Single- and double-dose of platelet-rich plasma versus hyaluronic acid for treatment of knee osteoarthritis: A randomized controlled trial

Platelet-rich plasma alleviates knee arthritis in rats by inhibiting p65

Knee osteoarthritis (KOA) is a chronic joint disease characterized by the degeneration of articular cartilage. In this study, we explored the potential therapeutic effects of platelet-rich plasma (PRP) and identified molecular targets for treating KOA. A rat model of KOA was established via the Hulth method and primary knee joint chondrocytes were isolated to evaluate the effects of PRP and shRNA targeting p65 (sh-p65). ELISA was used to detect inflammatory factors, including IL-6, IL-1β, and TNF-α. HE staining, Safranin O/Fast Green staining and Masson staining were performed to evaluate the morphology of articular cartilage, followed by detection of p65, COL2A1, ACAN, MMP13, and ADAMTS5 expression. The proliferation and apoptosis of primary knee chondrocytes were detected by the CCK-8 assay and TUNEL staining, respectively. Treatment with either PRP or sh-p65 decreased IL-6, IL-1β, and TNF-α levels in the peripheral blood of KOA rats and chondrocyte culture supernatants, increased COL2A1 and ACAN levels, and decreased MMP13 and ADAMTS5 expression. Furthermore, administration of PRP or sh-p65 exerted protective effects on articular cartilage, enhanced the vitality of knee joint chondrocytes, and inhibited apoptosis. Collectively, PRP inhibited inflammation, promoted chondrocyte proliferation and cartilage matrix secretion, and induced cartilage regeneration by suppressing p65 expression; these effects allow PRP to alleviate KOA progression. P65-based targeted therapy administered in combination with PRP might be a promising strategy for treating KOA.

The varying clinical effectiveness of single, three and five intraarticular injections of platelet-rich plasma in knee osteoarthritis

OBJECTIVE

To investigate the variations in clinical effectiveness among patients diagnosed with knee osteoarthritis who underwent intra-articular administration of platelet-rich plasma using single, triple, or quintuple injections.

METHODS

One hundred twenty patients with grade I-III knee osteoarthritis were randomly assigned to three groups: PRP1 group, who received a single injection of platelet-rich plasma; PRP3 group, who received three PRP injections one week apart; PRP5 group, who received five PRP injections one week apart. The patients' conditions were evaluated using the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Arthritis Index-VA3.1 version (WOMAC-VA3.1) at baseline and 6, 12, 24, and 52 weeks 52 weeks follow up.

RESULTS

Out of the total participants, 106 patients (30 males and 76 females) completed the study. The primary outcome measure, WOMAC pain score, registered significant improvements across all groups when compared to pre-treatment levels. However, the application of 3 and 5 injections of platelet-rich plasma was substantially more effective than that of a single injection in reducing knee pain and stiffness, as well as enhancing physical function in patients with knee osteoarthritis. No statistically discernable difference was observed between PRP3 and PRP5 at all follow-up intervals, and there was no discernable difference between 3 and 5 PRP injections either. Mild side effects occurred in all three groups.

CONCLUSIONS

The administration of three or five injections of platelet-rich plasma is safe, substantially more effective than single injections, and leads to remarkable clinical improvement by significantly reducing knee pain, improving joint stiffness, and enhancing physical function in patients with grade I-III knee osteoarthritis. Furthermore, no significant difference was observed in the efficacy of three or five injections. Therefore, we recommend using three injections of PRP in the treatment of patients with knee osteoarthritis of grade I-III.

Randomized Controlled Trials on Platelet-Rich Plasma for Knee Osteoarthritis Poorly Adhere to the Minimum Information for Studies Evaluating Biologics in Orthopaedics (MIBO) Guidelines: A Systematic Review

BACKGROUND

Platelet-rich plasma (PRP) treatment for knee osteoarthritis has grown exponentially over the past decade; however, its scientific evaluation is highly variable. The American Academy of Orthopaedic Surgeons addressed the need for the standardization of orthobiologics studies by publishing the Minimum Information for Studies Evaluating Biologics in Orthopaedics (MIBO) guidelines in May 2017. In total, the MIBO guidelines are divided into 12 categories, encompassing 23 checklist items.

HYPOTHESIS/PURPOSE

The purpose of this study was to analyze how well randomized controlled trials (RCTs) on PRP interventions for knee osteoarthritis adhered to the MIBO guidelines. We hypothesized that most articles would report <80% of the MIBO criteria.

STUDY DESIGN

Systematic review; Level of evidence, 1.

METHODS

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were used to perform a systematic review in the PubMed/MEDLINE and Web of Science databases. Inclusion criteria included English-language RCTs that assessed PRP interventions for knee osteoarthritis and reported beginning patient enrollment in June 2017 or later. The original 23 MIBO checklist items were separated and modified into a 44-point checklist. Adherence was determined by calculating the total percentage of checklist items that each article adequately and clearly reported from the 44-point checklist.

RESULTS

A total of 25 RCTs (2356 patients) were included in this study. The weighted mean age was 57.7 ± 4.4 years, with 42.9% being male. On average, only 53.1% ± 10.4% (range, 31.8%-77.3%) of the 44-point MIBO checklist items were reported per article. No articles had adherence rates ≥80%, 5 (20.0%) had rates between 60% and 79.9%, and 20 (80.0%) had rates ≤59.9%. Categories fluctuated in adherence, with "Intervention" having the greatest adherence (100.0%) and "Activation" having the lowest (14.0%). Additionally, 4 (33.3%) categories had adherence rates ≥80%, 0 had rates from 60% to 79.9%, and 8 (66.7%) had rates ≤59.9%.

CONCLUSION

The overall mean adherence to MIBO guidelines by RCTs on PRP interventions for knee osteoarthritis was 53.1%. To increase the reproducibility, improve transparency, and assess the treatment efficacy of future PRP studies, reporting of MIBO guidelines should be improved.

