Global research trends of platelet-rich plasma (PRP) in orthopedic sports injuries: A bibliometric analysis from 2000 to 2024

Abstract

Background:

A bibliometric and knowledge-map analysis is used to explore platelet-rich plasma (PRP) applications in orthopedic sports injuries. It aimed to summarize global research trends related to clinical trials and provide new insights for researchers in this field.

Methods:

The articles and reviews regarding PRP applications in sports injuries were retrieved from the Web of Science Core Collection (2000–2024). CiteSpace, VOSviewer, HistCite Pro, R-Studio, and other analytical tools were used to conduct the bibliometric analysis and visualization of trends, collaborations, and emerging topics.

Results:

Ten thousand eight hundred thirty-five authors from 3231 institutions published 2601 papers in 802 academic journals in 105 scientific categories. The United States was absolutely in the leading position in this research field. The institution that contributed the most publications was the Harvard University. Nicola Maffulli published the most articles and had the most co-citations. Extensive nodes and links indicate close scientific collaboration among countries, institutions, and authors. The most influential research focused on the fundamental aspects of PRP, particularly its application in regenerative medicine as a nonsurgical intervention for sports injury repair. Diverse sports injury models have been employed to investigate the efficacy of PRP. The latest hotspots and topics included the study of the differentiated efficacy of PRP in sports injuries at different anatomical sites and underlying mechanisms. Temporal keyword clustering indicated an evolution in research focus, transitioning from fundamental studies on muscle and ligament healing to advancements in regenerative therapies. Citation burst analysis identified influential publications and emerging research hotspots.

Conclusion:

This study outlines the knowledge-map of PRP research in sports injury management, which may guide clinicians in selecting evidence-based PRP protocols for specific injury types (e.g., tendon vs cartilage). Future studies on PRP clinical trials should focus on large-scale, long-term randomized controlled trials to evaluate the efficacy and safety of current treatment strategies.

1. Introduction

Orthopedic sports injuries constitute a heterogeneous category of musculoskeletal trauma acquired during athletic activities or exercise regimens. The etiology of these injuries encompasses traumatic incidents, inappropriate equipment utilization, suboptimal training methodologies, inadequate preparatory routines, and repetitive microtrauma to specific anatomical structures. Typically, they involve damage to muscles, tendons, ligaments, and other soft tissues, leading to pain and functional limitations. For the knee joint and other high incidence sites are often accompanied by a longer recovery period and higher treatment costs.^[1] Conventional therapeutic approaches for sports injuries comprise conservative management (rest, physical rehabilitation), pharmacological interventions (corticosteroid injections, nonsteroidal anti-inflammatory drugs, NSAIDs), and surgical procedures. Despite these established treatment modalities, complete tissue regeneration and functional restoration remain challenging, especially in cases involving chronic pathology or complex structural damage such as tendinopathies or ligamentous disruptions.^[2]

Platelet-rich plasma (PRP) has emerged as a promising biological therapeutic modality for enhancing tissue repair and regeneration in sports-related injuries. This autologous blood-derived product contains concentrated platelets that secrete multiple bioactive growth factors, including platelet-derived growth factor, transforming growth factor-β (TGF-β), and vascular endothelial growth factor, which collectively orchestrate the tissue healing cascade.^[3] Clinical applications of PRP have expanded considerably in recent years, supported by accumulating evidence of its therapeutic efficacy in diverse sports-related pathologies, including muscle strains, tendinopathies, ligament injuries, and chondral lesions. Notably, PRP interventions have demonstrated favorable outcomes in specific conditions such as lateral epicondylitis, patellar tendinopathy, and knee osteoarthritis (KOA). Nevertheless, significant heterogeneity in preparation protocols, concentration parameters, activation methods, and administration techniques has generated substantial controversy regarding its clinical utility.^[4] Furthermore, the therapeutic response to PRP exhibits marked variability across different anatomical sites and injury classifications. The absence of standardized treatment algorithms and consensus guidelines continues to impede the widespread integration of PRP into routine clinical practice.

Despite existing limitations, ongoing investigations into PRP applications for both acute and chronic musculoskeletal injuries continue to yield promising therapeutic prospects. Bibliometric analysis has recently emerged as a sophisticated methodological approach for quantitatively evaluating research trajectories, collaborative networks, and evolving knowledge domains across scientific disciplines, particularly within sports medicine. Through systematic interrogation of comprehensive scholarly databases, bibliometric analysis enables multidimensional assessment of PRP-related literature within the sports injury context, elucidating publication patterns, identifying research output, key contributors, and cross-institutional and international collaboration networks. This approach facilitates a deeper understanding of PRP research development, highlights influential studies, and informs future research directions. In this study, an in-depth bibliometric analysis was conducted on PRP research in the field of sports injuries to identify the high-activity research domains, prominent contributors, and emerging thematic clusters, thereby offering valuable insights to inform evidence-based clinical practice.

2. Methods

2.1. Data extraction

The data were retrieved and downloaded from Web of Science Core Collection (WoSCC), a widely recognized and authoritative database for bibliometric analysis, encompassing over 10,000 journals. We set the search formula: TS = (Muscles OR Muscle OR Muscle Tissue OR Muscle Tissues OR “Tissue, Muscle” OR “Tissues, Muscle” OR Tendons OR Tendon OR “Tendons, Para-Articular” OR “Para-Articular Tendon” OR “Para-Articular Tendons” OR “Tendon, Para-Articular” OR “Tendons, Para Articular” OR “Tendons, Paraarticular” OR “Paraarticular Tendon” OR “Paraarticular Tendons” OR Epotenon OR Epotenons OR Endotenon OR Endotenons OR Ligaments OR Ligament OR “Interosseal Ligament” OR “Interosseal Ligaments” OR “Ligament, Interosseal” OR “Interosseous Ligament” OR “Interosseous Ligaments” OR “Ligament, Interosseous”) AND (“platelet rich plasma” OR PRP OR “Plasma, Platelet-Rich” OR “Platelet-Rich Plasma”). The retrieval period was set from 2000 to 2024. The search results were saved as plain text files in the “Full Record and Cited References” format, yielding a final dataset of 2601 bibliographic records. The search was restricted to articles published in English. The literature selection process is illustrated in Figure 1.

Figure 1.

Flowchart of literature retrieval in research. WoSCC = Web of Science Core Collection.

2.2. Data analysis

CiteSpace 6.2.R4 (Drexel University, Philadelphia ), one of the most widely adopted visualization software packages in bibliometric research,^[5] facilitates co-occurrence network analysis, burst detection, and clustering analysis to visualize research trends and collaborations. The co-occurrence network maps scientific partnerships by identifying author, institution, and country relationships, with color-coded nodes and edges indicating the evolution of collaborations over time. The author collaboration networks are visualized using VOSviewer, which has a powerful ability to handle large maps. Burst detection, based on Kleinberg algorithm, tracks citation surges to highlight emerging research topics.^[6] Clustering analysis categorizes publications into concept groups based on titles, abstracts, and keywords, reflecting topic evolution across different periods.^[7]

HistCite Pro 2.1 visualizes citation relationships by highlighting frequently cited publications, enabling rapid identification of key literature. It evaluates articles using local citation score and global citation score, representing citations within the software and the WoSCC database, respectively. In this study, PRP-related articles on sports injuries were imported into HistCite Pro 2.1, with a citation threshold of 30, generating a citation network to pinpoint influential studies.

The alluvial generator illustrates temporal trends in research evolution. CiteSpace was used to generate co-occurrence keyword networks, which were then imported into the alluvial generator (https://www.mapequation.org/apps/AlluvialGenerator.html). Each keyword functions as a node, clustered into modules within time slices. Over time, nodes merge or split, forming new modules, while recent modules emerge from prior node intersections. Donut charts were produced using R 4.2.2 (R Core Team), employing the geom_bar function from the ggplot2 (3.4.4) package.

