Nonunions treated with autologous preparation rich in growth factors

Orthobiologics in delayed union and non-union of adult long bones fractures: A systematic review

Background

Fracture healing poses a significant challenge in orthopedics. Successful regeneration of bone is provided by mechanical stability and a favorable biological microenvironment. This systematic review aims to explore the clinical application of orthobiologics in treating aseptic delayed union and non-union of long bones in adults.

Methods

A systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Three databases were explored, with no date restrictions, using keywords related to orthobiologics and delayed union and non-union. Eligible studies included human clinical studies in English, with available full texts, examining orthobiologics such as platelet-rich plasma (PRP), mesenchymal stem cells (MSCs), and bone morphogenetic protein (BMPs) for treating aseptic delayed unions and non-unions in adults. Animal studies, in vitro research, and studies on non-unions due to congenital defects, tumors or infections were excluded.

Results

The initial search identified 9417 studies, with 20 ultimately included in the review. These studies involved 493 patients affected by non-union and 256 patients affected by delayed union, with an average age respectively of 40.62 years and 41.7 years. The mean follow-up period was 15.55 months for non-unions and 8.07 months for delayed unions. PRP was the most used orthobiologic, and outcomes were evaluated through time to union, functional scores, and clinical examinations. The results indicated that orthobiologics, especially PRP, tended to yield better outcomes compared to surgical procedures without biological factors.

Conclusion

This systematic review suggests that orthobiologics, such as PRP, BMPs, and MSCs, can be effective and safe in the management of delayed union and non-union fractures. These biological treatments have the potential to improve union rates, reduce healing times, and enhance functional outcomes in patients with non-union fractures. Further research is essential to refine treatment protocols and determine the most suitable orthobiologic for specific patient populations and fracture types.

Advances with Platelet-Rich Plasma for Bone Healing

Despite significant advances in the understanding and delivery of osteosynthesis, fracture non-union remains a challenging clinical problem in orthopaedic surgery. To bridge the gap, basic science characterization of fracture healing provides a platform to identify and target biological strategies to enhance fracture healing. Of immense interest, Platelet-rich plasma (PRP) is a point of care orthobiologic that has been extensively studied in bone and soft tissue healing given its relative ease of translation from the benchtop to the clinic. The aim of this narrative review is to describe and relate pre-clinical in-vitro and in-vivo findings to clinical observations investigating the efficacy of PRP to enhance bone healing for primary fracture management and non-union treatment. A particular emphasis is placed on the heterogeneity of PRP preparation techniques, composition, activation strategies, and delivery. In the context of existing data, the routine use of PRP to enhance primary fracture healing and non-union management cannot be supported. However, it is acknowledged that extensive heterogeneity of PRP treatments in clinical studies adds obscurity; ultimately, refinement (and consensus) of PRP treatments for specific clinical indications, including repetition studies are warranted.

Treatment of Aneurysmal Bone Cyst with Endoscopic Resection and Bone Allograft with Platelet-Rich Plasma: A Case Report

An aneurysmal bone cyst (ABC) is a rare bone tumor usually observed in long bones. The surgical treatment of this pathology is often related to high recurrence rates, so novel biological techniques can help to enhance tissue regeneration and bone consolidation. We present a case of a patient with ABC of the calcaneus treated with an endoscopic resection followed by grafting with an autologous-based matrix composed of allograft bone chips and autologous platelet-rich plasma (PRP) in semisolid and liquid states. Patient demonstrated excellent defect filling in both magnetic resonance imaging and radiologic exams and returned to pre-injury activity with no recurrence at 2 years follow-up. Endoscopic curettage together with allograft bone and autologous PRP is effective in treating ABC patients and could be a good adjuvant treatment to prevent reinjury and enhance consolidation.

Ultrasound-guided injection of platelet-rich plasma or cord blood platelet-rich plasma in nonunion: a randomized controlled trial

Aim: To compare the ability of autologous platelet-rich plasma (PRP) and cord blood PRP (PRPc) to accelerate bone healing. Patients & methods: 71 patients with mechanically stable nonunion were treated weekly (3 consecutive weeks) with ultrasound-guided percutaneous injections of PRP or PRPc in a controlled randomized clinical trial. The primary outcome was healing (12 months) and secondary outcomes were radiological evolution (2 and 6 months) and changes in pain intensity (6 months). Results & conclusion: Bone consolidation was assessed over time without significant differences between PRP and PRPc treatment. In patients with persistent nonunion, pain perception decreased more after PRP treatment. PRPc appears to be a valid alternative when specific clinical conditions suggest avoiding the use of autologous blood products.

Effectiveness of plasma rich in growth factors in the management of chronic spinal pain: a case series of 32 patients

Background: This prospective, case-series study aimed to assess the clinical effectiveness of plasma rich in growth factors (PRGF) in patients with chronic low back pain (LBP) and to identify the features of the responsive patients. Materials & methods: PRGF was injected into the intervertebral disc, epidural space and/or facet and sacroiliac joints of 32 patients with chronic LBP. The efficacy of the treatment was assessed by algo-functional scores after 3 and 6 months. Results: Overall, the patients did not ameliorate after PRGF treatment, although eight patients showed an algo-functional improvement. They were mainly males treated at two sites who were younger, less sedentary and with fewer musculoskeletal co-morbidities than the nonresponders. Conclusion: PRGF is a potential treatment in a specific subpopulation of difficult-to-treat patients affected by chronic LBP.