Platelet-Rich Plasma Injections in Chronic Lateral Ankle Instability: A Case Series

The platelet-rich plasma (PRP) approach may be an effective treatment for joint and cartilage pathologies. However, the rationale for its effectiveness on joint instability is limited. This study aimed to assess the safety and effectiveness of PRP injections in patients with chronic lateral ankle instability (CLAI). This retrospective study was performed at a single-center outpatient clinic between January 2015 and February 2023 and included pre-intervention assessment and short-term follow-up. Patients were excluded if they had received previous surgical treatment or had constitutional hyperlaxity, systemic diseases, or grade II or III osteoarthritis. The clinical and functional evaluation consisted of the Karlsson score, the Cumberland Ankle Instability Tool (CAIT), Good's grading system, the patient's subjective satisfaction level, and the time required to return to exercise. The entire PRP therapy regime consisted of three PRP administrations at 7-day intervals and follow-up appointments. PRP was administered both intraarticularly and into talofibular ligaments. A total of 47 consecutive patients with CLAI were included, 11 were female (23.4%), with a mean age at intervention of 31.19 ± 9.74 years. A statistically significant improvement was found in the CAIT and Karlsson scores at 3 months (27.74 ± 1.68 and 96.45 ± 4.28, respectively) relative to the pre-intervention status (10.26 ± 4.33 and 42.26 ± 14.9, respectively, p < 0.000). The mean follow-up of patients with CLAI was 17.94 ± 3.25 weeks. This study represents successful short-term functional and clinical outcomes in patients with CLAI after PRP treatment, with no adverse effects. It demonstrates the feasibility of a randomized controlled trial to further assess this therapy.

American Academy of Orthopaedic Surgeons Technology Overview Summary: Platelet-Rich Plasma (PRP) for Knee Osteoarthritis

The Platelet-Rich Plasma (PRP) for Knee Osteoarthritis Technology Overview is based on a systematic review of current scientific and clinical research. Through analysis of the current best evidence, this technology overview seeks to evaluate the efficacy of PRP for patients with knee osteoarthritis. The systematic literature review resulted in 54 articles: 36 high-quality and 18 moderate-quality. The findings of these studies were summarized to present findings on PRP versus control/placebo, acetaminophen, non-steroidal anti-inflammatory drugs, corticosteroids, exercise, prolotherapy, autologous conditioned serum, bone marrow aspirate concentrate, hyaluronic acid, and ozone therapy. In addition, the work group highlighted areas that needed additional research when evidence proved lacking on the topic and carefully noted the potential harms associated with an intervention, required resource utilization, acceptability, and feasibility.

a comparison of intra-articular hyaluronic acid and platelet-rich plasma for knee osteoarthritis: a systematic review

Introduction

Knee osteoarthritis (KOA), the most common chronic degenerative condition in an older population, accounts for many disabilities around the world. One of the most popular treatments is intra-articular injection of hyaluronic acid (HA) and platelet-rich plasma (PRP).

Objective

Prior studies have found that both HA and PRP had a therapeutic effect on KOA. This study aims to perform a systematic review regarding whether PRP is superior to HA for KOA.

Method

We conducted a comprehensive literature search using Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines for prospective randomized control trials (pRCTs) in three international databases PubMed, Google Scholar, and ScienceDirect from 2019-2022. Two researchers independently searched the reviews, extracted, and cross-checked the data. The disparity when choosing the literature was resolved by discussion. The modified Jadad was scale used to assess the quality of the included studies. Cochrane risk of bias 2 tool (RoB-2) was used for determininzg risk of bias.

Results

Twenty three studies were eligible for inclusion. Four pRCT with the highest Jadad score were selected as best evidence. Risk of bias assesment concluded two studies having a low risk of bias, one is high risk of bias, and the other possesses some concerns.. Three studies found no difference in patient-reported outcomes between PRP and HA group and one study concluded that PRP is more effective than HA in treating KOA.

Conclusion

Intra-articular injections of PRP and HA are effective interventions for KOA. However, there is not enough evidence of PRP superiority over HA.

The Influence of Industry Affiliation on Randomized Controlled Trials of Platelet-Rich Plasma for Knee Osteoarthritis

BACKGROUND

Industry funding and corporate sponsorship have played a significant role in the advancement of orthopaedic research and technology. However, this relationship raises concerns for how industry association may bias research findings and influence clinical practice.

PURPOSE

To determine whether industry affiliation plays a role in the outcomes of randomized controlled trials (RCTs) investigating platelet-rich plasma (PRP).

STUDY DESIGN

Meta-analysis; Level of evidence, 2.

METHODS

A search of the PubMed, Cochrane, and MEDLINE databases for RCTs published between 2011 and the present comparing PRP versus hyaluronic acid, corticosteroid, or placebo for the treatment of knee osteoarthritis was performed. To determine industry affiliation, the conflict of interest, funding, and disclosure sections of publications were assessed, and all authors were assessed through the American Academy of Orthopaedic Surgeons disclosure database and the Centers for Medicare & Medicaid Services open payments database. Studies were classified as industry affiliated (IA) or non-industry affiliated (NIA). The outcomes of each study were rated as favorable, analogous, or unfavorable according to predefined criteria.

RESULTS

A total of 37 studies (6 IA and 31 NIA) were available for analysis. Overall, 19 studies (51.4%) reported PRP as favorable compared with other treatment options, while 18 studies (48.6%) showed no significant differences between PRP and other treatment methods. There was no significant difference in qualitative conclusions between the IA and NIA groups, with the IA group having 3 favorable studies and 3 analogous studies and the NIA group having 16 favorable studies and 15 analogous studies (P = .8881). When comparing IA versus NIA studies using 6- and 12-month Western Ontario and McMaster Universities Arthritis Index and International Knee Documentation Committee scores, there were no significant differences in outcomes.

CONCLUSION

The results of this study demonstrated that qualitative conclusions and outcome scores were found to not be associated with industry affiliation. Although the results of this study suggest that there is no influence of industry involvement on RCTs examining PRP, it is still necessary to carefully evaluate pertinent commercial affiliations when reviewing recommendations from studies before adopting new treatment approaches, such as the use of PRP for knee osteoarthritis.

Statistical Fragility of Randomized Controlled Trials Evaluating Platelet-Rich Plasma Use for Knee Osteoarthritis: A Systematic Review

Background

Numerous studies have been published on the use of platelet-rich plasma (PRP) for knee osteoarthritis (OA), with conflicting results.