3. Results

3.1. Historical evolution of PRP literature in sports injuries

A total of 2601 publications related to PRP in sports injuries were retrieved, including 1936 research articles and 665 reviews, in which 10,835 authors and 3231 institutions participating, published in 802 journals in 105 scientific categories (Table 1). Annual research outputs (Fig. 2A) revealed initial publications of 11 and 13 PRP-related sports injury papers in 2000 and 2001, respectively, followed by a 5-year decline indicating limited attention to this field. Subsequently, publication volume increased substantially from 2007 to 2013. Despite minor fluctuations between 2014 and 2018, the overall publication trajectory maintained an upward trend, reaching its apex in 2022. Figure 2B displays the top 20 journals by output, with The American Journal of Sports Medicine leading with 133 publications, followed by Arthroscopy – The Journal of Arthroscopic and Related Surgery (65), and Knee Surgery Sports Traumatology Arthroscopy (55). As illustrated in Figure 3, extensive nodes and links indicate tight scientific collaboration across the dimensions of nations, institutions, and authors. The national collaboration network has 82 nodes and 592 links, with node sizes ranging from the United States to People’s Republic of China, Italy, the United Kingdom, and Spain (Fig. 3A). The United States leads with 871 publications (25.3%), followed by China (n = 357, 10.4%) and Italy (n = 234, 6.8%) (Table S1, Supplemental Digital Content, https://links.lww.com/MD/P817). Figure 3B shows the institutional collaboration network with 534 nodes and 710 links, featuring Harvard University (n = 91), University of London (n = 74), PCSHE (n = 60), and Harvard Medical School (n = 58) (Table S1, Supplemental Digital Content, https://links.lww.com/MD/P817). Institutional collaborations were primarily concentrated within the United States, highlighting the need to strengthen international cooperation and overcome academic barriers.

Table 1.

Publication distribution overview.

Categories	Publication	Articles	Review	Authors	Institutions	Journals	Subject categories
Amount	2601	1936	665	10,835	3231	802	105

Figure 2.

(A) The trend of publication outputs about PRP in sports injuries. (B) The top 20 fruitful journals. Y-axis: publication’s quantity. PRP = platelet-rich plasma.

Figure 3.

The co-occurrence map of countries/regions (A), authors (B), and institutions (C) in PRP-sports injuries research. PRP = platelet-rich plasma.

A coauthorship network based on authors with ≥10 publications was constructed (Fig. 3C) to clearly visualize the most prolific contributors. Each circle represents an author, while the lines between circles indicate collaborative relationships; thicker lines denote stronger collaboration intensity and differentiation. Different colors represent distinct clusters of coauthors. A total of 11 researchers published more than 15 papers. Nicola Maffulli had the highest number of publications (NP = 45) and was also the most co-cited author (NC = 2055), followed by Martha M. Murray (NP = 33, NC = 1965), Isabel Andia (NP = 25, NC = 1086), Augustus D. Mazzocca (NP = 22, NC = 978), and Eduardo Anitua (NP = 21, NC = 907) (Table S2, Supplemental Digital Content, https://links.lww.com/MD/P817).

Figure 3C depicts a complex network of interconnections that demonstrates the extensive scientific collaboration among researchers in the PRP and sports injuries field. Coauthor analysis revealed 6 discrete clusters, each color denoting a specific group of closely collaborating investigators. For instance, intensive collaboration among Nicola Maffulli, Vincenzo Denaro, and Umile Giuseppe Longo formed a cohesive research group within the yellow cluster. Similarly, Martha M. Murray and Braden C. Fleming constituted another group within the light blue cluster. Notably, collaboration was observed among the 5 largest coauthor clusters, highlighting a robust and well-connected collaborative research network.

3.1.1. Research context of PRP studies in sports injuries

The co-citation map (Fig. 4) illustrates the intellectual structure of PRP research in sports injuries over the past 2 decades. The map consists of 1549 nodes and 7213 links, indicating a high degree of interconnection among publications. Larger nodes represent highly cited articles, enabling us not only to visualize the citation network but also to identify the most influential works in this field. In the early period (2000–2010), densely interconnected gray nodes laid the foundational framework for the field. During the mid-period (2011–2017), blue nodes became more dispersed, reflecting the formation of distinct research branches. In the recent period (2018–2024), nodes evolved into tighter clusters, suggesting increasing specialization and focused research efforts. Several key publications stood out due to their high citation frequencies, including works by de Vos RJ (2010), Peerbooms JC (2010), Castricini R (2011), Foster TE (2009), Randelli P (2011), de Mos M (2008), Sanchez M (2007), Rodeo SA (2012), Kon E (2009), and Gosens T (2011), with citation counts of 147, 106, 104, 99, 89, 80, 79, 72, 72, and 70, respectively. These highly cited articles played critical roles in shaping the field of PRP for sports injury treatment. The clustering and evolution of these research groups are further illustrated in the citation timeline visualization. In addition, the citation history graph generated using HistCite Pro 2.1 (Table 2) provides further insights into the development of the field. Table 2 lists the milestone publications, with a notable overlap between the top 10 most co-cited and the top 10 most globally cited references Apart from the top-ranked article, Platelet-rich plasma: from basic science to clinical applications, the remaining highly cited articles appear in both categories, representing the widely recognized theoretical foundations and academic consensus in PRP research for sports injuries. These works serve as pivotal starting points for subsequent studies.

Figure 4.

The citation co-occurrence network. The color bar from left (white) to right (red) indicates the year from 2000 to 2024.

Table 2.

The information of the top 30 literature sorted by LCS score.

NO.	Article information	Journal	LCS	GCS
186	Platelet-rich plasma: from basic science to clinical applications	AM J SPORT MED	252	852
202	Positive effect of an autologous platelet concentrate in lateral epicondylitis in a double-blind randomized controlled trial platelet-rich plasma versus corticosteroid injection with a 1-year follow-up	AM J SPORT MED	196	454
278	Platelet-rich plasma augmentation for arthroscopic rotator cuff repair: a randomized controlled trial	AM J SPORT MED	166	332
310	Platelet rich plasma in arthroscopic rotator cuff repair: a prospective RCT study, 2-year follow-up	J SHOULDER ELB SURG	163	289
57	Autologous preparations rich in growth factors promote proliferation and induce VEGF and HGF production by human tendon cells in culture	J ORTHOP RES	150	357
95	Platelet rich plasma (PRP) enhances anabolic gene expression patterns in flexor digitorum superficialis tendons	J ORTHOP RES	143	302
151	Treatment of tendon and muscle using platelet-rich plasma	CLIN SPORT MED	127	283
167	Platelet-rich plasma: new clinical application: a pilot study for treatment of jumper’s knee	INJURY	121	210
255	Efficacy and safety of corticosteroid injections and other injections for management of tendinopathy: a systematic review of randomized controlled trials	LANCET	119	546
130	Platelet-rich plasma enhances the initial mobilization of circulation-derived cells for tendon healing	J CELL PHYSIOL	111	204
351	Growth factor and catabolic cytokine concentrations are influenced by the cellular composition of platelet-rich plasma	AM J SPORT MED	110	373
172	The biology of platelet-rich plasma and its application in trauma and orthopedic surgery: a review of the literature	J BONE JOINT SURG BR	107	417
207	Effects of platelet-rich plasma on the quality of repair of mechanically induced core lesions in equine superficial digital flexor tendons: a placebo-controlled experimental study	J ORTHOP RES	104	192
660	Platelet-rich plasma as a treatment for patellar tendinopathy: a double-blind, randomized controlled trial	AM J SPORT MED	103	213
150	Platelet-rich therapies in the treatment of orthopaedic sport injuries	SPORTS MED	103	214
85	How can one platelet injection after tendon injury lead to a stronger tendon after 4 weeks? Interplay between early regeneration and mechanical stimulation	ACTA ORTHOP	101	189
91	Collagen-platelet rich plasma hydrogel enhances primary repair of the porcine anterior cruciate ligament	J ORTHOP RES	99	236
431	Platelet-rich plasma: the PAW classification system	ARTHROSCOPY	98	372
651	Efficacy of platelet-rich plasma for chronic tennis elbow: a double-blind, prospective, multicenter, randomized controlled trial of 230 patients	AM J SPORT MED	95	243
165	Use of autologous platelet-rich plasma to treat muscle strain injuries	AM J SPORT MED	92	167
508	Comparison of the therapeutic effects of ultrasound-guided platelet-rich plasma injection and dry needling in rotator cuff disease: a randomized controlled trial	CLIN REHABIL	92	184
232	Use of platelet-rich plasma for the treatment of refractory jumper’s knee	INT ORTHOP	91	264
183	Platelet-rich plasma: current concepts and application in sports medicine	J AM ACAD ORTHOP SUR	91	186
350	Platelet-rich plasma versus autologous whole blood for the treatment of chronic lateral elbow epicondylitis: a randomized controlled clinical trial	AM J SPORT MED	90	225
404	Platelet-rich plasma stimulates cell proliferation and enhances matrix gene expression and synthesis in tenocytes from human rotator cuff tendons with degenerative tears	AM J SPORT MED	88	176
267	Autologous platelets have no effect on the healing of human Achilles tendon ruptures: a randomized single-blind study	AM J SPORT MED	88	153
174	Temporal growth factor release from platelet-rich plasma, trehalose lyophilized platelets, and bone marrow aspirate and their effect on tendon and ligament gene expression	J ORTHOP RES	87	269
1094	The effectiveness of platelet-rich plasma in the treatment of tendinopathy: a meta-analysis of randomized controlled clinical trials	AM J SPORT MED	87	201
349	Does platelet-rich plasma accelerate recovery after rotator cuff repair? A prospective cohort study	AM J SPORT MED	86	151
515	Treatment of lateral epicondylitis with platelet-rich plasma, glucocorticoid, or saline: a randomized, double-blind, placebo-controlled trial	AM J SPORT MED	86	238

