Platelet-rich plasma in orthopaedic sports medicine: state of the art

Blood flow restriction-enhanced platelet-rich plasma: A pilot randomised controlled trial protocol

Purpose

To assess platelet-rich plasma (PRP) changes in platelet and leucocyte count, insulin-like growth factor 1 (IGF-1), and interleukin 6 (IL-6) concentration after bilateral low-load knee extensions under blood flow restriction (BFR).

Methods

The present randomised controlled trial protocol will include two groups: the intervention group, which will undergo bilateral knee extensions under BFR, and the control group, which will perform bilateral knee extensions without BFR. Participants will be randomly allocated in a 1:1 ratio. Twenty-two healthy individuals will be enrolled if the predefined inclusion criteria are met: (1) males, (2) ages 18-40, (3) Tegner activity level ≥5 and (4) with no musculoskeletal conditions that would interfere with exercise. Exclusion criteria include (1) individuals with systemic inflammatory diseases, (2) cardiovascular risk factors, (3) any blood dyscrasia, (4) Tegner Activity scale scores <5, (5) under nonsteroidal anti-inflammatory drugs and aspirin treatment within one week before testing or (6) that had previously performed exercises on the testing day. The participant will perform low-load bilateral knee extensions under BFR following a standard protocol of 30-15-15-15 repetitions of consecutive sets with 30-s rest intervals at 80% of limb occlusive pressure and 30% of 1-RM load. PRP platelet and leucocyte count, IGF-1 and IL-6 concentration measurements (via flow cytometry, chemiluminescence testing and immunochromatography, respectively) will be conducted before exercise and 10, 20 and 30 min after the intervention.

Results

The expected outcome is that the standard protocol of low-load bilateral knee extensions under BFR will increase the platelet and leucocyte count, IGF-1 and IL-6 in the PRP preparation.

Conclusion

The current protocol allows the study of an enhanced PRP formulation for its potential implementation in multiple sports injuries.

Use of platelet-rich plasma in rheumatic diseases

Platelet-rich plasma (PRP) has gained increasing recognition as a promising therapeutic agent in managing rheumatic diseases. Conventional treatments, including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and disease-modifying antirheumatic drugs (DMARDs), primarily act on reducing inflammation but fail to address the underlying mechanisms of connective tissue degradation. PRP, an autologous preparation enriched with growth factors and bioactive molecules, is pivotal in modulating inflammation and fostering tissue regeneration. This review overviews the therapeutic potential of PRP across a spectrum of rheumatic diseases, such as osteoarthritis (OA), rheumatoid arthritis (RA), systemic sclerosis (SSc), and osteonecrosis. The regenerative capacity of PRP, driven by vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and transforming growth factor-beta (TGF-β), promotes tissue repair, reduces cartilage damage and improves joint function. Emerging evidence supports the efficacy of PRP in early-stage OA, demonstrating superior outcomes over traditional therapies like hyaluronic acid and glucocorticoids in terms of pain relief and functional improvement. Despite its benefits, PRP therapy is characterized by variability in treatment responses, with challenges in standardizing preparation protocols and treatment regimens. This review highlights the need for robust clinical trials to establish uniform treatment protocols, optimize patient selection, and evaluate the long-term clinical outcomes of PRP therapy in rheumatic diseases.

Current Challenges in the Development of Platelet-Rich Plasma-Based Therapies

Nowadays, biological therapies are booming and more of these formulations are coming to the market. Platelet-rich plasma, or PRP, is one of the most widely used biological therapies due to its ease of obtention and autologous character. Most of the techniques to obtain PRP are focusing on new processes and methods of optimization. However, not enough consideration is being given to modify the molecular components of PRP to generate more effective formulations with the aim of improving PRP treatments. Therefore, this review covers different novel PRP-obtaining methods that attempt to modify the molecular composition of the plasma.

Surgical and Biological Treatment with a Platelet-Rich Fibrin Matrix for Patellar Tendinopathy: Clinical Outcomes and Return to Sport at 2-Year Follow-Up

BACKGROUND

Patellar tendinopathy (PT) involves anterior knee pain and functional. Platelet-rich fibrin matrix (PRFM) is a promising biological therapy for tendinopathies. We examined a cohort of PT patients treated with tendon debridement and autologous PRFM at the 24-month follow-up to assess whether the combined treatment facilitated return to sports and yielded satisfactory clinical and functional scores.