Purpose

To determine the fragility index (FI) and fragility quotient (FQ) of randomized controlled trials (RCTs) that evaluated the use of PRP to treat knee OA.

Study Design

Systematic review.

Methods

RCTs evaluating the efficacy of PRP injections for knee OA from 2000 to 2020 were included for analysis according to PRISMA guidelines. The FI was determined by calculating the number of outcome event reversals required to change the statistical significance. The associated FQ was determined by dividing the FI by the sample size.

Results

Our initial search resulted in 41,149 studies, of which 8 RCTs (678 patients, 72 outcome events) were included in the analysis. One study failed to report PRP formulation details, whereas 87.5% of studies reported using either leukocyte-rich or leukocyte-poor PRP. The platelet concentration was reported in 25% of the included trials. The overall FI of the 72 outcome events was 8.5. Accounting for sample size, the associated FQ was determined to be 0.14, suggesting that the reversal of 14% of outcome events was required to change outcome significance. There were 51 statistically significant outcomes, of which the FI and FQ were 12 and 0.164, respectively.

Conclusion

Comprehensive fragility analysis suggested that the published literature evaluating the efficacy of PRP use for knee OA may lack statistical stability. We recommend the reporting of both an FI and FQ in addition to P value analysis to provide a clear and thorough understanding of the statistical integrity of studies reporting on PRP use for knee OA.

Comparison of Functional Outcome of Single Versus Multiple Intra-articular Platelet-Rich Plasma Injection for Early Osteoarthritis Knee

Background Osteoarthritis (OA) is a leading cause of pain and disability and has a negative impact on patients' quality of life. Platelet-rich plasma (PRP) has emerged as a promising treatment for various orthopaedic conditions, such as tendinopathies, nonunion, and arthritis of the knee. We sought to determine whether a single intra-articular platelet-rich plasma injection has better functional and pain outcomes when compared with multiple (two) articular platelet-rich plasma injections given in the early stages of OA of the knee, measured using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the visual analogue scale for pain (VAS) at the sixth week, third month, and sixth month. Materials and methods The prospective observational study was conducted among patients diagnosed with early OA who presented to the Department of Orthopaedics, R. L. Jalappa Hospital and Research Centre, Kolar, Karnataka, India, between January 2020 and June 2021. A total of 64 patients were divided into: (i) S-PRP group (34 patients), which received a single PRP injection, and (ii) M-PRP group (30 patients), which received multiple (two) PRP injections, one on presentation and the second in the thirdmonth. VAS and WOMAC scores to assess functional outcomes were used at the first visit before the intervention and at the sixth week, third month, and sixth month. Results The average age of the patients was 55.26 years in the S-PRP group and 51.13 years in the M-PRP group. Both genders were equal among study participants in the M-PRP group, but 79.4% were females in the S-PRP group. In the S-PRP group, 74% had grade II OA and 26% had grade I OA. In the M-PRP group, 60% had grade II OA and the remaining 40% had grade I OA. The decreasing trend of pain and functional limitation, which was measured by VAS and WOMAC, respectively, was observed in both groups at pre-injection, sixth week, third month, and sixth month. These differences were statistically significant. The mean difference in VAS score between the pre-injection period and at six months was 4 in the S-PRP group, whereas it was 5.77 in the M-PRP group, and this was statistically significant (p-value = 0.001). Thus, multiple PRP injections have a greater response to pain reduction when compared to single PRP injections, according to the VAS score. According to the WOMAC score, there is no statistically significant difference in the treatment response with PRP injection between the S-PRP and M-PRP groups at any follow-up period. Conclusion According to the VAS score, single PRP injections have a lower pain score than multiple PRP injections until three months of follow-up, while at six months, single PRP injections have no better effect than multiple PRP injections. But multiple PRP injections have a higher reduction in the intensity of pain when compared to single PRP injections during the follow-up period. According to the WOMAC score, there is no statistically significant difference in the treatment response with PRP injection between S-PRP and M-PRP groups.

How Does Platelet-Rich Plasma Compare Clinically to Other Therapies in the Treatment of Knee Osteoarthritis? A Systematic Review and Meta-analysis

BACKGROUND

There has been an increase in interest in the use of biological therapies in orthopaedic conditions such as knee osteoarthritis. Platelet-rich plasma (PRP) is one of these therapies, but it still lacks consistent results.

PURPOSE

To evaluate the effects (benefits and harms) of PRP intra-articular injection compared with other nonsurgical methods for the treatment of knee osteoarthritis.

STUDY DESIGN

Systematic review and meta-analysis of randomized and quasi-randomized controlled trials; Level of evidence, 2.

METHODS

Three electronic databases were searched to identify relevant studies published before January 2021. The primary outcomes were pain, function, and failure of treatment. Risks of bias of all trials were assessed using a Cochrane risk of bias tool. The Grading of Recommendations Assessment, Development and Evaluation System was used to assess the quality of evidence of included studies.

RESULTS

A total of 40 studies with 3035 participants were included. Analysis of this review focused on comparing PRP with hyaluronic acid, corticosteroid, and saline, as we believe they are the most relevant comparisons with the most studies available. At 6-month follow-up, PRP was as effective as and in some studies more effective than other therapies regarding pain, function, and stiffness. However, current evidence is of low or very low quality and is based on trials with high risk of bias and great heterogeneity among them. No significant difference among treatments was found concerning major adverse events and treatment failure.

CONCLUSION

Although studies suggest that PRP may be more effective than or at least as effective as other modalities of nonsurgical treatment for knee osteoarthritis in terms of pain, function, and adverse events, serious limitations and methodological flaws are considerable in the current literature. Therefore, the authors are not able to make recommendations for clinical practice regarding PRP for knee osteoarthritis.

Influence of platelet-rich plasma (PRP) analogues on healing and clinical outcomes following anterior cruciate ligament (ACL) reconstructive surgery: a systematic review

PURPOSE

To systematically review the effect of PRP on healing (vascularization, inflammation and ligamentization) and clinical outcomes (pain, knee function and stability) in patients undergoing ACL reconstruction and compare the preparation and application of PRP.