GCS = global citation score, LCS = local citation score, NO = the number of the literature in the database import into HistCite Pro 2.1.

3.2. Evolution of the most active research topics

3.2.1. Subject category bursts

From 2000 to 2024, citation bursts were identified in 101 out of 105 related subject categories. In the timeline visualization, blue bars represent the overall period, while red segments denote the duration of a significant citation increase, marking the start and end years. Figure 5 illustrates the top 50 categories with the strongest bursts across chronological periods.

Figure 5.

The top 50 subject categories with the strongest citation bursts. Begin = burst’s beginning year, End = burst’s ending year, Strength = burst’s strength, Year = year of the first occurrence.

The longest-lasting bursts were observed in CARDIAC & CARDIOVASCULAR SYSTEMS, VIROLOGY, and PERIPHERAL VASCULAR DISEASE, spanning from 2001 to 2011, with burst strengths of 5.39, 4.29, and 4.28, respectively. Notably, over time, the spectrum of subject categories experiencing bursts broadened, although their burst durations became shorter than in earlier periods. These included BIOPHYSICS (2000–2009), BIOTECHNOLOGY & APPLIED MICROBIOLOGY (2006–2008), TRANSPLANTATION (2009–2013), MULTIDISCIPLINARY SCIENCES (2013–2014), NANOSCIENCE & NANOTECHNOLOGY (2015–2019), OTORHINOLARYNGOLOGY (2019–2021), and MICROBIOLOGY (2020–2024). This evolving categorical landscape throughout the timeline underscores the field’s increasingly interdisciplinary character. Significantly, in the past 5 years, 20 subject categories have experienced bursts (Table S2, Supplemental Digital Content, https://links.lww.com/MD/P817). The 3 most recent categories exhibiting bursts were MEDICINE, GENERAL & INTERNAL (2022–2024), CHEMISTRY, MULTIDISCIPLINARY (2021–2024), and BIOCHEMISTRY & MOLECULAR BIOLOGY (2022–2024). Unlike earlier high-impact categories such as DENTISTRY, ORAL SURGERY & MEDICINE and CARDIAC & CARDIOVASCULAR SYSTEMS, which entered burst periods shortly after emerging, these recently reemerging categories reflect renewed interest after 2 decades of research (suggesting their potential to become major research focuses in the future).

3.2.2. Keyword bursts

At a more granular level, the burst patterns of keywords reveal the dynamic evolution of research priorities in PRP-related sports injury studies from 2000 to 2024. Keyword bursts refer to the sudden surge in the frequency of specific terms within a short timeframe, indicating a sharp rise in attention to particular topics. These bursts often highlight emerging research hotspots and provide insight into the evolving directions of the field.^[8] From 2000 to 2024, notable shifts in PRP-related keywords were observed, reflecting the appearance of new topics over time (Fig. 6). This temporal transformation not only illustrates changes in research focus across different periods but also offers predictive value for identifying future trends and informing frontier investigations. During the past 25 years, 669 keywords experienced bursts. In the timeline visualization, blue lines represent the entire time span from 2000 to 2024, while red lines indicate the specific duration of each keyword burst. Figure 6 displays the top 50 keywords ranked by burst strength, showing their emergence across various periods.

Figure 6.

The top 50 keywords with the strongest citation bursts. “Begin” and “End” indicate the start and end times of a keyword burst, respectively. “Strength” represents the intensity of the burst, with higher values indicating greater impact. The blue line represents the time span, while the red line indicates the period when the keyword burst occurs.

In the initial phase (2000–2010), significant temporal trajectories were documented across multiple keywords, including growth factor beta, guided tissue regeneration, prion protein, factor beta, scrapie, Creutzfeldt–Jakob disease, aggregation, periodontal ligament cells, and proliferation. Among them, growth factor beta exhibited maximal prominence between 2005 and 2012 with the highest burst strength of 11.72, followed by “guided tissue regeneration” with a burst strength of 10.91. During the intermediate period (2011–2017), notable emerging keywords included marrow stromal cells, randomized controlled trial, growth factors, tendon repair, 2 year follow up, tendinosis, culture, and supraspinatus tendon. Notably, marrow stromal cells peaked between 2009 and 2015 with a burst strength of 10.91. In the contemporary period (2019 to present), particular attention was given to 20 keywords that remain in a burst state through 2024, indicating their potential as future research hotspots. For instance, efficacy showed a burst strength of 13.4 between 2020 and 2024, constituting the highest value during this interval. Pain followed with a strength of 9.72 over the same timeframe. Knee osteoarthritis exhibited a burst from 2022 to 2024 with a strength of 6.17, while rotator cuff tear emerged strongly between 2023 and 2024 with a strength of 5.79 (Table S2, Supplemental Digital Content, https://links.lww.com/MD/P817).

3.2.3. Reference bursts

The article Comparison of surgically repaired Achilles tendon tears using platelet-rich fibrin matrices exhibited the highest citation burst, with its burst period spanning from 2008 to 2012. In this investigation, researchers developed a formulation rich in growth factors through the addition of Ca²⁺ to PRP, subsequently documenting its effectiveness in facilitating expedited tendon repair and functional restoration (Table 3). Between 2011 and 2015, the article Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial experienced the second major citation burst. It was a stratified, block-randomized, double-blind, placebo-controlled trial conducted at a single center (Medical Center Haaglanden, The Hague, Netherlands), which concluded that PRP injections did not provide superior improvements in pain or activity levels compared to placebo (saline) in patients undergoing eccentric exercise therapy for chronic Achilles tendinopathy (AT) (Table 3). The third most prominent citation burst was observed in Treatment of chronic elbow tendinosis with buffered platelet-rich plasma, which attracted considerable attention from 2008 to 2011. This pilot study assessed the efficacy of PRP in patients with lateral epicondylitis of the elbow and found that PRP significantly reduced pain in individuals with chronic elbow tendinosis. Moreover, the longer the follow-up period, the greater the pain relief achieved, leading the authors to recommend PRP as a treatment option before considering surgery (Table 3). From the inception of PRP research to 2024, a total of 54 publications were identified as having experienced significant citation bursts. Table 4 lists the top 20 articles with the highest citation burst strength. Among them, 7 were review articles and 13 were original research articles. These publications typically entered their burst phase either immediately upon publication or within 1 year after release. The review articles provided essential guidance for PRP research in sports injuries, while the original research articles offered critical evidence for its clinical applications. This underscores the importance for researchers in the PRP-sports injury field to pay closer attention to these highly influential publications.

Table 3.

The references with citation bursts at different period.

