Intraosseous infiltration of platelet-rich plasma for severe knee osteoarthritis

The Combined Intraosseous Administration of Orthobiologics Outperformed Isolated Intra-articular Injections in Alleviating Pain and Cartilage Degeneration in a Rat Model of MIA-Induced Knee Osteoarthritis

BACKGROUND

Intra-articular (IA) platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMAC) injections have shown efficacy and safety in treating osteoarthritis (OA). However, the effectiveness and mechanisms of combined intraosseous (IO) administration of these orthobiologics have yet to be explored.

PURPOSE/HYPOTHESIS

The purpose of this study was to evaluate the effect on pain, cartilage, synovium/infrapatellar fat pad (IFP), and subchondral bone in rat knee OA, comparing isolated IA with combined IA and IO (IA+IO) injections of PRP or BMAC. It was hypothesized that combined injections would be superior to sole IA injections.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 48 rats were divided into 6 groups: sham (only joint puncture during OA induction with IA+IO saline injection treatment) and 5 groups with OA induction, control (IA+IO saline injection), PRP (IA PRP+IO saline injection), BMAC IA (IA BMAC+IO saline injection), PRP IA+IO (IA+IO PRP injection), and BMAC IA+IO (IA+IO BMAC injection). OA was induced by IA injection of monosodium iodoacetate (MIA). Rats were administered different orthobiologics according to their grouping 3 weeks after the MIA injection. Pain changes were evaluated using the weightbearing ratio assay at weeks 3, 4, 5, 7, and 9 after OA induction. Rats were euthanized at week 9 for gross, radiological, histological, immunohistochemical, and immunofluorescence assessments of cartilage, synovium, and subchondral bone.

RESULTS

Compared with the control group, all orthobiologics injection groups had reduced joint pain. Compared with IA injection, IA+IO injections provided superior pain relief by suppressing calcitonin gene-related peptide and substance P in both the synovium/IFP and subchondral bone. IA+IO injections slowed the progression of subchondral bone lesions by inhibiting CD31hiEmcnhi vessel formation and excessive osteoclast and osteoblast turnover while preserving subchondral bone microarchitecture, slowing cartilage degeneration. However, IA+IO injections did not outperform isolated IA injections in reducing synovitis and synovium/IFP fibrosis. Compared with PRP, BMAC exhibited superior inhibition of pain-related mediators, but no significant differences were observed in synovitis suppression, infrapatellar fat pad fibrosis, and subchondral bone protection.

CONCLUSION

IA+IO injections of orthobiologics were more effective in relieving pain, slowing cartilage degeneration, and inhibiting abnormal vascularization and remodeling compared with isolated IA injections. BMAC showed superior pain relief in the synovium/IFP and subchondral bone compared with PRP. Further research is needed to optimize PRP and BMAC components for enhanced efficacy in OA management.

CLINICAL RELEVANCE

Our findings contribute to advancing the understanding of pain relief mechanisms and support the endorsement of IO injection of orthobiologics for the treatment of OA and joint pain.

Office-Based Intraosseous Infiltrations of PRGF as an Effective Treatment for Knee Osteoarthritis: A Retrospective Observational Clinical Study

The aim of this study was to explore and assess office-based ultrasound-guided intraosseous and intra-articular infiltrations of plasma rich in growth factors (PRGF) in patients with moderate and severe knee osteoarthritis (KOA). Seventy-nine patients (30 women and 49 men) with grade 3-4 KOA according to the Kellgren-Lawrence classification participated in the study. All patients were treated with a minimally invasive technique using local anesthesia WALANT (wide-awake local anesthesia no tourniquet) in the ambulatory setting. A PRGF intra-articular infiltration and two intraosseous infiltrations in the tibial plateau and femoral condyle were performed weekly for a total of three sessions. The evaluation of the results was carried out using knee injury and osteoarthritis outcome score (KOOS) at baseline and post-treatment. After a follow-up period of 11 months (median) [interquartile range, 7-14], all the KOOS domains showed statistically significant improvement (p < 0.001). Moreover, 88% of the patients showed a pain reduction of at least 10 points (minimally clinically important improvement) from pre- to post-treatment. Our retrospective study using the in-office procedure of ultrasound-guided combination of intra-articular and intraosseous infiltrations of PRGF is a safe and efficacious approach for the treatment of grade 3-4 knee osteoarthritis.

Efficacy and safety of platelet-rich plasma injections for the treatment of osteoarthritis: a systematic review and meta-analysis of randomized controlled trials

Background

In recent years, platelet-rich plasma (PRP) injections for osteoarthritis (OA) have been widely promoted in clinical practice, but their effectiveness is controversial. Therefore, we conducted a meta-analysis of relevant randomized controlled trials (RCTs) to determine the efficacy and safety of PRP injections for the treatment of OA.

