Clinical and radiographic comparison of a single LP-PRP injection, a single hyaluronic acid injection and daily NSAID administration with a 52-week follow-up: a randomized controlled trial

Efficacy of intra-articular injections for the treatment of osteoarthritis: A narrative review

Osteoarthritis (OA) is a prevalent degenerative joint disease characterized by progressive cartilage loss, inflammation, and joint dysfunction. With profound effects on joint function and quality of life, OA imposes a substantial socio-economic burden. As of now, OA remains incurable, lacking approved medications, regenerative therapies, or procedures that can halt the progressive destruction of the joint. Intraarticular (IA) injections have emerged as a cornerstone in the management of knee OA, offering localized minimally invasive therapeutic options. Traditional IA therapies, including corticosteroids and hyaluronic acid (HA), primarily aim to reduce pain but lack regenerative capacity. Biologic IA therapies for knee OA including autologous blood-derived products like platelet-rich plasma (PRP), bone marrow aspirate concentrate (BMAC) and mesenchymal stromal cells (MSCs) have become more commonly used. Finally, newer IA therapies such as fibroblast growth factor 18 and gene therapy are being investigated. In this review, we highlight the current evidence around IA injections for the treatment of knee OA.

3D-MRI analysis of cartilage thickness changes after PRP injection in medial knee osteoarthritis: A preliminary report

The regenerative effect of platelet-rich plasma injection on cartilage in knee osteoarthritis remains controversial. The purpose of this study was to use our recently developed 3D-MRI evaluation system to examine in detail the changes in cartilage thickness occurring six months after platelet-rich plasma injection. This study included 21 knees from 16 patients with medial knee osteoarthritis. An autologous protein solution (APS) was injected as platelet-rich plasma, and magnetic resonance imaging scans were taken before and six months after the injection. Cartilage thickness was quantified in seven regions using SYNAPSE 3D. Based on previous studies, the measurement error was set at 0.1 mm. The proportion of knees in which cartilage thickness increased (>0.1 mm) was highest in the anteromedial femoral region (43%); followed by the anterolateral femoral and lateral tibial regions (24%); the posterolateral femoral, patellar, and medial tibial regions (19%); and lowest in the posteromedial femoral region (14%). Notably, in the posteromedial femoral and medial tibial regions, which are primarily affected by medial osteoarthritis, less than 20% of the knees showed increased cartilage thickness. Our findings suggest that while platelet-rich plasma injection may have a positive effect on cartilage thickness in certain regions of the knee, its impact on the regions most affected by medial osteoarthritis appears limited.

Comparative analysis of single-dose platelet-rich plasma and hyaluronic acid therapies in knee osteoarthritis: A 12-week follow-up study

OBJECTIVE

Osteoarthritis (OA) is a prevalent and disabling joint condition that affects millions worldwide, particularly in the knee joint, and it presents limited therapeutic options. Platelet-rich plasma (PRP) and hyaluronic acid (HA) have emerged as promising intra-articular treatments. This study aimed to compare the effects of single-dose PRP and HA on pain, functionality, and stiffness in patients with knee OA over a 12-week follow-up period.

METHODS

A retrospective analysis was conducted on 64 patients who underwent single-dose intra-articular HA or PRP treatment for knee OA between December 2021 and June 2022. Pain and functional outcomes were assessed using the Visual Analogue Scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. Patient satisfaction was evaluated using a Likert scale. Appropriate statistical analyses were performed to compare treatment outcomes and p<0.05 was considered statistically significant.

RESULTS

Both PRP and HA treatments led to significant improvements in pain, functionality, and stiffness over the 12-week follow-up period. VAS pain scores decreased significantly in both groups, but a greater reduction was observed in the HA group. Additionally, the HA group exhibited superior improvement in the WOMAC physical function score at the 4-week mark (p=0.047).

CONCLUSION

This study is another novel contribution to the growing literature on treatment of PRP and HA treatments for knee OA, where we highlighted the potential benefits of single-dose HA in alleviating pain and enhancing physical function.

Efficacy of multiple autologous apheresis platelet-rich plasma injections for treating knee osteoarthritis and its influencing factors: a retrospective cohort study

BACKGROUND

The lack of standardized Platelet-Rich Plasma (PRP) protocols for Knee Osteoarthritis (KOA), combined with significant patient variability, leads to inconsistent PRP effectiveness across studies. This study aims to assess the influence of PRP injection frequencies on KOA treatment and explore the role of patient characteristics and PRP properties in the treatment's effectiveness.

METHODS

A retrospective cohort study was conducted with KOA patients who received three PRP injections (4-week intervals) at a hospital in Chongqing. The Wilcoxon signed-rank test was used to analyze differences in self-reported recovery rates across different treatment time points, with Bonferroni correction applied for significance level adjustment (α). The Mann-Whitney U test, Kruskal-Wallis H test, Spearman correlation analysis, and restricted cubic spline models were used to assess the associations between sex, baseline Kellgren-Lawrence grade, age, PRP red blood cell (RBC) concentration, PRP white blood cell (WBC) concentration, PRP platelet concentration, the multiple of PRP platelet concentration relative to the baseline autologous level (Enrichment-PLT), and self-reported recovery rates.

RESULTS

The study included 28 KOA patients. Significant improvement in self-reported recovery rate was observed 4 weeks after the first treatment (median: 30.0%, P < 0.008) and after the second treatment (median: 45.0%, P < 0.008). However, no significant change was noted 4 weeks after the third treatment (median: 55.0%, P = 0.058), and recovery rates at 8, 12, and 24 weeks post-third treatment showed no significant differences compared to 4 weeks (all P > 0.008). Additionally, no correlations were found between sex, baseline Kellgren-Lawrence grade, age, PRP RBC concentration, PRP WBC concentration, PRP platelet concentration, or Enrichment-PLT and self-reported recovery rates.

CONCLUSION

At least two PRP injections are recommended, with effects lasting for at least 24 weeks. Factors such as sex, age, baseline Kellgren-Lawrence grade, and PRP properties (prepared by apheresis) do not significantly affect treatment outcomes.

Systematic Review of Randomized Controlled Trials Evaluating the Use of Platelet-Rich Plasma for Knee Osteoarthritis: Adherence to Minimum Information for Studies Evaluating Biologics in Orthopaedics

BACKGROUND

The Minimum Information for Studies Evaluating Biologics in Orthopedics (MIBO) guidelines were developed in May 2017 to encourage improved reporting standards, promote increased transparency and reproducibility, and enhance clinical evaluation capabilities. The MIBO guidelines consist of 23 checklist items considered necessary to critically appraise clinical studies evaluating platelet-rich plasma (PRP).

PURPOSE

To assess randomized controlled trials that evaluated PRP for the treatment of knee osteoarthritis in order to systematically review their adherence to the MIBO guidelines.

STUDY DESIGN

Systematic review. Level 1a.

METHODS

A search was performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The inclusion criteria were randomized controlled trials reporting on knee osteoarthritis treated with intra-articular PRP. The studies were categorized into pre-, peri-, and post-MIBO groups based on the start date of data collection. The overall MIBO scores, defined as percentage of checklist items out of the 23 checklist items reported in 1 study, individual item scores, defined as percentage of studies reporting the checklist item within a specified group, and overall item score defined as the average of the individual item scores from all the included studies were calculated.

RESULTS

The review included 87 studies (7925 patients; 8118 knees). Of these, 51 studies were assigned to the pre-MIBO group, 19 studies to the peri-MIBO group, and 17 studies to the post-MIBO group. The overall MIBO score was 72%. No statistically significant differences in MIBO scores were found among the 3 MIBO groups (P = .345). The majority of the studies (62 studies; 71%) had MIBO scores <80%. MIBO items with particularly low item scores included reporting of whole-blood characteristics (20%), platelet recovery rate (22%), PRP analysis (30%), and PRP activation (47%). No significant difference among the 3 MIBO groups was found for the item scores except for the reporting of the recipient details (P = .012).

CONCLUSION

This study highlights the deficiencies in adherence to the MIBO guidelines, particularly in reporting key variables such as whole-blood characteristics, platelet recovery rate, PRP analysis, and PRP activation. These findings suggest that the publication of the MIBO guidelines has not resulted in improved reporting practices in studies investigating intra-articular PRP for the treatment of knee osteoarthritis.

Intraarticular leukocyte-poor platelet-rich plasma injection is more effective than intraarticular hyaluronic acid injection in the treatment of knee osteoarthritis: a systematic review and meta-analysis of 12 randomized controlled trials

PURPOSE

We aim to compare the clinical effects of intraarticular leukocyte-poor platelet-rich plasma (LP-PRP) injection with those of intraarticular hyaluronic acid (HA) injection in adult patients with knee osteoarthritis.

METHODS

Two authors independently reviewed databases, including PubMed, Web of Science, and the Cochrane Library. Only randomized controlled trials (RCTs) were included in our meta-analysis. Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores (WOMAC total, pain, stiffness, and physical function scores), visual analog scale (VAS) scores, EQ-VAS scores, International Knee Documentation Committee (IKDC) scores, and adverse events were used as outcome measurements to evaluate the efficacy of LP-PRP and HA treatment.

