The use of platelet-rich fibrin with platelet-rich plasma support meniscal repair surgery

[Short-term effectiveness of transtibial pull-out technique for complete radial tear of lateral meniscus body]

Objective

To investigate the short-term effectiveness of transtibial pull-out technique combined with side-to-side suture technique in treatment of complete radial tear of lateral meniscus body.

Methods

Between May 2020 and August 2023, 15 patients with complete radial tear of lateral meniscus body were repaired by arthroscopic transtibial pull-out technique combined with side-to-side suture technique. There were 11 males and 4 females, with an average age of 25.2 years (range, 15-43 years). Twelve cases were acute injuries and 3 were chronic injuries. All patients had tenderness in the lateral compartment of the knee. No abnormal alignment was observed on the X-ray films of the knee. MRI showed the complete radial tear of lateral meniscus body without associated injuries such as anterior cruciate ligament or cartilage. Preoperative Lysholm score was 44.5±6.4, International Knee Documentation Committee (IKDC) subjective score was 40.2±8.4, Tegner score was 1.3±1.1, and visual analogue scale (VAS) score for pain was 5.1±1.1. The operation time, incision healing, and complications such as vascular/nerve injury were recorded. During follow-up, the range of motion of the knee and tenderness in the lateral compartment of the knee were observed. The knee function and pain were evaluated using Lysholm score, Tegner score, IKDC subjective score, and VAS score. X-ray films and MRI of the knee were reexamined to assess knee degeneration.

Results

The operation time was 60-145 minutes (mean, 89.6 minutes). All incisions healed by first intention, and no complication such as vascular/nerve injury occurred. All patients were followed up 17-56 months (mean, 38.4 months). All patients had no knee extension limitation and 3 cases had tenderness in the lateral compartment of the knee. At last follow-up, the Lysholm score, IKDC subjective score, Tegner score, and VAS score for pain were 85.3±7.8, 82.1±15.7, 4.7±1.2, and 1.5±1.0, respectively, which were superior to those before operation ( P<0.05). Imaging reexamination showed that the meniscus was reset at 1 day after operation, and there was no sign of knee degeneration at last follow-up.

Conclusion

Transtibial pull-out technique combined with side-to-side suture technique can effectively treat the complete radial tear of lateral meniscus body and obtain good short-term effectiveness.

Advances in meniscus tissue engineering: Towards bridging the gaps from bench to bedside

Meniscus is vital for maintaining the anatomical and functional integrity of knee. Injuries to meniscus, commonly caused by trauma or degenerative processes, can result in knee joint dysfunction and secondary osteoarthritis, while current conservative and surgical interventions for meniscus injuries bear suboptimal outcomes. In the past decade, there has been a significant focus on advancing meniscus tissue engineering, encompassing isolated scaffold strategies, biological augmentation, physical stimulus, and meniscus organoids, to improve the prognosis of meniscus injuries. Despite noteworthy promising preclinical results, translational gaps and inconsistencies in the therapeutic efficiency between preclinical and clinical studies exist. This review comprehensively outlines the developments in meniscus tissue engineering over the past decade (Scheme 1). Reasons for the discordant results between preclinical and clinical trials, as well as potential strategies to expedite the translation of bench-to-bedside approaches are analyzed and discussed.

How to Improve Meniscal Repair through Biological Augmentation: A Narrative Review

Since the role of the menisci in knee stability, proprioception, and homeostasis has been well established, significant efforts have been made to repair meniscal tears, resulting in excellent clinical outcomes and a reduction in the progression of knee osteoarthritis (OA). However, varying failure rates have been reported, raising questions regarding the healing potential in cases of complex injuries, poorly vascularized and degenerated areas, and generally in the presence of unfavorable biological characteristics. Therefore, over the last few decades, different strategies have been described to increase the chances of meniscal healing. Biological augmentation of meniscal repair through various techniques represents a safe and effective strategy with proven clinical benefits. This approach could reduce the failure rate and expand the indications for meniscal repair. In the present study, we thoroughly reviewed the available evidence on meniscal repair surgery and summarized the main techniques that can be employed to enhance the biological healing potential of a meniscal lesion. Our aim was to provide an overview of the state of the art on meniscal repair and suggest the best techniques to reduce their failure rate.

Biologic Augmentation of Isolated Meniscal Repair

PURPOSE OF REVIEW

The limited blood supply and intrinsic healing capacity of the meniscus contributes to suboptimal tissue regeneration following injury and surgical repair. Biologic augmentation techniques have been utilized in combination with isolated meniscal repair to improve tissue regeneration. Several innovative strategies such as Platelet-Rich Plasma (PRP), fibrin clots, mesenchymal stem cells (MSCs), bone marrow stimulation, meniscal scaffolds, and meniscal wrapping, are being explored to enhance repair outcomes. This article provides a comprehensive review of recent findings and conclusions regarding biologic augmentation techniques.

RECENT FINDINGS

Studies on PRP reveal mixed outcomes, with some suggesting benefits in reducing failure rates of isolated meniscal repair, while others question its efficacy. Fibrin clots and PRF (Platelet-rich fibrin), although promising, show inconsistent results and lack sufficient evidence for definitive conclusions. MSCs demonstrate potential in preclinical studies, but clinical trials have been limited and inconclusive. Bone marrow stimulation appears effective in certain contexts, but its broader applicability remains uncertain. Meniscal scaffolds, including CMI (Collagen Meniscal Implants) and Actifit (polyurethane scaffolds), show encouraging short- and mid-term outcomes but have not consistently surpassed traditional methods in the long term. Meniscal wrapping is infrequently studied but demonstrates positive short-term results with certain applications. The review reveals a diverse range of outcomes for biologic augmentation in meniscal repair. While certain techniques show promise, particularly in specific scenarios, the overall efficacy of these methods has yet to reach a consensus. The review underscores the necessity for standardized, high-quality research to establish the definitive effectiveness of these biologic augmentation methods.

Effects of the multiscale porosity of decellularized platelet-rich fibrin-loaded zinc-doped magnesium phosphate scaffolds in bone regeneration

In recent years, metallic ion-doped magnesium phosphate (MgP)-based degradable bioceramics have emerged as alternative bone substitute materials owing to their excellent biocompatibility, bone-forming ability, bioactivity, and controlled degradability. Conversely, incorporating a biomolecule such as decellularized platelet-rich fibrin (d-PRF) on scaffolds has certain advantages for bone tissue regeneration, particularly in enhanced osteogenesis and angiogenesis. The present study focuses on the impact of d-PRF-loaded multiscale porous zinc-doped magnesium phosphate (Zn-MgP) scaffolds on biodegradability, biocompatibility, and bone regeneration. Scaffolds were fabricated through the powder-metallurgy route utilizing naphthalene as a porogen (porosity = 5-43%). With the inclusion of a higher porogen, a higher fraction of macro-porosity (>20 μm) and pore interconnectivity were observed. X-ray diffraction (XRD) studies confirmed the formation of the farringtonite phase. The developed scaffolds exhibited a minimum ultimate compressive strength (UCS) of 8.5 MPa (for 40 Naph), which lies within the range of UCS of the cancellous bone of humans (2-12 MPa). The in vitro assessment via immersion in physiological fluid yielded a higher deposition of the calcium phosphate (CaP) compound in response to increased macro-porosity and interconnectivity (40 Naph). Cytocompatibility assessed using MC3T3-E1 cells showed that the incorporation of d-PRF coupled with increased porosity resulted the highest cell attachment, proliferation, and viability. For further evaluation, the developed scaffolds were implanted in in vivo rabbit femur condylar defects. Radiography, SEM, OTC labelling, and histology analysis after 2 months of implantation revealed the better invasion of mature osteoblastic cells into the scaffolds with enhanced angiogenesis and superior and accelerated healing of bone defects in d-PRF-incorporated higher porosity scaffolds (40 Naph). Finally, it is hypothesized that the combination of d-PRF incorporation with multiscale porosity and increased interconnectivity facilitated better bone-forming ability, good biocompatibility, and controlled degradability within and around the Zn-doped MgP scaffolds.