Methods

We searched databases including Embase, Web of Science, Medline, PubMed, and the Cochrane Library for relevant studies. Two researchers (YQX and CG) performed literature screening, baseline data extraction, literature quality assessment, and heterogeneity analysis of RCTs from the retrieved studies. Based on the magnitude of heterogeneity I², random-effects or fixed-effects models were selected for the meta-analysis.

Results

We included 24 RCTs comprising 1344 patients with OA who met the inclusion criteria, with the main types of morbidity being knee osteoarthritis (KOA), hip osteoarthritis (HOA), ankle osteoarthritis (AOA), and temporomandibular joint osteoarthritis (TMJOA). Our results indicate that PRP injections were effective in improving Visual Analog Scale (VAS) pain scores in patients with KOA, HOA, and AOA compared to controls (AOA, MD = -1.15, CI = 95% [-1.74, -0.56], I² = 40%, P < 0.05; KOA, MD = -1.03, CI = 95% [-1.16, -0.9], I² = 87%, P < 0.05; TMJOA, MD = -1.35, CI = 95% [-1.74, -0.97], I² = 92%, P < 0.05) but showed no significant efficacy in patients with HOA (MD = -0.27, CI = 95% [-0.8, 0.26], I² = 56%, P>0.05). Compared to controls, PRP injections were effective in improving Knee Injury and Osteoarthritis Outcome Score (KOOS), including the patient's pain symptoms, activities of daily living (ADL), and adhesion symptomatology, but not for that of sports function (KOOS-pain, MD = 2.77, CI = 95% [0, 5.53], I² = 0%, P < 0.05; KOOS-symptoms, MD = 3.73, CI = 95% [0.76, 6.71], I² = 0%, P < 0.05; KOOS-ADL, MD = 3.61, CI = 95% [0.79, 6.43], I² = 0%, P < 0.05; KOOS-QOL, MD = 4.66, CI = 95% [0.98, 8.35], I² = 29%, P < 0.05, KOOS-sport, MD = 0.48, CI = 95% [-3.02, 3.98], I² = 0%, P > 0.05). PRP injections were effective in improving Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores, including pain, stiffness, and functional joint motion, in patients with OA compared with the control group (WOMAC-pain, MD = -1.08, CI = 95% [-1.62, -0.53], I² = 87%, P < 0.05; WOMAC-stiffness, MD = -1.17, CI = 88% [-1.72, -0.63], I² = 87%, P < 0.05; WOMAC-function, MD = -1.12, CI = 95% [-1.65, -0.58], I² = 87%, P < 0.05). In addition, subgroup analysis showed that leukocyte-poor (LP) PRP injections were more effective than leukocyte-rich (LR) PRP injections in improving pain symptoms in patients with OA (VAS, LR-PRP, MD = -0.81, CI = 95% [-1.65, -0.03], I² = 83%, P = 0.06 > 0.05; LP-PRP, MD = -1.62, CI = 95% [-2.36, -0.88], I² = 92%, P < 0.05). A subgroup analysis based on injection sites showed that no statistical difference in efficacy between intra-articular (IA) combined with intra-osseous (IO) simultaneous PRP injections. IA PRP injections only improved VAS pain scores in patients with OA (IA+IO PRP injections, MD = -0.74, CI =95% [-1.29, -0.18], I² = 61%, P < 0.05; IA PRP injections, MD = -1.43, CI = 95% [-2.18, -0.68], I² = 87%, P < 0.05, test for subgroup differences, P > 0.05, I² = 52.7%).

Conclusion

PRP injection therapy can safely and effectively improve functional activity in patients with OA and produce positive analgesic effects in patients with KOA, TMJOA, and AOA. However, PRP injection therapy did not significantly reduce pain symptoms in patients with HOA. In addition, the analgesic effect of LP-PRP was greater than that of LR-PRP.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022362066.

Intra-osseous plasma rich in growth factors enhances cartilage and subchondral bone regeneration in rabbits with acute full thickness chondral defects: Histological assessment

Background

Intra-articular (IA) combined with intra-osseous (IO) infiltration of plasma rich in growth factors (PRGF) have been proposed as an alternative approach to treat patients with severe osteoarthritis (OA) and subchondral bone damage. The aim of the study is to evaluate the efficacy of IO injections of PRGF to treat acute full depth chondral lesion in a rabbit model by using two histological validated scales (OARSI and ICRS II).

