The Use of Platelet-Rich Plasma in Symptomatic Knee Osteoarthritis

Potential therapeutic strategies for osteoarthritis via CRISPR/Cas9 mediated gene editing

Osteoarthritis (OA) is an incapacitating and one of the most common physically degenerative conditions with an assorted etiology and a highly complicated molecular mechanism that to date lacks an efficient treatment. The capacity to design biological networks and accurately modify existing genomic sites holds an apt potential for applications across medical and biotechnological sciences. One of these highly specific genomes editing technologies is the CRISPR/Cas9 mechanism, referred to as the clustered regularly interspaced short palindromic repeats, which is a defense mechanism constituted by CRISPR associated protein 9 (Cas9) directed by small non-coding RNAs (sncRNA) that bind to target DNA through Watson-Crick base pairing rules where subsequent repair of the target DNA is initiated. Up-to-date research has established the effectiveness of the CRISPR/Cas9 mechanism in targeting the genetic and epigenetic alterations in OA by suppressing or deleting gene expressions and eventually distributing distinctive anti-arthritic properties in both in vitro and in vivo osteoarthritic models. This review aims to epitomize the role of this high-throughput and multiplexed gene editing method as an analogous therapeutic strategy that could greatly facilitate the clinical development of OA-related treatments since it's reportedly an easy, minimally invasive technique, and a comparatively less painful method for osteoarthritic patients.

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.

Lumbar Transforaminal Injection of Steroids versus Platelet-Rich Plasma for Prolapse Lumbar Intervertebral Disc with Radiculopathy: A Randomized Double-Blind Controlled Pilot Study

STUDY DESIGN

Double-blind randomized controlled pilot study.

PURPOSE

The purpose of this study was to compare outcomes of steroids with autologous platelet-rich plasma (PRP) administered by lumbar transforaminal injection (LTI) in patients with lumbar radiculopathy.

OVERVIEW OF LITERATURE

Degenerative disc disease of the lumbar spine is one of the most common conditions managed by spine surgeons in routine practice. Once conservative management fails, LTI is diagnostic and often therapeutic. Steroids are the gold standard drug used for LTI but have limitations and side effects.

METHODS

In this single-center double-blind randomized controlled pilot study, 46 patients were recruited and randomized by the lottery method. The Visual Analog Scale (VAS) for leg pain, modified Oswestry Disability Index (mODI), and Short-Form 12 (SF-12) were assessed at 1 week, 3 weeks, 6 weeks, 6 months, and 1 year.

RESULTS

Both groups were comparable in terms of demographics, preprocedure VAS scores, mODI, and SF-12 scores (p=0.52). At the 1-week follow-up, the steroid group had significantly better improvement than the PRP group (p=0.0001). At the 3-week follow-up, both groups showed comparable outcomes; however, the PRP group had better symptom improvement. At 6 weeks and 6 months, the PRP group had better outcomes (VAS, p<0.0001; ODI, p=0.02; SF-12, p=0.002). Moreover, 17 and 16 patients in the steroid and PRP groups underwent repeat LTI with steroids or surgery because of pain recurrence during follow-up. At 1 year, no difference in outcomes was observed.

CONCLUSIONS

PRP may be a useful alternative to steroids for LTI in lumbar radiculopathy. Although improvement was delayed and 1-year outcomes were comparable, the 6-week and 6-month outcomes were better with PRP than with LTI. Multiple PRP injections may be beneficial because of its autologous nature. However, further studies with a larger number of participants, longer follow-up, and repeat LTIs are warranted to draw definite conclusions.

Ten years of injectable platelet-rich fibrin

The use of platelet-rich fibrin (PRF) has seen widespread advantages over platelet-rich plasma (PRP) in many fields of medicine. However, until 2014, PRF remained clinically available only in its solid clotted form. Modifications to centrifugation protocols and tube technology have led to the development of a liquid injectable version of PRF (i-PRF). This narrative review takes a look back at the technological developments made throughout the past decade and further elaborates on their future clinical applications. Topics covered include improvements in isolation techniques and protocols, ways to further concentrate i-PRF, and the clinical impact and relevance of cooling i-PRF. Next, various uses of i-PRF are discussed, including its use in regenerative periodontology, implantology, endodontics, temporomandibular joint injections, and orthodontic tooth movement. Furthermore, various indications in medicine are also covered, including its use in sports injuries and osteoarthritis of various joints, treatment of diabetic ulcers/wound care, and facial esthetics and hair regrowth. Finally, future applications are discussed, mainly its use as a drug delivery vehicle for small biomolecules, such as growth factors, antibiotics, exosomes, and other medications that may benefit from the controlled and gradual release of biomolecules over time.

Platelet-rich plasma for pilonidal disease: a systematic review

OBJECTIVE

To examine the use of platelet-rich plasma (PRP) for treatment of pilonidal disease (PD) and thus provide a reference for clinical application.

METHODS

A systematic review of PubMed and the Cochrane Library was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We considered all studies that reported the use of PRP for treatment of PD. Extracted data included the first author's name, year of publication, study type, number of included patients, inclusion and exclusion criteria, interventions, anesthesia, application of PRP (source, preparation, dose, and operation), antibiotics, follow-up time, therapeutic outcomes, and adverse events.

RESULTS

In total, eight randomized controlled trials and one prospective cohort study involving 809 patients were included. PRP reduced pain, accelerated healing, and reduced adverse events. The application of combined minimally invasive surgery achieved better results. However, overfilling of the wound with PRP in minimally invasive surgeries was shown to potentially increase the risk of adverse events.

CONCLUSION

PRP can be used as an adjuvant treatment in PD surgery to improve the therapeutic effect and reduce adverse events. The optimal combination of PRP and various factors is an important direction of future research.INPLASY registration number: INPLASY2023100070.

Interventional Techniques for the Management of Knee Osteoarthritis: A Literature Review

Osteoarthritis of the knee is a prevalent condition that causes pain, discomfort, and disability that can severely impact the quality of life. This literature review aims to review the various interventional pain management techniques available to treat knee osteoarthritis. It analyzes the efficacy of various interventions such as intra-articular corticosteroids, prolotherapy, viscosupplementation, platelet-rich plasma, and genicular nerve blocks with radiofrequency ablation or cryoneurolysis. We searched databases for studies published in the past 20 years. A total of 37 articles were included. The literature supports the idea that a comprehensive treatment plan consisting of the various aforementioned techniques can provide relief for patients while delaying or avoiding joint replacement surgery.