Usefulness of platelet-rich fibrin as a scaffold for meniscal repair: A non-randomized controlled cohort/follow-up study

Background

Although regenerative medicine treatment is still in its infancy in Japan, legislation within the past decade has provided opportunities to explore new treatment methods using regenerative medicine. We conducted a 2-year prospective follow-up study to statistically analyze treatment outcomes using platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) as effective scaffolds in meniscal repair.Questions/Purposes.1. Does the use of PRF and PRP for meniscal repair surgery regenerate the meniscus?2. Does augmentation of meniscal repair with PRF effectively improve knee function outcomes?

Methods

Thirty-five patients underwent arthroscopic meniscal repair with PRP and PRF using new devices with all-inside techniques. Among these, 31 patients were evaluated for clinical outcomes postoperatively, and magnetic resonance imaging (MRI) findings were evaluated. The variables were coded appropriately by creating a new column based on the Kellgren-Lawrence classification over time. Log transformation of different time points (pre, post 6, 12, or 24 months) in relation to Lysholm, International Knee Documentation Committee (IKDC), Japanese Orthopedic Association (JOA), and Tegner scores were performed. Follow-up arthroscopy using a needle scope was performed in some cases 2 years later. The PRP and PRF used were characterized using the Minimum Information for Studies Evaluating Biologics in Orthopaedics classification.

Results

Overall, 31 patients were evaluated (mean age = 39.1 ± 15.7 years; preoperative rehabilitation period = 9.5 ± 7.7 weeks). The PRP had mean platelet and white blood cell concentrations of approximately 5.5- and 3.6-fold, respectively. A significant association existed between sex and deformity deterioration but not in age between the two groups classified by deformity deterioration. Surgical intervention significantly and positively impacted knee function, although no significant changes were found in the activity of the participants over time. MRI findings showed no regeneration of the repaired meniscus; nevertheless, none of them worsened. Furthermore, a case where the traumatic cartilage defect was covered with fibrocartilage-like tissue as a secondary finding was observed.

Conclusions

Meniscal repair surgery using PRP/PRF is an effective treatment option for improving knee function in patients with knee deformity.

Level of evidence

Level III, Non-randomized controlled cohort/follow-up study.

Utility of Platelet-Rich Plasma Therapy in the Management of Meniscus Injuries: A narrative review

Menisci are crucial for knee joint functions and meniscal tears are common injuries, especially in sports activities. Platelet-rich plasma (PRP), which enhances healing, has emerged as a promising additive treatment for meniscus injuries, utilizing the regenerative properties of platelets and growth factors for improved clinical outcomes. In studies with a follow-up period of less than one year, the use of platelet-rich plasma (PRP) therapy for meniscus injuries showed significant improvements in knee symptoms and daily activity. Patients experienced enhanced outcomes in terms of pain reduction and increased sports activity, with MRI scans indicating stable meniscus conditions after six months. Studies with a follow-up of more than one year, however, did not find significant differences between groups treated with PRP and groups not treated with PRP in terms of various outcome measures, including pain and knee function. The vascularization of the menisci is vital for their proper function, and insufficient blood supply can affect healing of meniscal injuries. PRP therapy is used to enhance meniscal healing by introducing growth factors and anti-inflammatory agents. PRP therapy may enable athletes with meniscal tears to return to sports more quickly and has less rehabilitation duration. While PRP seems promising as an alternative to failed treatment or as an adjunct to treatment in the short term, its long-term effectiveness remains inconclusive. Patient preferences, commitment to therapy rehabilitation, and cost should all be considered on an individual basis.

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.

Use of Injectable Platelet-Rich Fibrin Accompanied by Bone Graft in Socket Endurance: A Radiographic and Histological Study

Background Ridge preservation became a crucial dental health issue and strategy to keep away from ridge defacement after post-tooth loss. The recent scientific evolution of platelet-rich fibrin (PRF) comprises a parenteral formulation of PRF. The combined allograft for socket preservation gives benefits. In this study, bone allografts, demineralized freeze-dried bone allografts (DFDBA) and freeze-dried bone allografts (FDBA) are used in a 30:70 ratio alone or in combination with injectable PRF (I-PRF) for socket preservation. Methods This study is a radiographic and histological examination conducted on 60 participants aged between 19-65 years. Participating patients agreed voluntarily that they would not bear any fixed prosthesis for the next nine months and plan for implanted teeth placement, including multi-rooted mandibular molars denticles. Both groups received atraumatic extraction; then, the socket was preserved with bone allograft alone in the control group and bone allograft mixed with I-PRF, forming sticky bone, in the experimental group. Clinical, radiological, and histological assessments were taken at the inception stage, three months, six months, and nine months. A multivariate regression model and a generalized estimating equation (GEE) model were used to analyse the effects of these changes on outcomes. Results In all the parameters, the test group indicated a good amount of bone growth with increasing intervals of time for bone height radiographically with statistically significant difference present (p<0.05) and histologically after nine months when socket site grafted with bone graft in combination with I-PRF. Conclusion This study's results demonstrated that I-PRF possesses the potential to regenerate and heal in the tooth-extracted socket. This study further recommends the implementation of I-PRF in safeguarding and conserving the raised rim of the tooth. Future research should take place on the osteogenic capability of I-PRF in more comprehensive ridge accession surgical procedures and additional expanding and improving capacities in periodontal reconstruction.

Fibrin clot and Leukocyte-rich platelet-rich fibrin show similar release kinetics and amount of growth factors: a pilot study

BACKGROUND

In knee arthroscopic surgery, fibrin clot (FC) and leukocyte-rich platelet-rich fibrin (L-PRF) may be used in augmentation for meniscal repair. Studies have investigated growth factors released from FC and L-PRF; however, it is difficult to compare FC and L-PRF between different studies. Direct comparison of growth factors that may support meniscal healing released from FC and L-PRF may be beneficial in deciding whether to use FC or L-PRF. If no significant difference is seen, the surgeon may decide to use FC which is easier to prepare compared to L-PRF. The purpose of this pilot study is to investigate the release amount and pattern of basic fibroblast growth factor (bFGF), platelet-derived growth factor AB (PDGF-AB), transforming growth factor β1 (TGF-β1), vascular endothelial growth factor (VEGF), and stromal cell-derived factor 1 (SDF-1) from FC and L-PRF.