References	Year	Strength	Begin	End	2004–2024
Sánchez M, 2007, AM J SPORT MED, V35, P245, DOI 10.1177/0363546506294078	2007	37.28	2008	2012	▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂
Mishra A, 2006, AM J SPORT MED, V34, P1774, DOI 10.1177/0363546506288850	2006	33.44	2008	2011	▂▂▂▂▂▂▂▂▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▂
Schnabel LV, 2007, J ORTHOP RES, V25, P230, DOI 10.1002/jor.20278	2007	24.94	2008	2012	▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂
Murray MM, 2007, J ORTHOP RES, V25, P81, DOI 10.1002/jor.20282	2007	18.32	2008	2012	▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂
de Mos M, 2008, AM J SPORT MED, V36, P1171, DOI 10.1177/0363546508314430	2008	30.53	2009	2013	▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂
Kajikawa Y, 2008, J CELL PHYSIOL, V215, P837, DOI 10.1002/jcp.21368	2008	22.08	2009	2013	▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂
Creaney L, 2008, BRIT J SPORT MED, V42, P0, DOI 10.1136/bjsm.2007.040071	2008	18.21	2009	2012	▂▂▂▂▂▂▂▂▂▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂
Foster TE, 2009, AM J SPORT MED, V37, P2259, DOI 10.1177/0363546509349921	2009	32.85	2010	2014	▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂
Kon E, 2009, INJURY, V40, P598, DOI 10.1016/j.injury.2008.11.026	2009	23.82	2010	2014	▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂
Mishra A, 2009, CLIN SPORT MED, V28, P113, DOI 10.1016/j.csm.2008.08.007	2009	21.16	2010	2014	▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂
Sánchez M, 2009, SPORTS MED, V39, P345, DOI 10.2165/00007256-200939050-00002	2009	20.16	2010	2014	▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂
Randelli PS, 2008, DISABIL REHABIL, V30, P1584, DOI 10.1080/09638280801906081	2008	17.32	2010	2013	▂▂▂▂▂▂▂▂▂▂▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂
Alsousou J, 2009, J BONE JOINT SURG BR, V91B, P987, DOI 10.1302/0301-620X.91B8.22546	2009	17.17	2010	2014	▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂
de Vos RJ, 2010, JAMA-J AM MED ASSOC, V303, P144, DOI 10.1001/jama.2009.1986	2010	36.14	2011	2015	▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂
Peerbooms JC, 2010, AM J SPORT MED, V38, P255, DOI 10.1177/0363546509355445	2010	25.28	2011	2015	▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂▂
Randelli P, 2011, J SHOULDER ELB SURG, V20, P518, DOI 10.1016/j.jse.2011.02.008	2011	25.48	2012	2016	▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂
Castricini R, 2011, AM J SPORT MED, V39, P258, DOI 10.1177/0363546510390780	2011	23.5	2012	2016	▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂
Gosens T, 2011, AM J SPORT MED, V39, P1200, DOI 10.1177/0363546510397173	2011	20	2012	2016	▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂▂
Rodeo SA, 2012, AM J SPORT MED, V40, P1234, DOI 10.1177/0363546512442924	2012	22.23	2013	2017	▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂▂▂▂▂▂
Mishra AK, 2014, AM J SPORT MED, V42, P463, DOI 10.1177/0363546513494359	2014	17.5	2014	2019	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▃▂▂▂▂▂
Fitzpatrick J, 2017, AM J SPORT MED, V45, P226, DOI 10.1177/0363546516643716	2017	25.45	2017	2022	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▃▂▂
Boesen AP, 2017, AM J SPORT MED, V45, P2034, DOI 10.1177/0363546517702862	2017	25.93	2018	2022	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▂
Filardo G, 2018, KNEE SURG SPORT TR A, V26, P1984, DOI 10.1007/s00167-016-4261-4	2018	19.23	2018	2024	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▃▃
Krogh TP, 2016, AM J SPORT MED, V44, P1990, DOI 10.1177/0363546516647958	2016	18.96	2018	2021	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▂▂▂
Chen X, 2018, AM J SPORT MED, V46, P2020, DOI 10.1177/0363546517743746	2018	28.56	2019	2024	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▃
Hurley ET, 2019, AM J SPORT MED, V47, P753, DOI 10.1177/0363546517751397	2019	18.73	2019	2024	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▃
Chahla J, 2017, J BONE JOINT SURG AM, V99, P1769, DOI 10.2106/JBJS.16.01374	2017	17.99	2019	2022	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▂▂
Le ADK, 2018, CURR REV MUSCULOSKE, V11, P624, DOI 10.1007/s12178-018-9527-7	2018	19.59	2020	2024	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃
Scott A, 2019, AM J SPORT MED, V47, P1654, DOI 10.1177/0363546519837954	2019	18.29	2020	2024	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃
Everts P, 2020, INT J MOL SCI, V21, P0, DOI 10.3390/ijms21207794	2020	25.13	2022	2024	▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃

Table 4.

The references with citation bursts from beginning to 2024.

Begin	End	Strength	Year	Type	Title
2019	2024	28.56	2018	Article	The efficacy of platelet-rich plasma on tendon and ligament healing: a systematic review and meta-analysis with bias assessment
2022	2024	25.13	2020	Review	Platelet-rich plasma: new performance understandings and therapeutic considerations in 2020
2020	2024	19.59	2018	Review	Current clinical recommendations for use of platelet-rich plasma
2018	2024	19.23	2018	Review	Platelet-rich plasma in tendon-related disorders: results and indications
2019	2024	18.73	2019	Article	The efficacy of platelet-rich plasma and platelet-rich fibrin in arthroscopic rotator cuff repair: a meta-analysis of randomized controlled trials
2020	2024	18.29	2019	Article	Platelet-rich plasma for patellar tendinopathy: a randomized controlled trial of leukocyte-rich PRP or leukocyte-poor PRP versus saline
2022	2024	15.97	2021	Review	Tendinopathy
2019	2024	14.65	2018	Review	Is platelet-rich plasma (PRP) effective in the treatment of acute muscle injuries? A systematic review and meta-analysis
2019	2024	12.13	2018	Article	Intratendinous adipose-derived stromal vascular fraction (SVF) injection provides a safe, efficacious treatment for Achilles tendinopathy: results of a randomized controlled clinical trial at a 6-month follow-up
2019	2024	11.93	2019	Article	Nonsurgical treatments of patellar tendinopathy: multiple injections of platelet-rich plasma are a suitable option: a systematic review and meta-analysis
2020	2024	11.92	2018	Article	Clinical and structural evaluations of rotator cuff repair with and without added platelet-rich plasma at 5-year follow-up: a prospective randomized study
2020	2024	11.44	2019	Article	Comparative effectiveness of injection therapies in rotator cuff tendinopathy: a systematic review, pairwise and network meta-analysis of randomized controlled trials
2021	2024	10.78	2019	Review	Mesenchymal stem cells empowering tendon regenerative therapies
2021	2024	10.78	2019	Article	Sodium hyaluronate and platelet-rich plasma for partial-thickness rotator cuff tears
2021	2024	10.78	2021	Article	Which treatment is most effective for patients with Achilles tendinopathy? A living systematic review with network meta-analysis of 29 randomized controlled trials
2021	2024	10.68	2019	Article	Platelet-rich plasma reduces failure risk for isolated meniscal repairs but provides no benefit for meniscal repairs with anterior cruciate ligament reconstruction
2020	2024	10.49	2019	Article	Efficacy of platelet-rich plasma for the treatment of interstitial supraspinatus tears: a double-blinded, randomized controlled trial
2022	2024	10.03	2021	Article	Effect of platelet-rich plasma injection vs sham injection on tendon dysfunction in patients with chronic midportion Achilles tendinopathy: a randomized clinical trial
2022	2024	9.68	2021	Article	Effect of autologous expanded bone marrow mesenchymal stem cells or leukocyte-poor platelet-rich plasma in chronic patellar tendinopathy (with Gap > 3 mm): preliminary outcomes after 6 months of a double-blind, randomized, prospective study
2019	2024	9.19	2018	Review	A review of platelet-rich plasma: history, biology, mechanism of action, and classification

3.3. Emerging trends and new developments

3.3.1. Temporal evolution of keyword clusters

Keywords demonstrate intricate interconnections, forming networked clusters composed of terms that share similar research themes. Identifying these clusters allows for a clearer depiction of the specialized subfields within PRP research in sports injuries. Over the past 2 decades, the evolution of keyword clusters can be divided into 4 distinct stages, each spanning 6 years. Snapshots of keyword clustering during each stage are illustrated in Figure 7. In the initial stage (2000–2006), 88 publications were analyzed, generating 8 clusters such as #0 smooth muscle contraction, #1 prion protein, and #2 neurodegeneration (Fig. 7A). During the second stage (2007–2012), analysis of 390 publications yielded 7 clusters, including #0 periodontal regeneration, #1 tendinopathy, and #2 ACL (anterior cruciate ligament) (Fig. 7B).

