Platelet-rich plasma injections for the treatment of refractory Achilles tendinopathy: results at 4 years

Clinical Applications of PRP: Musculoskeletal Applications, Current Practices and Update

Musculoskeletal tissues are often subjected to deleterious effects stemming from traumatic injuries or degenerative pathologies, which can impede the body's natural repair response. The advent of regenerative medicine has emerged as a promising therapeutic approach in modern patient care. Among the interventions in this cutting-edge field, platelet-rich plasma (PRP) and cell-based therapies, such as mesenchymal stem cells, have garnered significant attention. In this article, we endeavor to provide an overview of the current practices and recent developments in PRP therapy, with a particular emphasis on the clinical applications for musculoskeletal pathologies.

Does additional extracorporeal shock wave therapy improve the effect of isolated percutaneous radiofrequency coblation in patients with insertional Achilles tendinopathy? Study protocol for a randomized controlled clinical trial

BACKGROUND

No conclusive evidence recommends a prior treatment for insertional Achilles tendinopathy (IAT). It is theorized that both percutaneous radiofrequency coblation and extracorporeal shockwave therapy (ESWT) relieve pain within the insertion. However, no clinical evidence shows that either treatment promotes the regeneration of the tendon or if the combination of these 2 interventions offers better function and less pain than one therapy.

METHODS

The study is a randomized, controlled trial with patients allocated in a 1:1 ratio to one of two parallel groups. Patients with insertional Achilles tendinopathy who are not satisfied with the effect of conservative treatment will be screened. A minimum of 38 patients will be enrolled after deciding to participate in the trial on an informed basis. Then the intervention group and the control group perform radial ESWT and sham-ESWT respectively at 6 months after percutaneous radiofrequency coblation. The primary outcome will be the Victorian Institute of Sports Assessment Achilles (VISA-A) Score. Secondary outcome measures will be Foot and Ankle Outcome Score (FAOS) scale, visual analog scale (VAS), Tegner Score, and MRI ultra-short echo time (UTE) T2* value. The assessments will occur in 6 months, 1 year, and 2 years, post-operatively. The differences between the 2 groups will be conducted as intention-to-treat basis.

DISCUSSION

We aim to investigate if radiofrequency coblation associated with ESWT can provide more encouraging imaging findings as well as functional and clinical outcomes regarding the treatment of the IAT comparing to the single radiofrequency coblation treatment.

TRIAL REGISTRATION

ChiCTR1800017898; pre-results. Registered on 20 August 2018.

Application of Orthobiologics in Achilles Tendinopathy: A Review

Orthobiologics are biological materials that are intended for the regeneration of bone, cartilage, and soft tissues. In this review, we discuss the application of orthobiologics in Achilles tendinopathy, more specifically. We explain the concepts and definitions of each orthobiologic and the literature regarding its use in tendon disorders. The biological potential of these materials can be harnessed and administered into injured tissues, particularly in areas where standard healing is disrupted, a typical feature of Achilles tendinopathy. These products contain a wide variety of cell populations, cytokines, and growth factors, which have been shown to modulate many other cells at local and distal sites in the body. Collectively, they can shift the state of escalated inflammation and degeneration to reestablish tissue homeostasis. The typical features of Achilles tendinopathy are failed healing responses, persistent inflammation, and predominant catabolic reactions. Therefore, the application of orthobiologic tools represents a viable solution, considering their demonstrated efficacy, safety, and relatively easy manipulation. Perhaps a synergistic approach regarding the combination of these orthobiologics may promote more significant clinical outcomes rather than individual application. Although numerous optimistic results have been registered in the literature, additional studies and clinical trials are still highly desired to further illuminate the clinical utility and efficacy of these therapeutic strategies in the management of tendinopathies.

ICON 2020-International Scientific Tendinopathy Symposium Consensus: A Systematic Review of Outcome Measures Reported in Clinical Trials of Achilles Tendinopathy

BACKGROUND

Nine core domains for tendinopathy have been identified. For Achilles tendinopathy there is large variation in outcome measures used, and how these fit into the core domains has not been investigated.

OBJECTIVE

To identify all available outcome measures outcome measures used to assess the clinical phenotype of Achilles tendinopathy in prospective studies and to map the outcomes measures into predefined health-related core domains.

DESIGN

Systematic review.

DATA SOURCES

Embase, MEDLINE (Ovid), Web of Science, CINAHL, The Cochrane Library, SPORTDiscus and Google Scholar.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Clinical diagnosis of Achilles tendinopathy, sample size ≥ ten participants, age ≥ 16 years, and the study design was a randomized or non-randomized clinical trial, observational cohort, single-arm intervention, or case series.

RESULTS

9376 studies were initially screened and 307 studies were finally included, totaling 13,248 participants. There were 233 (177 core domain) different outcome measures identified across all domains. For each core domain outcome measures were identified, with a range between 8 and 35 unique outcome measures utilized for each domain. The proportion of studies that included outcomes for predefined core domains ranged from 4% for the psychological factors domain to 72% for the disability domain.

CONCLUSION

233 unique outcome measures for Achilles tendinopathy were identified. Most frequently, outcome measures were used within the disability domain. Outcome measures assessing psychological factors were scarcely used. The next step in developing a core outcome set for Achilles tendinopathy is to engage patients, clinicians and researchers to reach consensus on key outcomes measures.

PROSPERO REGISTRATION

CRD42020156763.

Basic Research on Tendon Repair: Strategies, Evaluation, and Development

Tendon is a fibro-elastic structure that links muscle and bone. Tendon injury can be divided into two types, chronic and acute. Each type of injury or degeneration can cause substantial pain and the loss of tendon function. The natural healing process of tendon injury is complex. According to the anatomical position of tendon tissue, the clinical results are different. The wound healing process includes three overlapping stages: wound healing, proliferation and tissue remodeling. Besides, the healing tendon also faces a high re-tear rate. Faced with the above difficulties, management of tendon injuries remains a clinical problem and needs to be solved urgently. In recent years, there are many new directions and advances in tendon healing. This review introduces tendon injury and sums up the development of tendon healing in recent years, including gene therapy, stem cell therapy, Platelet-rich plasma (PRP) therapy, growth factor and drug therapy and tissue engineering. Although most of these therapies have not yet developed to mature clinical application stage, with the repeated verification by researchers and continuous optimization of curative effect, that day will not be too far away.

