Publication trends in spine research from 2007 to 2016: Comparison of the Orthopaedic Research Society Spine Section and the International Society for the Study of the Lumbar Spine

Muscle-driven forward dynamic active hybrid model of the lumbosacral spine: combined FEM and multibody simulation

Most spine models belong to either the musculoskeletal multibody (MB) or finite element (FE) method. Recently, coupling of MB and FE models has increasingly been used to combine advantages of both methods. Active hybrid FE-MB models, still rarely used in spine research, avoid the interface and convergence problems associated with model coupling. They provide the inherent ability to account for the full interplay of passive and active mechanisms for spinal stability. In this paper, we developed and validated a novel muscle-driven forward dynamic active hybrid FE-MB model of the lumbosacral spine (LSS) in ArtiSynth to simultaneously calculate muscle activation patterns, vertebral movements, and internal mechanical loads. The model consisted of the rigid vertebrae L1-S1 interconnected with hyperelastic fiber-reinforced FE intervertebral discs, ligaments, facet joints, and force actuators representing the muscles. Morphological muscle data were implemented via a semi-automated registration procedure. Four auxiliary bodies were utilized to describe non-linear muscle paths by wrapping and attaching the anterior abdominal muscles. This included an abdominal plate whose kinematics was optimized using motion capture data from upper body movements. Intra-abdominal pressure was calculated from the forces of the abdominal muscles compressing the abdominal cavity. For the muscle-driven approach, forward dynamics assisted data tracking was used to predict muscle activation patterns that generate spinal postures and balance the spine without prescribing accurate spinal kinematics. During calibration, the maximum specific muscle tension and spinal rhythms resulting from the model dynamics were evaluated. To validate the model, load cases were simulated from -10° extension to +30° flexion with weights up to 20 kg in both hands. The biomechanical model responses were compared with in vivo literature data of intradiscal pressures, intra-abdominal pressures, and muscle activities. The results demonstrated high agreement with this data and highlight the advantages of active hybrid modeling for the LSS. Overall, this new self-contained tool provides a robust and efficient estimation of LSS biomechanical responses under in vivo similar loads, for example, to improve pain treatment by spinal stabilization therapies.

Publication rates of abstracts presented across 6 major spine specialty conferences

Background

Although scientific researchers aim to present their projects at academic conferences as a step toward publication, not all projects mature to become a peer-reviewed manuscript. The publication rate of meetings can be utilized to assess the quality of presented research. Our objective was to evaluate the contemporary publication rate of abstracts presented at spine conferences.

Methods

We reviewed annual meeting programs of North American Spine Society (NASS), Scoliosis Research Society (SRS), International Meeting on Advanced Spine Techniques (IMAST), Spine Global Spine Congress (GSC), Lumbar Spine Research Society (LSRS), and Cervical Spine Research Society (CSRS) from 2017 to 2019. Abstracts were identified as published from PubMed and Google search. From published manuscripts, journal name and open access status was collected. Journal impact factors were collected from the 2021 Journal Citation Reports.

Results

A total of 3,091/5,722 (54%) abstracts were published, ranging from 44.5% to 66.3%. Publication rate of posters and podiums ranged from 39.8% to 64.8% and 51.6% to 67.2%, respectively. Podium presentations were more likely to be published than posters (59.6% vs. 47.2%, p<.001). Only NASS (61.4% vs. 61.8%) and LSRS (64.6% vs. 67.2%) demonstrated similar publication rates for posters and podiums. Award nominated abstracts had a significantly higher publication rate (68.0% vs. 53.4%, p<.001). Among journals with an impact factor, the median overall impact factor was 3.27 and was similar between all conferences except GSC, which was slightly lower (2.72 vs. 3.27, p<.001).

Conclusions

Fifty-four percent of abstracts were published with 3 societies (NASS, LSRS, and SRS) having rates of over 60%. Moreover, NASS and LSRS demonstrated high publication rates regardless of presentation type. These numbers are significantly higher than previous reports suggesting that these conferences allow attendees to review high quality evidence that is likely to achieve peer-reviewed publication while obtaining an early look at original research.

