Platelet-rich plasma: where are we now and where are we going?

Intraarticular triamcinolone hexacetonide, stanozolol, Hylan G-F 20 and platelet concentrate in a naturally occurring canine osteoarthritis model

Osteoarthritis (OA) is a disease transversal to all mammals, a source of chronic pain and disability, a huge burden to societies, with a significant toll in healthcare cost, while reducing productivity and quality of life. The dog is considered a useful model for the translational study of the disease, closely matching human OA, with the advantage of a faster disease progression while maintaining the same life stages. In a prospective, longitudinal, double-blinded, negative controlled study, one hundred (N = 100) hip joints were selected and randomly assigned to five groups: control group (CG, n = 20, receiving a saline injection), triamcinolone hexacetonide group (THG, n = 20), platelet concentrate group (PCG, n = 20), stanozolol group (SG, n = 20) and hylan G-F 20 group (HG). Evaluations were conducted on days 0 (T0, treatment day), 8, 15, 30, 60, 90, 120, 150 and 180 days post-treatment, consisting of weight distribution analysis and data from four Clinical Metrology Instruments (CMI). Kaplan-Meier estimators were generated and compared with the Breslow test. Cox proportional hazard regression analysis was used to investigate the influence of variables of interest on treatment survival. All results were analyzed with IBM SPSS Statistics version 20 and a significance level of p < 0.05 was set. Sample included joints of 100 pelvic limbs (of patients with a mean age of 6.5 ± 2.4 years and body weight of 26.7 ± 5.2 kg. Joints were graded as mild (n = 70), moderate (n = 20) and severe (n = 10) OA. No differences were found between groups at T0. Kaplan-Meier analysis showed that all treatments produced longer periods with better results in the various evaluations compared to CG. Patients in HG and PCG took longer to return to baseline values and scores. A higher impact on pain interference was observed in THG, with a 95% improvement over CG. PCG and HG experienced 57-81% improvements in functional evaluation and impairments due to OA, and may be a better options for these cases. This study documented the efficacy of several approaches to relieve OA clinical signs. These approaches varied in intensity and duration. HG and PCG where the groups were more significant improvements were observed throughout the follow-up periods, with lower variation in results.

Intra-articular Injections With Either Triamcinolone Hexacetonide, Stanozolol, Hylan G-F 20, or a Platelet Concentrate Improve Clinical Signs in Police Working Dogs With Bilateral Hip Osteoarthritis

Objectives: To compare the effect of intra-articular treatment with triamcinolone hexacetonide (TH), stanozolol, hyaluronan, and a platelet concentrate in police working dogs with bilateral hip osteoarthritis (OA). Study Design: Prospective, longitudinal, double-blinded, negative controlled study. Sample Population: Fifty police working dogs with naturally occurring hip OA. Methods: Animals were randomly assigned to a control group (CG, n = 10), TH group (THG, n = 10), platelet concentrate group (PCG, n = 10), stanozolol group (SG, n = 10), and Hylan G-F 20 group (HG). On days 0 (T0), 8, 15, 30, 90, and 180 days post-treatment, weight-bearing distribution was evaluated. In those days, and on days 60, 120, and 150, four clinical metrology instruments were completed. Kaplan-Meier estimators were conducted and compared with the log-rank test. Cox proportional hazard regression analysis was performed to determine treatment survival. Significance was set at p < 0.05. Results: Patients had a mean age of 6.5 ± 2.4 years and body weight of 26.7 ± 5.2 kg. At T0, hips were classified as mild (n = 35), moderate (n = 10), and severe (n = 5), according to the Orthopedic Foundation for Animals grading scheme. No differences were found between groups at that moment considering age, body weight, OFA hip score, and all assessments performed. All treatments improved clinical signs in various OA dimensions in some groups, with a broad effect interval. PCG showed a lower range of variation while maintaining a positive result for more extended periods (p < 0.01 for symmetry index and 0.01 < p < 0.04 in the majority of scores). Breed, age, sex, and OFA grade did not significantly influence response to treatment. Conclusions and Clinical Relevance: This is the first prospective, negative controlled, double-blinded study to compare the effect of a single administration of these IA treatments in dogs with hip OA. HG and PCG recorded more significant improvements throughout the 180-day follow-up. In particular, PCG also registered a lower variation in results, seemingly the best therapeutic option. Nevertheless, improvements were still observed in THG and SG, and these treatment options can be considered, mainly when the first two treatments are not available.

Application of platelet-rich plasma for canine osteoarthritis treatment - a clinical series

Osteoarthritis, also known as degenerative joint disease (DJD), is defined as a progressive and permanent long-term deterioration of the cartilage surrounding the joints. There is no known cause for primary DJD. However, there are a wide variety of causes for secondary DJD, such as trauma, abnormal wear of joints and cartilage, or a congenital defect present at birth such as an improperly formed hip. One of the most popular methods used to biologically enhance healing in the fields of orthopaedic surgery and medicine includes the use of autologous blood products, namely, platelet rich plasma (PRP). Reports suggest that PRP, presumably containing high levels of platelet growth factors, may promote the recovery of the affected cartilage. This case series presents clinical and radiographic findings of three dogs with osteoarthritis of the elbow and knee joints. Pain score were assessed by CBPI (Canine Brief Pain Inventory). Treatment with three-fold intra-articular application of PRP, obtained by double centrifugation method, resulted in significant improvement in the function of the affected joint. Therefore, it could be concluded that PRP was clinically effective in the treatment of osteoarthritis in these three cases.

New and Emerging Therapies for Alopecia Areata

Alopecia areata (AA) is an autoimmune condition that affects up to 2% of the general population. Currently available treatment options for AA are of limited efficacy and can be associated with adverse effects. The advancement in understanding of the genetic and molecular mechanisms of AA has led to the development of novel treatment options, with the Janus kinase (JAK) inhibitor class of drugs at the forefront of ongoing clinical trials. Platelet-rich plasma, fecal transplants, and cytokine-targeted therapy with ustekinumab and dupilumab have also been shown to regrow hair in patients with AA in individual case reports or small studies. Several other novel therapies have preliminary data or are being tested in clinical trials.

Assisted therapy with platelet-rich plasma for burn patients: A meta-analysis and systematic review

INTRODUCTION

Platelet-rich plasma (PRP) therapy has been used in different medical fields, but its effectiveness in burn wound healing remains debatable. In this study, we performed a systematic review and meta-analysis of the available evidence on burn patients treated with PRP to evaluate the safety and efficacy of the treatment.

METHODS

Randomized controlled trials evaluating the efficacy of PRP in patients with burn injuries were selected. Eligible retrospective studies were abstracted and assessed for the risk of bias by two reviewers and results of mean time to complete epithelization and wound closure rate in the included studies were analyzed. Studies on the correlation between PRP and burn wound healing published in English or Chinese before March 2020 were retrieved from PubMed.

RESULTS

Eight studies (including 449 patients) met our inclusion criteria. Qualitative analysis revealed that compared with the control group, the PRP group had significantly better wound closure rates at weeks 2 (mean difference (MD): 12.79 [95% confidence interval (CI): 7.08, 18.49]; I2: 0%; p < 0.0001) and 3 (MD: 12.66 [95% CI: 5.97, 19.34]; I2: 55%; p = 0.0002) and time to complete epithelialization (MD: -3.45 [95% CI: -4.87, -2.04] (days); I2: 0%; p < 0.00001). There was no significant difference in infection rate or graft take rate.

CONCLUSIONS

PRP application can accelerate wound closure, however, it has no effect on the rates of wound infection and graft take rate.