METHOD

Twenty milliliters (ml) of whole blood was collected from each of the four volunteers. Ten milliliters of whole blood was allocated for preparation of FC and 10 ml for L-PRF. FC and L-PRF were separately placed in 5 ml of culture media. Five milliliters of the culture media was sampled and refilled at 15 min, 1 day, 3 days, 1 week and 2 weeks. The collected culture was used to quantify bFGF, PDGF-AB, TGF-β1, VEGF, and SDF-1 release by Enzyme-linked immune-sorbent assay (ELISA). Mann-Whitney U test was performed to assess significance of differences in amount of each growth factor released between FC and L-PRF. Significance was accepted at P value less than 0.05.

RESULTS

At two weeks, the cumulative release of TGF-β1 was the highest among all the growth factors in both FC and L-PRF (FC:19,738.21 pg/ml, L-PRF: 16,229.79 pg/ml). PDGF-AB (FC: 2328 pg/ml, L-PRF 1513.57 pg/ml) had the second largest amount, followed by VEGF (FC: 702.06 pg/ml, L-PRF 595.99 pg/ml) and bFGF (FC: 23.48 pg/ml, L-PRF 18.2 pg/ml), which order was also common in both FC and L-PRF. No significant difference in final release amount and pattern was seen between FC and L-PRF.

CONCLUSION

The current pilot study showed that cumulative release amount and release pattern of PDGF-AB, VEGF, TGF-β1, and bFGF did not significantly differ between FC and L-PRF during the two weeks of observation.

Controlled release of protein from gelatin/chitosan hydrogel containing platelet-rich fibrin encapsulated in chitosan nanoparticles for accelerated wound healing in an animal model

The physiological healing process is disrupted in many cases using the current wound healing procedures, resulting in delayed wound healing. Hydrogel wound dressings provide a moist environment to enhance granulation tissue and epithelium formation in the wound area. However, exudate accumulation, bacterial proliferation, and reduced levels of growth factors are difficulties of hydrogel dressings. Here, we loaded platelet-rich fibrin-chitosan (CH-PRF) nanoparticles into the gelatin-chitosan hydrogel (Gel-CH/CH-PRF) by solvent mixing method. Our goal was to evaluate the characteristics of hydrogel dressings, sustained release of proteins from the hydrogel dressing containing PRF, and reduction in the risk of infection by the bacteria in the wound area. The Gel-CH/CH-PRF hydrogel showed excellent swelling behavior, good porosity, proper specific surface area, high absorption of wound exudates, and proper vapor permeability rate (2023 g/m ².day), which provided requisite moisture without dehydration around the wound area. Thermal behavior and the protein release from the hydrogels were investigated using simultaneous thermal analysis and the Bradford test, respectively. Most importantly, an excellent ability to control the release of proteins from the hydrogel dressings was observed. The high antimicrobial activity of hydrogel was confirmed using Gram-positive and Gram-negative bacteria. Due to the presence of chitosan in the hydrogels, the lowest scavenging capacity-50 value (5.82 μgmL^-1) and the highest DPPH radical scavenging activity (83 %) at a concentration 25 μgmL^-1 for Gel-CH/CH-PRF hydrogel were observed. Also, the hydrogels revealed excellent cell viability and proliferation. The wound healing process was studied using an in vivo model of the full-thickness wound. The wound closure was significantly higher on Gel-CH/CH-PRF hydrogel compared to the control group, indicating the highest epidermis thickness, and enhancing the formation of new granulation tissue. Our findings demonstrated that Gel-CH/CH-PRF hydrogel can provide an ideal wound dressing for accelerated wound healing.

Applications and prospects of different functional hydrogels in meniscus repair

The meniscus is a kind of fibrous cartilage structure that serves as a cushion in the knee joint to alleviate the mechanical load. It is commonly injured, but it cannot heal spontaneously. Traditional meniscectomy is not currently recommended as this treatment tends to cause osteoarthritis. Due to their good biocompatibility and versatile regulation, hydrogels are emerging biomaterials in tissue engineering. Hydrogels are excellent candidates in meniscus rehabilitation and regeneration because they are fine-tunable, easily modified, and capable of delivering exogenous drugs, cells, proteins, and cytokines. Various hydrogels have been reported to work well in meniscus-damaged animals, but few hydrogels are effective in the clinic, indicating that hydrogels possess many overlooked problems. In this review, we summarize the applications and problems of hydrogels in extrinsic substance delivery, meniscus rehabilitation, and meniscus regeneration. This study will provide theoretical guidance for new therapeutic strategies for meniscus repair.

Platelet-rich plasma use in meniscus repair treatment: a systematic review and meta-analysis of clinical studies

Background

There is conflicting clinical evidence whether platelet-rich plasma (PRP) therapies could translate to an increased meniscus healing rate and improved functional outcomes. The objective of this systematic review and meta-analysis was to compare the failure rate and patient-reported functional outcomes in meniscus repair augmented with and without PRP.

Methods

We comprehensively searched the PubMed, Web of Science, Medline, Embase, and Cochrane Library databases to identify studies that compared the clinical efficacy of meniscus repair performed with PRP versus without PRP. The primary outcome was the meniscus repair failure rate, while the secondary outcomes were knee-specific patient-reported outcomes, including the International Knee Documentation Committee (IKDC) score, Lysholm knee scale, visual analog scale, Tegner activity level score, Western Ontario and McMaster Universities Osteoarthritis Index score, Single Assessment Numeric Evaluation score, and Knee injury and Osteoarthritis Outcome Score. Furthermore, subgroup analyses were performed by stratifying the studies according to the PRP preparation technique to investigate the potential sources of heterogeneity among studies.

Results

Our meta-analysis included nine studies (two RCTs and seven non-RCTs) with 1164 participants. The failure rate in the PRP group was significantly lower than that in the non-PRP group [odds ratio: 0.64, 95% confidence interval (CI) (0.42, 0.96), P = 0.03]. Furthermore, the PRP group was associated with a statistically significant improvement in the visual analog scale for pain [Mean difference (MD): − 0.76, 95% CI (− 1.32, − 0.21), P = 0.007] and Knee injury and Osteoarthritis Outcome Score-symptom [MD: 8.02, 95% CI (2.99, 13.05), P = 0.002] compared with the non-PRP group. However, neither the IKDC score nor the Lysholm knee scale showed any differences between the two groups. In addition, the results of subgroup analyses favored PRP over platelet-rich fibrin matrix (PRFM) regarding the IKDC score.

Conclusions

Although meniscus repairs augmented with PRP led to significantly lower failure rates and better postoperative pain control compared with those of the non-PRP group, there is insufficient RCT evidence to support PRP augmentation of meniscus repair improving functional outcomes. Moreover, PRP could be recommended in meniscus repair augmentation compared with PRFM. PRFM was shown to have no benefit in improving functional outcomes.

