress reaction, consisting of neural arch bone marrow edema (BME). Treatment included spinal adjustments, rehabilitation, and myofascial therapy. In case 2, 15-year-old female competitive cheerleader presented with insidious chronic low back pain that was provocative with extension. Magnetic resonance imaging revealed a left L5 grade 1 pars interarticularis stress reaction. Computed tomography demonstrated right L5 pars grade 3 and left L5 healing spondylolysis. Treatment included spinal adjustments and rehabilitation exercises. She was also seen by a physical therapist who prescribed a lumbar spine flexion brace.

Intervention and Outcome

Diagnosis of BME and spondylolysis led to temporary cessation of cheerleading activities in cases 1 and 2. The individual in case 1 self-discharged with a list of rehabilitation exercises and was lost to follow-up. The individual in case 2 was able to return to sport pain free approximately 5 weeks after seeking treatment.

Conclusion

Spondylolysis is common in adolescent athletes, and the presence of BME precedes spondylolysis. Primary spine providers could consider this diagnosis in any adolescent, especially an athlete, who has persistent low back pain. Timely diagnosis will optimize treatment outcomes.

The Prevalence of Abnormalities in the Pediatric Spine on MRI: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

The aim of this study was to provide an overview of the prevalence of reported musculoskeletal abnormalities on magnetic resonance imaging (MRI) of the pediatric spine.

SUMMARY OF BACKGROUND DATA

Back pain is a common complaint and significant health issue, already in children. Several studies have investigated musculoskeletal abnormalities of the pediatric spine as possible cause of low back pain (LBP). However, it is not clear which abnormalities are the most prevalent among children.

METHODS

A systematic literature search on the prevalence of musculoskeletal spinal abnormalities on MRI in children was conducted in the Embase, Medline Ovid, and Cochrane CENTRAL databases. Risk of bias (RoB) was assessed using a checklist based on the Downs and Black checklist. General information on study and patient characteristics and the prevalence of spinal abnormalities were extracted from the studies. Prevalence data were presented in three subgroups: nonathletes without LBP, participants with LBP, and athletes. Prevalence data of the most reported abnormalities were pooled using random-effects proportion meta-analysis. The study protocol was prospectively registered in PROSPERO (CRD42017080543).

RESULTS

The search resulted in 16,783 articles, of which 31 articles (2373 participants) were included in this systematic review. Two-thirds of the studies had a low RoB. The pooled prevalence in nonathletes without LBP, participants with LBP, and athletes without LBP was respectively 22%, 44%, and 22% for disc degeneration, 1%, 38%, and 13% for herniated discs, 5%, 22%, and 11% for endplate changes, and 0%, 30%, and 6% for pars fractures.

CONCLUSION

Disc degeneration, herniated discs, endplate changes, and spondylolysis are the most reported spinal abnormalities on MRI in children in literature. Spinal abnormalities seen in adults are already prevalent in children with LBP, with the highest prevalence for disc degeneration and herniated discs.

LEVEL OF EVIDENCE

2.

Radiological healing of lumbar spine stress fractures in elite cricket fast bowlers

OBJECTIVES

Review magnetic resonance imaging (MRI) of elite adult fast bowlers with a history of lumbar spine stress fracture for evidence of bone healing. The findings will determine whether bone healing can occur in this population, and whether MRI may be used as a tool to assess bone healing and inform clinical decision making.

DESIGN

Retrospective cohort.

METHODS

Participants were elite Australian fast bowlers who sustained a lumbar spine stress fracture confirmed on MRI and had at least one subsequent MRI. Two radiologists independently reviewed all images.

RESULTS

Thirty-one fractures from 20 male fast bowlers were reviewed. Median maximum fracture size was 6mm (range 2-25mm). Twenty-five fractures achieved bone healing, with a median 203 (IQR 141-301) days between the initial MRI (to confirm diagnosis) and the MRI when bone healing was observed. Fracture size and signal intensity of bone marrow oedema were positively associated with the number of days to the MRI when bone healing was observed (r²=0.245, p<0.001 and r²=0.292, p<0.001 respectively). Fractures which occurred at the same site as a previously united fracture took longer to heal than the first fracture (median 276 days to the MRI when bone healing was observed compared to 114 days for first fracture; p=0.036).

CONCLUSIONS

Lumbar spine stress fractures in elite adult fast bowlers are capable of achieving complete bone healing, as demonstrated in the majority of bowlers in this study. Larger fractures, greater bone marrow oedema, and history of previous injury at the same site may require longer healing time which may be monitored with MRI.

