The efficacy of platelet-rich plasma in the treatment of symptomatic knee osteoarthritis: a systematic review with quantitative synthesis

Efficacy of Intraoperative Platelet-Rich Plasma After Meniscal Repair: Systematic Review and Meta-analysis

Background

Meniscal injuries frequently require surgical intervention to restore knee joint function and stability. Intraoperative platelet-rich plasma (PRP) injection has emerged as a potential adjunctive therapy to enhance tissue healing post-meniscal repair. This systematic review and meta-analysis aimed to evaluate the efficacy of PRP in terms of pain relief, functional recovery, and overall success rates in patients undergoing meniscal repair procedures.

Methods

A comprehensive search strategy was employed to identify relevant studies across Scopus, PubMed, Embase, and the Cochrane Library databases. The inclusion criteria encompassed human studies, including randomized controlled trials (RCTs), cohorts, and case-control studies, focusing on intraoperative platelet-rich plasma (PRP) use post-meniscal repair and reporting outcomes related to pain, functionality, and cure rates. Exclusion criteria comprised animal studies, non-English publications, studies lacking relevant outcome measures, and those with insufficient data. Two reviewers independently screened titles and abstracts, resolving disagreements through consensus or consultation with a third reviewer, followed by a full-text assessment for potentially eligible studies. Data extraction was conducted independently by two reviewers using a standardized form. The reliability of observational studies was evaluated using the Newcastle-Ottawa Scale. Subgroup analyses and pooled effect estimates for main outcomes were computed using RevMan 5.3, a meta-analysis tool.

Results

The demographic analysis revealed that the PRP group had an average age of 41.39 years, while the control group had an average age of 42.1 years. In terms of gender distribution, the PRP group consisted of 61 men and 29 women, while the control group had 62 men and 34 women. Pain ratings showed a preference for PRP with a mean difference of 4.83 (p = 0.13). However, there was no significant difference in Lysholm scores (mean difference: - 0.44, p = 0.91) or IKDC scores (mean difference: 2.80, p = 0.14) between the PRP and control groups. Similarly, ROM measures did not show a statistically significant difference, with a mean difference of 2.80 (p = 0.18). Additionally, there was no significant distinction in failure rates between the PRP and control groups, as indicated by a weighted mean difference of 0.71 (p = 0.52). These findings suggest that while PRP may offer some benefits in pain relief, its impact on functional recovery, range of motion, and failure rates following meniscal repair procedures is inconclusive.

Conclusion

The current evidence regarding the effect of intraoperative platelet-rich plasma (PRP) injection on patients undergoing meniscal repair remains inconclusive. While some studies suggest potential benefits in terms of pain relief and functional recovery, others show no significant differences compared to control groups. The impact of PRP therapy on overall success rates, including rates of re-tear and revision surgery, is also uncertain. Further well-designed randomized controlled trials with larger sample sizes are needed to provide more robust evidence and guide clinical practice in orthopedic surgery.

The effect of intra-articular ozone injection combined with home-based exercise on pain and function in daily living activities of patients with mild to moderate knee osteoarthritis, a randomized double-blinded controlled clinical trial

BACKGROUND

Knee osteoarthritis is the most common arthritis. Various treatments such as analgesics, exercise therapy, and surgery in high-grade OA have been shown to reduce pain and improve patients' function; however, determining the optimal treatment remains a challenge. Ozone therapy is one of the injection techniques used for symptom relief in these patients. Therefore, this study aimed to evaluate the effect of ozone injection in mild to moderate knee osteoarthritis.

METHODS

Thirty-three patients with grade II-III knee osteoarthritis based on the Kellgren-Lawrence classification were involved in the study, by block randomisation. Totally 42 knees were included. All patients received exercise therapy, 500 mg of acetaminophen tablets (up to 2 g per day as needed), and healthy nutrition. In a double-blinded method, the intervention group received Ozone injections, but the control group received placebo injections. Functional tests, including timed-up-and-go and 6-min walk tests, were assessed at baseline and immediately after the 6-week intervention. In addition, the pain was measured by VAS score, and stiffness and activity of daily living (ADL) were evaluated by KOOS questionnaire before and after a 6-week intervention and then one and six months afterwards.

FINDINGS

Improvements in pain and KOOS scores were seen in both groups in the 6th week of injections (p < 0.05), with significant differences between groups. However, the effects on pain and KOOS scores disappeared in the 1st and 6th months of follow-ups in the control group. Nevertheless, the effects persisted in the intervention group compared to the baseline and control group, which means that in the mentioned time points intervention group showed significant improvement compared to the control group (p < 0.05). In addition, functional tests showed significant differences between the two groups in the 6th week of injections (p < 0.001).

INTERPRETATION

Ozone injection is a non-surgical treatment for mild to moderate knee osteoarthritis that could decrease pain and improve function and ADL of patients in the short to mid-term (3-6 months), so it seems that adding Ozone injection to the routine exercise therapy in management of patients with knee OA could improve outcomes.

Platelet-Rich Plasma for Knee Osteoarthritis: What Does the Evidence Say?

The utilization of platelet-rich-plasma as a therapeutic intervention for knee osteoarthritis has gained immense attention since 2008. The increase in the number of scientific publications dedicated to this area can be attributed to the majority of favorable results reported in clinical trials and basic science studies. However, despite the growing evidence, the use of platelet-rich plasma in clinical practice still poses controversial aspects. The potential mechanisms of action described for platelet-rich-plasma so far indicate that it could serve as a disease-modifying drug, acting to counteract important aspects of knee osteoarthritis pathophysiology (cartilage breakdown, inflammation, and bone remodeling). Nevertheless, its efficacy in slowing down the progression of knee osteoarthritis remains unproven. While inconsistencies have been noted, the majority of controlled clinical trials and meta-analyses advocate for the utilization of platelet-rich-plasma in treating knee osteoarthritis, as it has demonstrated greater efficacy than hyaluronic acid and placebo, with a follow-up of at least 1 year. Despite advancements made in certain areas, significant diversity persists regarding the formulations used, therapeutic regimen, extended follow-up periods, patient selection, and assessment of clinically relevant outcomes. Consequently, the leading clinical practice guidelines do not recommend its use. In light of the emerging evidence, this narrative review aims to provide an objective evaluation of the recent available scientific literature (last 5 years) focused on randomized clinical trials and meta-analyses to present a current overview of the topic.

Impact of changes in clinical practice guidelines for intra-articular injection treatments for knee osteoarthritis on public interest and social media

OBJECTIVE

To summarize changes in recommendations for injection treatments for knee osteoarthritis (OA) in current clinical practice guidelines (CPGs) and to assess whether these changes have affected public interest according to Google data and content in YouTube videos.

DESIGN

A literature search to identify CPGs revised since 2019 that provide recommendations regarding the five intra-articular injection treatments for knee OA (corticosteroid [CS], hyaluronic acid [HA], stem cell [SC], platelet-rich plasma [PRP], and botulinum toxin [BT]) was conducted to assess perspective changes for each treatment. Data from Google Trends were examined to identify changes in search volume from 2004 to 2021 using a join-point regression model. Relevant YouTube videos were divided into those uploaded before and after changes in CPGs and compared according to degrees of recommendation for each treatment to identify the effect of changes in CPGs on video production.

RESULTS

All eight identified CPGs released after 2019 recommended HA and CS use. Most CPGs were the first to state a neutral or opposing stance concerning the use of SC, PRP, or BT. Interestingly, relative searches on Google for SC, PRP, and BT has increased greater than those for CS and HA. YouTube videos produced after CPGs changed continue to recommend SC, PRP, and BT as much as those produced before CPGs were revised.

CONCLUSIONS

Although knee OA CPGs have changed, public interest and healthcare information providers on YouTube have not reacted to this shift. Improved methods to propagate updates to CPGs warrant consideration.

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.

A comparative study of the efficacy of intra-articular injection of different drugs in the treatment of mild to moderate knee osteoarthritis: A network meta-analysis

BACKGROUND

Knee osteoarthritis (KOA) has a high clinical prevalence and frequently interferes with patients normal lives. In KOA patients, evidence suggests that intra-articular (IA) injection improves joint function and decreases discomfort. Several IA injection treatments are used in daily practice to improve symptomatic control of knee osteoarthritis, but their efficacy is frequently disputed.

METHODS

This network meta-analysis compares the efficacy of different IA injections for mild to moderate knee osteoarthritis. Seven databases (PubMed, EMBASE, Web of Science, Cochrane Library, China Biology Medicine disc, WanFang, and China National Knowledge Infrastructure) were searched for randomized controlled trials published up to and including December 20, 2021, and final follow up indicators were used. Visual analogue scale (VAS) score and The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index (WOMAC) score change from baseline were the primary outcomes. We used the Cochrane risk of bias tool to assess the quality and risks of biases of papers. We calculated the weighted mean difference (WMD) and 95% confidence interval (CI) for each outcome. State (Version 15.1, Texas, USA) and SPSS (Version 20, Chicago, USA) was used in all statistical analyses, and Review Manager (version 5.4) was used in assessing the risks of biases.

