Intra-articular injection with Autologous Conditioned Plasma does not lead to a clinically relevant improvement of knee osteoarthritis: a prospective case series of 140 patients with 1-year follow-up

Pain Management Strategies in Osteoarthritis

Pain is the major symptom of osteoarthritis (OA) and is an important factor in strategies to manage this disease. However, the current standard of care does not provide satisfactory pain relief for many patients. The pathophysiology of OA is complex, and its presentation as a clinical syndrome is associated with the pathologies of multiple joint tissues. Treatment options are generally classified as pharmacologic, nonpharmacologic, surgical, and complementary and/or alternative, typically used in combination to achieve optimal results. The goals of treatment are the alleviation of symptoms and improvement in functional status. Several studies are exploring various directions for OA pain management, including tissue regeneration techniques, personalized medicine, and targeted drug therapies. The aim of the present narrative review is to extensively describe all the treatments available in the current practice, further describing the most important innovative therapies. Advancements in understanding the molecular and genetic aspects of osteoarthritis may lead to more effective and tailored treatment approaches in the future.

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.

Autologous Conditioned Plasma (ACP) and Osteoarthritis of the Knee: A Review of Current Clinical Evidence

The primary objective of this study is to record the clinical outcomes of autologous conditioned plasma (ACP) for the treatment of knee osteoarthritis (OA) based on published literature. Multiple databases (PubMed, Embase, Web of Science and Scopus) were searched using terms for "knee OA" and the intervention "ACP" for articles published in English to January 4, 2024. All clinical studies using ACP for knee OA were included. Studies not utilizing ACP alone, i.e. used as an adjunct with other modalities or not focusing on the management of knee OA, were excluded. Five studies, three randomized controlled trials (RCTs) and two real-world post-market studies conducted in a clinical practice met the inclusion/exclusion criteria and were included in this study. All studies demonstrated statistically significant improvements in various patient-reported outcome measures (PROMs), however the studies performed in the clinical practice reported non-accomplishment of minimally clinically important difference (MCID). The results demonstrated the potential of ACP for management of knee OA, however the MCID was not achieved in real-world clinical settings. Thus, more adequately powered RCTs with longer follow-up as well as real-world post-market studies are warranted to establish long-term efficacy and justify routine clinical use, respectively, of ACP in patients suffering with knee OA.

Effect of Autologous Conditioned Plasma Injections in Patients With Knee Osteoarthritis

Background

Autologous conditioned plasma (ACP) is a commercially available platelet concentrate with promising results from clinical trials.

Purpose

To evaluate the clinical outcome after 3 consecutive injections of ACP in patients with knee osteoarthritis (OA) and study the influence of ACP composition and different patient factors as predictors of treatment effect.

Study Design

Case series; Level of evidence, 4.

Methods

This prospective case series included 260 patients (307 knees) who received ACP treatment for knee OA. The mean patient age was 51 ± 10 years. Improvement up to 12 months' follow-up was measured using the Knee injury and Osteoarthritis Outcome Score (KOOS). ACP composition was analyzed in 100 patients. The predictive value of age, sex, history of knee trauma, Kellgren-Lawrence OA grade, body mass index, and ACP composition was evaluated using generalized estimating equations.

Results

The mean overall KOOS improved from 38 ± 14 at baseline to 45 ± 18 at 3 months, 45 ± 18 at 6 months, and 43 ± 18 at 12 months (all P < .05); 40% of patients achieved an improvement above the minimal clinically important difference (MCID) of 8 after 6 months and 33% after 12 months. The variation in ACP composition did not correlate with KOOS (P > .05). Older age led to a greater clinical benefit (β = 0.27; P = .05), whereas bilateral treatment predicted worse outcomes (β = -5.6; P < .05).

Conclusion

The improvement in KOOS after treatment with ACP did not reach the MCID in most study patients. Older age was a predictor for better outcomes. The composition of ACP varied between patients but did not predict outcomes within the evaluated range. The study findings show the limited benefit of ACP treatment for knee OA and call for caution with routine use in clinical practice.

Modifying Orthobiological PRP Therapies Are Imperative for the Advancement of Treatment Outcomes in Musculoskeletal Pathologies

Autologous biological cellular preparations have materialized as a growing area of medical advancement in interventional (orthopedic) practices and surgical interventions to provide an optimal tissue healing environment, particularly in tissues where standard healing is disrupted and repair and ultimately restoration of function is at risk. These cellular therapies are often referred to as orthobiologics and are derived from patient's own tissues to prepare point of care platelet-rich plasma (PRP), bone marrow concentrate (BMC), and adipose tissue concentrate (ATC). Orthobiological preparations are biological materials comprised of a wide variety of cell populations, cytokines, growth factors, molecules, and signaling cells. They can modulate and influence many other resident cells after they have been administered in specific diseased microenvironments. Jointly, the various orthobiological cell preparations are proficient to counteract persistent inflammation, respond to catabolic reactions, and reinstate tissue homeostasis. Ultimately, precisely delivered orthobiologics with a proper dose and bioformulation will contribute to tissue repair. Progress has been made in understanding orthobiological technologies where the safety and relatively easy manipulation of orthobiological treatment tools has been demonstrated in clinical applications. Although more positive than negative patient outcome results have been registered in the literature, definitive and accepted standards to prepare specific cellular orthobiologics are still lacking. To promote significant and consistent clinical outcomes, we will present a review of methods for implementing dosing strategies, using bioformulations tailored to the pathoanatomic process of the tissue, and adopting variable preparation and injection volume policies. By optimizing the dose and specificity of orthobiologics, local cellular synergistic behavior will increase, potentially leading to better pain killing effects, effective immunomodulation, control of inflammation, and (neo) angiogenesis, ultimately contributing to functionally restored body movement patterns.