RESULTS

After screening 377 potential articles, 12 RCTs were included in this systemic review and meta-analysis. The WOMAC total scores and WOMAC physical function scores of the LP-PRP group were better than those of the HA group at 6 and 12 months. VAS scores of the LP-PRP group were better than those of the HA group at 3, 6, and 12 months. The LP-PRP group showed a better outcome of IKDC scores than the HA group at 6 months. There was no significant difference in adverse events between the LP-PRP and HA groups.

CONCLUSION

Intraarticular injections of LP-PRP showed better overall outcomes, such as WOMAC total scores, WOMAC physical function scores, VAS scores, and IKDC scores, compared with HA for adult patients with knee osteoarthritis at 6- and 12-month follow-up periods. Also, LP-PRP showed better pain relief compared with HA at 3-, 6-, and 12-month follow-up periods. Intraarticular LP-PRP improves pain relief and overall outcomes in patients with knee osteoarthritis.

Comparison of hyaluronic acid and platelet-rich plasma in knee osteoarthritis: a systematic review

BACKGROUND

Knee osteoarthritis (KOA) is a common joint disorder, and intra-articular injections of hyaluronic acid (HA) or platelet-rich plasma (PRP) are frequently employed therapeutic interventions. However, there remains controversy regarding their efficacy. This systematic review aims to compare the effectiveness and safety of HA and PRP through a meta-analysis, with the objective of identifying the optimal treatment protocol for KOA and enhancing its management.

METHODS

Randomized controlled trials evaluating the clinical outcomes of patients receiving intra-articular injections of either HA or PRP were included as eligible studies. Two independent investigators assessed the selected studies and evaluated their risk of bias. Primary outcome measures included the Visual Analog Scale (VAS) score, the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and other relevant assessment indices. Dichotomous variables were analyzed using risk ratios (RR) with 95% confidence intervals (CI). Data analysis was conducted using RevMan software (version 5.3).

RESULTS

A total of forty-two randomized controlled trials were included in this meta-analysis. No significant differences were observed between the patient populations in the two groups. The analysis demonstrated that PRP resulted in lower VAS and WOMAC scores compared to HA. Additionally, PRP exhibited superior performance across other evaluation indices. Notably, the incidence of adverse events was higher in the PRP group; however, all reported complications were mild.

CONCLUSIONS

Based on the current evidence, intra-articular injection of PRP appears to be more effective than HA for the treatment of KOA, as indicated by the analysis of VAS, WOMAC scores, and other evaluation indices.

TRIAL REGISTRATION

Retrospectively registered.

Long-term effectiveness of intra-articular injectables in patients with knee osteoarthritis: a systematic review and Bayesian network meta-analysis

BACKGROUND

Intra-articular injectables are proposed as a solution for pain relief and functional improvement in knee osteoarthritis (OA), however most studies involving intra-articular knee injectables are focused on short-term relief, leaving the recommendations regarding long-term management unclear. This network meta-analysis aimed to evaluate the mid- to long-term effectiveness of intra-articular knee injection of platelet-rich plasma (PRP), hyaluronic acid (HA), corticosteroids (CS), and their combinations for management of knee OA.

METHODS

Relevant studies were searched through PubMed, EMBASE, Scopus, and Cochrane Register of Trials databases from inception to 20th October, 2024 for randomized controlled trials (RCTs) of knee OA patients who had taken intra-articular injectable treatment with a follow-up duration of at least one year. The study included 37 RCTs involving 5089 patients. The outcomes assessed were pain relief and functional improvement of knee joint. The random effects Bayesian model was carried out for network meta-analysis. The surface under the cumulative ranking (SUCRA) curve demonstrated the rank probability of each injectable therapy for different outcomes.

RESULTS

Analysis revealed that, in terms of both knee pain relief and improvement of functional outcomes, the combined intra-articular injection of PRP and HA was ranked ahead of the isolated administration of PRP, followed by combination of HA with CS, HA alone, placebo, and CS at the end of one year.

CONCLUSION

These findings emphasize the sustained efficacy of PRP, particularly when combined with HA, in providing superior long-term pain relief and functional improvement in knee OA compared to other intra-articular injectables, highlighting its potential as a preferred treatment modality.

Intra-articular injections of hyaluronic acid versus plasma rich in growth factors (PRGF) for knee osteoarthritis: a meta-analysis of randomised controlled trials : A meta-analysis

INTRODUCTION

The present meta-analysis compared intra-articular injections of hyaluronic acid (HA) versus plasma rich in growth factors (PRGF) in patients with knee osteoarthritis (OA). The outcome of interest was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).

METHODS

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses: the 2020 PRISMA statement. All the head-to-head randomised controlled trials (RCT) comparing intra-articular HA injections versus PRGF were accessed and included in the present study. Only studies that clearly stated that injections were performed in patients with knee OA, irrespective of the severity of OA, were considered. Data concerning the WOMAC index were retrieved at baseline and last follow-up. The endpoint of interest was to investigate whether intra-articular HA injections are associated with WOMAC score improvement compared to PRGF injections at 4-6 months follow-up.

RESULTS

Data from 432 patients were collected and 76.3% (330 of 432) of the patients were women. The mean age of the patients was 58.2 ± 1.5 years and the mean body mass index (BMI) was 28.0 ± 0.5 kg/m2. At baseline, comparability in mean age, BMI, male:female ratio, WOMAC and related subscales were documented. The PRGF group evidenced lower values of the function subscale of the WOMAC index (P = 0.03). No difference was found in the overall WOMAC index (P = 0.05) and its stiffness (P = 0.4) and pain (P = 0.07) subscales.

CONCLUSION

The current level I evidence suggests that the use of PRGF might be associated with more favorable clinical outcomes than using HA.

Effect of platelet-rich plasma versus placebo or corticosteroid for knee osteoarthritis: A systematic review and meta-analysis of randomized controlled trials

Background

The effectiveness of intra-articular platelet-rich plasma (IA-PRP) injections for managing pain in knee osteoarthritis (KOA) remains inconsistent. Therefore, this study aimed to systematically review randomized controlled trials (RCTs) assessing the efficacy of IA-PRP.

Methods

A total of 21 studies meeting the inclusion criteria were selected from various scientific databases, all of which compared PRP to either a placebo or an active comparator, such as corticosteroids (CS), in the treatment of KOA. Weighted mean differences (WMDs) for the Visual Analogue Scale (VAS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Knee Injury and Osteoarthritis Outcome Score (KOOS), along with their 95 % confidence intervals (CIs), were calculated for each study. A subgroup analysis was conducted for the pain scores, comparing leukocyte-poor and leukocyte-rich PRP with either a placebo or CS. The evidence was synthesized using a random-effects meta-analysis.

Results

There were 2406 participants in all included studies; 1223 were in the PRP versus placebo group and 1183 were in the PRP versus corticosteroid group. The IA-PRP showed significant improvement of VAS, and WOMAC scores compared to placebo (P < 0.00.05), except KOOS score (P > 0.05). All pain scores were highly sinficant improved with IA-PRP, compared to IA-CS (P < 0.05). Additionally, the leukocyte rich PRP was efficasious than leukocyte poor PRP (P < 0.05) improving the all pain scores at the 6-month follow-up.

Conclusions

PRP treatment showed better results than placebo and corticosteroids in terms of reducing pain and improving function in KOA patients. Furthermore, lecocyte rich PRP is more effective than lecocyte poor PRP [PROSPERO, CRD42024540507].

Most Orthopaedic Platelet-Rich Plasma Investigations Don't Report Protocols and Composition: An Updated Systematic Review

PURPOSE

To systematically review the literature to assess the heterogeneity of platelet-rich plasma (PRP) preparation and composition reporting for the treatment of musculoskeletal/orthopaedic pathologies.

METHODS

A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to identify Level I and Level II studies from 2016 to 2022 that evaluated the use of PRP therapy for musculoskeletal pathologies. The search phrase used was "platelet-rich plasma clinical studies." Studies were assessed based on their reporting of the PRP preparation methods and reporting of PRP composition.

RESULTS

One hundred twenty-four studies (in 120 articles) met inclusion criteria for analysis. Of these studies, 15 (12.1%) provided comprehensive reporting, including a clear, well-described, and reproducible preparation protocol that future investigators can follow. Thirty-three studies (26.6%) quantitatively reported the final PRP product composition.

CONCLUSIONS

Among the studies using PRP for the treatment of musculoskeletal/orthopaedic pathologies, less than 20% provided a clear, well-described, and reproducible PRP preparation protocol, and only one-fourth of studies reported on the final PRP product composition.

CLINICAL RELEVANCE

A diverse current reporting of PRP composition between studies provides a high heterogeneity of the term "PRP," which becomes a limitation for a comparison of studies using PRP.

A Greater Platelet Dose May Yield Better Clinical Outcomes for Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review

PURPOSE

To determine whether the platelet dose administered during a platelet-rich plasma (PRP) injection for knee osteoarthritis (OA) affects clinical outcomes.