RESULTS

Our study included 16 randomized controlled trials with a total of 1652 patients. platelet-rich plasma (PRP) IA injection therapy had the highest likelihood of being the best intervention in reducing WOMAC pain (surface under the cumulative ranking area [SUCRA] 84.7%), stiffness (SUCRA 95.1%), and function (SUCRA 98.5%) scores, according to the SUCRA. The best measures for lowering the WOMAC total and VAS scores were IA injection platelet-rich plasma-derived growth factor (SUCRA 84.9%) and hyaluronic acid and platelet-rich plasma (SUCRA 84.9%). In the VAS score group, PRP outperformed hyaluronic acid (HA) (WMD 1.3, 95% CI 0.55-2.55) and corticosteroids (CS) (WMD 4.85, 95% CI 4.02-5.08), according to the forest map results. PRP also outperformed CS (WMD 14.76, 95% CI 12.11-17.41), ozone (WMD 9.16, 95% CI 6.89-11.43), and PRP + HA (WMD 2.18, 95% CI 0.55-3.81) in the WOMAC total score group. Furthermore, PRP outperforms other drugs in terms of reducing WOMAC function, stiffness, and function score.

CONCLUSION

In patients with mild to moderate KOA, IA injection PRP outperformed IA injection ozone, HA, CS, platelet-rich plasma-derived growth factor, and hyaluronic acid and platelet-rich plasma in terms of pain, stiffness, and dysfunction.

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.

Comparison of the clinical effectiveness of activated and non-activated platelet-rich plasma in the treatment of knee osteoarthritis: a systematic review and meta-analysis

INTRODUCTION/OBJECTIVES

Platelet-rich plasma (PRP) has shown to be clinically effective in the treatment of knee osteoarthritis (OA). Notwithstanding, some inconsistences remain due to methodological differences in PRP preparation such as the use (or not) of activation strategies. We aimed to evaluate whether the use of non-activated PRP would be as effective as activated PRP in patients with knee OA.

METHOD

All randomized, placebo-controlled trials were identified through a search in MEDLINE, EMBASE, Scopus, and Web of Science up to June 2022. Pre- and post-injection pain and function scores were collected. The meta-analysis was conducted with a random-effects model and generic inverse variance method. Effect sizes were estimated using standardized mean differences (SMD).

RESULTS

Fourteen clinical trials involving 1292 subjects were included for meta-analysis. Exogenous activation of PRP revealed a significant pain relief (SMD, - 1.05 [95% CI - 1.58 to - 0.52]; p = 0.0001) and a significant functional improvement (SMD, - 1.21 [95% CI - 1.75 to - 0.67]; p < 0.0001) unlike studies describing the use of a non-activated PRP. The sensitivity analysis indicated that the effect size for both outcomes was not influenced by a single study.

CONCLUSIONS

The results of this systematic review suggest that the use of an exogenously activated PRP is more effective in improving both pain and functional scores in patients with knee OA. Key Points • Results from meta-analysis suggest that exogenously activated PRP is clinically more effective than non-activated PRP. • The use of an activated PRP was more frequently reported by the included studies. • The most frequent method for activation was the use of calcium chloride (CaCl₂).

Thermosensitive In Situ Gels for Joint Disorders: Pharmaceutical Considerations in Intra-Articular Delivery

The intra-articular administration of conventional drug solutions or dispersions in joint diseases such as osteoarthritis has a relatively short retention time and, therefore, limited therapeutic effect. Thermosensitive polymer solutions that exhibit a sol-gel phase transition near body temperature after injection can prolong drug retention by providing a depot from which the drug release is sustained while relieving inflammation and preventing degradation of the joint complex. Thermosensitive hydrogels have in recent times garnered considerable attention in the intra-articular therapeutics of joint diseases such as osteoarthritis. Among the stimuli-responsive gelling systems, most research has focused on thermosensitive hydrogels. These gels are preferred over other stimuli-sensitive hydrogels since they have well-controlled in situ gelling properties and are also easier to load with drugs. Temperature-sensitive polymers, such as block copolymers or poloxamers, are frequently used to modify their gelation properties, usually in combination with other polymers. They are compatible with most drugs but may pose formulation challenges in terms of their low-response time, highly fragile nature, and low biocompatibility. The stability and biodegradability of implant hydrogels can control the drug release rate and treatment efficacy. This review stresses the application of thermosensitive gels in joint disorders and summarizes recent developments for intra-articular application, including the incorporation of nanoparticles. The hydrogel composition, drug release mechanisms, and the challenges involved in their formulation and storage are also discussed.

Mesenchymal stem cells-derived microvesicles versus platelet-rich plasma in the treatment of monoiodoacetate-induced temporomandibular joint osteoarthritis in Albino rats

Temporomandibular joint osteoarthritis (TMJ-OA) is a serious disease, designated by severe joint pain and dysfunction. Limitations of current therapeutics have led to an increased interest in regenerative strategies. Recently, the non-surgical treatment of OA has seen increased use of biologic injectable therapies like mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP). Although these biotherapies represent an admirable effort, more studies are necessary to determine their efficacy. Thus, the aim of this study was to assess the curative potential of a single intra-articular injection of bone marrow MSCs-derived microvesicles (BM-MSCs-MVs) versus a single intra-articular injection of PRP in monoiodoacetate (MIA)-induced TMJ-OA model in Albino rats. Forty-eight male rats were used. A single intra-articular unilateral MIA injection was utilized to induce TMJ-OA. One week post induction, rats were sorted into 3 groups (16 rats each): group (I): received no treatment, groups (II) & (III): received BM-MSCs-MVs and PRP respectively. Scarification was done at 2 and 4 weeks from onset of treatment. Histological changes of the condylar TMJ were examined with H&E staining. Expression of IL-1β, TNF-α, NF-κB, MMP-13, MMP-3, and collagen ΙΙ markers was detected using real-time PCR. Histologically, the osteoarthritic group exhibited degenerated condylar tissues which were aggravated at 4 weeks. Oppositely, a marked improvement in the condylar TMJ histology was noticed in both the BM-MSCs-MVs-and PRP-treated groups at both time intervals. Additionally, the treated groups showed a decrease in IL-1β, TNF-α, NF-κB, MMP-13 and MMP-3 and an increase in collagen ΙΙ genes expression in contrast to the untreated group. Moreover, this difference was significant in the BM-MSCs-MVs group as compared to the PRP-treated group. Our results concluded that BM-MSCs-MVs as well as PRP treatments were able to target the key pathological features in OA, mainly inflammation and matrix degradation, and helped in restoring condylar structure in TMJ-OA rat model. However, BM-MSCs-MVs treatment exhibited more efficient therapeutic potential as compared to PRP treatment.

Comparative Study of the Efficacy of Hyaluronic Acid, Dry Needling and Combined Treatment in Patellar Osteoarthritis-Single-Blind Randomized Clinical Trial

Background: Osteoarthritis of the knee is one of the most common ailments worldwide, and pain management of this condition is critical. Methods: A multicentre randomized controlled trial RCT with three months of follow-up, conducted in parallel groups: hyaluronic acid (HA), dry needling (DN) and ultrasound (US) and isometrics of quadriceps. 60 participants took part in the RCT who were diagnosed with osteoarthritis (Grade 3) of the knee by MRI and active adults (age: 23.41 ± 1.68 years; height: 1.79 ± 0.08 m; body mass: 78.33 ± 9.03 kg; body mass index (BMI): 24.14 ± 1.45 kg/m²). After the assigned intervention, VAS, WOMAC, IPAQ and the Star Excursion Balance test were measured at baseline. At 24 h, 15 days, 30 days, 90 days and 180 days follow-up, all variables were measured again. Results: Comparing statistically significant differences between groups, VAS scores were significant at post-test measurement (HA vs. US + isometric and DN vs. US + isometric) at 24 h (HA vs. DN), at 15 days (HA vs. US + isometric and DN vs. US + isometric) and at 1 month (US + isometric vs. HA and US + isometric vs. DN). Conclusions: There is an improvement in pain intensity in knee osteoarthritis in the short term in patients undergoing DN and conventional US + isometric treatment, but in the long term the HA group shows an improvement in pain intensity. There is also a significant difference in the improvement of knee function at different phases of the study in the various intervention groups. The combination of DN and HA in clinical practice is the best option for the treatment of osteoarthritis.

Bibliometric analysis of the top 50 highly cited articles on platelet-rich plasma in osteoarthritis and tendinopathy

The primary goal of this study was to compile the top 50 most cited articles on the use of platelet-rich plasma (PRP). A search of relevant studies was performed in accordance with the PRISMA guidelines in Web of Science. The top 25 most cited articles in osteoarthritis and tendinopathy were then compiled and evaluated. Level 1 evidence articles constituted the majority of the studies (64%) and were more likely to have a higher citation density. Altmetric data was highest for level 1 systematic reviews. Of the articles that report a positive outcome for PRP, 13% (2/16) had low risk of bias. This study defines the most cited and influential publications regarding PRP to further research in this area.