Expanding applications of allogeneic platelets, platelet lysates, and platelet extracellular vesicles in cell therapy, regenerative medicine, and targeted drug delivery

Platelets are small anucleated blood cells primarily known for their vital hemostatic role. Allogeneic platelet concentrates (PCs) collected from healthy donors are an essential cellular product transfused by hospitals to control or prevent bleeding in patients affected by thrombocytopenia or platelet dysfunctions. Platelets fulfill additional essential functions in innate and adaptive immunity and inflammation, as well as in wound-healing and tissue-repair mechanisms. Platelets contain mitochondria, lysosomes, dense granules, and alpha-granules, which collectively are a remarkable reservoir of multiple trophic factors, enzymes, and signaling molecules. In addition, platelets are prone to release in the blood circulation a unique set of extracellular vesicles (p-EVs), which carry a rich biomolecular cargo influential in cell-cell communications. The exceptional functional roles played by platelets and p-EVs explain the recent interest in exploring the use of allogeneic PCs as source material to develop new biotherapies that could address needs in cell therapy, regenerative medicine, and targeted drug delivery. Pooled human platelet lysates (HPLs) can be produced from allogeneic PCs that have reached their expiration date and are no longer suitable for transfusion but remain valuable source materials for other applications. These HPLs can substitute for fetal bovine serum as a clinical grade xeno-free supplement of growth media used in the in vitro expansion of human cells for transplantation purposes. The use of expired allogeneic platelet concentrates has opened the way for small-pool or large-pool allogeneic HPLs and HPL-derived p-EVs as biotherapy for ocular surface disorders, wound care and, potentially, neurodegenerative diseases, osteoarthritis, and others. Additionally, allogeneic platelets are now seen as a readily available source of cells and EVs that can be exploited for targeted drug delivery vehicles. This article aims to offer an in-depth update on emerging translational applications of allogeneic platelet biotherapies while also highlighting their advantages and limitations as a clinical modality in regenerative medicine and cell therapies.

Platelet-rich plasma alleviates knee arthritis in rats by inhibiting p65

Knee osteoarthritis (KOA) is a chronic joint disease characterized by the degeneration of articular cartilage. In this study, we explored the potential therapeutic effects of platelet-rich plasma (PRP) and identified molecular targets for treating KOA. A rat model of KOA was established via the Hulth method and primary knee joint chondrocytes were isolated to evaluate the effects of PRP and shRNA targeting p65 (sh-p65). ELISA was used to detect inflammatory factors, including IL-6, IL-1β, and TNF-α. HE staining, Safranin O/Fast Green staining and Masson staining were performed to evaluate the morphology of articular cartilage, followed by detection of p65, COL2A1, ACAN, MMP13, and ADAMTS5 expression. The proliferation and apoptosis of primary knee chondrocytes were detected by the CCK-8 assay and TUNEL staining, respectively. Treatment with either PRP or sh-p65 decreased IL-6, IL-1β, and TNF-α levels in the peripheral blood of KOA rats and chondrocyte culture supernatants, increased COL2A1 and ACAN levels, and decreased MMP13 and ADAMTS5 expression. Furthermore, administration of PRP or sh-p65 exerted protective effects on articular cartilage, enhanced the vitality of knee joint chondrocytes, and inhibited apoptosis. Collectively, PRP inhibited inflammation, promoted chondrocyte proliferation and cartilage matrix secretion, and induced cartilage regeneration by suppressing p65 expression; these effects allow PRP to alleviate KOA progression. P65-based targeted therapy administered in combination with PRP might be a promising strategy for treating KOA.

The Invasive Management of Pain: Diagnosis and New Treatment Options

Both the diagnosis and treatment of pain are evolving, especially in interventional approaches. Diagnosis of low back pain combines old and new methodologies, in particular, it involves an expanded role for ultrasound. While low back pain is a common complaint, there are many etiologies to the condition which must be explored before a final diagnosis can be made and treatment planned. Tumors and infections are rarely involved in low back pain but should be ruled out in the initial phase itself since failing to address them early can have devastating consequences. Some invasive treatments seem promising in the management of low back pain. Treating musculoskeletal pain with regenerative medicine, such as platelet-rich plasma, holds great promise. Autologous blood products are safe and may help stimulate the body's own responses for regeneration. The so-called "orthobiologics" play a role in sports medicine and the treatment of musculoskeletal pain. Neuromodulation, especially spinal cord stimulation, is undergoing a renaissance with new waveforms, devices, and a greater albeit incomplete understanding of its mechanisms of action. Spinal cord stimulation is not a first-line therapy and not all patients or all back problems respond to this treatment. Nevertheless, the therapy can be safe, effective, and cost-effective with appropriate patient selection. Radiofrequency ablation of nerves in the form of neurotomy can be effective in reducing the pain of osteoarthritis. These procedures, including the newer cooled radiofrequency neurotomy, can restore function, reduce pain, and may potentially have an opioid-sparing effect. Technical expertise in nerve and anatomy is needed for the use of this technique. This review article aims to provide updated information on some invasive intervention techniques in pain management.

The Epidemiology of Platelet-Rich Plasma Injections From 2010 to 2020 in a Large US Commercial Insurance Claims Database: A Recent Update

INTRODUCTION

The popularity of platelet-rich plasma (PRP) injections for the treatment of orthopaedic conditions has grown markedly. We sought to better define the trends in the usage of orthopaedic PRP injections across an insured US population over the past decade.

METHODS

The PearlDiver M91Ortho commercial administrative claims database was queried for all patients receiving PRP injections for orthopaedic conditions from 2010 through the first quarter of 2020 (Q1.2020). Trends in PRP use, reimbursement charges, demographics, joints injected, and administering physicians were assessed over time and reported as year-over-year (YOY) changes.

RESULTS

Over the study period, 14,096 unique patients had 17,759 orthopaedic PRP injections. The number of PRP injections administered had a YOY increase of 7.1% (144 injections/year, 95% confidence interval [CI] = 89 to 199, Ptrend = 0.0009). A YOY increase of 895% was observed in total nonsurgical charges ($683,974/yr, 95% CI 441,504 to 926,444, Ptrend = 0.0009). The median age of PRP recipients increased (YOY change = +0.6 years, 95% CI 0.4 to 0.8, Ptrend = 0.0005). Injections to the elbow (YOY change = -0.8%, 95% CI -0.10% to [-0.06%], Ptrend = 0.005) and foot/ankle (YOY change = -1.0%, 95% CI -1.4% to [-0.06%], Ptrend = 0.002) decreased, whereas hip (YOY change = +0.4%, 95% CI 0.2% to 0.6%, Ptrend = 0.019), knee (YOY change = +0.9%, 95% CI 0.3% to 1.2%, Ptrend = 0.016), and spine (YOY change = +0.2%, 95% CI 0.0% to 0.4%, Ptrend = 0.033) injections increased. PRP injections given by sports medicine orthopaedic surgeons (YOY change = +0.8%, 95% CI 0.6% to 1.2%, Ptrend <0.0001) increased over time, whereas those by general orthopaedic surgeons decreased (YOY change = -0.9, 95% CI -1.2 to [-0.6%], Ptrend = 0.001).

CONCLUSION

PRP injections quadrupled in prevalence from 2010 to Q1.2020, with a projected increase in annual usage in this data set of 66% by 2030. As greater evidence-based indications for PRP use are identified, more specialists and insurance providers may consider expanding their involvement in this growing field.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Research trends of platelet-rich plasma therapy on knee osteoarthritis from 2011 to 2021: A review

BACKGROUND

Platelet-rich plasma (PRP) has been widely used to alleviate osteoarthritis of the knee, and research results are abundant. However, there are no bibliometric reports in publications in this field. Therefore, the current status of PRP for the treatment of osteoarthritis of the knee from 2011 to 2021 was analyzed using Citespace 6.1.R2 software.

METHODS

Publications regarding PRP treating Knee Osteoarthritis between 2011 and 2021 were extracted from the Web of Science database. CiteSpace was used to analyze the number of publications, countries, institutions, journals, authors, cited references, and keywords by using standard bibliometric indicators.

