Bibliometric evaluation of systematic review and meta analyses published in the top 5 "high-impact" radiology journals.

INTRODUCTION: Meta-analyses provide high-level evidence and understanding their trends may provide understanding of the field as a whole. Bibliometric analysis was undertaken to understand research trends in a particular field or subfield and to assess citation as a measure of impact. METHODS: All journals categorised as "Radiology, Nuclear Medicine & Medical Imaging" under the Web of Science subject category were included. After analyzing impact factors of the journals in up to 2018, the top five journals were identified. The retrieved results were ordered by citation count based on Web of Science and Scopus. Specific parameters regarding the title, journal, publication year, authors, country of origin, institution and university, field of study and funding sources were analyzed. RESULTS: A total of 139 articles were identified. The mean number of citations per article was 25.3 and 22.6 in Scopus and Web of Science respectively, with four articles receiving 100 or more citations. European Radiology had the greatest number of top cited articles (n = 68; 49%). Most number of articles originated from South Korea (n = 60; 43%) and the commonest field of focus with the most common being oncology (n = 51; 27%). CONCLUSION: The top 5 high impact journals published a large number of meta-analysis and systematic reviews. The greatest number of top-cited articles were from South Korea, shifting away from the United States. Large number of studies focused on oncologic imaging, consistent with recent trends towards development of imaging biomarkers and personalized medicine. Author H index did not predict citation number or density.

Relationship between sagittal balance and adjacent segment disease in surgical treatment of degenerative lumbar spine disease: meta-analysis and implications for choice of fusion technique.

STUDY DESIGN: Meta-analysis. OBJECTIVE: To conduct a meta-analysis investigating the relationship between spinopelvic alignment parameters and development of adjacent level disease (ALD) following lumbar fusion for degenerative disease. ALD is a degenerative pathology that develops at mobile segments above or below fused spinal segments. Patient outcomes are worse, and the likelihood of requiring revision surgery is higher in ALD compared to patients without ALD. Spinopelvic sagittal alignment has been found to have a significant effect on outcomes post-fusion; however, studies investigating the relationship between spinopelvic sagittal alignment parameters and ALD in degenerative lumbar disease are limited. METHODS: Six e-databases were searched. Predefined endpoints were extracted and meta-analyzed from the identified studies. RESULTS: There was a significantly larger pre-operative PT in the ALD cohort versus control (WMD 3.99, CI 1.97-6.00, p = 0.0001), a smaller pre-operative SS (WMD - 2.74; CI - 5.14 to 0.34, p = 0.03), and a smaller pre-operative LL (WMD - 4.76; CI - 7.66 to 1.86, p = 0.001). There was a significantly larger pre-operative PI-LL in the ALD cohort (WMD 8.74; CI 3.12-14.37, p = 0.002). There was a significantly larger postoperative PI in the ALD cohort (WMD 2.08; CI 0.26-3.90, p = 0.03) and a larger postoperative PT (WMD 5.23; CI 3.18-7.27, p < 0.00001). CONCLUSION: The sagittal parameters: PT, SS, PI-LL, and LL may predict development of ALD in patients' post-lumbar fusion for degenerative disease. Decision-making aimed at correcting these parameters may decrease risk of developing ALD in this cohort. These slides can be retrieved under Electronic Supplementary Material.