Figure 7.

The keyword clusters snapshots in 4 periods. Different colors represent different clusters. (A) 2000 to 2006, (B) 2007 to 2012, (C) 2013 to 2018, and (D) 2019 to 2024.

In the third stage (2013–2018), 928 publications were examined, resulting in 6 major clusters, such as #0 tissue engineering, #1 rotator cuff repair, and #2 lateral epicondylitis (Fig. 7C). The fourth clustering stage (2019–2024) included 1195 publications and resulted in 8 emerging research clusters that aimed to explore the effects of PRP on improving sports injuries, including those affecting tendons, muscles, and ligaments. Among them, clusters #0 tennis elbow, #1 regenerative medicine, #2 rotator cuff, #4 models, #5 anterior cruciate ligament, and #7 plantar fascia (Fig. 7D) have received increased attention from researchers. Cluster #0 tennis elbow comprised 79 publications focused on the application of PRP in treating lateral epicondylitis. Cluster #1 regenerative medicine included 58 publications that deeply investigated the use of PRP in regenerative treatments for sports injuries. Clusters #2 rotator cuff, #5 anterior cruciate ligament, and #7 plantar fascia accumulated 58, 33, and 7 publications respectively, highlighting the therapeutic potential of PRP in treating injuries at different anatomical sites. Cluster #4 models included 50 studies related to sports injury models. All clustering results in this study showed silhouette values (S-values) >0.6, indicating that the clusters are both effective and convincing. Detailed data from the fourth clustering stage (2019–2024) are presented in Table S3, Supplemental Digital Content, https://links.lww.com/MD/P817, where the representative keywords help identify the core research areas of PRP in sports injuries in recent years. Compared with the first 15 years, basic research on PRP remains a central focus.

3.3.2. Visualization of keyword alluvial flow

As illustrated in Figure 8, relevant keywords can be grouped into distinct research modules. Over time, these keywords may diverge or converge through reorganization, resulting in the formation of new modules. Throughout the past 25 years, certain keywords have demonstrated remarkable vitality, emerging as indicators of novel research trends, whereas others have gradually faded from the historical landscape of the field. Table S4, Supplemental Digital Content, https://links.lww.com/MD/P817 lists the top 5 modules each year based on keyword flow ranking. Notably, in 2024, Module 1, highlighted in red, contains keywords that have either diverged into or converged from this research stream, forming the largest and most enduring research branch, indicating that Module 1 represents the most persistent research focus. Additionally, based on the total keyword flow, the top 6 modules in 2024 were visualized (Fig. 9): Module 1 was named as “magnetic_resonance,” includes 8 keywords such as hip_pathology, hamstring_muscle_injury, and femoroacetabular_impingement (Fig. 9A). This highlights that the evaluation of PRP efficacy often requires magnetic resonance imaging (MRI) guidance or injection under MRI assistance. Module 2, titled “exercise_therapy,” consists of 5 keywords including conservative_treatment, cell_therapy, clinical_outcomes, and shoulder (Fig. 9B), reflecting a trend in integrating PRP with nonsurgical therapeutic strategies. Module 3, labeled “hamstring_injury,” compiles 5 keywords such as elbow, dry_needling, blood, and tendinopathy (Fig. 9C), indicating a focus on PRP applications across different anatomical locations and treatment techniques. Module 4, titled “meta-analysis,” aggregates 3 keywords like cartilage_regeneration and adipose_derived_stem_cells (Fig. 9D), suggesting a growing emphasis on evidence synthesis and biologics in PRP-related studies. Module 5, labeled “integrity,” includes 5 keywords like collagen_implant, clinical_outcomes, and tear (Fig. 9E), pointing to structural and functional restoration outcomes. Module 6, named “disease,” encompasses 6 keywords including concentrated_growth_factor, enhancement, osteoarthritis, and regeneration (Fig. 9F), which may reflect a shift toward PRP-based regenerative medicine in degenerative conditions. These modules likely represent emerging trends in PRP treatment of sports injuries for the next 5 years or longer, offering insight into evolving research priorities and therapeutic innovations.

Figure 8.

The keywords alluvial map 2000 to 2024. X axis: time slice. Y axis: counting of modules. Number: order of modules on each time slice sorted by the number of nodes.

Figure 9.

The keywords of top 5 modules in 2024. (A) Module 1. (B) Module 2. (C) Module 3. (D) Module 4. (E) Module 5. (F) Module 6.

3.3.3. The timeline visualization of references

The timeline map of PRP research in sports injuries consisted of 16 clusters in a given time, with clusters arranged top-down according to size (Fig. 10A). Among them, Classic topics include cluster #0 platelet-rich plasma, #2 sports medicine, #6 bone formation, #7 tendon repair, #8 platelet concentration, and #13 osteogenic differentiation. These may not be the newest topics, but they are intricately linked to other clusters. Clusters #10 cellular prion protein, #11 chronic wasting disease, #12 human platelet shape change, #14 prion peptide fragment, #15 cgmp-independent mechanism, and #16 receptor antagonist irbesartan are relatively outdated topics, with little connection to other clusters and no further development on their timelines.

Figure 10.

The reference clusters map. (A) The citation timeline visualization. (B) The burst citation in #1, #3, #4, #5, and #9. (C) Citation frequency distribution of the burst citation. X-axis: year. Y-axis: cited frequency.

Emerging clusters such as #1 tendinopathy, #3 skeletal muscle, #4 corticosteroid injection, #5 rotator cuff repair, and #9 selective musculoskeletal injury have remained consistently active on the timeline (Fig. 10B), suggesting their imminent emergence as predominant investigative foci. Their sustained presence suggests a growing and continuous interest in these areas within the PRP-sports injury domain. Further details regarding these emerging clusters, including their representative keywords, publication volume, and temporal evolution, can be found in Table S5, Supplemental Digital Content, https://links.lww.com/MD/P817, providing valuable insights for researchers aiming to explore future directions in the field. Additionally, some seminal papers (marked with red circles on large nodes) have played a crucial role in advancing these subfields (Fig. 10B).

Boesen AP (2017, Am J Sports Med), belonging to cluster #1 with the co-occurrence frequency of 61, evaluated the efficacy of eccentric training in combination with high-volume injection (HVI) or PRP injections in outcomes of AT, and found that the combination of HVI or PRP with eccentric training appears to be more efficacious in alleviating pain, enhancing activity levels, and diminishing tendon thickness and intratendinous vascularity in chronic AT than eccentric training alone. In the short term, HVI may outperform PRP in improving the outcomes of chronic AT.

A Hamid MS (2014, Am J Sports Med), belonging to cluster #3 with the co-occurrence frequency of 45, evaluated the effect of a single PRP injection in the treatment of grade 2 hamstring muscle injuries, and found that combining a single autologous PRP injection with a rehabilitation program proved significantly more effective in treating hamstring injuries than the rehabilitation program implemented on its own.

Xiao Chen (2018, Am J Sports Med), belonging to cluster #4 with the co-occurrence frequency of 68, conducted a meta-analysis to evaluate the efficacy of PRP in alleviating pain in patients suffering from tendon and ligament injuries. The analysis revealed that PRP potentially reduces pain specifically associated with lateral epicondylitis and rotator cuff injuries.

Castricini R (2011, Am J Sports Med), belonging to cluster #5, led a randomized controlled trial (RCT) to evaluate the efficacy and safety of augmenting rotator cuff repairs with growth factors. The findings from the study do not endorse the use of autologous platelet-rich fibrin matrix (PRFM) to enhance the healing of small or medium-sized rotator cuff tears during double-row repair.