RESULTS

A total of 988 publications were searched from 2011 to 2021. In the last decade, the number of publications has increased in the field. Brian J. Cole was the author with the most output, with 31 relevant articles, and Giuseppe Filardo ranked first in cited authors. Am J Sport Med was the most cited journal. In this field, the most prolific country is the United States and the most prolific institution is Rush University. An article published by Sandeep Patel ranked first in cited references with 118 citations. "Randomized controlled trial" was the most bursting keyword and other more popular keywords about PRP for knee osteoarthritis: "hyaluronic acid," "double-blind," and "mesenchymal stem cell."

CONCLUSION

This bibliometric study provides a decade of current clinical research on PRP for the treatment of osteoarthritis of the knee, which can help researchers understand the hot spots in the field and provide a new direction for their research.

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.

Platelet Rich Plasma in the Repair of Articular Cartilage Injury: A Narrative Review

OBJECTIVE

This paper reviews the research of platelet-rich plasma (PRP) in articular cartilage injury repair, to assess the mechanism, utilization, and efficacy of PRP in the treatment of articular cartilage injury, hoping to provide a theoretical basis for the clinical application of PRP in the future.

MATERIALS AND METHODS

A comprehensive database search on PRP applications in cartilage repair was performed. Among them, the retrieval time range of PRP in clinical trials of repairing knee cartilage injury was from January 1, 2021 to January 1, 2022. Non-clinical trials and studies unrelated to cartilage injury were excluded.

RESULT

PRP can affect inflammation, angiogenesis, cartilage protection, and cellular proliferation and differentiation after articular cartilage injury through different pathways. In all, 13 clinical trials were included in the analysis.

CONCLUSION

PRP is an emergent therapeutic approach in tissue engineering. Most studies reported that PRP has a positive effect on cartilage injury, improving the joint function, meanwhile there is a lack of standardized standards. The technology of PRP in the repair and treatment of articular cartilage injury is worthy of further research.

Therapeutic Efficacy and Mid-Term Durability of Urethral Sphincter Platelet-Rich Plasma Injections to Treat Postprostatectomy Stress Urinary Incontinence

Platelet-rich plasma (PRP) is used for tissue repair and regeneration. Herein, we investigated the therapeutic efficacy and mid-term durability of injections of PRP into the urethral sphincter for the management of postprostatectomy incontinence (PPI). Thirty-nine patients with PPI that were refractory to conservative treatments were prospectively enrolled. They received repeated PRP urethral sphincter injections monthly for a total of four months. The primary endpoint was the Global Response Assessment (GRA) score after treatment. The secondary endpoints included changes in the stress urinary incontinence (SUI) visual analog scale (VAS) from baseline to the end of follow-up and urodynamic parameters from baseline to 3 months. The mean follow-up period after the entire treatment course was 21.0 ± 11.3 (range: 1.6−36.3) months. After PRP injections, the median GRA score with quartiles was 2.0 (1.0, 2.0). The SUI VAS and abdominal leak point pressure significantly improved from 6.9 ± 1.8 to 4.4 ± 2.3, p < 0.001, and from 74.8 ± 37.0 to 115.5 ± 57.9 cmH2O, p = 0.004, respectively, after the fourth PRP urethral sphincter injection. Following PRP urethral sphincter injections, the severity of SUI significantly reduced, indicating efficacy and mid-term durability as a novel treatment for PPI.

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.

Does Bone Marrow Edema Influence the Clinical Results of Intra-Articular Platelet-Rich Plasma Injections for Knee Osteoarthritis?

Platelet-rich plasma (PRP) is increasingly used for the intra-articular treatment of knee osteoarthritis (OA). However, clinical studies on PRP injections reported controversial results. Bone marrow edema (BME) can cause symptoms by affecting the subchondral bone and it is not targeted by intra-articular treatments. The aim of this study was to investigate if the presence of BME can influence the outcome of intra-articular PRP injections in knee OA patients. A total of 201 patients were included in the study, 80 with and 121 without BME at the baseline MRI. BME area and site were evaluated, and BME was graded using the Whole-Organ Magnetic Resonance Imaging Score (WORMS). Patients were assessed with International Knee Documentation Committee (IKDC) score Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, the EuroQol-Visual Analogue Scale (EQ-VAS), and the Tegner score at baseline, 2, 6, and 12 months. Overall, the presence of BME did not influence the clinical results of intra-articular PRP injections in these patients treated for knee OA. Patients with BME presented a similar failure rate and clinical improvement after PRP treatment compared to patients without BME. The area and site of BME did not affect clinical outcomes. However, patients with a higher BME grade had a higher failure rate.

Mucoid degeneration of the anterior cruciate ligament: can platelet-rich plasma combined with reductionplasty provide better results?

Introduction: Mucoid degeneration of the anterior cruciate ligament (ACL) is commonly treated with arthroscopic debridement of the ACL. But many studies have reported the weakening and laxity of ACL postoperatively and on follow-up. Platelet-rich plasma (PRP) is known to influence musculoskeletal healing through multiple growth factors. Methodology: Five patients who were diagnosed as a case of mucoid degeneration of the ACL based on MRI, over a period of 1 year (December 2018-2019), were included in the study. Autologous PRP, prepared by double spin protocol, was injected into the remaining ACL after partial debridement was done. Results: Visual analogue scale and Lysholm scores improved compared with preoperative scores, along with strength (anterior drawer test and Lachman test). Conclusion: PRP can be used to improve the healing and strength of a weakened ACL after partial debridement, but further research is needed to demonstrate its efficacy.

Platelet-rich plasma inhibits inflammation, apoptosis, and the NLRP3/Caspase-1 pathway and induces matrix metalloproteinases and proliferation of IL-1β-induced articular chondrocytes by downregulating T-box transcription factor 3

Objectives

Osteoarthritis (OA) is a chronic joint disease characterized by osteoproliferation and the degeneration and destruction of articular cartilage. Platelet-rich plasma (PRP) is rich in various growth factors that have been reported to promote bone defect repair. This study examined the specific role and mechanism of PRP in OA.

Methods

OA model cells were created by treating articular chondrocytes with IL-1β. After treatment of the model cells with PRP or/and a T-box transcription factor 3 (TBX3)-overexpression plasmid, TBX3 expression was monitored via RT-qPCR, western blotting, and immunofluorescence assays. IL-1β, IL-33, and Caspase-3 levels were detected with ELISA kits. Levels of NLRP3, Caspase-1, MMP9, MMP13, and COL2A1 expression were evaluated by western blotting, and cell proliferation was assessed by the CCK-8 assay.

Results

Our results showed that TBX3 expression was upregulated in IL-1β-induced articular chondrocytes. IL-1β stimulation induced inflammation and the production of matrix metalloproteinases, activated Caspase-3 and the NLRP3/Caspase-1 pathway, inhibited the proliferation of articular chondrocytes; however, all those affects mediated by IL-1β could be markedly reversed by PRP. We also found that PRP alleviated IL-1β-induced inflammation, apoptosis, and extracellular matrix degradation in articular chondrocytes by inhibiting TBX3. Our findings suggest that PRP alleviates OA progression in vitro by downregulating TBX3.

Conclusion

PRP suppressed OA progression in vitro by inhibiting TBX3, which may be its mechanism of action in treating OA.