Methodology

A total of 40 rabbits were included in the study. A full depth chondral defect was created in the medial femoral condyle and then animals were divided into 2 groups depending on the IO treatment injected on surgery day: control group (IA injection of PRGF and IO injection of saline) and treatment group (IA combined with IO injection of PRGF). Animals were euthanized 56 and 84 days after surgery and the condyles were processed for posterior histological evaluation.

Results

Better scores were obtained in treatment group in both scoring systems at 56- and 84-days follow-up than in control group. Additionally, longer-term histological benefits have been obtained in the treatment group.

Conclusions

The results suggests that IO infiltration of PRGF enhances cartilage and subchondral bone healing more than the IA-only PRGF infiltration and provides longer-lasting beneficial effects.

Intra-osseous infiltration of adipose mesenchymal stromal cells and plasma rich in growth factors to treat acute full depth cartilage defects in a rabbit model: Serum osteoarthritis biomarkers and macroscopical assessment

Introduction

Intra-articular infiltration of plasma rich in growth factors (PRGF) and adipose mesenchymal stromal cells (AMSCs) are known to inhibit osteoarthritis progression. However, in severely affected patients, the treatment cannot reach the deeper layers of the articular cartilage; thus, its potential is limited. To overcome this limitation, intra-osseous infiltrations have been suggested. The purpose of this study is to assess the impact of intra-osseous infiltration therapies on serum biomarkers of osteoarthritis and to assess cartilage regeneration macroscopically.

Materials and methods

A total of 80 rabbits were divided into four groups based on the intra-osseous treatment administered on the day of surgery: control, PRGF, AMSCs and a combination of PRGF + AMSCs. In addition, all groups received a single intra-articular administration of PRGF on the same day. Serum biomarker levels were measured before infiltration and 28-, 56-, and 84-days post infiltration, and macroscopical assessment was conducted at 56- and 84-days follow-up post infiltration.

Results

In the PRGF + AMSCs group, significantly lower concentrations of hyaluronic acid and type II collagen cleavage neoepitope were recorded at all time points during the study, followed by PRGF, AMSCs and control groups. Regarding macroscopical assessment, lower scores were obtained in PRGF + AMSCs group at all study times.

Discussion

The results suggest that the combination of intra-articular PRGF with intra-osseous PRGF or AMSCs achieves better results in rabbits with acute chondral defects and that intra-osseous infiltration is a safe procedure.

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.

Office-Based Intraosseous Infiltrations of PRGF in Knee Osteoarthritis: Description of Technique

Knee osteoarthritis is a low-degree inflammatory condition that involves the whole synovial joint tissues as an organ. Recently, a biological approach using plasma rich in growth factors (PRGF) to tackle not only the synovial joint with intraarticular injections of PRGF, but also the subchondral bone with intraosseous infiltrations has been implemented with promising results. However, this procedure requires sedation, which limits the implementation of the procedure to operating room. We propose a modified and less cumbersome PRGF intraosseous infiltration approach for moderate and severe knee osteoarthritis, conducting the procedure in the ambulatory setting assisted with WALANT (wide-awake local anesthesia no tourniquet) technique. The proposed technique with a minimally invasive local anesthesia involves subcutaneous infiltration of lidocaine and epinephrine in a solution without sedation, and using ultrasound guidance, thereby streamlining the original procedure. This procedure is both a cost-effective and safe approach that may contribute to the widespread use of intraosseous infiltrations.

Treating Full Depth Cartilage Defects with Intraosseous Infiltration of Plasma Rich in Growth Factors: An Experimental Study in Rabbits

OBJECTIVE

Intraarticular (IA) administration of platelet-rich plasma (PRP) has been proposed as a new strategy to halt osteoarthritis (OA) progression. In patients with severe OA, its potential is limited because it is unable to reach the subchondral bone, so a new strategy is needed, and intraosseous (IO) infiltration has been suggested. The purpose is to assess the impact of IA together with IO infiltration of plasma rich in growth factors (PRGF) in serum hyaluronic acid (HA) and type II collagen cleavage neoepitope (C2C) levels.

DESIGN

A total of 32 rabbits were included in the study and randomly divided into 2 groups: control and treatment. A 4-mm chondral defect was created in the medial femoral condyle and IA followed by IO infiltration were performed. Serum C2C and HA levels were measured using enzyme-linked immunosorbent assay (ELISA) tests before infiltration and 28, 56, and 84 days post-infiltration.

RESULTS

Significant lower C2C serum levels were obtained in treatment group (IA + IO infiltration of PRGF) at 84 days post-infiltration than in control group (IA infiltration of PRGF + IO infiltration of saline solution), while no significant differences between groups were reported at any other study times. Regarding HA, at 56 days post-infiltration, greater significant levels were seen in the treatment group. However, at 84 days post-infiltration, no significant differences were obtained, although lower levels were reported in the treatment group.