METHODS

Independent systematic searches of online databases (Medline, Embase and Web of Science) were conducted following PRISMA guidelines (final search 10th July 2021). Studies were screened against inclusion criteria and risk of bias assessed using Critical appraisal skills programme (CASP) Randomised controlled trial (RCT) checklist. Independent data extraction preceded narrative analysis.

RESULTS

13 RCTs were included. The methods of PRP collection and application were varied. Significant early increases in rate of ligamentization and vascularisation were observed alongside early decreases in inflammation. No significant results were achieved in the later stages of the healing process. Significantly improved pain and knee function was found but no consensus reached.

CONCLUSIONS

PRP influences healing through early vascularisation, culminating in higher rates of ligamentization. Long-term effects were not demonstrated suggesting the influence of PRP is limited. No consensus was reached on the impact of PRP on pain, knee stability and resultant knee function, providing avenues for further research. Subsequent investigations could incorporate multiple doses over time, more frequent observation and comparisons of different forms of PRP. The lack of standardisation of PRP collection and application techniques makes comparison difficult. Due to considerable heterogeneity, (I² > 50%), a formal meta-analysis was not possible highlighting the need for further high quality RCTs to assess the effectiveness of PRP. The biasing towards young males highlights the need for a more diverse range of participants to make the study more applicable to the general population.

TRAIL REGISTRATION

CRD42021242078CRD, 15th March 2021, retrospectively registered.

Biologic Therapies for the Treatment of Knee Osteoarthritis: An Updated Systematic Review

BACKGROUND

Use of "orthobiologics" continues to expand for patients who have knee osteoarthritis (OA). We sought to perform a systemic review of biologic therapies relative to comparative groups, including the following: (1) platelet-rich plasma (PRP); (2) bone marrow-derived mesenchymal stem cells (BMSCs); (3) adipose-derived mesenchymal stem cells (ADSCs); and (4) amniotic-derived mesenchymal stem cells (AMSCs). We assessed the following: (1) study methodologies; (2) cell preparations and formulations; (3) patient-reported outcome scores (PROMs); and (4) structural changes.

METHODS

PubMed, Cochrane Library, and Embase databases were queried (2013-2021) to conduct a systematic review of biologic therapies for knee OA, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eighty-two studies were included: PRP (51); BMSC (15); ADSC (11); and AMSC (5). Study evaluations were made using the Modified Coleman Methodology Score. PROMs included the Western Ontario and McMaster Universities Arthritis Index and the Visual Analog Scale. Structural change evaluations included ultrasounds, radiographs, or magnetic resonance imaging.

RESULTS

PRP comprised a majority of the studies (n = 51), most with "fair" to "good" Modified Coleman Methodology Score. Studies had variable cell preparations and formulations, with comparison study results leading to inconsistent PROMs, and structural changes. A limited number of studies were included for BMSC, ADSC, and AMSC, all with similar findings to PRP.

CONCLUSION

Available literature evaluating "orthobiologics" for knee OA remain nonsuperior to comparison cohorts. Higher level studies with larger sample sizes and improved methodologies are warranted to suggest differences. Despite a growth of "orthobiologics" in clinics, this updated systematic review highlights the uncertain efficacy for use in knee OA.

Is platelet-rich plasma better than hyaluronic acid in the treatment of knee osteoarthritis? A meta-analysis of randomized controlled trials

Introduction

Due to the complicated surgical procedure of knee arthroplasty and low effectivity of hyaluronic acid (HA) in the treatment of knee osteoarthritis, various studies highly recommend the use of platelet-rich plasma (PRP). However, some studies also reported lower efficacy and limited use of PRP.

Aim

To analyze systematically the different randomized controlled trials (RCTs) comparing the effectiveness of HA vs. PRP for the treatment of knee osteoarthritis.

Material and methods

A systematic literature review was conducted using Medline and Central databases for RCTs about the comparison of HA vs. PRP for the treatment of knee osteoarthritis. Studies were included as per the PICOS criteria and relevant event data were extracted. Risk of bias was analyzed and a random-effects model was used to calculate the pooled odds ratio and risk ratio using RevMan software.

Results

A total of 14 studies were included in the meta-analysis from year 2000 to 2021 including 613 patients. The current meta-analysis has a low risk of publication bias and we obtained the pooled odds ratio (OR) of 2.55 (95% CI: 1.35-4.84) with a τ ² value of 1.01, χ ² value of 52.79, I² value of 77%, Z value of 2.87 and p-value < 0.00001. The pooled risk ratio was 1.34 (95% CI: 1.09-1.65) with a τ ² value of 0.09, χ ² value of 73.48, I² value of 84%, Z value of 2.80 and p-value < 0.00001.

Conclusions

The current meta-analysis highly recommends the use of PRP for the treatment of knee osteoarthritis.

Intra-Articular Leukocyte-Rich Platelet-Rich Plasma versus Intra-Articular Hyaluronic Acid in the Treatment of Knee Osteoarthritis: A Meta-Analysis of 14 Randomized Controlled Trials

(1) Background: To evaluate the clinical effects of leukocyte-rich platelet-rich plasma (LR-PRP) and hyaluronic acid (HA) injections in treating patients suffering from knee osteoarthritis (OA); (2) Methods: Randomized controlled trials (RCTs) were searched from PubMed, Web of Science, and Cochrane Library. Keywords were: platelet-rich plasma, LR-PRP, leukocyte-rich, hyaluronic acid, and knee osteoarthritis. The included RCTs were published between the 1st of November 2011 and the 3rd of February 2021. Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores, visual analog scale (VAS) scores, International Knee Documentation Committee (IKDC) scores, and adverse events were used as outcomes for evaluation; (3) Results: A total of 14 RCTs were enrolled. At 6 months, revealed that the LR-PRP group was better than the HA group in WOMAC total, pain, and physical function scores. At 12 months, the LR-PRP group was better than the HA group in WOMAC stiffness and physical function scores. There was no significant difference in adverse events; (4) Conclusion: LR-PRP injection showed no significant pain relief effect as compared with HA injection. However, LR-PRP demonstrated better overall outcomes as compared to HA in knee OA patients at the follow-up periods of 3, 6, and 12 months. LR-PRP injection may be recommended as a feasible option in treating patients with knee OA.

