What Is the Comparative Ability of 18F-FDG PET/CT, 99mTc-MDP Skeletal Scintigraphy, and Whole-body MRI as a Staging Investigation to Detect Skeletal Metastases in Patients with Osteosarcoma and Ewing Sarcoma?

BACKGROUND: Skeletal metastases of bone sarcomas are indicators of poor prognosis. Various imaging modalities are available for their identification, which include bone scan, positron emission tomography/CT scan, MRI, and bone marrow aspiration/biopsy. However, there is considerable ambiguity regarding the best imaging modality to detect skeletal metastases. To date, we are not sure which of these investigations is best for screening of skeletal metastasis. QUESTION/PURPOSE: Which staging investigation-18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT), whole-body MRI, or 99mTc-MDP skeletal scintigraphy-is best in terms of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in detecting skeletal metastases in patients with osteosarcoma and those with Ewing sarcoma? METHODS: A prospective diagnostic study was performed among 54 of a total 66 consecutive osteosarcoma and Ewing sarcoma patients who presented between March 2018 and June 2019. The institutional review board approved the use of all three imaging modalities on each patient recruited for the study. Informed consent was obtained after thoroughly explaining the study to the patient or the patient's parent/guardian. The patients were aged between 4 and 37 years, and their diagnoses were proven by histopathology. All patients underwent 99mTc-MDP skeletal scintigraphy, 18F-FDG PET/CT, and whole-body MRI for the initial staging of skeletal metastases. The number and location of bone and bone marrow lesions diagnosed with each imaging modality were determined and compared with each other. Multidisciplinary team meetings were held to reach a consensus about the total number of metastases present in each patient, and this was considered the gold standard. The sensitivity, specificity, PPV, and NPV of each imaging modality, along with their 95% confidence intervals, were generated by the software Stata SE v 15.1. Six of 24 patients in the osteosarcoma group had skeletal metastases, as did 8 of 30 patients in the Ewing sarcoma group. The median (range) follow-up for the study was 17 months (12 to 27 months). Although seven patients died before completing the minimum follow-up, no patients who survived were lost to follow-up. RESULTS: With the number of patients available, we found no differences in terms of sensitivity, specificity, PPV, and NPV among the three staging investigations in patients with osteosarcoma and in patients with Ewing sarcoma. Sensitivities to detect bone metastases for 18F-FDG PET/CT, whole-body MRI, and 99mTc-MDP skeletal scintigraphy were 100% (6 of 6 [95% CI 54% to 100%]), 83% (5 of 6 [95% CI 36% to 100%]), and 67% (4 of 6 [95% CI 22% to 96%]) and specificities were 100% (18 of 18 [95% CI 82% to 100%]), 94% (17 of 18 [95% CI 73% to 100%]), and 78% (14 of 18 [95% CI 52% to 94%]), respectively, in patients with osteosarcoma. In patients with Ewing sarcoma, sensitivities to detect bone metastases for 18F-FDG PET/CT, whole-body MRI, and 99mTc-MDP skeletal scintigraphy were 88% (7 of 8 [95% CI 47% to 100%]), 88% (7 of 8 [95% CI 47% to 100%]), and 50% (4 of 8 [95% CI 16% to 84%]) and specificities were 100% (22 of 22 [95% CI 85% to 100%]), 95% (21 of 22 [95% CI 77% to 100%]), and 95% (21 of 22 [95% CI 77% to 100%]), respectively. Further, the PPVs for detecting bone metastases for 18F-FDG PET/CT, whole-body MRI, and 99mTc-MDP skeletal scintigraphy were 100% (6 of 6 [95% CI 54% to 100%]), 83% (5 of 6 [95% CI 36% to 100%]), and 50% (4 of 8 [95% CI 16% to 84%]) and the NPVs were 100% (18 of 18 [95% CI 82% to 100%]), 94% (17 of 18 [95% CI 73% to 100%]), and 88% (14 of 16 [95% CI 62% to 98%]), respectively, in patients with osteosarcoma. Similarly, the PPVs for detecting bone metastases for 18F-FDG PET/CT, whole-body MRI, and 99mTc-MDP skeletal scintigraphy were 100% (7 of 7 [95% CI 59% to 100%]), 88% (7 of 8 [95% CI 50% to 98%]), and 80% (4 of 5 [95% CI 28% to 100%]), and the NPVs were 96% (22 of 23 [95% CI 78% to 100%]), 95% (21 of 22 [95% CI 77% to 99%]), and 84% (21 of 25 [95% CI 64% to 96%]), respectively, in patients with Ewing sarcoma. The confidence intervals around these values overlapped with each other, thus indicating no difference between them. CONCLUSION: Based on these results, we could not demonstrate a difference in the sensitivity, specificity, PPV, and NPV between 18F-FDG PET/CT, whole-body MRI, and 99mTc-MDP skeletal scintigraphy for detecting skeletal metastases in patients with osteosarcoma and Ewing sarcoma. For proper prognostication, a thorough metastatic workup is essential, which should include a highly sensitive investigation tool to detect skeletal metastases. However, our study findings suggest that there is no difference between these three imaging tools. Since this is a small group of patients in whom it is difficult to make broad recommendations, these findings may be confirmed by larger studies in the future. LEVEL OF EVIDENCE: Level II, diagnostic study.

