Spondylolysis is frequently missed by MRI in adolescents with back pain

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.

Emergency MRI in Spine Trauma of Children and Adolescents-A Pictorial Review

Severe spinal trauma is uncommon in the pediatric population, but due to the potentially devastating consequences of missed injury, it poses a diagnostic challenge in emergency departments. Diagnostic imaging is often needed to exclude or confirm the injury and to assess its extent. Magnetic resonance imaging (MRI) offers an excellent view of both bony and soft tissue structures and their traumatic findings without exposing children to ionizing radiation. Our pictorial review aims to demonstrate the typical traumatic findings, physiological phenomena, and potential pitfalls of emergency MRI in the trauma of the growing spine.

Diagnostic Utility of Double-Echo Steady-State (DESS) MRI for Fracture and Bone Marrow Edema Detection in Adolescent Lumbar Spondylolysis

To evaluate the ability of double-echo steady-state (DESS) MRI to detect pars interarticularis fracture and bone marrow edema (BME) in spondylolysis, 500 lumber pars interarticularis from 50 consecutive patients (38 males and 12 females, mean age 14.2 ± 3.28 years) with spondylolysis who underwent both MRI and CT within 1 week were evaluated. All participants were young athletes who complained of lower back pain. Fractures were classified into four grades and CT was used as a reference; BME was evaluated in a binary manner and STIR was used as a reference. The diagnostic performance of fractures on DESS and T1WI, and BME on DESS was assessed by two radiologists independently. For fracture detection, DESS showed high diagnostic performance at a sensitivity of 94%, specificity of 99.5%, and accuracy of 98.8%, whereas T1WI showed lower sensitivity (70.1%). Fracture grading performed by DESS showed excellent agreement with CT grading (Kappa = 0.9). For BME, the sensitivity, specificity, and accuracy of DESS were 96.5%, 100%, and 99.6%, respectively. The inter-rater agreement of DESS for fracture and BME was 0.8 and 0.85, respectively. However, the inter-rater agreement for fracture on T1WI was 0.52. DESS had high diagnostic performance for fracture and BME in pars interarticularis. In conclusion, DESS had potential to detect all critical imaging findings in spondylolysis and may replace the role of CT.

Pediatric Back Pain: A Scoring System to Guide Use of Magnetic Resonance Imaging

BACKGROUND

The prevalence of back pain in the pediatric population is increasing, and the workup of these patients presents a clinical challenge. Many cases are selflimited, but failure to diagnose a pathology that requires clinical intervention can carry severe repercussions. Magnetic resonance imaging (MRI) carries a high cost to the patient and health care system, and may even require procedural sedation in the pediatric population. The aim of this study was to develop a scoring system based on pediatric patient factors to help determine when an MRI will change clinical management.

METHODS

This is a retrospective cohort analysis of consecutive pediatric patients who presented to clinic with a chief complaint of back pain between 2010 and 2018 at single orthopaedic surgery practice. Comprehensive demographic and presentation variables were collected. A predictive model of factors that influence whether MRI results in a change in management was then generated using cross-validation least absolute shrinkage and selection operator logistic regression analysis.

RESULTS

A total of 729 patients were included, with a mean age of 15.1 years (range: 3 to 20 y). Of these, 344 (47.2%) had an MRI. A predictive model was generated, with nocturnal symptoms (5 points), neurological deficit (10 points), age (0.7 points per year), lumbar pain (2 points), sudden onset of pain (3.25 points), and leg pain (3.75 points) identified as significant predictors. A combined score of greater than 9.5 points for a given patient is highly suggestive that an MRI will result in a change in clinical management (specificity: 0.93; positive predictive value: 0.92).

CONCLUSIONS

A predictive model was generated to help determine when ordering an MRI may result in a change in clinical management for workup of back pain in the pediatric population. The main factors included the presence of a neurological deficit, nocturnal symptoms, sudden onset, leg pain, lumbar pain, and age. Care providers can use these findings to better determine if and when an MRI might be appropriate.

LEVEL OF EVIDENCE

Level III-diagnostic study.