Stress Injuries of the Spine in Sports

Spine sports stress injuries account for a significant amount of time loss at play in athletes, particularly if left unrecognized and allowed to progress. Spondylolysis makes up most of these stress injuries. This article focuses on spondylolysis, bringing together discussion from the literature on its pathomechanics and the different imaging modalities used in its diagnosis. Radiologists should be aware of the limitations and more importantly the roles of different imaging modalities in guiding and dictating the management of spondylolysis. Other stress-related injuries in the spine are also discussed including but not limited to pedicle fracture and apophyseal ring injury.

Spondylolysis in Young Athletes: An Overview Emphasizing Nonoperative Management

Lumbar spondylolysis is a unilateral or bilateral defect of the pars interarticularis, an isthmus of bone connecting the superior and inferior facet surfaces in the lumbar spine at a given level. Spondylolysis is common in young athletes participating in sports, particularly those requiring repetitive hyperextension movements. The majority of young athletes are able to return to full sport participation following accurate diagnosis and conservative management, including a structured treatment program. Surgical intervention for isolated pars injuries is seldom necessary. A progressive physical therapy (PT) program is an important component of recovery after sustaining an acute pars fracture. However, there is a paucity of literature detailing PT programs specific to spondylolysis. Here, we provide an overview of the epidemiology, natural history, radiographic evaluation, and management of pars fractures in young athletes. In addition, a detailed description of a physiotherapy program for this population that was developed at a spine center within an academic medical center is provided.

Ultrashort Time-to-Echo Magnetic Resonance Imaging at 3 T for the Detection of Spondylolysis in Cadaveric Spines: Comparison With CT

OBJECTIVES

The objective of this study was to compare the diagnostic performance and confidence of conventional, optimized, and ultrashort time to echo (UTE) magnetic resonance (MR) protocols for detection of simulated lumbar spondylolysis in human cadavers. In addition, we sought to demonstrate the feasibility of the UTE technique in subjects with and without spondylolysis.

MATERIALS AND METHODS

Four human lumbar spine specimens with 46 individual pars interarticularis were randomly left intact (n = 26) or received experimental osteotomy (n = 20) using a microsurgical saw to simulate spondylolysis. The specimens were imaged using a computed tomography (CT) scan along with 3 "Tiers" of MR protocols at 3 T: Tier 1, conventional lumbar MR protocol; Tier 2, optimized conventional protocol consisting of a sagittal oblique spoiled gradient recall echo and axial oblique T1 and short tau inversion recovery sequences; and Tier 3, a sagittal UTE MR sequence. Two blinded readers evaluated the images using a 4-point scale (1 = spondylolysis certainly absent, 2 = probably absent, 3 = probably present, 4 = certainly present) at each individual pars. For each imaging protocol, diagnostic performance (sensitivity, specificity, and area under the receiver operating characteristic curve, using the surgical osteotomy as the reference) and confidence were assessed and compared using the McNemar test. Furthermore, 2 human subjects were imaged with the conventional and UTE MR protocols to demonstrate feasibility in vivo.

RESULTS

Diagnostic performance was moderate for Tiers 1 and 2, with a moderate sensitivity (0.70 to 0.75) and high (1.00) specificity. In contrast, CT and Tier 3 UTE MR imaging had both high sensitivity (1.00) and specificity (1.00). The sensitivities of CT or Tier 3 were statistically greater than Tier 1 sensitivity (P = 0.041) and neared statistical significance when compared with Tier 2 sensitivity (P = 0.074). Area under the receiver operating characteristic curve was also significantly greater for CT and Tier 3 (each area = 1.00), compared with the areas for Tier 1 (0.89, P = 0.037) or Tier 2 (0.873, P = 0.024). Diagnostic confidences of CT or Tier 3 were much greater than other Tiers: Both Tiers 1 and 2 had a large percentage of uncertain (>60%, P < 0.001) or wrong interpretations (>10%, P < 0.001), unlike CT or Tier 3 (0% uncertain or wrong interpretations). Preliminary in vivo UTE images clearly depicted intact and fractured pars.

CONCLUSIONS

Our study demonstrated that the detection of pars fractures using a single sagittal UTE MR sequence is superior in performance and confidence to conventional and optimized MR protocols at 3 T, whereas matching those from CT evaluation. Furthermore, we demonstrated the feasibility of in vivo application of the UTE sequence in subjects with and without spondylolysis.