Connor G Ziegler (2019, Am J Sports Med), belonging to cluster #9, showed that bone marrow concentrate may be more effective in treating osteoarthritis and could serve as an intra-articular biological source to enhance healing during postoperative inflammatory and healing phases. Additionally, PRP may be the optimal choice for increasing vascular distribution and facilitating healing in pathological or injured tissues. We have further analyzed the recent citation distribution of these 5 articles (Fig. 10C), suggesting that they may be frequently referenced again in the coming years.

4. Discussion

4.1. Overview of the historical development of PRP in sports injuries

This study represents the first bibliometric analysis examining PRP in sports injuries over the past 2 decades. The PRP domain remains highly active, characterized by a sharp increase in the number of publications, extensive and close scientific collaborations, and a dense citation network. By analyzing the annual publication trends of PRP research in sports injuries, we can better understand the development trajectory of this field.

According to the WoSCC database, a total of 10,835 authors from 3231 institutions have published 2601 articles related to PRP in sports injuries across 802 academic journals. Although foundational research and preliminary applications of PRP originated in the 1970s, widespread clinical adoption did not materialize until the late 1990s and early 2000s. This delay may be attributed to advancements in PRP preparation methods in the 2000s, which standardized and facilitated accessibility. Since then, the annual publication output on PRP applications in sports injuries has exhibited an overall upward trend. The developmental period spanning 1999 to 2006 represented the nascent phase, with only a few publications. Following a surge in 2009, the annual number of publications began to increase significantly, peaking in 2022, indicating a growing interest and rapid development in PRP research for sports injuries.

The rapid expansion of PRP research can be attributed to several factors: The increasing demand for noninvasive or minimally invasive treatments has driven research into the potential applications of PRP, as it is naturally rich in growth factors that stimulate tissue regeneration, aiding in the repair of damaged cells and tissues, making it a significant contributor to regenerative medicine^[4,9]; Advances in molecular biology, biochemistry, and genetic technologies have facilitated in-depth investigations into the cellular mechanisms of PRP, optimizing treatment strategies and improving efficacy; Continuous improvements in PRP preparation techniques, including automated systems for standardizing PRP concentration and composition, have enhanced treatment reliability and reproducibility; The growing funding for PRP research and the increasing number of clinical trials, along with each successful application in orthopedics, have encouraged researchers from other fields to explore the potential benefits of PRP. These factors suggest that PRP will continue to be a focal point in sports medicine in the future.

Figure 2B presents the top 20 leading journals ranked by publication volume, providing valuable guidance for investigators considering manuscript submission. Notably, 8 of the top 10 journals by publication frequency are classified within the Q1 JCR quartile, indicating substantial engagement from prestigious, high-impact periodicals in PRP-sports injury research. The field exhibits distinctive distribution patterns across national, institutional, and investigator dimensions. Figure 3A illustrates that developed nations constitute 80% of the leading 10 countries in publication productivity, with the United States demonstrating preeminent output. This dominance may be attributed to the high cost of PRP preparation, the prolonged treatment cycle, and the overall expense of the therapy. Additionally, 8 of the top 10 institutions in terms of publication volume are based in the United States, with Harvard University leading with 91 publications. The United States serves as a major collaboration hub, with the top 10 institutions (except for 2 from the United Kingdom) all located in the United States, and most of them are concentrated in higher education institutions. These observations suggest that the United States is the most influential country in PRP-sports injury research, producing significantly more research output than other nations. Meanwhile, close international collaborations (Fig. 3B) are fostering the advancement of this field and enhancing the quality of clinical trials. Nevertheless, the high research and clinical application costs persist as significant barriers, limiting widespread PRP therapeutic adoption. Reducing these costs to make PRP treatment more affordable is a crucial issue to be addressed.

In specialized research domains, high co-occurrence or co-citation frequency among researchers facilitates scholarly collaboration and provides directional guidance. Prominent authors in this field include Nicola Maffulli (45 publications), Martha M. Murray (33), Isabel Andia (25), Augustus D. Mazzocca (22), and Eduardo Anitua (21). Among these investigators, Nicola Maffulli demonstrates the greatest influence, with the highest number of publications and citations. The dense interconnections among the 3 leading authors indicate extensive scientific collaboration. Notably, Johnny Huard and Robert D. Laprade (red cluster) are closely linked to 3 of the top 5 clusters, highlighting their significant contributions as bridges between different research groups.

Co-citation analysis (Fig. 4) reveals the importance and historical trajectory of PRP research in sports injuries. The network comprises 1549 nodes and 7213 links, indicating widespread interconnections among publications. Notably, de Vos RJ (2010) is among the most highly co-cited papers, with 7 of the top 10 most co-cited articles belonging to this period (Table 2), underscoring the critical role of early literature in PRP-sports injury research. The development of later-stage nodes into branches and more tightly clustered groups suggests increasing specialization and differentiation within the field.

In 2010, de Vos RJ et al published the most highly co-cited study in the top medical journal JAMA (IF = 63.1). This study compared PRP injections with placebo (saline injections) in treating chronic midportion AT. Both treatments were combined with an eccentric exercise program. The primary outcome was pain and activity level, assessed using the Victorian Institute of Sport Assessment-Achilles questionnaire at 6, 12, and 24 weeks. The results showed significant improvements in both groups, with the authors attributing the pain and functional improvement primarily to eccentric exercise and placebo effects rather than PRP alone. Despite limitations (such as unknown platelet and growth factor concentrations in the PRP preparation and the absence of a PRP-only control group), the study maintains considerable significance. It challenged the efficacy of PRP for AT, contradicting earlier small-scale studies and laboratory research that suggested PRP could promote tendon healing via growth factor release. Given the widespread clinical application of PRP, this study underscored the necessity of evidence-based treatment and rigorous research before recommending PRP as a standard therapy for tendinopathy.

That same year, Peerbooms JC et al published the second most co-cited study, which compared PRP with corticosteroid injections for chronic lateral epicondylitis. In contrast to de Vos et al, this study demonstrated that PRP provided superior long-term efficacy in treating chronic lateral epicondylitis, reducing pain and improving function through the release of healing and tissue repair growth factors. The study contributed to the recognition of PRP as a promising regenerative treatment for patients unresponsive to conventional therapies.

The third most co-cited publication, by Castricini R et al in 2011, was a RCT evaluating the efficacy of autologous PRFM in augmenting arthroscopic rotator cuff repair. Patients were divided into 2 groups: one undergoing standard arthroscopic repair and the other receiving PRFM-enhanced repair. The study used Constant scores and MRI to assess postoperative improvements and tendon integrity. The findings indicated that PRFM was beneficial for small- and medium-sized tears, but its effectiveness for larger tears remained unclear, discouraging the routine use of PRFM for minor rotator cuff tears. The study spurred further research on PRFM’s potential benefits, particularly in more complex shoulder injuries with different healing dynamics.

The most highly cited article, Platelet-rich plasma: from basic science to clinical applications, offers a critical examination of the scientific foundation and clinical viability of PRP. It provides a comprehensive overview of PRP therapy, exploring its biological mechanisms, preparation techniques, and its applications in sports and orthopedic medicine. While acknowledging PRP’s potential in promoting tendon healing, accelerating ligament and muscle recovery, facilitating bone regeneration, and enhancing cartilage repair, the article raises concerns about the reliability of these conclusions, citing the lack of control groups, insufficient statistical power, and reliance on small case series in many studies. Moreover, the variability in PRP formulations and the absence of standardized protocols contribute to inconsistent clinical outcomes. The findings underscore the importance of evidence-based practice and call for larger, well-designed RCTs to generate high-quality evidence and determine the optimal preparation and application of PRP. Overall, the top 3 most-cited articles focus primarily on clinical trials evaluating the efficacy of PRP in treating sports-related injuries, highlighting the critical need for standardized treatment protocols to ensure both safety and effectiveness. Notably, 3 of these 4 influential papers point to the limitations of PRP as a therapeutic option in sports and orthopedic medicine, often due to the lack of methodological rigor in study design. This aligns with the findings of several high-quality RCTs published in leading journals, which report inconsistent and generally limited benefits of PRP, particularly in the treatment of tendon injuries such as Achilles tendon rupture and tendinopathies.^[10–13]

4.2. Research hotspots and emerging trends

Through in-depth analysis of the 20 most recent burst keywords (2020–2024) (Table S2, Supplemental Digital Content, https://links.lww.com/MD/P817), keyword clustering (Fig. 7, Table S3, Supplemental Digital Content, https://links.lww.com/MD/P817), thematic evolution streams (Figs. 8 and 9), citation bursts (Table 4), and reference timeline mapping (Fig. 10), this study identifies that current PRP research is increasingly centered on the differential therapeutic effects and underlying mechanisms of PRP across various anatomical injury sites. These topics are poised to shape the emerging trajectory of PRP applications in sports injury treatment over the next 5 years and potentially beyond.