VEGF-attenuated platelet-rich plasma improves therapeutic effect on cartilage repair

Autologous platelet-rich plasma (PRP) has gained popularity as a less invasive treatment for various musculoskeletal tissue injuries and conditions due to its favorable safety profile, minimal manipulation and cost-effectiveness. Although PRP treatment has been clinically used for the treatment of osteoarthritis (OA) and damaged cartilage, evidence on therapeutic efficacy has been inconsistent, which calls for a methodology to achieve consistent and improved treatment outcomes. Given that PRP contains numerous proteins, we hypothesized that attenuation of a growth factor known to be detrimental to the healing tissue would enhance efficacy of PRP treatment. Considering that VEGF-mediated angiogenesis inhibits the repair of articular cartilage, we developed VEGF-attenuated PRP by sequestering VEGF in PRP using VEGF-binding microspheres. We demonstrated that VEGF attenuation in PRP did not inhibit the effect of PRP on chondrogenic differentiation of stem cells in vitro. In addition, healing of rat OA cartilage was significantly improved after treatment with VEGF-attenuated PRP when compared to the PRP treatment group or PBS control group. We expect that attenuation of unwanted biological activity using growth factor-binding microspheres could provide a new PRP customization method broadly applicable to various tissue repair processes.

Platelet-Rich Plasma and Adipose-Derived Mesenchymal Stem Cells in Association with Arthroscopic Microfracture of Knee Articular Cartilage Defects: A Pilot Randomized Controlled Trial

Background

This study aims to compare the effects of platelet-rich plasma (PRP) alone or in combination with adipose-derived mesenchymal stem cells (AD-MSCs) in patients affected by cartilage defects, undergoing knee arthroscopic microfracture.

Methods

Thirty-eight patients diagnosed with a knee monocompartmental cartilage defect (Outerbridge grade IV) on the MRI, underwent an arthroscopic procedure. After the confirmation of the lesion, they all received the same bone marrow stimulation technique (microfracture) and were randomized into two groups: the first one had additional PRP injection (group A), while the second received PRP and AD-MSC injection (group B). Knee assessment and pain score were documented with Knee Injury Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score, Short-Form (SF) 12, and Visual Analogue Scale (VAS) before the treatment and at 1, 3, 6, and 12 months of follow-up postoperatively. An additional arthroscopic procedure, performed in four patients for a subsequent meniscal lesion, let us evaluate cartilage evolution by performing a macro/microscopical assessment on cartilage biopsy specimens.

Results

At the 12-month follow-up, both groups showed a comparable functional improvement. The scores on the IKDC form, KOOS, pain VAS, and SF-12 significantly improved from baseline (p < 0.05) to 12 months postoperatively in both treatment groups. The four second-look arthroscopies showed a complete repair of the articular defects by smooth solid cartilage layer, with a good chondrocytic population, in both groups. A thick smooth hyaline-like cartilage with a predominantly viable cell population and normal mineralization (a form closely resembling native tissue) was observed in group B.

Conclusions

Modern regenerative medicine techniques, such as PRP and AD-MSC, associated with traditional arthroscopic bone marrow stimulating techniques, seem to enhance cartilage restoration ability. The preliminary results of this pilot study encourage the synergic use of these regenerative modulating systems to improve the quality of the regenerated cartilage.

Fixation of platelet-rich plasma and fibrin gels on knee cartilage defects after microfracture with arthroscopy

PURPOSE

An investigation of arthroscopic surgery combined with coverage of the microfractured wound surface with platelet-rich plasma (PRP) and fibrin gels (FG) to treat knee cartilage defects.

METHODS

Between February 2017 and February 2020, 145 patients with knee cartilage defects were treated. Only isolated full-thickness cartilage defects were included, and 28 patients (12 men and 16 women) were included in this study. They were all treated with arthroscopic surgery on subchondral bones, filled with PRP and thrombin, and sealed with FG. The knee pain visual analogue scale (VAS) scores were measured after the patients climbed ten stairs up and down, and the Western Ontario and McMaster Universities osteoarthritis index and the area of cartilage defects were measured through the pre-operative and post-operative follow-up. The complication incidences were also observed.

RESULTS

All patients were followed up for ten to 15 months (median 12 months). The knee pain VAS scores decreased from 6.57 ± 1.07 pre-operatively to 2.09 ± 1.35 at the last follow-up. The WOMAC osteoarthritis index decreased from 44.32 ± 3.95 (mean ± sd) pre-operatively to 16.57 ± 2.20 by the last follow-up. The cartilage defect decreased from 2.93 ± 0.65 cm² pre-operatively to 1.09 ± 0.69 cm² at the last follow-up. All scores showed statistically significant improvements after surgery (p < 0.05). No complications were observed.

CONCLUSION

The combination therapy of arthroscopic surgery and covering the microfractured wound surface with PRP and FG can repair knee cartilage defects, relieve pain, and improve function, and is a safe and effective treatment.

Clinical Response After Treatment of Knee Osteoarthritis With a Standardized, Closed-System, Low-Cost Platelet-Rich Plasma Product: 1-Year Outcomes

Background:

Intra-articular infiltration of platelet-rich plasma (PRP) is an alternative therapeutic option to classic hyaluronic acid for the treatment of symptomatic knee osteoarthritis (KOA). However, variation in preparation methods and quality assessment of PRP makes the study of its real clinical efficacy difficult.

Purpose:

To (1) evaluate the clinical efficacy of a characterized PRP product prepared in a standardized manner and in a closed-system for the treatment of KOA and to (2) evaluate the association of the clinical response to PRP-related variables.

Study Design:

Case series; Level of evidence, 4.

Methods:

We recruited 130 patients with nonoperative KOA and evaluated them for 1 year. PRP was prepared from a donation of autologous blood, obtaining 3 aliquots of approximately 10mL of product, which were frozen, allowing platelet disruption, platelet factor release, and long-term storage, until administration. Patients were treated 3 consecutive times every 4 weeks with an intra-articular PRP knee injection under sterile conditions. Complete blood count was performed on the whole-blood sample and the processed PRP before freezing it, for product quality assessment. Patients were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and basic satisfaction scale at 3 months, 6 months, and 1 year after intervention.

Results:

Quality assessment confirmed a leukocyte-poor PRP product (white blood cell count, 0.09 ± 0.09 × 10⁹/L) with a high platelet purity (platelet count, 630.86 ± 191.75 × 10⁹/L). WOMAC scores improved, and basic satisfaction was achieved in 70% of patients. No adverse events were reported. No correlations were observed between PRP quality parameters and clinical results. PRP complete treatment production costs were €108/US$125 (€36/US$41.6 per injection).

Conclusion:

This standardized PRP production method resulted in improved WOMAC scores at 1 year postoperatively in 70% of patients with KOA. This technique was safe and affordable and ensured consecutive infiltrations with the same product to each patient.

