A Novel Fibrin Matrix Derived from Platelet-Rich Plasma: Protocol and Characterization.

Although fibrin matrices derived from Platelet-Rich Plasma (PRP) are widely used in regenerative medicine, they have some limitations that can hinder their application. Modifying the composition of the PRP-derived fibrin matrix may improve its properties, making it suitable for certain medical uses. Three types of fibrin matrices were obtained: a PRP-derived fibrin matrix (FM), a PRP-derived fibrin matrix with a high fibrinogen content and platelets (FM-HFP) and a PRP-derived fibrin matrix with a high fibrinogen content (FM-HF). The fibrinogen levels, biomechanical properties and cell behavior were analyzed. The presence of platelets in the FM-HFP generated an inconsistent fibrin matrix that was discarded for the rest of the analysis. The fibrinogen levels in the FM-FH were higher than those in the FM (p < 0.0001), with a concentration factor of 6.86 ± 1.81. The values of clotting and swelling achieved using the FM-HF were higher (p < 0.0001), with less clot shrinkage (p < 0.0001). The FM had a significantly higher stiffness and turned out to be the most adherent composition (p = 0.027). In terms of cell viability, the FM-HF showed less cell proliferation but higher live/dead ratio values (p < 0.01). The increased fibrinogen and platelet removal in the FM-HF improved its adhesion and other biomechanical properties without affecting cell viability.

Platelet-Rich Plasma Applications for Achilles Tendon Repair: A Bridge between Biology and Surgery.

Achilles tendon ruptures are very common tendon ruptures and their incidence is increasing in modern society, resulting in work incapacity and months off sport, which generate a need for accelerated and successful therapeutic repair strategy. Platelet-rich plasma (PRP) is emerging as adjuvant human blood-derived constructs to assist Achilles tendon rupture treatment. However, myriad PRP preparation methods in conjunction with poor standardization in the modalities of their applications impinge on the consistent effectiveness of clinical and structural outcomes regarding their therapeutic efficacy. The purpose of this review is to provide some light on the application of PRP for Achilles tendon ruptures. PRP has many characteristics that make it an attractive treatment. Elements such as the inclusion of leukocytes and erythrocytes within PRP, the absence of activation and activation ex vivo or in vivo, the modality of application, and the adjustment of PRP pH can influence the biology of the applied product and result in misleading therapeutic conclusions. The weakest points in demonstrating their consistent effectiveness are primarily the result of myriad PRP preparation methods and the poor standardization of modalities for their application. Selecting the right biological scaffold and applying it correctly to restitutio ad integrum of ruptured Achilles tendons remains a daunting and complex task.

Ultrasound-guided platelet-rich plasma injections for the treatment of osteoarthritis of the hip.

OBJECTIVE: To assess the safety and symptomatic changes of IA injections of platelet-rich plasma (PRP) in patients with OA of the hip. METHODS: Forty patients affected by monolateral severe hip OA were included in the study. Each joint received three IA injections of PRP, which were administered once a week. The primary end point was meaningful pain relief, which was described as a reduction in pain intensity of at least 30% from baseline levels as evaluated by the WOMAC subscale at 6-months post-treatment. The visual analogue scale (VAS) and Harris hip score subscale for pain were used to verify the results. Secondary end points included changes in the level of disability of at least 30% and the percentage of positive responders, i.e. the number of patients that achieved a >30% reduction in pain and disability. RESULTS: Statistically significant reductions in VAS, WOMAC and Harris hip subscores for pain and function were reported at 7 weeks and 6 months (P < 0.05). Twenty-three (57.5%) patients reported a clinically relevant reduction of pain (45%, range 30-71%) as assessed by the WOMAC subscale. Sixteen (40%) of these patients were classified as excellent responders who showed an early pain reduction at 6-7 weeks, which was sustained at 6 months, and a parallel reduction of disability. Side effects were negligible and were limited to a sensation of heaviness in the injection site. CONCLUSIONS: This preliminary non-controlled prospective study supported the safety, tolerability and efficacy of PRP injections for pain relief and improved function in a limited number of patients with OA of the hip.

A randomized clinical trial evaluating plasma rich in growth factors (PRGF-Endoret) versus hyaluronic acid in the short-term treatment of symptomatic knee osteoarthritis.