Clinical Manifestations and Diagnosis of Axial Spondyloarthritis

BACKGROUND

Axial spondyloarthritis (axSpA) is a chronic, rheumatic disease characterized by inflammation of the sacroiliac joint, spine, and entheses. Axial spondyloarthritis affects up to 1.4% of adults in the United States and is associated with decreased quality of life, increased mortality, and substantial health care-related costs, imposing a high burden on patients, their caregivers, and society.

SUMMARY OF WORK

Diagnosing axSpA can be difficult. In this review, we seek to help rheumatologists in recognizing and diagnosing axSpA.

MAJOR CONCLUSIONS

A discussion of challenges associated with diagnosis is presented, including use and interpretation of imaging, reasons for diagnostic delays, differences in disease presentation by sex, and differential diagnoses of axSpA.

FUTURE RESEARCH DIRECTIONS

The early diagnosis of axSpA and advances in available therapeutic options have improved patient care and disease management, but delays in diagnosis and treatment remain common. Additional research and education are critical for recognizing diverse axSpA presentations and optimizing management early in the course of disease.

Inter-Disciplinary Conservative Management of Bilateral Non-United Lumbar Pars Defects in a Junior Elite Golfer

The prevalence of spondylolysis amongst adolescent athletes presenting with low back pain has been reported as high as 47-55%. Youth athletes participating in sports involving movements combining compression, extension and rotation appear most susceptible. As such, young golfers are a high-risk group, particularly given the high shear and compressive forces associated with the golf swing action. This is compounded by a culture which encourages very high practice volumes, typically poorly monitored. Although non-operative interventions are deemed the gold-standard management for this condition, surgery is indicated for more severe presentations and cases of 'failed' conservative management. The case presented herein outlines an inter-disciplinary, non-operative management of a 17-year old elite golfer with a moderate to severe presentation. A 4-stage model of reconditioning is outlined, which may be of use to practitioners given the paucity of rehabilitation guidelines for this condition. The report highlights the benefits of a graded program of exercise-based rehabilitation over the typically prescribed "12 weeks rest" prior to a return to the provocative activity. It also supports existing evidence that passive therapeutic approaches should only be used as an adjunct to exercise, if at all in the management of spondylolysis. Finally, and crucially, it also underlines that to deem non-surgical rehabilitation 'unsuccessful' or 'failed', clinicians should ensure that (long-term) exercise was included in the conservative approach.

LEVEL OF EVIDENCE

4-Case Report.

Bony stress in the lumbar spine is associated with intervertebral disc degeneration and low back pain: a retrospective case-control MRI study of patients under 25 years of age

PURPOSE

Abnormal stress in the lumbar vertebra, also known as bony stress, can be a precursor to degenerative changes which may manifest as low back pain (LBP). However, the prevalence of bony stress in the lumbar spine and its relationship with degenerative changes and LBP is unclear. The purpose of this study was to evaluate the prevalence of bony stress in the lumbar spine and its relationship with intervertebral disc (IVD) degeneration, facet osteoarthritis and LBP in patients under 25 years of age.

METHODS

A retrospective case-control study of 130 patients under 25 years of age was conducted from a population of 493 patients who had lumbar MRI across three imaging centres over three years. A cohort of 55 consecutive patients with bony stress was identified. A control group of consecutive patients (n = 75) without bony stress was also selected from the population.

RESULTS

Bony stress was prevalent in 11% (95% CI [8.4-14.5%]) of patients and was not diagnosed in 36% (95% CI [22-55%]) of these cases. Patients with bony stress had over twofold (OR 2.3, 95% CI [1.1-4.8]) and fivefold (OR 5.3, 95% CI [2.11-13.3]) higher likelihood of having IVD degeneration and LBP, respectively, when compared with the control group. Bony stress was not found to be associated with facet osteoarthritis.

CONCLUSION

Bony stress in the lumbar spine was prevalent in 11% of patients under 25 years of age. It was commonly undiagnosed in radiology reports (not reported in 36% of the cases). Being significantly associated and with an increased likelihood of IVD degeneration and LBP, we posit that bony stress is likely a symptomatic and clinically meaningful diagnostic entity in the assessment of LBP. These slides can be retrieved under Electronic Supplementary Material.

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.

