Outcome measures in clinical ACL studies: an analysis of highly cited level I trials.

PURPOSE: Clinical research in the area of anterior cruciate ligament (ACL) injury has shown substantial growth during the last decade. This was accompanied by the establishment of a wide range of outcome measures used to address the demands of clinical studies. The aim of this study was to evaluate outcome measures reported by highly cited level I trials in ACL research and identify factors influencing citation metrics. METHODS: The database of the Institute for Scientific Information (ISI) was utilized to screen journals under the subject categories "Orthopaedics", "Sports Sciences", "Radiology" and "General medicine" for the 50 most cited level I ACL trials based on predefined inclusion criteria. Metadata, citation metrics and outcome measures were extracted for each article. Frequencies of reported outcome measures were calculated, and a multiple linear regression model applied to identify factors influencing citation metrics. RESULTS: Two independent outcome measures demonstrated an influence on acquisition of citations including: 1-report of the pivot-shift test and 2-inclusion of the Knee Injury and Osteoarthritis Outcome (KOOS) score. Furthermore, highly cited ACL trials frequently reported KT-1000 measures of anterior translation, range of motion (ROM), graft failure, Lysholm, Tegner and subjective International Knee Documentation (IKDC) scores. CONCLUSION: This analysis reflects on the outcome measures utilized in highly cited level I trials impacting the field of ACL research. It also identifies factors likely to influence acquisition of citations. This is of both clinical and academic relevance when choosing appropriate measures for post-operative outcome evaluation after ACL surgery. LEVEL OF EVIDENCE: I.

The hundred most cited publications in orthopaedic hip research - a bibliometric analysis.

BACKGROUND: The aim of this study was to identify the 100 most cited classics in the field of hip research analysing their qualities and characteristics. METHODS: Hip joint related articles were identified and the hundred most cited selected for subsequent analysis of citation count, current citation rate, citation density (citations/article age), authorship, geographic origin institution, and level of evidence (LOE). RESULTS: In a total of 121 journals, 1,311,851 articles were published between 1945 and 2013, of which 1,287 (0.1%) possessed 250 citations or more. Total citations per article for the 100 most-cited ranged from 290 to 3,144 citations.The most common areas of research were degenerative disease and arthroplasty, followed by hip preserving surgery for which the leading authors were William H. Harris and Reinhold Ganz respectively. All articles were published in 8 journals and originated from 9 countries. 10 institutes published 48/100 of the articles. There was a significant negative correlation between both citation rate, citation density and article age. Total citation count was highest for articles published in the decade of 1970. Although 5% (2,103 articles) of hip literature comprised randomised trials (RCTs), only 1 (1%) of the citation classics was an RCT. CONCLUSIONS: The study provides intellectual milestones in hip research, reflecting on the qualities and characteristics of the research. Degenerative hip disease and arthroplasty research take up the greatest proportion of citations, followed by hip preserving research. LOE was low and there was only one RCT amongst the classics, emphasising that high LOE is not a prerequisite for a high citation count.

The hundred most cited articles in bariatric surgery.

BACKGROUND: Many studies quantitatively analyzing scientific papers have appeared in the last 2 years. Citation analysis is a commonly used bibliometric method. In spite of some limitations, it remains a good measure of the impact an article has on a specific field, specialty, or a journal. The aim of this study was to analyze the qualities and characteristics of the 100 most cited articles in the field of bariatric surgery. METHODS: The Thomson Reuters Web of Knowledge was used to list all bariatric surgery-related articles (BSRA) published from 1945 to 2014. The top 100 most cited BSRA in 354 surgical and high impact general journals were selected for further analysis. RESULTS: Most of the articles were published in the 2000s (60%). The top 100 most cited were published in 17 of the 354 journals. Leading countries were USA followed by Canada and Australia. Most of the articles published (76%) were clinical experience articles. The most common level of evidence was IV (42%). CONCLUSIONS: Many of the milestone papers in bariatric surgery have been included in this bibliometric study. A huge increase in research activity during the last decade is clearly visible in the field. It is apparent that the number of citations of an article is not related to its level of evidence; a fact that is increasingly being emphasized in surgical research.

Phosphoglycerate kinase 1 as a promoter of metastasis in colon cancer.

Oxidative stress due to intratumoral hypoxia in solid cancer has been shown to be associated with increased mortality. Phosphoglycerate kinase 1 (PGK1) is an enzyme of the glycolytic pathway, which is regulated by hypoxia-inducible factor-1α (HIF-1α) and has been described for its role in tumor progression and metastasis in several malignancies. We investigated whether the expression of PGK1 varies between metastatic and non-metastatic colon cancer. We compared PGK1 expression in colon cancer patients either with or without metastasis via polymerase chain reaction (PCR) and immunohistochemistry. Microarray analysis was performed to test altered gene expression after PGK1 silencing, using isolates from HCT116 cell lines. PCR results showed an increased expression of PGK1 in colon cancer tissue from metastatic patients in comparison to patients with no metastasis (fold change 2.6, p<0.001). Immunohistochemical staining of PGK1 showed stronger staining in metastatic tissue in comparison to non-metastatic cancer tissue according to a semi-quantitative evaluation. Microarray and subsequent pathway analysis provided 4 genes of interest (CYR61, FOS, JUN and EGR1) used for pathway proposal. The results indicate that increased expression of PGK1 in colon cancer tissue is associated with metastasis. Furthermore, we propose several genes induced by PGK1 that could account for cell migration, mainly EGR1 and CYR61 together with the transcription factors FOS and JUN.