Intra-Articular Injection of Platelet-Rich Plasma Is More Effective than Hyaluronic Acid or Steroid Injection in the Treatment of Mild to Moderate Knee Osteoarthritis: A Prospective, Randomized, Triple-Parallel Clinical Trial

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.

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

BACKGROUND

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

HYPOTHESIS/PURPOSE

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

STUDY DESIGN

Systematic review; Level of evidence, 1.

METHODS

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

RESULTS

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

CONCLUSION

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

The Efficacy of Platelet-Rich Plasma Injection Therapy in Obese versus Non-Obese Patients with Knee Osteoarthritis: A Comparative Study

Background/Objectives: Obesity is a common comorbidity in knee osteoarthritis (KOA) patients. Platelet-Rich Plasma (PRP) injection therapy may mitigate KOA. To further clarify potential patient selection for PRP injection therapy, we compared the outcomes in patients with different body mass index (BMI). Methods: A total of 91 patients with mild to moderate KOA were treated with three intra-articular PRP injections at 10 to 14-day intervals. Range of motion (ROM), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Visual Analogue Scale (VAS) were documented before and after the injections at 15 days, 6 months, 12 months, and at the last follow-up. Outcomes were compared between patients with a BMI over 30 kg/m2 (obese, n = 34) and under 30 kg/m2 (non-obese, n = 57). Results: Significant difference during the follow-up was detected in WOMAC score at the last follow-up favouring BMI under 30 group [17.8 ± 18.8 versus 10.5 ± 11.7, p = 0.023]. The odds ratio (OR) in BMI over 30 kg/m2 group for total knee arthroplasty was 3.5 (95% CI 0.3-40.1, p = 0.553), and OR for any arthroplasty was 7.5 (95% CI 0.8-69.8, p = 0.085) compared to non-obese patients. Conclusions: Obese patients benefitted from PRP injections in KOA but there is a minimal difference favouring non-obese patients in symptom alleviation in follow-up stages after 12 months. The risk of arthroplasty is higher for obese KOA patients.

Most Publications Regarding Platelet-Rich Plasma Use in the Knee Are From Asia, Investigate Injection for Osteoarthritis, and Show Outcome Improvement: A Scoping Review

PURPOSE

To evaluate and synthesize the available literature related to platelet-rich plasma (PRP) treatment of knee pathologies and to provide recommendations to inform future research in the field.

METHODS

PubMed, CINAHL, and Scopus databases were queried on October 6, 2023. All identified citations were collated and uploaded into Covidence for screening and data extraction. Studies were included if they were human studies published in English with adult cohorts that received PRP as a procedural injection or surgical augmentation for knee pathologies with patient-reported outcome measures (PROMs) and level of evidence Levels I-IV.

RESULTS

Our search yielded 2,615 studies, of which 155 studies from 2006 to 2023 met the inclusion criteria. Median follow-up was 9 months (±11.2 months). Most studies (75.5%) characterized the leukocyte content of PRP, although most studies (86%) did not use a comprehensive classification scheme. In addition, most studies were from Asia (50%) and Europe (32%) and were from a single center (96%). In terms of treatment, 74% of studies examined PRP as a procedural injection, whereas 26% examined PRP as an augmentation. Most studies (68%) examined treatment of knee osteoarthritis. Many studies (83%) documented significant improvements in PROMs, including 93% of Level III/IV evidence studies and 72% of Level I/II evidence studies, although most studies (70%) failed to include minimal clinically important difference values. The visual analog scale was the most-used PROM (58% of studies), whereas the Short Form Health Survey 36-item was the least-used PROM (5% of studies).

CONCLUSIONS

Most published investigations of knee PRP are performed in Asia, investigate procedural injection for osteoarthritis, and show significant outcome improvements. In addition, this review highlights the need for better classification of PRP formulations.

LEVEL OF EVIDENCE

Level IV, scoping Review of level I-IV studies.

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.

Strategic application of imaging in DMOAD clinical trials: focus on eligibility, drug delivery, and semiquantitative assessment of structural progression

Despite decades of research efforts and multiple clinical trials aimed at discovering efficacious disease-modifying osteoarthritis (OA) drugs (DMOAD), we still do not have a drug that shows convincing scientific evidence to be approved as an effective DMOAD. It has been suggested these DMOAD clinical trials were in part unsuccessful since eligibility criteria and imaging-based outcome evaluation were solely based on conventional radiography. The OA research community has been aware of the limitations of conventional radiography being used as a primary imaging modality for eligibility and efficacy assessment in DMOAD trials. An imaging modality for DMOAD trials should be able to depict soft tissue and osseous pathologies that are relevant to OA disease progression and clinical manifestations of OA. Magnetic resonance imaging (MRI) fulfills these criteria and advances in technology and increasing knowledge regarding imaging outcomes likely should play a more prominent role in DMOAD clinical trials. In this perspective article, we will describe MRI-based tools and analytic methods that can be applied to DMOAD clinical trials with a particular emphasis on knee OA. MRI should be the modality of choice for eligibility screening and outcome assessment. Optimal MRI pulse sequences must be chosen to visualize specific features of OA.

The Influence of Body Mass Index on Growth Factor Composition in the Platelet-Rich Plasma in Patients with Knee Osteoarthritis

BACKGROUND

An abnormally high body mass index is strongly associated with knee osteoarthritis. Usually, obese patients are excluded from clinical trials involving PRP intra-articular injections. Growth factors have been demonstrated to have a disease-modifying effect on KOA treatment, even though data on their influence on treatment effectiveness in obese patients are lacking.

PURPOSE

To prospectively compare the level of selected growth factors including transforming growth factor-b (TGF-β), epidermal growth factor (EGF), fibroblast growth factor, insulin-like growth factor-1 (IGF-1), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and fibroblast growth factor-2 (FGF-2) in platelet-rich plasma (PRP) in obese patients and patients with normal BMI.

METHODS

A total of 49 patients were included in the study according to inclusion and exclusion criteria. The groups strongly differed in body mass index (median values 21.6 vs. 32.15). Concentrations of growth factors were measured with an enzyme-linked immunosorbent assay. Statistical significance was determined with the Mann-Whitney U test. The compliance of the distribution of the results with the normal distribution was checked using the Shapiro-Wilk test separately for both groups.

RESULTS

There were no statistically significant differences in median marker levels between groups. Statistically significant Pearson correlations were observed between IGF-1 serum level and age (weak negative, r = -0.294, p = 0.041) and gender (moderate positive, r = 0.392, 0.005).

CONCLUSIONS

BMI does not influence the level of selected growth factors in patients with knee osteoarthritis. Obese and non-obese patients had similar compositions of PDGF, TGF-β, EGF, FGF-2, IGF-1, and VEGF. PRP can be used in both groups with similar effects associated with growth factors' influence on articular cartilage.