METHODS

A systematic review was performed by searching PubMed, Cochrane Library, and Embase for randomized controlled trials with at least 1 study arm using PRP for knee OA. Only studies that provided a platelet count, concentration, or dose with a minimum of 6-month outcome scores were included. Studies in which the PRP group had statistically significant positive outcomes were separated from those without statistical significance. The average platelet doses for studies with positive outcomes in the PRP group were compared with those without positive outcomes.

RESULTS

After exclusion criteria were applied, 29 studies were analyzed. Of the 29, there were 31 arms that used PRP as a treatment method, of which 28 had statistically significant positive outcomes at 6 months compared with the control group. The mean platelet dose in the 28 with a positive outcome was 5,500 ± 474 × 106, whereas the 3 that had no positive difference had a mean platelet dose of 2,302 ± 437 × 106 (P < .01). There were 18 studies with 12-month outcomes, with 16 of 18 having positive outcomes. The positive studies had an average platelet dose of 5,464 ± 511, whereas the studies that had no statistical difference had an average platelet dose of 2,253 ± 753 × 106 (P < .05).

CONCLUSIONS

Improved clinical outcomes from PRP injections for knee OA may be related to a greater platelet dose.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Comparison of Different Molecular Weights of Intra-Articular Hyaluronic Acid Injections for Knee Osteoarthritis: A Level I Bayesian Network Meta-Analysis

Background: The present Bayesian network meta-analysis compared the efficacy of intra-articular injections of different molecular weights of hyaluronic acid (HA) in patients with knee osteoarthritis. Methods: In November 2024, the following databases were accessed: PubMed, Web of Science, Google Scholar, and Embase. All randomised controlled trials investigating the efficacy of intra-articular HA injections for knee osteoarthritis were accessed. The outcome of interest was to evaluate pain according to the visual analogue scale (VAS). The groups included for comparison were the ultra-high molecular weight (UHMW), high molecular weight (HMW), medium molecular weight (MMW), and low molecular weight (LMW). Results: Data from 9822 patients were collected. The mean age of the patients was 62.1 ± 5.0 years with given comparability at baseline. Different follow-up periods were compared. The longest control period ranged from four to six months, and the UHMW and HMW injections were the interventions associated with the greatest reduction in the VAS. LMW HA was the intervention associated with the lowest decrease in VAS, falling short of the control group. Conclusions: The main findings of the present Bayesian network meta-analysis, with a current level I of evidence, suggests that the UHMW and HMW HA has a beneficial effect on pain at 6 months post intervention in patients with knee osteoarthritis.

Similar efficacy of intra-articular hyaluronic acid injections and other biologically active injections in patients with early stages knee osteoarthritis: a level I meta-analysis

INTRODUCTION

The present meta-analysis compared the efficacy of intra-articular hyaluronic acid (HA) injections in patients with early to mild knee osteoarthritis (OA) (Kellgren Lawrence I-II) versus other commonly injected biologically active compounds using patient-reported outcome measures (PROMs). The outcomes of interest were the visual analogue scale (VAS) and the Western Ontario McMaster Osteo-Arthritis Index (WOMAC) scores.

METHODS

This study was conducted according to the 2020 PRISMA statement. In April 2024, PubMed, Web of Science, Google Scholar, and Embase were accessed without time constraints. All the randomised controlled trials (RCTs) investigating the efficacy of intra-articular HA injections in the early stages of knee OA were accessed. Data concerning the VAS, WOMAC, and related subscales were collected at baseline and the last follow-up. Only studies clearly stated the degrees of advancement of OA using the Kellgren-Lawrence scoring system were used.

RESULTS

The literature search resulted in four RCTs (390 patients). The mean length of the last follow-up was 7.5 ± 3.0 months. 72.3% (282 of 390) of the patients were women. The mean age of the patients was 58.1 ± 3.2 years, and the mean BMI was 27.3 ± 3.2 kg/m2. At the last follow-up, no difference was found between HA and the control group in VAS, WOMAC, and related subscales.

CONCLUSION

In patients with early to mild knee osteoarthritis, the current level of evidence suggests that intra-articular injections using HA performed similarly to other biologically active compounds commonly injected in the knee joint for a minimum of three months.

LEVEL OF EVIDENCE

Level I, meta-analysis.

Optimal Dosage of Platelet-Rich Plasma Injections in Patients With Osteoarthritis of the Knee: A Scoping Review

Knee osteoarthritis (KOA) is a healthcare burden affecting over 595 million people worldwide. Recently, intra-articular platelet-rich plasma (PRP) injections from the patient's blood have shown promise in slowing KOA progression due to platelets' regenerative properties. This study aimed to evaluate the optimal dosing and schedule for PRP therapy in managing mild to moderate KOA. A systematic search was conducted across Embase, Ovid Medline, Web of Science, Cochrane Central, and CINAHL using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify articles published from August 2015 to March 2024. Keywords included "platelet rich plasma," "knee osteoarthritis," and "administration schedule." Inclusion criteria were studies on human patients utilizing PRP as monotherapy in experimental trials, while review articles, editorials, case reports, and meta-analyses were excluded. Three reviewers independently extracted and described patient interventions and outcomes, focusing on Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analog Scale (VAS), and imaging changes. Thirty-nine publications with PRP monotherapy protocols were found, with fourteen meeting the inclusion criteria. Twelve studies were randomized clinical trials, and two were longitudinal cohort studies, totaling 1704 patients with a mean follow-up of 7.51 ± 4.82 months. The most common PRP protocol was 4.357 ± 1.419 mL infusions, with three doses every four weeks and a single dose being frequent. Platelet values varied, with seven including a mean platelet count, three reporting that the platelet concentration in each dose had to be at least 150,000/μL, and four did not include platelet concentration. There was notable variation in PRP acquisition protocols, blood volume, and centrifugation processes across studies. Therapeutic benefits were represented by WOMAC and VAS scores rather than imaging changes. PRP injections appear to be safe and effective for symptomatic relief of knee pain associated with mild to moderate osteoarthritis (OA). The average infusion volume was 4 mL, administered at three doses four weeks apart. Given that platelet-derived growth factors promote the proliferation of chondrocytes and mesenchymal stem cells, leading to the stimulation of articular cartilage remodeling, further studies are warranted to assess the optimal platelet count necessary for the long-term effects of PRP in knee cartilage healing and sustained symptomatic improvement.

Randomized Controlled Trials for Platelet-Rich Plasma Use in Knee Osteoarthritis Rarely Report Key Sociodemographic Patient Variables: A Scoping Review

Purpose

To investigate the characteristics and rate of sociodemographic variables reported in randomized controlled trials (RCTs) studying platelet-rich plasma (PRP) injections in the treatment of knee osteoarthritis (OA).

Methods

In January 2024, PubMed, Scopus, and Web of Science databases were queried for the phrase "Platelet-Rich Plasma Knee Osteoarthritis." Included studies were RCTs investigating PRP use in knee OA published in English between 2012 and 2023. Each RCT was inspected for patient age and sex or gender as well as the following sociodemographic variables: race, ethnicity, insurance status, income, housing status, work status, and education. Data were presented in a descriptive fashion and analyzed using χ2 test and Fisher's exact test to compare 2 and 3 categorical variables, respectively, with significance defined as P < .05.

Results

From 2012 through 2023, 71 RCTs met inclusion criteria. Included publications reported both age and sex or gender in 71/71 papers (100%). Reporting rates for other sociodemographic variables were as follows: race (3/71, 4.23%), work status (5/71, 7.04%), and education (3/71, 4.23%). No studies included the ethnicity, insurance status, income, or housing status of the enrolled patients. There was no difference in reporting sociodemographic variables by journal (P = .083) or by year of publication (P = .340). Sociodemographic variables were reported significantly less frequently than age and sex or gender (P < .001).

Conclusions

In this study, we found that age and sex or gender are always reported in RCTs of PRP use for knee OA. However, other sociodemographic variables, such as race, work status, and education, that may be important to understand are rarely reported.

Clinical Relevance

Sociodemographic variables may affect outcomes in knee osteoarthritis. It is important to understand which of these variables are most studied and which variables are most overlooked. This will help us better understand the quality of the available information.

Influence of Platelet Concentration on the Clinical Outcome of Platelet-Rich Plasma Injections in Knee Osteoarthritis

BACKGROUND

Platelet-rich plasma (PRP) is one of the most frequently used orthobiologic products for the injection treatment of patients affected by knee osteoarthritis (OA). Some preliminary evidence supports the influence of platelet concentration on patients' clinical outcomes.

PURPOSE

To analyze if platelet concentration can influence the safety and clinical efficacy of PRP injections for the treatment of patients with knee OA.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study consisted of 253 patients with knee OA (142 men, 111 women; mean ± SD age, 54.8 ± 11.4 years; Kellgren-Lawrence grades 1-3) who were treated with 3 intra-articular injections of 5 mL of autologous leukocyte-rich or leukocyte-poor PRP. All patients were prospectively evaluated at baseline and at 2, 6, and 12 months. Patients were clinically assessed thorough the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales and the International Knee Documentation Committee (IKDC) Subjective score. Platelet concentration was correlated with clinical outcome. Further analysis was performed by stratifying patients into 3 groups (homogeneous for OA severity) based on platelet concentration (high, medium, and low). All complications and adverse events were reported, as well as failures.