Thermal Oscillation Changes the Liquid-Form Autologous Platelet-Rich Plasma into Paste-Like Form

Objectives

The texture of the autologous platelet-rich plasma (PRP) that is used in treating degenerative joint diseases such as knee osteoarthritis (OA) is usually in liquid form. However, the turnover rate of protein metabolism in the knee synovial fluid (SF) is less than one hour. This study examined the feasibility of the thermal oscillation technique in converting the liquid-form PRP into an injectable viscous paste-like PRP that may delay the degradation of PRP and continuously release growth factors in the knee joint for a longer period of time.

Methods

This study was conducted in the rehabilitation department of a tertiary hospital. A total of 10 elderly patients with an average age of greater than 65 years and diagnosed with moderate degree of knee OA were recruited. The RegenPRP (RegenLab, Le Mont-sur-Lausanne, Switzerland) test tube chamber was used for PRP generation. A total of 60 milliliters (mL) of blood was drawn from each patient. 10 mL of blood was injected into each PRP test tube chamber. As a result, a total of 6 test tube chambers were obtained and each chamber was centrifuged for 15 minutes. Approximately 5 mL of PRP supernatant (the liquid-form end product) was aspirated and sent for thermal oscillation treatment. Five temperatures were tested: 55, 65, 75, 85, and 95 degrees Celsius. Oscillation was set at 200 revolutions per minute (rpm) for 15 minutes. The enzyme-linked immunosorbent assay (ELISA) was applied in measuring the concentration of platelet-derived growth factor (PDGF) in picogram/milliliter (pg/mL). Repeated measures ANOVA followed by the Bonferroni post hoc test was used to compare the PDGF concentrations between each testing condition.

Results

Under 75 degrees Celsius of heating, the resultant paste-like PRP end product had the highest concentration of PDGF in picograms per milliliter (pg/mL) as compared with other heating conditions (p < 0.05). The viscosity of the paste-like PRP was measured to be 70,000 centipoise (cP), which is similar to the viscosity of a toothpaste. The paste-like PRP end product was able to release PDGF continuously for about 14 days, with the highest concentration achieved on the 8^th day with an average of 35646 ± 2499 pg/mL. In nonthermally treated liquid-form PRP sample, the highest number of PRP was observed on the 4^th day with an average value of 8444 ± 831 pg/mL. Under the heating conditions of 55 and 95 degrees Celsius, the highest concentration of PDGF was observed on the 5^th day (13346 ± 764 pg/mL and 3440 ± 303 pg/mL, respectively). Under the heating conditions of 65 and 85 degrees Celsius, the highest concentration of PDGF was observed on the 7^th day (15468 ± 744 pg/mL and 20432 ± 1118 pg/mL, respectively).

Conclusion

Through thermal oscillation, liquid-form PRP can be converted to paste-like PRP end product with a viscosity similar to that of a toothpaste. The best heating condition was discovered to be 75 degrees Celsius. The paste-like PRP was able to release PDGF continuously for about 2 weeks, with the highest concentration obtained on the 8^th day. The findings in this study suggested that paste-like PRP may be a viable option in treating degenerative knee joint diseases.

Intra-articular injection with platelet-rich plasma compared to triamcinolone hexacetonide or saline solution in knee osteoarthritis: A double blinded randomized controlled trial with one year follow-up

OBJECTIVES

To compare the effectiveness of intra-articular injection (IAI) of Platelet-Rich Plasma (PRP) with Triamcinolone Hexacetonide (TH) and Saline Solution (SS), in patients with knee osteoarthritis (OA).

DESIGN

A randomized controlled trial, with blinded patients and assessor.

SETTING

Outpatient rheumatology service.

SUBJECTS

Patients with knee osteoarthritis grades II and III.

INTERVENTIONS

Patients received IAI with PRP, 40 mg TH, or SS.

METHODS

Patients were assessed at baseline and after 4, 8, 12 e 52 weeks with: visual analogue scale (VAS) for pain at rest and movement, WOMAC questionnaire, Timed to Up and Go test, 6-min walk test, percentage of improvement, goniometry, quality of life SF-36 questionnaire, Likert scale and Kelgreen & Lawrence (KL) radiographic scale (only at baseline and 52 weeks).

RESULTS

100 patients were studied, with a mean age of 67.13(6.56) years. The TH group was superior for: percentage of improvement (versus SS group from 4 to 52 weeks); WOMAC total and pain (versus PRP group at 4 weeks); and WOMAC stiffness (versus SS group at 12 weeks). The SS group was inferior for WOMAC function (from 8 to 52 weeks). The PRP group showed lowest radiographic progression [TH 17 (51.51%) to 24 (72.72%); SS 17 (51.51%) to 30 (90.90%); PRP 20 (58.82%) to 21 (61.76%)].

CONCLUSION

The Triamcinolone Hexacetonide group was superior for percentage of improvement and WOMAC, pain and stiffness. For the WOMAC function, the Platelet-Rich Plasma group and Triamcinolone Hexacetonide group were superior to the Saline group. The Platelet-Rich Plasma group showed the lowest radiographic progression at 52 weeks of follow-up.

The Effect of Leukocyte Concentration on Platelet-Rich Plasma Injections for Knee Osteoarthritis: A Network Meta-Analysis

BACKGROUND

It is hypothesized that leukocyte-poor (LP) platelet-rich plasma (PRP) is preferred over leukocyte-rich (LR) PRP for the treatment of knee osteoarthritis (OA).

METHODS

The MEDLINE, Embase, and Cochrane databases were reviewed for all English-language studies comparing LP-PRP or LR-PRP with relevant controls or each other. The follow-up periods were 6 months and 12 months. The primary outcome measure was the change in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between baseline and follow-up. The secondary outcome measures were changes in the WOMAC pain subscale, visual analog scale (VAS) for pain, and International Knee Documentation Committee (IKDC) subjective score between baseline and follow-up, and the incidence of local adverse reactions. Treatment outcomes were analyzed using the mean difference between treatments for continuous outcomes and the odds ratio for binary outcomes, with 95% credibility intervals. Treatment modalities were ranked using the surface under the cumulative ranking (SUCRA) probabilities. Risk of bias was assessed using the relevant Cochrane tools, RoB 2 (version 2 of the Cochrane risk-of-bias tools) for randomized controlled trials (RCTs) and ROBINS-I (Risk of Bias in Non-Randomized Studies - of Interventions) for prospective comparative studies (PCSs).

RESULTS

This network meta-analysis included 23 studies: 20 RCTs and 3 PCSs, with a total of 2,260 patients and a mean follow-up period of 9.9 months. The overall risk-of-bias assessment of the RCTs revealed that 9 studies had low risk, 7 had some concerns, and 4 had high risk. The overall risk-of-bias assessment of the PCSs revealed that 1 study had low risk and 2 had moderate risk. We found no significant (p < 0.05) difference in all outcome measures and local adverse reactions between LP-PRP and LR-PRP. SUCRA rankings revealed that, for all outcome measures, LP-PRP is preferred to LR-PRP across follow-up periods.

CONCLUSIONS

Leukocyte concentration of PRP does not play a significant role in patient-reported outcome measures for knee OA. LP-PRP is preferred to LR-PRP according to SUCRA rankings, but this preference may not be important in clinical practice.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

The Effectiveness of Single Injection of Platelet-Rich Plasma for Knee Osteoarthritis Combined with Meniscus Injury: A Randomized Trial

Objectives : To explore the effectiveness of single injection of platelet-rich plasma with rehabilitation therapy for knee osteoarthritis combined with meniscus injury. Methods : Forty patients who met the inclusion criteria were randomly assigned to a rehabilitation group (REH group, 20 cases) receiving rehabilitation training, and a platelet-rich plasma group (PRP group, 20 cases) receiving an ultrasound-guided single injection of PRP in combination with rehabilitation training. Rehabilitation training in the two groups lasted for 2 weeks, and the patients were evaluated using the short-form McGill pain questionnaire (SF-MPQ), Western Ontario McMaster Universities index (WOMAC score), and infrared thermography (knee-joint mean temperature) before treatment, at 1 week, 1 month and 6 months after treatment. Results : Two patients were lost to follow-up in both the PRP group and the REH group. Significant reductions in pain scores, WOMAC scores and knee temperature were observed at 1 week and 1 month after treatment in both groups (p < 0.05). Significant lower SF-MPQ scores were observed in the PRP group than in the REH group at 6 months followup (p < 0.01). Similarly, the mean knee temperature was significantly lower in the PRP group than in the REH group at 6 months follow-up (p < 0.01). No severe complications occurred in either group. Conclusions: Compared to rehabilitation therapy alone, single injection of platelet-rich plasma in combination with rehabilitation therapy has beneficial effect on pain, knee function and mean knee temperature in patients with KOA combined with meniscus injury. Single injection of platelet-rich plasma combined with rehabilitation therapy has a good short-term effectiveness.

