Intra-articular platelet-rich plasma for the treatment of osteoarthritis

Platelet-rich plasma augmentation in anterior cruciate ligament reconstruction: Evidence is still too scattered. A scoping review of randomised controlled trials

PURPOSE

Platelet-rich plasma (PRP) augmentation has been proposed to improve the results of anterior cruciate ligament reconstruction (ACLR). The present study aims to quantify the available evidence to support the use of PRP as biological augmentation in ACLR surgery.

METHODS

A systematic literature search was conducted on the PubMed, Cochrane, Web of Science and Embase databases on 10 March 2023. Inclusion criteria were randomised controlled trials (RCTs), written in English, addressing PRP augmentation in ACLR surgery, with no time limitation. A scoping review was performed to map the body of literature by examining the evidence related to specific aspects of patients' treatment and evaluation. Risk of bias evaluation was performed with the Cochrane risk-of-bias tool for randomised trials Version 2 (RoB 2), while the quality assessment was performed with the use of the Coleman Score.

RESULTS

Out of 983 articles retrieved, 23 RCTs on 943 knees were included in this scoping review. PRP was administered in a liquid form in nine studies and clotted in 11 studies, while in three studies both liquid and clotted PRP were used. Hamstring auto/allografts were used in 14 studies, patellar tendon auto/allografts were used in eight studies and one study described ACLR with peroneus longus allografts. The map of the evidence documented high heterogeneity also in terms of surgical technique, objective and subjective outcome measures and radiological assessment, as well as follow-up times ranging from 1 day to 2 years, with virtually no overlapping data among studies neither in terms of treatments nor evaluations. Risk of bias evaluation showed an overall low quality of the included studies.

CONCLUSIONS

The available literature addressing PRP augmentation in ACLR is largely scattered. PRP was produced and applied following different procedures, and high variability was detected across the included studies for every aspect of ACLR surgery and evaluation. Currently, a meaningful comparison of the available studies is not possible as the quantification of the literature results is biased by their heterogeneity. Future studies should provide more standardisation to investigate the benefits of biological augmentation in ACL surgery and confirm the promising yet weak evidence of PRP potential as well as the most suitable application modality, before routine use in clinical practice.

LEVEL OF EVIDENCE

Levels I and II, scoping review.

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.

Orthobiologics: Current role in Orthopedic Surgery and Traumatology

Orthobiologics are organic and synthetic materials that help in the cure of musculo-skeletal problems and are utilized in Orthopaedic Surgery, both in and out of the surgical theater, to augment the possibilities of curing bone and soft tissue lesions. Taking into account that their effect is frequently multifactorial and, in some occasions not entirely comprehended, together with the insufficient clinical information, orthobiologics should be scrupulously assessed against other secure and clinically accepted options. The fundamental orthobiologics today ready for use in Orthopedic Surgery are the following: osseous hollow fillers, extracellular matrix (ECM) substances, platelet-rich plasma (PRP), bone morphogenetic protein-2 (BMP-2), bone marrow aspirate (BMA), bone marrow aspirate concentrate (BMAC), and mesenchymal stem cells (MSCs). It is predictable that in the time to come we will have more secure and more efficacious orthobiologics. Meanwhile, it is paramount that orthopedic surgeons have appropriate information of contemporary orthobiologics (biological adjuvants) so that they can utilize them correctly.

Pooled Platelet-Rich Plasma Lysate Therapy Increases Synoviocyte Proliferation and Hyaluronic Acid Production While Protecting Chondrocytes From Synoviocyte-Derived Inflammatory Mediators

Platelet-rich plasma (PRP) preparations are being used with moderate success to treat osteoarthritis (OA) in humans and in veterinary species. Such preparations are hindered, however, by being autologous in nature and subject to tremendous patient and processing variability. For this reason, there has been increasing interest in the use of platelet lysate preparations instead of traditional PRP. Platelet lysate preparations are acellular, thereby reducing concerns over immunogenicity, and contain high concentrations of growth factors and cytokines. In addition, platelet lysate preparations can be stored frozen for readily available use. The purpose of this study was to evaluate the effects of a pooled allogeneic platelet-rich plasma lysate (PRP-L) preparation on equine synoviocytes and chondrocytes challenged with inflammatory mediators in-vitro to mimic the OA joint environment. Our hypothesis was that PRP-L treatment of inflamed synoviocytes would protect chondrocytes challenged with synoviocyte conditioned media by reducing synoviocyte pro-inflammatory cytokine production while increasing synoviocyte anti-inflammatory cytokine production. Synoviocytes were stimulated with either interleukin-1β (IL-1β) or lipopolysaccharide (LPS) for 24 h followed by no treatment or treatment with platelet-poor plasma lysate (PPP-L) or PRP-L for 48 h. Synoviocyte growth was evaluated at the end of the treatment period and synoviocyte conditioned media was assessed for concentrations of hyaluronic acid (HA), IL-1β, tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6). Chondrocytes were then challenged for 48 h with synoviocyte conditioned media from each stimulation and treatment group and examined for gene expression of collagen types I (COL1A1), II (COL2A1), and III (COL3A1), aggrecan (ACAN), lubricin (PRG4), and matrix metallopeptidase 3 (MMP-3) and 13 (MMP-13). Treatment of inflamed synoviocytes with PRP-L resulted in increased synoviocyte growth and increased synoviocyte HA and IL-6 production. Challenge of chondrocytes with conditioned media from PRP-L treated synoviocytes resulted in increased collagen type II and aggrecan gene expression as well as decreased MMP-13 gene expression. The results of this study support continued investigation into the use of pooled PRP-L for the treatment of osteoarthritis and warrant further in-vitro studies to discern the mechanisms of action of PRP-L.

Biologic agents for anterior cruciate ligament healing: A systematic review

AIM

To systematically review the currently available literature concerning the application of biologic agents such as platelet-rich plasma (PRP) and stem cells to promote anterior cruciate ligament (ACL) healing.

METHODS

A systematic review of the literature was performed on the use of biologic agents (i.e., PRP or stem cells) to favor ACL healing during reconstruction or repair. The following inclusion criteria for relevant articles were used: Clinical reports of any level of evidence, written in English language, on the use of PRP or stem cells during ACL reconstruction/repair. Exclusion criteria were articles written in other languages, reviews, or studies analyzing other applications of PRP/stem cells in knee surgery not related to promoting ACL healing.

RESULTS

The database search identified 394 records that were screened. A total of 23 studies were included in the final analysis: In one paper stem cells were applied for ACL healing, in one paper there was a concomitant application of PRP and stem cells, whereas in the remaining 21 papers PRP was used. Based on the ACL injury pattern, two papers investigated biologic agents in ACL partial tears whereas 21 papers in ACL reconstruction. Looking at the quality of the available literature, 17 out of 21 studies dealing with ACL reconstruction were randomized controlled trials. Both studies on ACL repair were case series.

CONCLUSION

There is a paucity of clinical trials investigating the role of stem cells in promoting ACL healing both in case of partial and complete tears. The role of PRP is still controversial and the only advantage emerging from the literature is related to a better graft maturation over time, without documenting beneficial effects in terms of clinical outcome, bone-graft integration and prevention of bony tunnel enlargement.