METHODS

Baseline and 24-month visual analogue scale (VAS), Victorian Institute of Sport Assessment Scale for Patellar Tendinopathy (VISA-P), Tegner Activity Scale (TAS), and Blazina scores were compared to evaluate treatment effectiveness. The Friedman test was used to compare repeated observations of VAS, VISA-P, TAS, and Blazina Score values. Return to sport rate, Tampa Scale of Kinesiophobia (TKS) score and patient satisfaction were collected at 24 months.

RESULTS

The postoperative clinical scores demonstrated significant improvement compared with their preoperative values (all p < 0.001). Specifically, the VISA-P score was 80.32 (±20.58), 92.10% of patients had resumed sports activities and patient satisfaction was 9.21 (±1.21) at 24 months.

CONCLUSIONS

Surgical debridement and autologous PRFM application in patients with chronic PT resulted in a higher rate of return to sports when compared to solely surgical treatment, significantly improved clinical outcomes and excellent patient satisfaction at 24 months.

Platelet-Rich Plasma (PRP) for Endometrial Treatment Efficacy and Safety in Assisted Reproductive Technology: A Comprehensive Review

Platelet-rich plasma (PRP) is among the new ground-breaking methods called for endometrial disorders detected in assisted reproductive technology (ART). This research work takes account of both a systematic literature review and an exploration of the molecular connections. The report aims to present the capabilities and benefits of the PRP in ART and the nonconformance and dangers involved in its use in ART. However, all these stages of ART need conducive endometrium, live micro embryo, and coordinated interaction between the blastocyst and the uterus. Despite all ART has achieved, implantation failure still exists as a problem having one quarter being attributed to the absence of the endometrial receptivity level. The review points to a corresponding increase in the role of autologous PRP in promoting cell proliferation, neo-angiogenesis, and anti-inflammatory effects to facilitate effective endometrial receptivity. The outcome of prior trials with the PRP approach proved to be positive for women with adenomyosis, thin endometrial lining, recurring implantation failure, chronic endometritis, and Asherman's syndrome. Challenges still exist in the proper placement of PRP for all women with infertility problems as well as how it works for individuals with blood disorders and infections. This study will look into the safest number of doses, the time of acting, and the possible future health hazards that both mother and child may face.

Percutaneous Interventions for Injuries in Athletes: Implications on Return to Play

For nonsurgical musculoskeletal (MSK) injuries in athletes, image-guided percutaneous intervention may aid in recovery and decrease return to play (RTP) time. These interventions fall into two major categories: to reduce inflammation (and therefore alleviate pain) or to promote healing. This review describes the risks and benefits of the various percutaneous interventions in MSK athletic injury and surveys the literature regarding the implication of these interventions on RTP.

Therapeutic approaches of cell therapy based on stem cells and terminally differentiated cells: Potential and effectiveness

Cell-based therapy, as a promising regenerative medicine approach, has been a promising and effective strategy to treat or even cure various kinds of diseases and conditions. Generally, two types of cells are used in cell therapy, the first is the stem cell, and the other is a fully differentiated cell. Initially, all cells in the body are derived from stem cells. Based on the capacity, potency and differentiation potential of stem cells, there are four types: totipotent (produces all somatic cells plus perinatal tissues), pluripotent (produces all somatic cells), multipotent (produces many types of cells), and unipotent (produces a particular type of cells). All non-totipotent stem cells can be used for cell therapy, depending on their potency and/or disease state/conditions. Adult fully differentiated cell is another cell type for cell therapy that is isolated from adult tissues or obtained following the differentiation of stem cells. The cells can then be transplanted back into the patient to replace damaged or malfunctioning cells, promote tissue repair, or enhance the targeted organ's overall function. With increasing science and knowledge in biology and medicine, different types of techniques have been developed to obtain efficient cells to use for therapeutic approaches. In this study, the potential and opportunity of use of all cell types, both stem cells and fully differentiated cells, are reviewed.