Exosomes derived from platelet-rich plasma administration in site mediate cartilage protection in subtalar osteoarthritis

Subtalar osteoarthritis (STOA) is often secondary to chronic ankle sprains, which seriously affects the quality of life of patients. Due to its etiology and pathogenesis was not studied equivocally yet, there is currently a lack of effective conservative treatments. Although they have been used for tissue repair, platelet-rich plasma-derived exosomes (PRP-Exo) have the disadvantage of low retention and short-lived therapeutic effects. This study aimed to determine whether incorporation of PRP-Exo in thermosensitive hydrogel (Gel) increased their retention in the joint and thereby playing a therapeutic role on STOA due to chronic mechanical instability established by transecting lateral ligaments (anterior talofibular ligament (ATFL)/calcaneal fibular ligament (CFL)). PRP-Exo incorporated Gel (Exo-Gel) system, composed of Poloxamer-407 and 188 mixture-based thermoresponsive hydrogel matrix in an optimal ratio, was determined by its release ability of Exo and rheology of Gel response to different temperature. The biological activity of Exo-Gel was evaluated in vitro, and the therapeutic effect of Exo-Gel on STOA was evaluated in vivo. Exo released from Exo-Gel continuously for 28 days could promote the proliferation and migration of mouse bone mesenchymal stem cells (mBMSCs) and chondrocytes, at the same time enhance the chondrogenic differentiation of mBMSCs, and inhibit inflammation-induced chondrocyte degeneration. In vivo experiments confirmed that Exo-Gel increased the local retention of Exo, inhibited the apoptosis and hypertrophy of chondrocytes, enhanced their proliferation, and potentially played the role in stem cell recruitment to delay the development of STOA. Thus, Delivery of PRP-Exo incorporated in thermosensitive Gel provides a novel approach of cell-free therapy and has therapeutic effect on STOA.

Graphical Abstract

A single intraarticular platelet-rich plasma improves pain and function for patients with early knee osteoarthritis: Analyses by radiographic severity and age

BACKGROUND

Most studies use platelet-rich plasma (PRP) requiring multiple intraarticular injections for knee osteoarthritis (OA).

OBJECTIVE

To investigate the efficacy of a single intraarticular PRP injection for patients with early knee OA and consider subgroup analyses of radiographic severity and age, respectively.

METHODS

Forty-one patients with knee OA (Kellgren-Lawrence grade 1-2) received a single PRP injection into the target knee and were assessed at baseline and 1, 3, and 6 months postinjection. The primary outcome was the mean change from baseline in the visual analog scale (VAS) pain (0-100 mm) at 6 months postinjection. Secondary outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lequesne index, single leg stance test (SLS), use of rescue analgesics and patients' satisfaction.

RESULTS

Thirty-eight patients completed the study. The mean pain VAS decreased significantly from 45.6 ± 13.0 mm at baseline to 16.9 ± 13.4 mm, 14.0 ± 13.1 mm and 15.5 ± 14.0 mm at 1, 3 and 6-month follow-ups (p< 0.001 for all). Significant improvements in WOMAC, Lequesne index, SLS and consumption of analgesics from baseline (p< 0.001 for all) were noted at each follow-up. Patients' satisfaction was high. No serious adverse events occurred. Subgroup analyses revealed that patients with grade 1 OA showed significantly greater VAS pain reduction at 3 months (p= 0.006) and 6 months (p= 0.005) than patients with grade 2 OA. The older-age group (age > 60) showed significantly greater improvements in VAS pain, WOMAC function subscale scores and total scores at 6-month postinjection, compared with the younger age-group (age ≤ 60). The younger-age group reported better satisfaction at 1 and 3-month postinjection.

CONCLUSIONS

One injection of PRP improved pain and function for 6 months for patients with early knee OA. This study supports putting the one-injection regimen into clinical practice. Further research is needed for more definite conclusions.

Platelet-rich plasma outcomes do not correlate with patient satisfaction or perceived cost-effectiveness

BACKGROUND

As platelet-rich plasma injection for knee osteoarthritis (OA) has increased in popularity, it has become more important to assess its effectiveness and satisfaction with its use in the context of its high cost. The purpose of this study was to determine satisfaction, commercial appeal, and effectiveness of platelet-rich plasma (PRP) for the treatment of knee OA.

METHODS

A retrospective review of patients who underwent PRP injection in the knee from 2016 to 2019 was performed. Various patient-reported outcomes were collected, including: satisfaction with the PRP injection (out of 100), whether the patient would want to undergo PRP injection again, whether they would recommend the injection and whether they felt that the injection was worth the cost was collected. VAS pain scores were collected and measured out of 100. Demographics and radiographical information were obtained via chart review. Statistical analyses were conducted including descriptive statistics and binary logistic and linear regressions.

RESULTS

Overall, 114 patients were included. The mean pre-injectionpain score was 70.4, and the mean pain level decreased after injection to 36.8. Patients rated their satisfaction on average as neutral along the aforementioned continuous scale (49.2), , 50.9% stated that they would get the PRP injection again, 60.5% would recommend to a friend, and 50.9% felt the injection was worth the cost. Younger age and improved post-injection pain correlated with increasing likelihood of desiring further PRP injection.

CONCLUSIONS

Patients on average rated satisfaction slightly below average, indicating net neutrality in terms of satisfaction with their injection. Furthermore, only half of the patients indicated that it was worth the cost and that they would receive it again. Younger age and post-injection pain relief increased desire for further injection, but pain-relief did not correlate with patients saying that the injection was worth the cost.

Bone marrow aspirate concentrate versus platelet-rich plasma for treating knee osteoarthritis: a one-year non-randomized retrospective comparative study

Background

Knee osteoarthritis (OA) is a debilitating condition affecting human body biomechanics and quality of life. Current standard care for knee OA leads to trivial improvement and entails multiple adverse effects or complications. Recently, investigational cell therapies injected intra-articularly, such as bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP), have shown safety and therapeutic potency providing patients with pain relief. In the current retrospective comparative study, we investigated the differences in pain and functional improvements in patients with symptomatic knee OA receiving intra-articular injections of BMAC vs PRP.

Methods

Pain and functionality scores were measured at baseline and at different time points post-injection over 12 months, using 3 self-administered, clinically validated questionnaires: the visual analogue scale (VAS) for assessing pain intensity, the knee injury and osteoarthritis outcome score (KOOS) for evaluating functionality and knee-related quality of life, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) for evaluating physical function. The repeated-measures general linear model with Sidak test for pairwise comparisons was used to investigate the influence of the treatment on the score evolution within groups (between baseline and each time point) and between groups (overall).

Results

The BMAC group (n = 26 knees) significantly improved in VAS, KOOS, and WOMAC scores between baseline and 12 months (57.4, 75.88, and 73.95% mean score improvement, respectively). In contrast, the PRP group (n = 13 knees) witnessed nonsignificant improvement in all scores. BMAC, in comparison to PRP, induced significant improvement in outcomes by 29.38% on the VAS scale, 53.89% on the KOOS scale, and 51.71% on the WOMAC scale (P < .002, P < .01, P < .011, respectively).

Conclusions

Intra-articular autologous BMAC injections are safe, effective in treating pain, and ameliorate functionality in patients with symptomatic knee OA to a greater extent than PRP injections.

Graphical abstract

Intra-articular autologous BMAC therapy is safe and provides more relief to patients with symptomatic knee osteoarthritis compared to PRP therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04910-5.

Platelet-Rich Plasma for Rheumatoid Arthritis: A Case Series

Rheumatoid Arthritis (RA) is a chronic disease characterized by severe inflammation that leads to degradation of articular cartilage and the formation of bony erosions. Currently, certain anesthesiologist-led pain management clinics have begun to take on a collaborative role in the treatment of patients with RA, as this progressive disease impairs work capacity due to chronic pain. We present three clinical cases in which platelet-rich plasma (PRP) was used for the treatment of RA in patients seeking a new therapy for pain control and improved range of motion, specifically in certain joints of the hand. The Patient Activity Scale II was employed as a standardized method to assess RA disease severity, recorded on the day of injection, at one month, at three months, and at six months. All of the included patients, ages 49, 60, and 63, had an established diagnosis of RA affecting the proximal interphalangeal and metacarpophalangeal joints of the hand. Over the course of six months, two out of three patients reported a 20% reduction in pain from the initial visit and a 30% improvement in overall well-being. The third patient noted a 50% decrease in pain from the initial visit and a 50% improvement in overall well-being. PRP treatment consistently resulted in functional improvement for each of the three patients treated, while also reducing long term pain and inflammation. Initial clinical and laboratory studies have shown that autologous plasma rich in platelets serves as a source of an abundance of growth factors once activated. The multitude of these growth factors injected into and around the diseased joints improves functionality in patients with RA indicating PRP may be a safe and beneficial therapy in patients with RA primarily affecting the joints of the hand.