Intra-Articular Injections of Autologous Adipose Tissue or Platelet-Rich Plasma Comparably Improve Clinical and Functional Outcomes in Patients with Knee Osteoarthritis

The use of biologic therapies for the management of knee osteoarthritis (OA) has largely increased in recent years. The purpose of this study was to evaluate the efficiency and the therapeutic potential of platelet-rich plasma (PRP) and autologous adipose tissue (AAT) injections as a treatment for knee OA. Sixty participants were enrolled in the study: 20 healthy ones and 40 with minimal to moderate knee OA (KL I-III). The OA patients were randomly assigned either to the PRP or to the AAT group. The PRP samples showed a low expression level of NF-κB-responsive gene CCL5 and high expression levels of classic inflammatory and TNF-l INF responses. The AAT injection product was prepared using a Lipogems device, and its regenerative potential as well as the ability for expansion of mesenchymal stem cells were tested in the cell culture conditions. The patient assessments were carried out five times. Significant improvement was observed regardless of the treatment method in the VAS, KOOS, WOMAC and IKDC 2000 subjective evaluations as well as in the functional parameters. Intra-articular injections of AAT or PRP improved pain, symptoms, quality of life and functional capacity with a comparable effectiveness in the patients with mild to moderate knee osteoarthritis.

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).

Efficacy and safety of radiofrequency treatment for improving knee pain and function in knee osteoarthritis: a meta-analysis of randomized controlled trials

Background

The clinical utility of radiofrequency (RF) in patients with knee osteoarthritis (OA) remains unclear. We conducted a meta-analysis to systematically evaluate the efficacy and safety of RF treatment in patients with knee OA.

Methods

Searches of the PubMed, Web of Science, EMBASE, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Data databases were performed through August 30, 2021. The major outcomes from published randomized controlled trials (RCTs) involving patients with knee OA were compared between RF and control groups, including Visual Analogue Scale (VAS) or Numerical Rating Scale (NRS) scores, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), Global Perceived Effect (GPE) scale, and adverse effects at available follow-up times.

Results

Fifteen RCTs involving 1009 patients were included in this meta-analysis, and the results demonstrated that RF treatment correlated with improvements in pain relief (VAS/NRS score, all P < 0.001) and knee function (WOMAC, all P < 0.001) at 1–2, 4, 12, and 24 weeks after treatment as well as patients’ degree of satisfaction with treatment effectiveness (GPE scale, 12 weeks, P < 0.001). OKSs did not differ significantly between the two groups. Moreover, treatment with RF did not significantly increase adverse effects. Subgroup analysis of knee pain indicated that the efficacy of RF treatment targeting the genicular nerve was significantly better than intra-articular RF at 12 weeks after treatment (P = 0.03).

Conclusions

This meta-analysis showed that RF is an efficacious and safe treatment for relieving knee pain and improving knee function in patients with knee OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02906-4.

Applications of the regenerative capacity of platelets in modern medicine

Platelets produce platelet growth factors such as PDGF, IGF-1, EGF-, HGF, TGFβ, bFGF, and VEGF, which are crucial in regulating all stages of the wound healing process. The source of these substances is platelet-rich plasma (PRP). Over the past five decades, the interest and use of the regenerative properties of platelets have increased significantly in many different fields of medicine around the world. PRP and PRF plate preparations are used in: 1. Dentistry (they reduce bleeding, facilitate and accelerate soft tissue healing and bone regeneration - FGF 2, IGF-1, IGF-2, TGF-β1, and PDGF); 2. Sports medicine - IGF-1, IGF-2, TGF-β, VEGF, PDGF and bFGF, EGF); 3. dermatology and cosmetology (treatment of alopecia, hair reconstruction - FGF-7, HGF, acne scars, skin rejuvenation and regeneration, treatment of chronic and poorly healing wounds, burns, and acquired vitiligo); 4. Gynecology and reproductive medicine (treatment of infertility, erectile dysfunction - PDGF-β, TGF-β, IGF-1, in sexual dysfunction - PDGF, in vaginal atrophy); 5 Ophthalmology (in the healing of corneal epithelial wounds, in the treatment of dormant corneal ulcers, dry eye syndrome and the reconstruction of the corneal surface; 6. Neurology (regeneration of neurons, pain alleviation, and clinical symptoms - TGF-β 1, IGF-1, PDGF, VEGF) and FGF). Platelet-rich plasma therapy is a very interesting alternative and complement to traditional methods of treatment. However, the potential for using platelets is still not fully understood. The composition of platelet-rich plasma depends on many factors that may affect its use's efficacy and clinical benefits. Further research is necessary to standardize PRP delivery's preparation procedures and methods for a specific disease entity or clinical case.

Novel assessment of leukocyte-rich platelet-rich plasma on functional and patient-reported outcomes in knee osteoarthritis: a pilot study

Background: Leukocyte-rich platelet-rich plasma (LR-PRP) has demonstrated to be beneficial for patients with knee osteoarthritis (KOA); however, reliable objective end points to accurately assess its therapeutic effects is lacking. Aim: To investigate the efficacy of LR-PRP as assessed by functional and patient-reported outcomes at early time points (6 weeks). Materials & methods: We conducted a prospective cohort study in 12 patients with diagnosed KOA (Kellgren Lawrence score of II-III), who underwent a single ultrasound-guided LR-PRP injection. Results: There was significant improvement in timed up and go, pain and quality of life scales and balance parameters. There were nonsignificant improvements in range of motion and gait parameters. Conclusion: LR-PRP demonstrates efficacy in meaningful end points for functional and patient-reported outcomes at early time points in patients with KOA.

A Pilot Clinical Study of Hyperacute Serum Treatment in Osteoarthritic Knee Joint: Cytokine Changes and Clinical Effects

The serum fraction of platelet-rich fibrin (hyperacute serum) has been shown to improve cartilage cell proliferation in in vitro osteoarthritic knee joint models. We hypothesize that hyperacute serum may be a potential regenerative therapeutic for osteoarthritic knees. In this study, the cytokine milieu at the synovial fluid of osteoarthritic knee joints exposed to hyperacute serum intraarticular injections was investigated. Patients with knee osteoarthritis received three injections of autologous hyperacute serum; synovial fluid was harvested before each injection and clinical monitoring was followed-up for 6 months. Forty osteoarthritic-related cytokines, growth factors and structural proteins from synovial fluid were quantified and analysed by Multivariate Factor Analysis. Hyperacute serum provided symptomatic relief regarding pain and joint stability for OA patients. Both patients "with" and "without effusion knees" had improved VAS, KOOS and Lysholm-Tegner scores 6 months after of hyperacute serum treatment. Synovial fluid analysis revealed two main clusters of proteins reacting together as a group, showing strong and significant correlations with their fluctuation patterns after hyperacute serum treatment. In conclusion, hyperacute serum has a positive effect in alleviating symptoms of osteoarthritic knees. Moreover, identified protein clusters may allow the prediction of protein expression, reducing the number of investigated proteins in future studies.

Role of Physical Exercise and Nutraceuticals in Modulating Molecular Pathways of Osteoarthritis

Osteoarthritis (OA) is a painful and disabling disease that affects millions of patients. Its etiology is largely unknown, but it is most likely multifactorial. OA pathogenesis involves the catabolism of the cartilage extracellular matrix and is supported by inflammatory and oxidative signaling pathways and marked epigenetic changes. To delay OA progression, a wide range of exercise programs and naturally derived compounds have been suggested. This literature review aims to analyze the main signaling pathways and the evidence about the synergistic effects of these two interventions to counter OA. The converging nutrigenomic and physiogenomic intervention could slow down and reduce the complex pathological features of OA. This review provides a comprehensive picture of a possible signaling approach for targeting OA molecular pathways, initiation, and progression.

