Purpose. Platelet Rich Plasma (PRP) has been shown to have positive effect in tendon regeneration in in-vitro and limited in-vivo animal studies. We aim to study PRP use in acute Achilles tendon rupture (ATR) regeneration in a purposely designed clinical trial. Methods. This is a prospective double-arm patient-blinded randomized controlled trial. ATR patients were randomized into PRP treatment or control groups. Non-operatively treated patients received PRP or control injection in clinic. In operatively treated patients, PRP gel was applied in the ruptured gap during percutaneous repair. Standard rehabilitation protocol was used and patients were followed up for 24 weeks. ATR, VISA-A and FAOS scores were used as subjective outcome measures. Functional ultrasound Elastography (FUSE) was performed at each follow-up to assess the mechanical properties of tendons. PRP analysis and tendon needle-biopsy were performed to study the histological differences during healing in both groups. Results. 20 patients were recruited with mean age 37.5±8.8 (8males and 7 females). Rupture location was 4.8±2.1 cm from insertion. PRP platelet count 1044±320 × 1000/μL with average platelet CD62p activation 68.42±4.5%. Mixed linear regression analysis revealed PRP treated tendon achieved better ATR and VISA-A outcome scores (p<0.05). FAOS score analysis showed that PRP group had better pain, ADL and symptoms scores with significant difference apparent from week 3 onwards. Strain mapping using FUSE scan in 4 patients showed bigger harder tendons in PRP group. Analysis of the remaining patients is on the way. To achieve the desired statistical power in pragmatic settings, recruitment will continue in a multi-centre trial. Conclusion. Our preliminary findings show that PRP application in Achilles tendon rupture may lead to faster regeneration and return to function as supported by a combination of objective and subjective outcome measures

Meniscal cartilage provides joint stabilisation, load distribution, impact absorption and decreased friction in joints that have a complex movement such as the knee. If the meniscal cartilage degrades or is surgically removed, there is a strong probability, over time, of damage to the articular surface. The ability to regenerate damaged meniscal cartilage with an implanted device that replaces the biological equivalent would allow for joint stabilisation, robust movement and reduce the risk of damage to the articular cartilage. An implant with many of the characteristics of meniscus and with the ability to integrate correctly and firmly with the surrounding tissue, would be advantageous. Inclusion of Platelet Rich Plasma (PRP) into the scaffolds to provide a concentrated source of matrix proteins and autologous growth factors may further enhance the regenerative repair process. To investigate the suitability of the collagen scaffolds, addition of meniscal chondrocytes and or PRP was examined in vitro. Human meniscal chondrocyte cells were isolated, via collagenase digestion, from meniscal cartilage recovered from total knee replacement surgery. Meniscal chondrocytes were cultured in vitro to expand cell numbers. PRP was produced from volunteer's blood using a centrifuge and density based platelet recovery system. Release of Platelet Derived Growth Factor type AB (PDGF-AB) was measured by ELISA as an indicator of the behaviour of the peptide growth factor component. Combinations of scaffold, meniscal chondrocytes and PRP were tested for interaction, suitability and viability. Experiments so far have shown good biocompatibility, in vitro, as meniscal chondrocytes were able to grow within the range of scaffolds produced. Cell retention could be enhanced by addition of PRP to the scaffolds. PDGF-AB was released over 5 days from the scaffold and PRP combination. Further studies are in progress to derive relevant scaffold modifications and combinations for practical, robust, treatment strategies

Disease modifying approaches are commonly applied in OA patients. An aging society with better life expectancies is increasing in Europe and the globe. Orthobiologics cover intraarticular hyaluronan injections and also cellular therapies. Cellular therapies range from platelet rich plasma (PRP) applications to exosomes. Short term follow-up of limited number of patients revealed favorable results in clinical cellular therapies. Most of these studies evaluated decrease of pain and increase in function. Recent basic science studies focused on the action mechanism of orthobiologic therapies however patient perspective is less studied. Our research team has recently performed a qualitative study on the patient perspective of hyaluronan injection of the knee joint. Findings of that study will be shared and future patient knowledge based options on orthobiologics will be discussed