Spondylolysis 2019 update

PURPOSE OF REVIEW

Provide a comprehensive overview of lumbar spondylolysis, a frequent cause of lower back pain in children and adolescents, from evaluation to management.

RECENT FINDINGS

With the surge of structured sports participation in the pediatric population, spondylolysis is a common ailment that afflicts many young athletes due to rigorous competition that taxes the growing spine with repetitive extension and rotation.

SUMMARY

Spondylolysis is a fracture through the pars interarticularis. When a child presents with lower back pain, spondylolysis should be at the top of the differential. A thorough history and physical examination are essential. In addition, radiographs of the lumbar spine, anterior posterior and lateral views, MRI and, selectively, computed tomography are useful adjuncts to uncover a pars injury. Timely diagnosis facilitates early treatment which includes rest, optimizing bone health, brace treatment, and physical therapy. If delayed or untreated, spondylolysis may result in nonunion or pars defect. If symptomatic, patients may need surgery to fuse the lumbar facet joints or repair the par interarticularis.

VIBE MRI: an alternative to CT in the imaging of sports-related osseous pathology?

MRI is an excellent diagnostic tool in the imaging of sports-related musculoskeletal pathology; however, standard slice thickness acquisitions can lack the spatial resolution to accurately define and characterise osseous abnormalities. Standard MRI sequences may be supplemented with CT to reduce diagnostic uncertainty. We provide a clinical perspective, in the form of pictorial review, on the potential applications of 3D MRI sequences, specifically using volumetric interpolated breath-hold examination in the characterisation of various musculoskeletal osseous pathologies. The potential to negate the requirement for CT in a young radiation sensitive cohort is a clinically significant concept and suggests the requirement for further studies comparing the performance of volumetric MRI to CT.

Temporal Evolution of Disc in Young Patients with Low Back Pain and Stress Reaction in Lumbar Vertebrae

BACKGROUND AND PURPOSE

Although stress-induced bony changes often resolve with conservative treatment, the long-term effects of such mechanical stresses on intervertebral discs have not been studied. We aimed to assess the differences in the temporal evolution of disc in segments of the lumbar spine with and without signs of increased mechanical stresses.

MATERIALS AND METHODS

Using MR imaging performed >6 months apart, 2 radiologists evaluated lumbar intervertebral discs for degenerative changes affecting the annulus fibrosus, the nucleus pulposus, and the endplates in 42 patients (22 male, 20 female; mean age, 16.0 ± 3.7 years [range, 7-25 years]) with low back pain and imaging evidence of stress reaction/fracture in the lumbar spine. Data were analyzed for differences in the presence and progression of disc degeneration in stressed versus nonstressed segments.

RESULTS

At baseline, stressed discs had a higher burden of annular fissures, radial fissures, herniation, and nuclear degeneration. Endplate defect burden was comparable in stressed and control discs. At follow-up, the burden of new annular fissures and endplate defects was comparable for stressed and control discs. However, a higher proportion of stressed discs showed worsening nuclear signal intensity grade (14.3% versus 0% control discs; P = .008) and worsening nuclear degeneration grade (11.9% versus 0% control discs; P = .02). An increased risk of progressive nuclear degeneration of stressed discs was observed irrespective of the outcome of bony changes.

CONCLUSIONS

Stressed discs exhibit a higher burden of nuclear and annular degeneration at baseline. These discs have a higher risk of progressive nuclear degeneration irrespective of improvement or worsening of stress-related bony changes.

Imaging Pediatric Spondylolysis: A Systematic Review

STUDY DESIGN

A systematic review.

OBJECTIVE

The aim of this study was to provide an evidence-based recommendation for when and how to employ imaging studies when diagnosing back pain thought to be caused by spondylolysis in pediatric patients.

SUMMARY OF BACKGROUND DATA

Spondylolysis is a common structural cause of back pain in pediatric patients. The radiologic methods and algorithms used to diagnose spondylolysis are inconsistent among practitioners.

METHODS

A literature review was performed in PubMed and Cochrane databases using the search terms "spondylolysis," "pediatric," "adolescent," "juvenile," "young," "lumbar," "MRI," "bone scan," "CT," and "SPECT." After inclusion criteria were applied, 13 articles pertaining to diagnostic imaging of pediatric spondylolysis were analyzed.