A radiological parametric comparison of low-grade lytic spondylolisthesis to degenerative spondylolisthesis - A retrospective approach to establish its dysplastic origin.

Objectives: This study aims to compare low-grade lytic spondylolisthesis (LS) and degenerative spondylolisthesis (DS) radiologically. In addition, it seeks to identify underlying similarities between LS and DS. Methods: This study included patients with low-grade single-level spondylolisthesis at L4-L5 or L5-S1. They were categorized into LS and DS. Radiological features, including pedicle height, width, transverse, and sagittal angle, as well as anterior vertebral heights (AVH) and posterior vertebral heights (PVH), were measured using T1-weighted magnetic resonance imaging. Results: The study involved 88 patients: 46 in the DS group and 42 in the LS group. In the LS group, the AVH was significantly higher than the posterior height at L4 and L5 (L4 PVH/AVH ratio 0.93 in LS vs. 0.96 in DS; L5 PVH/AVH ratio 0.84 in LS vs. 0.92 in DS), and pedicles were more medially oriented (L4: 19.62° in LS vs. 17.7° in DS; L5: 28.92° in LS vs. 26.47° in DS). In addition, at L5, the pedicle height (10.67 mm in LS vs. 11.48 mm in DS) and width (13.56 mm in LS vs. 14.37 mm in DS) were smaller compared to the DS group. Conclusions: Low-grade LS shows distinct radiological vertebral and pedicle anatomy compared to DS. Short and thin pedicles and wedge-shaped vertebrae in LS resemble DS, indicating its dysplastic origin.

Geriatric spine fractures - Demography, changing trends, challenges and special considerations: A narrative review.

The aim of this manuscript was to summarize the demography and changing trends of geriatric spinal injuries and to enumerate the challenges and special considerations in the care of geriatric spinal injuries. PubMed, Scopus and Embase databases were searched for literature on geriatric spine fractures using MeSH terms 'aged', 'aged, 80 and over', 'elderly', 'spinal fracture/epidemiology', spinal fracture/therapy∗' and keywords pertaining to the same. The search results were screened for appropriate articles and reviewed. There is a high community prevalence of elderly vertebral fractures ranging from 18% to as high as 51%. The proportion of older patients among the spinal injured is rising as well. There is a higher chance of missing spinal injuries in the elderly and clinical guidelines may not be applicable to this patient group. Classification and surgical treatment are different from younger adult counterparts as the elderly osteoporotic spine behaves differently biomechanically. There is a high incidence of respiratory complications both for surgically and conservatively managed groups. Older age generally is associated with a higher complication rate including mortality.

Alkaptonuria Presenting With Lumbar Disc Herniation: A Case Report.

Alkaptonuria is a rare autosomal recessive trait. Symptomatic lumbar disc herniation warranting surgical intervention is a rare scenario in alkaptonuria and only a few cases have been described in the literature. We present one such rare case of alkaptonuria in a 31-year-old female presenting with low back pain and left leg radiculopathy not relieved with conservative management. Roentgenograms of the lumbar spine revealed wafer-like disc calcifications and MRI showed a herniated disc at the L4-L5 level with deeply hypointense disc spaces in T2 suggestive of disc calcification and associated modic type 2 changes. During the surgery, the disc material removed was black in color, which raised a clinical suspicion of alkaptonuria. Postoperatively, the patient was re-examined and urine homogentisic acid was found to be raised. This, along with a histopathological examination, was diagnostic of alkaptonuria. The patient had excellent relief of symptoms postoperatively. In conclusion, if a 'black disc' is found during surgery, retrospective analysis and re-examination of patient clinical features and urine examination have to be done to diagnose alkaptonuria. While making a differential diagnosis of degenerative disc disease in patients with a calcified disc seen on radiography, a high index of suspicion for alkaptonuria has to be maintained.