Role and Effectiveness of Intra-articular Injection of Hyaluronic Acid in the Treatment of Knee Osteoarthritis: A Systematic Review

Osteoarthritis (OA) is a degenerative joint disease that causes persistent joint pain and stiffness of mainly the large peripheral weight-bearing joints. It is a leading cause of functional disability and poor quality of life. Various modalities of therapy are recommended by different research organizations at different stages of OA including non-pharmacological, pharmacological, and surgical interventions. Intra-articular injections of hyaluronic acid (HA) is widely used for over three decades in the treatment of OA. However controversies exist regarding its safety and efficacy, the number of injections and courses, type of preparation, duration of its effects, and combining it with other drugs or molecules. This study aimed to review the most recent data available in the published literature to address these.

Electronic databases like Medline, Embase, ProQuest, and Google Scholar were searched for articles using keywords, intraarticular injections, hyaluronic acid, and osteoarthritis knee. The review was carried out as per PRISMA guidelines.

Thirty-eight randomized control trials (RCTs) investigating the efficacy and safety of intra-articular injection of HA were included in the systematic review. Out of the 38 studies, 22 (57.9%) were double-blind, eight (21%) single-blind, three (7.9%) non-blind, four (10%) with simple randomization, and one (2.7%) was open-labeled. Total 5,025 patients were included in these studies. The mean age of the patients was 60.28 years and the osteoarthritis grade of the knee joint was 1 to 3. HA was studied as a test preparation in 19 (50%) while in another 19 (50%) it was studied as a control. In 24 (63.2%) studies, HA was used as high molecular weight preparation in eight (21%) as low molecular weight preparation while in six studies the information was not available. HA was used as a standalone preparation in 31 studies, in two studies it was injected with platelet-rich plasma (PRP) and with either low-level laser therapy (LLLT), triamcinolone (TA), betamethasone (CS), poly deoxyribonucleotide (PDRN) or dexamethasone (DX) in one study each. In the majority of the studies, HA was given as a single injection (52.6% studies) or weekly three injections (28.9% studies). In 13.2 %, it was given as weekly 5 injections and in 5.3% as weekly two injections.

IA-HA injections have a limited role in the treatment of knee osteoarthritis in those patients who do not have sufficient pain relief with topical or oral medication and physical therapy. It is safe and effective except for minor side effects such as local pain and swelling lasting for a few days. Severe allergic reactions are extremely rare. They provide adequate pain relief and functional improvement for up to six months irrespective of a number of injections and type of preparations used. The combination formulations with corticosteroids or PRP or MSCs show better results than HA alone. Combining HA with newer molecules such as peptides or diclofenac for sustained and disease-modifying effects requires more studies in the future.

Role of Platelets in Osteoarthritis-Updated Systematic Review and Meta-Analysis on the Role of Platelet-Rich Plasma in Osteoarthritis

Platelets are an essential component of hemostasis, with an increasing role in host inflammatory processes in injured tissues. The reaction between receptors and vascular endothelial cells results in the recruitment of platelets in the immune response pathway. The aim of the present review is to describe the role of platelets in osteoarthritis. Platelets induce secretion of biological substances, many of which are key players in the inflammatory response in osteoarthritis. Molecules involved in cartilage degeneration, or being markers of inflammation in osteoarthritis, are cytokines, such as tumor necrosis factor α (TNFα), interleukins (IL), type II collagen, aggrecan, and metalloproteinases. Surprisingly, platelets may also be used as a treatment modality for osteoarthritis. Multiple randomized controlled trials included in our systematic review and meta-analyses prove the effectiveness of platelet-rich plasma (PRP) as a minimally invasive method of pain alleviation in osteoarthritis treatment.

Single versus multi-dose intra-articular injection of platelet rich plasma in early stages of osteoarthritis of the knee: A single-blind, randomized, superiority trial

Objectives

This study aims to compare the effectiveness of single, double, and triple doses of intra-articular (IA) platelet rich plasma (PRP) in early stages of osteoarthritis (OA) of the knee.

Patients and methods

This single-blind, randomized, superiority trial included a total of 180 knees of 90 patients (22 males, 68 females; mean age: 47.9 years; range, 36 to 60 years) with bilateral OA knee of Kellgren-Lawrence Grade 1-2 between May 2017 and December 2018. The patients were randomized (30 in each group) to receive single, double, or triple doses of IA PRP (two weeks apart in repeat injections). The outcome measures were Visual Analog Scale, International Knee Documentation Committee Score, Knee Injury and Osteoarthritis Outcome Score, and Tegner Lysholm Knee Score. The assessor of outcome was blinded. The scores were collected before intervention and at six weeks, three months, six months, and one year after the intervention.

Results

All patients completed the study. All three groups were comparable with respect to demographic and disease characteristics. All four scores were comparable among the three groups before intervention and at six weeks, three months, and six months. However, at one-year follow-up, the three-dose group showed superiority to others in terms of all four scores. All three groups showed improvement until six months and deterioration thereafter, which was only marginal in the three-dose group. All groups showed a statistically significant improvement of scores compared to baseline scores at one year. There were no major complications.

Conclusion

The IA administration of three doses of PRP yields superior outcome to single and double doses at the end of one year. Repeat doses are probably needed to sustain the benefit achieved at one year.

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)

Comparative Analysis of the Effectiveness of Intra-Articular Injection of Platelet-Rich Plasma versus Hyaluronic Acid for Knee Osteoarthritis: Results of an Open-Label Trial

Background

Platelet-rich plasma (PRP), an autologous source of growth factors, and hyaluronic acid (HA) are among the minimally invasive treatments for knee osteoarthritis (OA). This trial was designed to compare the effectiveness of intra-articular injection of PRP with HA (as one of the standard treatments) on mild to moderate knee OA.

