Optimizing the safety of intradiscal platelet-rich plasma: an in vitro study with Cutibacterium acnes

The Role of Platelet Rich Plasma in Vertebrogenic and Discogenic Pain: A Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

The present investigation evaluates clinical uses and roles of platelet rich plasma in the management of vetrebrogenic and discogenic mediated pain states.

RECENT FINDINGS

Back pain is a common and significant condition that affects millions of people around the world. The cause of back pain is often complex and multifactorial, with discogenic and vertebrogenic pain being two subtypes of back pain. Currently, there are numerous methods and modalities in which back pain is managed and treated such as physical therapy, electrical nerve stimulation, pharmacotherapies, and platelet-rich plasma. To conduct this systematic review, the authors used the keywords "platelet-rich plasma", "vertebrogenic pain", and "discogenic pain", on PubMed, EuroPMC, Who ICTRP, and clinicaltrials.gov to better elucidate the role of this treatment method for combating vertebrogenic and discogenic back pain. In recent decades, there has been a rise in popularity of the use of platelet-rich plasma for the treatment of numerous musculoskeletal conditions. Related to high concentration of platelets, growth factors, cytokines, and chemokines, platelet-rich plasma is effective in reducing pain related symptoms and in the treatment of back pain. Platelet-rich plasma use has evolved and gained popularity for pain related conditions, including vertebrogenic and discogenic back pain. Additional well-designed studies are warranted in the future to better determine best practice strategies to provide future clinicians with a solid foundation of evidence to make advancements with regenerative medical therapies such as platelet-rich plasma.

Profound Properties of Protein-Rich, Platelet-Rich Plasma Matrices as Novel, Multi-Purpose Biological Platforms in Tissue Repair, Regeneration, and Wound Healing

Autologous platelet-rich plasma (PRP) preparations are prepared at the point of care. Centrifugation cellular density separation sequesters a fresh unit of blood into three main fractions: a platelet-poor plasma (PPP) fraction, a stratum rich in platelets (platelet concentrate), and variable leukocyte bioformulation and erythrocyte fractions. The employment of autologous platelet concentrates facilitates the biological potential to accelerate and support numerous cellular activities that can lead to tissue repair, tissue regeneration, wound healing, and, ultimately, functional and structural repair. Normally, after PRP preparation, the PPP fraction is discarded. One of the less well-known but equally important features of PPP is that particular growth factors (GFs) are not abundantly present in PRP, as they reside outside of the platelet alpha granules. Precisely, insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) are mainly present in the PPP fraction. In addition to their roles as angiogenesis activators, these plasma-based GFs are also known to inhibit inflammation and fibrosis, and they promote keratinocyte migration and support tissue repair and wound healing. Additionally, PPP is known for the presence of exosomes and other macrovesicles, exerting cell-cell communication and cell signaling. Newly developed ultrafiltration technologies incorporate PPP processing methods by eliminating, in a fast and efficient manner, plasma water, cytokines, molecules, and plasma proteins with a molecular mass (weight) less than the pore size of the fibers. Consequently, a viable and viscous protein concentrate of functional total proteins, like fibrinogen, albumin, and alpha-2-macroglobulin is created. Consolidating a small volume of high platelet concentrate with a small volume of highly concentrated protein-rich PPP creates a protein-rich, platelet-rich plasma (PR-PRP) biological preparation. After the activation of proteins, mainly fibrinogen, the PR-PRP matrix retains and facilitates interactions between invading resident cells, like macrophages, fibroblast, and mesenchymal stem cells (MSCs), as well as the embedded concentrated PRP cells and molecules. The administered PR-PRP biologic will ultimately undergo fibrinolysis, leading to a sustained release of concentrated cells and molecules that have been retained in the PR-PRP matrix until the matrix is dissolved. We will discuss the unique biological and tissue reparative and regenerative properties of the PR-PRP matrix.