4.2.1. Efficacy of PRP in sports injuries at different anatomical sites

The research focus on the efficacy of PRP in sports injuries has persisted from 2014 to 2024, with PRP being the most intensively studied keyword in the past 5 years. This indicates that despite a decade of research, the effectiveness and long-term benefits of PRP remain controversial. Larger-scale and more rigorous clinical trials are required to further assess its efficacy. Such controversy arises not only from the heterogeneity of study designs but also from the complexity introduced by variations in PRP preparation standards, injection protocols, and patient populations. Consequently, in recent years, numerous meta-analyses and systematic reviews have emerged, aiming to integrate global data and provide more reliable evidence-based medical support for the clinical application of PRP.

The differentiation in PRP efficacy is evident across various anatomical sites affected by sports injuries. Log-likelihood ratio clustering analysis identified a total of 29 clusters, with 8 recent clusters (2019–2024) highlighting that fundamental research on PRP remains a key focus. Researchers utilize various sports injury models to investigate PRP’s effects, with particular interest in tendons (including tennis elbow, Achilles tendon, rotator cuff, and patellar tendon), KOA, skeletal muscle, and the anterior cruciate ligament. The increasing body of literature on PRP as a regenerative therapy (nonsurgical treatment) for sports injuries is also reflected in citation trends.

The evaluation of PRP efficacy in various sports injuries heavily relies on MRI-based morphological analyses, such as tendon continuity,^[14] cartilage volume, and synovitis, ^[15] functional imaging, including T2-weighted imaging,^[16–18] angiogenesis, and hemodynamics.^[19] MRI imaging has been widely employed to assess intra-articular injections, including PRP and other agents, providing the most critical noninvasive method for objectively quantifying treatment outcomes.

Tendinopathy: Tendons are fibrous structures arranged in bundles and parallel orientations with limited blood supply, making them difficult to heal once injured. Tendinopathy describes a multifaceted pathological condition involving the tendons, with clinical manifestations such as pain, functional decline, and reduced exercise tolerance. Tendinopathy is not merely an inflammatory response but a complex process involving tendon degeneration, extracellular matrix (ECM) remodeling abnormalities, neovascularization, and chronic overload. The primary characteristics include collagen fiber disorganization, increased matrix degradation, and abnormal biomechanical adaptation,^[20] which hinder the restoration of proper mechanical structure and contribute to a high incidence of re-rupture.^[21]

Common tendon injuries include lateral epicondylitis, patellar tendinitis, rotator cuff injuries, and Achilles tendinitis. In recent years, PRP has been increasingly applied in the treatment of tendinopathy. PRP is a high-concentration platelet solution derived from autologous blood, rich in various growth factors (such as platelet-derived growth factor, TGF-β, and vascular endothelial growth factor), which play a crucial role in cell proliferation, tissue repair, and angiogenesis. Basic research has revealed PRP’s potential in modulating inflammation, promoting cell regeneration, and accelerating wound healing,^[3] with its role in tissue repair continuously being validated. Multiple studies have confirmed that PRP enhances tendon healing and alleviates pain while improving functional recovery to a certain extent,^[22] however, not all tendon injuries or degenerative conditions are suitable for PRP treatment.^[23]

4.2.1.1. Lateral epicondylitis (tennis elbow)

Lateral epicondylitis, commonly known as “tennis elbow,” has been extensively studied in the context of PRP therapy. Most studies report positive outcomes. A multicenter RCT conducted by Mishra et al^[24] involving 230 patients with lateral epicondylitis showed no significant difference in Visual Analog Scale pain scores and Patient-Rated Tennis Elbow Evaluation scores between the PRP injection group and the control group (bupivacaine injection) at 12 weeks. However, by 24 weeks, the PRP group demonstrated significantly superior outcomes compared to the control group. Peerbooms et al^[25] designed a double-blind RCT comparing autologous platelet concentrate (PRP) and corticosteroid injections for treating lateral epicondylitis (tennis elbow) with a 1-year follow-up. Their findings suggest that PRP therapy plays a positive role in the long-term management of tennis elbow. Although corticosteroid injections may provide rapid symptom relief in the short term, PRP demonstrated more sustained and significant improvements in pain relief and functional recovery over time, even as early as 6 months posttreatment.^[26] PRP therapy not only exhibits a high safety profile but also promotes tissue repair and regeneration, leading to long-lasting clinical improvements.^[27] These findings support the use of autologous platelet concentrates as a safe and effective alternative for treating lateral epicondylitis. Future studies should focus on determining the optimal treatment timing, dosage, and ideal PRP concentration.

4.2.1.2. Patellar tendinopathy

Patellar tendinopathy is a common sports-related injury. Traditional management approaches include isometric or eccentric exercises combined with shockwave therapy or even surgical intervention, though with limited success rates. PRP injections appear to benefit patellar tendinopathy, with multiple injections effectively alleviating pain and improving function, and these benefits persisting over longer follow-up periods.^[28] Scott et al^[12] compared leukocyte-rich PRP (LR-PRP), leukocyte-poor PRP (LP-PRP), and a saline control group, finding that both PRP types demonstrated superior pain relief and functional improvements in long-term follow-ups (6–12 months). However, LR-PRP may induce a stronger inflammatory response in the short term. Thus, the choice between LR-PRP or LP-PRP may depend on individual patient conditions. Additionally, in some outcome measures, PRP showed no significant difference from saline, suggesting that its efficacy may vary based on individual differences and PRP type, making it unsuitable for all patients. Clinically, PRP therapy may be more beneficial for tendon injuries caused by activities such as dance and ball sports.

Rodas et al^[17] investigated the effects of bone marrow mesenchymal stem cells (MSCs) and LP-PRP in 20 participants with proximal patellar tendinopathy lesions >3 mm, experiencing pain for more than 4 months (mean: 23.6 months) and unresponsive to nonsurgical treatment. The results demonstrated that both treatments, when combined with rehabilitation, reduced pain and improved activity levels, with bone marrow MSCs-treated participants showing greater tendon structural improvement compared to those treated with LP-PRP. Charousset et al^[29] conducted ultrasound-guided PRP injections (once per week for 3 consecutive weeks) in 28 patients with chronic patellar tendinopathy, resulting in significant symptom and functional improvements, with MRI confirming enhanced tendon structural integrity. A systematic review encompassing 70 studies and 2350 patients concluded that multiple PRP injections serve as an effective nonsurgical treatment for chronic patellar tendinopathy,^[28] with mid-term efficacy surpassing that of shockwave therapy.^[30,31]

4.2.1.3. Rotator cuff injury

The rotator cuff, also known as the “rotator sleeve,” is composed of tendons from the supraspinatus, infraspinatus, teres minor, and subscapularis muscles, forming a connected tendon structure. The application of PRP in rotator cuff injuries has shown mixed results. Some studies suggest that PRP can improve symptoms in patients with partial-thickness rotator cuff tears,^[32] providing longer-lasting pain relief compared to corticosteroids.^[33] Hurley et al^[34] conducted several RCTs and revealed that PRP can alleviate postoperative shoulder pain in the short term, promote functional recovery (e.g., Constant and UCLA scores), and enhance integrity repair, especially in patients with massive tears, potentially promoting better tendon healing. A systematic review encompassing 8 RCTs (556 patients) showed that PRP injection improved the short-term efficacy of arthroscopic full-thickness rotator cuff tear repairs, alleviated pain, enhanced shoulder joint function, and reduced the risk of re-tear, with better results in single-row fixation procedures.^[35] Peng et al^[36] analyzed 10 RCTs (628 patients) and found that PRP in arthroscopic rotator cuff repair significantly reduced the re-tear rate and improved clinical function scores compared to arthroscopic repair alone.

