PRP and articular cartilage: a clinical update

Semi-Bone Tunnel Technique Using Double-Row Suture Bridge Combined With Platelet-Rich Plasma Hydrogel for Rotator Cuff Repair in a Rabbit Model

BACKGROUND

The approach to managing the footprint area and reconstructing the tendon-bone interface (TBI) is critical for optimal healing.

PURPOSE

To evaluate the outcomes of the semi-bone tunnel (SBT) technique using a double-row suture bridge combined with platelet-rich plasma (PRP) hydrogel for rotator cuff repair in a rabbit model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 48 New Zealand White rabbits were divided into 4 groups. The supraspinatus tendons were severed at the footprint to create a rotator cuff tear model in the surgical groups. Rabbits were treated with the traditional onto-surface repair (control group), SBT technique (SBT group), and SBT technique combined with PRP hydrogel implantation (SBT+PRP group). The rabbits without surgery were the normal group. At 8 weeks after surgery, macroscopic observation, magnetic resonance imaging (MRI) and micro-computed tomography (μCT) examinations, histological evaluations, and biomechanical tests were performed to assess the curative effects of the given treatments.

RESULTS

The MRI results showed that the repaired supraspinatus tendon presented a uniform signal, minimal inflammatory response, and the lowest signal-to-noise quotient value in the SBT+PRP group. The μCT results suggested that the SBT technique did not reduce the local bone mineral density in the TBI area compared with the onto-surface repair technique. The histological staining results showed that the regenerated TBI in the SBT+PRP group had a 4-layer structure similar to the natural tissue. The highest values for biomechanical properties were observed in the SBT+PRP group, and there was no significant difference between the SBT+PRP group and normal group.

CONCLUSION

The SBT technique presented a better tendon-bone healing effect for rotator cuff tear in the rabbit model compared with the traditional onto-surface repair technique. The specimens in the SBT+PRP group had a similar TBI structure and biomechanical properties to the natural tissue.

CLINICAL RELEVANCE

The SBT technique can be an alternative surgical approach for rotator cuff repair, especially for moderate to large tears and cases requiring scaffold implantation.

Treatment of knee cartilage lesions in 2024: From hyaluronic acid to regenerative medicine

Abstract

Intact articular cartilage plays a vital role in joint homeostasis. Local cartilage repairs, where defects in the cartilage matrix are filled in and sealed to congruity, are therefore important treatments to restore a joint equilibrium. The base for all cartilage repairs is the cells; either chondrocytes or chondrogeneic cells from bone, synovia and fat tissue. The surgical options include bone marrow stimulation techniques alone or augmented with scaffolds, chondrogeneic cell implantations and osteochondral auto- or allografts. The current trend is to choose one-stage procedures being easier to use from a regulatory point of view. This narrative review provides an overview of the current nonoperative and surgical options available for the repair of various cartilage lesions.

Level of Evidence

Level IV.

Applying additional autologous platelet-rich fibrin matrix or serial platelet-rich plasma to microfracture technique increases the quality of the repaired cartilage

PURPOSE

The aim of the present study is to investigate and compare the effects of biological adjuvants (platelet-rich plasma, platelet-rich fibrin matrix) and microfracture technique individually and in combination on full thickness chondral defects in a rabbit model.

METHODS

A total of 60 New Zealand White rabbits were randomly divided into six groups according to treatment modality as follows: control (C), microfracture (MF), platelet-rich plasma (PRP), platelet-rich fibrin matrix (PRFM), platelet-rich fibrin matrix after microfracture (MF + PRFM) and platelet-rich plasma after microfracture (MF + PRP) groups. The cartilage repair tissue was assessed histologically via International Cartilage Repair Score (ICRS) and macroscopically via ICRS macroscopic assessment scale.

RESULTS

It was shown that overall macroscopic scores of the groups with MF were higher than those of the groups without MF. The cell morphology observed in the defect areas was mostly characterized with non-chondrocyte cells in the groups without MF, whereas chondrocyte cells mostly prevailed in the groups with MF. There was a greater integration through the cartilage-like tissue in the MF + PRP and MF + PRFM groups. The control group showed either fissures or fissures partially filled with fibrous tissue. When the groups were individually examined, there were statistically significant differences between the control and MF groups (p = 0.002), between the control and MF + PRFM groups (p = 0.001), between the control and MF + PRP groups (p < 0.001), between the PRFM and MF + PRFM groups (p = 0.014) and between the PRFM and MF + PRP (p = 0.023) groups in terms of histological evaluation scores.

CONCLUSION

The application of PRP and PRFM in combination with MF treatment exhibited a positive impact on the repair and restoration of cartilage, and produced better outcomes than the individual use of PRP and PRFM. Nevertheless, in the treatment of full thickness chondral defects, the use of PRFM injection is recommended, which is performed intraoperatively at a single time and with no difficulty of repeating after surgery, instead of serial PRP injections based on the macroscopic and histological results obtained in the present study indicating that there was no significant difference between the use of these two adjuvants.

The Efficacy of Platelet-Rich Plasma Augmentation in Microfracture Surgery Osteochondral Lesions of the Talus: A Systematic Review and Meta-Analysis

The appropriate surgical management of osteochondral lesions of the talus (OLT) remains a challenge for foot and ankle surgeons. Currently, microfracture (MF) is the first-line operative treatment for small osteochondral lesions. However, the fibrous cartilage regenerated after MF is mechanically inferior to hyaline cartilage regeneration and is susceptible to deterioration over time. Thus, this meta-analysis aimed to elucidate the efficacy of platelet-rich plasma (PRP) augmentation compared with MF only or other adjuvant supplementations combined with the PRP + MF group (others) for the management of OLT. We searched the PubMed, Embase, Web of Science, and Cochrane Library databases for studies that compared the clinical outcomes of patients who underwent MF only and those who underwent PRP or other adjuvant materials such as hyaluronic acid or BST-CarGel. After the screening, four randomized controlled trials and one quasi-randomized controlled trial were included in this review. We used the following tools for clinical evaluation: the American Orthopedic Foot and Ankle Society (AOFAS) score, Ankle-Hindfoot Scale score, Visual Analog Scale (VAS) score for pain, and the Foot and Ankle Ability Measure (FAAM) score. The standardized mean difference (SMD) was used to analyze the differences in outcomes between groups. Patients in the PRP + MF group had superior final VAS and AOFAS scores to the MF only group. (both p < 0.01) However, no significant improvements between baseline and final follow-up were noted in either score. In addition, there was no remarkable difference in the overall FAAM pain measures between the two groups. The PRP + MF and others groups revealed no significant effect differences in the clinical scores. The results of this analysis suggest that PRP + MF would be more favorable and effective than MF only or additional adjuvant supplementation.

Efficacy analysis of splint combined with platelet-rich plasma in the treatment of temporomandibular joint osteoarthritis

Objective: To evaluate the efficacy of splints combined with PRP for the treatment of temporomandibular joint osteoarthritis. Methods: Thirty-one patients with temporomandibular joint osteoarthritis who were treated with splints combined with platelet-rich plasma (PRP) from January 2021 to June 2021 at the Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University (Shenyang, China) were retrospectively reviewed. The VAS scores of all the patients were recorded before and 6 months after treatment, and the maximum comfortable mouth opening was recorded. All data were analyzed by the paired t-test using SPSS software, and a p-value < 0.05 indicated statistically significant differences. Results: Splint + PRP treatment was successful in 31 patients. The mean pretreatment VAS score was 6.1, and the mean VAS score 6 months posttreatment was 4.1. The posttreatment VAS score was significantly lower than the preoperative VAS score (p < 0.05). The mean pretreatment maximum comfortable mouth opening (MCMO) was 27.6 mm, and the mean MCMO 6 months posttreatment was 34.8 mm. The MCMO was significantly increased (p < 0.05). Conclusion: Splint + PRP is an effective treatment for temporomandibular joint osteoarthritis.