RESULTS

Ten papers included sensitivity calculations for comparing imaging performance. The average sensitivity of magnetic resonance imaging (MRI) with computed tomography (CT) as the standard of reference was 81.4%. When compared with single-photon emission CT (SPECT), the average sensitivity of CT was 85% and the sensitivity of MRI was 80%. Thirteen studies made a recommendation as to how best to perform diagnostic imaging of patients with clinically suspected spondylolysis. When compared with two-view plain films, bone scans had seven to nine times the effective radiation dose, while four-view plain films and CT were approximately double. Of the diagnostic methods examined, MRI was the most expensive followed by CT, bone scan, four-view plain films, and two-view plain films.

CONCLUSION

Due to their efficacy, low cost, and low radiation exposure, we find two-view plain films to be the best initial study. With unusual presentations or refractory courses, practitioners should pursue advanced imaging. MRI should be used in early diagnosis and CT in more persistent courses. However, the lack of rigorous studies makes it difficult to formulate concrete recommendations.

LEVEL OF EVIDENCE

3.

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

BACKGROUND

Spondylolysis is common among the pediatric population, yet no formal systematic literature review regarding diagnostic imaging has been performed. The Scoliosis Research Society (SRS) requested an assessment of the current state of peer reviewed evidence regarding pediatric spondylolysis.

METHODS

Literature was searched professionally and citations retrieved. Abstracts were reviewed and analyzed by the SRS Evidence-Based Medicine Committee. Level I studies were considered to provide Good Evidence for the clinical question. Level II or III studies were considered Fair Evidence. Level IV studies were considered Poor Evidence. From 947 abstracts, 383 full texts reviewed. Best available evidence for the questions of diagnostic methods was provided by 27 studies: no Level I sensitivity/specificity studies, five Level II and two Level III evidence, and 19 Level IV evidence.

RESULTS

Pain with hyperextension in athletes is the most widely reported finding in history and physical examination. Plain radiography is considered a first-line diagnostic test for suspected spondylolysis, but validation evidence is lacking. There is consistent Level II and III evidence that pars defects are detected by advanced imaging in 32% to 44% of adolescents with spondylolysis based on history and physical. Level III evidence that single-photon emission computed tomography (SPECT) is superior to planar bone scan and plain radiographs but limited by high rates of false-positive and false-negative results and by high radiation dose. Computed tomography (CT) is considered the gold standard and most accurate modality for detecting the bony defect and assessment of osseous healing but exposes the pediatric patient to ionizing radiation. Magnetic resonance imaging (MRI) is reported to be as accurate as CT and useful in detecting early stress reactions of the pars without a fracture.

CONCLUSION

Plain radiographs are widely used as screening tools for pediatric spondylolysis. CT scan is considered the gold standard but exposes the patient to a significant amount of ionizing radiation. Evidence is fair and promising that MRI is comparable to CT.

Time course of osteoporotic vertebral fractures by magnetic resonance imaging using a simple classification: a multicenter prospective cohort study

This study revealed the time course of osteoporotic vertebral fracture by magnetic resonance imaging using a simple classification. Signal changes were associated with the compression degree and mobility of the fractured vertebral body. This classification showed sufficient reliability in categorizing magnetic resonance imaging findings of osteoporotic vertebral fractures.

INTRODUCTION

Magnetic resonance imaging (MRI) is useful in diagnosing osteoporotic vertebral fractures (OVFs). This study investigated the time course of OVFs by MRI using a simple classification.

METHODS

This multicenter cohort study was performed from 2012 to 2015. Consecutive patients with ≤2-week-old OVFs were enrolled in 11 institutions. MRI was performed at enrollment and at 1-, 3-, 6-, and 12-month follow-up. Signal changes on T1-weighted imaging (T1WI), T2WI, and short τ inversion recovery (STIR) were classified according to signal intensity. Height and angular motion of vertebral bodies were also measured.

RESULTS

The 6-month follow-up was completed by 153 patients. At enrollment, fractured vertebrae signal changes were 43 % diffuse and 57 % confined low on T1WI; on T2WI, 56, 24, and 5 % were confined low, high, and diffuse low, respectively; on STIR, 100 % were high. On T1WI, diffuse low remained most common (90 % at 1 month and 60 % at 3 months) until 6 and 12 months, when most were confined low (54 and 52 %, respectively). On T2WI, confined low remained most common (decreasing to 41 % at 12 months). On STIR, high signal change was shown in 98, 87, and 64 % at 3, 6, and 12 months, respectively. At 3, 6, and 12 months, diffuse low signal change was associated with significantly lower vertebral height, and high signal change was associated with significantly greater angular motion.