The role of Platelet Rich Plasma and other orthobiologics in bone healing and fracture management: A systematic review

BACKGROUND

Treatment of large bone defects and fracture healing complications (delayed and non-union) presents a substantial challenge for orthopaedic surgeons. Given that bone healing requires mechanical stability as well as a favourable biological microenvironment, orthobiologics such as Platelet-Rich Plasma (PRP) may have a significant clinical role to play.

AIMS

To perform a systematic review of the available literature to assess the clinical effect of PRP, with or without other orthobiologics, on bone healing.

METHOD

Two independent reviewers performed the literature search based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Clinical studies of any evidence, assessing effect of PRP with or without other orthobiologics on bone healing, were included. A qualitative analysis was carried out on the clinical and radiological outcomes reported.

RESULT

27 articles with 1631 patients (mean age = 43.56, 57.1% male, mean follow-up = 17.27 months) were included in the qualitative. Of the 27 studies, 13 dealt with fracture complications (delayed or non-unions), 7 with acute fracture healing, 4 with tibial osteotomies and lengthening procedures and 3 with lumbar spine pathology. 18/27 studies showed a clinical benefit of PRP, 8/27 showed no significant effect, and 1/27 showed a worse outcome with PRP.

CONCLUSION

Our review suggests PRP may play a clinical role in bone healing but further randomised controlled trials (RCTs) using standardised outcomes should be performed to establish its efficacy.

The Use of Platelet-Rich Plasma (PRP) for the Management of Non-union Fractures

PURPOSE OF REVIEW

The treatment of non-union fractures represents a significant challenge for orthopaedic surgeons. In recent years, biologic agents have been investigated and utilised to support and improve bone healing. Among these agents, platelet-rich plasma (PRP) is an emerging strategy that is gaining popularity. The aim of this review is to evaluate the current literature regarding the application and clinical effectiveness of PRP injections, specifically for the treatment of non-union fractures.

RECENT FINDINGS

The majority of published studies reported that PRP accelerated fracture healing; however, this evidence was predominantly level IV. The lack of randomised, clinical trials (level I-II evidence) is currently hampering the successful clinical translation of PRP as a therapy for non-union fractures. This is despite the positive reports regarding its potential to heal non-union fractures, when used in isolation or in combination with other forms of treatment. Future recommendations to facilitate clinical translation and acceptance of PRP as a therapy include the need to investigate the effects of administering higher volumes of PRP (i.e. 5-20 mL) along with the requirement for more prolonged (> 11 months) randomised clinical trials.

The effect of platelet-rich plasma on fracture healing in long-bone pseudoarthrosis

PURPOSE

The aim of this study was to investigate the effects of platelet-rich plasma (PRP) on fracture union rate and fracture union time in pseudoarthrosis surgery and to evaluate the clinical and functional results of the patients.

METHODS

The patients who were undergone pseudoarthrosis surgery between 2011 and 2014 were evaluated retrospectively. Twenty-four patients were included in the study. Patients were divided into two groups with used PRP and not used PRP during surgery. There were 14 patients in the PRP group and 10 patients in the control group. The two groups were compared in terms of demographic characteristics, fracture union time, and functional scores of the Lower Extremity Functional Scale and Upper Extremity Functional Index.

RESULTS

Fractures were healed in both groups, and no complications were encountered. A statistically significant difference was found between the two groups in terms of fracture union time. The mean time of union was 5.3 months in the PRP group and 11.3 months in the control group (p: 0.000). There was no statistically significant difference between the two groups in terms of functional scores (p: 0.250).

CONCLUSION

As a result of our study, we concluded that PRP is an effective and safe method in pseudoarthrosis surgery that reduces fracture union time. Controlled studies with more patient numbers are needed.

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.

Autologous fibrin scaffolds: When platelet- and plasma-derived biomolecules meet fibrin

The healing of vascularized mammalian tissue injuries initiate with hemostasis and clotting as part of biological defense system leading to the formation of a fibrin clot in which activated platelets are trapped to quickly stop bleeding and destroy microbials. In order to harness the therapeutic potential of biomolecules secreted by platelets and stemmed from plasma, blood deconstruction has allowed to yield autologous platelet-and plasma-derived protein fibrin scaffold. The autologous growth factors and microparticles stemmed from platelets and plasma, interact with fibrin, extracellular matrix, and tissue cells in a combinatorial, synergistic, and multidirectional way on mechanisms governing tissue repair. This interplay will induce a wide range of cell specifications during inflammation and repair process including but not limited to fibrogenesis, angiogenesis, and immunomodulation. As biology-as-a-drug approach, autologous platelet-and plasma-derived protein fibrin scaffold is emerging as a safe and efficacious natural human-engineered growth factor delivery system to repair musculoskeletal tissues, and skin and corneal ulcers and burns. In doing so, it acts as therapeutic agent not perfect but close to biological precision. However, this autologous, biocompatible, biodegradable, and long in vivo lasting strategy faces several challenges, including its non-conventional single dose-response effect, the lack of standardization in its preparation and application, and the patient's biological features. In this review, we give an account of the main events of tissue repair. Then, we describe the procedure to prepare autologous platelet-and plasma-derived protein fibrin scaffolds, and the rationale behind these biomaterials, and finally, we highlight the significance of strategic accuracy in their application.