Regenerative Injection Treatments Utilizing Platelet Products and Prolotherapy for Cervical Spine Pain: A Functional Spinal Unit Approach

Background

The increasing burden of musculoskeletal disorders combined with the high utilization of opiates and the relatively limited ability of traditional approaches to satisfactorily address many of these conditions has spurred an increased interest in alternative treatments such as regenerative medicine therapies. Evidence is growing to support the use of regenerative injection treatments, including prolotherapy, platelet-rich plasma (PRP), platelet lysate (PL), and mesenchymal stromal cells. This study aims to offer a proof of concept via a case series of patients with neck pain treated using a functional spinal unit (FSU) model with combination prolotherapy, PRP, and PL injections.

Methodology

A chart review identified patients with neck pain treated with a combination of cervical injections using concentrated platelets and prolotherapy.

Results

A total of 14 patients met the inclusion criteria. The average decrease in the Numeric Pain Score was 2.8 (p = 0.002). The mean decrease in the Functional Rating Index was 27.3 (p = 0.004) at 24 months. Two patients had mild adverse reactions.

Conclusions

This case series demonstrates basic safety and clinically significant improvements in patients treated for neck pain with autologous concentrated platelet products and prolotherapy utilizing an FSU treatment protocol. Additional clinical studies are warranted with a larger patient sample size and longer follow-up periods.

Evaluation of the influence of platelet-rich plasma (PRP), platelet lysate (PL) and mechanical loading on chondrogenesis in vitro

The aim of this work is to investigate the capability of PRP as an adjuvant therapy to autologous chondrocyte implantation (ACI) in combination with multi-axial load with respect to cartilage regeneration. Articular cartilage shows poor repair capacity and therapies for cartilage defects are still lacking. Well-established operative treatments include ACI, and growing evidence shows the beneficial effects of PRP. Platelets contain numerous growth factors, among them transforming growth factor beta (TGF-β). Dynamic mechanical loading is known to be essential for tissue formation, improving extracellular matrix (ECM) production. For our ACI model monolayer expanded human chondrocytes were seeded into polyurethane scaffolds and embedded in fibrin (hChondro), in PRP-Gel (PRP), or in fibrin with platelet lysate (PL), which was added to the media once a week with a concentration of 50 vol%. The groups were either exposed to static conditions or multi-axial forces in a ball-joint bioreactor for 1 h per day over 2 weeks, mimicking ACI under physiological load. The culture medium was collected and analyzed for glycosaminoglycan (GAG), nitrite and transforming growth factor beta 1 (TGF-β1) content. The cell-scaffold constructs were collected for DNA and GAG quantification; the expression of chondrogenic genes, TGF-β and related receptors, as well as inflammatory genes, were analyzed using qPCR. Loading conditions showed superior chondrogenic differentiation (upregulation of COL2A1, ACAN, COMP and PRG4 expression) than static conditions. PRP and PL groups combined with mechanical loading showed upregulation of COL2A1, ACAN and COMP. The highest amount of total TGF-β1 was quantified in the PL group. Latent TGF-β1 was activated in all loaded groups, while the highest amount was found in the PL group. Load increased TGFBR1/TGFBR2 mRNA ratio, with further increases in response to supplements. In general, loading increased nitrite release into the media. However, over time, the media nitrite content was lower in the PL group compared to the control group. Based on these experiments, we conclude that chondrogenic differentiation is strongest when simulated ACI is performed in combination with dynamic mechanical loading and PRP-gel or PL supplementation. An inflammatory reaction was reduced by PRP and PL, which could be one of the major therapeutic effects. Loading presumably can enhance the action of TGF-β1, which was predominantly activated in loaded PL groups. The combination of load and PRP represents an effective and promising synergy concerning chondrocyte-based cartilage repair.

Stem Cells in Autologous Microfragmented Adipose Tissue: Current Perspectives in Osteoarthritis Disease

Osteoarthritis (OA) is a chronic debilitating disorder causing pain and gradual degeneration of weight-bearing joints with detrimental effects on cartilage volume as well as cartilage damage, generating inflammation in the joint structure. The etiology of OA is multifactorial. Currently, therapies are mainly addressing the physical and occupational aspects of osteoarthritis using pharmacologic pain treatment and/or surgery to manage the symptomatology of the disease with no specific regard to disease progression or prevention. Herein, we highlight alternative therapeutics for OA specifically considering innovative and encouraging translational methods with the use of adipose mesenchymal stem cells.

Chondrocyte Aging: The Molecular Determinants and Therapeutic Opportunities

Osteoarthritis (OA) is a joint degenerative disease that is an exceedingly common problem associated with aging. Aging is the principal risk factor for OA, but damage-related physiopathology of articular chondrocytes probably drives the mechanisms of joint degeneration by a progressive decline in the homeostatic and regenerative capacity of cells. Cellular aging is the manifestation of a complex interplay of cellular and molecular pathways underpinned by transcriptional, translational, and epigenetic mechanisms and niche factors, and unraveling this complexity will improve our understanding of underlying molecular changes that affect the ability of the articular cartilage to maintain or regenerate itself. This insight is imperative for developing new cell and drug therapies for OA disease that will target the specific causes of age-related functional decline. This review explores the key age-related changes within articular chondrocytes and discusses the molecular mechanisms that are commonly perturbed as cartilage ages and degenerates. Current efforts and emerging potential therapies in treating OA that are being employed to halt or decelerate the aging processes are also discussed.

Cultured Horse Articular Chondrocytes in 3D-Printed Chitosan Scaffold With Hyaluronic Acid and Platelet Lysate

Three-dimensional (3D) printing has gained popularity in tissue engineering and in the field of cartilage regeneration. This is due to its potential to generate scaffolds with spatial variation of cell distribution or mechanical properties, built with a variety of materials that can mimic complex tissue architecture. In the present study, horse articular chondrocytes were cultured for 2 and 4 weeks in 3D-printed chitosan (CH)-based scaffolds prepared with or without hyaluronic acid and in the presence of fetal bovine serum (FBS) or platelet lysate (PL). These 3D culture systems were analyzed in terms of their capability to maintain chondrocyte differentiation in vitro. This was achieved by evaluating cell morphology, immunohistochemistry (IHC), gene expression of relevant cartilage markers (collagen type II, aggrecan, and Sox9), and specific markers of dedifferentiated phenotype (collagen type I, Runx2). The morphological, histochemical, immunohistochemical, and molecular results demonstrated that the 3D CH scaffold is sufficiently porous to be colonized by primary chondrocytes. Thereby, it provides an optimal environment for the colonization and synthetic activity of chondrocytes during a long culture period where a higher rate of dedifferentiation can be generally observed. Enrichment with hyaluronic acid provides an optimal microenvironment for a more stable maintenance of the chondrocyte phenotype. The use of 3D CH scaffolds causes a further increase in the gene expression of most relevant ECM components when PL is added as a substitute for FBS in the medium. This indicates that the latter system enables a better maintenance of the chondrocyte phenotype, thereby highlighting a fair balance between proliferation and differentiation.