CONCLUSIONS

MRI signal changes were associated with the compression degree and angular motion of fractured vertebrae. This classification showed sufficient reliability in categorizing MRI findings of OVFs.

Diagnostic accuracy of 3-T magnetic resonance imaging with 3D T1 VIBE versus computer tomography in pars stress fracture of the lumbar spine

OBJECTIVE

To compare the diagnostic accuracy of 3-T magnetic resonance imaging (MRI) with thin-slice 3D T1 VIBE sequence to 128-slice computer tomography (CT) in pars stress fractures of the lumbar spine.

MATERIALS AND METHODS

3-T MRI and CT of 24 patients involving 70 pars interarticularis were retrospectively reviewed by four blinded radiologists. The fracture morphology (complete, incomplete, or normal) was assessed on MRI and CT at different time points. Pars interarticularis bone marrow edema (present or absent) was also evaluated on MRI.

RESULTS

In total, 14 complete fractures, 31 incomplete fractures and 25 normal pars were detected by CT. Bone marrow edema was seen in seven of the complete and 25 of the incomplete fractures. The overall sensitivity, specificity and accuracy of MRI in detecting fractures (complete and incomplete) were 97.7, 92.3, and 95.7 %, respectively. MRI was 100 % accurate in detecting complete fractures. For incomplete fractures, the sensitivity, specificity, and accuracy of MRI were 96.7, 92.0, and 94.6 %, respectively.

CONCLUSIONS

3-T MRI with thin-slice 3D T1 VIBE is 100 % accurate in diagnosing complete pars fractures and has excellent diagnostic ability in the detection and characterization of incomplete pars stress fractures compared to CT. MRI has the added advantages of detecting bone marrow edema and does not employ ionizing radiation.

Atypical, unusual, and misleading imaging presentations of spondylolysis

Although lumbar spondylolysis is a widely known and easily recognizable condition in its typical presentation, there are some less well-known forms that may occasionally be challenging and/or demand special attention on imaging. Examples include: acute and/or incomplete lesions; unilateral defects; lesions at unusual levels (cervical, upper lumbar, and multi-level spondylolyses); iatrogenic lesions; non-isthmic spondylolysis; and spondylolysis related to underlying diseases. In addition to their atypical, uncommon or confusing imaging presentations, these forms of spondylolysis are far rarer than the classic type and have been described, to a great extent, in the surgical literature, thus reducing the awareness of radiologists about them and raising the potential for misdiagnosis and inadequate treatment. In this review the authors address these special manifestations of spondylolysis, stressing the more important features to be considered in the differential diagnosis and the impact of a precise diagnosis of spondylolysis on the patient's care.

Use of magnetic resonance imaging in the evaluation of spondylolysis

BACKGROUND

In early studies, magnetic resonance imaging (MRI) had low sensitivity and positive predictive value in the evaluation of the pars interarticularis pathology; however, more recent reports have suggested an expanded role for MRI. The purpose of the present study was to evaluate the effectiveness of MRI in the diagnosis of pars injuries and compare it to computed tomography (CT), which was used as the reference "gold standard" for the detection of fractures.

METHODS

The radiographic and clinic data of 93 adolescents and young adults with a presumptive diagnosis of spondylolysis based upon history and clinic examination were reviewed. Only 26 patients who had MRI and CT images obtained within 30 days of each other were included. All images were reviewed by a fellowship-trained musculoskeletal radiologist and fellowship-trained pediatric orthopaedist.

RESULTS

Overall, 39 individual pars lesions (stress reaction or fracture) were identified. MRI was effective in identifying 36 pars lesions. MRI identified 11 lesions in 9 patients with negative CT. Seven of these lesions were stress reactions (grade 1), whereas 4 were frank fractures. Three pars injuries were noted on CT while the MRI was negative.

CONCLUSIONS

MRI is an effective method (92% sensitivity) for detecting pars injuries. It can detect stress reactions when a fracture is not visible on CT scan, allowing early treatment of these prelysis lesions. The 92% sensitivity of MRI is comparable with that of other diagnostic modalities such as bone scan, with the advantage of no radiation exposure. MRI should be strongly considered as the advanced imaging modality of choice in the evaluation of patients with suspected spondylolysis.

LEVEL OF EVIDENCE

Level III-diagnostic study.