Real-world evidence to assess the effectiveness of platelet-rich plasma in the treatment of knee degenerative pathology: a prospective observational study

Objective:

The present work aims to analyse the effectiveness of platelet-rich plasma (PRP) in degenerative knee pathology based on real-world data and to evaluate possible factors influencing the response to treatment.

Methods:

In total, 531 cases were analysed collecting data on gender, age, body mass index, pathology location, severity, number of cycles and route of administration. Clinical outcome was evaluated at 6 and 15 months after treatment, using the Knee injury and Osteoarthritis Outcome Score (KOOS) and obtaining percentages of Minimal Clinically Important Improvement (MCII). Blood and PRP samples were randomly tested as a quality control measure to ensure the correct properties. Comparative statistical tests and multivariate regression were performed for the analysis of the variables.

Results:

The PRP applied had a platelet concentration factor of 1.67, with no leukocytes or erythrocytes. The percentage of patients with MCII at 6 and 15 months after PRP application was 59.32% and 70.62%, respectively. Patients with MCII were younger (p = 0.0246) and with lower body mass index (p = 0.0450). The treatment had a better response in mild/moderate cases than in severe cases (p = 0.0002). Intraosseous PRP application in severe cases improved the effect of intraarticular PRP (p = 0.0358). The application of a second cycle of PRP only improved the response in patients without MCII at 6 months (p = 0.0029), especially in mild/moderate cases (p = 0.0357).

Conclusion:

The applications of PRP in degenerative knee pathologies is an effective treatment, but this effectiveness nonetheless depends on several variables. Real-world data can complement that from clinical trials to provide valuable information.

Clinical outcome and risk factor predictive for failure of autologous PRP injections for low-to-moderate knee osteoarthritis

PURPOSE

To report the 5-year clinical efficacy of PRP intra articular injections in knee osteoarthritis (OA) and to investigate the risk factors predictive for treatment failure and poor clinical outcome.

METHODS

We retrospectively evaluated 118 patients treated for low to moderate knee OA demonstrated by X-Ray and magnetic resonance imaging (MRI) with autologous PRP injection from 2014 to 2018 with a mean 51.1 ± 14.8 (range 29 to 89) months follow-up. All the patients were evaluated with Lysholm and WOMAC score. The role of Kellgren Lawrence (KL) grade, patello-femoral (PF) degeneration, age, body mass index (BMI), relevant comorbilities, smoking status, gender, previous surgery or conservative measures were analyzed with univariate and multivariate analysis.

RESULTS

There was a significant improvement of all outcome measures at final follow-up and high satisfaction rate (79.7%). The overall failure rate was of 15.3% after a mean of 57.7 ± 15.1 (range 33 to 85) months. The BMI and the KL grade were identified as significant independent risk factor related to failure of autologous PRP injection. Patients under 60 reported significantly higher Tegner activity scale (p = 0.032) at final follow-up. Patients with KL grade 3 and patients with PF MRI-KL grade 3 had significantly lower Lysholm scores (p = 0.026 and p = 0.042 respectively) at final assessment. Younger patients with lower BMI and lower grade of radiographic OA had significantly longer therapeutic benefit (p < 0.05).

CONCLUSION

Intra articular PRP injections led to a significant clinical improvement in middle-aged adults with a low to moderate knee OA. BMI and high KL grade have been identified as significant risk factors predictive for failure at mid-term follow-up.

Editorial Commentary: Platelet-Rich Plasma and Hyaluronic Acid Injection for Knee Osteoarthritis Are Both Cost Effective

Knee osteoarthritis is associated with an annual cost to society exceeding US$27 billion. Value-based treatment is an important consideration, and cost-benefit analyses are crucial to determine the benefits to both patients and society. The quality-adjusted life year (QALY) is a generic measure of burden including both quality and quantity. Recent studies have suggested that intra-articular injection of platelet-rich plasma (PRP) is effective treatment for knee osteoarthritis and comparable to hyaluronic acid (HA). Although the costs (dollars) per QALY were higher for PRP ($8,635) than for HA ($5,331), PRP was more cost effective at 1 year and was associated with an incremental cost-effectiveness ratio (ICER) of $12,628 QALY. Similarly, the utility value (proportion of QALY compared with perfect health) of PRP was higher by 0.11 QALY: 0.69 versus 0.58.

PRP in wound healing applications

Platelets play a crucial role in hemostasis, tissue regeneration and host defense. Based on these settings, platelet-rich plasma (PRP) and its derivatives are therapeutically used to promote wound healing in several scenarios. This review summarizes the biological mechanisms underlying the most traditional as well as innovative applications of PRP in wound healing. These mechanisms involve the combined action of platelet-derived growth factors and cytokines, together with the role of plasma-derived fibrillar, antioxidant and homeostatic factors. In addition, regenerative treatments with PRP consist of personalized and non-standardized methods. Thus, the quality of PRP varies depending on endogenous factors (e.g., age; gender; concomitant medication; disease-associated systemic factors; nutrition) and exogenous factors (anticoagulants and cellular composition). This review also analyses whether these factors affect the biological mechanisms of PRP in wound healing applications.