Intra-articular injection of Platelet rich plasma versus Hyaluronic acid for moderate knee osteoarthritis. A prospective, double-blind randomized controlled trial on 189 patients with follow-up for three years

Platelet-rich plasma injections have been proposed as an option for Conservative management of knee Osteoarthritis to provide symptomatic relief and also to delay the need for surgical intervention. Although almost all the current literatures provide some evidence on the benefits of this technique compared with Visco- supplementation, no studies have been performed to compare their Clinical outcomes. The purpose is to compare the Clinical outcomes provided by intra- articular injection of either Platelet rich plasma or Hyaluronic acid to treat knee Osteoarthritis. Study Design: Randomized Controlled Trial 200 Patients with a history of Symptomatic knee Osteo- arthritis (Kellgren-Lawrence grade 2 or 3) were randomized to undergo 3 blinded intra-articular in- jections of either Platelet rich plasma or Hyaluronic acid. The Interval between successive injections was 2 weeks. Patients were evaluated prospectively before the injection and then at 2, 6, 12, 24, 30 and 36 months. Evaluation was based on International Knee Documentation Committee (IKDC), Visual analog scale, VOMAC Score and the re- injection rate; 189 patients reached the final evaluation. Both platelet rich plasma and Hyaluronic acid were effective in improving knee Symptoms and functional status over time and remained stable over time up to 18 months Post-injection (No re-injection has been performed to any patient incorporated in this study during the first 18 months). The performed re-injections have been significantly lower in the PRP group. Both platelet rich plasma and Hyaluronic acid were effective in improving knee Symptoms and functional status over time and remained stable over time up to 18 months Post-injection. The rate of the required re-injections has been significantly lower in platelet rich plasma group. platelet rich plasma provide longer duration of symptomatic relief, longer duration of functional status improvement and lesser number of needed re-injections than Hyaluronic acid when the patients have been followed through 36 months.

Bone Marrow Aspirate Concentrate versus Platelet Rich Plasma or Hyaluronic Acid for the Treatment of Knee Osteoarthritis

Background: In the last decade, regenerative therapies have become one of the leading disease modifying options for treatment of knee osteoarthritis (OA). Still, there is a lack of trials with a direct comparison of different biological treatments. Our aim was to directly compare clinical outcomes of knee injections of Bone Marrow Aspirate Concentrate (BMAC), Platelet-rich Plasma (PRP), or Hyaluronic acid (HA) in the OA treatment. Methods: Patients with knee pain and osteoarthritis KL grade II to IV were randomized to receive a BMAC, PRP, and HA injection in the knee. VAS, WOMAC, KOOS, and IKDC scores were used to establish baseline values at 1, 3, 6, 9, and 12 months. All side effects were reported. Results: A total of 175 patients with a knee osteoarthritis KL grade II-IV were randomized; 111 were treated with BMAC injection, 30 with HA injection, and 34 patients with PRP injection. There were no differences between these groups when considering KL grade, BMI, age, or gender. There were no serious side effects. The mean VAS scores after 3, 7, 14, and 21 days showed significant differences between groups with a drop of VAS in all groups but with a difference in the BMAC group in comparison to other groups (p < 0.001). There were high statistically significant differences between baseline scores and those after 12 months (p < 0.001) in WOMAC, KOOS, KOOS pain, and IKDC scores, and in addition, there were differences between these scores in the BMAC group in comparison with other groups, except for the PRP group in WOMAC and the partial IKDC score. There were no differences between the HA and PRP groups, although PRP showed a higher level of clinical improvement. Conclusions: Bone marrow aspirate concentrate, Leukocyte rich Platelet Rich Plasma, and Hyaluronic acid injections are safe therapeutic options for knee OA and provide positive clinical outcomes after 12 months in comparison with findings preceding the intervention. BMAC could be better in terms of clinical improvements in the treatment of knee OA than PRP and HA up to 12 months. PRP provides better outcomes than HA during the observation period, but these results are not statistically significant. More randomized controlled trials and high quality comparative studies are needed for direct correlative conclusions.

Efficacy and Safety of a Single Intra-articular Injection of Platelet-rich Plasma on Pain and Physical Function in Patients With Ankle Osteoarthritis-A Prospective Study

Ankle osteoarthritis (OA) can cause disabling symptoms, and some patients prefer to be treated with minimally invasive procedures. The aim was to evaluate the efficacy and safety of a single intraarticular injection of platelet-rich plasma (PRP) for patients with ankle OA. In a prospective study done in a university-affiliated tertiary care medical center, 44 patients with symptomatic ankle OA for at least 6 months were recruited. Patients received a single injection of PRP (3 mL) into symptomatic ankles. The primary outcome was the change from baseline in the visual analog scale (VAS) pain (0-10 cm) at 6 months. Secondary outcomes included the Ankle Osteoarthritis Scale (AOS) score, American Orthopedic Foot and Ankle Society (AOFAS) hindfoot-ankle score, single-leg stance test (SLS), rescue analgesics consumption and patient satisfaction. Thirty-nine participants (88.64%) completed the study. Significantly improvement in the VAS and AOS was noted at 1-, 3-, and 6-month follow-ups (p < .001). The mean VAS pain decreased significantly from 4.1 ± 1.7 at baseline to 2.2 ± 1.9, 1.7 ± 1.5, and 1.8 ± 1.6 at 1, 3, and 6 months (p < .001). The mean total AOS score reduced by 1.5, 2.2, and 2.1 from baseline respectively postinjection (p < .001). The mean AOFAS hindfoot-ankle score improved from 80.3 points at baseline to 87.2, 91.6, and 89.7 points at 1, 3, and 6 months (p < .001). SLS tests improved significantly (p < .001) at each follow-up. Acetaminophen consumption dropped significantly (p < .001) and no serious adverse events occurred. The study showed promise for a single intraarticular injection of PRP in the treatment of ankle OA.

Exosomes Derived from Non-Classic Sources for Treatment of Post-Traumatic Osteoarthritis and Cartilage Injury of the Knee: In Vivo Review

Osteoarthritis of the knee is one of the most common chronic, debilitating musculoskeletal conditions. Current conservative treatment modalities such as weight loss, non-steroidal anti-inflammatory drugs, and intra-articular steroid injections often only provide temporary pain relief and are unsatisfactory for long-term management. Though end stage osteoarthritis of the knee can be managed with total knee arthroplasty (TKA), finding alternative non-surgical options to delay or prevent the need for TKA are needed due to the increased healthcare costs and expenditures associated with TKA. Exosomes have been of particular interest given recent findings highlighting that stem cells may at least partially mediate some of their effects through the release of extracellular vesicles, such as exosomes. As such, better understanding the biological mechanisms and potential therapeutic effects of these exosomes is necessary. Here, we review in vivo studies that highlight the potential clinical use of exosomes derived from non-classical sources (not bone marrow or adipose derived MSCs derived MSCs) for osteoarthritis of the knee.

Effectiveness of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Meta-analysis of Randomized Controlled Clinical Trials

Background:

The effectiveness of platelet-rich plasma (PRP) injections for knee osteoarthritis and the effects of leukocyte-poor PRP (LP-PRP) versus leukocyte-rich PRP (LR-PRP) are still controversial.

Purpose:

To assess the effectiveness of different PRP injections through a direct and indirect meta-analysis of randomized controlled trials.

Study Design:

Systematic review; Level of evidence, 1.

Methods:

A systematic literature search of electronic databases (PubMed, Cochrane Library, and EMBASE) was performed to locate randomized controlled trials published through March 2019 that compared PRP with control treatment. A random-effects meta-analysis was conducted to synthesize the evidence, and meta-regression analyses were conducted to determine the influence of trial characteristics. An indirect comparison was performed to assess the effects of LP-PRP and LR-PRP compared with hyaluronic acid (HA).

Results:

A total of 21 trials were included. A clinically important benefit for pain relief was seen for intra-articular PRP compared with intra-articular saline (standardized mean difference [SMD] = –1.38 [95% CI, –2.07 to –0.70]; P < .0001; I² = 37%) and corticosteroid solution injection (SMD = –2.47 [95% CI, –3.34 to –1.61]; P < .00001; I² = 47%). As a result of heterogeneity (I² = 89%), there was no conclusive effect compared with HA, even though the pooling effect provided clinically relevant pain relief (SMD = –0.59 [95% CI, –0.97 to –0.21]; P = .003). Indirect meta-analysis showed that there was no significant difference between LR-PRP and LP-PRP.

Conclusion:

PRP injections are beneficial for pain relief and functional improvement in knee osteoarthritis. Larger, randomized high-quality studies are needed to compare the effects of LP-PRP and LR-PRP.

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/).