Osteochondral Tissue Engineering: The Potential of Electrospinning and Additive Manufacturing

The socioeconomic impact of osteochondral (OC) damage has been increasing steadily over time in the global population, and the promise of tissue engineering in generating biomimetic tissues replicating the physiological OC environment and architecture has been falling short of its projected potential. The most recent advances in OC tissue engineering are summarised in this work, with a focus on electrospun and 3D printed biomaterials combined with stem cells and biochemical stimuli, to identify what is causing this pitfall between the bench and the patients' bedside. Even though significant progress has been achieved in electrospinning, 3D-(bio)printing, and induced pluripotent stem cell (iPSC) technologies, it is still challenging to artificially emulate the OC interface and achieve complete regeneration of bone and cartilage tissues. Their intricate architecture and the need for tight spatiotemporal control of cellular and biochemical cues hinder the attainment of long-term functional integration of tissue-engineered constructs. Moreover, this complexity and the high variability in experimental conditions used in different studies undermine the scalability and reproducibility of prospective regenerative medicine solutions. It is clear that further development of standardised, integrative, and economically viable methods regarding scaffold production, cell selection, and additional biochemical and biomechanical stimulation is likely to be the key to accelerate the clinical translation and fill the gap in OC treatment.

The effectiveness of platelet-rich plasma gel on full-thickness cartilage defect repair in a rabbit model

AIMS

The present study investigates the effectiveness of platelet-rich plasma (PRP) gel without adjunct to induce cartilage regeneration in large osteochondral defects in a rabbit model.

METHODS

A bilateral osteochondral defect was created in the femoral trochlear groove of 14 New Zealand white rabbits. The right knees were filled with PRP gel and the contralateral knees remained untreated and served as control sides. Some animals were killed at week 3 and others at week 12 postoperatively. The joints were harvested and assessed by Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) MRI scoring system, and examined using the International Cartilage Repair Society (ICRS) macroscopic and ICRS histological scoring systems. Additionally, the collagen type II content was evaluated by the immunohistochemical staining.

RESULTS

After 12 weeks post-surgery, the defects of the PRP group were repaired by hyaline cartilage-like tissue. However, incomplete cartilage regeneration was observed in the PRP group for three weeks. The control groups showed fibrocartilaginous or fibrous tissue, respectively, at each timepoint.

CONCLUSION

Our study proved that the use of PRP gel without any adjuncts could successfully produce a good healing response and resurface the osteochondral defect with a better quality of cartilage in a rabbit model. Cite this article: Bone Joint Res 2021;10(3):192-202.

Leucocyte-poor-platelet-rich plasma intra-operative injection in chondral knee injuries improve patients outcomes. A prospective randomized trial

PURPOSE

Evaluate the effects of intra-operative leucocyte-poor-platelet-rich plasma (PRP) (type P3-Bβ with endogenous activation) injection in International Cartilage Repair Society (ICRS) grade III knee chondral injuries treated by chondroplasties, to increase and ameliorate the repair tissue.

METHODS

Patients were divided into two groups. Group A (control) consisted of 31 patients and Group B (PRP) 33 patients, totaling 64 patients analyzed. Patients also could had associated injuries (meniscal and/or ACL) being equally divided between both groups to avoid bias. PRP was injected at the end of surgery in group B. The patient outcomes were assessed using subjective International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Tegner activity forms, prior to the surgery and three, six, 12, and 24 months after surgery (medium-term follow up).

RESULTS

IKDC and KOOS scores showed increase at each evaluation time points after surgery in both groups, but the treated Group (B) showed a higher increase with statistically significant difference. The Tegner activity scores were higher for the treated group only at six and 12 months.

CONCLUSION

Based on the subjective IKDC, KOOS, and Tegner scores, those patients affected by ICRS grade III chondral injuries undergoing arthroscopic chondroplasty who were also treated with PRP showed better and faster outcomes than the control group. Independently from the associated injury (meniscal or ACL). This difference could be measured for up to two years.

Platelet lysate reduces the chondrocyte dedifferentiation during in vitro expansion: Implications for cartilage tissue engineering

In vitro studies have demonstrated that platelet lysate (PL) can serve as an alternative to platelet-rich plasma (PRP) to sustain chondrocyte proliferation and production of extracellular matrix components in chondrocytes. The present study aimed to evaluate the direct effects of PL on equine articular chondrocytes in vitro in order to provide a rationale for in vivo use of PL. An in vitro cell proliferation and de-differentiation model was used: primary articular chondrocytes isolated from horse articular cartilage were cultured at low density under adherent conditions to promote cell proliferation. Chondrocytes were cultured in serum-free medium, 10% foetal bovine serum (FBS) supplemented medium, or in the presence of alginate beads containing 5%, 10% and 20% PL. Cell proliferation and gene expression of relevant chondrocyte differentiation markers were investigated. The proliferative capacity of cultured chondrocytes, was sustained more effectively at certain concentrations of PL as compared to that with FBS. In addition, as opposed to FBS, PL, particularly at percentages of 5% and 10%, could maintain the gene expression pattern of relevant chondrocyte differentiation markers. In particular, 5% PL supplementation showed the best compromise between chondrocyte proliferation capacity and maintenance of differentiation. The results of the present study provide a rationale for using PL as an alternative to FBS for in vitro expansion of chondrocytes for matrix-assisted chondrocyte implantation, construction of 3D scaffolds for tissue engineering, and treatment of damaged articular cartilage.

Degenerative osteoarthritis a reversible chronic disease

Osteoarthritis (OA) is the most common chronic musculoskeletal disorder. It can affect any joint and is the most frequent single cause of disability in older adults.

OA is a progressive degenerative disease involving the entire joint structure in a vicious circle that includes the capsule-bursa tissue inflammation, synovial fluid modifications, cartilage breakdown and erosions, osteochondral inflammatory damage leading to bone erosion and distortion.

Research has identified the initial inflammatory-immunologic process that starts this vicious cycle leading to so-called early OA. Research has also identified the role played in the disease advancement by synoviocytes type A and B, chondrocytes, extracellular matrix, local immune-inflammatory mediators and proteases.

This article investigates the joint-resident MSCs that play an essential local homeostatic role and regulate cell turn over and tissue repair. Resident MSCs establish and maintain a local regenerative microenvironment.

The understanding of OA physiopathology clarifies the core mechanisms by which minimally invasive interventions might be able to halt and reverse the course of early stage OA. Interventions employing PRP, MSCs and exosomes are considered in this article.

Platelet rich plasma for treatment of osteochondral lesions of the talus: A systematic review of clinical trials

BACKGROUND

The ankle is the second most frequent site, following the knee, that requires cartilage repair. Osteochondral lesion of the talus (OLT) is common among athletes and is a result of talar cartilage detachment with or without subchondral bone fragmentation after a traumatic event. Treatment strategies for OLT can be classified as reparative or replacement interventions, with the former taking precedence. Recent studies show that the growth factors and bioactive components in platelet rich plasma (PRP) could improve cartilage regeneration. The prospect of using autologous blood to obtain a product that could enhance regeneration in damaged cartilage has been regarded as innovative, as it could circumvent the need for a replacement, and potentially join the ranks of first line reparative interventions against cartilage diseases.

METHODS

Literature searches were performed across seven search engines for randomized controlled trials using PRP to treat patients with OLT. Outcomes extracted included ankle function and pain measures. Level of evidence and methodological quality were evaluated using relevant guidelines.

RESULTS

Four studies met the eligibility criteria and were systematically appraised. Two studies scored Level 1 and 2 scored Level 2 based on the LOE assessment. MQOE evaluation revealed one study with excellent quality, and three with good quality. Overall results showed that PRP, as an adjunct to microfracture surgery, significantly improved function and reduced pain compared to microfracture surgery alone. Intra-articular PRP injection also demonstrated significantly enhanced recovery of function, and decreased pain scores compared to HA.