Efficacy and safety of radiofrequency ablation for treatment of knee osteoarthritis: a meta-analysis of randomized controlled trials

Objective

To evaluate the efficacy and safety of radiofrequency ablation for the treatment of knee osteoarthritis.

Methods

A literature review was conducted using the PubMed, Cochrane Review, Embase, and Google Scholar databases. Two reviewers independently assessed the eligibility of all retrieved studies. The research was reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to ensure the reliability and verity of the results. The statistical analysis was performed using STATA version 13.0.

Results

Nine randomized controlled trials were collected for the data extraction and meta-analysis. Significant differences in the pain score at 4, 12, and 24 weeks were found between patients treated with radiofrequency ablation and those treated with placebo. Furthermore, the use of radiofrequency ablation was associated with an improved outcome of the Western Ontario and McMaster Universities Arthritis Index at 4, 12, and 24 weeks. No serious adverse events were observed in any patients who underwent radiofrequency ablation.

Conclusion

Radiofrequency ablation is efficacious and safe for reducing pain and improving knee function in patients with knee osteoarthritis, without increasing the risk of adverse effects.

The 2020 NBA Orthobiologics Consensus Statement

This 2020 NBA Orthobiologics Consensus Statement provides a concise summary of available literature and practical clinical guidelines for team physicians and players. We recognize that orthobiologic injections are a generally safe treatment modality with a significant potential to reduce pain and expedite early return to play in specific musculoskeletal injuries. The use of orthobiologics in sports medicine to safely reduce time loss and reinjury is of considerable interest, especially as it relates to the potential effect on a professional athlete. While these novel substances have potential to enhance healing and regeneration of injured tissues, there is a lack of robust data to support their regular use at this time. There are no absolutes when considering the implementation of orthobiologics, and unbiased clinical judgment with an emphasis on player safety should always prevail. Current best evidence supports the following: Key Points There is support for the use of leukocyte-poor platelet-rich plasma in the treatment of knee osteoarthritis. There is support for consideration of using leukocyte-rich platelet-rich plasma for patellar tendinopathy. The efficacy of using mesenchymal stromal cell injections in the management of joint and soft tissue injuries remains unproven at this time. There are very few data to suggest that current cell therapy treatments lead to any true functional tissue regeneration. Meticulous and sterile preparation guidelines must be followed to minimize the risk for infection and adverse events if these treatments are pursued.Given the high variability in orthobiologic formulations, team physicians must stay up-to-date with the most recent peer-reviewed literature and orthobiologic preparation protocols for specific injuries.Evidence-based treatment algorithms are necessary to identify the optimal orthobiologic formulations for specific tissues and injuries in athletes.Changes in the regulatory environment and improved standardization are required given the exponential increase in utilization as novel techniques and substances are introduced into clinical practice.

Osteoarthritis In Vitro Models: Applications and Implications in Development of Intra-Articular Drug Delivery Systems

Osteoarthritis (OA) is a complex multi-target disease with an unmet medical need for the development of therapies that slow and potentially revert disease progression. Intra-articular (IA) delivery has seen a surge in osteoarthritis research in recent years. As local administration of molecules, this represents a way to circumvent systemic drug delivery struggles. When developing intra-articular formulations, the main goals are a sustained and controlled release of therapeutic drug doses, taking into account carrier choice, drug molecule, and articular joint tissue target. Therefore, the selection of models is critical when developing local administration formulation in terms of accurate outcome assessment, target and off-target effects and relevant translation to in vivo. The current review highlights the applications of OA in vitro models in the development of IA formulation by means of exploring their advantages and disadvantages. In vitro models are essential in studies of OA molecular pathways, understanding drug and target interactions, assessing cytotoxicity of carriers and drug molecules, and predicting in vivo behaviors. However, further understanding of molecular and tissue-specific intricacies of cellular models for 2D and 3D needs improvement to accurately portray in vivo conditions.

Reviewing the evidence for shockwave- and cell-based regenerative therapies in the treatment of erectile dysfunction

Erectile dysfunction (ED) is both a common and complex disease process. Existing ED treatments do not always achieve adequate results. There is clinical interest in employing regenerative therapies, including low-intensity extracorporeal shockwave therapy (Li-ESWT), platelet rich plasma (PRP), and stem cell therapy (SCT), in the treatment of ED as adjunct or alternative treatments. Here, we present evidence for emerging shockwave- and cell-based regenerative therapies for the treatment of ED following a thorough review of the existing PubMed literature pertaining to Li-ESWT, PRP, and SCT in relation to the treatment of ED. Li-ESWT causes microtrauma in tissue that hypothetically upregulates angiogenesis and recruits stem cells. Several large-scale systematic reviews and meta-analyses have reported that Li-ESWT improved ED in humans. Additionally, evidence has commenced to show that Li-ESWT may be effective against two recognized and complex etiologies of ED: diabetic and neurogenic. PRP delivers an autologous sample rich in growth factors to damaged tissue. Animal model studies have demonstrated improved erectile function recovery as well as preservation of cavernous nerve axons. Studies with PRP in humans are limited. SCT utilizes the regenerative potential of stem cells for healing of damaged tissue. In the treatment of ED, SCT has been used in the setting of diabetic and post-prostatectomy ED. Results of human studies are varied, although SCT treatments did result in increased erectile rigidity with some patients recovering the ability to achieve penetration. While these regenerative therapies show potential to augment the current treatment regimen for ED, there is a paucity of evidence to support the safety and efficacy of these treatments. Further research is necessary to define the role of these alternative therapies in the treatment of ED.

Regenerative Injectable Therapies: Current Evidence

Regenerative medicine is a growing field of musculoskeletal treatments that focuses on amplifying the body's natural healing properties to improve function and pain after injury. Regenerative treatments are applied locally at the site of injury and work though different mechanisms, some of which are unexplained at this time. Current evidence demonstrates benefit for certain regenerative treatments, but further standardization of treatments and additional studies are required to provide additional data to support specific regenerative treatments. This review seeks to explore the evidence and discuss appropriate use of the most common regenerative treatments including platelet-rich plasma, prolotherapy, autologous mesenchymal stem cells, human-derived allograft products, and saline.

Short-term outcomes after pure bone marrow aspirate injection for severe knee osteoarthritis: a case series

Background: Bone marrow aspiration (BMA) is among a group of autologous cell-based therapies currently being explored to treat osteoarthritis (OA). Materials & methods: This retrospective case study observed ten patients (13 knees) with severe knee OA who failed extensive conservative treatment and were treated with BMA injection using a novel, pure bone marrow aspiration (pBMA) technique. Results: No adverse events were reported. More than 50% reduction in the visual analog scale score for pain was observed at 2- and 12-weeks post-procedure, showing statistical significance. At 64 ± 26 weeks post-procedure, average knee pain remained significantly less than pre-procedure. Conclusion: Therefore, patients with severe knee OA may achieve significant relief after a BMA injection obtained using this pure bone marrow aspiration technique.

Evidence on ankle injections for osteochondral lesions and osteoarthritis: a systematic review and meta-analysis

PURPOSE

To evaluate the evidence supporting safety and effectiveness of intra-articular injective treatments for ankle lesions ranging from osteochondral lesions of the talus (OLT) to osteoarthritis (OA).