The use of PRP in treatment of Achilles Tendinopathy: A systematic review of literature. Study design: Systematic review of literature

BACKGROUND

Chronic Achilles Tendinopathy is a common condition that can be challenging to treat. There are many modalities used as treatment ranging from physiotherapy, injections, shockwave therapy to surgical intervention. Platelet Rich Plasma (PRP) has increased in popularity recently as a treatment option for Achilles Tendinopathy. It contains growth factors that might accelerate healing and speed up the recovery of this condition. Many studies have been conducted in the last few years to assess the effectiveness of this treatment method. However, there was controversy as to whether PRP had a beneficial effect on chronic Achille tendinopathy.

AIM

This systematic review of the literature was conducted to ascertain the efficacy of Platelet Rich Plasma (PRP) as a treatment option in chronic Achilles tendinopathy.

METHODS

PRISMA reporting item for systematic review has been used to conduct the selection, Electronic databases included PubMed, EMBASE, Cochrane collaborate, Google scholar, the web of science and Cochrane Library were searched for all RCT, prospective and retrospective studies conducted between January 2010 to February 2019. The quality of each study was evaluated using the Oxford CEBM tool to assess the articles for validity, relevance, and applicability of the results. A total number of 288 were found, and only 11 met the inclusion criteria.

RESULTS

5 Randomised control trials, 4 prospective and 2 retrospective cohort study were included in this systematic review. A total number of 406 patients were treated for non-insertional Achilles tendinopathy of which 230 patients had PRP local injection under Ultrasound guide.

CONCLUSION

Although many of the retrospective studies suggested an advantage of using PRP, the higher level of evidence studies do not support a significant efficacy. This systematic review showed very promising results from the use of Platelet Rich Plasma demonstrated by a significant improvement in the VAST-A score, but we certainly need decent size randomised control trials to show better and more accurate results.

Factors associated with positive outcomes of platelet-rich plasma therapy in Achilles tendinopathy

BACKGROUND

The efficacy of platelet-rich plasma in the treatment for Achilles tendinopathy is debated. Therefore, it is important to know which factors, related to the subjects and/or the disease, are associated with positive or negative outcomes. Aim of this study was to evaluate in a large cohort of patients with Achilles mid-portion tendinopathy which variables were independently associated with a positive outcome after platelet-rich plasma treatment.

MATERIAL AND METHODS

Eighty-four subjects with Achilles tendinopathy were evaluated by means of VISA-A score and ultrasound and treated with a single platelet-rich plasma injection once a week for 3 weeks. Afterward, a rehabilitation program, based on eccentric training, was implemented. At 3 and 6 months, the relationship between the mean VISA-A score and the following putative predictors was evaluated: sex, age, physical activity, sport, smoking, metabolic risk factors, BMI, symptoms duration, tendon damage, neovessels, adherence to eccentric training. Finally, the percentage of clinically evident positive outcomes (defined as an increase in VISA-A score ≥ 20 points) related to each variable was computed.

RESULTS

At final follow-up, using the General Linear Model for Repeated Measures procedure, male sex (0.02), age ≤ 40 (0.05) and adequate eccentric training (0.02) were found to be independently associated with a significant increase in the mean VISA-A score. Moreover, the clinically evident positive outcomes, as previously defined, were significantly associated with male sex (0.01), age ≤ 40 (0.000), BMI ≤ 25 (0.001), symptoms duration ≤ 12 months (0.02) and good adherence to eccentric training (0.004).

CONCLUSION

Younger age, male sex and good adherence to eccentric training can be considered predictors of better results after platelet-rich plasma therapy in Achilles tendinopathy.

Platelet Concentrates in Musculoskeletal Medicine

Platelet concentrates (PCs), mostly represented by platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) are autologous biological blood-derived products that may combine plasma/platelet-derived bioactive components, together with fibrin-forming protein able to create a natural three-dimensional scaffold. These types of products are safely used in clinical applications due to the autologous-derived source and the minimally invasive application procedure. In this narrative review, we focus on three main topics concerning the use of platelet concentrate for treating musculoskeletal conditions: (a) the different procedures to prepare PCs, (b) the composition of PCs that is related to the type of methodological procedure adopted and (c) the clinical application in musculoskeletal medicine, efficacy and main limits of the different studies.

The evaluation of leukocyte-platelet rich fibrin as an anti-inflammatory autologous biological additive. A novel in vitro study

OBJECTIVES

To investigate the use of leukocyte-platelet rich fibrin on suppressing the porphyromonas gingivalis (PG-LPS)-induced secretion of proinflammatory cytokines. Methods:This quantitative experimental study was conducted at the School and Hospital of Stomatology, Jilin University, Changchun, China, between September 2017 and January 2019. A modified technique was used to obtain human gingival fibroblast cells (HGFCs). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Cell Counting Kit-8 tests were established to determine the proliferation rate. Human gingival fibroblast cells were treated by PG-LPS at different periods and the isolated mRNA was subjected to reverse transcription polymerase chain reaction and real time quantitative polymerase chain reaction. The release of platelet-derived growth factor and transforming-growth factor-β1 at various time intervals was observed. Results: We successfully established a modified technique for the production of HGFCs culture. One µg/mL PG-LPS was the recommended concentration to inhibit fibroblast proliferation. The expression of the pro-inflammatory cytokines messenger ribnucleic acid was notably raised at 3 and 6 hours post-PG-LPS treatment. The cumulative release of growth factors peaked during the first 24 hours and the production continued for 10 days. However, the fibroblast expression of cytokines was significantly suppressed after treatment with leucocyte- and platelet-rich fibrin (L-PRF). Conclusion: This study provided a novel way of obtaining HGFCs and greater understanding of the clinical impacts through the assessment of the anti-inflammatory properties of L-PRF in vitro.