CONCLUSION

PRP improves joint function, and reduces pain in patients with OLT regardless of the method of implementation. In addition, inter-study comparison demonstrated that patients that received surgery along with PRP injections improved more than those that received PRP only. The studies that corroborate this conclusion have high levels of evidence with satisfactory methodological quality.

LEVEL OF EVIDENCE

Level 2, systematic review of Level 1 and 2 studies.

No effect of platelet-rich plasma as adjuvant to bone marrow stimulation for the treatment of chondral defects in a large animal model

BACKGROUND

Bone marrow stimulation (BMS) remains a dominant treatment strategy for symptomatic full thickness articular cartilage defects. Autologous platelet-rich plasma (PRP), may improve biological cartilage repair as an adjunct to BMS.

OBJECTIVES

To assess the histological quality of cartilage repair after BMS with and without repeated local injections of PRP for the treatment of full-thickness focal chondral defects of the knee.

METHODS

Two full-thickness chondral defects (Ø = 6 mm) were surgically performed in the medial and lateral trochlea of each knee in skeletally mature Göttingen minipigs. The two treatment groups with 12 defect for each groups were (1) BMS with one weekly PRP injection for 4 weeks, and (2) BMS alone. The animals were euthanized after 6 months. Samples of both whole blood and PRP were analysed with an automated hematology analyzer to determine the concentrations of platelets and nucleated cells. The composition of cartilage repair tissue was assessed using gross appearance assessment, histomorphometry and semi-quantitative scoring (ICRS II).

RESULTS

The average fold increase in platelets was 10.2 ± 2.2. Leukocyte concentration increased in PRP samples by an average fold change of 7.2 ± 1.3. Our macroscopic findings showed that the defects in the BMS + PRP-treated group, were filled with an irregular, partially rough tissue similar to the BMS-treated group. No significant difference in amount of hyalin cartilage, fibrocartilage or fibrous tissue content and ICRS II scores was found between the groups.

CONCLUSIONS

Four repeated local injections of leukocyte-rich PRP after BMS in the treatment of full-thickness cartilage injuries demonstrated no beneficial effects in terms of macroscopic and histological cartilage repair tissue quality.

Platelet-rich plasma combined with injectable hyaluronic acid hydrogel for porcine cartilage regeneration: a 6-month follow-up

Based on our previous study, the utilization of an ultraviolet light photo-cross-linkable hyaluronic acid (HA) hydrogel integrated with a small molecule kartogenin-encapsulated nanoparticles obtained good reconstruction of osteochondral defects in a rabbit model, indicating the superiority of injectable hydrogel-based scaffolds in cartilage tissue engineering. Platelet-rich plasma (PRP), rich in various growth factors, proteins and cytokines, is considered to facilitate cartilage healing by stimulating cell proliferation and inducing chondrogenesis in cartilage defect site. The aim of this study was to test the therapeutic feasibility of autologous PRP combined with injectable HA hydrogel on cartilage repair. The focal cartilage defects with different critical sizes in the medial femoral condyle of a porcine model were used. At 6 months, the minipigs were sacrificed for assessment of macroscopic appearance, magnetic resonance imaging, micro-computed tomography, histology staining and biomechanics. The HA hydrogel combined with PRP-treated group showed more hyaline-like cartilage exhibited by macroscopic appearance and histological staining in terms of extracellular matrix and type II collagen without formation of hypertrophic cartilage, indicating its capacity to improve cartilage healing in the minipig model evaluated at 6 months, with full-thickness cartilage defect of 8.5 mm diameter and osteochondral defect of 6.5 mm diameter, 5 mm depth exhibiting apparent regeneration.

Chondrocytes Proliferation of Patients with Cartilage Lesions in Their Own Body for Use in Cartilage Tissue Engineering: Hypotheses on a New Approach for the Proliferation of Autologous Chondrocytes

Osteoarthritis is one of the most common chronic diseases, which have involved 250 million people around the world. One of the challenges in the field of cartilage tissue engineering is to provide an adequate source of chondrocytes to prevent changes in gene expression profile as a result of multiple passages.We hypothesized that by creating a low invasive lesion by scalpel or shear laser in the outer ear cartilage and stimulation of wound healing process, hyperplasia occurs and will provide an appropriate number of autologous chondrocytes for extraction and use in articular cartilage tissue engineering. Also, due to the effect of platelet-rich plasma and biomechanical forces in stimulating and accelerating of the repair process, these two factors can be used to achieve more desirable results.We describe a new approach to proliferate chondrocytes in the body. To evaluate this idea, various techniques of gene expression at the level of RNA or protein and animal experiments for histological studies can be used. Also, flowcytometry technique can be used to determine the cell viability and counting them.The use of autologous cell sources with minimal changes in gene expression profile can be promising in tissue engineering products.

Understanding Articular Cartilage Injury and Potential Treatments

The goals of all orthopaedic surgeons treating articular cartilage injuries have been anatomic reduction and stable fixation of the articular cartilage surface with restoration of limb alignment and/or reestablishment of the joint stability, all while minimizing the risk of surgical complications. Recent developments in the study of articular cartilage injury have shown that there is a robust cellular response to joint injury. This response has been shown to involve the synoviocytes, chondrocytes, and osteocytes in and around the injured joint and if these responses are left unchecked, they can lead to the development of posttraumatic osteoarthritis (PTOA). Therefore, to predictably and successfully treat articular cartilage injuries, it is not sufficient to just restore articular congruity, limb alignment, and joint stability, but we must also recognize and attempt to mitigate this associated cellular response. Understanding not only the mechanical aspects of these joint injuries but also the biological aspects is paramount to giving our patients the best opportunity to heal their injuries, recover full function, and avoid the potential devastating development of PTOA. Gone is the simplistic view that if one can achieve articular congruity after intraarticular fracture, as well as joint stability after ligamentous injury, that our patients will do just fine. This review sheds new light on the molecular response to cartilage injury, how residual joint incongruity and instability affect the joint's ability to recover from injury, and how chondrocyte apoptosis in response to injury can influence joint. This article then briefly reviews how cellular and growth factors may be beneficial to the treatment of articular cartilage injury and how ultimately cartilage regeneration may be used in the future to salvage the joints ravaged by PTOA in response to injury.

Effectiveness of Platelet-Rich Plasma in the Management of Knee Osteoarthritis in a Rural Clinic

BACKGROUND

Osteoarthritis (OA) is a degenerative disease causing decreased mobility. Use of autologous platelet-rich plasma (PRP) provides a reparative alternative in the management of OA.

METHODS/PURPOSE

This study assessed effectiveness of nurse practitioner-injected PRP to manage knee OA in a rural setting.

RESULTS

Twenty patients were followed for 1 month after PRP treatment. Knee function and pain levels were assessed using a knee function score (Knee Injury and Osteoarthritis Outcome Score Physical Function Short Form [KOOS-PS]).

CONCLUSIONS

Overall, the 20 patients who participated in this study experienced significant improvement in knee function scores, decreased pain, and decreased use of pain medications.

Efficiency of platelet-rich plasma therapy in knee osteoarthritis does not depend on level of cartilage damage

OBJECTIVES

Osteoarthritis of the knee is common and often leads to significant physical disability. While classic conservative therapeutic approaches aim for symptoms like pain and inflammation, procedures like the intraarticular application of hyaluronic acids (HA) or platelet-rich plasma (PRP) are thought to stimulate the endogenous HA production, stop catabolism of cartilage tissue, and promote tissue regeneration. To analyse whether the positive effects of PRP injections are associated with the level of cartilage damage, patient satisfaction with the treatment was correlated with the level of knee joint osteoarthritis quantified by MRI.