CONCLUSIONS

Despite inconclusive, the results suggest that the combination of IA and IO infiltration with PRGF may enhance cartilage and subchondral bone regeneration, but further studies are needed.

Intraosseous Injections Are Safe And Effective in Knee Osteoarthritis: A Systematic Review

PURPOSE

To evaluate clinical outcomes after intraosseous injection for knee osteoarthritis systematically with available clinical evidence.

METHODS

A systematic search methodology of the PUBMED, EMBASE, and CINAHL databases was conducted in November 2020. The search workflow was in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The following inclusion criteria were adopted: clinical trials of any level of evidence, reporting clinical outcomes following intraosseous injections of bone substitutes or biologic agents, and mesenchymal stem cells or platelet-rich plasma into the knee as treatment modalities for osteoarthritis. Duplicate data and articles not written in English were excluded from this review.

RESULTS

Six studies were identified and included in this review, with a total of 167 patients. Two studies used subchondroplasty CaP injections, while 4 studies used intraosseous injections of platelet-rich plasma. Two studies provided Level II evidence, 2 studies provided Level III evidence, and a further 2 provided Level IV evidence. Five out of 6 studies reported data using the visual analog scale, 4 studies used the Knee Injury and Osteoarthritis Outcome Score, while 3 studies used the Western Ontario and McMaster Universities Osteoarthritis Index. Clinical improvements in pain and functionality were documented in all trials, with only a few patients experiencing adverse events.

CONCLUSION

Intraosseous injections for knee osteoarthritis are safe and effective. However, multiple pertinent variables such as safety, cost of treatment, and performance against placebos and other treatment modalities require further evaluation before intraosseous injections can be considered as standard treatment for patients presenting with osteoarthritis of the knee.

Role of Scaffolds, Subchondral, Intra-Articular Injections of Fresh Autologous Bone Marrow Concentrate Regenerative Cells in Treating Human Knee Cartilage Lesions: Different Approaches and Different Results

The value of bone marrow aspirate concentrates for treatment of human knee cartilage lesions is unclear. Most of the studies were performed with intra-articular injections. However, subchondral bone plays an important role in the progression of osteoarthritis. We investigated by a literature review whether joint, subchondral bone, or/and scaffolds implantation of fresh autologous bone marrow aspirate concentrated (BMAC) containing mesenchymal stem cells (MSCs) would improve osteoarthritis (OA). There is in vivo evidence that suggests that all these different approaches (intra-articular injections, subchondral implantation, scaffolds loaded with BMAC) can improve the patient. This review analyzes the evidence for each different approach to treat OA. We found that the use of intra-articular injections resulted in a significant relief of pain symptoms in the short term and was maintained in 12 months. However, the clinical trials indicate that the application of autologous bone marrow concentrates in combination with scaffolds or in injection in the subchondral bone was superior to intra-articular injection for long-term results. The tendency of MSCs to differentiate into fibrocartilage affecting the outcome was a common issue faced by all the studies when biopsies were performed, except for scaffolds implantation in which some hyaline cartilage was found. The review suggests also that both implantation of subchondral BMAC and scaffolds loaded with BMAC could reduce the need for further surgery.

Bone marrow concentrate injections for the treatment of osteoarthritis: evidence from preclinical findings to the clinical application

Purpose

To investigate the available literature on the use of bone marrow aspirate concentrate (BMAC) and summarize the current evidence supporting its potential for the injective treatment of joints affected by osteoarthritis (OA).

Methods

A systematic literature search was conducted on three electronic databases (PubMed, Embase, and Cochrane Library) in April 2020, using the following string: “((bone marrow concentrate) OR (BMC) OR (bone marrow aspirate concentrate) OR (BMAC)) AND (osteoarthritis)”, and inclusion criteria: clinical and preclinical (animal) studies of any level of evidence, written in English language, and evaluating the intra-articular or subchondral use of BMAC for the injective treatment of OA joints.

Results

The publication trend remarkably increased over time. A total of 22 studies were included in the qualitative data synthesis: four preclinical studies and 18 clinical studies, for a total number of 4626 patients. Safety was documented by all studies, with a low number of adverse events. An overall improvement in pain and function was documented in most of the studies, but the clinical studies present significant heterogeneity, few patients, short-term follow-up, and overall poor methodology.

Conclusion

There is a growing interest in the field of BMAC injections for the treatment of OA, with promising results in preclinical and clinical studies in terms of safety and effectiveness. Nevertheless, the current knowledge is still preliminary. Preclinical research is still needed to optimize BMAC use, as well as high-level large controlled trials to better understand the real potential of BMAC injections for the treatment of patients affected by OA.