Platelet-Rich Plasma Vs Autologous Blood Vs Corticosteroid Injections in the Treatment of Lateral Epicondylitis: A Systematic Review, Pairwise and Network Meta-Analysis of Randomized Controlled Trials

Objective

To compare the effectiveness of platelet‐rich plasma (PRP), autologous blood (AB), and corticosteroid injections in patients with lateral epicondylitis.

Type of Study

Network meta‐analysis.

Literature Survey

Randomized controlled trials (RCTs) that compared any two forms of injections among PRP, AB, and corticosteroid for the treatment of lateral epicondylitis were searched from inception to 30 November 2018, on PubMed, Embase, and Cochrane library.

Methodology

Two researchers independently selected and assessed the quality of RCTs with the Cochrane Risk of Bias Tool. All relevant data from the included studies were extracted and heterogeneity was checked by Cochran's Q test and inconsistency statistic (I²). Publication bias was evaluated by constructing contour‐enhanced funnel plots. Stata 15 software was applied for pairwise meta‐analysis and network meta‐analysis. To explore the efficacy between different follow‐up periods, we considered the duration within 2 months to be short term, whereas 2 months or more was considered long term.

Synthesis

Twenty RCTs (n = 1271) were included in this network meta‐analysis. According to ranking probabilities, corticosteroid ranked first for visual analog score (VAS) (surface under the cumulative ranking [SUCRA] = 90.7), modified Nirschl score (82.9), maximum grip strength (69.5), modified Mayo score (MMS) (77.9), and Patient‐Related Tennis Elbow Evaluation (PRTEE) score (93.3) for the short‐term period. For the long‐term period, PRP ranked first for VAS (94.3), pressure pain threshold (99.8), Disabilities of Arm Shoulder and Hand (DASH) score (75.2), MMS (88.2), and the PRTEE score (81.8).

Conclusion

PRP was associated with more improvement in pain intensity and function in the long term than were the comparators. However, in the short term, corticosteroids were associated with the most improvement.

Conservative Treatment of Chronic Achilles Tendinopathy: A Systematic Review

Achilles tendinopathy is a common musculoskeletal disorder. Athletes, runners and jumpers, and the sedentary are frequently affected. Numerous are the therapeutic choices to manage these kinds of disorders. The aim of this review is to analyze the available literature to document the up-to-date evidence on conservative management of Achilles tendinopathy. A systematic review of two medical electronic databases was performed by three independent authors, using the following inclusion criteria: conservative treatment consisted of pharmacologic, physical therapy without operative treatment, with more of 6 months symptoms and a minimum average of 6-months follow-up. Studies of any level of evidence, reporting clinical results, and dealing with Achilles tendinopathy and conservative treatment were searched for. A total of n = 1228 articles were found. At the end of the first screening, following the previously described selection criteria, we selected n = 94 articles eligible for full-text reading. Ultimately, after full-text reading and a reference list check, we selected n = 29 articles. Achilles tendinopathy is a frequent musculoskeletal disorder and several conservative treatments have been proposed, but no therapy is universally accepted, except for eccentric exercise training, which is the gold standard and a commonly used protocol.

Stem Cells and Platelet-Rich Plasma Enhance the Healing Process of Tendinitis in Mice

Objective

Achilles tendon pathologies occur frequently and have a significant socioeconomic impact. Currently, there is no evidence on the best treatment for these pathologies. Cell therapy has been studied in several animal models, and encouraging results have been observed with respect to tissue regeneration. This study is aimed at evaluating the functional and histological effects of bone marrow stem cell or platelet-rich plasma implantation compared to eccentric training in the treatment of Achilles tendinopathy in rats.

Methods

Fourty-one male Wistar rats received collagenase injections into their bilateral Achilles tendons (collagenase-induced tendinopathy model). The rats were randomly divided into four groups: stem cells (SC), platelet-rich plasma (PRP), stem cells+platelet-rich plasma (SC+PRP), and control (eccentric training (ET)). After 4 weeks, the Achilles tendons were excised and subjected to biomechanical and histological analyses (Sirius red and hematoxylin-eosin staining).

Results

Biomechanical assessments revealed no differences among the groups in ultimate tensile strength or yield strength of the tendons (p = 0.157), but there were significant differences in the elastic modulus (MPa; p = 0.044) and maximum tensile deformation (p = 0.005). The PRP group showed the greatest maximum deformation, and the SC group showed the highest Young's modulus (elasticity) measurement. In histological analysis (hematoxylin-eosin and Sirius red staining), there were no differences among the groups.

Conclusion

PRP and SC+PRP yielded better biomechanical results than eccentric training, showing that these treatments offer better tend function outcomes. This theoretical rationale for the belief that cell therapies can serve as viable alternatives to current treatments chronic fibrotic opens the door for opportunities to continue this research.

Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part II: treatment options

The treatment of painful chronic tendinopathy is challenging. Multiple non-invasive and tendon-invasive methods are used. When traditional non-invasive treatments fail, the injections of platelet-rich plasma autologous blood or cortisone have become increasingly favored. However, there is little scientific evidence from human studies supporting injection treatment. As the last resort, intra- or peritendinous open or endoscopic surgery are employed even though these also show varying results. This ESSKA basic science committee current concepts review follows the first part on the biology, biomechanics and anatomy of tendinopathies, to provide a comprehensive overview of the latest treatment options for tendinopathy as reported in the literature.

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

PURPOSE

Although platelet-rich plasma (PRP) injection has shown controversial results for the treatment of Achilles tendinopathy, it remains the most used biological treatment. Recent findings seem to demonstrate that the stromal vascular fraction (SVF) within adipose tissue may counteract the impaired tendon homeostasis. The aim of this study was to prospectively compare the efficacy of PRP and SVF injection for the treatment of non-insertional Achilles tendinopathy.

METHODS

Fourty-four patients were recruited in the study; 23 of them were assigned to the PRP group whereas 21 to the SVF group, treated unilaterally or bilaterally for a total of 28 tendons per group. All patients (age 18-55 years) were clinically assessed pre-operatively and at 15, 30, 60, 120 and 180 days from treatment, using the VAS pain scale, the VISA-A, the AOFAS Ankle-Hindfoot Score and the SF-36 form. The patients were also evaluated by ultrasound and magnetic resonance before treatment and after 4 (US only) and 6 months.