The Current Role of Biologics for Meniscus Injury and Treatment

PURPOSE OF REVIEW

There is little doubt that the consensus has changed to favor preservation of meniscal function where possible. Accordingly, the indications for meniscal repair strategies have been refocused on the long-term interest of knee joint health. The development and refinements in surgical technique have been complemented by biological augmentation strategies to address intrinsic challenges in healing capacity of meniscal tissue, with variable effects.

RECENT FINDINGS

A contemporary approach to meniscal healing includes adequate surgical fixation, meniscal and synovial tissue stimulation, and management of the intraarticular milieu. Overall, evidence supporting the use of autogenous or allogeneic cell sources remains limited. The use of FDA-approved medications to effect biologically favorable mechanisms during meniscal healing holds promise. Development and characterization of biologics continue to advance with translational research focused on specific growth factors, cell and tissue behaviors in meniscal healing, and joint homeostasis. Although significant strides have been made in laboratory and pre-clinical studies, translation to clinical application remains challenging. Finally, expert consensus and standardization of nomenclature related to orthobiologics for meniscal preservation will be important for the advancement of this field.

Meniscus treatment: biological augmentation strategies: a narrative review

Objective

An up-to-date description on the biological augmentation strategies for meniscal repair procedures was performed to highlight the main preclinical and clinical evidence available in the literature.

Background

Meniscal repair is a key surgical procedure to preserve as much meniscal tissue as possible to limit the development of knee osteoarthritis (OA). Unfortunately, the results of meniscal repair procedures are not always satisfactory, reporting an overall risk of failure of 25%, likely conditioned due to the poor vascularization of the meniscal tissue. For this reason, several biologic augmentation techniques have been developed to improve the meniscal healing process, ranging from mechanical stimulations to biological products.

Methods

A literature review was conducted on the main biological augmentation procedures combined to the meniscal repair process. A description of the rationale, surgical technique, and preclinical and clinical evidence was performed.

Conclusions

Mechanical stimulations and fibrin clot were the first techniques applied showing several limitations and not exciting results. Recently, platelet-rich plasma (PRP) augmentation to meniscal repair is slowly spreading in the clinical practice. Early evidence from comparative studies showed a significantly lower failure rate in patients treated with PRP augmentation compared with controls. Conversely, the current few and low-level data on mesenchymal stem/stromal cells (MSCs) for meniscal augmentation repair make this a promising but anecdotal topic. Further high-quality clinical studies are needed to support and guide the use of biological strategies for the augmentation of meniscus repair, PRP.

No evidence in support of arthroscopic partial meniscectomy in adults with degenerative and nonobstructive meniscal symptoms: a level I evidence-based systematic review

PURPOSE

It is unclear whether the results of arthroscopic partial meniscectomy (APM) are comparable to a structured physical therapy (PT). This systematic review investigated efficacy of APM in the management of symptomatic meniscal damages in middle aged patients. Current available randomised controlled trials (RCTs) which compared APM performed in isolation or combined with physical therapy versus sham arthroscopy or isolated physical therapy were considered in the present systematic review.

METHODS

This systematic review was conducted according to the 2020 PRISMA statement. All the level I RCTs which investigated the efficacy of AMP were accessed. Studies which included elderlies with severe OA were not eligible, nor were those in which APM was combined with other surgical intervention or in patients with unstable knee or with ligaments insufficiency. The risk of bias was assessed using the software Review Manager 5.3 (The Nordic Cochrane Collaboration, Copenhagen). To rate the quality of evidence of collected outcomes, the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used.

RESULTS

Data from 17 studies (2037 patients) were collected. 48.5% (988 of 2037 patients) were women. The mean age of the patients was 52.7 ± 3.9 years, the mean BMI 27.0 ± 1.3 kg/m². The current evidence suggests no difference in functional PROMs (quality of the evidence: high), clinical PROMs (quality of the evidence: high), pain (quality of the evidence: high), quality of life (quality of the evidence: high), physical performance measures (quality of the evidence: moderate), and OA progression (quality of the evidence: moderate).

CONCLUSIONS

The benefits of APM in adults with degenerative and nonobstructive meniscal symptoms are limited. The current evidence reports similarity in the outcome between APM and PT. Further long-term RCTs are required to investigate whether APM and PT produce comparable results using validated and reliable PROMs. Moreover, future RCTs should investigate whether patients who might benefit from APM exist, clarifying proper indications and outcomes. High quality investigations are strongly required to establish the optimal PT regimes.

LEVEL OF EVIDENCE

Level I.

Cell therapies for chondral defects of the talus: a systematic review

Background

This systematic review investigated the efficacy and safety of surgical procedures augmented with cell therapies for chondral defects of the talus.

Methods

The present systematic review was conducted according to the 2020 PRISMA guidelines. PubMed, Google scholar, Embase, and Scopus databases were accessed in March 2022. All the clinical trials investigating surgical procedures for talar chondral defects augmented with cell therapies were accessed. The outcomes of interest were to investigate whether surgical procedures augmented with cell therapies promoted improvement in patients reported outcomes measures (PROMs) with a tolerable rate of complications.

Results

Data from 477 procedures were retrieved. At a mean follow-up of 34.8 ± 9.7 months, the Visual Analogic Scale (VAS) improved of 4.4/10 (P = 0.002) and the American Orthopaedic Foot and Ankle Score (AOFAS) of 31.1/100 (P = 0.0001) points. No improvement was found in Tegner score (P = 0.4). Few articles reported data on complications. At last follow-up, the rate of reoperation and failure were 0.06% and 0.03%, respectively. No graft delamination or hypertrophy was observed.

Conclusion

The current evidence suggests that cell therapies may be effective and safe to enhance surgical procedures for chondral defects of the talus. These results should be considered within the limitations of the present study. The current literature should be enriched with randomized controlled clinical trials with larger population size and longer follow-up.

Biological augmentation of meniscal repair: a systematic review

PURPOSE

Orthopedic literature remains divided on the utility of biologic augmentation to optimize outcomes after isolated meniscal repair. The aim of this systematic review is to analyze the clinical outcomes and re-operation rates of biologically augmented meniscal repairs.

METHODS

PubMed, CINAHL, Cochrane, and EMBASE databases were queried in October 2020 for published literature on isolated meniscal repair with biological augmentation. Studies were assessed for quality and risk of bias by two appraisal tools. Patient demographics, meniscal tear characteristics, surgical procedure, augmentation type, post-operative rehabilitation, patient reported outcome measures, and length of follow-up were recorded, reviewed, and analyzed by two independent reviewers.

RESULTS

Of 3794 articles, 18 met inclusion criteria and yielded 537 patients who underwent biologic augmentation of meniscal repair. The biologically augmented repair rates were 5.8-27.0% with PRP augmentation, 0.0-28.5% with fibrin clot augmentation, 0.0-12.9% with marrow stimulation, and 0.0% with stem cell augmentation. One of seven studies showed lower revision rates with augmented meniscal repair compared to standard repair techniques, whereas five of seven found no benefit. Three of ten studies found significant functional improvement of biologically augmented repair versus standard repair techniques and six of ten studies found no difference. There was significant heterogeneity in methods for biologic preparation, delivery, and post-operative rehabilitation protocols.