Severe mucoid degeneration of the anterior cruciate ligament (ACL) treated with conservative arthroscopic debridement and platelet-rich plasma (PRP) injection

Mucoid degeneration of the anterior cruciate ligament (ACL) can be treated with arthroscopic debridement, however, instability can ensue. Here, we present a fit and active woman in her 60s with severe mucoid degeneration of the ACL who underwent conservative arthroscopic debridement and treatment with intraligamentous administration of platelet-rich plasma (PRP). After 1 month, the patient demonstrated significant improvements in range of motion and pain symptoms, with nil resultant laxity. The patient was able to return to all recreational sporting activities and professional duties. Quantitative MRI conducted 6 months postoperatively revealed improved fibre orientation and formation of new parallel fibres. Compared with the preoperative scan, the mean grey value demonstrated darker pixel intensity with a smaller standard deviation (SD), potentially indicating a more uniform and less variable formation of ligamentous tissue. Therefore, PRP did not cause harm and was associated with benefit in combination with arthroscopic debridement.

Recent advances in platelet-rich plasma and its derivatives: therapeutic agents for tissue engineering and regenerative medicine

Platelet rich plasma (PRP) is a suspension of bioactive factors and chemokine enriched plasma. Platelets are a distinctive source of membrane bound and soluble proteins that are released upon their activation. The higher count of platelets renders PRP with an array of tissue regenerative abilities. PRP can be employed in the form of platelet containing plasma, platelet lysate plasma, or in the form of a pre-gelled fibrin matrix. PRP has been an essential alternative source of growth factors in the healing and regeneration of various tissues, such as musculoskeletal, cardiovascular, and dermal tissue, with additional applications in other tissues, such as hepatic and neural. A wide range of preparative and isolation strategies have been developed for various forms of PRP at laboratory and commercial scales. Concomitantly, PRP has found its applicability as an active component in several tissue regenerative approaches, including 3D printed/bioprinted constructs, injectable hydrogels, and crosslinked scaffolds. This review focuses on the various forms of PRP and their preparation methods, the latest tissue engineering applications of PRP, and the various tissue-specific clinical trials and findings conducted using PRP. We have further discussed the optimizations required in the methods of preparation, delivery, and long-term storage of PRP. Therefore, this review seeks to benefit the scope of research on PRP-based therapeutic agents in tissue engineering by providing comprehensive insights into the widespread application. We envisage PRP could be instrumental in future patient-specific tissue engineering applications in both pre-clinical and clinical settings.

Elevated IL-1β and Comparable IL-1 Receptor Antagonist Levels Are Characteristic Features of L-PRP in Female College Athletes Compared to Male Professional Soccer Players

Autologous platelet-rich plasma (PRP) therapy has been becoming popular for the treatment of musculotendinous injuries among athletes. However, for individual and practical variations, clinical success is hardly predictable. To overcome this difficulty, we have been exploring possible criterion candidates for monitoring its clinical effectiveness. In this study, we focused on sex-based differences in young elite athletes and compared the biochemical compositions of their PRP. Leukocyte-rich PRP (L-PRP) was manually prepared from blood samples collected from male professional soccer players (mPSPs) (n = 25) and female college athletes (fCAs) (n = 36). Platelet-derived growth factor-BB (PDGF-BB), transforming-growth factor-β1 (TGFβ1), platelet factor-4 (PF4), interleukin-1β (IL-1β), and IL-1 receptor antagonist (IL-1RA) were quantified using an enzyme-linked immunosorbent assay. The levels of PDGF-BB, TGFβ1, and PF4 in L-PRP were significantly higher in mPSPs than in fCAs. Conversely, IL-1β and IL-1RA were detected at significantly and slightly higher levels, respectively, in fCAs than in mPSPs. Our findings suggest that, even though L-PRP from fCAs may have lower potential to induce cell growth and differentiation than that of mPSPs, due to the latter's higher capacity to control inflammation, it does not necessarily imply that PRP treatment in fCAs is less effective. Thus, these cytokine levels should be checked before PRP therapy.