METHODS

A systematic review and a meta-analysis were performed on PubMed, Embase, and Cochrane Library in March 2020. Safety was evaluated through the reported side effects and effectiveness through the scores used. The quality of the studies was assessed using the Cochrane Collaboration Risk of Bias 2.0 tool and the Downs and Black checklist. For each outcome, the quality of evidence was graded according to GRADE guidelines.

RESULTS

Twenty-four studies (21 for OA, 3 for OLT) were included on hyaluronic acid (HA), platelet-rich plasma (PRP), saline, methylprednisolone, botulinum toxin type A (BoNT-A), mesenchymal stem cells (MSCs), and prolotherapy. No severe adverse events were reported. For OLT, a comparison was possible between HA and PRP showing no significant difference. For ankle OA, a significant difference favouring HA versus saline was documented at six months (p < 0.001). The GRADE level of evidence was very low.

CONCLUSION

This meta-analysis supports the safety of intra-articular treatment for ankle OA and OLT, while only a very low evidence supports the efficacy of HA in terms of better results versus placebo for the treatment of ankle OA, and other conclusions are hindered by the scarcity of the available literature. This urges further and stronger trials to specifically investigate potential and limitations of these different injective approaches for the treatment of OLT and ankle OA.

Patient-Reported Outcomes After Platelet-Rich Plasma, Bone Marrow Aspirate, and Adipose-Derived Mesenchymal Stem Cell Injections for Symptomatic Knee Osteoarthritis

Objective:

The objective of this study was to compare platelet-rich plasma (PRP), bone marrow aspirate concentrate (BMAC), and adipose-derived mesenchymal stem cell (MSC) injections in the treatment of osteoarthritis (OA) of the knee using functional scores.

Methods:

A total of 89 patients with painful knee OA were included in this study. Patients were assigned to one of the 3 treatments according to severity of OA as indicated by symptoms and radiography to PRP (stage I), BMAC (stage II), or adipose-derived MSC (stage III). Clinical assessment was performed using the Knee Society Score, which combines the Knee Score, based on the clinical parameters, and the Functional Score, and IKDC score. Surveys were completed at preoperative and at 90, 180, and 265 days postoperative. The follow-up responses were compared with baseline and between treatment groups.

Results:

Treatment with PRP, BMAC, and adipose-derived MSC included 29 (32.6%), 27 (30.3%), and 33 (37.1%) patients, respectively. For the total group, median age was 61 years (range: 22-84 years). Score values were comparable among treatment groups at baseline. Statistically significant improvement was observed in the 3 groups according to the 3 scores at all time points during follow-up compared with baseline. No difference was found among treatment type.

Conclusions:

Our findings support previous reports and encourage further research on the use of these cost-effective treatments for OA of the knee.

Dose-Dependent Effects of Platelet-Rich Plasma Powder on Chondrocytes In Vitro

BACKGROUND

Platelet-rich plasma (PRP) is widely used in sports medicine. However, neither preparation nor parameters for clinical application, such as concentration, timing, and number of applications, are standardized, making research and clinical utilization challenging.

PURPOSE

To investigate the effect of varying doses of PRP powder in terms of different concentrations, timing, and number of applications on human chondrocytes in a reproducible cell culture model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A standardized lyophilized platelet growth factor preparation (PRP powder) was used to stimulate human chondrocytes. Chondrocytes were cultivated for 2 weeks with different stimulation frequencies (2×, 3×, 6×) and different concentrations of PRP powders (0.5%, 1%, 5%). Cell proliferation and metabolic cell activity were analyzed on days 7 and 14. Phenotypic changes were visualized through live-dead staining. Chondrogenic differentiation was quantified with enzyme-linked immunosorbent assay to assess the synthesis of procollagen types 1 and 2. Furthermore, sulfated proteoglycans and glycosaminoglycans were analyzed.

RESULTS

Human chondrocytes exhibited a significant dose- and time-dependent increase after 14 days in cell number (1% and 5% PRP powder vs unstimulated control: 7.95- and 15.45-fold increase, respectively; 2× vs 6× stimulation with 5% PRP powder: 4.00-fold increase) and metabolic cell activity (1% and 5% PRP powder vs unstimulated control: 3.27-fold and 3.58-fold change, respectively). Furthermore, cells revealed a significant increase in the amount of bone-specific procollagen type 1 (14 days, 1.94-fold) and sulfated glycosaminoglycans (14 days, 2.69-fold); however, no significant change was observed in the amount of cartilage-specific collagen type 2.

CONCLUSION

We showed that chondrocytes exhibit a significant dose- and time-dependent increase in cell number and metabolic cell activity. The standardized use of growth factor concentrates in cell culture models can contribute to clinical knowledge in terms of dosage and timing of PRP applications.

CLINICAL RELEVANCE

Problems with PRP, such as the absence of standardization, lack of consistency among studies, and unknown dosage, could be solved by using characterized PRP powder made by pooling and lyophilizing multiple platelet concentrates. The innovative PRP powder generates new possibilities for PRP research, as well as for the treatment of patients.

The use of cellular matrix in symptomatic knee osteoarthritis

Knee osteoarthritis is a degenerative "wear and tear" disorder affecting mainly population over 50 years old. It can also present in younger people, especially after an injury or as a part of other diseases. While many therapeutic options exist for knee osteoarthritis, none of them has the potential to cure this condition. Cellular Matrix represents a combination of natural non-crosslinked hyaluronic acid (HA), thixotropic cell separation gel, and sodium citrate anticoagulant solution. A combination of Cellular Matrix with autologous platelet-rich plasma (A-PRP) is a novel therapeutic approach to the management of knee osteoarthritis. It is assumed that the active components HA and PRP have a synergistic effect contributing to a better therapeutic outcome in patients with knee osteoarthritis. Physiotherapy could provide an additional benefit. This is a retrospective pilot study assessing the potential benefit of Cellular Matrix and A-PRP combined with physiotherapy in the management of chronic knee osteoarthritis. Twenty-five patients were enrolled in the study and injected with three doses of Cellular Matrix combined with A-PRP with a time span of 2 weeks between each injection. All patients received standardized physiotherapy. The results showed that 68% of patients achieved more than 50% improvement in pain, stiffness, and function of the knee joints. There were no adverse reactions. This retrospective pilot study confirmed the positive effect of PRP and HA combination in the management of mild and moderate knee osteoarthritis. These preliminary results need to be verified in randomized control trials.

Effects of submucosal PRP injection on wound healing in endonasal surgeries: an experimental study

PURPOSE

To investigate the effects of submucosal platelet-rich plasma (PRP) injection on nasal mucosal wound healing after endoscopic sinus surgery.

METHODS

24 New Zealand white rabbits were randomly divided into three groups. To mimic surgery, injury was created using 3-mm punch forceps on ventral turbinate mucosa for all groups. Submucosal PRP was injected to the damaged mucosa in the first group (PRP group, n = 8), where 0.9% saline solution to the second group (saline group, n = 8) and no injection to the third one (control group, n = 8). All the animals were sacrificed 14 days after surgery; histopathological examination and hydroxyproline measurements were performed on the mucosa of all groups.

RESULTS

Neutrophils, goblet cells, and collagen intensity were found significantly lower (p < 0.05) in PRP group than the control group. Also, the number of ciliary and goblet cells, and collagen intensity were found significantly lower (p < 0.05) in PRP group, than the saline group. In PRP group, hydroxyproline levels were found (p < 0.05) significantly lower than the saline and the control group, and no significant difference was found between the saline group and the control group (p > 0.05).