Intradiscal Therapies for Lumbar Degenerative Disk Disease

Discogenic low back pain is a common musculoskeletal complaint in patients presenting to orthopaedic surgeons. In addition to surgical options, there are several nonsurgical intradiscal treatments that have gained interest, ranging from biologic, nonbiologic, cell-based, and molecular therapies. However, there is limited evidence for many of these techniques, and some are still in the clinical trial stage. We describe a broad overview of these intradiscal therapies, the mechanism of action, and the evidence behind them.

Lumbar instability as an etiology of low back pain and its treatment by prolotherapy: A review

BACKGROUND

Low back pain is a significant spinal disorder that affects much of the population at some point during their lives.

OBJECTIVE

While proper diagnosis is key, diagnosing the underlying cause of low back pain may often be unclear.

METHOD

In this review article, we discuss lumbar instability as an etiology of low back pain and its treatment by prolotherapy.

RESULTS

Spinal ligaments may be an underlying culprit in the development of lumbar instability with resultant low back pain and associated disorders.

CONCLUSION

In these cases, adequate treatment consisting of non-biologic prolotherapy or cellular prolotherapy, including platelet rich plasma (PRP), can be beneficial in restoring spinal stability and resolving chronic low back pain.

Personalized multitarget biologic injection in the spine: prospective case series of multitarget platelet-rich plasma for low back pain

Aim: To evaluate the use of a multitarget platelet-rich plasma (PRP) injection approach for the treatment of chronic low back pain (LBP). Materials & Methods: Forty-six patients with more than 12 weeks of LBP who failed conservative treatments were injected with PRP into the facet joints, intervertebral discs, epidural space and/or paravertebral muscles. Visual analog pain scale and Roland-Morris Disability Questionnaire scores were measured at baseline and predefined intervals. Results: Mean visual analog pain scale was reduced from 8.48 to 5.17 and mean Roland-Morris Disability Questionnaire from 18.0 to 10.98 at 12 weeks (p < 0.001). These statistically significant improvements were sustained over 52 weeks. No adverse effects were observed. Conclusion: Our PRP approach demonstrated clinically favorable results and may be a promising treatment for chronic LBP.

Antibacterial Properties of Canine Platelet-Rich Plasma and Other Non-Transfusional Hemo-Components: An in vitro Study

This in vitro study was carried out to evaluate the potential antibacterial properties of canine non-transfusional hemo-components. Therapeutic formulations commonly used for regenerative medicine purposes (platelet-rich plasma, platelet gel, platelet lysate, fibrin glue), considering both leukocyte-rich and leukocyte-poor formulations, but also platelet-poor plasma and activating substances (thrombin, calcium gluconate), were tested to detect elements with potential antimicrobial properties. The antibacterial effect was tested on different bacterial strains (Staphylococcus aureus subspecies aureus, Staphylococcus cohnii subspecies cohnii, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae subspecies pneumoniae) isolated from canine wounds and classified as susceptible, multidrug-, extensively, and pandrug-resistant bacteria toward a known panel of human and veterinary antibiotics. The evaluation was carried out by agar gel diffusion method (Kirby-Bauer) and micro-inhibition in broth using microplates and spectrophotometer reading. The study findings confirmed the hypothesized antibacterial properties of canine non-transfusional hemo-components. A more effective bacteriostatic effect was found against Gram-negative bacteria, drug-resistant too. The presence of leukocytes or platelets does not appear to be essential for the antibacterial effect. Further studies should be conducted to evaluate the exact mechanism of action of the antimicrobial activity. However, non-transfusional hemo-components could be a useful natural aid in controlling bacterial infections in dogs.

Ultrasound-guided L5/S1 intradiscal needle placement using biplanar approach with the patient in the lateral decubitus position: A report of three cases

BACKGROUND

The use of ultrasound (US)-guided intradiscal injection has been described in the literature with the patient lying in the prone position; however, many patients are unable to lie in the prone position. Therefore, we describe an innovative technique of US-guided platelet-rich plasma (PRP) administration in the lumbar intervertebral disc (IVD) of 3 patients with chronic lower back pain who failed to improve with conservative management.