Intra-Articular Injections of Hyaluronic Acid or Steroids Associated With Better Outcomes Than Platelet-Rich Plasma, Adipose Mesenchymal Stromal Cells, or Placebo in Knee Osteoarthritis: A Network Meta-analysis

PURPOSE

To evaluate the clinical effects of hyaluronic acid (HA), steroids, platelet-rich plasma (PRP), or adipose mesenchymal stromal cell (MSC) injections in the treatment of knee osteoarthritis (OA).

METHODS

Randomized controlled trials with OA of the knee that compared HA, steroids, PRP, adipose MSC, or their combination with placebo or in head-to-head combination were identified from the MEDLINE, EMBASE, Cochrane Library, Web of Science, and SCOPUS databases up to June 30, 2019. We performed a network meta-analysis of the relevant literature to determine whether there was benefit from HA, steroids, PRP, or adipose MSC treatment as compared with placebo.

RESULTS

A total of 43 trials covering 5554 patients were included. Steroids were ranked most likely to be effective for the management of pain or function, with adipose MSC and multiple PRP appearing least likely to be effective. Although no significant difference was observed among the 6 interventions, except for single PRP with respect to adverse effects, steroids and HA exhibited a lower rate of AEs compared with the placebo. In view of severe adverse effects, only single PRP was superior to placebo. Direct pairwise meta-analysis for pain relief showed that HA was superior to placebo or single PRP, but steroids had a significantly worse effect than single PRP. In addition, direct pairwise meta-analysis for adverse effects favored steroids in comparison to HA.

CONCLUSIONS

The ranking statistics like surface under the cumulative ranking curve values of our network meta-analysis support the use of steroids and HA for appropriate patients with knee OA. For pain relief and AEs, steroids are most likely the best treatment, followed by HA. Single PRP, multiple PRP, and adipose MSC interventions do not result in a relevant reduction of joint pain nor improvement of joint function compared with placebo. However, treatment effect differences were small and potentially not clinically meaningful, indicating that other factors, such as cost and patient preferences, may be more important in patients with knee OA.

LEVEL OF EVIDENCE

meta-analysis of non-homogenous randomized controlled trials, Level II.

Intra-articular injections of platelet-rich plasma in symptomatic knee osteoarthritis: a consensus statement from French-speaking experts

PURPOSE

There has been much debate regarding the use of intra-articular injections of platelet-rich plasma (PRP) as symptomatic treatment for knee osteoarthritis. The objective of this consensus was to develop guidelines for PRP injections in knee osteoarthritis according to the French National Authority for Health recommendations.

METHODS

Fifteen physicians from different French-speaking countries (10 rheumatologists, 4 specialists in rehabilitation and sports medicine and 1 radiologist) were selected for their expertise in the areas of PRP and osteoarthritis. A comprehensive literature review was conducted on Medline including all published therapeutic trials, open studies, meta-analysis and systematic reviews focusing on the effects of PRP in knee OA, as well as fundamental studies concerning the characteristics of the various types of PRP and their mechanisms, indexed before April 2019. Using the method recommended by the French National Authority for Health inspired by the Delphi consensus process, 25 recommendations were finally retained and evaluated. The recommendations were classified as appropriate or not appropriate, with strong or relative agreement, or uncertain if a consensus was not achieved.

RESULTS

Among the 25 recommendations selected, the main ones are the following: (1) Intra-articular injections of PRP are an effective symptomatic treatment for early to moderate knee osteoarthritis. This recommendation was considered appropriate with a relative agreement (Median = 8; rank = 6-9). Level of evidence 1A. (2) A PRP treatment sequence in knee osteoarthritis may include 1-3 injections. This recommendation was considered appropriate with a strong agreement (Median = 9; rank = 7-9). Level of evidence 1A. (3) Leucocytes-poor PRP should be preferred in knee osteoarthritis. This recommendation was considered appropriate with a relative agreement (Median = 8; rank = 5-9). Level of evidence 5. (4) Intra-articular PRP knee injections should be performed under ultrasound or fluoroscopic guidance. This recommendation was considered uncertain with no consensus (Median = 8; rank = 3-9). Level of evidence 5. (5) PRP should not be mixed with an anesthetic or intra-articular corticosteroid. This recommendation was considered appropriate with a relative agreement (Median = 9; rank = 6-9). Level of evidence 5 CONCLUSION: Those 25 recommendations should standardize and facilitate the use of IA PRP injections, which are considered by experts as an effective treatment especially in early or moderate knee OA. Although a strong or relative agreement from the experts was obtained for most of the recommendations, many of them had a very low level of evidence (Level 5) and were principally based on the clinical experience of the experts.

The application of thermal oscillation method to augment the effectiveness of autologous platelet rich plasma in treating elderly patients with knee osteoarthritis

Elderly patients with knee osteoarthritis (OA) are often troubled with joint soreness, swelling, weakness, and pain. Knee intra-articular (IA) injection of autologous platelet rich plasma (PRP) is one of the options that can be used in treating knee OA. However, there are doubts on the effect of PRP when used in treating elderly patients with moderate to severe degrees of knee OA. In this study, 47 elderly patients with moderate degree of knee OA combined with supra-patellar bursitis were recruited. Musculoskeletal ultrasound was used for accurate needle placement for the aspiration of bursa synovial fluid SF followed by PRP injections. In group 1, 23 patients received conventional liquid-form IA PRP injections. In group 2, 24 patients received IA injections of thermal oscillation prepared PRP injectants. It was discovered that when the liquid-form PRP was heated up to a temperature of 75 °C and simultaneously oscillated under 200 revolutions per minute (rpm) for 15 min, the end product became paste-form like and with a viscosity similar to that of an anti-cough syrup. Under incubation, the highest number of platelet-derived growth factor (PDGF) was obtained on the 8th day. At one month after the completion of PRP injections, group 2 patients revealed significant decreases in SF total protein concentrations, SF volumes, and Lequesne index values. Proteins associated with inflammation, such as apolipoprotein A-I, haptoglobin, immunoglobulin kappa chain, transferrin, and matrix metalloproteinase also decreased significantly. Therefore, the thermal oscillation preparation method can augment the effectiveness of autologous PRP in treating elderly patients with moderate knee OA. It may be recommended that the PRP injectant should be prepared first using the thermal oscillation method to increase its viscosity, enabling prolonged release of growth factors once it is injected into the knee joint.

Platelet-rich plasma for the treatment of knee osteoarthritis: an expert opinion and proposal for a novel classification and coding system

INTRODUCTION

Platelet-rich plasma (PRP) is able to modulate the joint environment by reducing the inflammatory distress and promoting tissue anabolism. Therefore, it has gained increasing popularity among clinicians in the treatment of osteoarthritis (OA), and it is currently proposed beside consolidated options such as viscosupplementation.

AREAS COVERED

A systematic review of all available meta-analyses evaluating intra-articular PRP injections in patients affected by knee OA was performed, to understand how this biologic treatment approach compares to the traditional injective therapies available in clinical practice. Moreover, a novel coding system and 'minimum reporting requirements' are proposed to improve future research in this field and promote a better understanding of the mechanisms of action and indications.

EXPERT OPINION

The main limitation in the current literature is the extreme variability of PRP products used, with often paucity or even lack of data on the biologic features of PRP, which should not be considered as a simple substance, but rather a 'procedure' requiring accurate reporting of the characteristics of the product but also all preparation and application modalities. This approach will aid in matching the optimal PRP product to specific patient factors, leading to improved outcomes and the elucidation of the cost-effectiveness of this treatment.

Can the addition of ultrasound-guided genicular nerve block using 5% dextrose water augment the effect of autologous platelet rich plasma in treating elderly patients with knee osteoarthritis?

Background

To investigate whether the addition of injecting 5% dextrose water to the genicular nerves can augment the effect of platelet rich plasma (PRP) injections in treating elderly patients with moderate degree of knee osteoarthritis (OA).

Methods

Forty-six elderly patients with grade 3 on the Kellgren and Lawrence knee OA grading system were divided into control and genicular nerve block groups. Both groups received 4 milliliters (mL) of PRP injected into the knee joint and 2 mL of PRP to the pes anserinus complex. In the nerve block group, 2 mL of 5% dextrose water was also injected to each genicular nerve. In the control group, normal saline was used to inject the genicular nerves. Proteomic technique of 2-dimensional electrophoresis was used to detect the changes in synovial fluid (SF) protein concentrations. Lequesne Functional Index was used to evaluate knee functional status.

Results

After 3 monthly PRP injections, concentrations of SF total protein, and proteins associated with inflammation decreased. Protein concentrations associated with chelation increased. In the nerve block group, improvements in pain and in the functional status of the knee joint lasted up to a period of 6 months. At 1 month and 3 months after the injections, Lequesne Functional Index was less than 7 (a value of 7 or higher indicates knee OA).

Conclusion

The concept of combining 5% dextrose water injection to the genicular nerves, and PRP injection into the knee joint and to the pes anserinus complex can be a feasible non-operative conservative treatment option for elderly patients with knee OA.