Degenerative disc disease, associated to low back pain, afflicts more than 50% of humans, and represents a major healthcare problem, especially for the pathology initiation. Current treatments range from conservative strategies to more invasive surgical techniques, such as disc removal and vertebral fusion. In the Intervertebral Disease (IVD) the nucleus pulposus (NP) degeneration is a key factor for the pathology initiation. Several tissue engineering approaches aiming to restore the appropriate NP cell (NPCs) and matrix content, were attempted by using adult stromal cells either from bone marrow or adipose tissue, chondrocytes, notochordal cells and more recently also pluripotent stem cells. However, none was fully satisfactory since the NP acid and a-vascularized environment appeared averse to the implanted heterologous cells. Several studies demonstrated the efficacy of platelet derivatives such as platelet rich plasma (PRP) in promoting the regeneration of connective tissues. We investigated the efficacy of PRP on NPCs proliferation and differentiation with the goal to propose the direct stimulation of resident cells (stimulation of endogenous cells – less invasive surgical procedure) or the implantation of NPCs expanded in vitro in the presence of PRP as therapeutic agents in IVD degeneration. NPCs were isolated from small fragments of NP explants, cultivated in medium supplemented with PRP or FCS (standard condition control) and characterized by FACS analysis for the expression of the typical mesenchymal stem cells markers CD34, CD44, CD45, CD73, CD90 and CD105. NPCs cultured in PL showed a phenotypic profile like the cells cultured in FCS. However, compared to NPCs expanded in the presence of FCS, NPCs expanded in PRP showed a much better proliferation and differentiation capacity. NPCs differentiation was evaluated by the cell ability to produce an organized metachromatic cartilaginous matrix, confirmed by the positive immunohistochemical staining for chondrogenic markers

Platelet Rich Plasma (PRP), either rich (L-PRP) or poor (P-PRP) of leukocytes, is frequently used as an anti-inflammatory and regenerative tool in osteoarthritis (OA). PRP contains proteins but not genes as it is derived from megakaryocytes. Proteomics but not metabolomics of PRP was recently studied. Metabolomics is a field of ‘omics’ research involved in comprehensive portrayal of the small molecules, metabolites, in the metabolome. These small molecules can be endogenous metabolites or exogenous compounds found in an organism (1). Our aim was to determine the difference between L-PRP and P-PRP. A cross-sectional clinical study was designed in six recreational male athletes between the ages of 18 and 35 years. 3 mL P-PRP and 3 mL -LPRP was prepared from 60 mL of venous blood after treating with 9 mL of sodium citrate and centrifugation at 2.700 rpm for 10 min. Half of the prepared PRP's were frozen at −20°C for a week. Fresh and frozen samples were analyzed at the Q-TOF LC/MS device after thawing to room temperature. Untargeted metabolomic results revealed that the metabolomic profile of the L-PRP and P-PRP were significantly different from each other. A total of 33.438 peaks were found. Statistically significant (p<0.05) peaks were uploaded to the MetaboAnalyst 5.0 platform. Exogenous out of 2.308 metabolites were eliminated and metabolites found significant for our study were subjected to pathway analysis. Steroid biosynthesis, sphingolipid metabolism and metabolism of lipid pathways were affected. In the L-PRP samples, Nicotinamide riboside (FC: 2.2), MHPG (FC: 3.0), estrone sulfate (FC: 7.5), thiamine diphosphate (FC: 2.0), leukotriene E4 (FC: 7.5), PC(18:1 (9Z)e/2:0) (FC: 9.8) and Ap4A (FC: 2.1) were higher compared to P-PRP. C24 sulfatide (FC: −11.8), 3-hexaprenyl-4,5-dihydroxybenzoic acid (FC: −2.8) metabolites were furthermore lower in P-PRP. Clinical outcomes of PRP application should consider these metabolic pathways in future studies (2)