RESULTS

Both treatments allowed for a significant improvement with respect to baseline. Comparing the two groups, VAS, AOFAS and VISA-A scored significantly better at 15 and 30 days in the SVF in comparison to PRP group (p < 0.05). At the following time points the scores were not significantly different between the two groups. No correlation has been found between clinical and radiological findings.

CONCLUSIONS

Both PRP and SVF were safe, effective treatments for recalcitrant Achilles tendinopathy. The patients treated with SVF obtained faster results, thus suggesting that such a treatment should be taken into consideration for those patients who require an earlier return to daily activities or sport.

LEVEL OF EVIDENCE

Randomized Controlled Clinical Trial, Level 1.

Comparative Analysis of Different Platelet Lysates and Platelet Rich Preparations to Stimulate Tendon Cell Biology: An In Vitro Study

The poor healing potential of tendons is still a clinical problem, and the use of Platelet Rich Plasma (PRP) was hypothesized to stimulate healing. As the efficacy of PRPs remains unproven, platelet lysate (PL) could be an alternative with its main advantages of storage and characterization before use. Five different blood products were prepared from 16 male donors: human serum, two PRPs (Arthrex, (PRP-ACP); RegenLab (PRP-BCT)), platelet concentrate (apheresis, PC), and PL (freezing-thawing destruction of PC). Additionally, ten commercial allogenic PLs (AlloPL) from pooled donors were tested. The highest concentration of most growth factors was found in AlloPL, whereas the release of growth factors lasted longer in the other products. PRP-ACP, PRP-BCT, and PC significantly increased cell viability of human tenocyte-like cells, whereas PC and AlloPL increased Col1A1 expression and PRP-BCT increased Col3A1 expression. MMP-1, IL-1β, and HGF expression was significantly increased and Scleraxis expression decreased by most blood products. COX1 expression significantly decreased by PC and AlloPL. No clear positive effects on tendon cell biology could be shown, which might partially explain the weak outcome results in clinical practice. Pooled PL seemed to have the most beneficial effects and might be the future in using blood products for tendon tissue regeneration.

Platelet-Rich Plasma Injections as a Treatment for Refractory Patellar Tendinosis: A Meta-Analysis of Randomised Trials

Purpose

Patellar tendinosis (PT) is a common condition amongst athletes. In this study, we perform a meta-analysis on randomised controlled trials (RCTs) to evaluate the use of platelet-rich plasma (PRP) for refractory PT.

Methods

A literature search was undertaken in various databases from their year of inception to October 2015. The primary outcome measure was the Victorian Institute of Sports Assessment-Patella (VISA-P) score.

Results

We identified 2 RCTs comparing PRP injections to alternative treatment options (extracorporeal shockwave therapy [ESWT] and dry needling of the tendon). Meta-analysis showed no significant difference in mean VISA-P scores between PRP injection and control at early assessment (2 or 3 months; estimated difference in means, 11.9; standard error [SE], 7.4; 95% confidence interval [CI], -2.7 to 26.4; p=0.109). However, PRP was statistically better than control with regards to VISA-P scores at longer follow-up (6 months or longer; estimated difference in means, 12.7; SE, 4.4; 95% CI, 4.1 to 21.3; p=0.004).

Conclusions

There is a paucity of RCTs evaluating the role of PRP in PT. Our results suggest that, based on limited evidence, PRP is superior over other established non-surgical treatments (dry needling and ESWT) for refractory PT. Larger RCTs may allow better characterisation of the role of PRP in this condition.

Platelet-Rich Plasma as an Autologous and Proangiogenic Cell Delivery System

Angiogenesis is a key factor in early stages of wound healing and is crucial for the repair of vascularized tissues such as the bone. However, supporting timely revascularization of the defect site still presents a clinical challenge. Tissue engineering approaches delivering endothelial cells or prevascularized constructs may overcome this problem. In the current study, we investigated platelet-rich plasma (PRP) gels as autologous, injectable cell delivery systems for prevascularized constructs. PRP was produced from human thrombocyte concentrates. GFP-expressing human umbilical vein endothelial cells (HUVECs) and human bone marrow-derived mesenchymal stem cells (MSCs) were encapsulated in PRP gels in different proportions. The formation of cellular networks was assessed over 14 days by time-lapse microscopy, gene expression analysis, and immunohistology. PRP gels presented a favorable environment for the formation of a three-dimensional (3D) cellular network. The formation of these networks was apparent as early as 3 days after seeding. Networks increased in complexity and branching over time but were only stable in HUVEC-MSC cocultures. The high cell viability together with the 3D capillary-like networks observed at early time points suggests that PRP can be used as an autologous and proangiogenic cell delivery system for the repair of vascularized tissues such as the bone.

The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses

Objectives

After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP).

Methods

Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing.

Results

Histological analysis showed well organised arrangement of collagen fibres and proteoglycan formation in the wounded ATEs in the KGN-PRP group. Furthermore, immunohistochemical analysis revealed fibrocartilage formation in the KGN-PRP-treated ATEs, evidenced by the presence of both collagen I and II in the healed ATE. Larger positively stained collagen III areas were found in both PRP and saline groups than those in the KGN-PRP group. Chondrocyte-related genes, SOX9 and collagen II, and tenocyte-related genes, collagen I and scleraxis (SCX), were also upregulated by KGN-PRP. Moreover, mechanical testing results showed higher ultimate tensile strength in the KGN-PRP group than in the saline control group. In contrast, PRP treatment appeared to have healed the injured ATE but induced no apparent formation of fibrocartilage. The saline-treated group showed poor healing without fibrocartilage tissue formation in the ATEs.

Conclusions

Our results show that injection of KGN-PRP induces fibrocartilage formation in the wounded rat ATEs. Hence, KGN-PRP may be a clinically relevant, biological approach to regenerate injured enthesis effectively.

Cite this article: J. Zhang, T. Yuan, N. Zheng, Y. Zhou, M. V. Hogan, J. H-C. Wang. The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses. Bone Joint Res 2017;6:231–244. DOI: 10.1302/2046-3758.64.BJR-2017-0268.R1.