Effects of platelet-rich plasma on the healing of sternal wounds: A meta-analysis

Sternal wound infection (SWI) is a devastating complication after cardiac surgery. Platelet-rich plasma (PRP) may have a positive impact on sternal wound healing. A systematic review with meta-analyses was performed to evaluate the clinical effectiveness of topical application of autologous PRP for preventing SWI and promoting sternal wound healing compared to placebo or standard treatment without PRP. Relevant studies published in English or Chinese were retrieved from the Cochrane Central Register of Controlled Trials (The Cochrane Library), PubMed, Ovid EMBASE, Web of Science, Springer Link, and the WHO International Clinical Trials Registry Platform (ICTRP) using the search terms "platelet-rich plasma" and "sternal wound" or "thoracic incision." References identified through the electronic search were screened, the data were extracted, and the methodological quality of the included studies was assessed. The meta-analysis was performed for the following outcomes: incidence of SWI, incidence of deep sternal wound infection (DSWI), postoperative blood loss (PBL), and other risk factors. In the systematic review, totally 10 comparable studies were identified, involving 7879 patients. The meta-analysis for the subgroup of retrospective cohort studies (RSCs) showed that the incidence of SWI and DSWI in patients treated with PRP was significantly lower than that in patients without PRP treatment. However, for the subgroup of randomized controlled trials (RCTs), there was no significant difference in the incidence of SWI or DSWI after intervention between the PRP and control groups. There was no significant difference in PBL in both RCTs and RSCs subgroups. Neither adverse reactions nor in-situ recurrences were reported. According to the results, PRP could be considered as a candidate treatment to prevent SWI and DSWI. However, the quality of the evidence is too weak, and high-quality RCTs are needed to assess its efficacy on preventing SWI and DSWI.

Clinical efficacy of platelet-rich plasma as adjuvant therapy in patients undergoing arthroscopic repair of meniscal injury

Objective

The clinical efficacy of platelet-rich plasma (PRP) as adjuvant therapy in patients undergoing arthroscopic repair of meniscal injury remains controversial. This meta-analysis was performed to evaluate the clinical efficacy of PRP in the treatment of meniscal injury and provide evidence for the selection of clinical treatment options.

Methods

A computer-based search of the PubMed, Embase, and Cochrane Library databases was performed to retrieve articles using the search terms “platelet-rich plasma” and “menisci.” Quality evaluation and data extraction were performed. The combined effect was assessed using RevMan version 5.3 software.

Results

Three randomized controlled trials and three cohort studies involving 293 patients were included in the meta-analysis. There were no significant differences in the International Knee Documentation Committee score or Lysholm score between the experimental and control groups. The failure rate and visual analog scale score were significantly lower and the degree of active flexion was significantly higher in the experimental group than in the control group.

Conclusion

The findings of this meta-analysis suggest that PRP injection can effectively enhance the efficacy of arthroscopic repair of meniscal injury, reduce the failure rate and severity of pain, and improve active flexion.

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-Derived Growth Factor vs Hyaluronic Acid Injection in the Individuals with Knee Osteoarthritis: A One Year Randomized Clinical Trial

OBJECTIVE

In this study, we aimed at performing a comparison between intra-articular injections of PRP-derived growth factor (PGRF) and hyaluronic acid regarding their effect on pain and patient's function in knee osteoarthritis, as well as their safety profiles.

METHODS

During our single-masked randomized clinical trial, the candidates with symptomatic knee osteoarthritis received two intra-articular injections of PRGF with 3 weeks apart or received three weekly injections of HA. The mean improvements from before treatment until the second, sixth, and twelfth months post-intervention in scores obtained by visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lequesne index were our primary outcomes.

RESULTS

A total of 102 candidates were finally included in the study. Patients' mean age was 57.08±7.3 years old in the PRGF group compared to the mean age of 58.63±7.09 years old in HA patients. In the PRGF group, total WOMAC index decreased from 41.96±11.71 to 27.10±12.3 (P = 0.02), and from 39.71±10.4 to 32.41±11.8 in the HA group after 12 months (P > 0.05). Regarding the Lequesne index, pain, ADL, and global scores significantly decreased after 12 months in the PRGF group compared to the HA group (P<0.001). There was also a meaningful higher rate of satisfaction in the PRGF group compared to the HA group after 12 months of treatment (P<0.001).

CONCLUSION

Besides significantly higher satisfaction belonging to the PRGF group, there was a statistically significant improvement in VAS score and global, pain, and ADL score of Lequesne by passing 12 months from injection in PRGF compared to HA.

Application of platelet-rich plasma in the in vitro production of bovine embryos

The aim of this study was to replace fetal bovine serum (FBS) with platelet-rich plasma (PRP) for in vitro production of bovine embryos. The maturation media (TCM-199 medium) for the cumulus-oocyte complexes (COCs) was supplemented with 5% (G5) and 10% (G10) PRP or 10% FBS (GC). After fertilization, the presumed zygotes were randomly distributed in culture medium supplemented with 5% (G5) and 10% (G10) PRP or 10% FBS (GC) for 7 days. Cumulus cell (CC) expansion was greater (P < 0.05) in the GC (88.9%) group than in G5 (34.1%) or G10 (50.0%). Nevertheless, the expansion of CCs in group G10 was greater than in G5 (P < 0.05). Cleavage was higher in group G5 (86.0%) than in G10 (79.0%) (P < 0.05) and did not differ from group GC (82.0%). The percentage of blastocysts in group G5 (50.0%) was higher than in CG (40.2%) and G10 (34.2%) (P < 0.05). In addition, the number of blastomeres was higher in G5 (159.0 ± 4.18) than in GC (132.4 ± 4.11) and in G10 (127.1 ± 5.88) (P < 0.05). The addition of PRP into the oocytes maturation medium is not beneficial. On the other hand, the PRP addition into the embryo culture medium at 5% concentration is recommended where it increased the quantity and quality of in vitro-produced bovine embryos.

Augmentation of Meniscal Repair With Platelet-Rich Plasma: A Systematic Review of Comparative Studies

Background:

The effect of platelet-rich plasma (PRP) augmentation for meniscal repair (MR) is unclear, as current evidence is limited to small, mostly nonrandomized studies.

Purpose:

To systematically review the literature to evaluate the efficacy and safety of MR with PRP augmentation.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to identify studies (level of evidence 1-3) that compared the clinical efficacy of MR performed with versus without PRP. The search phrase used was platelet-rich plasma meniscus. Patients were assessed based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the visual analog scale (VAS) for pain, the Lysholm score, the Knee injury and Osteoarthritis Outcome Score (KOOS), the subjective International Knee Documentation Committee (IKDC) score, and treatment failure.

Results:

We identified 6 studies (2 studies with level 1 evidence; 4 studies with level 3 evidence) that met inclusion criteria, for a total of 309 patients undergoing MR with PRP (mean age, 31.9 years) and 445 patients without PRP augmentation (mean age, 29.6 years). The mean follow-up was 32.8 months (range, 12-72 months). Overall, 17.0% of PRP patients experienced MR failure compared with 22.1% of non-PRP patients. No differences in VAS, Lysholm, or subjective IKDC scores were found between groups except in 1 study, in which postoperative subjective IKDC scores were significantly better in the PRP group (P < .01). Another study found significantly better postoperative WOMAC scores among PRP patients, and 2 studies found significantly better KOOS subscores among PRP patients.

Conclusion:

There are a limited number of high-quality studies comparing outcomes and healing rates between patients undergoing MR with versus without PRP augmentation. Based on the available evidence, patients undergoing MR with PRP augmentation experience similar clinical outcomes at midterm follow-up when compared with conventional MR, and additional studies are needed to determine the efficacy of MR augmented with PRP.

Platelet-Rich Plasma Modulates Gap Junction Functionality and Connexin 43 and 26 Expression During TGF-β1-Induced Fibroblast to Myofibroblast Transition: Clues for Counteracting Fibrosis

Skeletal muscle repair/regeneration may benefit by Platelet-Rich Plasma (PRP) treatment owing to PRP pro-myogenic and anti-fibrotic effects. However, PRP anti-fibrotic action remains controversial. Here, we extended our previous researches on the inhibitory effects of PRP on in vitro transforming growth factor (TGF)-β1-induced differentiation of fibroblasts into myofibroblasts, the effector cells of fibrosis, focusing on gap junction (GJ) intercellular communication. The myofibroblastic phenotype was evaluated by cell shape analysis, confocal fluorescence microscopy and Western blotting analyses of α-smooth muscle actin and type-1 collagen expression, and electrophysiological recordings of resting membrane potential, resistance, and capacitance. PRP negatively regulated myofibroblast differentiation by modifying all the assessed parameters. Notably, myofibroblast pairs showed an increase of voltage-dependent GJ functionality paralleled by connexin (Cx) 43 expression increase. TGF-β1-treated cells, when exposed to a GJ blocker, or silenced for Cx43 expression, failed to differentiate towards myofibroblasts. Although a minority, myofibroblast pairs also showed not-voltage-dependent GJ currents and coherently Cx26 expression. PRP abolished the TGF-β1-induced voltage-dependent GJ current appearance while preventing Cx43 increase and promoting Cx26 expression. This study adds insights into molecular and functional mechanisms regulating fibroblast-myofibroblast transition and supports the anti-fibrotic potential of PRP, demonstrating the ability of this product to hamper myofibroblast generation targeting GJs.