To evaluate the role of platelet-rich plasma in healing of acute diaphyseal fractures of the femur

PURPOSE

New research is focusing on the use of autologous growth factors to increase the effect of bone fracture healing while decreasing the amount of healing time for the patient. Platelets have been demonstrated to be the natural storage vessel for several growth factors and cytokines that promote blood coagulation, tissue repair, and the process of bone mineralization. The present study aims to evaluate the role of platelet-rich plasma (PRP) in healing of acute femoral shaft fractures radiologically. We hypothesize that it provides artificial hematoma and releases various growth factors.

METHODS

This prospective randomized study was carried out in 72 patients of traumatic fracture of the femoral shaft operated with interlocking nails (closed or open). Patients were divided into two groups: study group A (n = 33) treated with intramedullary nailing & PRP injection/gel application in the same setting; and control group B (n = 39) treated with intramedullary nailing without PRP application. Both groups were further divided into two subgroups. Study group included subgroup A1 (n = 14) operated with closed intramedullary nailing and PRP injection at the fracture site under radiological control, and subgroup A2 (n = 19) operated with open intramedullary nailing and PRP gel along with fibrin membrane application at the fracture site; while control group included subgroup B1 (n = 16) operated with closed intramedullary nailing, and subgroup B2 (n = 23) operated with open intramedullary nailing. Radiological assessment of fracture healing was done by measuring the cortex to callus ratio every month till union at 6 months.

RESULTS

Measurements of mean cortex to callus ratio revealed significant difference between the groups A & B at third and fourth months. Measurements of mean cortex to callus ratio did not reveal significant difference between the subgroups at first and sixth months. A statistically significant difference was observed between subgroups A1 & B2 and B1 & B2 at the second month; between subgroups A1 & B2, A2 & B2 and B1 & B2 at the third month; and between subgroups A1 & B2 at fourth and fifth months.

CONCLUSION

PRP has no effect on femoral shaft fracture healing treated with closed intramedullary nailing. However, PRP and matrix scaffold provided by fibrin membrane may provide an artificial hematoma effect in the initial phase of healing in open or failed closed intramedullary nailing.

Platelet-rich plasma for the treatment of bone defects: from pre-clinical rational to evidence in the clinical practice. A systematic review

PURPOSE

The treatment of large bone defects represents a significant challenge for orthopaedic surgeons. In recent years, biologic agents have also been used to further improve bone healing. Among these, platelet-rich plasma (PRP) is the most exploited strategy. The aim of the present study was to systematically review the available literature to identify: 1) preclinical in-vivo results supporting the rational of PRP use for bone healing; 2) evidence from the clinical practice on the actual clinical benefit of PRP for the treatment of fractures and complications such as delayed unions and non-unions.

METHODS

A systematic review of the literature was performed on the application of PRP in bone healing, using the following inclusion criteria: pre-clinical and clinical reports of any level of evidence, written in English language, published in the last 20 years (1996-2016), on the use of PRP to stimulate long-bone defect treatment, with focus on fracture and delayed/non-unions healing.

RESULTS

The search in the Pubmed database identified 64 articles eligible for inclusion: 45 were preclinical in-vivo studies and 19 were clinical studies. Despite the fact that the overall pre-clinical results seem to support the benefit of PRP in 91.1 % of the studies, a more in depth analysis underlined a lower success rate, with a positive outcome of 84.4 % in terms of histological analysis, and even lower values considering radiological and biomechanical results (75.0 % and 72.7 % positive outcome respectively). This was also mirrored in the clinical literature, where the real benefit of PRP use to treat fractures and non-unions is still under debate.

CONCLUSION

Overall, the available literature presents major limitations in terms of low quality and extreme heterogeneity, which hamper the possibility to optimize PRP treatment and translate it into a real clinical benefit despite positive preclinical findings on its biological potential to favour bone healing.

Pain in donor site after BTB-ACL reconstruction with PRGF: a randomized trial

INTRODUCTION

Anterior cruciate ligament (ACL) tears are highly incident injuries in young athletes within our work area. The use of the patellar graft, despite being the treatment of choice, presents post-operative problems such as anterior knee pain, which limits its use and leads to preference being taken for alternative grafts. Our aim was to evaluate if the application of PRGF reduces anterior knee pain in donor site in BTB-ACL reconstruction.

MATERIALS AND METHODS

43 patients were included in the double-blinded and randomized clinical trial comparing two patient groups who underwent ACL reconstruction using patellar tendon graft, comparing anterior knee pain with and without the application of PRGF at the donor site after harvesting the graft.

RESULTS

The PRGF group showed decreased donor site pain in comparison to the control group, with significant differences in the first two months of follow-up.

CONCLUSION

The application of PRGF decreased donor site pain compared to the control group.