CT outperforms radiographs at a comparable radiation dose in the assessment for spondylolysis

BACKGROUND

Lumbar spondylolysis, a unilateral or bilateral fracture at pars interarticularis, is a common cause of low back pain in children. The initial imaging study in the diagnosis of lumbar spondylolysis has historically been lumbar spine radiographs; however, radiographs can be equivocal or false-negative. Definitive diagnosis can be achieved with computed tomography (CT), but its use has been limited due to the dose of ionizing radiation to the patient.

OBJECTIVE

By limiting the z-axis coverage to the relevant anatomy and optimizing the CT protocol, we are able to provide a definitive diagnosis of fractures of the pars interarticularis at comparable or lower radiation dose than commonly performed lumbar spine radiographs. As there is no gold standard for the diagnosis of spondylolysis besides surgery, we compared interobserver agreement and degree of confidence to determine which modality is preferable.

MATERIALS AND METHODS

Sixty-two patients with low back pain ages 5-18 years were assessed for the presence of spondylolyis. Forty-seven patients were evaluated by radiography and 15 patients were evaluated by limited field-of-view CT. Both radiographic and CT examinations were assessed anonymously in random order for the presence or absence of spondylolyisis by six raters. Agreement was assessed among raters using a Fleiss Kappa statistic for multiple raters.

RESULTS

CT provided a significantly higher level of agreement among raters than radiographs (P < 0.001). The overall Kappa for rater agreement with radiographs was 0.24, 0.34 and 0.40 for 2, 3 or 4 views, respectively, and 0.88 with CT.

CONCLUSION

Interobserver agreement is significantly greater using limited z-axis coverage CT when compared with radiographs. Radiologist confidence improved significantly with CT compared to radiographs regardless of the number of views.

Current Evidence Regarding the Etiology, Prevalence, Natural History, and Prognosis of Pediatric Lumbar Spondylolysis: A Report from the Scoliosis Research Society Evidence-Based Medicine Committee

STUDY DESIGN

Structured literature review.

OBJECTIVES

To assess the current state of evidence as a first step in the development of practice guidelines for pediatric spondylolysis.

SUMMARY OF BACKGROUND DATA

Progress in published medical knowledge, changes in societal expectations, and developments in health care economics have led medical organizations to develop evidence-based documents and products.

METHODS

A comprehensive literature search for pediatric spondylolysis was performed with the assistance of a medical librarian. The authors reviewed citations and abstracts. Abstracts were reviewed for exclusions and data from included studies were analyzed by committee. A total of 44 articles provided the best available evidence for the questions of etiology, prevalence, natural history, and prognosis: 9 were graded as level I evidence, 23 were level II, 3 were level III, and 9 were level IV. No level V studies were included in the final list.

RESULTS

There is good evidence that pediatric lumbar spondylolysis is an acquired fracture of the pars interarticularis that can occur unilaterally or bilaterally. Evidence shows that when chronic, bilateral pars defects develop, 43% to 74% of patients will progress to grade 1 or 2 spondylolisthesis. In addition, unilateral, incomplete, and early lesions can obtain bony union. With or without bony union or spondylolisthesis, short-term symptom resolution is the norm. Long-term prognosis is less clear, but there is fair evidence that most patients will have lumbar symptoms compared with the general population. There is also fair evidence that some patients will develop significant symptoms as adults and will undergo surgical treatment. There is insufficient knowledge to predict which patients will continue to do well in the long term with conservative or no treatment and which patients will develop symptoms significant enough to warrant early intervention.

CONCLUSIONS

The current medical literature provides fair to good evidence for clinically relevant questions regarding the etiology, prevalence, natural history, and prognosis of pediatric spondylolysis.

L5 spondylolysis/spondylolisthesis: a comprehensive review with an anatomic focus

INTRODUCTION

Spondylolysis is most commonly observed in the lumbar spine, particularly L5, and is associated with spondylolisthesis, or anterior "slippage" of a vertebra in relation to an adjacent vertebra. Isthmic spondylolisthesis is the result of a pars interarticularis defect and will be the only type of spondylolisthesis addressed in this review.

CONCLUSIONS

Spondylolysis and spondylolisthesis represent a relatively common cause of low back pain, especially in young athletes, and a less common cause of neurologic compromise. When discovered in a symptomatic patient with corroborating imaging findings, early intervention provides an excellent prognosis. Herein, we review the anatomy and pathology of spondylosis and spondylolisthesis of the L5 vertebra.