PI3K/Akt signaling pathway is essential for de novo hair follicle regeneration

Background

Cultured epidermal stem cells (Epi-SCs) and skin-derived precursors (SKPs) were capable of reconstituting functional hair follicles after implantation, while the signaling pathways that regulate neogenic hair follicle formation are poorly investigated. In this study, we aimed to understand the interactions between Epi-SCs and SKPs during skin organoid formation and to uncover key signal pathways crucial for de novo hair follicle regeneration.

Methods

To track their fate after transplantation, Epi-SCs derived from neonatal C57BL/6 mice were labeled with tdTomato, and SKPs were isolated from neonatal C57BL/6/GFP mice. A mixture of Epi-SCs-tdTomato and SKPs-EGFP in Matrigel was observed under two-photon microscope in culture and after implantation into excisional wounds in nude mice, to observe dynamic migrations of the cells during hair follicle morphogenesis. Signaling communications between the two cell populations were examined by RNA-Seq analysis. Potential signaling pathways revealed by the analysis were validated by targeting the pathways using specific inhibitors to observe a functional loss in de novo hair follicle formation.

Results

Two-photon microscopy analysis indicated that when Epi-SCs and SKPs were mixed in Matrigel and cultured, they underwent dynamic migrations resulting in the formation of a bilayer skin-like structure (skin organoid), where Epi-SCs positioned themselves in the outer layer; when the mixture of Epi-SCs and SKPs was grafted into excisional wounds in nude mice, a bilayer structure resembling the epidermis and the dermis formed at the 5th day, and de novo hair follicles generated subsequently. RNA-Seq analysis of the two cell types after incubation in mixture revealed dramatic alterations in gene transcriptome, where PI3K-Akt signaling pathway in Epi-SCs was significantly upregulated; meanwhile, elevated expressions of several growth factors and cytokine potentially activating PI3K were found in SKPs, suggesting active reciprocal communications between them. In addition, inhibition of PI3K or Akt by specific inhibitors markedly suppressed the hair follicle regeneration mediated by Epi-SCs and SKPs.

Conclusions

Our data indicate that the PI3K-Akt signaling pathway plays a crucial role in de novo hair follicle regeneration, and the finding may suggest potential therapeutic applications in enhancing hair regeneration.

A report on the use of a single intra-articular administration of autologous platelet therapy in a naturally occurring canine osteoarthritis model - a preliminary study

Background

Osteoarthritis (OA) represents a significant burden to societies, as it affects quality of life, performance and poses a large healthcare cost. We aimed to describe the use of a single intra-articular (IA) injection of an autologous platelet therapy in the management of osteoarthritis (OA) in a naturally occurring canine model.

Methods

Fifteen police working dogs with bilateral hip OA were treated with 3 ml of platelet concentrate per hip joint, produced with the V-PET kit. Response to treatment was measured by the Canine Brief Pain Inventory (CBPI, divided in pain interference score – PIS, and Pain Severity Score - PSS), Liverpool Osteoarthritis in Dogs (LOAD), Canine Orthopedic Index (COI, divided in four dimensions: function, gait, stiffness and quality of life - QOL) and the Hudson Visual Analogue Scale (HVAS). Seven different time points were considered: T0 (before treatment), T1 (after 15 days), T2, T3, T4, T5 and T6 (after 1, 2, 3, 4 and 5 months respectively). Results from each evaluation moment were compared with T0 with a Paired Samples T-Test, and a p < 0.05 was set.

Results

Significant differences were observed at T1 (p < 0.01 for HVAS, PSS, COI, Gait and QOL; p = 0.01 for PIS; p = 0.02 for Function; and p < 0.05 for Stiffness), T2 (p < 0.01 for PSS, PIS and Gait; p = 0.01 for COI; p = 0.02 for HVAS, Function and QOL; and p = 0.04 for Stiffness), T3 (p < 0.01 for HVAS, PSS, PIS, Function and Gait; p = 0.01 for COI; and p = 0.02 for QOL), T4 (p < 0.01 for PSS; p = 0.03 for PIS and Gait), T5 (p < 0.01 for COI, Function and Gait; p = 0.03 for PSS, PIS and Stiffness), T6 (p < 0.01 for PSS, Function and Gait; p = 0.04 for PIS; p < 0.05 for COI) and T7 (p < 0.01 for PSS, Function and Gait; p = 0.01 for COI; and p < 0.05 for PIS).

Conclusions

Autologous platelet therapy was used without apparent harm in the subjects. A single administration produced significant improvements, which lasted several months, and therefore warrants further study.

Use of autologous platelet-rich plasma in healing skin graft donor sites

Objective:

To demonstrate that the use of platelet-rich plasma (PRP) enhances both the quality of healing and the time required for wound healing at a skin graft donor site.

Methods:

Patients who had dermo-epidermal skin grafts taken from the thigh area were included in a prospective, randomised clinical study. PRP was applied to one donor site and then covered with Vaseline-impregnated, open-weave gauze and gauze, while the contralateral donor site on the other thigh served as a control and was covered with the open-weave gauze and gauze without PRP.

Results:

A total of 24 patients took part in the study, of which three developed infections and were thus removed from the study. Use of PRP reduced the wound healing time of the dermo-epidermal graft donor sites by a mean 17.8% and median 18 days. On average, the treated donor sites healed in 14.9 days compared with 18.4 days for the control group. The median was 14 days compared with 18 days in the control group (p=0.026). In one patient, healing was slower on the side where PRP was applied. In 20 patients, healing of the donor site was accelerated where PRP was applied.

Conclusion:

The study demonstrated a beneficial effect of PRP, as healing time was shortened. Using PRP to heal wounds could be beneficial for patients for whom commonly available wound healing therapies have failed, as well as for high-risk patient groups for whom problematic wound healing may be expected.

Platelet sonicates activate hair follicle stem cells and mediate enhanced hair follicle regeneration

An increasing number of studies show that platelet-rich plasma (PRP) is effective for androgenic alopecia (AGA). However, the underlying cellular and molecular mechanisms along with its effect on hair follicle stem cells are poorly understood. In this study, we designed to induce platelets in PRP to release factors by calcium chloride (PC) or by sonication where platelet lysates (PS) or the supernatants of platelet lysate (PSS) were used to evaluate their effect on the hair follicle activation and regeneration. We found that PSS and PS exhibited a superior effect in activating telogen hair follicles than PC. In addition, PSS injection into the skin activated quiescent hair follicles and induced K15⁺ hair follicle stem cell proliferation in K14-H2B-GFP mice. Moreover, PSS promoted skin-derived precursor (SKP) survival in vitro and enhanced hair follicle formation in vivo. In consistence, protein array analysis of different PRP preparations revealed that PSS contained higher levels of 16 growth factors (out of 41 factors analysed) than PC, many of them have been known to promote hair follicle regeneration. Thus, our data indicate that sonicated PRP promotes hair follicle stem cell activation and de novo hair follicle regeneration.

Efficacy of platelet-rich plasma for non-transfusion use: Overview of systematic reviews

INTRODUCTION

Platelet-rich plasma (PRP) is a blood component therapy with a supraphysiological concentration of platelets derived from allogenic or, more commonly, autologous blood. PRP has been used in different non-transfusion indications because of its role in the promotion of tissue repair and healing, in fields such as Traumatology, Dermatology and Dentistry.

OBJECTIVE

To provide a synthesis of the efficacy of PRP for different clinical situations.

METHODS

Systematic searches were carried out in MEDLINE, Embase, Cochrane Library and LILACS in July 2018 to identify systematic reviews (SRs) of randomized clinical trials (RCTs) focusing on PRP for non-transfusion use. Two authors independently screened all retrieved references in two stages (titles and abstracts at a first stage and full texts at a second stage). The methodological quality of SRs that met the eligibility criteria was appraised by AMSTAR 2. Conclusions were based on the most recent SRs with highest quality.

RESULTS

One thousand two hundred and forty references were retrieved. After checking the inclusion criteria, 29 SRs of RCTs related to three different fields (wound care, Orthopedics and Dentistry) were included. The results suggest the benefit of PRP for different clinical situations, such as diabetic wounds, acute lesions of musculoskeletal system, rotator cuff lesions, tendinopathies, knee and hip osteoarthritis, total knee arthroplasty, allogenic bone graft for dental implants and periodontal intrabony defects.