A new strategy to tackle severe knee osteoarthritis: Combination of intra-articular and intraosseous injections of Platelet Rich Plasma

INTRODUCTION

Knee osteoarthritis (KOA) is a mechanically induced, cytokine and enzyme-mediated disorder involving all the joint tissue of the knee. Rebuilding a physiological-homeostatic network at the tissue level following knee organ failure, such as in severe KOA, is a daunting task with therapeutic targets encompassing the articular cartilage, synovium and subchondral bone. Intraarticular infiltration of plasma rich in growth factors (PRP) has emerged as a promising symptomatic approach, although it is insufficient to reach the subchondral bone.

AREAS COVERED

This review addresses current molecular and cellular data in joint homeostasis and osteoarthritis pathophysiology. In particular, it focuses on changes that subchondral bone undergoes in knee osteoarthritis and evaluates recent observations on the crosstalk among articular cartilage, subchondral bone and synovial membrane. In addition, we review some mechanistic aspects that have been proposed and provide the rationale for using PRP intraosseously in KOA.

EXPERT OPINION

The knee joint is a paradigm of autonomy and connectedness of its anatomical structures and tissues from which it is made. We propose an innovative approach to the treatment of severe knee osteoarthritis consisting of a combination of intraarticular and intraosseous infiltrations of PRP, which might offer a new therapeutic tool in KOA therapy.

Healing of donor site in bone-tendon-bone ACL reconstruction accelerated with plasma rich in growth factors: a randomized clinical trial

PURPOSE

To determine whether the use of plasma rich in growth factors accelerates healing of the donor site in bone-tendon-bone anterior cruciate ligament (ACL) reconstruction (patellar graft). The use of the patellar graft presents post-operative problems such as anterior knee pain, which limits its use and leads to preference being taken for alternative grafts.

METHODS

A double-blind, randomized, clinical trial was performed comparing two groups of patients who underwent ACL reconstruction using patellar tendon graft and comparing the use of plasma rich in growth factors at the donor site after graft harvest in terms of local regeneration by ultrasound assessment.

RESULTS

The plasma rich in growth factors group shows earlier donor site regeneration in comparison with the control group (2 months earlier), with significant differences in the first 4 months of the follow-up.

CONCLUSION

The application of plasma rich in growth factors shows accelerated tissue regeneration processes with respect to the control group. This fact, together with the previously published with similar conclusions, can create a knowledge basis in order to set out new recovery guidelines following ACL reconstruction.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

Why menisci show higher healing rate when repaired during ACL reconstruction? Growth factors release can be the explanation

PURPOSE

Healing rate of meniscus repair is higher when the suture is associated with anterior cruciate ligament reconstruction. A possible explanation can be a different pattern of release of growth factors between anterior cruciate ligament reconstruction and isolated meniscus surgery. Hypothesis of this study is that the concentrations of bFGF, TGF-β and platelet-derived growth factor (PDGF) in joint fluid, immediately after single-bundle anterior cruciate ligament reconstruction and arthroscopic partial meniscectomy, can be different.

METHODS

Twenty consecutive patients underwent partial medial meniscectomy and twenty consecutive patients underwent single-bundle anterior cruciate ligament reconstruction with hamstring grafts were enrolled in the study. Thirty minutes after the end of the surgical procedure, a sample of joint fluid, as well of venous blood, was collected from all the patients. Concentrations of growth factors were determined by enzyme-linked immunosorbent assay.

RESULTS

The peripheral blood concentration of TGF-β, bFGF and PDGF was comparable between partial meniscectomy and anterior cruciate ligament reconstruction groups. No differences between the two surgical techniques were also found in term of TGF-β and bFGF joint fluid concentration, whereas joint PDGF concentration of anterior cruciate ligament reconstruction patients was significantly higher than the one found in partial meniscectomy patients.

CONCLUSIONS

A significant growth factors release was detected in the knee joint during arthroscopic surgery. PDGF concentration was significantly higher in anterior cruciate ligament reconstructed knee than in the meniscectomy group. PDGF can play an important role enhancing the healing response of meniscus suture and can be one of the biological reasons of the higher meniscal healing rate in anterior cruciate ligament reconstructed knee.

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.

Platelet-rich plasma in bone regeneration: engineering the delivery for improved clinical efficacy

Human bone is a tissue with a fairly remarkable inherent capacity for regeneration; however, this regenerative capacity has its limitations, and defects larger than a critical size lack the ability to spontaneously heal. As such, the development and clinical translation of effective bone regeneration modalities are paramount. One regenerative medicine approach that is beginning to gain momentum in the clinical setting is the use of platelet-rich plasma (PRP). PRP therapy is essentially a method for concentrating platelets and their intrinsic growth factors to stimulate and accelerate a healing response. While PRP has shown some efficacy in both in vitro and in vivo scenarios, to date its use and delivery have not been optimized for bone regeneration. Issues remain with the effective delivery of the platelet-derived growth factors to a localized site of injury, the activation and temporal release of the growth factors, and the rate of growth factor clearance. This review will briefly describe the physiological principles behind PRP use and then discuss how engineering its method of delivery may ultimately impact its ability to successfully translate to widespread clinical use.