PURPOSE: This multicenter, double-blind clinical trial evaluated and compared the efficacy and safety of PRGF-Endoret (BTI Biotechnology Institute, Vitoria-Gasteiz, Spain), an autologous biological therapy for regenerative purposes, versus hyaluronic acid (HA) as a short-term treatment for knee pain from osteoarthritis. METHODS: We randomly assigned 176 patients with symptomatic knee osteoarthritis to receive infiltrations with PRGF-Endoret or with HA (3 injections on a weekly basis). The primary outcome measure was a 50% decrease in knee pain from baseline to week 24. As secondary outcomes, we also assessed pain, stiffness, and physical function using the Western Ontario and McMaster Universities Osteoarthritis Index; the rate of response using the criteria of the Outcome Measures for Rheumatology Committee and Osteoarthritis Research Society International Standing Committee for Clinical Trials Response Criteria Initiative (OMERACT-OARSI); and safety. RESULTS: The mean age of the patients was 59.8 years, and 52% were women. Compared with the rate of response to HA, the rate of response to PRGF-Endoret was 14.1 percentage points higher (95% confidence interval, 0.5 to 27.6; P = .044). Regarding the secondary outcome measures, the rate of response to PRGF-Endoret was higher in all cases, although no significant differences were reached. Adverse events were mild and evenly distributed between the groups. CONCLUSIONS: Plasma rich in growth factors showed superior short-term results when compared with HA in a randomized controlled trial, with a comparable safety profile, in alleviating symptoms of mild to moderate osteoarthritis of the knee. LEVEL OF EVIDENCE: Level I, randomized controlled multicenter trial.

Arthroscopic management and platelet-rich plasma therapy for avascular necrosis of the hip.

PURPOSE: The purpose is to describe a noninvasive arthroscopic procedure as an alternative to open surgery for avascular necrosis of the hip. METHODS: Patients with grade I or IIA avascular necrosis of the hip are treated by core decompression performed by drilling under fluoroscopic guidance. Liquid platelet-rich plasma (PRP) is delivered through a trocar, saturating the necrotic area. In more severe conditions, the necrotic bone is decompressed and debrided, through a cortical window at the head-neck junction. A composite graft made of autologous bone and PRP is delivered by impactation through the core decompression track. Fibrin membranes are applied to enhance healing of the head-neck window and arthroscopic portals. Platelet-rich plasma is infiltrated in the central compartment. RESULTS: This arthroscopic approach aids in making diagnosis of the labrum and articular cartilage and permits intra-operative treatment decisions. Visual control permits the precise localization and treatment for the necrotic area allowing cartilage integrity to be preserved. CONCLUSIONS: Arthroscopic management of avascular necrosis of the femoral head is viable and has significant advantages. Clinical studies should justify the theoretical additional benefits of this approach.

Effect of Combined Intraosseous and Intraarticular Infiltrations of Autologous Platelet-Rich Plasma on Subchondral Bone Marrow Mesenchymal Stromal Cells from Patients with Hip Osteoarthritis.

Osteoarthritis (OA) is a debilitating condition that significantly impacts its patients and is closely associated with advancing age and senescence. Treatment with autologous platelet rich plasma (PRP) is a novel approach that is increasingly being researched for its effects. Subchondral bone mesenchymal stromal cells (MSCs) are key progenitors that form bone and cartilage lineages that are affected in OA. This study investigated the changes in subchondral bone MSCs before and after combined intraosseous (IO) and intraarticular (IA) PRP infiltration. Patient bone marrow aspirates were collected from 12 patients (four male, eight female) aged 40-86 years old (median 59.5). MSCs were expanded in standard media containing human serum to passage 1 and analysed for their colony-forming potential, senescence status, and gene expression. Hip dysfunction and Osteoarthritis Outcome Score (HOOS) at baseline and 6 months post second infiltration were used to assess the clinical outcomes; seven patients were considered responders and five non-responders. The number of colony-forming MSCs did not increase in the post treatment group, however, they demonstrated significantly higher colony areas (14.5% higher compared to Pre) indicative of enhanced proliferative capacity, especially in older donors (28.2% higher). Senescence assays also suggest that older patients and responders had a higher resistance to senescent cell accumulation. Responder and non-responder MSCs tended to differ in the expression of genes associated with bone formation and cartilage turnover including osteoblast markers, matrix metalloproteinases, and their inhibitors. Taken together, our data show that in hip OA patients, combined IO and IA PRP infiltrations enhanced subchondral MSC proliferative and stress-resistance capacities, particularly in older patients. Future investigation of the potential anti-ageing effect of PRP infiltrations and the use of next-generation sequencing would contribute towards better understanding of the molecular mechanisms associated with OA in MSCs.

Real-world evidence to assess the effectiveness of platelet-rich plasma in the treatment of knee degenerative pathology: a prospective observational study.