CONCLUSION

There is low to moderate quality evidence supporting the efficacy of PRP for specific clinical situations. The low quality of the evidence limits the certainty of these findings. Well-planned and well-conducted RCTs are still needed to further assess the efficacy of PRP.

The Current Status of Cell-Based Therapies for Primary Knee Osteoarthritis

There is a growing interest in cell therapy for knee osteoarthritis. This study systematically reviews the current status of cell-based therapies. The authors review treatment modalities, clinical outcomes, and the economics of cell therapy. Inclusion criteria were articles containing cellular therapy, platelet-rich plasma, and knee osteoarthritis in the title. Letters, editorial material, abstracts not published, and manuscripts with incomplete data were excluded. Forty-two articles met these inclusion criteria and were critically reviewed. Cell-based therapy holds promise as a means of restoring deficient local cartilage cell populations. There is no evidence-based information for the use of cell-based therapies in knee osteoarthritis.

Regenerative potential of platelets in patients with chronic kidney disease

INTRODUCTION

Chronic kidney disease (CKD) is a systemic disease affecting many organs. Progression of renal failure aggravates ongoing inflammation and increases oxidative stress. In the final stage of CKD, it is necessary to use renal replacement therapy. A side effect of dialysis therapy is the synthesis of proinflammatory factors and increased oxidative stress, which activates platelets and immune cells.

AIM OF THE STUDY

To determine the regenerative potential of platelets in patients with CKD based on the analysis of the relationships between substances with potential regenerative action, as well as analysis of the influence of the type of renal replacement therapy used on regeneration of platelets.

MATERIALS AND METHODS

The study group consisted of 117 patients. Based on the type of therapy used, patients were divided into four groups: hemodialysis, peritoneal dialysis, kidney transplant patients, and conservative treatment (30, 30, 27, and 30 patients). The control group consisted of 30 healthy volunteers. The concentrations of IGF-1, TGF-β, and PDGF-B in the blood serum were measured by ELISA methods.

RESULTS

It was shown that renal replacement therapy significantly influences the concentration of platelet growth factors (IGF-1: p = 0.025 and PDGF-B: p = 0.012). There was a relationship between the type of renal replacement therapy and the duration of dialysis, and the concentration of IGF-1, PDGF-B (p < 0.00001, p < 0.001).

CONCLUSIONS

The type of renal replacement therapy has a different effect on the concentration of platelet-derived growth factors IGF-1 and PDGF-B. PD patients had the highest concentrations of all growth factors, and this may be due to the presence of inflammation induced by dialysis-related advanced end-products of glycosylation (AGE).

In vitro effects of platelet-derived factors of brain glioma patients on C6 glioma cells

Platelets play an important part in the progression and pathological angiogenesis of brain glioma because of the different granules content and release of microvesicles that are the source of numerous mediators and bioactive substances, which probably provides a "strategy" for the tumour survival. The objective of study was exploring the effect of platelet-released secretion products of patients with brain glioma on the experimental model of tumour growth in vitro. For this purpose, the cells of glioma C6 were cultured for 72 hours under the addition of modified media containing platelet-released secretion products or conditioned media of peripheral blood cells of patients with glioma as well as persons of the comparison group without rough somatic pathology. In control glioma C6 cultures in standard conditions cell clusters were formed by the type of "spheroids", from which radial cell migration occurred, a tense cellular or reticular growth zone was formed, and tumour cells preserved their ability to mitotic division. Under the influence of platelet-released secretion products of patients with glioma, differently directed effects on cell mitotic activity and the number of cell clusters in glioma C6 cultures were detected depending on the degree of tumour malignancy: stimulating effect under the influence of platelet factors of patients with high-malignancy glioma (G4) and inhibitory effect – due to the influence of platelet factors of patients with differentiated glioma (G2). In contrast to the thrombocyte-released factors, the conditioned media of a common pool of peripheral blood cells of patients with G4 glioma suppressed the mitotic activity of tumour cells and did not affect the number of cell clusters. No changes in glioma C6 cultures were revealed after the influence of platelet-released secretion products of persons of the comparison group. The obtained data confirm the important role of platelets in the pathogenesis of brain glioma, pointing to the fundamental difference in the spectrum of biologically active molecules that are released by platelets of patients depending on the degree of tumour malignancy and are able to regulate the cell cycle and proliferative activity of the glioma tumour cells, which may have application as a diagnostic marker as well as predictive marker of response to antitumour therapy.

Efficacy of platelet-rich plasma in arthroscopic repair for discoid lateral meniscus tears

Background

To evaluate the clinical results of arthroscopic repair with or without platelet-rich plasma (PRP) for tears of the discoid lateral meniscus (DLM).

Methods

Twenty-nine patients with DLM tears within a stable knee were arthroscopically treated with meniscal suture repair. Of those, 14 were augmented with platelet-rich plasma (PRP), and 15 were performed without PRP augmentation. Patients were evaluated at baseline (the day before surgery) and then 12 and 24 months after the last injection. Evaluation included the Lysholm score, and Ikeuchi grade, Visual analogue score (VAS) for pain and failure rate. Failure was defined by patients developing symptoms of joint line pain, locking, swelling or requiring repeat arthroscopy.

Results

There was no difference in the failure rate in the PRP group (1 of 14) compared with the non-PRP group (2 of 15) (P = 0.58). Statistically significant improvement in Lysholm score, Ikeuchi grade and VAS for pain was documented at the last follow-up compared with baseline in both PRP and non-PRP group. No significantly difference was found between the PRP group and non-PRP group on Lysholm score, Ikeuchi grade and VAS for pain at the last follow-up. In the univariate analysis of each variable, younger age (P = 0.036) and longer follow-up duration (P = 0.043) were statistically associated with a better function improvement. Whereas in multivariate analysis, only younger age (P = 0.004) was significantly associated with a better function improvement.

Conclusion

With regard to clinical evaluations in arthroscopic repair for DLM tears, PRP group had similar effect in pain relief and functional improvement to non-PRP group at mid-term follow-up. Future larger prospective studies with a longer follow-up are needed to determine whether PRP should be used with DLM repair.

A Rare Case of Upper Calf Swelling and Necrosis - The Morel-Lavallée Lesion

A 31-year-old patient presented in the Emergency Department with a tibial fracture following a car accident that crushed the lower third of his thigh and the proximal and median part of his calf. Tibial fracture fixation with an intramedullary rod, was complicated by a Morel-Lavallée lesion. Sequential debridement procedures were performed with partially successful granulation tissue proliferation under NPWT (Negative-Pressure Wound Therapy). To further promote the already delaying granulation, plastic surgeons opted for PRP/PRF (Platelet Rich Plasma/Platelet Rich Fibrin) which allowed appropriate skin grafting. In our opinion, PRP/PRF should be considered as a viable adjuvant therapy to promote granulation.

Topic platelet gel application in chronic diabetic foot ulcers

In this observational study performed during 45 months we evaluated patients with chronic and recalcitrant diabetic ulcers who were treated with homologous platelet gel.

METHODS

platelet gels were obtained from homologous platelet concentrates that were aliquoted and freezed, being then activated with calcium gluconate and applied in the ulcer after cleaning and debridement. We evaluated patient's comorbidities, wound characteristics (size, tissue, inflammatory signs, pain), number and time of treatment as well as outcome (classified as complete epithelialization; partial improvement- 50% reduction in wound size or pain relief; no evolution).

RESULTS

Fifty-two patients (42 males, 10 females), with a median age of 65 years (range 43-85) were proposed for platelet gel. The following associated comorbidities were observed: hypertension (n = 41), dyslipidemia (n = 29), polyneuropathy (n = 30), peripheral arteriopathy (n = 32), retinopathy (n = 21), nephropathy (n = 15), cardiac ischemic disease (n = 14), obesity (n = 9). Thirty-eight patients presented with 3 or more associated comorbidities. The more frequent ulcer locations were sole of the foot (n = 13) and heel (n = 10). The median number of applications was 16, during 8.5 weeks. Nineteen patients (44%) achieved complete healing, 3 patients (7%) had a partial response and 21 (49%) had no progression. We did not observe a statistically significant relationship between patient age and response nor between number of comorbidities and response. We observed a more favorable evolution in patients with good compliance and good glycemic control.