Diagnosis of radiographically occult lumbar spondylolysis in young athletes by magnetic resonance imaging

BACKGROUND

The early stages of spondylolysis are extremely difficult to diagnose on plain radiography. Although several studies have examined changes in active spondylolysis on magnetic resonance imaging (MRI), no studies to date have determined the onset frequency of active spondylolysis detectable on MRI but occult on plain radiography. Moreover, the clinical features of active spondylolysis described in the literature do not facilitate the differentiation of this condition from other causes of low back pain.

PURPOSE

This study aimed to evaluate the usefulness of MRI in diagnosing active spondylolysis early and in determining the prevalence of active spondylolysis in cases where findings were not detected on plain radiography. In addition, specific clinical features to aid in the early detection of active spondylolysis were evaluated.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients were 200 consecutive young athletes (144 boys and 56 girls; mean age, 14.1 ± 1.5 y) with low back pain. All patients were examined by plain radiography (188 with negative findings and 12 with unclear findings of spondylolysis) and MRI. Computed tomography (CT) was performed only for patients with high intensity changes of the pedicle observed on MRI. The presence or absence of low back pain was examined during lumbar spine extension and flexion. The Kemp test on the right and left sides and percussion of the vertebral spinous process were also performed.

RESULTS

Ninety-seven (48.5%) patients showed evidence of active spondylolysis on MRI, findings that had been missed by plain radiography. These pars defects were organized into the following categories based on CT findings: nonlysis stage, 52; very early stage, 37; late early stage, 22; progressive stage, 10; and terminal stage, 0. No significant physical examination factors were identified that could assist in the early detection of active spondylolysis.

CONCLUSION

The MRI results suggest a high rate of active spondylolysis in young athletes with low back pain who test negative for spondylolysis on plain radiography. Magnetic resonance imaging appears to be useful in the early diagnosis of active spondylolysis, especially as we found no significant physical examination factors that could assist in early detection.

Imaging of stress fractures of the spine

Back pain caused by stress fractures, fatigue, or insufficiency, affects varied patient populations based on the level of physical activity and bone mineral density. Stress fractures may involve the vertebral body, pars interarticularis, and the pedicle; often overlooked are stress fractures of the sacrum or bony pelvis, which can mimic pain of spinal origin and delay diagnosis. The choice of optimal imaging (radiographs, nuclear medicine, magnetic resonance imaging, and computed tomography) also depends on the patient population under study and the clinically suspected diagnosis. The diagnosis typically determines which imaging modality is best to follow healing or progression.

Taking the stress out of evaluating stress injuries in children

Pediatric stress injuries result from a mismatch between (a) the burden of activity on growing bone and cartilage and (b) their intrinsic biomechanical properties. Although the presentation of stress injuries varies with the specific physical activity and the site of injury, in children it varies primarily with the degree of skeletal maturation. During the past several years, there has been a substantial increase in the incidence of pediatric stress injuries. The differential diagnosis of a stress injury in a child or adolescent can be challenging because the injury sometimes can appear aggressive at imaging assessment. Awareness of the spectrum of imaging features of stress injuries can help the radiologist to reach the correct diagnosis and prevent unnecessary anxiety. This review depicts the range of stress injuries in children and adolescents in various anatomic locations, with emphasis on their appearances at magnetic resonance imaging.

The imaging and management of nonconsecutive pars interarticularis defects: a case report and review of literature

BACKGROUND CONTEXT

Lumbar spondylolysis is a well-recognized condition occurring in adolescents because of repetitive overuse in sports. Multiple-level spondylolysis involving consecutive lower lumbar segments are rare. Several authors have reported failure of conservative treatment in the management of multiple-level pars fractures.

STUDY DESIGN

A case report and review of previous literature is presented.

OBJECTIVE

The objectives of this case report were to present a rare case of pars fracture involving nonconsecutive segments and discuss image findings and treatment.

METHODS

The patent's history, clinical examination, computed tomography (CT), magnetic resonance imaging (MRI) findings, and treatment are reported. We also discuss the pathogenesis, various treatment options, and review the literature.

RESULTS

We present the fourth case of bilateral pars fractures involving nonconsecutive lower lumbar spine segments of L3 and L5, in a 16-year-old young adolescent footballer who presented with 4-month history of constant low back pain. After 1 year of conservative management, the more acute fractures at L3 showed complete bony union, symptomatic pain relief, and return to full sporting activity.