Meta-analysis Comparing Platelet-Rich Plasma vs Hyaluronic Acid Injection in Patients with Knee Osteoarthritis

PURPOSE

The purpose of this meta-analysis was to compare platelet-rich plasma (PRP) and hyaluronic acid (HA) in patients with knee osteoarthritis (KOA).

METHODS

Randomized controlled trials (RCTs) comparing the use of PRP and HA in KOA patients were retrieved from each database from the establishment date to April 2018. Outcome measurements were the Western Ontario and McMaster Universities Arthritis Index (WOMAC), visual analog scale (VAS), International Knee Documentation Committee, and Lequesne Index scores and adverse events. The pooled data were evaluated with Review Manager 5.3.5.

RESULTS

Fifteen RCTs (N = 1,314) were included in our meta-analysis. The present meta-analysis indicated that PRP injections reduced pain more effectively than HA injections in patients with KOA at six and 12 months of follow-up, as evaluated by the WOMAC pain score; the VAS pain score showed a significant difference at 12 months. Moreover, better functional improvement was observed in the PRP group, as demonstrated by the WOMAC function score at three, six, and 12 months. Additionally, PRP injections did not display different adverse event rates compared with HA injections.

CONCLUSION

In terms of long-term pain relief and functional improvement, PRP injections might be more effective than HA injections as a treatment for KOA. The optimal dosage, the timing interval and frequency of injections, and the ideal treatment for different stages of KOA remain areas of concern for future investigations.

Platelet-rich plasma injections delay the need for knee arthroplasty: a retrospective study and survival analysis

PURPOSE

The biological action of platelet-rich plasma (PRP) could slow down the osteoarthritis progression, resulting in a delay of joint replacement. This work aims to evaluate the ability of PRP to postpone and even avoid knee replacement in patients with knee osteoarthritis (KOA) analyzing, on the one hand, the time of delay and on the other hand the percentage of patients without undergoing total knee arthroplasty (TKA).

METHODS

A retrospective analysis and a survival analysis were conducted. KOA patients who underwent knee replacement between 2014 and 2019 and previously received PRP infiltrations were included in the retrospective analysis. Regarding survival analysis, KOA patients who received PRP treatment during 2014 and with follow-up until 2019 were included. The dates of PRP treatment and TKA, KOA severity, age of the patients, number of PRP cycles, and administration route were analyzed.

RESULTS

This work included 1084 patients of which 667 met the inclusion criteria. 74.1% of the patients in the retrospective study achieved a delay in the TKA of more than 1.5 years, with a median delay of 5.3 years. The survival analysis showed that 85.7% of the patients did not undergo TKA during the five year follow-up. The severity degree, age, PRP cycles, and administration route had a statistically significant influence on the efficacy of PRP in delaying surgery.

CONCLUSION

These data suggest that the application of PRP in KOA patients is a treatment that could delay TKA, although further studies are needed to understand and improve this therapy.

Optimising proliferation and migration of mesenchymal stem cells using platelet products: A rational approach to bone regeneration

This study investigates how mesenchymal stem cell's (MSCs) proliferation and migration abilities are influenced by various platelet products (PP). Donor-matched, clinical-, and control laboratory-standard PPs were generated and assessed based on their platelet and leukocyte concentrations. Bone marrow derived MSCs were exposed to these PP to quantify their effect on in vitro MSC proliferation and migration. An adapted colony forming unit fibroblast (CFU-F) assay was carried out on bone marrow aspirate using clinical-standard PP-loaded electrospun poly(ϵ-caprolactone) (PCL) membrane to mimic future clinical applications to contain bone defects. Clinical-standard PP had lower platelet (2.5 fold, p < 0.0001) and higher leukocyte (14.1 fold, p < 0.0001) concentrations compared to laboratory-standard PP. It induced suboptimal MSC proliferation compared to laboratory-standard PP and fetal calf serum (FCS). All PP induced significantly more MSC migration than FCS up to 24 h. The removal of leukocytes from PP had no effect on MSC proliferation or migration. The PP-loaded membranes successfully supported MSC colony formation. This study indicates that platelet concentrations in PP impact MSC proliferation more than the presence of leukocytes, whilst MSC migration in response to PP is not influenced by platelet or leukocyte numbers. Clinical-standard PP could be applied alongside manufactured membranes in the future treatment of bone reconstruction. © 2019 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 37:1329-1338, 2019.

Treating Severe Knee Osteoarthritis with Combination of Intra-Osseous and Intra-Articular Infiltrations of Platelet-Rich Plasma: An Observational Study

OBJECTIVE

Assessing the therapeutic effects of a combination of intra-articular and intra-osseous infiltrations of platelet-rich plasma (PRP) to treat severe knee osteoarthritis (KOA) using intra-articular injections of PRP as the control group.