CONCLUSION

Platelet gel is an effective therapeutic alternative, provided compliance and effective metabolic control are ensured.

Allograft Tissue Safety and Technology

Allograft tissues are commonly used by orthopedic surgeons and are processed using a variety of technologies to increase safety and clinical use. For safety, although disease transmission is a tangible risk, this possibility has been dramatically minimized through modern tissue-processing methods. These include steps to prevent processing tissues with unacceptable bioburden through rigorous screening using donor medical and social histories along with microbial testing of recovered tissue and viral testing of donor serum. Potential bioburden is also controlled through aseptic recovery and processing methods and then reduced through disinfection steps that can include antibiotics, detergents, mechanical process, chemical solutions, and terminal sterilization. Processing steps may also include decellularization methods to lower immunogenic potential of some tissues. To enhance fusion potential of bone void fillers, demineralization steps may be used, and the resultant demineralized bone matrices may be combined with a carrier to improve handling. Bone void fillers and osteochondral allografts may also be specially processed to retain a living cellular component. To preserve relevant biological, biochemical, and physical properties of allografts for clinical use and ease of handling, a number of methods may be used which include: (1) refrigeration in media, (2) freeze-drying, (3) cryopreservation, (4) freezing, and (5) media storage at room temperature. As academic and industry research continue to drive advances, the future direction of allograft tissue likely includes injectables, coatings, cellular therapies, and combinations with other materials. The technology approaches outlined here will be further described along with future directions.

Clinical Update: Why PRP Should Be Your First Choice for Injection Therapy in Treating Osteoarthritis of the Knee

PURPOSE OF REVIEW

The purpose of this review is to update the reader on the current applications of platelet-rich plasma (PRP) in the treatment of knee osteoarthritis (KOA). This review will focus on PRP's effect on the osteoarthritic joint, how PRP compares to traditional treatments of KOA, and provide clinical feedback on the use of PRP in an orthopedic and sports medicine practice.

RECENT FINDINGS

Recent research into the applications of PRP for KOA has further indicated both the efficacy and safety of PRP treatment. Although research has shown a tendency toward better efficacy at earlier stages of osteoarthritis (OA), evidence exists to indicate positive effects at all stages of OA. In summary, since KOA is an extremely prevalent condition that can be a challenge to treat, it is imperative that safe and effective nonoperative treatment methods be available to individuals that are suffering from this condition.

Is Platelet-Rich Plasma (PRP) Effective in the Treatment of Acute Muscle Injuries? A Systematic Review and Meta-Analysis

BACKGROUND

Muscle lesions account for one-third of sport-related injuries, thus representing a substantial problem for both players and their teams. The use of platelet-rich plasma (PRP) injections is rapidly growing in clinical practice, prompted by an unmet clinical need with a large commercial market. However, after early reports of positive preliminary experience, higher quality studies recently questioned the real benefit provided by PRP injections to promote muscle healing and return to sport.

OBJECTIVE

To evaluate the effect of platelet-rich plasma (PRP) injections on outcomes following acute muscle injuries.

DESIGN

Meta-analysis of randomized, controlled trials (RCTs), Level I.

DATA SOURCES

PubMed (MEDLINE), Cochrane (CENTRAL), Web of Science, clinicaltrials.gov, who.int, isrctn.com, greylit.org, opengrey.eu.

ELIGIBILITY CRITERIA

RCTs investigating the effect of PRP for the treatment of acute muscle injuries against at least one control group including patients treated with placebo injection or physical therapy. The outcomes evaluated were time to return to sport, re-injuries, complications, pain, muscle strength, range of motion (ROM)/flexibility, muscle function, and imaging.

RESULTS

Six studies, involving 374 patients, were included in the meta-analysis. The time to return to sport evaluated in all six studies was significantly shorter in patients treated with PRP (mean difference = - 7.17 days). However, if only the double-blind studies (n = 2) or studies including only hamstring injuries (n = 3) were considered, non-significant differences were found. Re-injuries (relative risk = - 0.03) and complications (relative risk = 0.01) were also similar between the two groups (p > 0.05), nor were any substantial differences found regarding pain, muscle strength, ROM/flexibility, muscle function, and imaging. The performance bias was high risk due to the lack of patient blinding in four studies. The quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) was therefore low or very low.

CONCLUSIONS

The promising biological rationale, the positive preclinical findings, and the successful early clinical experience of PRP injections are not confirmed by the recent high-level RCTs. Therefore any benefit in terms of pain, function, return to sport, and recurrence using PRP injections for the treatment of acute muscle injuries is not supported. Due to the bias in the studies, the heterogeneity of the findings, and the limited sample size, the evidence should be considered to be of low or very low quality.

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.

Treatment of Muscle Injuries with Platelet-Rich Plasma: a Review of the Literature

PURPOSE OF REVIEW

This review discusses the current literature regarding the use of platelet-rich plasma (PRP) in the treatment of muscle strain injuries. Case series as well as experimental trials for both human and animal models are covered.

RECENT FINDINGS

Multiple studies have examined outcomes for the use of PRP in the treatment of muscle strain injuries. PRP has been shown to promote muscle recovery via anabolic growth factors released from activated platelets, and in doing so, potentially reduces pain, swelling, and time for return to play. In vitro studies support the regenerative potential of PRP for acute soft tissue injuries. Multiple clinical case series for PRP injections in the setting of muscle strains demonstrate imaging evidence for faster healing, less swelling, which can decrease time for return to play. These studies, however, are retrospective in nature, and few randomized controlled studies exist to demonstrate a clear clinical benefit. Additionally, there is tremendous heterogeneity regarding the injectant preparation, optimum platelet concentration, presence of leukocytes, and volume of PRP which should be administered as well as number of and timing of treatments.

Effectiveness of platelet-rich plasma injection in patients with temporomandibular joint osteoarthritis: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The aim of this study was to investigate the effectiveness of platelet-rich plasma (PRP) injection after arthrocentesis or arthroscopy in patients with temporomandibular joint osteoarthritis.

STUDY DESIGN

Electronic databases (PubMed, EMBASE, Scopus, and Cochrane Library) were searched for reports up to July 30, 2018. We included all published or unpublished randomized controlled trials (RCTs). The primary outcome was pain reduction, and the secondary outcome was the improvement of maximal mouth opening. Weighted mean differences were utilized for random-effect meta-analysis.

RESULTS

Five RCTs were enrolled in the meta-analysis, comparing PRP injection to placebo (hyaluronic acid [HA] injection, saline injection, or no injection). The results revealed that PRP injection was more effective than placebo in pain reduction, but no in the improvement of maximal mouth opening, in the long term. In the subgroup analysis, PRP injection yielded better outcome only in pain reduction comparing to HA injection (Weighted mean difference 1.34, 95% confidence interval [CI] 0.95-1.73).

CONCLUSIONS

This meta-analysis demonstrated that PRP injection provided adjuvant efficacy to arthrocentesis or arthroscopy in pain reduction for temporomandibular joint osteoarthritis in the long term. Furthermore, PRP injection significantly reduced pain better compared with HA injection, saline injection, or no injection.

Fractal dimension in the evaluation of different treatments of muscular injury in rats

OBJECTIVES

To evaluate alterations from different therapies in muscular injury using the Fractal Dimension (FD) method.

METHODS

35 animals were allocated in Control Group (C), Injury Control Group (IC), Injury Low Level Laser Therapy Group (ILT), Injury Platelet Rich Plasma Group (IP), and Injury LLLT and PRP Group (ILP). The animals suffered a stretch injury in gastrocnemius muscle and after that IP and ILP groups received PRP application. The ILT and ILP groups received daily LLLT applications for seven days. After seven days the animals were euthanized and the gastrocnemius muscle removed and frozen. The muscles were stained with Hematoxylin and Eosin (HE) and Picrosirius Red, for observation of the morphology of the injury and semi-quantitative and quantitative analysis through the Fractal Dimension (FD) method.

RESULTS

In the qualitative and semi-quantitative analysis, in relation to IC group, the ILT presented a reduction in rounded fibers and the IP in angular fibers. The ILP group demonstrated a reduction in both polymorphic fibers and inflammatory infiltrate. The FD of the muscles stained with HE was higher in the groups that suffered the injury when compared to the C group (p < 0.05); the FD of the collagen demonstrated no statistical difference between the groups.