Abstract. Background. Lateral and medial epicondylitis, more commonly known as Tennis and Golfer's elbow, can cause chronic pain and significant functional impairment in working-age patients. For patients with refractory epicondylitis, platelet rich plasma (PRP) of which ACP is a type, is commonly used as an alternative to surgical intervention, but its efficacy is unproven. Objective. To assess the mid-term outcomes of ultrasound guided ACP injections for patients with refractory epicondylitis who have failed conventional conservative treatment. Methods. 77 patients who were treated with PRP for refractory epicondylitis were included in the study. The mean age of patients was 50.3 years (range 36–70), with 30% men and 70% women. The Oxford Elbow Score (OES) and progression to surgery were used to assess the mid-term outcomes. Results. The mean follow up duration was 2.1 years (range 1.0 – 4.2). Post-procedure OES was recorded for thirty-three patients, of these, thirty-one patients (94.0%) demonstrated an improvement in their OES at mid-term follow-up compared to their pre-op score. The mean change in OES was +16 (range −7 to +34), 81.8% exhibited a minimally important change (MIC) in OES of greater than 8.2 points. Of all seventy-seven patients, seventeen (22.1%) underwent open release and twenty-seven (35.1%) patients were lost to follow up. Conclusion. Ultrasound guided ACP injections can be an effective treatment for refractory epicondylitis and is likely to prevent the need for surgery. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

The goal of surgery for osteochondral lesions is to regenerate the damaged cartilage with ideally hyaline cartilage. The current gold standard treatment is bone marrow stimulation (BMS) by microfracture. In reality however BMS typically results in the generation of fibrocartilage. Orthobiologics including bone marrow aspirate, platelet rich plasma and hyaluronic acid products have been shown to promote cartilage healing and potentially increase the formation of hyaline cartilage in treated lesions. However the role of these products, the timing of their administration and frequency of application are still not clearly defined and their routine use is still not recommended. These issues and future directions for research and future clinical application will be discussed

The aim of this study was to evaluate the trochlear bone and cartilaginous regeneration of rabbits using a composite based on platelet rich plasma (PRP), chitosan and hydroxyapatite. The study was approved by the ethics committee of the Federal University of Campina Grande under number 72/2017. Surgical holes measuring four millimetres in diameter were performed in rabbit trochleae, one surgical hole in each animal remained empty and another one was filled with the composite. Clinical-orthopaedic and radiographic evaluations were carried out for 60 days, after which the animals were euthanized for histomorphometric evaluations. Clinical-evaluations exhibited lameness of two members of the treatment (T) group and one member of control (C) group. The radiographic evaluation of T group exhibited absence of subchondral bone reaction (33%); nonetheless, presence of moderate subchondral bone reaction was more frequently reported in group C with 67%. Microscopic evaluation revealed the presence of tissue neoformation, composed of dense connective tissue. Microscopic findings were similar in both groups, with a difference in the amount of neoformed tissue, which was confirmed after the morphometric analysis, revealing a significant difference in the quantity of newly formed tissue at the bone / cartilage / implant interface in the T group. The results indicate that the composite based on chitosan, hydroxyapatite and PRP enhanced bone and cartilage healing

Introduction. Platelet Rich Plasma (PRP) is widely used in clinical praxis. Especially the effects in musculoskeletal repair studies are diverse and an augmentation of healing processes stays questionable. However, diverse cell culture studies reported promising results, which seem not be transferable into the clinical situation. We therefore performed a cell culture study which better reflects the clinical situation: the autologous stimulation of human tendon cells with PRP. Materials and Methods. Human tenocyte-like cells (hTLCs) from 24 donors (12 male/female) with supraspinatus tendon tears were isolated and characterized. The donors were grouped into 4 groups according to their age (</> 65 years) and sex. During follow up, approximately 2.5 years after initial surgery, the patients donated blood for PRP preparation (Ethic vote and written informed consent). Growth factors and platelets were quantified and the effect of autologous stimulation of the hTLCs was measured by analysis of cell proliferation, Collagen I synthesis and expression of Collagen I, III and Osteocalcin. Results. The platelet concentration for the 4 groups was between 3.6–4.5 × 10. 5. platelets/µl (reference level: 1.5–3×10. 5. platelets/µl blood). PRP contained high amounts of IGF-1, lower amounts of TGF-β1 and PDGF-AB. PDGF-AB concentration significantly correlated with platelet concentration and the TGF-β1 concentration. The amounts of BMP-7 and −12 were underneath the detection limits of the assays. Cell proliferation was positively affected by PRP exposure when compared to controls (2% FCS and 10% FCS) (p<0.05). However, the expression and synthesis of Collagen I was significantly reduced compared to controls. Collagen III expression was partly increased, while Osteocalcin expression was not affected. Discussion. PRP is a source of growth factors such as IGF-1, TGF-β and PDGF-AB. It has a high potential to stimulate cell proliferation, which might have a positive effect in clinical applications. However, the decreased expression and synthesis of Collagen I, the most important Collagen in the tendon, might explain the, to date, less satisfactory clinical results. PRPs might have their potential in chronic situation with pain reducing function rather than in acute healing situations. Further studies are necessary to better understand these mechanisms