Unmasking the great imitators-noninfectious conditions masquerading as spinal tuberculosis in a developing country: A single-center case series analysis.

Background: The diagnosis of spinal tuberculosis often relies on clinical, radiological, and laboratory findings, particularly in resource-constrained settings. However, numerous noninfectious conditions exhibit similar clinical and radiological features to spinal tuberculosis, leading to potential misdiagnosis in the absence of microbiological or histopathological confirmation. This study aims to present a case series from a developing country, highlighting noninfectious conditions that mimic spinal tuberculosis. Methods: A retrospective analysis was conducted on hospital records and imaging of patients diagnosed with spinal tuberculosis, lacking microbiological or histopathological evidence, and unresponsive to empirical antitubercular treatment. Patients displaying noninfectious conditions resembling spinal tuberculosis upon further investigation were included. Clinical and radiological findings of these patients were thoroughly analyzed. Results: Among a total of 23 patients observed over a 6-year period (2015-2020), various noninfectious conditions were identified as mimickers of spinal tuberculosis. These conditions included vertebral body haemangioma, ankylosing spondylitis (with or without Andersson lesion), rheumatoid pannus, osteoid osteoma, cystic hygroma, multiple myeloma, vertebral metastasis, malignant small round-cell tumor, pancreatic pseudocyst, esophageal duplication cyst, Modic changes in degenerative disc disease, Paget's disease, and psoas hematoma. Conclusion: Noninfectious spinal conditions can masquerade as spinal tuberculosis, underscoring the importance of obtaining a definitive tissue diagnosis before initiating antitubercular treatment. Particular attention should be given to features such as central lesions and the absence of soft tissue involvement in suspected cases of spinal tuberculosis, warranting a careful reconsideration of the diagnosis.

Surgical Management of Paediatric Thoracolumbar Tuberculosis by a Combination of Anterior and Posterior Versus Posterior Only Approach: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic Review and Meta-analysis. OBJECTIVES: This systematic review and meta-analysis is aimed to assess effectiveness, safety, clinical, functional and radiological outcome of either combined anteroposterior or posterior-only approach in the surgical management of active tubercular disease of paediatric thoracolumbar spine. METHODS: A systematic literature search through PubMed, Scopus, Web of Science and Cochrane Library database was performed. Data extraction was undertaken following methodological quality assessment. RESULTS: 9 out of the 182 publications identified, were included for analysis. A total of 247 patients were analysed. Two amongst the 9 studies were retrospective comparative studies evaluating posterior approach with combined anteroposterior approach and were considered for comparative meta-analysis. Blood loss and duration of surgery was significantly higher in the anteroposterior group, as compared to the posterior-only group. There was no significant difference between the 2 groups in terms of post-operative kyphosis angles, final kyphosis angles, number of complications, functional outcome and spinal fusion time. However, all the included studies were non-randomised and retrospective. Only 2 of them had a control group with a high heterogeneity amongst these 2 studies. CONCLUSION: The inference from the studies included in this review suggests that equivalent results can be achieved with posterior-only approach for thoracolumbar tuberculosis in children as compared to anteroposterior approach, with much lower complexity, reduced blood loss and shorter surgical time. However, due to the high risk of bias and considerable heterogeneity among the studies included, we cannot conclude whether one approach is better than the other.

Is 6 Months of Antitubercular Chemotherapy as Effective as More Than 6 Months Regimen in Spinal Tuberculosis? A Systematic Review and Meta-analysis.