Age-based exclusion is common and multifactorial in spinal RCTs: a systematic review and quantitative analysis

Most diseases of the spine disproportionately impact older persons, with the modal (i.e., commonest) patient a female in their 8th decade of life. We examined the corpus of spinal RCTs to determine how many included "average" spine patients. We searched PubMed for randomized clinical trials published in the top 7 spine journals over a period of 5 years from 2016 to 2020 and extracted nominal upper age cut-offs and the distribution of ages actually recruited. We identified 186 trials of 26,238 patients. We found that only 4.8% of trials could be applied to an "average" 75-year-old patient. This age-based exclusion was not dependent on funding source. Age-based exclusion was exacerbated by explicit upper age cut-offs, however, the age-based exclusion went beyond explicit age cut-offs. Only few trials were applicable to older patients even amongst trials with no age cut-off specified. Age-based exclusion from clinical trials starts at late middle age. The mismatch between spinal patient's age seen in clinical practice and spinal patient's age in trials was so severe that over the 5 years (2016-2020) almost no RCT evidence was produced applicable to the "average" aged-patient across the body of literature available. In conclusion, age-based exclusion is ubiquitous, multifactorial, and happens on a supratrial level. Eliminating age-based exclusion involves more than an arbitrary lifting of explicitly stated upper age cut-offs. Instead, recommendations include increasing input from geriatricians and ethics committees, establishing updated or new models of cares, and creating new protocols to facilitate further research.

Asia Now Surpasses Europe in Spine Research Productivity: An Analysis From 1976-2020

STUDY DESIGN

Bibliometric review.

OBJECTIVE

This study aims to understand the worldwide research productivity trends in spine-related research over the past five decades.

SUMMARY OF BACKGROUND DATA

Research productivity in the field of spine surgery has increased tremendously over the past decades. However, knowledge regarding the detailed regional disparity is limited.

METHODS

We evaluated original research articles published in four prestigious journals on spine research (European Spine Journal, Journal of Neurosurgery: Spine, Spine, and The Spine Journal) from 1976 to 2020. For 1 year of each decade, the origin of the first and the senior author was assigned to their region of origin. For the year 2020, a detailed analysis of countries and states of origin was performed, and the number of articles was normalized by registered MDs per country (per 10,000 population).

RESULTS

We included a total of 4436 articles and 8776 authors for analysis. From 1976 to 2020, the percentage of publications originating from North America decreased (77%-38%). In contrast, Asian contributions drastically increased (3%-36%), whereas articles originating from Europe only slightly raised (20%-22%). In 2020, the United States was the most productive country worldwide (34% with most articles from New York (19%), followed by China (16%) and Japan (10%). After normalization to registered MDs (per 10,000 population), the United States proved to have the highest number of articles. Besides this, India now ranked fourth and Egypt eighth in terms of the most productive countries per MDs.

CONCLUSION

North America contributed the largest share of all articles published in the last five decades. Asia, which ranks second in 2020, has overtaken Europe. Normalization to registered MDs can be a helpful tool to reflect a country's research productivity more accurately.Level of Evidence: 3.

Advanced Strategies for the Regeneration of Lumbar Disc Annulus Fibrosus

Damage to the annulus fibrosus (AF), the outer region of the intervertebral disc (IVD), results in an undesirable condition that may accelerate IVD degeneration causing low back pain. Despite intense research interest, attempts to regenerate the IVD have failed so far and no effective strategy has translated into a successful clinical outcome. Of particular significance, the failure of strategies to repair the AF has been a major drawback in the regeneration of IVD and nucleus replacement. It is unlikely to secure regenerative mediators (cells, genes, and biomolecules) and artificial nucleus materials after injection with an unsealed AF, as IVD is exposed to significant load and large deformation during daily activities. The AF defects strongly change the mechanical properties of the IVD and activate catabolic routes that are responsible for accelerating IVD degeneration. Therefore, there is a strong need to develop effective therapeutic strategies to prevent or reconstruct AF damage to support operational IVD regenerative strategies and nucleus replacement. By the way of this review, repair and regenerative strategies for AF reconstruction, their current status, challenges ahead, and future outlooks were discussed.

Statistics for the Practicing Spine Surgeon: Fundamental Measurements

There are vast numbers of evidenced-based clinical trials produced each year, making it increasingly difficult to stay up to date with new treatments and protocols designed to provide the most optimal patient care. A physician's ability to combine existing knowledge with new data is limited by a basic understanding of the background statistics used in these studies. Our goal is to not only define the basic statistics commonly used in clinical trials but to also ensure that practitioners are able to have a working understanding of these statistical measurements to effectively make the most informed and efficacious decisions regarding patient management. On the basis of the recent growth of empirical spine literature, it is becoming more important for spine surgeons to have the basic statistical background necessary to efficiently interpret new data, which may affect clinical decision making regarding patient care.

Authorship and study characteristic trends in spine publications from years 2004 to 2017

Background

The goal of this study was to analyze the trends in authorship and study characteristics in Spine using two overlapping ten-year time periods: 2004-2014 and 2007-2017. To our knowledge, no other literature reports study characteristics and authorship in the same time period for spine that would allow for the assessment of confounding factors of trends.