METHODS

PRP was performed with a low-leukocyte autologous conditioned plasma (ACP) system in 59 patients. A pre-treatment MRI was performed and a Whole-Organ MRI Score (WORMS) was used to score the level of knee osteoarthritis by 14 features: integrity of the cartilage, affection of the bone marrow, subcortical cysts, bone attrition, osteophytes, integrity of the menisci and ligaments, presence of synovitis, loose bodies, and periarticular cysts. A multivariate analysis with ordinary least squares regressions was used.

RESULTS

Although pain symptoms and severity of clinical osteoarthritis symptoms decreased, regression analysis could not detect a correlation between the degree of cartilage damage measured by the WORMS score and a positive response to PRP therapy.

CONCLUSION

This study suggests that intraarticular injection of PRP might improve osteoarthritis symptoms and reduces the pain in patients suffering from osteoarthritis of the knee joint independent from the level of cartilage damages quantified by the whole-organ MRI scoring method WORMS.

Allogeneic platelet rich plasma serves as a scaffold for articular cartilage derived chondroprogenitors

Limited self-restorative ability of the cartilage has necessitated the use of cell and tissue engineering based therapies. Recent advances in the isolation, expansion and characterization of articular cartilage derived chondroprogenitors(CPs) has gained popularity in its role for cartilage repair. Platelet rich plasma (PRP) is a reliable biological scaffold for in-vitro and in-vivo studies with reported therapeutic applications in cartilage and bone pathologies. The aim of this study was to evaluate whether human allogeneic PRP could serve as a biological scaffold for chondroprogenitors (CPs) in cartilage repair. CPs were isolated from the superficial layer of three osteoarthritic knee joints by fibronectin adhesion assay and characterized using flow cytometric analysis. Allogeneic citrated blood was harvested from three subjects to obtain PRP. CPs at a concentration of one million cells per ml were gelled with PRP using calcium chloride. The PRP-CP scaffolds were subjected for adipogeneic, osteogenic, chondrogeneic differentiation and processed for post differentiation-staining studies (Oil Red O, Von Kossa, Alcian blue staining), immunofluorescence (collagen II) and live dead assays (Calcein AM-Ethidium Homodimer). We show that PRP was able to sustain CP cell viability and differentiate towards adipogenic, osteogenic and chondrogenic lineage under appropriate culture conditions. We also noted positive extracellular matrix production in PRP-CP scaffolds cultured without chondrogenic supplementation. Our results suggest that PRP could be a promising bio-active scaffold due to its synergistic effect in supporting cell proliferation, maintaining cell viability and favoring extracellular matrix production. PRP can be used as biological scaffold for the delivery of CPs in cartilage healing.

Platelet-Rich Plasma and the Knee-Applications in Orthopedic Surgery

PURPOSE OF REVIEW

To consolidate and synthesize the most recent evidence on the effects of platelet-rich plasma (PRP) in the knee with respect to osteoarthritis, meniscal injuries, ACL reconstruction, total knee arthroplasty (TKA), and high tibial osteotomy.

RECENT FINDINGS

PRP has been shown to be more beneficial in the context of knee osteoarthritis compared to both placebo and hyaluronic acid. Direct comparison with corticosteroid injections has been sparsely studied. It has also been shown to improve the clinical postoperative course in meniscal injuries and to a lesser extent TKA. Radiographic improvements without clinically significant benefits have been observed with ACL reconstructions treated with PRP. PRP injections may be more beneficial than other current non-surgical management options for specific knee pathologies. Further research should broaden the knowledge of PRP effects on the knee, and identify the type of PRP, growth factor distribution, and route of administration associated with the most benefit.

Optimization of the Platelet-Rich Plasma Concentration for Mesenchymal Stem Cell Applications

IMPACT STATEMENT

In the current study, we screened the effects of different concentrations of platelet-rich plasma (PRP) on the mesenchymal stem cell (MSC) proliferation and differentiation. Our data demonstrated that concentrated PRP exerted different effects on cell proliferation and on the osteogenic, adipogenic, and chondrogenic differentiation of human bone marrow-derived MSCs. Meanwhile, we optimized PRP concentrations for each of these lineage differentiation and MSC expansion and, thus, suggested several promising clinical strategies for different kinds of diseases. These findings may help explain the controversial effects of PRP on MSCs and improve the progress in precise applications of PRP-based regenerative strategies.

Protective effects of platelet-rich plasma against lidocaine cytotoxicity on canine articular chondrocytes

Background

Lidocaine (LD) is one of the most commonly used local anesthetics for performing arthroscopic surgery and managing of osteoarthritic pain in both human and veterinary medicine. However, over the last years, several studies have focused on the chondrotoxic effects of LD. In order to ensure that intra-articular lidocaine is safe to use, treatments aimed at mitigating chondrocyte death have recently been investigated. The aim of this study is to evaluate the possible protective effects of platelet-rich plasma (PRP) against LD cytotoxicity on canine articular chondrocytes.

Results

Articular canine chondrocytes, were exposed to 1% or 1.8% LD alone or in co-presence with 10% PRP for 30 min. In order to evaluate the effects of PRP pre-treatments, experiments were carried out on cells cultured in serum-free medium-or in medium supplemented with 10% PRP or 10% fetal bovine serum. Cell viability was evaluated by methyl thiazolyl tetrazolium assay and cell apoptosis was analyzed by flow cytometry using annexin V-fluorescein isothiocyanate/propidium iodide. The results showed that LD significantly reduced canine chondrocytes viability, probably due to apoptosis induction. Pre-treatment or the co-presence of PRP in the media restored the number of viable chondrocytes. The PRP also seemed to protect the cells from LD-induced apoptosis.

Conclusions

Pre-treatments and/or the simultaneous administration of PRP reduced LD-induced cytotoxicity in canine chondrocytes. Further in vivo studies are required to determine whether PRP can be used as a save protective treatment for dogs receiving intra-articular LD injections.

A double blind randomised control trial investigating the efficacy of platelet rich plasma versus placebo for the treatment of greater trochanteric pain syndrome (the HIPPO trial): a protocol for a randomised clinical trial

BACKGROUND

Greater trochanteric pain syndrome (GTPS) is a painful condition characterised by pain around the greater trochanter usually affecting middle-aged women. The majority of patients will improve with conservative management such as physiotherapy and non-steroidal anti-inflammatory drugs (NSAIDs); however, if this fails then more invasive treatments including corticosteroid injections and surgery may be required. Platelet-rich plasma (PRP) is an autologous blood product, which has a higher concentration of growth factors postulated to provide enhanced healing and anti-inflammatory properties. There have been numerous studies on PRP's efficacy in musculoskeletal soft tissue conditions with similar pathology to GTPS, with varying results, most promising being in plantar fasciopathy and patellar tendinopathy. Corticosteroids are the established second-line treatment, but do not always work long term. PRP may be a suitable alternative to corticosteroid in GTPS with longer-term effects; however, there are very limited reports. The Hip Injections PRP Vs Placebo (HIPPO) trial aims to assess the ability of PRP to improve symptoms and function in patients with GTPS.