CONCLUSION

Patients reported significant improvements in functional outcomes scores after repair with biological augmentation, though the benefit over standard repair controls is questionable. Revision rates after biologically augmented meniscal repair also appear similar to standard repair techniques. Clinicians should bear this in mind when considering biologic augmentation in the setting of meniscal repair.

LEVEL OF EVIDENCE

IV.

Evidence-based rationale for treatment of meniscal lesions in athletes

Meniscal injuries in elite athletes are a common cause of missed game time and even have the potential to be career shortening. In this patient group, care must be paid not only to the pathology, but also to a player's contract status, time in the season, specific demands of his/her sport and position on the field, and future consequences. Successful treatment requires the clinician to understand the player's goals and needs, communicate effectively between all stakeholders, and a have knowledge of the challenges posed by the different types of meniscal tear seen in this population. Paramount is the distinction between injuries to the medial and lateral meniscus. Deficiency of the lateral meniscus, as a result of a tear or a meniscectomy, leads to frequent early problems and inexorably to chondral degeneration thereby affecting an athlete's ability to perform. Therefore, it is strongly recommended to repair the majority of lateral meniscal tears. Medial meniscal tears pose a more challenging treatment dilemma, as the success of partial meniscectomy in achieving reproducible, early return to play must be balanced against the long-term degenerative consequences. Many meniscal tears are correctly treated non-operatively.Level of evidence V.

Platelet-rich plasma (PRP) augmentation does not result in more favourable outcomes in arthroscopic meniscal repair: a meta-analysis

Background

The efficacy and safety of platelet-rich plasma (PRP) augmentation for arthroscopic meniscal repair is controversial. This meta-analysis compared arthroscopic meniscal repair performed in isolation or augmented with PRP.

Methods

The present study was conducted according to PRISMA 2020 guidelines. Pubmed, Web of Science, Google Scholar and Embase were accessed in August 2021. All the clinical trials which compared arthroscopic meniscal repair performed in isolation or augmented with PRP were included.

Results

Eight hundred thirty-seven patients were included: 38% (318 of 837 patients) were women; the mean age of the patients was 35.6 (range, 20.8–64.3) years; the mean follow-up was 26.2 (range, 6–54) months. Similarity was found in analogue scale (VAS) (P = 0.5) and Lysholm (P = 0.9), and International Knee Documentation Committee (IKDC) scores (P = 0.9). Similarity was found in the rate of failure (P = 0.4) and rate of revision (P = 0.07).

Conclusion

The current published scientific evidence does not support PRP augmentation for arthroscopic meniscal repair.

Study on the Application of PRP Enriched with Hyaluronic Acid to Skin Wounds-Macroscopic Result

Tissue healing is a complex process of replacing damaged tissue structures, being a dynamic process with spatial and temporal involvement. In practice, there are three types of healing: primary, secondary and tertiary. Since even tertiary healing can cause different problems depending on the individual patient, the medical world has always strived for new, easier, more effective, faster, and low cost-effective methods to cover skin wounds. This experiment aims to find a method that is as efficient and fast as possible, with minimal costs, of native healing of skin wounds and the development of a protocol that is as reliable and safe as possible for the patient. The experiment was carried out within the animal facility of the University of Medicine and Pharmacy of Craiova, with the agreement of our institutional Ethics Committee. The experimental group consisted of 30 individuals (Wistar laboratory rats), clinically healthy, male and female, being divided into 3 sublots of 10 individuals each. Each sublot was sacrificed at different time intervals: 7, 14 and 21 days, respectively. The local evolution of each individual was monitored during the experimental days, as well as their general state of health. Before slaughter, the lesions were examined macroscopically, following their size, whether or not the infection was present and the presence of other self-inflicted lesions later. Macroscopically, a faster wound healing was found where PRP enriched with hyaluronic acid was applied from the 7th day, so we can say that at first glance the "free" healing period in the case of enhanced epithelialization was about 7 days shorten. This fact will be confirmed or refuted following histopathological examinations and immunohistochemistry.

The use of autologous platelet-rich fibrin matrix combined with meniscal repair in the treatment of parameniscal cyst: clinical results and cyst recurrence after 2-year of follow up

Purpose

Parameniscal cysts are associate with horizontal meniscal tears. Arthroscopic meniscal repair and the excision of the cyst by mini-open approach represent a valid treatment. However, the recurrence of cyst is still a current issue. Therefore, biological factors may be considered to promote the biological repair and avoid recurrence. The aim of the present study was to report the clinical results and the rate of recurrence of the cyst after minimum 2-year of follow up in a cohort of patients treated by meniscal repair and autologous platelet-rich fibrin matrix augment.

Methods

Patients with lateral parameniscal cyst undergoing arthroscopic meniscal repair and autologous platelet-rich fibrin matrix augment between 2016 and 2019 were retrospectively reviewed in March 2021. Inclusion criteria were absence of prior surgery on the affected knee with minimum 2-year of follow-up. Exclusion criteria were concomitant ligament lesions, rheumatic diseases and knee osteoarthritis. After reviewing the database, each selected patient was contacted and asked to participate in the study; at the follow-up evaluation all patient signed an informed consent. Tegner-Lysholm knee score, IKDC and NRS were collected before surgery and at follow-up.

Results

This study included 15 patients (8 male) with mean age of 32.8 years old. No recurrence of the cysts was observed. The Tegner-Lysholm knee score and IKDC subjective scores increased respectively from 41.3 ± 5.4 and 37.6 ± 5.1 at baseline to 92.3 ± 4.6 and 89.4 ± 2.6 at the final follow up. Concerning pain relief, the Numeric Pain Rating Scale (NRS) displayed a significant improvement reaching at the follow up a score of 1,3 ± 1.1 in comparison to 6.8 ± 0.9 at the baseline.

Conclusion

Surgical management of symptomatic lateral parameniscal cyst with cyst excision, autologous PRP membrane application and meniscus repair demonstrated excellent subjective clinical outcome with any cyst reoccurrence.

Level of evidence

III, retrospective cohort study.

Platelet-Rich Fibrin Decreases the Inflammatory Response of Mesenchymal Cells

Chronic inflammation is a pathological process where cells of the mesenchymal lineage become a major source of inflammatory mediators. Platelet-rich fibrin (PRF) has been shown to possess potent anti-inflammatory activity in macrophages, but its impact on mesenchymal cells has not been investigated. The aim of this study was, therefore, to expose mesenchymal cells to inflammatory cytokines together with lysates generated from liquid platelet-poor plasma (PPP), the cell-rich buffy coat layer (BC; concentrated-PRF or C-PRF), and the remaining red clot layer (RC), following centrifugation of blood. Heating PPP generates an albumin gel (Alb-gel) that when mixed back with C-PRF produces Alb-PRF. Membranes prepared from solid PRF were also subjected to lysis. We report here that lysates of PPP, BC, and PRF decreased the cytokine-induced expression of interleukin 6 (IL6) and nitric oxide synthase (iNOS) in the bone marrow-derived ST2 cells. Consistently, PPP, BC, and PRF greatly decreased the phosphorylation and nuclear translocation of p65 in ST2 cells. The inflammatory response caused by Pam3CSK4 was reduced accordingly. Moreover, PPP, BC, and PRF reduced the enhanced expression of inflammatory mediators IL6 and iNOS in 3T3-L1 pre-adipocyte mesenchymal cells, and iNOS and CCL5 in murine calvarial cells. Surprisingly, PRF lysates were not effective in reducing the inflammatory response of human gingival fibroblasts and HSC2 epithelial cells. The data from the present study suggest that both liquid PRF and solid PRF exert potent anti-inflammatory activity in murine mesenchymal cells.