Methods

In this phase I open-label clinical trial, 10 patients underwent intra-articular PRP injection and 10 others received HA injection. At baseline (pre-injection) visit and 1, 3, 6, and 12 months post-injection, clinical assessments were performed using visual analogue scale (VAS) and Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire. Physical examinations of the knee, including crepitation and range of motion (ROM) were performed at each visit. The follow-up responses were compared with the baseline visit.

Results

The PRP treatment was ascertained to be safe and caused no adverse effects. Significant improvements in the majority of KOOS subscales and VAS were found throughout the entire 12-month follow-up, following the PRP injections. HA injection, however, caused only one month significant improvement in the majority of patient-reported outcomes. In the majority of visits, the extent of improvements in the scores of KOOS subscales, as well as the extent of reduction in VAS were significantly greater in PRP recipients, compared to HA recipients. The ROM in both groups slightly increased after interventions. The frequency of coarse crepitation, which was detected in 100% of the patients in both groups at the baseline visit, decreased significantly to fine crepitation at the first follow-up visit in 80% and 40% of the PRP and HA recipients, respectively.

Conclusion

Intra-articular injection of PRP or HA alleviates symptoms and pain and improves functionality and physical examinations in patients with knee OA. However, PRP therapy produces greater and longer-lasting improvements in most of the outcome parameters compared to HA.

Pain and functional outcomes of the sacroiliac joint after platelet-rich plasma injection: a descriptive review

The purpose of this manuscript is to highlight and review the status of literature regarding efficacy of platelet-rich plasma (PRP) in the treatment of sacroiliac joint (SIJ) dysfunction. A review of the literature on PRP interventions on the SIJ or ligaments was performed. Seven studies had improvements in their respective primary end point and demonstrated a strong safety profile without any serious adverse events. Only five articles demonstrated clinical efficacy of >50% in their primary outcome measures. There appears to be inconsistent and insufficient evidence for a conclusive recommendation for or against SIJ PRP. There is a need for adequately powered well-designed, standardized, double-blinded randomized clinical trials to determine the effectiveness of PRP in SIJ-mediated pain.

Impact of the numbers of injections of platelet rich plasma on the clinical outcomes in patients with knee osteoarthritis: A protocol for an updated network meta-analysis

BACKGROUND

Two published meta-analyses have investigated the effects of the number of injections of platelet rich plasma (PRP) on clinical outcomes in knee osteoarthritis patients, however conflicting findings were generated.

METHODS

We will systematically search PubMed, Embase, and China National Knowledgement Infrastructure (CNKI) to capture additional eligible studies. After screening citations, extracting essential data, assessing the risk of bias, we will use RevMan software and Open BUGS to perform head-to-head and network meta-analysis of pain alleviation and improvement of joint functionality, respectively.

DISCUSSION

Knee joint osteoarthritis (KOA) is the main cause of joint degeneration in elderly, which seriously reduces patients quality of life. Although intra-articular PRP has been extensively prescribed to treat KOA, a definitive conclusion about the appropriate number of injections has not yet been generated in published meta-analyses. The present updated network meta-analysis will comprehensively answer this question.

ETHICS AND DISSEMINATION

We will communicate our findings through participating in academic conferences or submiting it to be considered for publication in peer reviewed scholar journal.

INPLASY REGISTRATION NUMBER

We registered this protocol in International Plateform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) platform and obtained an identifier of INPLASY2020110043 (https://inplasy.com/inplasy-2020-11-0043/).

Platelet-Rich Plasma Versus Hyaluronic Acid in the Treatment of Knee Osteoarthritis: A Meta-analysis of 26 Randomized Controlled Trials

PURPOSE

To compare the effectiveness and safety of platelet-rich plasma (PRP) and hyaluronic acid (HA) in patients with adult knee osteoarthritis (KOA) and to explore the most effective and safe protocol by using a meta-analysis method.

METHODS

This study was based on Cochrane methodology for conducting a meta-analysis. Only randomized controlled trials with an experimental group that used PRP and a control group that received HA were eligible for this study. The participants were adults who had KOA. The outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the visual analog scale (VAS), the EuroQol VAS, the International Knee Documentation Committee, the Tegner score, the Lequesne Scale, the Knee injury Osteoarthritis Outcome Score, satisfaction rate, and adverse events. Subgroup analyses was performed for patients with different doses, types, and times of PRP interventions and grades of OA. The Review Manager Database was used to analyze the included studies.

RESULTS

Twenty-six randomized controlled trials involving 2430 patients were included. The WOMAC total scores, WOMAC physical function scores, and VAS scores of the PRP group were better than the those of the HA group at 3, 6, and 12 months. The PRP group had better WOMAC pain, WOMAC stiffness, EuroQol VAS, and International Knee Documentation Committee scores than the HA group at 6 and 12 months. There was no significant difference in adverse events between the 2 groups (relative risk 1.21, 95% confidence interval 0.95-1.54; P = .13).

CONCLUSIONS

For the nonsurgical treatment of KOA, compared with HA, intra-articular injection of PRP could significantly reduce patients' early pain and improve function. There was no significant difference in adverse events between the 2 groups. PRP was more effective than HA in the treatment of KOA, and the safety of these 2 treatment options was comparable.

LEVEL OF EVIDENCE

Level I, meta-analysis of Level I RCTs.

Regenerative Injectable Therapies: Current Evidence

Regenerative medicine is a growing field of musculoskeletal treatments that focuses on amplifying the body's natural healing properties to improve function and pain after injury. Regenerative treatments are applied locally at the site of injury and work though different mechanisms, some of which are unexplained at this time. Current evidence demonstrates benefit for certain regenerative treatments, but further standardization of treatments and additional studies are required to provide additional data to support specific regenerative treatments. This review seeks to explore the evidence and discuss appropriate use of the most common regenerative treatments including platelet-rich plasma, prolotherapy, autologous mesenchymal stem cells, human-derived allograft products, and saline.

Leucocyte-poor-platelet-rich plasma intra-operative injection in chondral knee injuries improve patients outcomes. A prospective randomized trial

PURPOSE

Evaluate the effects of intra-operative leucocyte-poor-platelet-rich plasma (PRP) (type P3-Bβ with endogenous activation) injection in International Cartilage Repair Society (ICRS) grade III knee chondral injuries treated by chondroplasties, to increase and ameliorate the repair tissue.