DESIGN

In this observational study, 60 patients suffering from severe KOA were treated with intra-articular infiltrations of PRP (IA group) or with a combination of intra-osseous and intra-articular infiltrations of PRP (IO group). Both groups were matched for sex, age, body mass index, and radiographic severity (III and IV degree according to Ahlbäck scale). Clinical outcome was evaluated at 2, 6, and 12 months, using the Knee injury and Osteoarthritis Outcome Score (KOOS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaires.

RESULTS

At 2, 6 and 12 months after treatment, IO group had a significant improvement in all KOOS and WOMAC subscales ( P < 0.05). On the contrary, patients of the IA group did not improve in any of the scores. Sixteen out of 30 IO group patients showed minimal clinically important improvement (MCII) whereas 8 out of 30 IA group patients showed this response at 6 months (26.7%; 95% CI -0.4 to 49.9; P = 0.037). At 12 months, 14 patients of IO group and 5 patients of the IA group showed MCII (30%; 95% CI 4.3 to 51.9; P = 0.013). No differences between groups were observed at 2 months.

CONCLUSIONS

PRP intra-articular injections in severe KOA were not effective and did not provide any benefit. Combination of intra-articular and intra-osseous infiltrations of PRP was not clinically superior at 2 months, but it showed superior clinical outcomes at 6 and 12 months when compared with intra-articular injections of PRP.

Current concepts in intraosseous Platelet-Rich Plasma injections for knee osteoarthritis

Knee osteoarthritis (OA) is a degenerative process that slowly destroys the joints producing pain and loss of function, and diminishes the quality of life. Current treatments alleviate this symptomatology but do not stop the disease, being total knee arthroplasty the only definitive solution. Among the emerging treatments, Platelet-Rich Plasma (PRP) has shown promising results in the treatment of OA. However, to improve its effectiveness, it is necessary to approach this pathology targeting the whole joint, not only the cartilage, but including other tissues such as subchondral bone. The pathological processes that occur in the subchondral bone have influence of the cartilage loss, aggravating the disease. The combination of intraarticular infiltrations with intraosseous infiltrations regulates the biological processes of the tissues, reducing the inflammatory environment and modulating the overexpression of biomolecules that generate an aberrant cellular behavior. Although the first clinical results using this technique are promising, further research and developing adequate protocols are necessary to achieve good clinical results.

Autologous fibrin scaffolds: When platelet- and plasma-derived biomolecules meet fibrin

The healing of vascularized mammalian tissue injuries initiate with hemostasis and clotting as part of biological defense system leading to the formation of a fibrin clot in which activated platelets are trapped to quickly stop bleeding and destroy microbials. In order to harness the therapeutic potential of biomolecules secreted by platelets and stemmed from plasma, blood deconstruction has allowed to yield autologous platelet-and plasma-derived protein fibrin scaffold. The autologous growth factors and microparticles stemmed from platelets and plasma, interact with fibrin, extracellular matrix, and tissue cells in a combinatorial, synergistic, and multidirectional way on mechanisms governing tissue repair. This interplay will induce a wide range of cell specifications during inflammation and repair process including but not limited to fibrogenesis, angiogenesis, and immunomodulation. As biology-as-a-drug approach, autologous platelet-and plasma-derived protein fibrin scaffold is emerging as a safe and efficacious natural human-engineered growth factor delivery system to repair musculoskeletal tissues, and skin and corneal ulcers and burns. In doing so, it acts as therapeutic agent not perfect but close to biological precision. However, this autologous, biocompatible, biodegradable, and long in vivo lasting strategy faces several challenges, including its non-conventional single dose-response effect, the lack of standardization in its preparation and application, and the patient's biological features. In this review, we give an account of the main events of tissue repair. Then, we describe the procedure to prepare autologous platelet-and plasma-derived protein fibrin scaffolds, and the rationale behind these biomaterials, and finally, we highlight the significance of strategic accuracy in their application.

Comparison of platelet-rich plasma vs hyaluronic acid injections in patients with knee osteoarthritis: A protocol for a systematic review and meta-analysis

BACKGROUND

Knee osteoarthritis (KOA) is a progressive joint disease involving intraarticular and periarticular structures. In recent years, there has been increasing interest in the use of autologous growth factors, such as intraarticular injections of platelet-rich plasma (PRP), to treat KOA. It is necessary to update the research and reevaluate the efficacy and safety of PRP to provide up-to-date evidence for KOA management. Therefore, we provide a protocol for a systematic review of PRP for KOA.