RESULTS

An overall statistically significant improvement in all clinical scores was documented from baseline to each follow-up evaluation. Platelet concentration positively correlated with clinical outcome. KOOS Pain improved more with higher platelet concentration at 2 months (P = .036; rho = 0.132), 6 months (P = .009; rho = 0.165), and 12 months (P = .014; rho = 0.155). The same trend was shown by the other KOOS subscales and by the IKDC Subjective score, as well as by the comparison of the groups of high-, medium-, and low-platelet PRP. The highest failure rate (15.0%) was found in the low-platelet group as compared with the medium-platelet group (3.3%) and the high-platelet group (3.3%). No differences were observed among the 3 groups in terms of adverse events.

CONCLUSION

This study demonstrated that platelet concentration influences the clinical outcome of PRP injections in knee OA treatment. PRP with a higher platelet concentration provides a lower failure rate and higher clinical improvement as compared with PRP with a lower platelet concentration, with overall better results up to 12 months of follow-up in patients with knee OA.

Leukocytes Do Not Influence the Safety and Efficacy of Platelet-Rich Plasma Injections for the Treatment of Knee Osteoarthritis: A Double-Blind Randomized Controlled Trial

BACKGROUND

Platelet-rich plasma (PRP) is increasingly used for the injection treatment of knee osteoarthritis (OA). However, the role of leukocytes contained in PRP is controversial, with some preclinical studies suggesting detrimental effects and others emphasizing their contribution in secreting bioactive molecules.

PURPOSE

To compare the safety and effectiveness of leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) for the treatment of knee OA.

HYPOTHESIS

That leukocytes could influence results both in terms of adverse events and clinical outcomes.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

This double-blind randomized controlled trial included 132 patients with Kellgren-Lawrence grade 1-3 knee OA who were randomized to a 3-injection cycle of either LR-PRP or LP-PRP. Patients were prospectively assessed at baseline and at 2, 6, and 12 months with subjective evaluations comprising the International Knee Documentation Committee (IKDC) subjective score, the KOOS (Knee injury and Osteoarthritis Outcome Score), the WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), the visual analog scale for pain, the EuroQol-visual analog scale, the EuroQol-5 dimensions, and the Tegner activity scale. Objective evaluations consisted of the IKDC objective score, active/passive range of motion, and circumference of the index and contralateral knees. Patient judgment of the treatment was recorded as well as adverse reactions and failures.

RESULTS

An overall improvement in subjective and objective outcomes was documented, with no differences between the 2 groups, except for the improvement in the IKDC subjective score at 2 months, which was greater for the LR-PRP group compared with the LP-PRP group (14.8 ± 14.8 vs 8.6 ± 13.3, respectively; P = .046), as well as for active (P = .021) and passive (P = .040) ROM of the index knee at 6 months, showing statistically significant higher values in the LP-PRP group; and for quadriceps circumference of the index (P = .042) and contralateral (P = .045) knees at 12 months, which were significantly greater in the LR-PRP group. The IKDC subjective score improved from 42.5 ± 17.6 at baseline to 55.6 ± 21.4 at 12 months for the LR-PRP group (P < .0005) and from 45.7 ± 16.4 to 55.3 ± 20.4 for the LP-PRP group (P = .001). No differences in terms of patient treatment judgment were observed at all follow-up time points. No severe adverse events related to the treatment were reported, but some mild adverse events related to the treatment were observed: 16 in the LR-PRP group and 17 in the LP-PRP group. Treatment failed in 5 patients in the LR-PRP group and 2 in the LP-PRP group.

CONCLUSION

This double-blind randomized controlled trial demonstrated that leukocytes did not affect the safety and efficacy of intra-articular PRP injections for the treatment of patients with knee OA. Both LR-PRP and LP-PRP demonstrated comparable clinical outcomes at all follow-up time points, without showing differences in subjective and objective outcomes or in adverse events and treatment failures.

REGISTRATION

NCT04187183 (ClinicalTrials.gov).

Regenerative Inflammation: The Mechanism Explained from the Perspective of Buffy-Coat Protagonism and Macrophage Polarization

The buffy-coat, a layer of leukocytes and platelets obtained from peripheral blood centrifugation, plays a crucial role in tissue regeneration and the modulation of inflammatory responses. This article explores the mechanisms of regenerative inflammation, highlighting the critical role of the buffy-coat in influencing macrophage polarization and its therapeutic potential. Macrophage polarization into M1 and M2 subtypes is pivotal in balancing inflammation and tissue repair, with M1 macrophages driving pro-inflammatory responses and M2 macrophages promoting tissue healing and regeneration. The buffy-coat's rich composition of progenitor cells, cytokines, and growth factors-such as interleukin-10, transforming growth factor-β, and monocyte colony-stimulating factor-supports the transition from M1 to M2 macrophages, enhancing tissue repair and the resolution of inflammation. This dynamic interaction between buffy-coat components and macrophages opens new avenues for therapeutic strategies aimed at improving tissue regeneration and managing inflammatory conditions, particularly in musculoskeletal diseases such as osteoarthritis. Furthermore, the use of buffy-coat-derived therapies in conjunction with other regenerative modalities, such as platelet-rich plasma, holds promise for more effective clinical outcomes.

Evaluating Synergistic Effects of Hyaluronic Acid, Human Umbilical Cord-Derived Mesenchymal Stem Cells, and Growth Hormones in Knee Osteoarthritis: A Multi-Arm Randomized Trial

BACKGROUND

Knee osteoarthritis (OA) significantly affects quality of life and imposes economic burdens due to its prevalence and the disability it causes. The efficacy of current treatments is limited to alleviating the symptoms, and they cannot be used for regenerative purposes. This study aims to evaluate the efficacy and safety of combining hyaluronic acid (HA), human umbilical cord-derived mesenchymal stem cells (hUC-MSCs), and synthetic human growth hormone (somatotropin) in the treatment of knee OA, assessing pain relief, functional improvement, and cartilage regeneration.

METHODS

A four-arm, double-blind randomized trial was conducted with 51 knees from 28 subjects aged ≥50 with primary knee OA. The treatments involved were HA alone, HA with hUC-MSCs, HA with somatotropin, and a combination of all three. Efficacy was measured through the International Knee Documentation Committee (IKDC) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and visual analog score (VAS), and MRI T2 mapping of cartilage was conducted on pre-implantation at the 6th and 12th month.

RESULTS

All treatment arms showed improvements in the VAS and WOMAC scores over 12 months, suggesting some pain relief and functional improvement. However, MRI T2 mapping showed no significant cartilage regeneration across the groups.

CONCLUSIONS

While the combined use of HA, hUC-MSCs, and somatotropin improved symptoms of knee OA, it did not enhance cartilage regeneration significantly. This study highlights the potential of these combinations for symptom management but underscores the need for further research to optimize these therapies for regenerative outcomes.

Platelet-Rich Plasma Versus Alternative Injections for Osteoarthritis of the Knee: A Systematic Review and Statistical Fragility Index-Based Meta-analysis of Randomized Controlled Trials

BACKGROUND

Based in part on the results of randomized controlled trials (RCTs) that suggest a beneficial effect over alternative treatment options, the use of platelet-rich plasma (PRP) for the management of knee osteoarthritis (OA) is widespread and increasing. However, the extent to which these studies are vulnerable to slight variations in the outcomes of patients remains unknown.

PURPOSE

To evaluate the statistical fragility of conclusions from RCTs that reported outcomes of patients with knee OA who were treated with PRP versus alternative nonoperative management strategies.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 2.

METHODS

All RCTs comparing PRP with alternative nonoperative treatment options for knee OA were identified. The fragility index (FI) and reverse FI were applied to assess the robustness of conclusions regarding the efficacy of PRP for knee OA. Meta-analyses were performed to determine the minimum number of patients from ≥1 trials included in the meta-analysis for which a modification on the event status would change the statistical significance of the pooled treatment effect.

RESULTS

In total, this analysis included outcomes from 1993 patients with a mean ± SD age of 58.0 ± 3.8 years. The mean number of events required to reverse significance of individual RCTs (FI) was 4.57 ± 5.85. Based on random-effects meta-analyses, PRP demonstrated a significantly higher rate of successful outcomes when compared with hyaluronic acid (P = .002; odds ratio [OR], 2.19; 95% CI, 1.33-3.62), as well as higher rates of patient-reported symptom relief (P = .019; OR, 1.55; 95% CI, 1.07-2.24), not requiring a reintervention after the initial injection treatment (P = .002; OR, 2.17; 95% CI, 1.33-3.53), and achieving the minimal clinically important difference (MCID) for pain improvement (P = .007; OR, 6.19; 95% CI, 1.63-23.42) when compared with all alternative nonoperative treatments. Overall, the mean number of events per meta-analysis required to change the statistical significance of the pooled treatment effect was 8.67 ± 4.50.

CONCLUSION

Conclusions drawn from individual RCTs evaluating PRP for knee OA demonstrated slight robustness. On meta-analysis, PRP demonstrated a significant advantage over hyaluronic acid as well as improved symptom relief, lower rates of reintervention, and more frequent achievement of the MCID for pain improvement when compared with alternative nonoperative treatment options. Statistically significant pooled treatment effects evaluating PRP for knee OA are more robust than approximately half of all comparable meta-analyses in medicine and health care. Future RCTs and meta-analyses should consider reporting FIs and fragility quotients to facilitate interpretation of results in their proper context.