CONCLUSION

Both treatments were able to accelerate injury repair, and the association of both presented better results than the isolated applications. However, the FD method showed no sensitivity to differentiate the treatments, either in the histological aspects or the injury in collagen.

Partial Anterior Cruciate Ligament Ruptures: Advantages by Intraligament Autologous Conditioned Plasma Injection and Healing Response Technique-Midterm Outcome Evaluation

The historical treatment options for partial anterior cruciate ligament (ACL) ruptures were conservative therapy or ACL reconstruction by injured bundle or entire ACL replacement. In awareness of the regenerative potential of biologic agents such as mesenchymal stem cells or platelet rich plasma (PRP), the healing response technique was developed to preserve the injured ACL with better outcomes than the conservative therapy. Further improvement of this technique seems to be obtained by the additional application of PRP products. Thus, the aim of this study was to evaluate the midterm outcome after intraligament autologous conditioned plasma (ACP) by a clinical, scoring, and functional performance assessment. 42 patients were evaluated in this study. The failure rate was 9.5%. Outcome evaluation showed good to excellent results. The scores were IKDC subjective 83.2 (SD 14.5), Lysholm 85.5 (SD 15.5), Tegner 4.7 (SD 1.7), and Cincinnati 85.4 (SD 15.5) after a mean follow-up of 33 months. Clinical examination showed stable Lachman test, negative pivot shift phenomenon, and a significant reduction in AP-laxity compared to preoperative status (rolimeter preoperative: 1.9 (SD1.4); postoperative 0.6 (SD1.8), p=0.001) in all patients. Functional performance testing showed no significant differences between the injured and healthy side. Return to sport was achieved after a mean of 5.8 months (SD 3.6) in 71.1% of the included patients. In summary, this new treatment option revealed in midterm follow-up promising results to treat partial ACL lesions with a reduced need for conversion to ACL reconstruction and with a high percentage of return to preinjury sport activity.

Intra-articular platelet-rich plasma versus hyaluronic acid in the treatment of knee osteoarthritis: a meta-analysis

Purpose

Platelet-rich plasma (PRP) and hyaluronic acid (HA) have been increasingly used in recent years to treat knee osteoarthritis (OA). However, whether PRP is superior to HA is controversial.

Methods

We conducted an electronic search of PubMed, Embase, ScienceDirect, and Cochrane library. The pooled data were analyzed using RevMan 5.1.

Results

Three prospective and ten randomized trials were identified. PRP injections reduced pain more effectively than HA injections in OA of the knee at 6 months (mean difference [MD]=−14.18; 95% confidence interval [CI]: −26.12 to −2.23; P=0.02; I²=95%) and 12 months (MD=−15.25; 95% CI: −22.17 to −8.32; P<0.01; I²=81%) of follow-up evaluated by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score, while the VAS showed no significant difference at 3 months (MD=−0.98; 95% CI: −2.55 to 0.59; P=0.22; I²=90%) and 6 months (MD=−0.82; 95% CI: −1.80 to 0.16; P=0.1; I²=83%). Additionally, similar results were observed for the function recovery according to the WOMAC function score and EuroQol-visual analog scales.

Conclusion

The intra-articular injection of PRP was not obviously superior to HA in knee OA. Due to the limited quality and data of the evidence currently available, more high-quality randomized controlled trials are required.

The Utility of Biologics, Osteotomy, and Cartilage Restoration in the Knee

The management of complex cartilage and meniscal pathology in young, athletic patients is extremely challenging. Joint preservation surgery is most difficult in patients with concomitant knee pathologies, including cartilage defects, meniscal deficiency, malalignment, and/or ligamentous insufficiency. Clinical decision making for these patients is further complicated by articular cartilage lesions, which often are incidental findings; therefore, treatment decisions must be based on the confirmed contribution of articular cartilage lesions to symptomatology. Surgical management of any of the aforementioned knee pathologies that is performed in isolation typically results in acceptable patient outcomes; however, concomitant procedures for the management of concomitant knee pathologies often are essential to the success of any single procedure. The use of biologic therapy as an alternative to or to augment more conventional surgical management has increased in popularity in the past decade, and indications for biologic therapy continue to evolve. Orthopaedic surgeons should understand knee joint preservation techniques, including biologic and reconstructive approaches in young, high-demand patients.

Bone marrow concentrate and platelet-rich plasma differ in cell distribution and interleukin 1 receptor antagonist protein concentration

PURPOSE

Bone marrow concentrate (BMC) and platelet-rich plasma (PRP) are used extensively in regenerative medicine. The aim of this study was to determine differences in the cellular composition and cytokine concentrations of BMC and PRP and to compare two commercial BMC systems in the same patient cohort.

METHODS

Patients (29) undergoing orthopaedic surgery were enrolled. Bone marrow aspirate (BMA) was processed to generate BMC from two commercial systems (BMC-A and BMC-B). Blood was obtained to make PRP utilizing the same system as BMC-A. Bone marrow-derived samples were cultured to measure colony-forming units, and flow cytometry was performed to assess mesenchymal stem cell (MSC) markers. Cellular concentrations were assessed for all samples. Catabolic cytokines and growth factors important for cartilage repair were measured using multiplex ELISA.

RESULTS

Colony-forming units were increased in both BMCs compared to BMA (p < 0.0001). Surface markers were consistent with MSCs. Platelet counts were not significantly different between BMC-A and PRP, but there were differences in leucocyte concentrations. TGF-β1 and PDGF were not different between BMC-A and PRP. IL-1ra concentrations were greater (p = 0.0018) in BMC-A samples (13,432 pg/mL) than in PRP (588 pg/mL). The IL-1ra/IL-1β ratio in all BMC samples was above the value reported to inhibit IL-1β.

CONCLUSIONS

The bioactive factors examined in this study have differing clinical effects on musculoskeletal tissue. Differences in the cellular and cytokine composition between PRP and BMC and between BMC systems should be taken into consideration by the clinician when choosing a biologic for therapeutic application.

LEVEL OF EVIDENCE

Clinical, Level II.

Intra-articular platelet-rich plasma injections for knee osteoarthritis: An overview of systematic reviews and risk of bias considerations

OBJECTIVES

Numerous systematic reviews investigating the efficacy of platelet-rich plasma (PRP) in treating knee osteoarthritis (OA) have been recently published. The purpose of the present study was (1) to perform an overview of overlapping systematic reviews investigating PRP for knee OA via evaluating methodological quality and risk of bias of systematic reviews and (2) to provide recommendations through the best evidence.

METHODS

A systematic search of systematic reviews published through Feb 2017 was conducted using the MEDLINE, EMBASE and Cochrane Library. The methodological quality and risk of bias of included systematic reviews were assessed by AMSTAR instrument and ROBIS tool respectively. Best evidence choice procedure was conducted according to the Jadad decision algorithm. The systematic reviews with high quality of methodology and low risk of bias were selected ultimately.

RESULTS

Ten systematic reviews were eligible for inclusion. The Jadad decision making tool suggested that the reviews with highest AMSTAR score should be selected. According to the ROBIS tool, there were 4 systematic reviews with low risk of bias and 6 with high risk of bias. As a result, two systematic reviews conducted by Dai et al and Meheux et al with highest AMSTAR score and low risk of bias were selected as the best evidence.

CONCLUSIONS

The present overview demonstrates that PRP is an effective intervention in treating knee OA without increased risk of adverse events. Therefore, the present conclusions may help decision makers interpret and choose PRP with more confidence.

Conservative management of MRI-confirmed knee osteoarthritis with instrument-assisted soft-tissue mobilization, joint manipulation, and platelet-rich plasma

OBJECTIVE

To describe the successful conservative management of a patient with chronic degenerative knee pain.

CLINICAL FEATURES

An active 47 year-old female office-worker with intermittent right knee pain inferolateral to the right patella for eight months described difficulty ascending stairs, sitting on a chair for one hour, and squatting. A physical exam led to the diagnosis of a suspected chronic degenerative tear of the posterior horn of the right medial meniscus and chronic right subpatellar chondrosis, in addition to extensive cartilaginous degeneration revealed by an MRI study conducted prior to initial presentation.

INTERVENTION AND OUTCOME

A conservative chiropractic treatment plan was implemented in addition to two successive intra-articular and subpatellar platelet-rich plasma injections. The patient reported no pain after sixteen weeks and 93.75% functionality six months after the second injection.