Platelet-Rich Plasma Augmentation of Meniscal Repair in the Setting of Anterior Cruciate Ligament Reconstruction

BACKGROUND

The increasing incidence of anterior cruciate ligament (ACL) and meniscal injuries has led to strong interest in discovering new methods to enhance the biological healing response of these tissues. Platelet-rich plasma (PRP) contains various growth factors associated with a positive healing response, but few existing clinical studies are available to determine the risks and benefits of these therapies.

PURPOSE

To determine the effects of intraoperative PRP on postoperative knee function and complications at 2 years after ACL reconstruction with meniscal repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective matched case-control study was conducted between 2013 and 2017 using a single surgeon database of 1014 patients undergoing primary ACL reconstruction with concomitant meniscal repair, resulting in 324 patients (162 PRP patients and 162 control patients) who met the study criteria. Patients were matched by age, sex, graft type, and meniscal injury. The Single Assessment Numeric Evaluation (SANE) was administered at 2 years, and injury surveillance was conducted. Secondary outcomes included the time to return to activity (months), self-reported knee function (International Knee Documentation Committee [IKDC] score), functional performance testing (knee range of motion, single-leg balance, single-leg hopping, agility testing), and postoperative complications (graft failure, infection, loss of motion [requiring repeat arthroscopy for lysis of adhesions], venous thrombosis, etc). Univariate models were used for between-group comparisons, and alpha was set at .05 for all analyses.

RESULTS

No differences were found in SANE knee function scores between the PRP and matched-control groups at 2 years (91.6 ± 11.2 vs 92.4 ± 10.6, respectively; P = .599). Additionally, no differences were reported between groups for self-reported function (IKDC score, 87.6 ± 13.3 vs 88.1 ± 12.6; P = .952), functional performance testing (P > .05), and timing of return to activity (7.8 ± 1.9 vs 8.0 ± 1.9 months; P = .765). The PRP group demonstrated a higher rate of postoperative knee motion loss compared with the control group (13.6% vs 4.6%; P < .001). No other differences were observed in postoperative complications (P > .05).

CONCLUSION

The added use of intraoperative PRP did not improve self-reported knee function, functional performance, and timing of return to activity for patients undergoing ACL reconstruction with meniscal repair. Furthermore, the use of PRP may have negative consequences for regaining knee range of motion after surgery. On the basis of these data, surgeons should cautiously consider the application of PRP when planning surgery for intra-articular injuries of the knee.

REGISTRATION

NCT03704376 (ClinicalTrials.gov identifier).

Development of Vancomycin Delivery Systems Based on Autologous 3D Platelet-Rich Fibrin Matrices for Bone Tissue Engineering

Autologous platelet-rich fibrin (PRF) is derived from the blood and its use in the bone tissue engineering has emerged as an effective strategy for novel drug and growth factor delivery systems. Studies have approved that combined therapy with PRF ensures higher biological outcomes, but patients still undergo additional treatment with antibiotic drugs before, during, and even after the implantation of biomaterials with PRF. These systematically used drugs spread throughout the blood and lead not only to positive effects but may also induce adverse side effects on healthy tissues. Vancomycin hydrochloride (VANKA) is used to treat severe Staphylococcal infections but its absorption in the target tissue after oral administration is low; therefore, in this study, we have developed and analyzed two kinds of VANKA carriers—liposomes and microparticles in 3D PRF matrices. The adjustment, characterization, and analysis of VANKA carriers in 3D PRF scaffolds is carried out in terms of encapsulation efficiency, drug release kinetics and antibacterial activity; furthermore, we have studied the micro- and macrostructure of the scaffolds with microtomography.

Meniscal repair: The current state and recent advances in augmentation

Meniscal injuries represent one of the most common orthopedic injuries. The most frequent treatment is partial resection of the meniscus, or meniscectomy, which can affect joint mechanics and health. For this reason, the field has shifted gradually towards suture repair, with the intent of preservation of the tissue. "Save the Meniscus" is now a prolific theme in the field; however, meniscal repair can be challenging and ineffective in many scenarios. The objectives of this review are to present the current state of surgical management of meniscal injuries and to explore current approaches being developed to enhance meniscal repair. Through a systematic literature review, we identified meniscal tear classifications and prevalence, approaches being used to improve meniscal repair, and biological- and material-based systems being developed to promote meniscal healing. We found that biologic augmentation typically aims to improve cellular incorporation to the wound site, vascularization in the inner zones, matrix deposition, and inflammatory relief. Furthermore, materials can be used, both with and without contained biologics, to further support matrix deposition and tear integration, and novel tissue adhesives may provide the mechanical integrity that the meniscus requires. Altogether, evaluation of these approaches in relevant in vitro and in vivo models provides new insights into the mechanisms needed to salvage meniscal tissue, and along with regulatory considerations, may justify translation to the clinic. With the need to restore long-term function to injured menisci, biologists, engineers, and clinicians are developing novel approaches to enhance the future of robust and consistent meniscal reparative techniques.

Regenerative medicine: characterization of human bone matrix gelatin (BMG) and folded platelet-rich fibrin (F-PRF) membranes alone and in combination (sticky bone)

During the last two decades autologous platelet and leukocyte rich products (PRP; PRF), opened new perspectives in regenerative medicine. In particular regenerative dentistry played a pioneer role in the application of these products in bone regenerative cases. Many aspects of cytokines, such as, growth factor release, blood cell content and its characterization were reported, but some practical questions are still unanswered in the preparation of PRF membranes and sticky bones. A new folding technique was introduced that created a good quality, pliable, and strong F-PRF membrane with a dense fibrin network and more homogenous blood cell distribution. F-PRF produced a very promising sticky bone combined with human freeze-dried cortical bone matrix gelatin (BMG). There hasn’t been much focus on the quality and character of the applied bone and the optimal membrane/bone particle ratio has not been reported. A 0.125 g BMG/ml plasma (1 g/8 ml) seems like the ideal combination with maximal BMG adhesion capacity of the membrane. Particle distribution of BMG showed that 3/4 of the particles ranged between 300–1000 µ, the remnant 1/4 was smaller than 300 µ. The whole F-PRF membrane and its parts were compared with conventional A-PRF membrane concerning their resistance against proteolytic digestion. The F-PRF was superior to A-PRF, which dissolved within 4–5 days, while F-PRF was destroyed only after 11 days, so this provides a better chance for local bone morphogenesis. The F-PRF pieces had similar resistance to the whole intact one, so they can be ideal for surgical procedures without risk of fast disintegration.