Orthobiologics in knee osteoarthritis, dream or reality?

Cartilage restoration or repair, also known as orthobiologic therapy, is indicated after the failure of conservative or supportive treatment. However, there is paucity in evidence supporting the efficacy of orthobiologic therapy. The blood-derived products, such as platelet-rich plasma (PRP), is one of the commonly used orthobiologic therapy for knee osteoarthritis. Several studies have shown that PRP is superior to other treatments, but the anatomic changes are scarce. Treatment with mesenchymal stem cells (MSCs) offers the greatest potential for curing degenerative disease due to their self-renewal ability, ability to migrate towards injured tissues (homing/trafficking), and ability to promote repair and regeneration of osteochondral defects. However, ethical concerns and high costs remain major challenges associated with MSC therapy. Gene therapy, another promising orthobiologic therapy, is currently in phase II clinical trial and has shown promising results. The key factors for successful orthobiologic therapy include patient selection, appropriate dosing, treatment of underlying mechanical problems, age, severity, and cost-effectiveness.

Platelet-rich plasma intra-articular knee injections from open preparation techniques do not pose a higher risk of joint infection: A systematic review of 91 randomized controlled trials and 5914 injections

Purpose

To compare the infection rate of intraarticular platelet-rich plasma (PRP) knee injections between open and closed techniques in randomized controlled trials (RCTs) published in the last decade.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, PubMed, Scopus and Virtual Health Library were accessed in October 2022 using the terms 'platelet-rich plasma', 'PRP', 'knee' and 'tibiofemoral' alone and in combination with Boolean operators AND/OR. RCTs published during the last 10 years evaluating PRP intra-articular knee injections were considered eligible. Studies were excluded if the kit/preparation technique was not described. Data were presented using individual studies' absolute values, totals, and pooled percentages. Publication bias was assessed using the ROBIS tool.

Results

Ninety-one studies met the predetermined eligibility criteria. Forty-one implemented a closed technique, while 50 were open. All studies implementing a closed technique disclosed their commercial kits. Only 16 studies (17.58%) failed to report joint infections. Among the studies reporting joint infections as outcomes, 30 implemented a closed technique with 1195 patients, 1921 intra-articular knee injections and 95.44% of patient follow-up. On the other hand, 45 of them implemented an open technique with 2290 patients, 3993 intra-articular knee injections and 97.07% of patient follow-up. No patient had a joint infection among the included studies. Thirty-three studies prepared their PRP in controlled environments (36.26%). Most studies did not report where the preparation occurred (48.35%). Only twelve studies disclosed using laminar flow during preparation (13.19%). The infection rate for both techniques was 0 per 1000 knee injections.

Conclusion

Open PRP preparation techniques do not pose a higher risk of joint infection and can lower manufacturing costs when appropriate facilities are available. However, PRP preparation setting and laminar flow implementation data are deficient, and minimal requirements for good manufacturing practices demand further studies while adhering to local and regional regulations.

Level of Evidence

Level I, systematic review of RCTs.

Extracorporeal shockwave therapy in the management of knee osteoarthritis: A systematic review of dose-response meta-analysis

Introduction

The aim of the research was to conduct a systematic review of dose-response meta-analysis, examining the correlation between the energy of extracorporeal shockwave therapy (ESWT) and clinical outcomes for patients with knee osteoarthritis (OA).

Methods

We conducted a systematic review of three online databases - PubMed, Embase, and Cochrane Library - to collect relevant articles from their inception to May 2023. We included the articles that investigated the efficacy of ESWT in treating knee OA and were designed using randomized controlled trials (RCTs). The main outcomes were measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for primary outcomes and the Visual Analog Scale (VAS) for secondary outcomes. We conducted a dose-response meta-analysis to examine the correlation between the energy of ESWT and clinical outcomes.

Results

Our study included a total of 7 RCTs (comprising 450 subjects) that met the inclusion criteria. We found a negative linear relationship between the doses of ESWT and WOMAC scores at the 1-week (p = 0.0398) and 4-week (p = 0.001) follow-up periods, but not at the 12-week follow-up period (p = 0.202). Furthermore, at the 4-week (p = 0.0477) and 12-week (p < 0.001) follow-up periods, a negative linear connection was found between the ESWT dose and VAS scores, but not at the 1-week follow-up period (p = 0.2268).

Conclusions

Our results demonstrate a dose-response connection between the energy of ESWT and clinical outcomes. This suggests that using higher energy levels of ESWT to treat knee OA could lead to greater improvement in clinical outcomes compared to using lower energy levels.

Allogeneic platelet-rich plasma for knee osteoarthritis in patients with primary immune thrombocytopenia: A randomized clinical trial

The treatment of painful KOA in adult patients with ITP has not been well studied yet. We conducted a prospective, double-blind, randomized, placebo-controlled trial to evaluate the efficacy of intra-articular allogeneic PRP injections on symptoms and joint structure in patients with KOA and ITP. 80 participants were randomly allocated in a 1:1 ratio to allogeneic PRP group or saline group. The primary outcome was the WOMAC total score at 12 months post-injection. The number of patients in each group who achieved MCID of primary outcome showed a statistically significant difference only at 3-month (27/39 vs. 5/39, p = 0.001) and 6-month (15/39 vs. 3/38, p = 0.032). The difference in WOMAC total score exceeded the MCID only at 3 month (mean difference of -15.1 [95% CI -20.7 to -9.5], p < 0.001). Results suggest that allogeneic PRP was superior to placebo only with respect to symptoms at 3-month of follow-up.

The use of injectable orthobiologics for knee osteoarthritis: A European ESSKA-ORBIT consensus. Part 1-Blood-derived products (platelet-rich plasma)

PURPOSE

The aim of this European Society of Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA) consensus is to provide recommendations based on evidence and expert opinion to improve indications, decision-making and administration-related aspects when using blood-derived orthobiologics (for simplicity indicated as PRP-platelet-rich plasma-with PRP being the most common product) for the management of knee osteoarthritis (OA).

METHODS

Leading European expert clinicians and scientists were divided into a steering group, a rating group and a peer review group. The steering group prepared 28 question-statement sets divided into three sections: PRP rationale and indications, PRP preparation and characterisation and PRP protocol. The quality of the statements received grades of recommendation ranging from A (high-level scientific support) to B (scientific presumption), C (low-level scientific support) or D (expert opinion). The question-statement sets were then evaluated by the rating group, and the statements scored from 1 to 9 based on their degree of agreement with the statements produced by the steering group. Once a general consensus was reached between the steering and rating groups, the document was submitted to the peer review group who evaluated the geographic adaptability and approved the document. A final combined meeting of all the members of the consensus was held to produce the official document.

RESULTS

The literature review on the use of blood-derived products for knee OA revealed that 9 of 28 questions/statements had the support of high-level scientific literature, while the other 19 were supported by a medium-low scientific quality. Three of the 28 recommendations were grade A recommendations: (1) There is enough preclinical and clinical evidence to support the use of PRP in knee OA. This recommendation was considered appropriate with a strong agreement (mean: 8). (2) Clinical evidence has shown the effectiveness of PRP in patients for mild to moderate degrees of knee OA (KL ≤ 3). This recommendation was considered appropriate with a strong agreement (mean: 8.1). (3) PRP injections have been shown to provide a longer effect in comparison to the short-term effect of CS injections. They also seem to provide a safer use profile with less potential related complications. This recommendation was considered appropriate with a very strong agreement (mean: 8.7). Six statements were grade B recommendations, 7 were grade C and 12 were grade D. The mean rating score was 8.2 ± 0.3.

CONCLUSIONS

The consensus group reached a high level of agreement on all the questions/statements despite the lack of clear evidence for some questions. According to the results from this consensus group, given the large body of existing literature and expert opinions, PRP was regarded as a valid treatment option for knee OA and as a possible first-line injectable treatment option for nonoperative management of knee OA, mainly for KL grades 1-3.

LEVEL OF EVIDENCE

Level II.

Comparative effectiveness of intra-articular therapies in knee osteoarthritis: a meta-analysis comparing platelet-rich plasma (PRP) with other treatment modalities

INTRODUCTION

Knee osteoarthritis (KOA) is a progressive joint disease commonly treated with intra-articular injections, including platelet-rich plasma (PRP), hyaluronic acid (HA), or corticosteroids (CS). This updated meta-analysis aims to enhance the statistical power of the results and provide comprehensive clinical evidence that reflects the most current research. By doing so, the authors aim to suggest a reliable estimate for the development of guidelines, addressing the pressing need for effective and minimally invasive treatment options.

METHODS

PubMed, Scopus, clinicaltrials.gov, Cochrane Central were searched until March 2023, for randomized controlled trials (RCTs) comparing the effectiveness of intra-articular injectable therapies, including PRP, HA, CS, and placebo, in KOA. Data extraction involved baseline characteristics and outcome measures [Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores, Visual Analog Scale (VAS) pain scores, KOOS, and IKDC scores] at 1, 3, 6 and 12 months. Statistical analysis, including subgroup analysis, assessment of heterogeneity, and publication bias, was conducted using Review Manager.