Lumbar Spine Injuries in Sports: Review of the Literature and Current Treatment Recommendations

Low back pain is one of the most prevalent complaints of athletes at all levels of competition. The purpose of this literature review is to provide an overview of sport-specific injuries and treatment outcomes that can be used by healthcare providers to better recognize injury patterns and treatment options for different groups of athletes. To our knowledge, no prior comprehensive review of lumbar spine injuries in sports is currently available in the literature, and it is essential that healthcare providers understand the sport-specific injury patterns and treatment guidelines for athletes presenting with low back pain following an athletic injury. Injury mechanisms were found to vary significantly by sport, although some broad recommendations can be made with regards to optimal treatment for these injuries and return to play. Additionally, it was found that certain treatments were more beneficial and resulted in higher rates of return to play depending on the specific sport of the injured athlete. Healthcare providers need to be aware of the different injury patterns seen in specific sports in order to properly evaluate and treat these injuries. Furthermore, an individualized treatment plan needs to be selected in a sport-specific context in order to meet the needs of the athlete in the short and long term.

Diagnostic Accuracy of Magnetic Resonance Imaging and Computed Tomography Scan in Young Athletes With Spondylolysis

The objective of this study was to determine diagnostic accuracy of magnetic resonance imaging (MRI) and computed tomography (CT) scans in young athletes diagnosed with spondylolysis. A cross-sectional study was used. Twenty-two young athletes (14.7 ± 1.5 years) were diagnosed as spondylolysis based on a single-photon emission CT. Following the diagnosis, participants underwent MRI and CT scan imaging tests on the same day. The sensitivity and false-negative rate of the MRI and CT scans were analyzed. MRI test confirmed 13 (+) and 9 (-) results while CT test showed 17 (+) and 5 (-) results. The sensitivity and false-negative rate of MRI were, respectively, 59.1% (95% confidence interval [CI] = 36.7% to 78.5%) and 40.9% (95% CI = 21.5% to 63.3%). Furthermore, the sensitivity and false-negative rate of CT scan were 77.3% (95% CI = 54.2% to 91.3%) and 22.7% (95% CI = 0.09% to 45.8%). Our results indicated that CT scan is a more accurate imaging modality to diagnose spondylolysis compared with MRI in young athletes.

Back Pain in a Pediatric Emergency Department: Etiology and Evaluation

OBJECTIVES

Back pain is an uncommon chief complaint in the pediatric emergency department (ED). However, there are serious underlying conditions requiring prompt diagnosis and treatment. While the etiology is usually benign, variation exists in the evaluation. The study purpose was to describe pediatric patients who presented to the ED with back pain and evaluate for associations with laboratory and radiologic abnormalities indicative of underlying musculoskeletal pathology.

METHODS

A retrospective review was conducted of patients aged birth to 18 years who presented to a pediatric ED with a chief complaint of back pain during a 1-year period. Primary outcome was discharge diagnosis, categorized as nonpathologic back pain, pathologic back pain, and other etiologies. Descriptive statistics were used.

RESULTS

Two-hundred thirty-two patient encounters were reviewed, with 177 included in data analysis. A nonpathologic diagnosis of back pain was found in 76.8% of visits. Back pain and back or muscle strain were the most common diagnoses. Pathologic back pain diagnoses represented 2.3% of visits. Radiologic imaging was performed in 37.9%. Positive findings were noted in 16.9% of radiographs; no abnormalities were noted on computed tomography scan or magnetic resonance imaging. Laboratory studies were conducted in 35%. Abnormal plain radiographs were associated with a pathologic diagnosis of back pain (P < 0.001).

CONCLUSIONS

Most pediatric patients presenting to the ED with back pain were found to have a nonpathologic etiology and were discharged. Among those with a pathologic back pain diagnosis, abnormal radiograph findings were the only statistically significant factor, whereas laboratory studies, computed tomography scans, and magnetic resonance imaging scans were less indicative.