CONCLUSION

We report a rare case of bilateral pars fractures involving nonconsecutive segments. Multiplane reconstruction of CT images and MRI are very useful in planning treatment and follow-up. Conservative management may be used to treat multilevel nonconsecutive pars fractures.

Lumbar spondylolysis: a review

Spondylolysis is an osseous defect of the pars interarticularis, thought to be a developmental or acquired stress fracture secondary to chronic low-grade trauma. It is encountered most frequently in adolescents, most commonly involving the lower lumbar spine, with particularly high prevalence among athletes involved in certain sports or activities. Spondylolysis can be asymptomatic or can be a cause of spine instability, back pain, and radiculopathy. The biomechanics and pathophysiology of spondylolysis are complex and debated. Imaging is utilized to detect spondylolysis, distinguish acute and active lesions from chronic inactive non-union, help establish prognosis, guide treatment, and to assess bony healing. Radiography with satisfactory technical quality can often demonstrate a pars defect. Multislice CT with multiplanar reformats is the most accurate modality for detecting the bony defect and may also be used for assessment of osseous healing; however, as with radiographs, it is not sensitive for detection of the early edematous stress response without a fracture line and exposes the patient to ionizing radiation. Magnetic resonance (MR) imaging should be used as the primary investigation for adolescents with back pain and suspected stress reactions of the lumbar pars interarticularis. Several imaging pitfalls render MR imaging less sensitive than CT for directly visualizing the pars defects (regional degenerative changes and sclerosis). Nevertheless, the presence of bone marrow edema on fluid-sensitive images is an important early finding that may suggest stress response without a visible fracture line. Moreover, MR is the imaging modality of choice for identifying associated nerve root compression. Single-photon emission computed tomography (SPECT) use is limited by a high rate of false-positive and false-negative results and by considerable ionizing radiation exposure. In this article, we provide a review of the current concepts regarding spondylolysis, its epidemiology, pathogenesis, and general treatment guidelines, as well as a detailed review and discussion of the imaging principles for the diagnosis and follow-up of this condition.

Diagnostic accuracy of magnetic resonance imaging versus computed tomography in stress fractures of the lumbar spine

AIM

To compare the diagnostic accuracy of magnetic resonance imaging (MRI) with computed tomography (CT) in stress fractures of the lumbar spine.

MATERIALS AND METHODS

Radiological and clinical data from 57 adolescents and young adults with a diagnosis of stress injury of the lumbar spine were retrospectively reviewed. All cases had undergone both 1.5 T MRI and 16-section CT examinations. All MRI and CT images were retrospectively reviewed and evaluated in separate sessions. The fracture morphology (complete/incomplete, localization) and vertebral levels were noted at both the CT and MRI examinations. Bone marrow/peri-osseous soft-tissue oedema was also determined at MRI.

RESULTS

In total, 73 complete and 32 incomplete stress fractures were detected with CT. Sixty-seven complete, 24 incomplete fractures and eight stress reactions were detected using MRI in the same study group. Marrow oedema was also seen in eight of the complete and 20 of the incomplete fractures. The specificity, sensitivity, and accuracy of MRI in detecting fracture lines were 99.6, 86.7, and 97.2%, respectively. MRI was more accurate at the lower lumbar levels in comparison to upper lumbar levels.

CONCLUSION

MRI has a similar diagnostic accuracy to CT in determining complete fractures with or without accompanying marrow oedema and incomplete fractures with accompanying marrow oedema, especially at the lower lumbar levels, which constitutes 94% of all fractures. At upper lumbar levels and in the incomplete fractures of the pars interarticularis with marked surrounding sclerosis, MRI has apparent limitations compared to CT imaging.

Imaging of back pain in children

While back pain presents less frequently in children than in adults, it still poses a significant clinical challenge with respect to making a firm diagnosis and developing an effective treatment plan. When children have back pain and medical attention is sought, an underlying pathology is usually suspected. Pediatric patients are evaluated, first, with a complete clinical history and examination and, second, by an imaging work-up that is based on initial findings, including the child's age and size, signs and symptoms, and suspected etiology. This article describes 1) the epidemiology of back pain in children, 2) the imaging work-up used, and 3) the correlation of imaging findings with disease entities that may cause back pain in the pediatric patient. The list of diseases giving rise to back pain is not meant to be exhaustive but rather reflective of the most commonly identified pathologies and disorders among young children and adolescents, from athletic injuries to lethal cancers.