METHODS

The aim of this study was to retrieve papers on the topic of PRP treatment for KOA in electronic databases including PubMed, Embase, and the Cochrane Library. The search will include studies that were published from the time the databases were established until April 2018. The entire process will include study selection, data extraction, risk of bias assessment, and meta-analyses.

RESULTS

The literature will provide a high-quality analysis of the current evidence supporting PRP for KOA based on various comprehensive assessments including the Western Ontario and McMaster Universities Osteoarthritis Index, visual analog scale scores, International Knee Documentation Committee scores, Lequesne index scores, and adverse events.

CONCLUSION

This proposed systematic review will provide up-to-date evidence to assess the effect of PRP treatment for patients with KOA.

PROSPERO REGISTRATION NUMBER

CRD42018108825.

Platelet-rich plasma: myth or reality?

Platelet-rich plasma (PRP) is a preparation for therapeutic purposes that is increasingly accepted for various musculoskeletal disorders, due to its theoretical potential to repair tissues with poor healing capacity. Several randomised clinical trials have investigated the capacity of PRP to repair tendons, ligaments, muscles and cartilage, and to date there is level 1a evidence to support its use for lateral epicondylitis, osteoarthritis of the knee, plantar fasciitis and rotator cuff tendinopathy; and level 1b for patellar tendinopathy and osteoarthritis of the hip. Retrospective cohort studies and case series describe promising results with PRP for treating other musculoskeletal disorders. Since its side effects are fewer than those of the control groups, the treatment is considered practically harmless and is being increasingly used. Further randomised clinical trials are necessary to establish future indications, and to confirm effectiveness and safety.

Hyperacute serum has markedly better regenerative efficacy than platelet-rich plasma in a human bone oxygen-glucose deprivation model

AIM

Platelet-rich plasma (PRP) and hyperacute serum (HAS) were compared in a novel human model of ex vivo bone damage induced by oxygen-glucose deprivation (OGD).

MATERIALS & METHODS

Osteoarthritic subchondral bone pieces were harvested from discarded femoral heads during hip replacement surgery and subjected to transient OGD.

RESULTS

Proteome profiling revealed that PRP is more angiopoietic, whereas HAS is more antiangiopoietic in composition. However, treatment of OGD-exposed bone with multiple PRP preparations had no effect on cell counts, whereas HAS restored cell proliferation capacity and rescued viable cell number following OGD.

CONCLUSION

A similar pro-proliferation effect was observed with recombinant growth factors, indicating that HAS may be an alternative agent for enhancing the regeneration of damaged bone cells.

Comparison of hyaluronic acid and PRP intra-articular injection with combined intra-articular and intraosseous PRP injections to treat patients with knee osteoarthritis

The aim of this study was to evaluate the benefit provided by intraosseous infiltration combined with intra-articular injection of platelet-rich plasma to treat mild and moderate stages of knee joint degeneration (Kellgren-Lawrence score II-III) compared with other treatments, specifically intra-articular injection of PRP and of HA. Eighty-six patients with grade II to grade III knee OA according to the Kellgren-Lawrence classification were randomly assigned to intra-articular combined with intraosseous injection of PRP (group A), intra-articular PRP (group B), or intra-articular HA (group C). Patients in group A received intra-articular combined with intraosseous injection of PRP (administered twice, 2 weeks apart). Patients in group B received intra-articular injection of PRP every 14 days. Patients in group C received a series of five intra-articular injections of HA every 7 days. All patients were evaluated using the Visual Analogue Scale (VAS) and Western Ontario and McMaster Universities (WOMAC) score before the treatment and at 1, 3, 6, 12, and 18 months after treatment. There were significant improvements at the end of the 1st month. Notably, group A patients had significantly superior VAS and WOMAC scores than were observed in groups B and C. The VAS scores were similar in groups B and group C after the 6th month. Regarding the WOMAC scores, groups B and C differed at the 1st, 3rd, 6th, and 12th months; however, no significant difference was observed at the 18th month. The combination of intraosseous with intra-articular injections of PRP resulted in a significantly superior clinical outcome, with sustained lower VAS and WOMAC scores and improvement in quality of life within 18 months.

PRP in OA knee - update, current confusions and future options

Positive results have been uniformly observed by various researchers for platelet-rich plasma (PRP) in early osteoarthritis (OA) knee in the past few years. PRP has clearly demonstrated its supremacy in comparison to hyaluronic acid (HA) and placebo in various clinical trials and is undoubtedly the best option available for symptomatic treatment in early OA. The release of growth factors from PRP occurs immediately and lasts for around three weeks and the clinical effect tends to wane down by the end of the year. Prolonged and sustained release of growth factors from platelets could possibly help in much better biological healing and sustained clinical effects. PRP in combination with biocompatible carriers could be one way of achieving this. Gelatin hydrogel PRP and chitosan PRP seem to be promising based on early in vitro studies and animal studies. PRP in combination with hyaluronic acid also seems to be additive. This article intends to discuss the present status of the PRP, confusions surrounding its use, upcoming trends and ideas for improvising PRP for use early OA knees based on available evidence.