However, most orthopedic RCTs have recorded a lack of beneficial effects, and there is still no conclusive evidence regarding its conservative use in rotator cuff diseases. Malavolta et al^[8] compared 2 groups of patients who underwent conventional repair versus PRP-enhanced repair over a 5-year follow-up period. While some short-term studies suggested that PRP may have potential in promoting healing, the long-term effects were not significant. In terms of structural repair improvements, pain relief, functional recovery, and patient satisfaction, no significant differences were found in the integrity and healing of repaired tissue after 5 years. Some studies even suggested that injecting PRP into the supraspinatus tendon tear could increase adverse events,^[37] as the antiproliferative, antiangiogenesis, and proapoptotic tissue changes may have harmful effects on tendon healing, increasing the likelihood of re-tearing.^[38] Therefore, PRP can be considered as an adjunctive treatment for patients with rotator cuff injuries, but its long-term efficacy needs further investigation.

4.2.1.4. Achilles tendinopathy

Complete Achilles tendon ruptures generally require surgical repair, and even after repair, scar tissue may form. Early studies indicated that PRP can promote cell proliferation, collagen synthesis, and inflammation regulation, reducing pain (e.g., Visual Analog Scale scores), improving function (e.g., athletic performance, daily activity levels), and enhancing imaging indicators (such as changes in Achilles tendon structure and neovascularization).^[23,39] However, recent studies have raised doubts about the effectiveness of PRP treatment. van der Vlist et al^[40] argued that exercise therapy, particularly eccentric training, is the first-line treatment for AT. While methods such as ultrasound shockwave therapy, PRP injections, and combination therapies have shown some effect, current evidence is heterogeneous and limited, making it difficult to determine if PRP is superior to exercise therapy when used alone. In chronic midportion AT, a single PRP injection into the tendon did not alleviate functional impairment after 6 months compared to subcutaneous dry needling.^[41] Boesen et al^[42] conducted a randomized, double-blind, prospective study and found that eccentric exercise combined with high-dose steroid injections was more effective in the short term than eccentric exercise combined with PRP in improving chronic midportion Achilles tendinitis. These findings do not support the routine use of PRP for AT, and treatment decisions should still depend on the disease type. PRP should neither be considered a conservative treatment nor a surgical enhancement. Future research on PRP treatment for Achilles tendinitis will continue to attract attention.

KOA: Recent clinical trials have compared the efficacy and safety of PRP alone versus other treatments, including nonsteroidal anti-inflammatory drugs, hyaluronic acid,^[43,44] corticosteroids, ozone therapy, and physical therapy in patients with KOA. The results consistently show that PRP is more effective in alleviating pain and improving function, with longer-lasting effects and no increased risk of adverse reactions. Some studies suggest that the efficacy of PRP may be related to platelet concentration,^[45] leukocyte concentration, injection frequency and intervals, and disease stage. LR-PRP may enhance the inflammatory response, making it more suitable for chronic tendon injuries. LP-PRP may be more suitable for intra-articular injections (e.g., osteoarthritis) to reduce the inflammatory response, demonstrating better efficacy than hyaluronic acid and corticosteroids, with multiple injections potentially more effective than a single injection.^[46] Several meta-analyses support the routine clinical use of intra-articular PRP injections for KOA treatment, and recent studies further confirm the efficacy and safety of PRP in KOA.^[47–50]

4.2.2. Muscle injury and other repairs

Some studies show that PRP can accelerate the healing of acute muscle injuries, but the evidence remains inconsistent. Grassi et al^[51] summarized data from several RCTs, focusing on recovery time, pain relief, functional improvement, and muscle repair. While some trials suggest that PRP may have potential mechanisms to promote healing, significant variations exist across studies in PRP preparation methods, injection protocols, participant characteristics, and injury types. The overall results indicate that, compared to conventional treatment or control groups, PRP does not show a clear advantage in shortening recovery time or improving clinical outcomes. In the context of anterior cruciate ligament (ACL) reconstruction, Everhart et al^[52] found that PRP significantly reduced the failure risk of isolated meniscus repair surgery (without concurrent ACL reconstruction), but showed no additional benefit when combined with ACL reconstruction during meniscus repair. For ankle ligament injuries, PRP has been shown to effectively relieve pain symptoms and improve ankle joint stability.

4.2.3. Mechanism of PRP in treating sports injuries

PRP supports tissue healing through multiple mechanisms, including cell proliferation, angiogenesis, ECM remodeling, inflammation modulation, antimicrobial effects, and platelet-derived microvesicle repair and regeneration.^[4] PRP stimulates the differentiation of MSCs into various tissue types through the activation of growth factors such as IGF-1, thereby promoting cell growth.^[53] Additionally, PRP improves ECM integrity by promoting collagen production and reducing matrix degradation, which benefits cartilage repair and skin regeneration.^[54] Its immune-modulatory properties stem from interleukins and TGF-β; LR-PRP triggers more inflammation, while pure PRP has anti-inflammatory effects, making it useful for osteoarthritis and tendon injuries.^[55] PRP also contains antimicrobial peptides and leukocytes, giving it antimicrobial properties that help prevent surgical wound infections.^[56] These combined effects make PRP a valuable tool in regenerative medicine. However, the molecular mechanisms are not yet fully understood, and PRP shows varying degrees of efficacy across different studies. Therefore, individualized treatment based on evidence-based medicine should be adopted.

Although research topics related to PRP in the field of sports injuries have evolved over time, recently emerging keywords such as PRP efficacy and mechanisms of action are likely to become future research focal points. Notably, recent citation bursts have also centered around these themes. These findings are further supported by keyword clustering and reference timeline visualizations. The shift in subject category bursts also reflects the increasing interdisciplinary involvement in PRP-related studies. Moreover, keyword timeline analyses reveal that while foundational studies on PRP remain classic topics, keywords such as tennis elbow, regenerative medicine, rotator cuff, sports injury models, and anterior cruciate ligament have emerged as prominent new research modules. Thus, it can be concluded that persistent challenges coexist with emerging themes. In summary, this study provides valuable insights into the developmental trajectory of PRP research in sports injuries and offers new directions for future investigations.

5. Limitations

Firstly, this study is based on bibliometric analysis, and tools such as CiteSpace and VOSviewer cannot fully substitute for systematic literature reviews. Secondly, all data were retrieved exclusively from the WoSCC, which may have led to the omission of relevant studies not indexed in this database. Nevertheless, WoSCC remains the most widely used source for scientometric research and is generally considered representative of the broader scientific landscape. The visualization of citation data provides researchers with a clear and intuitive understanding of research hotspots, developmental trajectories, and emerging trends in the field of PRP for sports injuries.

6. Conclusion

This study presents the first in-depth bibliometric mapping of PRP research in the context of sports injuries, identifying key research hotspots and emerging directions. The findings highlight growing interest in the efficacy and underlying mechanisms of PRP for treating various anatomically localized injuries, including tendinopathy, muscle damage, and KOA (insights that may offer valuable guidance for future clinical applications). Moving forward, large-scale, long-term RCTs are essential to rigorously evaluate the effectiveness and safety of current PRP treatments.

Acknowledgments

We gratefully acknowledge the free use of software tools (CiteSpace, VOSviewer, HistCite Pro, R-Studio, and Excel) which were essential to the completion of this bibliometric analysis.

Author contributions

Conceptualization: Heng Yao, Jiaxin Cai.

Data curation: Jiaxin Cai.

Formal analysis: Heng Yao.

Investigation: Heng Yao, Jiaxin Cai, Xidan Lin, Lisha Cai, Wenqiang Zhou.

Methodology: Heng Yao, Xidan Lin.

Project administration: Wenqiang Zhou.

Supervision: Wenqiang Zhou.

Validation: Heng Yao.

Visualization: Lisha Cai.

Writing – original draft: Heng Yao.

Writing – review & editing: Jiaxin Cai, Wenqiang Zhou.