Long-Term Outcome and Factors Affecting Prognosis of Extracorporeal Shockwave Therapy for Chronic Refractory Achilles Tendinopathy

Objective

To investigate the factors affecting prognosis of extracorporeal shockwave therapy (ESWT) for chronic refractory Achilles tendinopathy (AT).

Methods

Thirty-six patients (48 consecutive feet) with chronic AT (>6 months) and who underwent ESWT for ‘poor’ or ‘fair’ grade in Roles-Maudsley Score (RMS) after unsuccessful conservative treatment were included in the present study. A maximum of 12 sessions of ESWT were conducted until treatment success: RMS reached ‘good’ or ‘excellent’. Termination of ESWT for no response, or ‘poor’ or ‘fair’ grade was regarded as treatment failure. Immediate outcome, long-term outcome (telephone interview after mean 26 months), and factors affecting treatment success were analyzed.

Results

Numeric Rating Scale was significantly decreased at immediate and long-term follow-up. Success rate was 71.1% and 90.3%, respectively. Univariate logistic regression identified that immediate treatment success was associated with retrocalcaneal enthesophyte on X-ray (odds ratio [OR], 0.06; 95% confidence interval [CI], 0.01–0.28), pretreatment abnormal ultrasonography echogenicity within Achilles tendon (OR, 18.89; 95% CI, 2.08–171.96), mean duration of ‘post-treatment soreness’ (OR, 0.55; 95% CI, 0.33–0.94), and duration of ‘post-treatment soreness after first ESWT’ (OR, 0.06; 95% CI, 0.01–0.34). The duration of ‘post-treatment soreness after first ESWT’ was found to be the only factor associated with long-term success (OR, 0.32; 95% CI, 0.10–0.99).

Conclusion

ESWT appears to be effective in achieving long-term success in chronic refractory AT. Immediate success was associated with absence of retrocalcaneal enthesophyte on X-ray, presence of pretreatment abnormal ultrasonography echogenicity, shorter mean duration of ‘post-treatment soreness’, and shorter duration of ‘post-treatment soreness after first ESWT’. The shorter duration of ‘post-treatment soreness after first ESWT’ was identified as the only positive prognostic parameter in achieving long-term success.

Use of Saline as a Placebo in Intra-articular Injections in Osteoarthritis: Potential Contributions to Nociceptive Pain Relief

Background:

Osteoarthritis of the knee (OAK) is a severe debilitating condition characterized by joint pain, stiffness, and resultant limited mobility. In recent years, intra-articular (IA) injections have been used to relieve symptoms and have succeeded to varying degrees either with sodium hyaluronate preparations or with a biologic.

Objective:

The objective of this review is to evaluate multiple studies that demonstrate some relief from the symptoms of OAK in the saline arm of various clinical trials.

Method:

A thorough literature search (PubMed) was performed assessing the pain efficacy of various compounds compared to saline injections in clinical trials. A total of 73 studies were identified in the literature search including a total of 5,816 patients. These clinical trials all involved the IA injection of a viscosupplement (hyaluronate, platelet rich plasma (PRP), etc.) or a biologic (the low molecular weight fraction (< 5kDa) of human serum albumin (LMWF-5A)). For all of these studies, the control arm was injection of sterile physiological saline that approximates the salt concentration and total solute concentration of blood and most tissues.

Results:

Based on our review of the current literature, the tested compounds performed with mixed results when compared to saline injections. Moreover, OAK is a variable disease, with severity measured on the Kellgren and Lawrence (KL) scale where various hyaluronate preparations have a therapeutic effect mostly on KL 2-3 patients while a biologic works best on KL 3-4 patients.

Conclusion:

Since the effect of saline injection is always greater than no treatment, the evaluations of these treatments can be confounded in clinical trials. Therefore, the question of whether there are known therapeutic effects of saline injections might explain these results.

Achilles Tendinopathy: Current Concepts about the Basic Science and Clinical Treatments

Achilles tendinopathy is one of the most frequently ankle and foot overuse injuries, which is a clinical syndrome characterized by the combination of pain, swelling, and impaired performance. The two main categories of Achilles tendinopathy are classified according to anatomical location and broadly include insertional and noninsertional tendinopathy. The etiology of Achilles tendinopathy is multifactorial including both intrinsic and extrinsic factors. Failed healing response and degenerative changes were found in the tendon. The failed healing response includes three different and continuous stages (reactive tendinopathy, tendon disrepair, and degenerative tendinopathy). The histological studies have demonstrated an increased number of tenocytes and concentration of glycosaminoglycans in the ground substance, disorganization and fragmentation of the collagen, and neovascularization. There are variable conservative and surgical treatment options for Achilles tendinopathy. However, there has not been a gold standard of these treatments because of the controversial clinical results between various studies. In the future, new level I researches will be needed to prove the effect of these treatment options.

Efficacy of autologous leukocyte-reduced platelet-rich plasma therapy for patellar tendinopathy in a rat treadmill model

BACKGROUND

An autologous platelet-rich plasma (PRP) therapy has currently been applied for the tendinopathy; however, its efficacy and an optimal platelets concentration in PRP were uncertain. We analyzed them in an animal model prepared using a repetitive running exercise.

METHODS

We made the tendinopathy rat model of patellar tendon using a rodent treadmill machine. Rats with tendinopathy were injected with leukocyte-reduced PRP at the platelets concentration of 1.0×10⁶/μL (P10 group), PRP at the platelets concentration of 5.0×10⁵/μL (P5 group) or normal saline (control group) into the space between the patellar tendon and the fat pad bilaterally or were multiply dry-needled at the tibial insertion site (MN group) at once. To assess the pain-reliving effect, the spontaneous locomotor activities at night (12 h) were measured every day. Histological sections of the patellar tendon stained with hematoxylineosin or prepared by TdT-mediated dUTP nick end labeling were microscopically analyzed.

RESULTS

The numbers of spontaneous locomotor activities in the P10 group were significantly larger than those in the P5, MN or control groups and they recovered up to a healthy level. On histologic examinations, the numbers of microtears, laminations, or apoptotic cells in the patellar tendons in the P10 or P5 groups were significantly lower than those in the MN or control groups, although no significant differences were observed between the P10 and P5 groups.