METHODS

Patients were divided into two groups. Group A (control) consisted of 31 patients and Group B (PRP) 33 patients, totaling 64 patients analyzed. Patients also could had associated injuries (meniscal and/or ACL) being equally divided between both groups to avoid bias. PRP was injected at the end of surgery in group B. The patient outcomes were assessed using subjective International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Tegner activity forms, prior to the surgery and three, six, 12, and 24 months after surgery (medium-term follow up).

RESULTS

IKDC and KOOS scores showed increase at each evaluation time points after surgery in both groups, but the treated Group (B) showed a higher increase with statistically significant difference. The Tegner activity scores were higher for the treated group only at six and 12 months.

CONCLUSION

Based on the subjective IKDC, KOOS, and Tegner scores, those patients affected by ICRS grade III chondral injuries undergoing arthroscopic chondroplasty who were also treated with PRP showed better and faster outcomes than the control group. Independently from the associated injury (meniscal or ACL). This difference could be measured for up to two years.

Hyaluronic acid and platelet-rich plasma for the management of knee osteoarthritis

PURPOSE

Symptomatic knee osteoarthritis (OA) remains a substantial cause of pain and disability worldwide and effective management in young patients without indications for total knee arthroplasty remains challenging. Intra-articular injections represent a viable option in the non-operative treatment of knee OA. Hyaluronic acid (HA) and platelet-rich plasma (PRP) are two commonly utilized intra-articular treatment modalities that are of particular clinical interest in the current literature. The purpose of this manuscript is to provide a concise review of the current literature on the use of HA, PRP, and HA-PRP conjugates for the treatment of symptomatic knee OA.

METHODS

A review of the literature utilizing PubMed, OVID/Medline, and Cochrane databases on basic science and clinical literature pertaining to preparation, composition, and outcomes of HA, PRP, and HA-PRP conjugates in patients with symptomatic knee OA.

RESULTS

Both HA and PRP have been shown to be efficacious for the treatment of symptomatic knee OA, with HA injections providing limited short-term improvement, while PRP may provide greater therapeutic relief, particularly with the use of leukocyte-poor (LP-PRP) formulations. Despite limited data, the combination of different formulations of HA-PRP conjugates may provide a synergistic effect, resulting in a clinically significant improvement in both pain and function.

CONCLUSION

In patients with symptomatic knee OA, intra-articular HA and PRP provide short-term improvement in pain and function, while the efficacy of HA-PRP conjugates warrants further study.

Platelet-rich plasma versus hyaluronic acid in the treatment of knee osteoarthritis: a meta-analysis

Background

This study aimed to evaluate the clinical efficacy of platelet-rich plasma (PRP) injection compared with hyaluronic acid (HA) injection for patients undergoing knee osteoarthritis.

Methods

We systematically searched electronic databases including PubMed, Embase, Web of Science, and the Cochrane Library on January 23, 2020 to identify relevant studies issued in English languages. The outcomes evaluating the efficacy of knee osteoarthritis (KOA) treatment were Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores (WOMAC pain, function, stiffness, and total scores) at 1, 3, 6, and 12 months; International Knee Documentation Committee (IKDC) scores, Lequesne Index score, Visual Analog Scale (VAS) scores, EQ-VAS scores, and KOOS scores. The pooled data were analyzed by Stata 12.0.

Results

A total of 20 RCTs were enrolled in the present meta-analysis. The pooled results demonstrated that platelet-rich plasma (PRP) injection reduced pain more effectively than hyaluronic acid (HA) injection at 6-month and 12-month follow-up evaluated by WOMAC pain scores and VAS scores. EQ-VAS in the patients treated with PRP injection was lower than that in patients with HA injection at 12 months. Moreover, the patients with PRP injection had a better function recovery than those with HA injection at 1-month, 3-month, 6-month, and 12-month follow-up, as evaluated by WOMAC function scores. WOMAC total scores showed significant difference at 6-month and 12-month follow-up. The IKDC scores indicated PRP injection was significantly more effective than HA injection at 3 months and 6 months. However, the Lequesne Index scores, KOOS scores, and adverse events did not show any significant difference between groups.

Conclusion

Intra-articular PRP injection appeared to be more efficacious than HA injection for the treatment of KOA in terms of short-term functional recovery. Moreover, PRP injection was superior to HA injection in terms of long-term pain relief and function improvement. In addition, PRP injection did not increase the risk of adverse events compared to HA injection.

Intraosseous infiltrations of Platelet-Rich Plasma for severe hip osteoarthritis: A pilot study

OBJECTIVE

Addressing the subchondral bone through intraosseous infiltrations of Platelet-Rich Plasma (PRP) may improve the effectiveness of this technique for severe hip osteoarthritis (HOA).

METHODS

Forty patients with HOA degree 2 and 3 according to the Tönnis scale were recruited for this study. They were susceptible to a total hip arthroplasty, without response to previous treatment based on intraarticular infiltrations of PRP. Patients received a combination of intraosseous injections into the acetabulum and the femoral head, as well as intraarticular PRP infiltrations. The clinical outcome was evaluated at 2, 6 and 12 months using the Hip Osteoarthritis Outcome Score (HOOS) and the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index.

RESULTS

At 2, 6 and 12 months, patients had significant pain improvement according to HOOS pain, WOMAC pain, and VAS scores. After the treatment, the percentage of patients with minimal clinically important improvement was 40% (16 over 40 patients) at 2 months, 37.5% (15 over 40) at 6 months, and 40% (16 over 40) at 12 months. Conclusion: The combination of intra-articular and intra-osseous infiltrations of PRP showed a pain reduction and improvement in hip joint functionality up to 12 months in patients with severe HOA, with no severe adverse effects.