RESULTS

Our meta-analysis of 42 studies involving 3696 patients demonstrated that PRP treatment resulted in significant pain relief compared to HA injections, as evidenced by improved WOMAC pain (MD: -0.74; 95% CI: -1.02 to -0.46; P≤0.00001; I 2=94%) and VAS pain (MD: -0.65; 95% CI: -1.24 to -0.06; P=0.03; I2=97%) outcomes. Similarly, PRP showed greater efficacy in reducing WOMAC pain (MD: -8.06; 95% CI: -13.62 to -2.51: P=0.004; I 2=96%) and VAS pain (MD: -1.11; 95% CI: -1.64 to -0.59; P≤0.0001; I 2=68%) compared to CS injections, with the most significant improvement observed at 6 months.

CONCLUSIONS

PRP is an effective treatment for KOA. It provides symptomatic relief, has the potential to reduce disease progression, and has sustained effects up to 12 months. PRP offers superior pain relief and functional enhancement compared to CS and HA injections.

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.

Efficacy and Long-Term Outcomes of Intra-Articular Autologous Micro-Fragmented Adipose Tissue in Individuals with Glenohumeral Osteoarthritis: A 36-Month Follow-Up Study

BACKGROUND

Glenohumeral osteoarthritis (GOA) is associated with disabling shoulder pain that affects everyday life. Its management comprises various treatment approaches, both conservative and surgical. Regenerative medicine has gained a major role in the conservative treatment of osteoarthritis. Intra-articular injection of adipose-derived mesenchymal stem cells (ADMSCs) is a widely used regenerative medicine approach. The aim of this retrospective study was to report the safety and clinical outcomes of intra-articular injection of ADMSCs in patients with GOA over 36-months.

METHODS

This retrospective observational study involved patients with chronic shoulder pain resistant to standard conservative treatment and a diagnosis of concentric GOA, who received an intra-articular injection of autologous micro-fragmented adipose tissue (μFAT). The values of the Constant-Murley score (CMS), the visual analog scale (VAS), and the simple shoulder test (SST), collected at baseline and at 12, 24, and 36 months, were analyzed to assess treatment efficacy. The single assessment numeric evaluation (SANE) was used to rate patient satisfaction. The Friedman test was used to compare observations of CMS, VAS, and SST values repeated on the same subjects. The significance threshold was set at 0.05.

RESULTS

The participants were 65 patients with a mean age of 54.19 years and a nearly equal gender distribution. Most had mild concentric GOA classified as Samilson-Prieto grade 1. The mean follow-up duration was 44.25 months. The postoperative clinical scores showed significant improvement. At 36 months, the CMS was 84.60, the VAS score was 3.34, and the SST score was 10.15 (all p < 0.0001). The SANE score at 36 months indicated that 54 patients (83.08%) were completely satisfied with the treatment.

CONCLUSION

ADMSC treatment exerted favorable effects on the clinical outcomes of patients with GOA, providing pain relief and improving shoulder function. Our data support its use as a conservative treatment option for 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.

A model-based quantitative analysis of efficacy and associated factors of platelet rich plasma treatment for osteoarthritis

OBJECTIVE

While platelet rich plasma (PRP) has been extensively studied in treating osteoarthritis (OA), there has been an ongoing debate regarding the efficacy of PRP and the optimal subpopulation for PRP treatment remains unknown. The authors hereby aim to establish a pharmacodynamic model-based meta-analysis to quantitatively evaluate PRP efficacy, comparing with hyaluronic acid (HA) and identify relevant factors that significantly affect the efficacy of PRP treatment for OA.

METHODS

The authors searched for PubMed and the Cochrane Library Central Register of Controlled Trials of PRP randomized controlled trials (RCTs) for the treatment of symptomatic or radiographic OA from the inception dates to 15 July 2022. Participants' clinical and demographic characteristics and efficacy data, defined as Western Ontario and McMaster Universities Osteoarthritis Index and visual analog scale pain scores at each time point were extracted.

RESULTS

A total of 45 RCTs (3829 participants) involving 1805 participants injected with PRP were included in the analysis. PRP reached a peak efficacy at ~ 2-3 months after injection in patients with OA. Both conventional meta-analysis and pharmacodynamic maximal effect models showed that PRP was significantly more effective than HA for joint pain and function impairment (additional decrease of 1.1, 0.5, 4.3, and 1.1 scores compared to HA treatment at 12 months for Western Ontario and McMaster Universities Osteoarthritis Index pain, stiffness, function, and visual analog scale pain scores, respectively). Higher baseline symptom scores, older age (≥60 years), higher BMI (≥30), lower Kellgren-Lawrence grade (≤2) and shorter OA duration (<6 months) were significantly associated with greater efficacy of PRP treatment.

CONCLUSION

These findings sugges t that PRP is a more effective treatment for OA than the more well-known HA treatment. The authors also determined the time when the PRP injection reaches peak efficacy and optimized the targeting subpopulation of OA. Further high-quality RCTs are required to confirm the optimal population of PRP in the treatment of OA.

Нетрадиційні методи лікування остеоартрозу колінного суглоба

Сьогодні лікування остеоартрозу (ОА), як і раніше, є серйозною проблемою для медицини. Незважаючи на те, що багато широко використовуваних консервативних методів лікування ОА колінного суглоба визнані ефективними, триває пошук нових методів. Оскільки суглобовий хрящ має обмежений потенціал відновлення, ефективні методи лікування залишаються складними актуальними завданнями. Інноваційна терапія спрямована на пошук найкращого способу лікування для уповільнення прогресування ОА. Актуальними є епідеміологічні та клінічні дослідження ОА, оскільки епідеміологічні дослідження виявляють фактори ризику виникнення і прогресування цього захворювання, а клінічні дослідження відіграють важливу роль для нових методів лікування ОА, включно з пероральною, ін’єкційною та внутрішньосуглобовою терапією. Сьогодні провідні фахівці з лікування ОА продовжують дискутувати щодо корисності внутрішньосуглобових ін’єкцій (ВСІ) та доходять різних висновків. Мета дослідження: провести огляд літератури про лікування ОА колінного суглоба з аналізом інноваційних методів лікування щодо використання внутрішньосуглобових ін’єкцій (як-от: збагачена тромбоцитами плазма, терапія стовбуровими клітинами, пролотерапія, блокада генікулярного (колінного) нерва) та їх переваг і недоліків задля визначення можливих напрямків лікування, які є більш безпечними й економічно ефективними для пацієнта. Матеріали та методи. Пошук наукової інформації проведений в електронних базах PubMed, Google Scholar. Результати. У цьому огляді наведені методи лікування ОА із застосуванням внутрішньосуглобових ін’єкцій біологічно-фармакологічних засобів, як-от: збагачена тромбоцитами плазма, терапія стовбуровими клітинами та пролотерапія, блокада генікулярного нерва. Висновки. Зважаючи на мультидисциплінарний підхід, що включає біофармакологічні та немедикаментозні методи лікування ОА, внутрішньосуглобові ін’єкції можна розглядати як ефективну місцеву терапію ОА.

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.

The use of platelet-rich plasma in studies with early knee osteoarthritis versus advanced stages of the disease: a systematic review and meta-analysis of 31 randomized clinical trials

INTRODUCTION

Reports have concluded that platelet-rich plasma (PRP) is an effective and safe biological approach to treating knee osteoarthritis (OA). However, the effectiveness of PRP in advanced stages of the disease is not entirely clear. The purpose of this study was to evaluate whether the use of PRP would be as effective in studies with early-moderate knee OA patients compared to studies including patients with end-stage OA, based on the Kellgren-Lawrence classification.

MATERIALS AND METHODS

A comprehensive search in MEDLINE, EMBASE, Scopus, and Web of Science databases was conducted to identify randomized controlled trials (RCTs) comparing the effect of PRP injections versus other intra-articular treatments on pain and functionality. A meta-analysis was conducted using a random-effects model and the generic inverse variance method.

RESULTS

We included 31 clinical trials that reported data of 2705 subjects. Meta-analysis revealed an overall significant improvement of both pain [MD, - 1.05 (95% CI - 1.41 to - 0.68); I² = 86%; P ≤ 0.00001] and function [SMD, - 1.00 (95% CI - 1.33, to - 0.66); I² = 94%; P ≤ 0.00001], favoring PRP. Subanalysis for pain and functional improvement showed a significant pain relief in studies with 1-3 and 1-4 Kellgren-Lawrence OA stages and a significant functional improvement in studies with 1-2, 1-3 and 1-4 knee OA stages, favoring PRP.

CONCLUSION

Our results indicate that including patients with advanced knee OA does not seem to affect the outcomes of clinical trials in which the effectiveness of the PRP in knee OA is assessed.