CONCLUSIONS

The injections of an autologous leukocyte-reduced PRP were effective for pain relief and for partial restoration of the patellar tendon in the tendinopathy rat model. The injections of a PRP at the platelets concentration of 1.0×10⁶/μL completely relieved the pain and were more effective than those at the platelets concentration of 5.0×10⁵/μL whereas there was no difference for the effect of histological restoration or apoptosis inhibition between them.

Effect of intralesional platelet-rich plasma (PRP) treatment on clinical and ultrasonographic parameters in equine naturally occurring superficial digital flexor tendinopathies - a randomized prospective controlled clinical trial

Background

Regenerative and anti-inflammatory effects on tendinopathies have been attributed to blood-derived biologicals. To date the evidence for the efficacy of autologous platelet-rich plasma (PRP) treatment of naturally occurring equine tendinopathies is limited. The purpose of this placebo-controlled clinical trial was to describe the effect of a single treatment of equine superficial digital flexor tendon (SDFT) disease with PRP on clinical and ultrasonographic parameters. Twenty horses with naturally occurring tendinopathies of forelimb SDFTs were randomly assigned to the PRP-treated group (n = 10) or control group (n = 10) after clinical and ultrasonographic examination. The SDFTs received an intralesional treatment with autologous PRP or were injected with saline, respectively (day 0). All horses participated in a standardized exercise programme and were re-examined clinically, with B-mode ultrasonography (5 times at regular intervals) and ultrasound tissue characterization (week 12 and 24 after treatment) until week 24. Long-term performance was estimated via telephone inquiry.

Results

Compared to day 0, lameness decreased significantly by week 8 after treatment with PRP and by week 12 in the control group. Ultrasonographically there was no difference in the summarized cross sectional area between the groups at any time point. Ultrasound tissue characterization showed that echo types representing disorganized matrix decreased significantly throughout the observation period in the PRP-treated group. Echo type II, representing discontinuous fascicles, not yet aligned into lines of stress was significantly higher 24 weeks after PRP treatment. Eighty percent of the PRP treated horses reached their previous or a higher level of performance after 12 months compared to 50 % in the CG. After 24 months these proportions were 60 % and 50 %, respectively.

Conclusions

A single intralesional treatment with PRP up to 8 weeks after onset of clinical signs of tendinopathy contributes to an earlier reduction of lameness compared to saline treatment and to an advanced organization of repair tissue as the fibrillar matrix is getting organized into fascicles while remodelling continues. Long term, PRP treatment has the potential to increase the number of horses reaching their previous level of performance. Earlier treatment of tendinopathy with PRP should be considered to enhance these effects.

Is there a treatment protocol in which platelet-rich plasma is effective?

AIM

We aimed to reveal whether there are prospective suggestions for effective and standard platelet-rich plasma applications.

METHODS

We searched for clinical trials and traced all the references of incorporated documents.

RESULTS

In literature, there was no study indicating which disease is treated by which mechanism of action, how much dose and content are prepared and applied, when the treatment is applied and how many cures are applied.

CONCLUSION

Guides introducing which concentrations of PRP are used for which diseases are to be prepared immediately by a committee which is comprised of primarily orthopedists, clinical pharmacologists and toxicologists.

Application of Tendon Stem/Progenitor Cells and Platelet-Rich Plasma to Treat Tendon Injuries

Tendon injuries like tendinopathy are a serious healthcare problem in the United States. However, current treatments for tendon injuries are largely palliative. Biologics treatments, including tendon stem/progenitor cells (TSCs) and platelet rich plasma (PRP) hold great potential to effectively treat tendon injuries. TSCs are tendon specific stem cells and have the ability to differentiate into tenocytes, the resident tendon cells responsible for tendon homeostasis and tendon repair in case of an injury. TSCs can also self-renew and thus can replenish the tendon with tendon cells (TSCs and tenocytes) to maintain a healthy tendon. The action of PRP can be complementary; PRP can augment and accelerate tendon healing by supplying abundant growth factors contained in platelets, and fibrin matrix, which functions as a natural conducive scaffold to facilitate tissue healing. This article provides a summary of the findings in recent basic and clinical studies on the applications of TSCs and PRP to the treatment of tendon injuries. It also outlines the challenges facing their applications in clinical settings. In particular, the controversy surrounding the efficacy of PRP treatment for tendon injuries are analyzed and solutions are suggested.

A systematic review and meta-analysis of the application of platelet rich plasma in sports medicine

Introduction

In recent years, platelet rich plasma (PRP) has been receiving increasing attention for the treatment of soft tissue injuries. These numerous applications have raised a great deal of questions and debate about the effectiveness of this method. This study aimed to determine the efficacy of PRP in improving sports injuries and subsequently throw some light on these controversies.

Methods

A systematic review of the literature and meta-analysis of results were undertaken. All related databases, such as PubMed, Cochrane Database of Systematic Reviews, DARE, and EMBASE, were searched on the use of PRP on athletes and in sports medicine. The search was conducted from June 2013 to February 2014.

Results

Our search retrieved 905 studies, of which 13 randomized control trials (RCT) met our inclusion criteria for systematic review and meta-analysis. All articles were appraised by Critical Appraisal Skills Program (CASP) checklist for RCT studies. The analysis of the results of pain scores and physical activity/functions did not show any superiority for PRP as opposed to the other options.

Conclusions

The meta-analysis showed no more effectiveness for PRP application in sports-related injuries in terms of physical function improvement and pain relief. Therefore, the extensive use of PRP for such injuries should be limited. Well-designed RCTs are needed to support the findings.

Platelet-rich plasma versus open surgical release in chronic tennis elbow: A retrospective comparative study

PURPOSE

To compare short and mid-term results in the treatment of chronic elbow tendinosis with platelet-rich plasma (PRP) or Nirschl surgical technique.

METHOD

A retrospective study was conducted on patients with chronic lateral epicondylitis, treated by Nirschl surgical technique (50 elbows) or PRP (60 elbows). Outcome was evaluated with Visual Analog Score (VAS), Mayo Elbow Scores and grip strength measurements.