Nanomechanical Properties of Articular Cartilage Due to the PRP Injection in Experimental Osteoarthritis in Rabbits

The purpose of this study was twofold. Firstly, we proposed a measurement protocol for the atomic force microscopy (AFM) method to determine the nanomechanical properties of articular cartilage in experimental osteoarthritis in rabbits. Then, we verified if mechanical properties can be evaluated with AFM shortly after platelet-rich plasma (PRP) injection. We hypothesized that the modulus determined by AFM indentation experiments could be utilized as a progressive disease marker during the treatment of osteoarthritis. The rabbits were equally divided into three groups of six: control (group 1); injections of saline (0.5 mL) and 10% surgical talc (Talcum Pharmaceutical^®, Minsk, Belarus) were delivered into the right knee under the patella (group 2 and 3); and PRP was injected into the right knee (group 3). In group 2, the arithmetic average of absolute values (Ra) change was a 25% increase; the maximum peak height (Rp) increased by over 102%, while the mean spacing between local peaks (S) increased by 28% (p < 0.05). In group 3, Ra increased by 14% and Rp increased by 32%, while S decreased by 75% (p < 0.05). The Young’s modulus of the surface layers decreased by 18% as a result of induced model of osteoarthritis (IMO) (p < 0.05), and it increased by 9% (p < 0.05) as a result of PRP therapy, which means that the mechanical properties of cartilage were partially recovered. This research demonstrates that Young’s modulus utilized on a nanometer scale has potential to be a progressive disease marker during the treatment of osteoarthritis.

Development and Prospect of Intra-Articular Injection in the Treatment of Osteoarthritis: A Review

Osteoarthritis (OA) is a common degenerative disease that affects the vast majority of the elderly and may eventually embark on the road of the total knee arthroplasty (TKA), although controversy still exists in the medical community about the best therapies for osteoarthritis. Compared with physical therapy, oral analgesics and other non-operative treatments, intra-articular injection is more safe and effective. Moreover, intra-articular injection is much less invasive and has fewer adverse reactions than surgical treatment. This article reviews mechanism, benefits and adverse reactions of corticosteroids (CS), hyaluronic acid (HA), platelet-rich plasma (PRP), mesenchymal stem cell (MSCs), stromal vascular fraction (SVF) and other new therapies (for example: gene therapy). The application prospect of intra-articular injection was analyzed according to the recent progress in drug research.

Intra-articular Injection of Pure Platelet-Rich Plasma Is the Most Effective Treatment for Joint Pain by Modulating Synovial Inflammation and Calcitonin Gene-Related Peptide Expression in a Rat Arthritis Model

BACKGROUND

Platelet-rich plasma (PRP) has emerged as a treatment for osteoarthritis (OA). However, the effect that leukocyte concentrations in PRP have on OA remains unclear.

PURPOSE

To clarify the optimal PRP formulation for OA treatment by comparing pure PRP, leukocyte-poor PRP (LP-PRP), and leukocyte-rich PRP (LR-PRP) in a rat arthritis model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Knee arthritis was induced bilaterally in male Wistar rats with intra-articular injections of monosodium iodoacetate (MIA) on day 0. Rats were randomly assigned to 1 of 3 treatment groups (pure PRP, LP-PRP, and LR-PRP). On day 1, allogenic PRP was injected into the right knee of rats and phosphate-buffered saline was injected into the left knee as a control. Weight distribution on the hindlimbs was measured for 14 days to assess pain behavior. Rats were euthanized at day 5 or 14 for histological assessment of synovial tissue and cartilage. Immunohistochemical staining of calcitonin gene-related peptide (CGRP) and α-smooth muscle actin was performed to determine the mechanism of pain relief induced by the PRP preparations.

RESULTS

In all groups, PRP increased the load-sharing ratio on PRP-injected knees, with pure PRP eliciting the largest effect among the 3 kinds of PRP (P < .05). Structural changes in the synovial tissue were significantly inhibited in the pure-PRP group compared with the control group after both 5 and 14 days (P < .001 and P = .025, respectively), whereas no significant difference was found between the control, LP-PRP, and LR-PRP groups. An inhibitory effect on cartilage degeneration was observed only in the pure-PRP group on day 14. Pure PRP also significantly inhibited expression of CGRP-positive nerve fibers in the infrapatellar fat pad compared with the other groups (P < .05).

CONCLUSION

In an MIA-induced arthritis model, pure PRP injection was the most effective treatment for reduction of pain-related behavior and inhibition of synovial inflammation and pain sensitization.

CLINICAL RELEVANCE

PRP formulations should be optimized for each specific disease. This study shows the superiority of pure PRP for treatment of arthritis and joint pain.

The effects of platelet-rich plasma injection in knee and hip osteoarthritis: a meta-analysis of randomized controlled trials

OBJECTIVE

We conducted this updated meta-analysis to evaluate the effects of PRP in patients with knee or hip OA.

METHOD

PubMed, Embase, and Web of Science were searched to identify randomized controlled trials (RCTs) that compared the efficacy of PRP with other intra-articular injections. The outcomes of interest included Western Ontario and McMaster (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), Visual Analog Scale (VAS), Harris Hip Score (HHS), and International Knee Documentation Committee (IKDC).

RESULTS

Twenty-four RCTs with 21 at knee OA and three at hip OA were included in this meta-analysis. The PRP injections significantly improved the WOMAC score, VAS score, IKDC score, and HHS score as compared with comparators. The WOMAC pain, stiffness, and physical function scores were also significantly better in the PRP group than in the control group. Most of the evaluated parameters that favored PRP were observed in knee OA but not in hip OA, at short-term (at 1, 2, 3, 6, 12 months) but not long-term follow-up (at 18 months), in RCTs with low risk of bias.

CONCLUSIONS

Intra-articular PRP injection provided better effects than other injections for OA patients, especially in knee OA patients, in terms of pain reduction and function improvement at short-term follow-up. Key Points • This updated meta-analysis, based on great sample size and high-quality studies, evaluates the effects of PRP in patients with knee or hip OA. • Intra-articular PRP injection provided better effects than other injections for OA patients. • Most of the evaluated parameters that favored PRP were observed in knee OA at short term (at 1, 2, 3, 6, 12 months).

Should Platelet-Rich Plasma or Stem Cell Therapy Be Used to Treat Osteoarthritis?

Osteoarthritis is the most common form of arthritis and unfortunately lacks disease-modifying treatments. This has led to a growing demand for more effective nonoperative treatment options. Platelet-rich plasma and mesenchymal stem cell therapy offer the potential to modify the natural course of knee osteoarthritis using cell-based technology. Because of the lack of high-quality evidence and the large degree of heterogeneity, in terms of study designs and measured outcomes, the use of platelet-rich plasma or mesenchymal stem cell therapy to treat knee osteoarthritis cannot be recommended at this time.

Role of platelet-rich plasma in early osteoarthritis of knee joint: Experience from a tertiary care center in Pakistan

PURPOSE

Osteoarthritis is the most common articular disease. The aim of this study was to observe the outcome after intra-articular platelet-rich plasma (PRP) injection in our patients presenting with knee osteoarthritis.

METHODS

This study was conducted in Dow University of Health Sciences, Karachi, Pakistan, from December 2014 to December 2015. All patients between 35 years and 60 years of age diagnosed with grade I and II arthritis were included in the study. Three PRP injections were injected in the knees at 4-week interval. Patients were followed up in outpatient department (OPD) and were assessed for pain and physical activity associated with arthritis using the Western Ontario and McMaster University Arthritis Index (WOMAC) score at the time of induction in the study and at 6 months interval.

RESULTS

Two hundred fourteen patients with the mean age of 55.15 (±6.93) years were studied. Female to male ratio was 3:1. One hundred fifty-five patients were classified as having Kellgren-Lawrence grade 1 osteoarthritis, while 59 were grade 2. One hundred eighty-nine patients had clinical symptoms for less than 2 years and 25 for more than 2 years. Mean WOMAC score before the start of treatment was 83.05, and after 6 months, it was reduced to 38.84 which was statistically significant ( p = 0.000). WOMAC score was improved more in the subgroup with patients having symptoms less than 2 years ( p = 0.005). Three patients developed minor hyperemia which was managed conservatively with activity limitation and ice application, but none of the patient developed gross infection.

CONCLUSION

The sequential use of PRP injection for the treatment of early osteoarthritis proved to be effective in our study.