Current state and use of biological adhesives in orthopedic surgery

Bone and tissue adhesives are common and beneficial supplements to standard methods of musculoskeletal tissue suture repair. Knowledge and development of biologically derived or inspired adhesives useful in orthopedic surgery are rapidly advancing. Recent literature demonstrates the increased adjunct or primary use of biological adhesives in the repair of musculoskeletal soft tissues, chondral fractures, and osteochondral fractures. Adhesives offer more benefits and enhancements to tissue healing than current fixation methods afford, including improved biocompatibility, resorbability, and non-immunogenicity. Further investigation is required to determine the extent of the role that these bioadhesives can play in orthopedic surgery. The largest group of biologically derived adhesives and sealants is fibrin sealants, which include first- and second-generation commercially available fibrin sealants, autologous fibrin sealants, and variants. Other groups include gelatin-resorcin aldehydes, protein-aldehyde systems, collagen-based adhesives, polysaccharide- based adhesives, mussel adhesive proteins, and various biologically inspired or biomimetic glues. Potential uses include applications in orthopedic-related blood conservation, arthroplasty, articular cartilage disorders, sports medicine, spine surgery, trauma, and tumors. The development of an adhesive with universal application is likely unfeasible, given the unique characteristics of various musculoskeletal tissues. However, the literature demonstrates the overall underuse of adhesives and indicates the rising probability of the development of a successful variety of bioadhesives for use in orthopedic surgery. As a result of reading this article, physicians should be able to: 1. Describe the difference between adhesives and sealants. 2. Recognize fibrin adhesives commonly used in practice today and identify other biological adhesives with rising potential. 3. Analyze how fibrin sealants work relative to fibrin and fibrinogen. 4. Identify anatomical areas and techniques in which fibrin sealants are used.

Application of Platelet-Rich Plasma to Disorders of the Knee Joint

IMPORTANCE

The promising therapeutic potential and regenerative properties of platelet-rich plasma (PRP) have rapidly led to its widespread clinical use in musculoskeletal injury and disease. Although the basic scientific rationale surrounding PRP products is compelling, the clinical application has outpaced the research.

OBJECTIVE

The purpose of this article is to examine the current concepts around the basic science of PRP application, different preparation systems, and clinical application of PRP in disorders in the knee.

EVIDENCE ACQUISITION

A systematic search of PubMed for studies that evaluated the basic science, preparation and clinical application of platelet concentrates was performed. The search used terms, including platelet-rich plasma or PRP preparation, activation, use in the knee, cartilage, ligament, and meniscus. Studies found in the initial search and related studies were reviewed.

RESULTS

A comprehensive review of the literature supports the potential use of PRP both nonoperatively and intraoperatively, but highlights the absence of large clinical studies and the lack of standardization between method, product, and clinical efficacy. Conclusions and Relevance. In addition to the call for more randomized, controlled clinical studies to assess the clinical effect of PRP, at this point, it is necessary to investigate PRP product composition and eventually have the ability to tailor the therapeutic product for specific indications.

Research progress in the mechanism of effect of PRP in bone deficiency healing

Platelet-rich plasma (PRP) therapy is a recently developed technique that uses a concentrated portion of autologous blood to try to improve and accelerate the healing of various tissues. There is a considerable interest in using these PRP products for the treatment used in bone deficiency healing. Because PRP products are safe and easy to prepare and administer, there has been increased attention toward using PRP in numerous clinical settings. The benefits of PRP therapy appear to be promising, and many investigators are exploring the ways in which this therapy can be used in the clinical setting. At present, the molecular mechanisms of bone defect repair studies have focused on three aspects of the inflammatory cytokines, growth factors and angiogenic factors. The role of PRP works mainly through these three aspects of bone repair. The purpose of this paper is to review the current evidence on the mechanism of the effect of PRP in bone deficiency healing.

Recommendations and considerations for the use of biologics in orthopedic surgery

Reconstruction of extensive bone defects remains technically challenging and has considerable medical and financial impact on our society. Surgical procedures often require a bone/substitute graft to enhance and accelerate bone repair. Bone autografts are associated with morbidity related to bone harvesting and are limited in quantity. Alternatively, bone allografts expose the patient to the risk of transmission of infectious disease. Synthetic bone graft substitutes, such as calcium sulfates, hydroxyapatite, tricalcium phosphate, and combinations, circumvent some of the disadvantages of auto- and allografts, but have limited indications. Biomedical research has made possible the stimulation of the body's own healing mechanisms, either by delivering exogenous growth factors locally, or by stimulating their local production by gene transfer. Among all known factors having osteoinductive properties, only two bone morphogenetic proteins (for specific indications) and demineralized bone matrix have been approved for clinical use. In addition, ongoing research is exploring the efficacy of cell therapy and tissue engineering. The present report examines the composition, biological properties, indications, clinical experience and regulations of several of the biotherapeutics employed for bone reconstruction.

Platelet-rich plasma treatment in symptomatic patients with knee osteoarthritis: preliminary results in a group of active patients

Background:

With increasing frequency, platelet-rich plasma (PRP) preparations have been used to treat cartilage lesions to regenerate tissue homeostasis and retard the progression of knee osteoarthritis (OA).