METHODS/DESIGN

HIPPO is a single-centre, double-blind randomized placebo-controlled study in patients with a radiologically confirmed diagnosis of gluteus medius or minimus tendinopathy with swelling within the tendon insertion with or without bursitis. We aim to randomise 102 patients with GTPS to either the PRP or placebo (normal saline injection) treatment arm. Participants will receive one ultrasound (US) guided PRP/placebo injection into the trochanteric bursa and surrounding gluteus medius/minimus tendons. The primary outcome measure is the International Hip Outcome Tool-12. Secondary outcome measures will include a visual analogue score for pain, the three-level version of the EuroQol five-dimensional questionnaire and the modified Harris Hip Score. Outcomes will be measured at baseline, 3, 6 and 12 months. Participants will have the option at 6 months to have a repeat blinded injection or cross over to PRP. Analyses of primary and secondary outcomes will be made according to the intention-to-treat principle. The trial reporting will comply with Consolidated Standards of Reporting Trials (CONSORT) guidelines.

DISCUSSION

The HIPPO study has been designed to test the hypothesis that PRP is effective in treating GTPS in patients who have failed conservative management and to assess the duration of effect of PRP.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03479190 . Registered on 27 March 2018.

Platelet-Rich Plasma and Cartilage Repair

PURPOSE OF REVIEW

To assess the utilization and efficacy of platelet-rich plasma (PRP), for the treatment of articular cartilage injury, most commonly characterized by progressive pain and loss of joint function in the setting of osteoarthritis (OA).

RECENT FINDINGS

PRP modulates the inflammatory and catabolic environment through a locally applied concentrate of platelets, leukocytes, and growth factors. Clinically, PRP has been shown to be possibly a viable treatment adjuvant for a variety of inflammatory and degenerative conditions. Recent efforts have focused on optimizing delivery methods that enable platelets to slowly degranulate their biological constituents, which may promote healing and improve OA symptoms for a longer duration. There are various factors that affect the progression of OA within joints, including inhibition of inflammatory cytokines and altering the level of enzymatic expression. PRP therapy aims to mediate inflammatory and catabolic factors in a degenerative environment through the secretion of anti-inflammatory factors and chemotaxic effects. There are a growing number of studies that have demonstrated the clinical benefit of PRP for non-operative management of OA. Additional randomized controlled trials with long-term follow-up are needed in order to validate PRP's therapeutic efficacy in this setting. Additionally, continued basic research along with well-designed pre-clinical studies and reporting standards are necessary in order to clarify the effectiveness of PRP for cartilage repair and regeneration for future clinical applications.

Therapeutic Effects of the Addition of Platelet-Rich Plasma to Bioimplants and Early Rehabilitation Exercise on Articular Cartilage Repair

BACKGROUND

Treating articular cartilage lesions is clinically challenging. However, whether the addition of autologous platelet-rich plasma (PRP) to bioimplants along with early rehabilitation exercise provides therapeutic effects and regenerates the osteochondral defect remains uninvestigated.

HYPOTHESIS

The addition of PRP to a polylactic-co-glycolic acid (PLGA) scaffold along with continuous passive motion (CPM) in osteochondral defects may offer beneficial in situ microenvironment changes to facilitate hyaline cartilage and subchondral bone tissue repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

In 26 rabbits, 52 critical osteochondral defects were created in bilateral femoral trochlear grooves. The rabbits were allocated to 1 of the following 3 groups: PRP gel (PG group), PRP + PLGA scaffold (PP group), and PRP + PLGA scaffold + CPM (PPC group). At 4 and 12 weeks after surgery, the specimens were assessed by a macroscopic examination, a histological evaluation with immunohistochemical staining, and micro-computed tomography.

RESULTS

The PPC group exhibited the most favorable therapeutic outcomes in terms of hyaline cartilage regeneration. At week 4, the PPC group exhibited significantly higher levels of glycosaminoglycan (GAG) and collagen (COL) II and modest increases in COL I, matrix metalloproteinase-3 (MMP-3), and inflammatory cells with tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). At week 12, the PPC group had significantly higher tissue repair scores, corresponding to a sound articular cartilage surface and chondrocyte and collagen arrangement. This group demonstrated restored hyaline cartilage and mineralized bone volume per tissue volume, which had an integrating structure in the repair site. However, the PG and PP groups exhibited mainly fibrous tissue and fibrocartilage, corresponding to higher expressions of COL I, TNF-α, IL-6, and MMP-3.

CONCLUSION

PRP with a PLGA graft along with early CPM exercise is promising for the repair of osteochondral defects in rabbit knee joints.

CLINICAL RELEVANCE

This study demonstrates the efficacy of a triad therapy involving the addition of PRP to bioimplants along with early CPM intervention for hyaline cartilage and subchondral regeneration. However, PRP alone (with or without PLGA implants) is limited to osteochondral defect repair without significant regeneration.

Effects of platelet-rich plasma on the activity of human menstrual blood-derived stromal cells in vitro

Background

Human menstrual blood-derived stromal cells (MenSCs) are highly proliferative and show multiple differentiation capacity. The convenience and non-invasiveness make MenSC a novel cell source for regenerative medicine applications. Platelet-rich plasma (PRP) contains abundant growth factors which are beneficial to wound healing. However, the influence of PRP on MenSCs remains elusive. Here, we evaluated the role of PRP in MenSCs proliferation and assessed the effects of PRP on endometrial receptivity regulation in vitro.

Methods

MenSCs cultured with 10% activated PRP were compared with those cultured with 10% fetal bovine serum (FBS). Differences in cell proliferation, differentiation, and endometrial receptivity-related gene expression were evaluated.

Results

Notably, 10% activated PRP significantly promoted MenSCs proliferation and adipogenic/osteogenic differentiation while suppressing apoptosis. Expression of the mesenchymal stem cells (MSCs) marker CD105 and the perivascular markers SUSD2 and CD146 were elevated after PRP treatment. Moreover, short-term PRP stimulation activated the phosphorylation of Akt and signal transducer and activator of transcription 3 (STAT3) pathways, upregulated expression of FoxO1, LIF, and IL1-β, and downregulated IL-6.

Conclusions

In summary, PRP could promote MenSC proliferation, markedly accelerate cell stemness, and evaluate MenSC functions by enhancing the expression of angiogenesis and endometrial receptivity markers, suggesting its potential use as a promising supplement for MenSCs in endometrial regenerative medicine. Our results provide a theoretical basis for the clinical application of co-transplantation of PRP combined with MenSCs.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0795-3) contains supplementary material, which is available to authorized users.

A Call for Standardization in Platelet-Rich Plasma Preparation Protocols and Composition Reporting: A Systematic Review of the Clinical Orthopaedic Literature

BACKGROUND

Platelet-rich plasma (PRP) is a blood-derived preparation whose use has grown exponentially in orthopaedic practice. However, there remains an unclear understanding of the biological properties and effects of PRP on musculoskeletal healing. Heterogeneous processing methods, unstandardized nomenclature, and ambiguous classifications make comparison among studies challenging. A comprehensive assessment of orthopaedic clinical PRP trials is key to unraveling the biological complexity of PRP, while improving standardized communication. Toward this goal, we performed a systematic review of the PRP preparation protocols and PRP composition utilized in clinical trials for the treatment of musculoskeletal diseases.

METHODS

A systematic review of the literature was performed from 2006 to 2016. Inclusion criteria were human clinical trials, English-language literature, and manuscripts that reported on the use of PRP in musculoskeletal/orthopaedic conditions. Basic-science articles, editorials, surveys, special topics, letters to the editor, personal correspondence, and nonorthopaedic applications (including cosmetic use or dental application studies) were excluded.

RESULTS

A total of 105 studies (in 104 articles) met the inclusion criteria for analysis. Of these studies, only 11 (10%) provided comprehensive reporting that included a clear description of the preparation protocol that could be used by subsequent investigators to repeat the method. Only 17 studies (16%) provided quantitative metrics on the composition of the final PRP product.