Platelet-Rich Plasma for Intra-articular Injections: Preclinical and Clinical Evidence

The use of platelet-rich plasma (PRP) has been supported by encouraging data from in vitro and preclinical in vivo studies, both in terms of safety and efficacy. This led to the wide use of PRP injections in the clinical practice, with promising results especially as a minimally invasive treatment for cartilage degeneration and osteoarthritis (OA). While many controversies remain on the best PRP formulation, the overall available clinical studies support the benefits of PRP, with functional improvement and reduction of pain-related symptoms up to 12 months, especially in young patients and early OA stages.

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.

The role of Platelet-Rich Plasma (PRP) intraarticular injections in restoring articular cartilage of osteoarthritic knees. A systematic review and meta-analysis

Objective

To assess the effect of PRP on knee articular cartilage content (thickness/volume) and examine the correlation between cartilage changes and clinical outcomes in patients with knee OA.

Method

A systematic literature search was performed using the Cochrane methodology in four online databases. Studies were included if they reported on cartilage content with cross-sectional imaging pre- and post-injection. A random-effects model meta-analysis was performed. Correlation with clinical outcomes was evaluated.

Results

14 studies (n ​= ​1099 patients) from 1452 records met the inclusion criteria: seven RCTs (n ​= ​688), one prospective (n ​= ​50), one retrospective (n ​= ​68), and four case-series (n ​= ​224). The PRP preparation process and treatment protocol varied widely (follow-up 6-12 months). In meta-analysis, PRP treatment was not associated with a significant increase in cartilage thickness (4 studies, n ​= ​187, standardized mean difference: Hedges g: 0.079; 95%CI: 0.358 - 0.516; p ​= ​0.723). Meta-analysis of 3 RCTs (n ​= ​112) showed no significant difference in the change of overall knee cartilage content with PRP injections compared with no PRP (Hedges' g: 0.217; 95%CI: 0.177 - 0.611; P ​= ​0.281).

Conclusion

The current literature does not support the PRP as chondrogenic in treatment of knee OA. However, there is substantial heterogeneity in the evaluated studies which limits the robustness of any conclusion. An adequately powered RCT, with a standardized PRP regime and standardized high-resolution MRI is needed to definitely define any effect of PRP on knee cartilage content and its relation to clinical outcomes. Until such high-quality evidence becomes available, we recommend that PRP is not administered with the intention of promoting chondrogenesis.

Comparing efficacy of a single intraarticular injection of platelet-rich plasma (PRP) combined with different hyaluronans for knee osteoarthritis: a randomized-controlled clinical trial

BACKGROUND

Intraarticular plasma-rich platelet (PRP) and hyaluronic acid (HA) have each been shown to be effective for treating knee osteoarthritis (OA). Evidence supporting the combination therapy is controversial. This study aimed to investigate the efficacy of a single intraarticular PRP injection combined with different HAs in patients with knee OA.

METHODS

In this prospective randomized-controlled trial, 99 patients with Kellgren-Lawrence grade 2 knee OA with average knee pain ≥ 30 mm on a 0-100 mm pain visual analog scale (VAS) were randomized into two groups. The PRP + Artz group received a single intraarticular HA (Artz, 2.5 ml, 10 mg/ml) followed by 3 ml PRP (n = 50). The PRP + HYAJOINT Plus group received a single intraarticular cross-linked HA (HYAJOINT Plus, 3 ml, 20 mg/ml) followed by 3 ml PRP (n = 49). All patients were evaluated before and at 1, 3 and 6 months after injections. The primary outcome was the VAS pain reduction from baseline at 6 months. Secondary outcome measures included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lequesne index, single leg stance (SLS) test and patient satisfaction.

RESULTS

Ninety-five patients were analyzed by intention-to-treat analysis. Both groups improved significantly in VAS pain, WOMAC, Lequesne index and SLS at 1, 3 and 6 months post intervention (p < 0.05). Between-group comparisons showed no significant differences at most follow-up time points, except better improvements in Lequesne index at 1 month (p = 0.003) and WOMAC-stiffness score at 6 months (p = 0.020) in the PRP + Artz group, and superiority in SLS at 1, 3 and 6 months in the PRP+ HYAJOINT Plus group (p < 0.001, p = 0.003 and p = 0.004). Additional Johnson-Neyman analyses showed that among the patients with baseline WOMAC-pain score > 8.5, WOMAC-function score > 21.7 and WOMAC-total score > 32.0, respectively, those treated with PRP + HYAJOINT Plus injections had better effects in WOMAC-pain, WOMAC-function and WOMAC-total scores than those treated with PRP + Artz at 3 months postinjection (p < 0.05). Both groups reported high satisfaction. No serious adverse events occurred during the study.

CONCLUSIONS

A single PRP injection combined with Artz or HYAJOINT Plus is effective and safe for 6 months in patients with knee OA. Both injection regimens are potential treatment options for knee OA. Further studies are needed to confirm these results.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov (NCT04931719), retrospectively. Date of registration 18/6/2021.

NAME OF TRIAL REGISTRY

Comparing efficacy of single PRP combined with different hyaluronans for knee osteoarthritis.

LEVEL OF EVIDENCE

Therapeutic Level 1.

The Efficacy of Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis Symptoms and Structural Changes: A Systematic Review and Meta-Analysis

BACKGROUND

Platelet-rich plasma (PRP) usage in orthopedics continues to rise, despite guidelines suggesting non-superiority to comparative cohorts. Therefore, we performed a systematic review and meta-analysis on PRP efficacy using two clinical assessments: (1) Visual Analog Scale and (2) Western Ontario and McMaster Universities Osteoarthritis Index. We assessed consistency and clinical relevancy by determining study heterogeneity (eg, sample sizes, ages, body mass index, arthritic severities, etc.). Comparative cohorts were: (A) hyaluronic acid (HA); (B) corticosteroid (CS); (C) normal saline (NS); and (D) exercise therapy. We performed sub-analyses of structural changes assessed on ultrasound, radiograph, or magnetic resonance imaging .

METHODS

We utilized PubMed, Cochrane Library, and Embase databases up to December 1, 2021, according to Preferred Reporting Items for Systematic-Reviews and Meta-Analyses guidelines. Twenty-four studies met criteria, with comparisons to: HA (n = 11); CS (n = 6); NS (n = 5); and exercise therapy (n = 3). Seven studies assessed structural changes. Evaluations utilized a methodological scoring system. I² statistics and forest plots pooled analyses and delineated study results.

RESULTS

PRP led to Visual Analog Scale and Western Ontario and McMaster Universities Osteoarthritis Index improvements in most studies when compared to HA, CS, and NS (P ≤ .05). Comparison to exercise therapy resulted in inconclusive findings (P ≥ .05). However, substantial heterogeneity (I² ≥ 76%) was reported due to study variability. No differences were found when assessing structural changes or cartilage thickness by magnetic resonance imaging (standardized mean difference -0.01 [-0.19, 0.18], P = .91).

CONCLUSIONS

PRP may be associated with pain and functional improvements but was not clinically relevant (inconsistent study- and patient-metrics). In addition, PRP did not confer superiority when assessing knee-related structural changes.

Are leukocyte-poor or multiple injections of platelet-rich plasma more effective than hyaluronic acid for knee osteoarthritis? A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Platelet-rich plasma (PRP) has gained popularity as a treatment option for knee osteoarthritis; however, its efficacy remains controversial. The optimal leukocyte concentration and number of injections have not been well investigated. This study was, therefore, designed to provide clinical evidence on the leukocyte concentration and number of intra-articular injections of PRP via a meta-analysis of randomized controlled trials (RCTs).

METHODS

The MEDLINE, Embase, Cochrane Library, CINAHL, and Scopus databases were searched and RCTs comparing PRP and hyaluronic acid (HA) for treating knee osteoarthritis were included. Clinical outcomes, including visual analog scale (VAS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and adverse reactions, were evaluated.

RESULTS

A total of 138 studies were screened, of which 21 level 1 RCTs (2086 knees; 1077 PRP and 1009 HA) were included. PRPs showed significant improvement in pain according to the VAS score compared to HA at 6 and 12 months, regardless of leukocyte concentration. Both single and multiple injections of PRP improved pain better than HA at 12 months. Regarding function, both single and multiple injections of leukocyte-poor PRP and leukocyte-rich PRP led to significantly better improvement in total WOMAC score compared with HA at 6 months. There was no significant difference in procedure-related knee pain or swelling between the PRP and HA groups. Leukocyte-rich PRP had a significantly higher odds ratio for procedure-related knee pain or swelling compared to HA (odds ratio, 3.3 [95% confidence interval, 1.1-10.2], P = .037).

CONCLUSION

Based on evidence from Level 1 studies, intra-articular injection of PRP improves pain and function in patients with knee osteoarthritis for up to 12 months and is superior to HA, regardless of leukocyte concentration or number of injections. The findings of this study support the routine clinical use of intra-articular injections of PRP for the treatment of knee osteoarthritis, regardless of the type and frequency of PRP injection.

LEVEL OF EVIDENCE

Meta-analysis of level I studies.