Characterization of Leukocyte- and Platelet-Rich Plasma Derived from Female Collage Athletes: A Cross-Sectional Cohort Study Focusing on Growth Factor, Inflammatory Cytokines, and Anti-Inflammatory Cytokine Levels

Platelet-rich plasma (PRP) has been increasingly used in sports medicine owing to its various advantages. The purpose of our project was to standardize the parameters before performing large-scale clinical trials in the near future to precisely evaluate individual PRP quality. To examine the effects of regular exercise on PRP quality, this study focused on young female athletes, who have been relatively less studied. Blood samples were obtained from female college athletes (n = 35) and ordinary healthy adults (n = 30), which were considered as controls, and leukocyte-rich PRP (L-PRP) was prepared manually. Body composition indices were determined using a bathroom weight scale equipped with an impedance meter. Growth factors and cytokines were quantified using ELISA kits. Platelet-derived growth factor-BB (PDGF-BB) and Transforming-growth factors β1 (TGFβ1) levels (per platelet) in L-PRP were significantly lower in female athletes than in controls. In contrast, Interleukin-1β and Interleukin 1 receptor antagonist (IL-1RA) levels (per platelet and L-PRP) in L-PRP were significantly higher in athletes, and this difference was more prominent in IL-1RA. These findings suggest that L-PRP from athletes may facilitate the inflammatory phase of the healing process by regulating the pro-inflammatory and anti-inflammatory balance. These chemical compositions can be adopted as "must-check" parameters to characterize individual PRP preparations prior to clinical trials.

Study protocol for double-blind, randomised placebo-controlled trial evaluating semitendinosus function and morbidity following tendon harvesting for anterior cruciate ligament reconstruction augmented by platelet-rich plasma

INTRODUCTION

Anterior cruciate ligament (ACL) rupture is debilitating, often requiring surgical reconstruction. An ACL reconstruction (ACLR) using a tendon autograft harvested from the semitendinosus results in substantial injury to the donor muscle. Following ACLR, patients rarely return to their preinjury level of physical activity, are at elevated risk of secondary lower limb injuries and early onset knee osteoarthritis. To date, no randomised controlled trial has evaluated the efficacy of platelet-rich plasma (PRP) in aiding knee function and semitendinosus morphology of following ALCR.

METHODS AND ANALYSIS

This is a multicentre double-blind randomised placebo-controlled trial. Fifty-four ACLR patients aged 18-50 years will be randomised to receive either a single application of PRP (ACLR+) or placebo saline (ACLR) into the semitendinosus harvest zone at the time of surgery. All patients will undergo normal postoperative rehabilitation recommended by the attending orthopaedic surgeon or physiotherapist. The primary outcome measure is between-limb difference (ACLR compared with intact contralateral) in isometric knee flexor strength at 60o knee flexion, collected 10-12 months postsurgery. This primary outcome measure will be statistically compared between groups (ACLR+ and standard ACLR). Secondary outcome measures include bilateral assessments of hamstring muscle morphology via MRI, biomechanical and electromyographic parameters during an anticipated 45° running side-step cut and multidirectional hopping task and patient-reported outcomes questionaries. Additionally, patient-reported outcomes questionaries will be collected before (baseline) as well as immediately after surgery, and at 2-6 weeks, 3-4 months, 10-12 months and 22-24 months postsurgery 10-12 months following surgery.

ETHICS AND DISSEMINATION

Ethics approval has been granted by Griffith University Human Research Ethics Committee, Greenslopes Research and Ethics Committee, and Royal Brisbane & Women's Hospital Human Research Ethics Committee. Results will be submitted for publication in a peer-reviewed medical journal.

TRIAL REGISTRATION NUMBER

ACTRN12618000762257p.

Platelet-rich plasma injection vs. operative treatment for lateral elbow tendinosis: a systematic review and meta-analysis

BACKGROUND

Although surgical treatment is considered reliable for lateral elbow tendinosis, local injection therapy may be preferable, as it avoids surgery. Among a number of local injections, platelet-rich plasma has been used successfully to treat lateral elbow tendinosis. The purpose of this study was to compare the outcomes in patients treated with either platelet-rich plasma injections or surgery for lateral elbow tendinosis using a systematic literature review and meta-analysis.