Objective: The present work aims to analyse the effectiveness of platelet-rich plasma (PRP) in degenerative knee pathology based on real-world data and to evaluate possible factors influencing the response to treatment. Methods: In total, 531 cases were analysed collecting data on gender, age, body mass index, pathology location, severity, number of cycles and route of administration. Clinical outcome was evaluated at 6 and 15 months after treatment, using the Knee injury and Osteoarthritis Outcome Score (KOOS) and obtaining percentages of Minimal Clinically Important Improvement (MCII). Blood and PRP samples were randomly tested as a quality control measure to ensure the correct properties. Comparative statistical tests and multivariate regression were performed for the analysis of the variables. Results: The PRP applied had a platelet concentration factor of 1.67, with no leukocytes or erythrocytes. The percentage of patients with MCII at 6 and 15 months after PRP application was 59.32% and 70.62%, respectively. Patients with MCII were younger (p = 0.0246) and with lower body mass index (p = 0.0450). The treatment had a better response in mild/moderate cases than in severe cases (p = 0.0002). Intraosseous PRP application in severe cases improved the effect of intraarticular PRP (p = 0.0358). The application of a second cycle of PRP only improved the response in patients without MCII at 6 months (p = 0.0029), especially in mild/moderate cases (p = 0.0357). Conclusion: The applications of PRP in degenerative knee pathologies is an effective treatment, but this effectiveness nonetheless depends on several variables. Real-world data can complement that from clinical trials to provide valuable information.

Custom 3D-Printed Cutting Guides for Femoral Osteotomy in Rotational Malalignment Due to Diaphyseal Fractures: Surgical Technique and Case Series.

Femoral shaft fractures are one of the most common injuries in trauma patients. The gold standard treatment consists of closed reduction and intramedullary nailing, providing a high fracture healing rate and allowing early mobilization. However, rotational malalignment is a well-known complication following this procedure, and excessive femoral anteversion or femoral retroversion can trigger functional complaints. In order to achieve the ideal degree of femoral rotation, a 3D planning and printing cutting guides procedure was developed to correct femoral malrotation. A patient series with malalignment after a femoral diaphyseal fracture was operated on with the customized guides and evaluated in this study. Computed tomography scans were performed to accurately determine the number of degrees of malrotation, allowing the design of specific and personalized surgical guides to correct these accurately. Once designed, they were produced by 3D printing. After surgery with the customized guides to correct femoral malrotation, all patients presented a normalized anteversion angle of the femur (average -10.3°, range from -5° to -15°), according to their contralateral limb. These data suggest that the use of customized cutting guides for femoral osteotomy is a safe and reproducible surgical technique that offers precise results when correcting femoral malrotation.

Intraosseous infiltrations of Platelet-Rich Plasma for severe hip osteoarthritis: A pilot study.

OBJECTIVE: Addressing the subchondral bone through intraosseous infiltrations of Platelet-Rich Plasma (PRP) may improve the effectiveness of this technique for severe hip osteoarthritis (HOA). METHODS: Forty patients with HOA degree 2 and 3 according to the Tönnis scale were recruited for this study. They were susceptible to a total hip arthroplasty, without response to previous treatment based on intraarticular infiltrations of PRP. Patients received a combination of intraosseous injections into the acetabulum and the femoral head, as well as intraarticular PRP infiltrations. The clinical outcome was evaluated at 2, 6 and 12 months using the Hip Osteoarthritis Outcome Score (HOOS) and the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index. RESULTS: At 2, 6 and 12 months, patients had significant pain improvement according to HOOS pain, WOMAC pain, and VAS scores. After the treatment, the percentage of patients with minimal clinically important improvement was 40% (16 over 40 patients) at 2 months, 37.5% (15 over 40) at 6 months, and 40% (16 over 40) at 12 months. Conclusion: The combination of intra-articular and intra-osseous infiltrations of PRP showed a pain reduction and improvement in hip joint functionality up to 12 months in patients with severe HOA, with no severe adverse effects.

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

OBJECTIVE: Assessing the therapeutic effects of a combination of intra-articular and intra-osseous infiltrations of platelet-rich plasma (PRP) to treat severe knee osteoarthritis (KOA) using intra-articular injections of PRP as the control group. DESIGN: In this observational study, 60 patients suffering from severe KOA were treated with intra-articular infiltrations of PRP (IA group) or with a combination of intra-osseous and intra-articular infiltrations of PRP (IO group). Both groups were matched for sex, age, body mass index, and radiographic severity (III and IV degree according to Ahlbäck scale). Clinical outcome was evaluated at 2, 6, and 12 months, using the Knee injury and Osteoarthritis Outcome Score (KOOS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaires. RESULTS: At 2, 6 and 12 months after treatment, IO group had a significant improvement in all KOOS and WOMAC subscales ( P < 0.05). On the contrary, patients of the IA group did not improve in any of the scores. Sixteen out of 30 IO group patients showed minimal clinically important improvement (MCII) whereas 8 out of 30 IA group patients showed this response at 6 months (26.7%; 95% CI -0.4 to 49.9; P = 0.037). At 12 months, 14 patients of IO group and 5 patients of the IA group showed MCII (30%; 95% CI 4.3 to 51.9; P = 0.013). No differences between groups were observed at 2 months. CONCLUSIONS: PRP intra-articular injections in severe KOA were not effective and did not provide any benefit. Combination of intra-articular and intra-osseous infiltrations of PRP was not clinically superior at 2 months, but it showed superior clinical outcomes at 6 and 12 months when compared with intra-articular injections of PRP.