Consensus Guidelines on Interventional Therapies for Knee Pain (STEP Guidelines) from the American Society of Pain and Neuroscience

Knee pain is second only to the back as the most commonly reported area of pain in the human body. With an overall prevalence of 46.2%, its impact on disability, lost productivity, and cost on healthcare cannot be overlooked. Due to the pervasiveness of knee pain in the general population, there are no shortages of treatment options available for addressing the symptoms. Ranging from physical therapy and pharmacologic agents to interventional pain procedures to surgical options, practitioners have a wide array of options to choose from - unfortunately, there is no consensus on which treatments are "better" and when they should be offered in comparison to others. While it is generally accepted that less invasive treatments should be offered before more invasive ones, there is a lack of agreement on the order in which the less invasive are to be presented. In an effort to standardize the treatment of this extremely prevalent pathology, the authors present an all-encompassing set of guidelines on the treatment of knee pain based on an extensive literature search and data grading for each of the available alternative that will allow practitioners the ability to compare and contrast each option.

Swiss Medical Devices for Autologous Regenerative Medicine: From Innovation to Clinical Validation

Regenerative medicine, based on the use of autologous tissues and embryonic, stem or differentiated cells, is gaining growing interest. However, their preparation, in a manner compliant with good practices and health regulations, is a technical challenge. The aim of this manuscript is to present the design of reliable CE marked medical devices for the preparation of standardized platelet-rich plasma (PRP) and other autologous biologics intended for therapeutic uses. There are numerous PRP isolation processes. Depending on the methodology used, PRP composition varies greatly in terms of platelet concentration, platelet quality, and level of contamination with red and white blood cells. This variability in PRP composition might affect the clinical outcomes. The devices presented here are based on a specific technology, patented all over the world, that allows the precise separation of blood components as a function of their density using thixotropic separator gels in closed systems. This allows the preparation, in an automated manner, of leukocyte poor PRP with a standardized composition. Production of different forms of PRP is a clinical asset to suit various therapeutic needs. Therefore, we are offering solutions to prepare PRP either in liquid or gel form, and PRP combined with hyaluronic acid. These biologics have been successfully used in many different therapeutic domains, resulting in more than 150 published clinical studies. We also developed the CuteCell technology platform for cell culture expansion for further autologous cell therapies. This technology enables the safe and rapid in vitro expansion of cells intended for therapeutic use in good manufacturing practices (GMP) and autologous conditions, using blood-derived products as culture media supplementation. We summarize in this article our 20 years’ experience of research and development for the design of PRP devices and, more recently, for PRP combined with hyaluronic acid.

Comparing the Efficacy of Intra-Articular Single Platelet-Rich Plasma(PRP) versus Novel Crosslinked Hyaluronic Acid for Early-Stage Knee Osteoarthritis: A Prospective, Double-Blind, Randomized Controlled Trial

Background and Objectives: For the treatment of knee osteoarthritis (OA), intra-articular platelet-rich plasma (PRP) and novel crosslinked single-dose hyaluronic acid (HA) have both been reported to improve outcomes, but no study has compared them for the treatment of knee OA. We hypothesized patients with early-stage knee OA who received PRP injections would have more WOMAC score changes than those who received HA injections. This is the first prospective, double-blind, parallel, randomized controlled trial comparing the efficacy of intra-articular single-dose PRP versus novel crosslinked HA (HyajointPlus) for treating early-stage knee OA. Materials and Methods: This study analyzed 110 patients randomized into the PRP (n = 54) or HA (n = 56) groups. The primary outcome is the change of WOMAC score at 1-, 3-, and 6-month follow-ups compared to baseline. Results: The data revealed significant improvements in all WOMAC scores in the PRP group at 1-, 3-, and 6-month follow-up visits compared with the baseline level except for the WOMAC stiffness score at the 1-month follow up. In the HA group, significant improvements were observed only in the WOMAC pain score for all the follow-up visits and in WOMAC stiffness, function, and total scores at 6-month follow-up. When comparing the change of WOMAC score at 1-, 3-, and 6-month follow-ups, no significant differences were found between PRP and HA group. Conclusions: This study revealed that both PRP and HA can yield significant improvements in WOMAC scores at 6-month follow-up without any between-group differences at 1-, 3-, and 6-month follow-ups. Thus, both the single-injection regimens of PRP and HA can improve the functional outcomes for treating early-stage knee OA.

Platelet Rich Plasma Injections for Knee Osteoarthritis Treatment: A Prospective Clinical Study

Background: The aim of this prospective study was to evaluate the efficacy and safety of Platelet Rich Plasma (PRP) injections in patients affected by knee osteoarthritis (KOA). An autologous blood product containing a high percentage of various growth factors (GFs), cytokines and modulating factors as PRP has shown promising results in achieving this goal. Methods: One hundred and fifty-three patients (72 males, mean age 59.06 ± 8.78, range 40−81 years old) from January 2018 to January 2020 received three consecutive PRP injections and completed the follow ups. Western Ontario and McMaster University Osteoarthritis index (WOMAC), Knee society score (KSS) and Visual Analogic Scale (VAS) were evaluated before PRP injection (T0), one month (T1), three months (T2) and six months (T3) after the treatment. All patients underwent baseline and at 6 months MRI and X-ray evaluation. Results: A statistically significant VAS, KSS and WOMAC reduction emerged in the comparison between evaluations (p < 0.05), MRI demonstrated non-statistically significant improvement in cartilage thickness for both tibial plate and femoral plate (p = 0.46 and p = 0.33 respectively), and no radiographic changes could be seen in any patients. Conclusions: PRP injection represents a valid conservative treatment to reduce pain, improve quality of life and functional scores even at midterm of 6 months follow-up.

Characterization of Microfragmented Adipose Tissue Architecture, Mesenchymal Stromal Cell Content and Release of Paracrine Mediators

The use of microfragmented adipose tissue (µFAT) for the treatment of musculoskeletal disorders, especially osteoarthritis (OA), is gaining popularity, following positive results reported in recent case series and clinical trials. Although these outcomes were postulated to rely on paracrine signals, to date, a thorough fingerprint of released molecules is largely missing. The purpose of this study was to first characterize both structure and cell content of unprocessed lipoaspirate (LA) and µFAT, and further identify and frame the array of signaling factors in the context of OA disease, by means of high throughput qRT-PCR for extracellular-vesicle (EV) embedded miRNAs and proteomics for tissue and secreted factors. Cell count showed reduction of blood cells in µFAT, confirmed by histological and flow cytometry analyses, that also showed a conserved presence of structural, endothelial and stromal components and pericytes. In the secretome, 376 and 381 EV-miRNAs in LA and µFAT, respectively, were identified. In particular, most abundant and µFAT upregulated EV-miRNAs were mainly recapitulating those already reported as ASC-EVs-specific, with crucial roles in cartilage protection and M2 macrophage polarization, while only a scarce presence of those related to blood cells emerged. Furthermore, secretome proteomic analysis revealed reduction in µFAT of acute phase factors driving OA progression. Taken together, these results suggest that processing of LA into µFAT allows for removal of blood elements and maintenance of tissue structure and stromal cell populations, and possibly the increase of OA-protective molecular features. Thus, microfragmentation represents a safe and efficient method for the application of adipose tissue properties in the frame of musculoskeletal disorders.

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.

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.

Leukocyte-Rich versus Leukocyte-Poor Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis: A Double-Blind Randomized Trial

BACKGROUND

Platelet-rich plasma (PRP) is gaining large interest in clinical practice as a minimally invasive injective treatment for knee osteoarthritis (OA). Different preparation methods are available, and the presence of leukocytes, deemed detrimental in some preclinical studies, is one of the most debated aspects regarding PRP efficacy.

PURPOSE

To compare the safety and effectiveness of leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) for the treatment of knee OA.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 192 patients with symptomatic knee OA (Kellgren-Lawrence grade 1-3) were randomly allocated to 3 weekly injections of LR-PRP or LP-PRP. LP-PRP was obtained with a filter for leukodepletion. LR-PRP and LP-PRP were divided into aliquots of 5 mL, with a mean platelet concentration of 1146.8 × 10⁹/L and 1074.9 × 10⁹/L and a mean leukocyte concentration of 7991.4 × 10⁶/L and 0.1 × 10⁶/L, respectively. Patients were evaluated at baseline and thereafter at 2, 6, and 12 months for the primary outcome, the International Knee Documentation Committee (IKDC) subjective score; and for secondary outcomes, the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, EuroQol-visual analog scale (EQ-VAS), and Tegner score.

RESULTS

No differences between groups were observed in terms of absolute values or improvement of the clinical scores across all follow-up intervals. The mean IKDC subjective score at baseline and 12 months improved from 45.6 to 60.7 in the LR-PRP group as compared with 46.8 to 62.9 in the LP-PRP group (P = .626). No severe adverse events were described in either group, although 15 mild adverse events (knee pain or swelling) were reported: 12.2% for LR-PRP and 4.7% for LP-PRP (P = .101). No statistically significant difference was also found between LR-PRP and LP-PRP in terms of failures (7.8% vs 3.5%, P = .331).

CONCLUSION

This double-blind randomized trial showed that 3 intra-articular LR-PRP or LP-PRP injections produced similar clinical improvement in the 12 months of follow-up in patients with symptomatic knee OA. Both treatment groups reported a low number of adverse events, without intergroup differences. The presence of leukocytes did not significantly affect the clinical results of PRP injections.

REGISTRATION

NCT02923700 (ClinicalTrials.gov identifier).