CONCLUSIONS

Reporting of PRP preparation protocols in clinical studies is highly inconsistent, and the majority of studies did not provide sufficient information to allow the protocol to be reproduced. Furthermore, the current reporting of PRP preparation and composition does not enable comparison of the PRP products being delivered to patients. A detailed, precise, and stepwise description of the PRP preparation protocol is required to allow comparison among studies and provide reproducibility.

Biologic injections for osteoarthritis and articular cartilage damage: can we modify disease?

OBJECTIVE

The purpose of the present investigation is to conduct a systematic review of the literature to review the clinical results of platelet rich plasma (PRP) and mesenchymal stem cell treatments (MSC) (biologics) for articular cartilage lesions and osteoarthritis of the knee.

METHODS

A search of the PubMed, EMBASE, and Cochrane databases was performed to identify studies involving biologic therapy for osteoarthritis or osteochondral defects. Only Level I-III clinical trials with at least 3-month follow-up were included. Outcome data was gathered on any patient-completed surveys, 2nd look arthroscopy, follow-up imaging, biopsy/histology results, and any adverse effects of treatment.

RESULTS

Thirty-three articles met our inclusion criteria. There was a total of 21 PRP studies in the study. All PRP studies showed clinical improvement with PRP therapies in outcomes surveys measuring patient satisfaction, pain, and function. Two studies reported no significant difference in improvement compared to hyaluronic acid (HA). Similarly, the 7/9 MSC studies showed improvement. One study found BM-MSC implantation was not significantly superior to matrix assisted chondrocyte implantation (MACI), while one reported peripheral blood stem cells (PBSC) did not significantly improve outcomes over HA. Of the three studies looking at a combination of MSC/PRP, two found MSC/PRP combination did not improve outcomes compared to MSC or PRP therapy alone. The one PRP study that had a 2nd look arthroscopy reported increases cartilage regeneration with PRP. All 8 MSC studies with follow-up MRI and all 7 MSC studies with 2nd look arthroscopy showed improvement in cartilage regeneration in terms of coverage, fill of the defect, and/or firmness of the new cartilage.

CONCLUSION

Current data suggests that, of the two treatments, MSC provides more significant disease modifying effect; however, further research needs to be done to compare these two treatments and determine if there is a synergetic effect when combined.

Enhancement of abdominal wall defect repair using allogenic platelet-rich plasma with commercial polyester/cotton fabric (Damour) in a canine model

Platelet-rich plasma (PRP) has an important role in musculoskeletal surgery; however, it has been underutilized for accelerating the healing of abdominal wall defects in veterinary practice. Therefore, the aim of this study was to evaluate the use of commercial polyester/cotton fabric (Damour) as a new composite mesh for the repair of experimentally induced abdominal wall defects in canine models, and to investigate the possible role of PRP for improving such repair and reducing allied complications. For this purpose, abdominal wall defects were created in 24 healthy mongrel dogs and then repaired with mesh alone (control group) or mesh and allogenic PRP (PRP group). Dogs were euthanized after 2 or 4 months for gross examination of implantation site, detection of adhesion score and hernia recurrence. Moreover, tissue samples were collected for histological and gene expression analyses for neovascularization, collagen formation and tissue incorporation. Hernia recurrence was not recorded in PRP-treated dogs that also displayed significantly more neovascularization and less severe adhesion to the underlings (1.08 ± 0.51) in comparison to control group (2.08 ± 0.99). Histological and molecular evaluation confirmed the gross findings that collagen deposition, new vessel formation, and overexpression of angiogenic and myofibroplastic genes (COL1α1, COL3α1, VEGF and TGFβ1) were observed more frequently in the PRP group, at both time points. In conclusion, we found that addition of allogenic PRP to Damour mesh enhanced neovessel formation, and increased tissue deposition and incorporation, with subsequent reduction of peritoneal adhesion and recurrence rate.

In Vitro and In Vivo Studies of Alar-Nasal Cartilage Using Autologous Micro-Grafts: The Use of the Rigenera® Protocol in the Treatment of an Osteochondral Lesion of the Nose

Cartilage defects represent a serious problem due to the poor regenerative properties of this tissue. Regarding the nose, nasal valve collapse is associated with nasal blockage and persistent airway obstruction associated with a significant drop in the quality of life for patients. In addition to surgical techniques, several cell-based tissue-engineering strategies are studied to improve cartilage support in the nasal wall, that is, to ameliorate wall insufficiency. Nevertheless, there are no congruent data available on the benefit for patients during the follow-up time. In this manuscript, we propose an innovative approach in the treatment of cartilage defects in the nose (nasal valve collapse) based on autologous micro-grafts obtained by mechanical disaggregation of a small portion of cartilage tissue (Rigenera® protocol). In particular, we first analyzed in vitro murine and human cartilage micro-grafts; secondly, we analyzed the clinical results of a patient with pinched nose deformity treated with autologous micro-grafts of chondrocytes obtained by Rigenera® protocol. The use of autologous micro-graft produced promising results in surgery treatment of cartilage injuries and could be safely and easily administrated to patients with cartilage tissue defects.

Decrease of serum biomarker of type II Collagen degradation (Coll2-1) by intra-articular injection of an autologous plasma-rich-platelet in patients with unilateral primary knee osteoarthritis

OBJECTIVE

This study aimed to evaluate the effect of one dose of intra-articular injection of (PRP) in the knee joint on a specific osteoarthritis (OA) serum biomarker of cartilage degeneration, Collagen 2-1 (Coll2-1), over a short period of 3 months. The aim extended to clarify the effect of PRP on the functional status of the osteoarthritic knee joint.

MATERIAL AND METHODS

Sixty patients with primary unilateral knee OA were enrolled in this study. They were subdivided according to Kellgren-Lawrence grading scale (KL) into (Group I): including patients with KL grade < 3 and (Group II): including patients with KL grade ≥3. Patients were asked to complete the Western Ontario and McMaster Universities Arthritis Index (WOMAC) Score. PRP was prepared and injected immediately into the affected knee. Serum Coll2-1 (S.Coll2-1) concentration was measured by enzyme-linked immunosorbent assay (ELISA) kit pre and 3 months after PRP injection.

RESULTS

Significant reduction in S.Coll2-1 concentration in primary knee OA patients; (p<0.001) and (p<0.05) in group I and group II respectively as well as significant improvements in WOMAC total and WOMAC sub-scores values were noted after single intra-articular PRP injection with maximal functional improvements were achieved after 3 months (p<0.001). Mild cases experienced favorable results with no remarkable adverse reactions were observed.

CONCLUSION

Reduction in specific OA biomarker S.Coll2-1 following intra-articular PRP injection emphasize that PRP could be a promising safe and tolerable effective therapeutic option which improves function from basal states in primary knee OA patients.

Bone Marrow Aspirate Concentrate Harvesting and Processing Technique

Bone marrow obtained by iliac crest aspiration is a common source for harvesting mesenchymal stem cells, other progenitor cells, and associated cytokine/growth factors. Recent studies have reported good to excellent outcomes with the use of bone marrow aspirate concentrate (BMAC) for pain relief in the treatment of focal chondral lesions and osteoarthritis of the knee. However, the harvesting and processing technique are crucial to achieve satisfactory results. Several studies have examined outcomes after BMAC injection, with encouraging results, but there is a lack of consensus in terms of the frequency of injection, the amount of BMAC that is injected, and the timing of BMAC injections. The purpose of this Technical Note was to describe a standardized bone marrow aspiration harvesting technique and processing method.