CONCLUSION

There are many studies in literature showing the positive effects of PRP on wound healing. The results of this study also demonstrated positive effects of PRP on the nasal mucosa. According to these results, PRP injection to the injured nasal mucosa showed anti-inflammatory, mucus-softening, and synechia-reducing effects. Therefore, submucosal PRP injection after endonasal surgeries can be considered an effective application for maintaining nasal physiology.

Procedural Treatments for Knee Osteoarthritis: A Review of Current Injectable Therapies

Knee osteoarthritis is a common painful degenerative condition affecting the aging Canadian population. In addition to pain and disability, osteoarthritis is associated with depression, comorbid conditions such as diabetes, and increased caregiver burden. It is predicted to cost the Canadian healthcare system $7.6 billion dollars by 2031. Despite its high cost and prevalence, controversy persists in the medical community regarding optimal therapies to treat knee osteoarthritis. A variety of medications like nonsteroidal anti-inflammatories and opioids can cause severe side effects with limited benefits. Total knee arthroplasty, although a definitive management, comes with risk such as postoperative infections, revisions, and chronic pain. Newer injectable therapies are gaining attention as alternatives to medications because of a safer side effect profile and are much less invasive than a joint replacement. Platelet-rich plasma is beginning to replace the more common injectable therapies of intra-articular corticosteroids and hyaluronic acid, but larger trials are needed to confirm this effect. Small studies have examined prolotherapy and stem cell therapy and demonstrate some benefits. Trials involving genicular nerve block procedures have been successful. As treatments evolve, injectable therapies may offer a safe and effective pathway for patients suffering from knee osteoarthritis.

An Analysis of Current Treatment Trends in Platelet-Rich Plasma Therapy in the Medicare Database

Background:

The use of platelet-rich plasma (PRP) in the Medicare population is not well described.

Purpose:

To investigate the national use of PRP among Medicare beneficiaries, including the incidence and conditions for which it was used in both operative and nonoperative settings, and determine charges to Medicare.

Study Design:

Descriptive epidemiology study.

Methods:

The Medicare Standard Analytical Files within the PearlDiver database were queried for PRP injections by use of Current Procedural Terminology (CPT) code 0232T from 2010 to 2014. A search of every associated International Classification of Diseases, 9th Revision, code and CPT code on the day of the injection was performed, and codes were broadly categorized as shoulder, knee, elbow, hip, and foot/ankle. These categories were then subdivided into 2 groups based on whether the injection was performed at the time of surgery or for a nonoperative condition. The patient data were analyzed by demographics and geographic region. In further analysis, the charges sent to Medicare for PRP injections were stratified by year and musculoskeletal site.

Results:

A total of 3654 PRP injections were coded for and administered during the study period; 57% of recipients were men and 33% were 65 to 69 years of age. We found that 42% of all PRP injections were administered in the southern geographic region. PRP injections were most commonly associated with shoulder diagnoses, followed closely by the foot and ankle and by the knee. The majority of injections given for shoulder conditions were performed at the time of surgery, whereas the majority of knee conditions treated with PRP were associated with nonoperative treatments. Annual charges to Medicare for PRP injections increased 400%, from $500,000 in 2010 to more than $2 million in 2014.

Conclusion:

The use and breadth of PRP therapy have increased substantially in Medicare beneficiaries. Further research is required to obtain a consensus on treatment recommendations for PRP use in this population in addition to strategies to obtain insurance reimbursement.

Platelet-Rich Plasma for Sport-Active Patients with Knee Osteoarthritis: Limited Return to Sport

Objective

To evaluate a cohort of sport-active patients suffering from cartilage degeneration and OA, in terms of clinical outcome and return to sport (RTS) after platelet-rich plasma (PRP) injective treatment.

Design

This study included forty-seven sport-active patients ≤50 years old with unilateral symptomatic knee cartilage degeneration or OA. Patients received 3 PRP injections and were prospectively evaluated at baseline and then at 2, 6, 12, and 24 months follow-up by IKDC subjective EQ-VAS, and Tegner scores. Furthermore, patients were asked about their RTS, in terms of return to any sport level or to their activity level before symptoms onset.

Results

IKDC subjective score improved significantly at all follow-ups, changing from 59.2 ± 13.6 to 70.6 ± 13 at 12 months and to 76.7 ± 12.5 at 24 months (p < 0.0005). A similar outcome was observed with the EQ-VAS score. Tegner score improved from 3.6 ± 1.4 to 4.8 ± 0.9 at 24 months (p < 0.0005). A similar outcome was observed with the EQ-VAS score. Tegner score improved from 3.6 ± 1.4 to 4.8 ± 0.9 at 24 months (p < 0.0005). A similar outcome was observed with the EQ-VAS score. Tegner score improved from 3.6 ± 1.4 to 4.8 ± 0.9 at 24 months (p < 0.0005). A similar outcome was observed with the EQ-VAS score. Tegner score improved from 3.6 ± 1.4 to 4.8 ± 0.9 at 24 months (

Conclusions

Sport-active patients affected by knee OA can benefit from PRP injections, with pain and function improvement over time. However, results are less satisfactory in terms of RTS since only half can achieve the same sport level as before the onset of symptoms. Patients undergoing PRP treatment should be made aware of their low chances to go back to high-impact sport activities.

Use of Adipose-Derived Orthobiologics for Musculoskeletal Injuries: A Narrative Review

Musculoskeletal injuries are among the most prevalent, disabling, and costly conditions that Americans face, affecting over half of those over 18 and nearly 75% of those over 65 years old. Current treatments are largely palliative for many of these conditions and unmet needs have warranted the emergence of alternative treatments. Orthobiologics, such as adipose tissue derivatives (ATDs), are of high interest because they can be obtained in the office setting and their cellular components, including adipose stem cells and stromal cells, are thought to be beneficial in the treatment of musculoskeletal injuries. Microfragmented adipose tissue (MFAT) and stromal vascular fraction (SVF) are two ATD injectates that are used in the clinical setting to treat musculoskeletal conditions. Our review aimed to clarify the terminology describing the various ATDs used for orthopedic indications while discussing the promising but low-quality evidence, heterogeneity in MFAT and SVF processing methods, and inconsistencies in reported information such as injectate characterization with cell counts, injection technique, and postprocedural rehabilitation.

Tendon and Ligament Healing and Current Approaches to Tendon and Ligament Regeneration

Ligament and tendon injuries are common problems in orthopedics. There is a need for treatments that can expedite nonoperative healing or improve the efficacy of surgical repair or reconstruction of ligaments and tendons. Successful biologically-based attempts at repair and reconstruction would require a thorough understanding of normal tendon and ligament healing. The inflammatory, proliferative, and remodeling phases, and the cells involved in tendon and ligament healing will be reviewed. Then, current research efforts focusing on biologically-based treatments of ligament and tendon injuries will be summarized, with a focus on stem cells endogenous to tendons and ligaments. Statement of clinical significance: This paper details mechanisms of ligament and tendon healing, as well as attempts to apply stem cells to ligament and tendon healing. Understanding of these topics could lead to more efficacious therapies to treat ligament and tendon injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:7-12, 2020.