Historically, osteoarticular tuberculosis (TB), including spinal TB, was treated with prolonged course of antitubercular therapy (ATT). Due to various challenges, there has been reluctance to explore the use of short-course ATT in spinal TB. However, with the success of short-course ATT being demonstrated in other forms of extrapulmonary TB, the subject is open for debate again. Therefore, we systematically reviewed various published literature to determine whether short-course treatment regimen (6 months) of ATT provides equivalent results in terms of disease healing as long-course treatment regimen (≥9 months) in the management of spinal TB. Five electronic databases (PubMed, MEDLINE, EMBASE, CENTRAL, and Web of Science) and their reference lists were searched to identify relevant randomized controlled trials with at least 1 year of follow-up that compared short-course with standard-course ATT for treatment of spinal TB. The methodological quality of included studies was assessed, and their data were extracted. A meta-analysis was used to calculate pooled effect sizes and 95% confidence interval (CI). The outcome measure was healed status of the disease at the final follow-up. Of 331 publications identified through literature search, eight publications describing six randomized studies were included. Moreover, 375 of 414 patients (90.58%) who received 6 months of ATT had healed status at their final follow-up compared to 404 of 463 patients (87.26%) who received ≥9 months of ATT. Overall, the healed status of spinal TB was equivalent in patients in both groups (pooled relative risk, 0.98; 95% CI, 0.92-1.04; p =0.439). However, there was considerable heterogeneity among the trials (I2=40.8%, p =0.149). The results suggest that the use of short-course (6 months) chemotherapy may be considered for the treatment of spinal TB in view of the similarity in the healing response achieved compared to treatment regimens of longer duration.

Predictors of Operative Duration in Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis: A Retrospective Cohort Study.

BACKGROUND: Accurate prediction of operative duration is necessary for efficient operating room scheduling, minimizing cancellations, shortening waitlists, better risk stratification, and effective preoperative counseling. Prolonged operative duration is also associated with negative patient outcomes. Posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) is typically a lengthy surgical procedure with variable operative duration. The purpose of this study is to identify patient-, procedure-, and surgeon-specific variables that influence the operative duration in PSF for AIS and determine its impact on early postoperative outcomes. METHODS: Hospital records of 150 AIS patients who underwent PSF at a single center were retrospectively reviewed. Various patient-, procedure-, and surgeon-specific variables-deemed to be possibly affecting the operative duration-were analyzed. A multivariate regression model was used to identify independent predictors of operative duration. The association between operative duration and early postoperative outcome measures was determined. RESULTS: The final model obtained from the multivariate regression analysis included the following factors: experience of the chief surgeon (ß = -0.36), Cobb angle of the major structural curve (ß = 0.35), number of screws inserted (ß = 0.28), coronal deformity angular ratio (ß = 0.20), and apical vertebral rotation (ß = -0.21 to 0.03). The model could explain 44% of the variability in the operative duration (R 2 = 0.44). The operative duration had a significant correlation with estimated blood loss, need for perioperative blood transfusion, and length of hospital stay. CONCLUSIONS: A set of variables that predict the variability in operative duration during PSF for AIS was identified, with the experience of the chief surgeon and the severity of the curve being the strongest predictors. CLINICAL RELEVANCE: The results of this study emphasize the need for each hospital and surgical team to identify predictors of operative duration in their setup in order to better anticipate prolonged operative duration.

Protocol for Developing a Femur Osteotomy Model in Wistar Albino Rats.

Fracture healing is a physiological process resulting in the regeneration of bone defects by the coordinated action of osteoblasts and osteoclasts. Osteoanabolic drugs have the potential to augment the repair of fractures but have constraints like high costs or undesirable side effects. The bone healing potential of a drug can initially be determined by in vitro studies, but in vivo studies are needed for the final proof of concept. Our objective was to develop a femur osteotomy rodent model that could help researchers understand the development of callus formation following fracture of the shaft of the femur and that could help establish whether a potential drug has bone healing properties. Adult male Wistar albino rats were used after Institutional Animal Ethics Committee clearance. The rodents were anesthetized, and under aseptic conditions, complete transverse fractures at the middle one-third of the shafts of the femurs were created using open osteotomy. The fractures were reduced and internally fixed using intramedullary K-wires, and secondary fracture healing was allowed to take place. After surgery, intraperitoneal analgesics and antibiotics were given for 5 days. Sequential weekly x-rays assessed callus formation. The rats were sacrificed based on radiologically pre-determined time points, and the development of the fracture callus was analyzed radiologically and using immunohistochemistry.