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

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

Intraosseous Infiltration of Platelet-Rich Plasma for Severe Hip Osteoarthritis.

This work describes a technique of platelet-rich plasma (PRP) infiltration for the treatment of severe hip osteoarthritis (OA). Although the results achieved with intra-articular infiltrations of PRP are promising, they may be insufficient in the long-term for severe hip OA. The technique consists of a combined intra-articular and intraosseous infiltration of PRP to reach all joint tissues, especially the subchondral bone, and hence facilitate a greater distribution of PRP. Diagnosis is based on clinical and radiographic findings, and patients with grade III OA according to the Tönnis scale, as well as patients who have not responded to conventional treatment, are considered candidates for this technique. After an ultrasound-guided intra-articular PRP infiltration is performed, 2 intraosseous infiltrations are conducted with a fluoroscope; the first injection is applied into the acetabulum and the second into the femoral head. However, this technique presents more difficulty than the conventional administration, so it is necessary to consider several aspects described in this work.

Application of 3D technology and printing for femoral derotation osteotomy: case and technical report.

In some surgical techniques like femoral derotation osteotomy, accuracy is a key factor that often is not optimal because of the lack of appropriate technology. 3D printing is emerging in many professional areas and its use in the medical field may enhance the results of certain surgeries. This case describes a patient who underwent an intramedullary nail fixation to treat a femoral shaft fracture. After nine months, the patient presented hip pain and "in toe" walking caused by a malrotation produced during the surgery. To address the consequent femoral derotation osteotomy, 3D technology was used throughout the whole process. A 3D model of the patient's femur was created to conduct a real and accuracy assessment of femoral anteversion. Then, a customized surgical guide was designed and printed to ensure the proper alignment during surgery. Given the success of this surgery, 3D printing can be considered a quick and inexpensive tool to improve surgical results.

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

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

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

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

Platelet rich plasma and knee surgery.

In orthopaedic surgery and sports medicine, the knee joint has traditionally been considered the workhorse. The reconstruction of every damaged element in this joint is crucial in achieving the surgeon's goal to restore the knee function and prevent degeneration towards osteoarthritis. In the last fifteen years, the field of regenerative medicine is witnessing a boost of autologous blood-derived platelet rich plasma products (PRPs) application to effectively mimic and accelerate the tissue healing process. The scientific rationale behind PRPs is the delivery of growth factors, cytokines, and adhesive proteins present in platelets and plasma, as well as other biologically active proteins conveyed by the plasma such as fibrinogen, prothrombin, and fibronectin; with this biological engineering approach, new perspectives in knee surgery were opened. This work describes the use of PRP to construct and repair every single anatomical structure involved in knee surgery, detailing the process conducted in ligament, meniscal, and chondral surgery.

Intraosseous infiltration of platelet-rich plasma for severe knee osteoarthritis.

We describe a new technique of platelet-rich plasma (PRP) infiltration for the treatment of severe knee osteoarthritis. PRP intra-articular infiltration is a promising treatment for knee osteoarthritis, but it still has some limitations in high-degree osteoarthritis. Diagnosis of osteoarthritis is based on clinical and radiographic findings, and patients with grade III or IV knee tibiofemoral osteoarthritis based on the Ahlbäck scale are considered candidates for this technique. The technique consists of performing intraosseous infiltration of PRP into the subchondral bone, which acts on this tissue and consequently on cartilage-bone communication. Although the intraosseous injection hinders the conventional knee intra-articular infiltration, it allows an extension of the range of action of the PRP, which acts directly on the subchondral bone, which is involved in the progression of osteoarthritis. Thus this technique involves a new administration of PRP that can delay knee arthroplasty; moreover, it can be applied for not only severe osteoarthritis but also other pathologies in which the subchondral bone is critical in the etiology, such as necrosis and osteochondral lesions.

A less-invasive technique for capsular management during hip arthroscopy for femoroacetabular impingement.

The aim of this work is to describe a new arthroscopic technique for the treatment of femoroacetabular impingement that allows a complete articular joint view with maximum protection of the capsuloligamentous complex. This arthroscopic technique avoids injury to the capsuloligamentous complex, preventing the risk of postoperative instability. The diagnosis of femoroacetabular impingement was based on clinical and radiographic grounds. An alpha angle greater than 50° was considered pathologic. In this technique, the use of intra-articular devices (retractors) allows us to separate the capsular tissue from the femoral head-neck junction and mobilize the capsule, achieving an adequate joint view without performing a capsulotomy and, consequently, avoiding the complications of capsular damage.