Introduction. Ostochondral lesion of the knee is a common cause of chronic knee pain. Arthroscopic treatment with subcondral microfracture is a widespread technique leading to noticeable improvement of knee function and pain. To improve the effectiveness of this treatment options, we thought to add intra (PRF) or post-operative (PRP) growth factors. Platelet rich plasma (PRP) is obtained by centrifugation of the blood to produce a plasma with high concentration of platelets and growth factors. This latter represents a promising method to manage degenerative cartilage lesion and can be used postoperatively to improve clinical results of patients treated arthroscopically. Platelet Rich Fibrin (PRF) has been presented as a second-generation platelet concentrate, and it is used intraoperatively to cover the microfracuteres’ holes. No literature was found about using of PRF intraoperative in association with arthroscopic microfracture technique. The aim of this study is to compare clinical outcomes of the treatment of knee osteochondral lesion using arthroscopic microfracture technique alone or in association with PRF Intraoperative application using “Vivostat” system or with PRP “ReGen Lab” postoperative injection. Patients & Methods. 90 patients with clinical and radiographic evidence of osteochondral lesion of the medial or lateral compartment of the knee were enrolled. All patients received arthroscopic debridement and Microfractures and were randomised into 3 groups: 30 patients received microfractures and intraoperative PRF “Vivostat” injection(Group A), 30 patients received microfracture and 3 intra-articular injections of 5.5 mL PRP “Regen”(Group B), 30 patients received microfracture only. IKDC, KOOS and VAS score were administered to all patients before starting the treatment, at 1, 6 and 12 months from the end of the management. Results. Patients who received microfracture and PRF intraoperative application provided the best outcomes, showing a significant higher clinical scores (P<0.001) compared to the other two groups. Patients underwent PRP postoperative administration reported significant higher score than those undergoing arthroscopic microfracture alone (P<0.005), but lesser than Intraoperative PRF group at 6 months and 1 year follow up. Discussion/Conclusion. Treatment of osteochondral lesions of the knee using microfracture technique significantly improved functional and pain scores from the pre- to postoperatively time in the overall cohort. Intraoperative application of PRF shows significantly better outcome than postoperative PRP injections. However, additional treatment with intra-articular PRP injection as an adjunct to microfracture technique may offer better clinical outcomes over microfracture technique alone

For degenerative osteoarthritis of the knees, a variety of non-surgical management options have been tried from time to time. Medical management, chondroprotective agents, disease modifying drugs, viscosupplimentation etc. to name a few. Arthroscopic knee lavage with saline also has shown good results, with the effect of cleaning the debries from the joint. Growth Factors Rich Plasma (GFRP) or Platelet Rich Plasma (PRP) is an emerging treatment therapy called “ Orthobiologics”. Alfa granules in platelets contain numerous growth factors which enhance tissue recovery dramatically by catalyzing the body's natural healing response. PRP also attracts Mesenchymal Stem Cells, which differentiate into variety of cell types during tissue repair processes & induce the production of new collagen by the fibroblasts, osteoblasts and chondrocytes as per the need of the parent tissue. Knee lavage is done under local anesthesia using single antero-lateral portal. Four liters of saline is used to lavage the knee and at the end of procedure 80 mg. methyl prednisolone is injected. For GFRP injection, 100 cc of patient's blood is double centrifuged in the refrigerated blood component separator centrifuge in the blood bank giving about 15 cc of buffy layer having GFRP. Since Feb. 2010, more than 1000 knees of different grades of osteoarthritis have been injected with GFRP and the results compared with other different treatment options. Results of few different combination therapies are presented in this study. 1. Knee Lavage Vs Autologous GFRP Injection (100+100 cases) 2. Knee Lavage + Autologous GFRP Injection in 1 knee Vs GFRP Injection only in other knee (200+200 Knees) 3. Visco-supplimentation Vs Autologous GFRP Injection. (10+10cases). Results were analyzed up to 1 year as per VAS scale. Knee Lavage clears the joint of the microscopic and macroscopic debris of the cartilage and synovium which are causing chemical and mechanical irritation resulting in the inflammatory cascade. GFRP injection tries to repair the cartilage by the efficacy of the Growth factors contained therein. It has been observed that Knee Lavage and GFRP Injection have almost similar efficacy at 1 year, though knee lavage starts showing its effects early. GFRP therapy has shown better results compared to visco supplimentation at 1 year. Combination of knee lavage with GFRP injection showed much better results than GFRP injection alone and the results are inversely related to the grade of the osteoarthritis. Viscosupplimentation has very short lived efficacy. It's concluded that Knee Lavage followed by GFRP injection gives the best long term results and this pilot project initiated, hopefully will go a long way in future to change the course of the management for osteoarthritis knees at a minimal cost and may obviate the need for Knee arthroplasty if started in early stages of Osteoartrhritis