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.

Biologic Augmentation Reduces the Failure Rate of Meniscal Repair: A Systematic Review and Meta-analysis

Background

Clinical results after isolated meniscal repair are not always satisfactory, with an overall failure rate of around 25%. To improve the success rate of meniscal repair, different biologic augmentation techniques have been introduced in clinical practice, but their real efficacy is still controversial.

Purpose/Hypothesis

To evaluate the safety, clinical results, and failure rate of biologic augmentation techniques for meniscal repair. The hypothesis was that biologic augmentation would improve the results of meniscal repair.

Study Design

Systematic review and meta-analysis of comparative studies.

Methods

A systematic review of the literature was performed in March 2020 of 3 electronic databases (PubMed, Scopus, and the Cochrane Library) regarding meniscal repair combined with biologic augmentation techniques. Articles combining biologic augmentation with other surgical procedures besides meniscal suture were excluded. The quality of the included studies was assessed using a modified Coleman Methodology Score, and the risk of bias was evaluated using the ROBINS-I (Risk of Bias in Non-randomized Studies of Interventions) and the RoB 2.0 (Revised Tool for Risk of Bias in Randomized Trials) for nonrandomized and randomized controlled trials, respectively.

Results

A total of 11 studies were included in the qualitative analysis: platelet-rich plasma (PRP) augmentation in 6 comparatives studies, fibrin clot augmentation in 2 case series, and mesenchymal stem cells augmentation in 2 case series and 1 case report. One severe adverse event of septic arthritis was reported for PRP 1 month after surgery. The quality of evidence evaluated with the modified Coleman Methodology Score was low overall. Five studies reporting on 286 patients (111 PRP augmentation, 175 control) were included in the quantitative synthesis. A significantly lower risk of failure was documented in the PRP augmentation group as compared with the control group: 9.9% (4.5%-19.1%) versus 25.7% (12.7%-38.7%) (P < .0005).

Conclusion

The literature on biologic meniscal augmentation is recent and scarce. Only a few comparative trials are available, all focusing on the potential of PRP. The meta-analysis documented that PRP is safe and useful in improving the survival rate, with a 9.9% rate of failure versus 25.7% for the control group. Further high-level studies are needed to confirm these findings and identify the most effective biologic augmentation strategy to improve the outcome of meniscal repair.

Platelet-Rich Plasma Augmentation for Isolated Arthroscopic Meniscal Repairs Leads to Significantly Lower Failure Rates: A Systematic Review of Comparative Studies

Background:

Studies have reported relatively high failure rates of isolated meniscal repairs. Platelet-rich plasma (PRP) has been suggested as a way to increase growth factors that enhance healing.

Purpose:

To compare (1) meniscal repair failures and (2) patient-reported outcomes after isolated arthroscopic meniscal repair augmented with and without PRP.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic review was performed using the PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines. Multiple databases were searched for studies that compared outcomes of isolated arthroscopic meniscal repair augmented with PRP versus without PRP in human patients. Failures and patient-reported outcome scores were reported for each study and compared between groups. Study heterogeneity was assessed using I² for each outcome measure before meta-analysis. Study methodological quality was analyzed. Continuous variable data were reported as mean and standard deviation from the mean. Categorical variable data were reported as frequency with percentage. All P values were reported with significance set at P < .05.

Results:

Five articles were analyzed (274 patients [110 with PRP and 164 without PRP]; 65.8% male; mean age, 29.1 ± 4.6 years; mean follow-up, 29.2 ± 22.1 months). The risk of meniscal repair failure ranged from 4.4% to 26.7% for PRP-augmented repairs and 13.3% to 50.0% for repairs without PRP. Meniscal repairs augmented with PRP had significantly lower failure rates than repairs without PRP (odds ratio, 0.32; 95% CI, 0.12-0.90; P = .03). One of the 5 studies reported significantly higher outcomes in the PRP-augmented group versus the no-PRP group for the International Knee Documentation Committee (IKDC), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee injury and Osteoarthritis Outcome Score (KOOS) (P < .05 for all). The remaining 4 studies reported no significant difference between groups with regard to outcomes for the IKDC, Lysholm knee scale, visual analog scale for pain, or Tegner activity level.

Conclusion:

Although the studies were of mostly of low quality, isolated arthroscopic meniscal repairs augmented with PRP led to significantly lower failure rates (10.8% vs 27.0%; odds ratio, 0.32; P = .03) as compared with repairs without PRP. However, most studies reported no significant differences in patient-reported outcomes.

Cytokine Expression Pattern and Protein-Protein interaction network analysis of Leucocyte Rich Platelet Rich Fibrin and Injectable Form of Platelet Rich Fibrin

PURPOSE

Platelet-rich fibrin (PRF) such as leucocyte-rich PRF (L-PRF) and injectable form of PRF (i-PRF) are widely used in various surgical applications. L-PRF- and i-PRF-derived cytokine variations and functional pathways are still unexplored. The aim of the study was to evaluate the expression pattern of Th1-, Th2-, and Th17-related cytokines by L-PRF and i-PRF under in vitro.

METHODS

Cytokine levels were evaluated using multi-analyte ELISArray kit. Using elevated level of cytokines, the protein-protein interaction and pathway were predicted by computational method.

RESULTS

The expressed cytokine levels were higher in L-PRF than in i-PRF. Specifically in L-PRF, IL8, IL2, IL6, and IL1A were expressed abundantly, whereas IL4, IL10, and IL6 were significantly high in i-PRF. Furthermore, protein-protein interaction (PPI) networks (cytokine-cytokine interactions) and pathway analyses were predicted using higher-order cytokines. PPI networks and gene ontology enrichment analysis showed functional variations between L-PRF and i-PRF. Kyoto Encyclopedia of Gene and Genome pathway analysis found that L-PRF mediates NF-k B signaling, Toll-like receptor signaling (TLR), and MAPK signaling via T-cell receptor signaling pathway. i-PRF is significantly involved in JAK-STAT signaling pathway through upregulation of STAT1.

CONCLUSION

Our study concludes that L-PRF and i-PRF act via different pathways that confirm functional variations between them. Therefore, we speculate that L-PRF may be effective in acute phase of chronic wounds such as in diabetes mellitus and immunocompromised patients whereas i-PRF may have a better outcome in acute wounds.