Platelet-rich plasma (PRP) for knee disorders

Platelet-rich plasma (PRP) is an autologous blood product with platelet concentrations above baseline values. The process involves the extraction of blood from the patient which is then centrifuged to obtain a concentrated suspension of platelets by plasmapheresis. It then undergoes a two-stage centrifugation process to separate the solid and liquid components of the anticoagulated blood. PRP owes its therapeutic use to the growth factors released by the platelets which are claimed to possess multiple regenerative properties.

In the knee, PRP has been used in patients with articular cartilage pathology, ligamentous and meniscal injuries.

There is a growing body of evidence to support its use in selected indications and this review looks at the most recent evidence. We also look at the current UK National Institute of Health & Clinical Excellence (NICE) guidelines with respect to osteoarthritis and the use of PRP in the knee.

Cite this article: EFORT Open Rev 2017;2:28–34. DOI: 10.1302/2058-5241.2.160004.

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.

Novel Surgical Technique for Bone Marrow Lesion — Case Report

Introduction: Bone marrow lesions (BMLs) are commonly described as magnetic resonance imaging (MRI) findings associated with stress injuries or trauma. The presence of BMLs closely correlates with pain and rapid joint deterioration. Case presentation: A 51-year-old healthy man presented to our clinic with severe knee pain due to BMLs. After 3 months of conservative treatment, arthroscopy and subchondroplasty (SCP) of the medial femoral condyle was performed. The IKDC (International Knee Documentation Committee) score improved from 39.9 to 66.7 at 6 months, and to 87.4 at 1 year after surgery. The KOOS (Knee Injury and Osteoarthritis Outcome) score improved from 38.5 to 77.7 at 6 months, and to 92.6 at 1 year after surgery. The Tegner Lysholm score improved from 23 to 80 at 6 months, and to 95 at 1 year after surgery. Conclusion: SCP may provide a viable approach to reduce pain associated with BML, with minimal risk of significant complications.

Combining a novel leucocyte-platelet-concentrated membrane and an injectable collagen scaffold in a single-step AMIC procedure to treat chondral lesions of the knee: a preliminary retrospective study

BACKGROUND

Different surgical approaches are currently available to treat knee chondral defects. Microfracture is the most commonly applied, but it often leads to a mechanically inferior fibrocartilaginous tissue. To overcome this shortcoming, the Autologous, Matrix-Induced Chondrogenesis (AMIC) technique has been proposed. To further enhance the outcome of AMIC, the addition of haemoderivatives containing growth factors that stimulate cartilage healing has emerged as a new treatment method. Recently, a novel leucocyte-platelet-concentrated membrane (CLP-MB), highly enriched in platelets, monocytes/macrophages, fibrinogen, CD34⁺ and CD34⁺VEGFR-2⁺CD133⁺ cells, has been developed. Additionally, an injectable collagen scaffold (Cartifill) has been proposed as a replacement of the AMIC standard collagen membrane.

AIMS

This preliminary study is aimed to evaluate the short-term safety and efficacy of the use of the CLP-MB membrane and injectable collagen scaffold when combined in single-step AMIC procedures for the treatment of knee chondral lesions.

METHODS

Medical records of patients who underwent an AMIC procedure with the CLP-MB membrane combined with Cartifill were reviewed retrospectively. Follow-up assessments were conducted at 6 and 12 months after surgery. Clinical function was assessed on the basis of the International Knee Documentation Committee (IKDC) score. Pain was evaluated using the visual analogue scale (VAS).

RESULTS

Twenty-five patients were identified as meeting the inclusion criteria. Mean IKDC and VAS scores significantly improved during the follow-up time. The postoperative course was uneventful.

CONCLUSIONS

AMIC combined with the CLP-MB membrane, and Cartifill seems to be a promising approach to treat knee chondral defects.

Cartilage defect repair in horses: Current strategies and recent developments in regenerative medicine of the equine joint with emphasis on the surgical approach

Chondral and osteochondral lesions due to injury or other pathology are highly prevalent conditions in horses (and humans) and commonly result in the development of osteoarthritis and progression of joint deterioration. Regenerative medicine of articular cartilage is an emerging clinical treatment option for patients with articular cartilage injury or disease. Functional articular cartilage restoration, however, remains a major challenge, but the field is progressing rapidly and there is an increasing body of supportive clinical and scientific evidence. This review gives an overview of the established and emerging surgical techniques employed for cartilage repair in horses. Through a growing insight in surgical cartilage repair possibilities, surgeons might be more stimulated to explore novel techniques in a clinical setting.

Concentrated Bone Marrow Aspirate for the Treatment of Chondral Injuries and Osteoarthritis of the Knee: A Systematic Review of Outcomes

Background:

Bone marrow aspirate concentrate (BMAC) has emerged as a novel treatment for pathology of the knee. Despite containing a limited number of stem cells, BMAC serves as a source of growth factors that are thought to play an important role as a result of their anabolic and anti-inflammatory effects. To our knowledge, there is no systematic review regarding the outcomes of bone marrow aspirate concentrate used for the treatment of chondral defects and osteoarthritis of the knee.

Purpose:

To perform a systematic review on the outcomes of bone marrow aspirate concentrate for the treatment of chondral defects and osteoarthritis of the knee.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review of the literature was performed using the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, and MEDLINE from 1980 to present. Inclusion criteria were as follows: use of BMAC for treatment of chondral defects and osteoarthritis of the knee, English language, and human studies. We excluded cadaveric studies, animal studies, basic science articles, editorial articles, surveys, and studies that did not include the knee. After applying inclusion and exclusion criteria, studies were evaluated for efficacy and safety of BMAC for treatment of articular cartilage knee pathologies.

Results:

Eleven studies were considered. Of these, 5 were prospective studies, 1 was a retrospective study, 2 were case series, and 3 were case reports. Three comparative studies (2 with level 2 evidence, 1 with level 3 evidence) were found in our search; none of them were randomized. Three studies investigated the clinical efficacy of BMAC in the treatment of osteoarthritis, and 8 studies evaluated the efficacy of BMAC on focal cartilage injuries. All 3 studies regarding osteoarthritis and all 8 studies regarding focal chondral defects reported good to excellent overall outcomes with the use of BMAC.

Conclusion:

Although a growing interest for biological alternatives of treating knee pathology has been observed in the past few years, there still remains a paucity of high-quality studies. The studies included in this systematic review reported varying degrees of beneficial results with the use of BMAC with and without an additional procedure for the treatment of chondral defects and early stages of osteoarthritis. Most articles present the use of BMAC as a safe procedure and report good results.

Effectiveness of platelet-rich plasma in the treatment of moderate knee osteoarthritis: a randomized prospective study

[Purpose] To assess the effects of different numbers of platelet-rich plasma (PRP) applications on pain and physical function in grade 3 knee osteoarthritis (OA). [Subjects and Methods] A total of 102 patients with grade 3 knee OA were randomly divided into three groups: Group 1 received a single injection of PRP, Group 2 received two injections of PRP two weeks apart, Group 3 received three injections of PRP at 2-weeks intervals. All patients were evaluated with a visual analog scale (VAS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC), and the Timed-Up and Go test (TUG) before the treatment and at 1, 3 and 6 months after the treatment. [Results] Ninety-eight patients (15 males, 83 females) completed the study. The mean ages of the patients were 53.5±6.6, 54.9±5.3, and 55.1±5.6 years in Group 1, Group 2, and Group 3, respectively. Statistically significant improvements were noted in all of the evaluated measures in all of the groups. The mean differences of Group 1-Group 2 and Group 1-Group 3 WOMAC total, WOMAC pain, WOMAC stiffness, and WOMAC function scores were statistically significant. [Conclusion] PRP is an effective treatment for functional status and pain in moderate knee osteoarthritis and a minimum of two injections is appropriate.