Purpose:

To determine the effectiveness of intra-articular PRP injections in active patients with knee OA and to evaluate clinical outcomes in patients with and without previous surgical treatment for cartilage lesions.

Study Design:

Case series.

Materials and Methods:

Fifty patients with knee OA were followed for a minimum of 12 months. All were treated with 2 intra-articular injections of autologous PRP. Twenty-five patients had undergone a previous operative intervention for cartilage lesions, whereas 25 had not. Operated patients had undergone either cartilage shaving or microfracture. Multiple evaluative scores were collected at pretreatment and at 6 and 12 months posttreatment. The required sample of patients was determined beforehand by using statistical power analysis; International Knee Documentation Committee (subjective) score was defined as the primary parameter. A P value of less than 0.05 was considered statistically significant. General linear model–repeated measure test evaluated within-time improvement for each variable for all patients. Post hoc test with Bonferroni adjustment for multiple comparisons was performed to investigate the significance in improvement within time evaluations for each variable for the total sample. The differences in improvement between operated and nonoperated patients were also investigated, as were those between sexes.

Results:

All patients showed significant improvement in all scores at 6 and 12 months (P < 0.01) and returned to previous activities. No significant difference in improvement was found between the evaluated subgroups (P < 0.01).

Conclusions:

The PRP treatment showed positive effects in patients with knee OA. Operated and nonoperated patients showed significant improvement by means of diminishing pain and improved symptoms and quality of life.

Clinical Relevance:

There are only a few studies of PRP treatment for cartilage on osteoarthritic knees. Different PRP products might be more or less appropriate to treat different types of tissues and pathologies. The clinical efficacy of PRP remains under debate, and a standardized protocol has not yet been established.

Platelet-rich plasma: the PAW classification system

Platelet-rich plasma (PRP) has been the subject of hundreds of publications in recent years. Reports of its effects in tissue, both positive and negative, have generated great interest in the orthopaedic community. Protocols for PRP preparation vary widely between authors and are often not well documented in the literature, making results difficult to compare or replicate. A classification system is needed to more accurately compare protocols and results and effectively group studies together for meta-analysis. Although some classification systems have been proposed, no single system takes into account the multitude of variables that determine the efficacy of PRP. In this article we propose a simple method for organizing and comparing results in the literature. The PAW classification system is based on 3 components: (1) the absolute number of Platelets, (2) the manner in which platelet Activation occurs, and (3) the presence or absence of White cells. By analyzing these 3 variables, we are able to accurately compare publications.

The role of platelet rich plasma in musculoskeletal science

The idea of using platelet rich plasma (PRP) in medicine has been around since the 1970s. It is only more recently that its use has been employed in the area of musculoskeletal science. Platelet rich plasma in this area has received much media attention being used by many celebrity sports athletes for musculoskeletal injuries. Therefore it is important for the musculoskeletal practitioner to be aware of the concepts surrounding its use and application. In this article we cover what platelet rich plasma is, how it is prepared and administered, its potential clinical application, and what the current literature discusses in the various areas of musculoskeletal science.

Platelet-rich plasma for calcific tendinitis of the shoulder: a case report

We report a 44-year-old woman with calcific tendinitis of the shoulder treated with platelet-rich plasma injection. Prior to this, she had no improvement of the symptoms after 6 weeks of ultrasound treatment, Codman exercises, and anti-inflammatory treatment. Platelet-rich plasma was injected into the subacromial area 3 times at 2-week intervals. She had progressive improvement of pain after 2 weeks, and was asymptomatic at week 6. The patient then underwent the previous protocol of rehabilitation. At the one-year follow-up, the patient was pain-free and had complete resolution of calcific tendinitis. The patient had regained full range of movement and had resumed all her activities.

Platelet-rich plasma peptides: key for regeneration

Platelet-derived Growth Factors (GFs) are biologically active peptides that enhance tissue repair mechanisms such as angiogenesis, extracellular matrix remodeling, and cellular effects as stem cells recruitment, chemotaxis, cell proliferation, and differentiation. Platelet-rich plasma (PRP) is used in a variety of clinical applications, based on the premise that higher GF content should promote better healing. Platelet derivatives represent a promising therapeutic modality, offering opportunities for treatment of wounds, ulcers, soft-tissue injuries, and various other applications in cell therapy. PRP can be combined with cell-based therapies such as adipose-derived stem cells, regenerative cell therapy, and transfer factors therapy. This paper describes the biological background of the platelet-derived substances and their potential use in regenerative medicine.

Antibacterial effect of plasma rich in growth factors (PRGF®-Endoret®) against Staphylococcus aureus and Staphylococcus epidermidis strains

BACKGROUND

Formulations containing plasma rich in growth factors (PRGF) are opening new avenues in the field of regenerative medicine.

AIM

To evaluate the potential antimicrobial effects of a product (plasma rich in growth factors; PRGF(®)-Endoret(®)) against both methicillin-sensitive and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. The potential effect of incorporating the patient's leucocytes into the PRGF formulation (F3+leu) was also studied.