RESULTS

VAS and Mayo Elbow Scores of the PRP group had improved as a mean of 83% (p = 0.0001), 74% (p = 0.0001) over baseline and 34.2 pounds gain of grip strength.

CONCLUSION

The PRP seems to be better for pain relief and functionality in the short and mid-term periods.

Autologous leukocyte-reduced platelet-rich plasma therapy for Achilles tendinopathy induced by collagenase in a rabbit model

Leukocyte-reduced platelet-rich plasma (LR-PRP) is a therapy for tendinopathy of the Achilles tendon (TAT); however, there is scarce information regarding LR-PRP effects in rabbit models of TAT. We compared, at 4 and 12 weeks (w), the LR-PRP and placebo (PBS) effects on ultrasonography, histology and relative gene expression of collagen types I (COL1A1) and III (COL3A1) and vascular endothelial growth factor (VEGF) in 24 rabbits with TAT induced by collagenase. The rabbits (treated with both treatments) were euthanatised after either 4 or 12 w. A healthy group (HG (n = 6)) was included. At 4 and 12 w, the LR-PRP group had a no statistically different histology score to the HG. At w 4, the COL1A1 expression was significantly higher in the LR-PRP group when compared to HG, and the expression of COL3A1from both LR-PRP and PBS-treated tendons was significantly higher when compared to the HG. At w 12, the expression of COL3A1 remained significantly higher in the PBS group in comparison to the LR-PRP group and the HG. At w 4, the LR-PRP group presented a significantly higher expression of VEGF when compared to the PBS group and the HG. In conclusion, LR-PRP treatment showed regenerative properties in rabbits with TAT.

Platelet Rich Plasma Therapy in Non-insertional Achilles Tendinopathy: The Efficacy is Reduced in 60-years Old People Compared to Young and Middle-Age Individuals

Background: Platelet Rich Plasma (PRP) has shown positive and long-lasting effects in patients with tendinopathies. However, information about age-related differences in the clinical outcome is limited. Aim of this retrospective study was to compare the efficacy of PRP therapy in young and elderly subjects suffering for Achilles tendinopathy.

Materials and method: Patients with recalcitrant non-insertional Achilles tendinopathy were enrolled. Clinical (VISA-A) and instrumental (ultrasonography) data were collected at baseline and after 1, 3, 6, and 12 months. PRP injections (once a week for 3 weeks) were performed in sterile conditions and under ultrasound (US) control.

Results: Forty-four subjects (29 young: mean age 39.5 ± 6.9; 15 elderly: mean age 61.5 ± 5.3) were retrospectively evaluated. At baseline, no significant differences were observed in the clinical and US parameters. Throughout the whole length of the study, a significant increase of VISA-A score was seen in both groups (from 50.3 ± 8.8 to 76.1 ± 6.6 in the young group, and from 48.7 ± 7.6 to 61.1 ± 9.4 in the elderly group); however, the infra-groups comparison showed better results in young patients, compared to the aged counterpart.

Conclusion: Our results show that PRP is less effective in aged people. This finding can be ascribed to several biochemical and biomechanical differences documented in tendons of young and elderly subjects (reduced number and functionality of tenocytes and tenoblasts), which becomes more evident in the long-term tissue healing. However, prospective trials, using different PRP preparations and enrolling a larger number of subjects, are needed to draw more sound and definitive conclusions.

Recent Scientific Advances Towards the Development of Tendon Healing Strategies

There exists a range of surgical and non-surgical approaches to the treatment of both acute and chronic tendon injuries. Despite surgical advances in the management of acute tears and increasing treatment options for tendinopathies, strategies frequently are unsuccessful, due to impaired mechanical properties of the treated tendon and/or a deficiency in progenitor cell activities. Hence, there is an urgent need for effective therapeutic strategies to augment intrinsic and/or surgical repair. Such approaches can benefit both tendinopathies and tendon tears which, due to their severity, appear to be irreversible or irreparable. Biologic therapies include the utilization of scaffolds as well as gene, growth factor, and cell delivery. These treatment modalities aim to provide mechanical durability or augment the biologic healing potential of the repaired tissue. Here, we review the emerging concepts and scientific evidence which provide a rationale for tissue engineering and regeneration strategies as well as discuss the clinical translation of recent innovations.

Amniotic Tissues for the Treatment of Chronic Plantar Fasciosis and Achilles Tendinosis

Introduction. Allogeneic amniotic tissue and fluid may be used to treat chronic plantar fasciosis and Achilles tendinosis. This innovative approach involves delivering a unique allograft of live human cells in a nonimmunogenic structural tissue matrix to treat chronic tendon injury. These tissues convey very positive regenerative attributes; procurement is performed with maternal consent during elective caesarian birth. Materials and Methods. In the present investigation all patients were unresponsive to multiple standard therapies for a minimum of 6 months and were treated with one implantation of PalinGen SportFLOW around the plantar fascia and/or around the Achilles paratenon. The patients were given a standard protocol for postimplant active rehabilitation. Results. The analogue pretreatment pain score (VAS) of 8. By the fourth week after treatment, all patients had significantly reduced self-reported pain. Twelve weeks following the procedure the average pain level had reduced to only 2. No adverse reactions were reported in any of the patients. Conclusion. All patients in this study experienced heel or Achilles pain, unresponsive to standard therapy protocols. After treatment all patients noted significant pain reduction, indicating that granulized amniotic membrane and amniotic fluid can be successfully used to treat both chronic plantar fasciosis and Achilles tendinosis.

Leukocyte presence does not increase microbicidal activity of Platelet-rich Plasma in vitro

Background

Human platelets are a rich reservoir of molecules that promote regenerative processes and microbicidal activity. This activity might be increased by concentration in platelet-rich plasma (PRP) products and modulated by the presence of leukocytes. Despite extensive use in clinical procedures, only few studies have investigated PRP’s real microbicidal potential. Therefore, this study aimed at comparing the in vitro microbicidal activity of platelets and leukocyte-enriched PRP (L-PRP) to pure platelet-rich plasma (P-PRP) and the contribution of leukocytes to microbicidal properties.