Platelet Rich Plasma for Treatment of Rheumatoid Arthritis: Case Series and Review of Literature

Platelet-rich plasma (PRP) is an autologous blood product with platelets above circulating levels and releases several growth factors after activation. PRP may help to decrease joint inflammation by modulating synovial cell proliferation and differentiation and inhibition of catabolic pathways in various articular conditions. Though PRP has shown good efficacy in osteoarthritis and other musculoskeletal conditions such as synovitis, epicondylitis, skeletal muscle injuries, and tendinopathy, there is limited experience for the use of PRP in patients with rheumatoid arthritis. Precise mechanisms of action of PRP are not known. We present clinical experience for treatment with PRP (2–4 ml) in four patients with rheumatoid arthritis who had inadequate response and persistent pain and inflammation with intra-articular steroids. Irrespective of past and ongoing treatments and duration of disease, all patients showed improvement in the visual analog scale and disease activity score of 28 joints at 4 and 8 weeks after injection. There was an improvement in joint inflammation on ultrasound imaging in some patients. These effects were sustained for up to 1 year. No adverse effects were reported in any patient. PRP may be a safe and useful therapy in patients with rheumatoid arthritis who fail to respond to one or more established treatment options.

MRI Changes After Platelet Rich Plasma Injection in Knee Osteoarthritis (Randomized Clinical Trial)

Purpose

Few papers have studied the objective effects of PRP on cartilage. In this study, we investigated the effect of PRP on cartilage characteristics by special MRI sequencing in knee osteoarthritis (IRCT registration number: 2014020413442N6).

Patients and methods

In this double blind randomized clinical trial, patients with bilateral knees osteoarthritis-grade 1, 2, and 3 were included in the study. Each patient's knees were randomly allocated to either control or treatment groups. PRP was injected in two sessions with 4 week intervals in PRP group. The VAS (visual analog scale) and WOMAC (Western Ontario and McMaster Universities Arthritis Index) were utilized and MRI was performed for all patients, before, and 8 months after treatment. The MRI sequences taken were transverse 3D TRUFISP and coronal and sagittal fat saturated proton-density. Imaging was scored according to four cartilage characteristics.

Results

46 knees (from 23 patients) were included in this study. 23 knees in the case group and 23 knees in control group were studied. All patients were female with mean age of 57.57±5.9 years. Mean total WOMAC and VAS changes before and after treatment in control group were 11.61±8.5 and 1.3±1.1 respectively. In PRP group, mean total WOMAC and VAS changes showed better improvement with 20±12.3 and 3.2±1.6 respectively (P-value <0.05). In PRP group, all of the radiologic variables (patellofemoral cartilage volume, synovitis and medial and lateral meniscal disintegrity), with the exception of subarticular bone marrow abnormality, had significant improvement (P-value <0.05). In a comparison between the two groups, patellofemoral cartilage volume and synovitis had significantly changed in the PRP group (P-value <0.05).

Conclusion

In this study, in addition to the effect of PRP on VAS and WOMAC, there was a significant effect on radiologic characteristics (patellofemoral cartilage volume and synovitis). For further evaluation, a longer study with a larger sample size is recommended.

Comparison of the Clinical Effectiveness of Single Versus Multiple Injections of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review and Meta-analysis

Background

Reports have concluded that platelet-rich plasma (PRP) is an effective and safe biological approach in the treatment of knee osteoarthritis (OA). However, no consensus has been established regarding the number of injections required to observe a therapeutic effect.

Purpose

To compare the clinical effectiveness reported in randomized controlled trials (RCTs) of single versus multiple PRP injections in the treatment of knee OA.

Study Design

Systematic review; Level of evidence, 1.

Methods

A comprehensive search was conducted for RCTs published between 1970 and 2019 that compared the effect of single versus multiple PRP injections on pain and functionality in patients with knee OA. Searched databases included MEDLINE, Scopus, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. A data extraction form was designed to obtain bibliographic information of the study as well as patient, intervention, comparison, and outcomes of interest data. A random-effects model was used to pool quantitative data from the primary outcomes.

Results

We included 5 clinical trials with a low-moderate risk of bias that reported data for 301 patients. Meta-analysis showed that, at 6 months after the intervention, single and multiple (double or triple) injections had similar pain improvement, with no significant differences (standardized mean difference [SMD], 0.61 [95% CI, -1.09 to 2.31]; I ² = 97%; P = .48). A significant improvement in knee functionality was observed in favor of multiple injections (SMD, 2.29 [95% CI, 0.45-4.12]; I ² = 97%; P = .01). Subanalysis showed that the significant improvement was only evident for the results of single versus triple injections (SMD, 3.12 [95% CI, 0.64-5.60]; I ² = 97%; P = .01).

Conclusion

According to our results, a single injection was as effective as multiple PRP injections in pain improvement; however, multiple injections seemed more effective in joint functionality than a single injection at 6 months. We consider that the available evidence is still insufficient, and future research on this specific topic is needed to confirm our results.

Can intra-articular injection of freeze-dried platelet-derived factor concentrate regenerate articular cartilage in the knee joint?

Freeze-drying methods not only enable the delivery of growth factors using platelets, but also extend the shelf-life of platelet concentrates. The present study shows the clinical results of treating knee osteoarthritis with freeze-dried platelet-derived factor concentrate (PFC). While it improved pain, activities of daily living, sports and recreational activities, and knee-related quality of life, it did not significantly improve symptoms other than pain, such as restricted range of motion and mechanical symptoms. As such, the treatment effect may be attributed to anti-inflammatory action rather than actual cartilage regeneration.

The influence of sample size and gender composition on the meta-analysis conclusion of platelet-rich plasma treatment for osteoarthritis

Objective

The magnitude of the therapeutic effects of intra-articular injection of platelet-rich plasma (PRP) on osteoarthritis (OA) is still under debate. The goal of this study that was a systematic review of randomised controlled trials ​of PRP injections for the treatment of OA was to elucidate the therapeutic efficacy of PRP.

Methods

Electronic databases of PubMed, CENTRAL, EMBASE, EBSCO, ClinicalTrials.gov, and International Clinical Trials Registry Platform ​were searched from inception to June 2018 for RCTs that compared PRP injections to controls in patients with OA. A random-effects approach was used to compile data and subgroups according to trial size (large trials versus small trials), patient profile (age and gender), and PRP preparation method was performed.

Results

Thirty trials met the inclusion criteria and were analysed. All results had unexplained statistical heterogeneity. Patients treated with PRP compared with control showed statistically relevant pain relief and function improvement at short term (standardised mean difference [SMD] ​= ​−0.62, 95% confidence interval [CI]: −0.98 to −0.27, P ​= ​0.0006, SMD ​= ​−0.74, 95% CI: −1.11 to 0.36, P ​= ​0.0001, respectively), medium term (SMD ​= ​−0.53, 95% CI: −0.83 to −0.23, P ​= ​0.0006, SMD ​= ​−0.50, 95% CI: −0.75 to −0.25, P ​= ​0.0006), and long term (SMD ​= ​−0.69, 95% CI: −1.08 to −0.30, P ​= ​0.0006, SMD ​= ​−0.68, 95% CI: −0.1.09 to −0.27, P ​= ​0.001, respectively). A subgroup analysis of the data from large trials and from trials composed of less than 50% female patients revealed that therapeutic effects of the treatment are insignificant.

Conclusions

According to the currently available data, PRP injections are beneficial for pain relief and function improvement in patients with OA. This meta-analysis, however, demonstrated that the efficacy of PRP is related to sample size and gender composition. Thus, more randomised controlled trials of high quality and larger patient size, also including gender aspects, are required to understand this phenomenon.

The translational potential of this article

The translation potential of this meta-analysis is that provided another perspective to analyse the treatment effect of PRP for OA. In future research, phenotypes subpopulation and gender difference of OA patient should be considered for PRP treatment.

Efficacy of platelet-rich plasma for non-transfusion use: Overview of systematic reviews

INTRODUCTION

Platelet-rich plasma (PRP) is a blood component therapy with a supraphysiological concentration of platelets derived from allogenic or, more commonly, autologous blood. PRP has been used in different non-transfusion indications because of its role in the promotion of tissue repair and healing, in fields such as Traumatology, Dermatology and Dentistry.

OBJECTIVE

To provide a synthesis of the efficacy of PRP for different clinical situations.

METHODS

Systematic searches were carried out in MEDLINE, Embase, Cochrane Library and LILACS in July 2018 to identify systematic reviews (SRs) of randomized clinical trials (RCTs) focusing on PRP for non-transfusion use. Two authors independently screened all retrieved references in two stages (titles and abstracts at a first stage and full texts at a second stage). The methodological quality of SRs that met the eligibility criteria was appraised by AMSTAR 2. Conclusions were based on the most recent SRs with highest quality.

RESULTS

One thousand two hundred and forty references were retrieved. After checking the inclusion criteria, 29 SRs of RCTs related to three different fields (wound care, Orthopedics and Dentistry) were included. The results suggest the benefit of PRP for different clinical situations, such as diabetic wounds, acute lesions of musculoskeletal system, rotator cuff lesions, tendinopathies, knee and hip osteoarthritis, total knee arthroplasty, allogenic bone graft for dental implants and periodontal intrabony defects.

CONCLUSION

There is low to moderate quality evidence supporting the efficacy of PRP for specific clinical situations. The low quality of the evidence limits the certainty of these findings. Well-planned and well-conducted RCTs are still needed to further assess the efficacy of PRP.