METHODS

Blood samples were obtained from five healthy volunteers and used to prepare each type of PRGF (F1, F3 and F3+leu). Various biological assays were performed to compare the characteristics of the different formulations, including measurement of the concentration of platelets and leucocytes, and assays of coagulation. The microbiological activity of PRGF-Endoret against both staphylococcal strains was performed by counting the number of the surviving bacterial colonies after incubation at 0, 4 and 8 h with the different formulations.

RESULTS

The three PRGF-Endoret formulations evaluated were enriched in platelets by 1.10, 2.57 and 1.89 times, respectively, and the leucocyte concentration in the F3+leu sample was increased by 3.9 times. We found that all formulations had a strong bacteriostatic effect, especially in the first 4 h after application. All formulations had an antibacterial effect at 4 h for three of the four strains, with the exception of methicillin-sensitive S. epidermidis. No differences in the bacterial inhibitory effect were found between the formulations.

CONCLUSIONS

This is the first time different formulations of this product have been evaluated, and the results suggest that PRGF-Endoret could be used in the fight against postoperative and wound infections.

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.

Open reduction and internal fixation of clavicular nonunions with allograft bone substitute

Background:

Biologic augmentation with allograft has shown equivalent healing rates to autograft in several nonunion models. No literature exists clearly demonstrating this in the clavicle. The purpose of this study was to evaluate the healing and complication rates of clavicle nonunions treated solely with open reduction and internal fixation (ORIF) and allograft.

Materials and Methods:

Nineteen clavicle nonunions treated with ORIF and allograft were evaluated retrospectively to assess healing rates and complications based on clinical symptoms and radiographic findings.

Results:

For the 19 patients included and treated with ORIF and allograft, clinical follow-up averaged 15 months. Seven patients were smokers. Although complete radiographic healing was achieved in only 68% of patients, clinical success occurred in 16 (84%) patients who demonstrated full range of motion and strength without pain. The three patients who did not demonstrate full radiographic healing were completely pain free. Five patients experienced complications (26%). Two underwent hardware removal due to persistent irritation after union. Three had a persistent painful nonunion. Each of these three patients was a smoker (P=0.08). Two proceeded to union after revision fixation. The other had hardware failure, which was removed, with a persistent nonunion and did not wish any further treatment.

Conclusion:

ORIF with allograft bone substitute is an acceptable treatment alternative to iliac crest bone graft for clavicle nonunions. However, we did not demonstrate equivalent healing rates to published results utilizing autograft. Smokers were identified to have a trend toward higher failure rates with ORIF augmented with allograft and therefore these patients may be better served by augmenting fixation with autograft.

Level of Evidence:

IV; retrospective comparative study.

Comparison of growth factor and platelet concentration from commercial platelet-rich plasma separation systems

BACKGROUND

Clinical studies claim that platelet-rich plasma (PRP) shortens recovery times because of its high concentration of growth factors that may enhance the tissue repair process. Most of these studies obtained PRP using different separation systems, and few analyzed the content of the PRP used as treatment.

PURPOSE

This study characterized the composition of single-donor PRP produced by 3 commercially available PRP separation systems.

STUDY DESIGN

Controlled laboratory study.

METHODS

Five healthy humans donated 100 mL of blood, which was processed to produce PRP using 3 PRP concentration systems (MTF Cascade, Arteriocyte Magellan, Biomet GPS III). Platelet, white blood cell (WBC), red blood cell, and fibrinogen concentrations were analyzed by automated systems in a clinical laboratory, whereas ELISA determined the concentrations of platelet-derived growth factor αβ and ββ (PDGF-αβ, PDGF-ββ), transforming growth factor β1 (TGF-β1), and vascular endothelial growth factor (VEGF).

RESULTS

There was no significant difference in mean PRP platelet, red blood cell, active TGF-β1, or fibrinogen concentrations among PRP separation systems. There was a significant difference in platelet capture efficiency. The highest platelet capture efficiency was obtained with Cascade, which was comparable with Magellan but significantly higher than GPS III. There was a significant difference among all systems in the concentrations of WBC, PDGF-αβ, PDGF-ββ, and VEGF. The Cascade system concentrated leukocyte-poor PRP, compared with leukocyte-rich PRP from the GPS III and Magellan systems.

CONCLUSION

The GPS III and Magellan concentrate leukocyte-rich PRP, which results in increased concentrations of WBCs, PDGF-αβ, PDGF-ββ, and VEGF as compared with the leukocyte-poor PRP from Cascade. Overall, there was no significant difference among systems in the platelet concentration, red blood cell, active TGF-β1, or fibrinogen levels.

CLINICAL RELEVANCE

Products from commercially available PRP separation systems produce differing concentrations of growth factors and WBCs. Further research is necessary to determine the clinical relevance of these findings.

Autologous Growth Factors: A Biological Treatment in Sports Medicine

Autologous growth factors have been used in maxillofacial and plastic surgery since the 1990s. The use of preparations rich in growth factors has seen an increase in sports medicine is due to its potential to enhance muscle, tendon, ligament and cartilage healing, and thereby accelerating an athlete's functional return to play. The efficacy of these autologous preparations rich in growth factors has seen varying healing effects for ligament, tendon, muscle, and cartilage injuries. Current clinical evidence is in its infancy with mainly animal and retrospective human studies, but the use of preparations rich in growth factors has increased, given its favourable safety profile and efficient preparation and delivery systems. It is important for physicians to keep abreast with the latest available preparation devices and current clinical evidence looking into the effects of autologous growth factors on tendon, ligament, muscle and cartilage healing.