Summary Statement. An autologous thrombin activated 3-fold PRP, mixed with a biphasic calcium phosphate at a 1mL:1cc ratio, is beneficial for early bone healing in older age sheep. Introduction. The management of bone defects continues to present challenges. Upon activation, platelets secrete an array of growth factors that contribute to bone regeneration. Therefore, combining platelet rich plasma (PRP) with bone graft substitutes has the potential to reduce or replace the reliance on autograft. The simple, autologous nature of PRP has encouraged its use. However, this enthusiasm has failed to consistently translate to clinical expediency. Lack of standardisation and improper use may contribute to the conflicting outcomes reported within both pre-clinical and clinical investigations. This study investigates the potential of PRP for bone augmentation in an older age sheep model. Specifically, PRP dose is controlled to provide clearer indications for its clinical use. Methods. Eighty 11mm diameter defects of 20mm in depth were created in the cancellous bone within the epiphyseal region of the medial proximal tibia and distal femur of twenty five-year-old sheep. The defects were treated with three doses of an autologous thrombin activated PRP combined with a biphasic calcium phosphate (BCP). Activated platelet poor plasma (PPP) and the BCP alone provided reference groups, while the autograft and empty defects served as controls. All animals were sacrificed at four weeks post-operatively for radiographic assessment, micro-computed tomography quantification, histological assessment, histomorphometric quantification of new bone area and bone ingrowth, and weekly fluorochrome bone label quantification. TGF-β1 concentrations were quantified using enzyme-linked immunosorbent assays. Results. The PRP had a 2.9-fold (0.4) increase in platelet concentration, a 0.57-fold (0.09) decrease in leukocytes, and a 0.65-fold (0.11) decrease in fibrinogen. After activation, the PRP had an 8.9-fold (1.5) increase in TGF-β1 serum concentration above baseline. Eleven (11) mm diameter cancellous bone defects in the hind legs of five-year-old sheep do not spontaneously heal within four weeks. PRP dose had a significant effect on the radiographic grade. The highest dose of PRP treatment had a significantly greater micro-CT BV/TV over the BCP alone (PRP: 30.6±1.8%; BCP: 24.5±0.1%). All doses of PRP treatment were significantly greater than the BCP alone for both the histomorphometric new bone area (PRP: 14.5±1.3%; BCP: 9.7±1.5%) and bone ingrowth depth (PRP: 2288±210µm; BCP:1151±268µm). From week two onwards, PRP had a significant effect on the weekly bone ingrowth over BCP, however, autograft had the greatest amount of fluorescently labelled bone within the first three weeks. PRP has a significant effect on the shape and density of osteoblasts within the central region of the defect compared to the BCP alone, however, was not significantly different to autograft. TGF-β1 appeared a better predictor of healing outcomes than platelet concentration, however both had relatively weak correlations (r<.324). Conclusion. PRP induces new bone formation with a dose dependant response at four weeks when used with a biphasic calcium phosphate in older age sheep

Objectives

Mesenchymal stem cells have the ability to differentiate into various cell types, and thus have emerged as promising alternatives to chondrocytes in cell-based cartilage repair methods. The aim of this experimental study was to investigate the effect of bone marrow derived mesenchymal stem cells combined with platelet rich fibrin on osteochondral defect repair and articular cartilage regeneration in a canine model.

Objectives

After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP).

Objectives

In order to ensure safety of the cell-based therapy for bone regeneration, we examined in vivo biodistribution of locally or systemically transplanted osteoblast-like cells generated from bone marrow (BM) derived mononuclear cells.