METHODS

MEDLINE, Embase, and Cochrane Library databases were systematically searched for studies published before March 1, 2021, that compared platelet-rich plasma with operative treatment for lateral elbow tendinosis. The pooled analysis was designed to compare the visual analog scale scores and the Patient-Related Tennis Elbow Evaluation scores between the platelet-rich plasma and surgical treatment groups at serial time points.

RESULTS

We included 5 studies involving 340 patients with lateral elbow tendinosis, comprising of 154 patients treated with platelet-rich plasma and 186 patients who underwent surgical treatment. The pooled analysis showed no statistically significant differences in the visual analog scale scores at any of the follow-up time points, namely, 2 months (mean difference [MD] 1.11, 95% confidence interval [CI] -2.51 to 4.74, P = .55, I² = 94%), 6 months (MD 0.80, 95% CI -2.83 to 4.42, P = .67, I² = 92%), and 12 months (MD -0.92, 95% CI -4.63 to 2.80, P = .63, I² = 93%) postintervention and in the Patient-Related Tennis Elbow Evaluation scores at 12 weeks (MD -1.86, 95% CI -22.30 to 18.58, P = .86, I² = 81%), 24 weeks (MD -3.33, 95% CI -21.82 to 15.17, P = .72, I² = 74%), and 52 weeks (MD -3.64, 95% CI -19.65 to 12.37, P = .66, I² = 69%) postintervention.

CONCLUSIONS

Local platelet-rich plasma injections and surgical treatment produced equivalent pain scores and functional outcomes in patients with lateral elbow tendinosis. Thus, platelet-rich plasma injections may represent a reasonable alternative treatment for patients who are apprehensive to proceed with surgery or for poor surgical candidates.

Platelet-Rich Plasma Versus Hyaluronic Acid for Knee Chondral Injuries In Young Patients

Objective  The present study aimed to compare the clinical and functional outcomes of hyaluronic acid (HA) or platelet-rich plasma (PRP) applications to treat young patients with knee chondral lesions with no arthrosis.

Methods  Prospective clinical and functional evaluation of 30 young adult patients with knee chondral lesions submitted to conservative treatment with HA or PRP for a minimum follow-up time of 12 months. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) and visual analog scale (VAS) were used for the evaluation.

Results  According to the WOMAC score, the PRP group showed significant improvement in all evaluated points, whereas the HA group presented no score improvement. In the VAS, the PRP group showed improvement in all evaluated points, and the HA group presented improvement at 6 and 12 months. Compared to the HA group, the PRP group presented better WOMAC scores at all evaluated points and better VAS scores up to 6 months after treatment.

Conclusion  Platelet-rich plasma application resulted in better clinical and functional outcomes at both the WOMAC and VAS scores when applied to knees from young patients with chondral lesions, but no arthrosis. These outcomes were sustained for up to 12 months.

Level of evidence  Randomized clinical trial (Type 2B)

Human platelet lysate - A potent (and overlooked) orthobiologic

The knowledge of the essential role of platelets in tissue healing is gradually increasing and as regenerative medicine prompts new solutions, platelet-derived bioproducts have been proposed as a potential tool in this field. In orthopaedics and sports medicine, the use of PRP has been rapidly increasing in popularity as patients seek novel non-surgical approaches to acute and chronic musculoskeletal conditions. The concept of having platelets as a secretory organ other than a mere sponge-like coagulation component opens up new frontiers for the use of the platelet secretome. Platelet lysate is a solution saturated by growth factors, proteins, cytokines, and chemokines involved in crucial healing processes and is administered to treat different diseases such as alopecia, oral mucositis, radicular pain, osteoarthritis, and cartilage and tendon disorders. For this purpose, the abundant presence of growth factors and chemokines stored in platelet granules can be naturally released by different strategies, mostly through lyophilization, thrombin activation or ultrasound baths (ultrasonication). As a result, human platelet lysate can be produced and applied as a pure orthobiologic. This review outlines the current knowledge about human platelet lysate as a powerful adjuvant in the orthobiological use for the treatment of musculoskeletal injuries, without however failing to raise some of its most applicable basic science.