A review on endogenous regenerative technology in periodontal regenerative medicine

Periodontitis is a globally prevalent inflammatory disease that causes the destruction of the tooth-supporting apparatus and potentially leads to tooth loss. Currently, the methods to reconstitute lost periodontal structures (i.e. alveolar bone, periodontal ligament, and root cementum) have relied on conventional mechanical, anti-infective modalities followed by a range of regenerative procedures such as guided tissue regeneration, the use of bone replacement grafts and exogenous growth factors (GFs), and recently developed tissue engineering technologies. However, all current or emerging paradigms have either been shown to have limited and variable outcomes or have yet to be developed for clinical use. To accelerate clinical translation, there is an ongoing need to develop therapeutics based on endogenous regenerative technology (ERT), which can stimulate latent self-repair mechanisms in patients and harness the host's innate capacity for regeneration. ERT in periodontics applies the patient's own regenerative 'tools', i.e. patient-derived GFs and fibrin scaffolds, sometimes in association with commercialized products (e.g. Emdogain and Bio-Oss), to create a material niche in an injured site where the progenitor/stem cells from neighboring tissues can be recruited for in situ periodontal regeneration. The choice of materials and the design of implantable devices influence therapeutic potential and the number and invasiveness of the associated clinical procedures. The interplay and optimization of each niche component involved in ERT are particularly important to comprehend how to make the desired cell response safe and effective for therapeutics. In this review, the emerging opportunities and challenges of ERT that avoid the ex vivo culture of autologous cells are addressed in the context of new approaches for engineering or regeneration of functional periodontal tissues by exploiting the use of platelet-rich products and its associated formulations as key endogenous resources for future clinical management of periodontal tissue defects.

The role of fibrin sealants in orthopaedic surgery

Blood conservation, specifically the avoidance of allogeneic blood transfusion, is becoming an important aspect of preoperative planning and intraoperative decision making in orthopaedic surgery. Knee and hip arthroplasty, as well as certain spine procedures, place patients at risk of significant blood loss. Fibrin sealants are topically applied hemostatic agents that reduce the time required to achieve hemostasis as well as the volume of blood loss. Fibrin sealants may provide additional benefits beyond hemostasis, such as improvements in wound healing and postoperative range of motion as well as lower rates of wound infections.

Platelet-rich plasma: from basic science to clinical applications

Platelet-rich plasma (PRP) has been utilized in surgery for 2 decades; there has been a recent interest in the use of PRP for the treatment of sports-related injuries. PRP contains growth factors and bioactive proteins that influence the healing of tendon, ligament, muscle, and bone. This article examines the basic science of PRP, and it describes the current clinical applications in sports medicine. This study reviews and evaluates the human studies that have been published in the orthopaedic surgery and sports medicine literature. The use of PRP in amateur and professional sports is reviewed, and the regulation of PRP by antidoping agencies is discussed.

Marrow stromal cell-based cyclooxygenase 2 ex vivo gene-transfer strategy surprisingly lacks bone-regeneration effects and suppresses the bone-regeneration action of bone morphogenetic protein 4 in a mouse critical-sized calvarial defect model

This study evaluated whether the murine leukemia virus (MLV)-based cyclooxygenase-2 (Cox-2) ex vivo gene-transfer strategy promotes healing of calvarial defects and/or synergistically enhances bone morphogenetic protein (BMP) 4-mediated bone regeneration. Gelatin scaffolds impregnated with mouse marrow stromal cells (MSCs) transduced with MLV-expressing BMP4, Cox-2, or a control gene were implanted into mouse calvarial defects. Bone regeneration was assessed by X-ray, dual-energy X-ray absorptiometry, and histology. In vitro, Cox-2 or prostanglandin E(2) enhanced synergistically the osteoblastic differentiation action of BMP4 in mouse MSCs. In vivo, implantation of BMP4-expressing MSCs yielded massive bone regeneration in calvarial defects after 2 weeks, but the Cox-2 strategy surprisingly did not promote bone regeneration even after 4 weeks. Staining for alkaline phosphatase (ALP)-expressing osteoblasts was strong throughout the defect of animals receiving BMP2/4-expressing cells, but defects receiving Cox-2-expressing cells displayed weak ALP staining along the edge of original intact bone, indicating that the Cox-2 strategy lacked bone-regeneration effects. The Cox-2 strategy not only lacked bone-regeneration effects but also suppressed the BMP4-induced bone regeneration. In vitro coculture of Cox-2-expressing MSCs with BMP4-expressing MSCs in gelatin scaffolds reduced BMP4 mRNA transcript levels, suggesting that Cox-2 may promote BMP4 gene silencing in BMP4-expressing cells, which may play a role in the suppressive action of Cox-2 on BMP4-mediated bone formation. In summary, the Cox-2 ex vivo gene-transfer strategy not only lacks bone-regeneration effects but also suppresses the bone-regeneration action of BMP4 in healing of calvarial defects.