Modulation of Synovial Fluid-Derived Mesenchymal Stem Cells by Intra-Articular and Intraosseous Platelet Rich Plasma Administration

The aim of this study was to evaluate the effect of intra-articular (IA) or a combination of intra-articular and intraosseous (IO) infiltration of Platelet Rich Plasma (PRP) on the cellular content of synovial fluid (SF) of osteoarthritic patients. Thirty-one patients received a single infiltration of PRP either in the IA space (n = 14) or in the IA space together with two IO infiltrations, one in the medial femoral condyle and one in the tibial plateau (n = 17). SF was collected before and after one week of the infiltration. The presence in the SF of mesenchymal stem cells (MSCs), monocytes, and lymphocytes was determined and quantified by flow cytometry. The number and identity of the MSCs were further confirmed by colony-forming and differentiation assays. PRP infiltration into the subchondral bone (SB) and the IA space induced a reduction in the population of MSCs in the SF. This reduction in MSCs was further confirmed by colony-forming (CFU-F) assay. On the contrary, IA infiltration alone did not cause variations in any of the cellular populations by flow cytometry or CFU-F assay. The SF of osteoarthritic patients contains a population of MSCs that can be modulated by PRP infiltration of the SB compartment.

Combination of Intra-Articular and Intraosseous Injections of Platelet Rich Plasma for Severe Knee Osteoarthritis: A Pilot Study

The aim of this study was to assess a novel approach to treating severe knee osteoarthritis by targeting synovial membrane, superficial articular cartilage, synovial fluid, and subchondral bone by combining intra-articular injections and intraosseous infiltrations of platelet rich plasma. We explored a new strategy consisting of intraosseous infiltrations of platelet rich plasma into the subchondral bone in combination with the conventional intra-articular injection in order to tackle several knee joint tissues simultaneously. We assessed the clinical outcomes through osteoarthritis outcome score (KOOS) and the inflammatory response by quantifying mesenchymal stem cells in synovial fluid. There was a significant pain reduction in the KOOS from baseline (61.55 ± 14.11) to week 24 (74.60 ± 19.19), after treatment (p = 0.008), in the secondary outcomes (symptoms, p = 0.004; ADL, p = 0.022; sport/rec., p = 0.017; QOL, p = 0.012), as well as VAS score (p < 0.001) and Lequesne Index (p = 0.008). The presence of mesenchymal stem cells in synovial fluid and colony-forming cells one week after treatment decreased substantially from 7.98 ± 8.21 MSC/μL to 4.04 ± 5.36 MSC/μL (p = 0.019) and from 601.75 ± 312.30 to 139.19 ± 123.61  (p = 0.012), respectively. Intra-articular injections combined with intraosseous infiltrations of platelet rich plasma reduce pain and mesenchymal stem cells in synovial fluid, besides significantly improving knee joint function in patients with severe knee osteoarthritis. This trial is registered on EudraCT with the number 2013-003982-32.

A new strategy to tackle severe knee osteoarthritis: Combination of intra-articular and intraosseous injections of Platelet Rich Plasma

INTRODUCTION

Knee osteoarthritis (KOA) is a mechanically induced, cytokine and enzyme-mediated disorder involving all the joint tissue of the knee. Rebuilding a physiological-homeostatic network at the tissue level following knee organ failure, such as in severe KOA, is a daunting task with therapeutic targets encompassing the articular cartilage, synovium and subchondral bone. Intraarticular infiltration of plasma rich in growth factors (PRP) has emerged as a promising symptomatic approach, although it is insufficient to reach the subchondral bone.

AREAS COVERED

This review addresses current molecular and cellular data in joint homeostasis and osteoarthritis pathophysiology. In particular, it focuses on changes that subchondral bone undergoes in knee osteoarthritis and evaluates recent observations on the crosstalk among articular cartilage, subchondral bone and synovial membrane. In addition, we review some mechanistic aspects that have been proposed and provide the rationale for using PRP intraosseously in KOA.

EXPERT OPINION

The knee joint is a paradigm of autonomy and connectedness of its anatomical structures and tissues from which it is made. We propose an innovative approach to the treatment of severe knee osteoarthritis consisting of a combination of intraarticular and intraosseous infiltrations of PRP, which might offer a new therapeutic tool in KOA therapy.