Methods

Authorship and study characteristic data was collected from all scientific manuscripts published in Spine during the years of 2004, 2007, 2014, and 2017. Basic statistics and Kruskal-Wallis test were used to analyze the data.

Results

We found a significant increase in total number of authors (P<0.0001) without discrepancy of unequivocal increases in author degree type: MD/Equivalent (P≤0.0001), PhD/Doctorate (P=0.0017), Masters (P=0.0015), and Bachelors (P≤0.0001). We observed an increase in industry authorship (P≤0.0001), but without a significant increase in industry funding during the same time span. Increases in administration database studies (P≤0.0001) and economic/value studies (P≤0.0001) were also noted. A significant change in percentage of articles with trauma pathology (decrease, P<0.0001) and deformity (increase, P=0.0002) occurred. The number of multi-institutional studies increased (P≤0.0001), while no change in the number of multi-disciplinary studies.

Conclusions

Increases in author number for spine articles over time are a result of a general increase in authors in all degree types, not just non-doctorate degrees. This may be potentially influenced by the increase in multi-institutional studies. From 2004-2017, higher percentages of articles focus on economics. An increase in industry authorship without a corresponding increase in funding suggests industry's more 'hands-on' approach to publication results from their funded studies.

Statistics for the Practicing Spine Surgeon: Supplementary Data Analysis Measurements

With the rapid rise of clinical spine surgery literature in the last few decades, there is a greater need for practicing spine surgeons to confidently analyze and critique published literature within the field. The conclusions drawn from published studies are often integrated into a physician's clinical decision-making. A strong knowledge in the fundamental statistical measurements used most frequently in spine surgery literature can enhance the ability to properly interpret the meaning of a study's results. However, medical education often lacks the incorporation of clinically relevant statistical analysis. The purpose of this review is to provide an overview of some of the most commonly used statistical measurements in spine surgery, specifically intraclass correlation coefficient, diagnostic testing analyses, Kaplan-Meier curves, hazard ratios, distribution, and variance.

A 14-year literature survey on spine-related clinical research output by orthopedic surgeons from mainland China

BACKGROUND

In recent years, China is increasingly playing an active role in various fields of biomedical research. Many bibliometric studies have provided valuable insights to different fields of clinical studies. However, similar evaluation on spine surgery-related clinical research is still limited. We herein aimed to examine the scientific publications by orthopedic spine surgeons from mainland China within a 14-year period.

METHODS

Articles were identified in PubMed using predetermined query terms. Descriptive statistics were calculated, and T tests, Chi-squared tests, and regression analysis were conducted on the number of publications, impact factors (IFs), citations, region of the study, and associated medical subject headings (MeSHs).

RESULTS

A total of 1498 articles were identified and the annual number of publications, citations, and IFs all increased exponentially. The average IF was significantly higher in 2007 to 2013 than 2000 to 2006. Most publications were from Shanghai and Beijing and the 5 most productive administrative regions generated 70% of all publications. Analysis of associated MeSHs suggested research topics became more heterogeneous over the study period.

CONCLUSION

This was the first comprehensive evaluation on the clinical research output by orthopedic spine surgeons from mainland China. The annual number of publications and citations both increased significantly; however, research was highly concentrated in a handful of administrative regions.

Publication trends in spine research from 2007 to 2016: Comparison of the Orthopaedic Research Society Spine Section and the International Society for the Study of the Lumbar Spine

This study investigated current trends in spine publications of the membership of Orthopaedic Research Society Spine Section (ORS3) and the more global and clinically focused International Society for the Study of the Lumbar Spine (ISSLS). The PubMed database was probed to quantify trends in the overall number of articles published, the number of journals these articles were published in, and the number of active scientists producing new manuscripts. We also evaluated trends in flagship spine journals (Spine, European Spine Journal, and The Spine Journal) and in the Journal of Orthopaedic Research. The total number of active ORS3 and ISSLS authors and articles published have increased over the last 10 years. These articles are being published in hundreds of distinct journals; the number of journals is also increasing. Members of both societies published their work in Spine more than any other journal. Yet, publications in Spine decreased over the last 5 years for both ORS3 and ISSLS members, while those in European Spine Journal, and The Spine Journal remained unchanged. Furthermore, members of both societies have published in Journal of Orthopaedic Research at a consistent level. The increasing number of manuscripts and journals reflects a characteristic intrinsic to science as a whole—the global scientific workforce and output are growing and new journals are being created to accommodate the demand. These data suggest that existing spine journals do not fully serve the diverse publication needs of ORS3 and ISSLS members and highlight an unmet need for consolidating the premiere basic and translational spine research in an open access spine‐specific journal. This analysis was an important part of a decision process by the ORS to introduce JOR Spine.