Bone scintigraphy in patients with pain

Nuclear medicine imaging is widely used in pain medicine. Low back pain is commonly encountered by physicians, with its prevalence from 49% to 70%. Computed tomography (CT) or magnetic resonance imaging (MRI) are usually used to evaluate the cause of low back pain, however, these findings from these scans could also be observed in asymptomatic patients. Bone scintigraphy has an additional value in patients with low back pain. Complex regional pain syndrome (CRPS) is defined as a painful disorder of the extremities, which is characterized by sensory, autonomic, vasomotor, and trophic disturbances. To assist the diagnosis of CRPS, three-phase bone scintigraphy is thought to be superior compared to other modalities, and could be used to rule out CRPS due to its high specificity. Studies regarding the effect of bone scintigraphy in patients with extremity pain have not been widely conducted. Ultrasound, CT and MRI are widely used imaging modalities for evaluating extremity pain. However, SPECT/CT has an additional role in assessing pain in the extremities.

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.

Evaluation and Diagnosis of Back Pain in Children and Adolescents

Although traditionally it has been accepted that back pain in young children and adolescents most often has an organic etiology, nonorganic back pain in this population is becoming more common. The most common identifiable clinical entities responsible for such pain are spondylolysis, spondylolisthesis, Scheuermann kyphosis, overuse syndromes, disk herniation, apophyseal ring fracture, spondylodiscitis, vertebral osteomyelitis, and neoplasm. Appropriate clinical workup leads to earlier diagnosis and management of back pain and avoids unnecessary cost. Knowledge of the most common diagnoses associated with back pain in children and adolescents and the use of a systematic method to select the appropriate diagnostic tests can help the clinician to minimize costs and maximize the likelihood of making the correct diagnosis and providing appropriate treatment.

Approach to the pediatric athlete with back pain: more than just the pars

Back pain in a pediatric patient can present a worrisome and challenging diagnostic dilemma for any physician. Although most back pain can be attributed to muscle strains and poor mechanics, it is necessary to appreciate the full differential of etiologies causing back pain in the pediatric population. The physician must recognize areas of mechanical weakness in the skeletally immature spine and the sport specific forces that can predispose a patient to injury. A comprehensive history involves determining the onset, chronicity, and location of the pain. A focused physical exam includes a neurological exam as well as provocative testing. The combination of a thorough history and focused physical exam should guide appropriate imaging. Radiographic tests are instrumental in narrowing the differential, making a diagnosis, and uncovering associated pathology. Treatment modalities such as activity modification, heat/cold compresses, and NSAIDs can provide pain relief and allow for effective physical therapy. In most cases nonoperative methods are successful in providing a safe and quick return to activities. Failure of conservative measures requires referral to an orthopedic surgeon, as surgical intervention may be warranted.

Evaluation of a systematic approach to pediatric back pain: the utility of magnetic resonance imaging

BACKGROUND

Several studies have suggested that back pain in the majority of pediatric patients does not have an identifiable cause. Many children undergo extensive diagnostic workup that ultimately results in a nonconfirmative diagnosis. The purpose of this study was to (1) describe the prevalence of back pain seen in a pediatric orthopaedic clinic; (2) evaluate the efficacy of a systematic approach dependent on magnetic resonance imaging (MRI) in the diagnosis of pediatric back pain; and (3) analyze sensitivity, specificity, positive predictive value, and negative predictive value of various clinical signs and symptoms.

METHODS

For a 24-month period, all patients that presented with a chief complaint of back pain were prospectively enrolled in this study and evaluated in a systematic approach which utilized MRI for patients with constant pain, night pain, radicular pain, or abnormal neurological examination after an initial history, physical examination, and negative radiographic examination.

RESULTS

The prevalence of chief complaint of back pain was 8.6% (261/3042 patients). Of the 261 patients, 34% had an identifiable pathology following the systematic approach. In 8.8% of patients, the diagnosis was established with the history, physical examination, and plain radiographs. MRI yielded a definitive diagnosis in another 25% of patients. It is noteworthy that of the 89 patients with a confirmed pathology, 26% were identified with plain radiographs and 74% with MRI.

CONCLUSIONS

A systematic approach to diagnose pediatric back pain demonstrated that 34% of pediatric patients that present to an outpatient orthopaedic clinic complaining of back pain will have identifiable pathology. The diagnostic yield increased from 8.8% with the history, physical examination, and plain radiographs to 22% with the TCN Bone Scan to 36% with the use of the MRI. The clinician should be aware that the presences of lumbar pain or constant pain are red flags for the presence of underlying pathology.

LEVEL OF EVIDENCE

Level III.