Foot and ankle surgery is a rapidly evolving field — meaning clinicians must stay abreast of the literature and ready to adapt to new techniques, protocols and technology.

However, for the busy orthopedic surgeon, fishing through the sea of journal publications reporting on various foot and ankle diagnostics, treatments and outcomes can become a time-intensive challenge.

"We know that improving care requires leveraging evidence-based medicine, so clinicians need a quick, simple way of gauging the quality of the evidence in a study," says Dr. Joshua Harris, orthopedic surgeon at Houston Methodist. "Fortunately, measuring this is now both common and standardized, especially in high-impact journals."

Previous studies have looked at the impact that level of evidence (LOE) scoring — one of the most common types of methodological quality assessments — has had on the quality of foot and ankle literature. However, no analysis has been performed in the last decade.

Through an analysis published in JAAOS: Global Research and Reviews, Dr. Harris and his team set out to change that.

"Rather than take a single snapshot of where foot and ankle literature stands today, we analyzed how research quality has shifted over the last 25 years," says Dr. Derek Klavas, orthopedic surgery resident at Houston Methodist and first-author on the study. "While doing so, we also asked how authorship diversity and study type have changed."

How has foot & ankle literature changed over the last 25 years?

Dr. Harris' team analyzed 1,242 articles published between 1994 and 2019 in three high-impact journals — Foot and Ankle International, Journal of Bone and Joint Surgery – American Volume, and American Journal of Sports Medicine (AJSM).

From this, the team uncovered a number of trends in foot and ankle literature over time, including:

• Improvement in the overall level of evidence in foot and ankle studies
• Significant improvement in the number of higher level of evidence studies
• A dramatic increase in the number of studies conducted by authors from two or more countries
• A continuing increase in the proportion of clinical studies, as compared to preclinical ones
• Therapeutic (treatment-focused) studies greatly outnumber prognostic, diagnostic and economic modeling studies
• An increase in the number of studies using national databases to collect patient-reported outcomes data
  
  

"These changes and trends not only reflect the shifts in what we as clinicians are focused on, but it helps us understand where the field has improved and where further growth is needed," adds Dr. Klavas.

Within these findings, Dr. Klavas points to three prevailing themes seen in foot and ankle literature over the last 25 years.

Overall level of evidence has increased, but room for improvement still exists

Since implementing level of evidence scoring, many orthopedic journals have seen increased amounts of higher-evidence articles. The extensive literature analysis from Dr. Harris' team demonstrates an increase in the quality of foot and ankle literature, more specifically, too.

"Over the last 25 years, the number of foot and ankle studies with higher-level evidence increased significantly — from 9% to 22%," says Dr. Klavas.

This is certainly encouraging, but Dr. Klavas points out that, still, the majority of studies have lower-level evidence — indicating room for further improvement.

He cites three potential reasons for the continued predominance of lower-level evidence:

• Foot and ankle procedures are typically elective and treatment plans must often blend the surgeon's recommendations with the patient's preferences
• Conducting randomized trials of foot and ankle surgical procedures is challenging, in part due to patients' preconceived notions of particular procedures based on publicly available literature
• A propensity for busy surgeons to choose retrospective studies over prospective ones
  
  

While the first two reasons are largely out of a surgeon's control, limiting the number of retrospective studies likely isn't the solution to further improving the overall quality of foot and ankle literature.

"Retrospective studies still provide value to the orthopedic field," explains Dr. Harris. "Clinicians simply need to keep the limitations of retrospective study design in mind while evaluating the data."

Rather, Dr. Klavas puts forth an alternative way to increase the amount of higher-level evidence in foot and ankle literature.

"We discovered that an area in which we trail behind, compared to other orthopedic specialties, is in the amount of studies using national databases," says Dr. Klavas. "These registries come with caveats, but they also greatly improve evidence quality simply through the high statistical power associated with this method of measuring patient-reported outcomes."

The foot and ankle field embraces internationality

Like most fields, the number of authors per publication has increased in foot and ankle literature over the years. In the foot and ankle field, specifically, this increase is accompanied by an inclusion of more multi-country studies.

"We identified a striking increase (+28%) in the level of non-U.S. authorship over the last 25 years, with U.S. authorship actually decreasing by around the same amount," says Dr. Klavas. "This speaks to the geographic diversity of authorship in foot and ankle literature, and it's a sign of a clinical community that's committed to collaboration."

Of note, the number of countries represented in foot and ankle literature increased over time as well — with 42 different countries represented between 1994 and 2019. The largest international contributors being the United Kingdom, South Korea, Japan, Germany and Canada.

Interestingly, the team also found that articles with international authorship were slightly less likely to be categorized as having lower-level evidence, as compared to those with solely U.S. authorship.

"This may suggest that continuing to embrace authorship internationality could help reduce the overall amount of lower-level evidence in foot and ankle literature," adds Dr. Klavas.

Both international and U.S. authorship studies maintained similar rates of higher-level evidence studies.

Therapeutic studies dominate the literature, but more emphasis may need to be placed on diagnostic and economic studies

While not the primary goal of the study, the team also classified articles as either preclinical or clinical, with clinical articles being further subclassified as therapeutic, prognostic, diagnostic or economic.

"We wanted to see which types of studies predominate in the literature, since this may help uncover whether more effort needs to be placed toward certain types of studies moving forward," explains Dr. Klavas.

In this 25-year time period, foot and ankle clinical studies consistently outnumbered preclinical ones — with the proportion of clinical studies increasing year over year and, eventually, making up 84% of foot and ankle literature in 2019.

"This tells us that clinical research is prioritized over preclinical research, which may be because laboratory studies are more time and resource intensive than clinical ones. Or, perhaps, this is because journals are placing higher importance on human studies and patient-reported outcomes than in vitro laboratory ones," explains Dr. Klavas.

Of the 985 clinical studies further evaluated, therapeutic studies were the most common — accounting for 65% of the foot and ankle clinical literature. Prognostic studies made up another 26% of the clinical literature, while diagnostic and economic studies trailed behind at 8% and 1%, respectively.

"This reveals an imbalance in the types clinical studies being published," says Dr. Klavas.

While it may be expected for therapeutic studies to predominate the literature, the data certainly still highlights a lack of diagnostic and economic studies, in particular.

"We know that new diagnostic technology and techniques can help bring about treatment advancements, and we also know that, with most foot and ankle surgeries being elective procedures, it's important to understand the economic burden of these procedures," says Dr. Klavas. "It may be that orthopedic clinicians and surgeons need to prioritize these types of studies in the future in order to further advance the field."