Contributions for classification of platelet rich plasma - proposal of a new classification: MARSPILL

Platelet-rich plasma (PRP) has emerged as a significant therapy used in medical conditions with heterogeneous results. There are some important classifications to try to standardize the PRP procedure. The aim of this report is to describe PRP contents studying celular and molecular components, and also propose a new classification for PRP. The main focus is on mononuclear cells, which comprise progenitor cells and monocytes. In addition, there are important variables related to PRP application incorporated in this study, which are the harvest method, activation, red blood cells, number of spins, image guidance, leukocytes number and light activation. The other focus is the discussion about progenitor cells presence on peripherial blood which are interesting due to neovasculogenesis and proliferation. The function of monocytes (in tissue-macrophages) are discussed here and also its plasticity, a potential property for regenerative medicine treatments.

Histological analysis of the association of low level laser therapy and platelet-rich plasma in regeneration of muscle injury in rats

•

LLLT and PRP can be used to enhance muscle regeneration.

•

The association of LLLT with PRP produces better treatment than their use in isolation.

•

LLLT could modulate the production of collagen during muscle injury.

Objective

Muscle injuries are common, and their treatment requires costs and time off. Platelet rich plasma and low level laser therapy have been shown to be affordable and easy to use. The aim of this study was to evaluate the associated effects of low level laser therapy and platelet rich plasma on the treatment of the soleus muscle injured by strain in rats.

Methods

Thirty-five rats were randomly allocated into five groups: Control (C), Injury Control (IC), injury PRP (IP), injury LLLT (ILT) and injury LLLT and PRP (ILTP). The strain injury was induced in the soleus muscle and the IP group received application of platelet rich plasma immediately after the lesion, while the ILT group received low level laser therapy. After seven days, all animals were euthanized and the soleus muscle removed for further histological analysis.

Results

The association of both treatments (ILTP) resulted in better histological aspects than the low level laser therapy and platelet rich plasma alone, when compared with the injury group (IC). The collagen analysis exhibited a significant increase in the ILT group (2.99 SD = 1.13) compared to the C (1.88 SD = 0.41, p = 0.012) and IP (2.04 SD = 0.44, p = 0.018).

Conclusion

The association of low level laser therapy with platelet rich plasma produced better results on muscle injury compared to the isolated use of these therapies. Furthermore, none of the treatments could modulate the collagen deposition in relation to injury group.

Single Platelet-Rich Plasma Injection for Early Stage of Osteoarthritis of the Knee

Purpose  The purpose of this study was to determine the safety efficacy and outcomes of platelet-rich plasma (PRP) intra-articular injections for early stages of knee osteoarthritis (OA).

Methods  Twenty-five patients affected by grade I and II knee primary OA according to the Kellgren–Lawrence scale received a single intra-articular PRP injection. Patients were prospectively evaluated for 6 months. Visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee injury and Osteoarthritis Outcome Score (KOOS) scoring scales were used to evaluate clinical outcomes. Wilcoxon signed rank test was used to evaluate significance of improvement of WOMAC, KOOS, and VAS scores.

Results  Twenty-one patients completed 6-months follow-up. The median WOMAC score improved from 29.1 points (range: 17.4–60.4; standard deviation [SD] = 13.0) at baseline to 42.41 (range: 24.3–71.2; SD = 12.5) at final follow-up. Improvements in median KOOS and VAS score have been also found, from 37.49 points and 64.2 mm before injection to 59.71 points and 42.8 mm, respectively. All these improvements were statistically significant ( p  < 0.05). No adverse reactions have been observed.

Conclusion  Treating knee OA with PRP injection is safe. A single dose of PRP seems to be effective in managing pain and improving quality of life in patients with low-grade knee OA.

Level of Evidence  Level IV, therapeutic case series.

Biologic Approaches for the Treatment of Partial Tears of the Anterior Cruciate Ligament: A Current Concepts Review

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) has been established as the gold standard for treatment of complete ruptures of the anterior cruciate ligament (ACL) in active, symptomatic individuals. In contrast, treatment of partial tears of the ACL remains controversial. Biologically augmented ACL-repair techniques are expanding in an attempt to regenerate and improve healing and outcomes of both the native ACL and the reconstructed graft tissue.

PURPOSE

To review the biologic treatment options for partial tears of the ACL.

STUDY DESIGN

Review.

METHODS

A literature review was performed that included searches of PubMed, Medline, and Cochrane databases using the following keywords: partial tear of the ACL, ACL repair, bone marrow concentrate, growth factors/healing enhancement, platelet-rich plasma (PRP), stem cell therapy.

RESULTS

The use of novel biologic ACL repair techniques, including growth factors, PRP, stem cells, and bioscaffolds, have been reported to result in promising preclinical and short-term clinical outcomes.

CONCLUSION

The potential benefits of these biological augmentation approaches for partial ACL tears are improved healing, better proprioception, and a faster return to sport and activities of daily living when compared with standard reconstruction procedures. However, long-term studies with larger cohorts of patients and with technique validation are necessary to assess the real effect of these approaches.

Ultrasound biomicroscopy and claudication test for in vivo follow-up of muscle repair enhancement based on platelet-rich plasma therapy in a rat model of gastrocnemius laceration

PURPOSE

To track the regeneration process of lateral gastrocnemius due to a muscle laceration in rats, and to treatment with plateletrich plasma (PRP).

METHODS

Ultrasound (40 MHz) images were used for measuring pennation angle (PA), muscle thickness (MT) and mean pixel intensity, along with claudication scores, of treated (PRPG) and non-treated (NTG) groups of rats.

RESULTS

NTG showed a PA increase for the non-injured leg (p<0.05) and a tendency of MT to increase, whereas for PRPG there were no differences. There was a progressive reduction of the claudication score for the PRPG group throughout the entire period, with an immediate difference after seven days (p<0.05), whereas the NTG had a significant reduction only at day 28 (p<0.05).

CONCLUSION

It was observed a compensatory hypertrophic response due to the overload condition imposed to healthy leg for NTG that did not occur in PRPG, suggesting an accelerated repair process of the injured leg due to treatment, anticipating its use.

Therapeutics for tendon regeneration: a multidisciplinary review of tendon research for improved healing

Tendon injuries, known as tendinopathies, are common musculoskeletal injuries that affect a wide range of the population. Canonical tendon healing is characterized by fibrosis, scar formation, and the loss of tissue mechanical and structural properties. Understanding the regenerative tendon environment is an area of increasing interest in the field of musculoskeletal research. Previous studies have focused on utilizing individual elements from the fields of biomechanics, developmental biology, cell and growth factor therapy, and tissue engineering in an attempt to develop regenerative tendon therapeutics. Still, the specific mechanism for regenerative healing remains unknown. In this review, we highlight some of the current approaches of tendon therapeutics and elucidate the differences along the tendon midsubstance and enthesis, exhibiting the necessity of location-specific tendon therapeutics. Furthermore, we emphasize the necessity of further interdisciplinary research in order to reach the desired goal of fully understanding the mechanisms underlying regenerative healing.

Intra-articular Autologous Conditioned Plasma Injections Provide Safe and Efficacious Treatment for Knee Osteoarthritis: An FDA-Sanctioned, Randomized, Double-blind, Placebo-controlled Clinical Trial

BACKGROUND

Platelet-rich plasma (PRP) injections have become an intriguing treatment option for osteoarthritis (OA), particularly OA of the knee. Despite the plethora of PRP-related citations, there is a paucity of high-level evidence that is comparable, cohort specific, dose controlled, injection protocol controlled, and double-blinded.

PURPOSE

To determine the safety and efficacy of leukocyte-poor PRP autologous conditioned plasma (ACP) for knee OA treatment through a feasibility trial regulated by the US Food and Drug Administration (FDA).

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

In accordance with FDA protocol, patient selection was based on strict inclusion/exclusion criteria; 114 patients were screened, and 30 were ultimately included in the study. These patients were randomized to receive either ACP (n = 15) or saline placebo (n = 15) for a series of 3 weekly injections. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores served as the primary efficacy outcome measure. Patients were followed for 1 year.