The Clinical Use of Platelet-Rich Plasma in Knee Disorders and Surgery-A Systematic Review and Meta-Analysis

In recent years, the interest in biological treatment of knee lesions has increased, especially the application of platelet-rich plasma is of particular note. The number of articles evaluating platelet-rich plasma (PRP) efficacy in the recovery of knee disorders and during knee surgery has exponentially increased over the last decade. A systematic review with meta-analyses was performed by assessing selected studies of local PRP injections to the knee joint. The study was completed in accordance with 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A multistep search of PubMed, Embase, Cochrane Database of Systematic Reviews, and Clinicaltrials.gov was performed to identify studies on knee surgery and knee lesion treatment with PRP. Of the 4004 articles initially identified, 357 articles focusing on knee lesions were selected and, consequently, only 83 clinical trials were analyzed using the revised Cochrane risk-of-bias tool to evaluate risk. In total, seven areas of meta-analysis reported a positive effect of PRP. Among them, 10 sub-analyses demonstrated significant differences in favor of PRP when compared to the control groups (p < 0.05). This study showed the positive effects of PRP, both on the recovery of knee disorders and during knee surgery; however further prospective and randomized studies with a higher number of subjects and with lower biases are needed.

Autologous Biologic Treatment with Fat, Bone Marrow Aspirate and Platelet Rich Plasma Is an Effective Alternative to Total Knee Arthroplasty for Patients with Moderate Knee Arthrosis

Background: Osteoarthrosis (OA) of the knee afflicts millions worldwide. Total Knee Arthroplasty (TKA) is common, but associated with substantial cost and morbidity. Prior studies of intra-articular injection of fat, bone marrow aspirate (BMA), and platelet rich plasma (PRP) have shown clinical benefit. We hypothesized that injection of autologous adipose tissue, BMA, and PRP would provide significant benefit for patients with moderate knee OA resulting in avoidance of total knee arthroplasty (TKA) in most, with discontinuance of NSAIDs and other drugs. Methods: 42 TKA candidate patients (47 knees) with moderate (Kellgren-Lawrence 2 and 3) knee OA who had failed conservative treatment had autologous adipose tissue, BMA, and PRP injection as an alternative to TKA in office using only local anesthetic. Patients had discontinuance of all nonsteroidal anti-inflammatory medicines (NSAIDs) and other analgesics, except acetaminophen, prior to treatment. Patients were evaluated with Knee injury and Osteoarthritis Outcome Score Physical Shortform (KOOS-PS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Single Assessment Numeric Evaluation (SANE) prior to treatment, and at 6 months, 1, and 2 years after treatment. Results: Follow up exceeded 80% at all time points. There were no significant adverse events. TKA was avoided in 97% at one and 86% at two years after treatment. Mean SANE, KOOS-PS, and WOMAC scores significantly improved at 6 months, 1, and 2 years post-treatment. WOMAC and SANE scores were higher at two versus one year post-treatment. Conclusions: Combined fat, BMA, and PRP injection is a safe and effective treatment for moderate knee OA, with reliable avoidance of TKA and possible continued improvement at two year follow-up.

Histopathologic Evaluation of the Effects of Intraurethral Platelet Rich Plasma in Urethral Trauma Experimentally Induced in Rat Model

OBJECTIVE

To determine the efficacy of platelet rich plasma applied early initialization after urethral trauma for preventing inflammation and spongiofibrosis.

MATERIALS AND METHODS

Twenty-three rats were randomized and divided into 3 groups, with 10 rats in 2 groups. Only sham group had 3 rats. The urethras of all rats were traumatized with a pediatric urethrotome knife at 6- and 12-o'clock. For 15 days, group I was given platelet rich plasma (PRP) once a day without urethral injury (sham group), group II (n = 10) was not given any medical treatment only urethral injury group (UI-PRP), group III (n = 10) was given PRP once a day intraurethrally as instillation using a 22 ga catheter sheath with urethral injury (UI+PRP). On day 15, the penises of the rats were degloved to perform penectomy.

RESULTS

A significant difference was detected in all parameters when the sham, UI-PRP, UI+PRP groups were compared (respectively, P = .001, / <.001, / .008 / .007) and a significant difference was observed among mucosal inflammation, fibrosis, and edema parameters when UI-PRP and UI+PRP groups were compared. (Respectively; P <.001, / <.001 / .006).

CONCLUSION

In this study, it was shown that intraurethral PRP applied after urethral trauma significantly decreased mucosal inflammation, spongiofibrosis, and edema. Depending on the results we acquired in this study, we think that PRP may be a promising option in urethral stricture treatment.

Platelet-Rich Plasma for Sport-Active Patients with Knee Osteoarthritis: Limited Return to Sport

Objective

To evaluate a cohort of sport-active patients suffering from cartilage degeneration and OA, in terms of clinical outcome and return to sport (RTS) after platelet-rich plasma (PRP) injective treatment.

Design

This study included forty-seven sport-active patients ≤50 years old with unilateral symptomatic knee cartilage degeneration or OA. Patients received 3 PRP injections and were prospectively evaluated at baseline and then at 2, 6, 12, and 24 months follow-up by IKDC subjective EQ-VAS, and Tegner scores. Furthermore, patients were asked about their RTS, in terms of return to any sport level or to their activity level before symptoms onset.

Results

IKDC subjective score improved significantly at all follow-ups, changing from 59.2 ± 13.6 to 70.6 ± 13 at 12 months and to 76.7 ± 12.5 at 24 months (p < 0.0005). A similar outcome was observed with the EQ-VAS score. Tegner score improved from 3.6 ± 1.4 to 4.8 ± 0.9 at 24 months (p < 0.0005). A similar outcome was observed with the EQ-VAS score. Tegner score improved from 3.6 ± 1.4 to 4.8 ± 0.9 at 24 months (p < 0.0005). A similar outcome was observed with the EQ-VAS score. Tegner score improved from 3.6 ± 1.4 to 4.8 ± 0.9 at 24 months (p < 0.0005). A similar outcome was observed with the EQ-VAS score. Tegner score improved from 3.6 ± 1.4 to 4.8 ± 0.9 at 24 months (

Conclusions

Sport-active patients affected by knee OA can benefit from PRP injections, with pain and function improvement over time. However, results are less satisfactory in terms of RTS since only half can achieve the same sport level as before the onset of symptoms. Patients undergoing PRP treatment should be made aware of their low chances to go back to high-impact sport activities.