Engineering Anisotropic Meniscus: Zonal Functionality and Spatiotemporal Drug Delivery

Human meniscus is a fibrocartilaginous structure that is crucial for an adequate performance of the human knee joint. Degeneration of the meniscus is often followed by partial or total meniscectomy, which enhances the risk of developing knee osteoarthritis. The lack of a satisfactory treatment for this condition has triggered a major interest in drug delivery (DD) and tissue engineering (TE) strategies intended to restore a bioactive and fully functional meniscal tissue. The aim of this review is to critically discuss the most relevant studies on spatiotemporal DD and TE, aiming for a multizonal meniscal reconstruction. Indeed, the development of meniscal tissue implants should involve a provision for adequate active molecules and scaffold features that take into account the anisotropic ultrastructure of human meniscus. This zonal differentiation is reflected in the meniscus biochemical composition, collagen fiber arrangement, and cell distribution. In this sense, it is expected that a proper combination of advanced DD and zonal TE strategies will play a key role in the future trends in meniscus regeneration. Impact statement Meniscus degeneration is one of the main causes of knee pain, inflammation, and reduced mobility. Currently used suturing procedures and meniscectomy are far from being ideal solutions to the loss of meniscal function. Therefore, drug delivery (DD) and tissue engineering (TE) strategies are currently under investigation. DD systems aim at an in situ controlled release of growth factors, whereas TE strategies aim at mimicking the anisotropy of native meniscus. The goal of this review is to discuss these two main approaches, as well as synergies between them that are expected to lead to a real breakthrough in the field.

The Clinical Use of Platelet-Rich Plasma in Knee Disorders and Surgery-A Systematic Review and Meta-Analysis

In recent years, the interest in biological treatment of knee lesions has increased, especially the application of platelet-rich plasma is of particular note. The number of articles evaluating platelet-rich plasma (PRP) efficacy in the recovery of knee disorders and during knee surgery has exponentially increased over the last decade. A systematic review with meta-analyses was performed by assessing selected studies of local PRP injections to the knee joint. The study was completed in accordance with 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A multistep search of PubMed, Embase, Cochrane Database of Systematic Reviews, and Clinicaltrials.gov was performed to identify studies on knee surgery and knee lesion treatment with PRP. Of the 4004 articles initially identified, 357 articles focusing on knee lesions were selected and, consequently, only 83 clinical trials were analyzed using the revised Cochrane risk-of-bias tool to evaluate risk. In total, seven areas of meta-analysis reported a positive effect of PRP. Among them, 10 sub-analyses demonstrated significant differences in favor of PRP when compared to the control groups (p < 0.05). This study showed the positive effects of PRP, both on the recovery of knee disorders and during knee surgery; however further prospective and randomized studies with a higher number of subjects and with lower biases are needed.

Role of Platelet-Rich Fibrin (PRF) and Platelet-Rich Plasma (PRP) in Oro-Facial Tissue Regeneration: A Narrative Review

Background and Aim:

Regeneration potential of platelet-rich fibrin (PRF) and platelet-rich plasma (PRP) in oral tissues regeneration has revolutionized the clinical dentistry in recent years. The in vivo and in vitro research on PRP and PRF has opened a new avenue in the dentistry and medicinal care. It is a minimally invasive and cost-effective technique that will raise the bar of clinical dentistry. The results presently documented are overwhelming; the potential to use PRF and PRP in the clinical dentistry have improved dental quality, satisfaction, and clinical outcome. The aim of the review was to recapitulate the regenerative and healing potential of platelet extracts in different disciplines of clinical dentistry.

Materials and Methods:

The attempt was to answer the following question: what are the various clinical oral health applications for PRF and PRP available in the published literature? The dual functions (tissue sealants and drug delivery systems to carry biomolecules and chemotactic growth factors) have helped the practitioners to treat the complicated oral conditions and tissues regeneration. The PRF and plasma has emerged as a powerful therapeutic tool for management of soft and hard tissue healing and regenerative procedures, including implant osseointegration. More research is mandatory to use these platelets concentrate to their full potential in various clinical applications.

Conclusion:

PRF is an emerging therapeutic tool in the management of oral soft and hard tissue healing and regenerative procedures.

Platelet-Rich Plasma Reduces Failure Risk for Isolated Meniscal Repairs but Provides No Benefit for Meniscal Repairs With Anterior Cruciate Ligament Reconstruction

BACKGROUND

The effect of platelet-rich plasma (PRP) on the risk of meniscal repair failure is unclear. Current evidence is limited to small studies without comparison between isolated repairs and meniscal repairs with concomitant anterior cruciate ligament (ACL) reconstruction. It is also unclear whether the efficacy of PRP differs between preparation systems in the setting of meniscal repair.

PURPOSE

(1) To determine whether intraoperative PRP affects the risk of meniscal repair failure. (2) To determine whether the effect of PRP on meniscal failure risk is influenced by ACL reconstruction status or by PRP preparation system.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The study entailed 550 patients (mean ± SD age, 28.8 ± 11.2 years) who underwent meniscal repair surgery with PRP (n = 203 total; n = 148 prepared with GPS III system, n = 55 prepared with Angel system) or without PRP (n = 347) and with (n = 399) or without (n = 151) concurrent ACL reconstruction. The patients were assessed for meniscal repair failure within 3 years. The independent effect of PRP on the risk of meniscal repair failure was determined by multivariate Cox proportional hazards modeling with adjustment for age, sex, body mass index, ACL status, tear pattern, tear vascularity, repair technique, side (medial or lateral), and number of sutures or implants used.

RESULTS

Failures within 3 years occurred in 17.0% of patients without PRP and 14.6% of patients with PRP (P = .60) (Angel PRP, 15.9%; GPS III PRP, 14.2%; P = .58). Increased patient age was protective against meniscal failure regardless of ACL or PRP status (per 5-year increase in age: adjusted hazard ratio [aHR], 0.90; 95% CI, 0.81-1.0; P = .047). The effect of PRP on meniscal failure risk was dependent on concomitant ACL injury status. Among isolated meniscal repairs (20.3% failures at 3 years), PRP was independently associated with lower risk of failure (aHR, 0.18; 95% CI, 0.03-0.59; P = .002) with no difference between PRP preparation systems (P = .84). Among meniscal repairs with concomitant ACL reconstruction (14.1% failures at 3 years), PRP was not independently associated with risk of failure (aHR, 1.39; 95% CI, 0.81-2.36; P = .23) with no difference between PRP preparation systems (P = .78).

CONCLUSION

Both PRP preparations used in the current study had a substantial protective effect in terms of the risk of isolated meniscal repair failure over 3 years. In the setting of concomitant ACL reconstruction, PRP does not reduce the risk of meniscal repair failure.

The Clinical Use of Biologics in the Knee Lesions: Does the Patient Benefit?

PURPOSE OF REVIEW

Overview the outcomes of the latest use of platelet-rich plasma (PRP) for the treatment of knee lesions in the clinics and discuss the challenges and limitations.

RECENT FINDINGS

Recent clinical studies mainly indicate there may be benefit of PRP usage for the treatment of knee lesions. As an autologous source of bioactive components, PRP has been shown to be typically safe, free of major adverse outcomes. The use of PRP has been continuously increasing, and some well-designed, double-blinded, placebo-controlled clinical trials have been published. Clinical outcomes relating to PRP usage are multifactorial and depend on the severity of the lesion and patient characteristics. Although PRP is safe to use and it can be easily applied in the clinics, case-specific considerations are needed to determine whether PRP could be beneficial or not. If the use of PRP is favored, then, the configuration/optimization of the preparation and administration/delivery strategy with or without a concomitant treatment may further enhance the clinical outcomes and patients' experience.