RESULTS

No adverse events were reported for ACP administration. Furthermore, the results demonstrated no statistically significant difference in baseline WOMAC scores between the 2 groups. However, in the ACP group, WOMAC scores at 1 week were significantly decreased compared with baseline scores, and the scores for this group remained significantly lower throughout the study duration. At the study conclusion (12 months), subjects in the ACP group had improved their overall WOMAC scores by 78% from their baseline score, compared with 7% for the placebo group.

CONCLUSION

ACP is safe and provides quantifiable benefits for pain relief and functional improvement with regard to knee OA. No adverse events were reported for ACP administration. After 1 year, WOMAC scores for the ACP subjects had improved by 78% from their baseline score, whereas scores for the placebo control group had improved by only 7%. Other joints affected with OA may also benefit from this treatment.

Ultrasound-Guided Injection of Platelet-Rich Plasma and Hyaluronic Acid, Separately and in Combination, for Hip Osteoarthritis: A Randomized Controlled Study

BACKGROUND

The effectiveness of intra-articular platelet-rich plasma (PRP) injections has been evaluated in knee chondroplasty and osteoarthritis (OA); however, little evidence of its efficacy in hip OA exists.

PURPOSE

To compare the therapeutic efficacy of autologous PRP, hyaluronic acid (HA), or a combination of both (PRP+HA) in hip OA.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Patients aged between 18 and 65 years who were treated with outpatient surgery and who had hip OA and pain intensity at baseline of >20 on a 100-mm visual analog scale (VAS) were recruited for this study. Exclusion criteria were extensive surgery; presence of excessive deformities; or rheumatic, infective, cardiovascular, or immune system disorders. The primary outcome measure was a change in pain intensity as assessed by the VAS at 2, 6, and 12 months after treatment. Secondary outcome measures were the Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and concentration of growth factors in PRP and their correlation with clinical outcomes. Clinical outcomes were evaluated by assessors and collectors blinded to the type of treatment administered.

RESULTS

A total of 111 patients were randomly assigned to 3 groups and received 3 weekly injections of either PRP (44 patients), PRP+HA (31 patients), or HA (36 patients). At all follow-ups, the PRP group had the lowest VAS scores. In particular, at 6-month follow-up, the mean VAS score was 21 (95% CI, 15-28) in the PRP group, 35 (95% CI, 26-45) in the PRP+HA group, and 44 (95% CI, 36-52) in the HA group (P < .0005 [PRP vs HA] and P = .007 [PRP vs PRP+HA]; F = 0.663). The WOMAC score of the PRP group was significantly better at 2-month follow-up (mean, 73; 95% CI, 68-78) and 6-month follow-up (mean, 72; 95% CI, 67-76) but not at 12-month follow-up. A significant, "moderate" correlation was found between interleukin-10 and variations of the VAS score (r = 0.392; P = .040). Significant improvements were achieved in reducing pain and ameliorating quality of life and functional recovery.

CONCLUSION

Results indicated that intra-articular PRP injections offer a significant clinical improvement in patients with hip OA without relevant side effects. The benefit was significantly more stable up to 12 months as compared with the other tested treatments. The addition of PRP+HA did not lead to a significant improvement in pain symptoms.

A Pilot Study Evaluating the Effectiveness of Platelet-Rich Plasma Therapy for Treating Degenerative Tendinopathies: A Randomized Control Trial with Synchronous Observational Cohort

Objective

This pilot study aimed to inform future research evaluating the effectiveness of Platelet Rich Plasma (PRP) injection for tendinopathy.

Design

Randomized control trial (RCT) and synchronous observational cohort studies. For the RCT, consecutive consenting patients treated at an academic sports medicine clinic were randomly assigned to either a PRP or placebo control group.

Setting

The Glen Sather Sport Medicine Clinic, Edmonton, Canada.

Patients

The RCT included 9 participants with rotator cuff tendinopathy. The cohort study included 178 participants with a variety of tendinopathies.

Interventions

Patients receiving PRP were injected with 4 ml of platelets into the supraspinatus and/or infraspinatus, while patients in the placebo group were injected with 4ml of saline. All participants undertook a 3-month standardized, home-based, daily exercise program.

Main Outcome Measures

Participants in the RCT were re-evaluated 3, and 6 months post-injection. Change scores before and after injection on pain, disability and MRI-documented pathology outcomes were compared. In the cohort study, pain and disability were measured at 1, 2 and 3 months post-injection.

Results

For the RCT, 7 participants received PRP and 2 received placebo injections. Patients receiving PRP reported clinically important improvements in pain (>1.5/10 on VAS), disability (>15 point DASH change), and tendon pathology while those receiving placebo injections did not. In the observational cohort, statistically and clinically significant improvements in pain and disability were observed.

Conclusion

This pilot study provides information for planning future studies of PRP effectiveness. Preliminary results indicate intratendinous, ultrasound-guided PRP injection may lead to improvements in pain, function, and MRI-documented tendon pathology.

Trial Registration

Controlled-Trials.com ISRCTN68341698

Hamstrings anterior cruciate ligament reconstruction with and without platelet rich fibrin matrix

PURPOSE

Anterior cruciate ligament (ACL) rupture is the most common complete ligamentous injury in the knee. Many studies explored ACL graft integration and maturation, but only a few assessed the application of platelet rich fibrin matrix (PRFM) as augmentation for ACL reconstruction. The main aim of this study was to test the PRFM augmentation in terms of graft-bone integration and knee stability. The secondary aim was to investigate patient-reported functional status.

METHODS

Prospective evaluation has been done in two consecutive series of patients who underwent ACL reconstruction with semitendinosus and gracilis (STG) grafts: 14 patients were operated with PRFM augmentation and 14 patients without PRFM augmentation. Objective clinical evaluation (Rolimeter) and MRI evaluation were performed at 1 year from surgery. Subjective evaluation (IKDC) was performed pre-operatively and at 6 months, 1 and 2 years from surgery.

RESULTS

A statistically significant difference was not detected between the two groups in terms of MRI and objective clinical evaluation, although PRFM-augmented patients showed a statistically significant higher clinical improvement.

CONCLUSIONS

The procedure described for PRFM augmentation in ACL STG reconstruction does not improve radiologic graft integration and knee stability after 1 year and should not be used by clinicians to this purpose. However, it may result in a short-term improvement of patient-reported knee function, and future research should focus on further developing PRP treatment to optimize ACL clinical outcome.

LEVEL OF EVIDENCE

III.

Does Intra-articular Platelet-Rich Plasma Injection Provide Clinically Superior Outcomes Compared With Other Therapies in the Treatment of Knee Osteoarthritis? A Systematic Review of Overlapping Meta-analyses

PURPOSE

The aims of this study were (1) to perform a systematic review of meta-analyses evaluating platelet-rich plasma (PRP) injection in the treatment of knee joint cartilage degenerative pathology, (2) to provide a framework for analysis and interpretation of the best available evidence to provide recommendations for use (or lack thereof) of PRP in the setting of knee osteoarthritis (OA), and (3) to identify literature gaps where continued investigation would be suggested.

METHODS

Literature searches were performed for meta-analyses examining use of PRP versus corticosteroids, hyaluronic acid, oral nonsteroidal anti-inflammatory drugs, or placebo. Clinical data were extracted, and meta-analysis quality was assessed. The Jadad algorithm was applied to determine meta-analyses that provided the highest level of evidence.

RESULTS

Three meta-analyses met the eligibility criteria and ranged in quality from Level II to Level IV evidence. All studies compared outcomes of treatment with intra-articular platelet-rich plasma (IA-PRP) versus control (intra-articular hyaluronic acid or intra-articular placebo). Use of PRP led to significant improvements in patient outcomes at 6 months after injection, and these improvements were seen starting at 2 months and were maintained for up to 12 months. It is unclear if the use of multiple PRP injections, the double-spinning technique, or activating agents leads to better outcomes. Patients with less radiographic evidence of arthritis benefit more from PRP treatment. The use of multiple PRP injections may increase the risk of self-limited local adverse reactions. After application of the Jadad algorithm, 3 concordant high-quality meta-analyses were selected and all showed that IA-PRP provided clinically relevant improvements in pain and function compared with the control treatment.

CONCLUSIONS

IA-PRP is a viable treatment for knee OA and has the potential to lead to symptomatic relief for up to 12 months. There appears to be an increased risk of local adverse reactions after multiple PRP injections. IA-PRP offers better symptomatic relief to patients with early knee degenerative changes, and its use should be considered in patients with knee OA.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II through IV studies.