Antimicrobial effects of P- and L-PRP were tested against Escherichia Coli, Staphylococcus Aureus, Klebsiella Pneumoniae, Pseudomonas Aeruginosa and Enterococcus Faecalis. Furthermore, L-PRP was frozen (L-PRP cryo) to assess whether the preparation maintained in vitro characteristics. Microbicidal proteins released by the three preparations were also evaluated.

Results

L-PRP, L-PRP cryo and P-PRP generally induced comparable bacterial growth inhibition for up to 4 h’ incubation, range 1–4 log. MIP-1α, RANTES, GRO-α, IL-8, NAP-2, SDF-1α and IL-6 showed strong microbicidal potential.

Conclusions

We found in vitro antibacterial activity of L-PRP and P-PRP and the possibility to cryopreserve L-PRP, without important changes to its effectiveness; similar microbicidal activity between preparations containing or not leukocytes; and the contribution of three new molecules (NAP-2, SDF-1α and IL-6).

Utilization of Platelet-Rich Plasma for a Fistula With Subcutaneous Cavity Following Septic Bursitis: A Case Report

In platelet-rich plasma (PRP) therapy, various growth factors and cytokines released the α-granules contained in platelets after activation can potentially enhance wound healing by delivering. We report a patient in whom treatment with PRP, prepared using a syringe-centrifugation-system PRP kit (KYOCERA Medical PRP Kit), for a fistula following bursitis of the lateral malleolus, which could not be healed with conventional wound therapy, led to successful healing. A 58-year-old man was on dialysis for type II diabetes and chronic renal failure. In the left lateral malleolus, septic bursitis developed, leading to a refractory fistula with a subcutaneous cavity measuring 4 × 3 cm, which persisted for more than 2 months. Platelet-rich plasma was prepared using the KYOCERA Medical PRP Kit (KYOCERA Medical Corporation, Osaka, Japan) and infused into the cavity twice to close it. After this procedure, the cavity size reduced, but the orifice and subcutaneous cavity were not closed. Therefore, additional PRP therapy was conducted after 10 weeks of the first PRP session. Complete closure was achieved 13 weeks after the first PRP therapy. In the present case, PRP was prepared using the KYOCERA Medical PRP Kit, and wound healing of a fistula with subcutaneous cavity following bursitis of the lateral malleolus was successfully cured. The KYOCERA Medical PRP Kit was useful, because PRP could be prepared simply and inexpensively using the syringe-centrifugation system.

Tendinopathies and platelet-rich plasma (PRP): from pre-clinical experiments to therapeutic use

OBJECTIVES

The restorative properties of platelets, through the local release of growth factors, are used in various medical areas. This article reviews fundamental and clinical research relating to platelet-rich plasma applied to tendinous lesions.

MATERIALS AND METHOD

Articles in French and English, published between 1 January 2012 and 31 December 2014. dealing with PRP and tendons were searched for using the Medline and Scopus data bases.

RESULTS

Forty-seven articles were identified which addressed pre-clinical and clinical studies: 27 relating to in vitro and in vivo animal studies and 20 relating to human studies. Of these, five addressed lateral epicondylitis, two addressed rotator cuff tendinopathies, ten dealt with patellar tendinopathies and three looked at Achilles tendinopathies.

CONCLUSIONS

The majority of pre-clinical studies show that PRP stimulates the tendon's healing process. However, clinical series remain more controversial and level 1, controlled, randomised studies are still needed.

Platelet-rich plasma to treat ankle cartilage pathology - from translational potential to clinical evidence: a systematic review

Platelet-rich Plasma (PRP) is a fascinating biological treatment showing promising results for the management of cartilage disorders. However, despite the step forwards in this research area and the increasing use of PRP in clinical practice, its use remains still controversial and especially its application as injective treatment for ankle cartilage pathology have been scarcely investigated.

The aim of this paper is to describe the translational evidence for the use of PRP in cartilage treatment and to systematically review all the available evidence regarding the clinical application of PRP for ankle cartilage disorders, in order to understand what is the current state of the art for this specific clinical indication, underlining both limits and potential of this biological strategy.

A systematic review of the clinical literature was performed on the use of PRP to treat ankle cartilage disorders and 7 papers were identified. PRP has been used in two different ways: 5 of the available papers focus on its use as an augmentation procedure to various surgical techniques for cartilage regeneration, while only two studies report its conservative application through intra-articular injections. Based on the limited number of clinical studies available on this topic, this systematic review showed the lack of major adverse events related to PRP and overall good results for the treatment of ankle cartilage pathology, thus confirming the translational potential of this biological treatment suggested by several preclinical studies. Further high quality clinical trials in the ankle are still needed to clarify proper indications and best applicative modalities.

Platelet-rich plasma: evidence for the treatment of patellar and Achilles tendinopathy--a systematic review

Platelet-rich plasma (PRP) has been introduced in the clinical practice to treat a growing number of different musculoskeletal pathologies. It is currently applied in the treatment of Achilles and patellar tendinopathies, which are common sport-related injuries very challenging to manage. Aim of the present paper was to review systematically the available clinical evidence concerning the application of PRP in the treatment of patellar and Achilles tendinopathy. A systematic review of the literature was performed according to the following inclusion criteria for relevant articles: (1) clinical reports of any level of evidence, (2) written in the English language, (3) with no time limitation and (4) on the use of PRP to treat conservatively Achilles and patellar tendinopathy. Twenty-two studies were included and analyzed. Two studies on patellar tendinopathy were randomized controlled trials (RCTs), whereas just one RCT was published on Achilles tendon. All the papers concerning patellar tendon reported positive outcome for PRP, which proved to be superior to other traditional approaches such as shock-wave therapy and dry needling. In the case of Achilles tendon, despite the encouraging findings reported by case series, the only RCT available showed no significant clinical difference between PRP and saline solution. The main finding of this study was the paucity of high-level literature regarding the application of PRP in the management of patellar and Achilles tendinopathy. However, the clinical data currently available, although not univocal, suggest considering PRP as a therapeutic option for recalcitrant patellar and Achilles tendinopathies.