CASE SERIES

For all the 3 patients, magnetic resonance imaging showed annular tears of the L5/S1 IVD with broad-based central posterior protrusions. PRP injection was performed with the patients in the lateral decubitus position or modified recovery position. With the transducer initially placed in the short axis to the lumbar spine, the needle was inserted in-plane to the IVD, with the needle trajectory clearly visualized. Once the needle entered the annulus fibrosus, placement of the needle was confirmed by turning the transducer along the long axis of the spine to validate the location of the needle tip inside the IVD. Discus stimulation was performed with contrast administered to elicit each patient's usual pain, and spread of the contrast was confirmed under fluoroscopy. Upon confirmation of the intradiscal location, 3 ml of PRP was administered.

CONCLUSIONS

This report described a novel technique demonstrating that US-guided lumbar intradiscal needle placement for PRP administration in patients lying in the lateral decubitus position is feasible.

Risks of Intradiscal Orthobiologic Injections: A Review of the Literature and Case Series Presentation

BACKGROUND

Intervertebral disc disease (IDD) is responsible for a large portion of back pain with historically suboptimal treatments for long-term improvement. IDD pathogenesis is thought to arise at a cellular and biochemical level, making biologically based injections an area of clinical interest. Although human studies have shown promise, emerging data suggest there may be risks inherent to such injections that were previously unrecognized. The aim of this review is to summarize the known risks to date and provide mitigation steps to reduce potential complications in the future. In addition, we present a small case series of serious adverse events (SAEs) from our clinical practice.

METHODS

A literature review was performed to identify human intradiscal autologous biologic injection studies to date, including mesenchymal signaling cells (MSCs) and platelet-rich plasma (PRP) preparations, which were reviewed for complications. Cases of complication following intradiscal orthobiologic injection were identified from a single outpatient center and reviewed.

RESULTS

Publications of MSC-based intradiscal injection documented 136 total patients treated with two SAEs reported, one infection and one progressive disc herniation. Publications of PRP intradiscal injection included 194 patients with one SAE reported. We also review three cases of previously unpublished SAEs, including one case of confirmed infection with Cutibacterium acnes (C acnes) and two presumed cases of discitis without pathogen confirmation. Bone marrow concentrate was the injectate in all three cases.

CONCLUSIONS

Although biologic intradiscal injection shows promise for the treatment of discogenic back pain, there are inherent risks to be considered and mitigated. We currently recommend a leukocyte-rich PRP and a two-needle delivery technique coupled with intradiscal gentamicin to mitigate the risk of postinjection spondylodiscitis. Further research is needed using large registries to not only track clinical outcomes but also complication rates.

Platelet Rich Plasma in Orthopedic Surgical Medicine

There is a global interest in optimizing post-surgical tissue repair strategies, leading to better patient outcomes and fewer complications, most ideally with reduced overall cost. In this regard, in recent years, the interest in autologous biological treatments in orthopedic surgery and sports medicine has increased greatly, and the addition of platelet-rich plasma (PRP) to the surgical armamentarium is of particular note. Unfortunately, the number of PRP preparation devices has also grown immensely over the recent decades, raising meaningful concern for the considerable variation in the qualities of currently available PRP preparations. The lack of consensus on the standardization of PRP preparation and of agreement on condition specific PRP formulations is largely responsible for the sometimes contradictory outcomes in the literature. Furthermore, the full potential of PRP technology, the concept of individualized treatment protocols based on bioformulation options, and platelet dosing, angiogenesis, and antimicrobial and painkilling effects of PRP relevant to orthopedic surgery have rarely been addressed. In this review, we will discuss recent developments regarding PRP preparations and potential therapeutic effects. Additionally, we present a synopsis of several published data regarding PRP applications in orthopedic surgery for treating tendon injuries, inducing bone repair, strengthening spinal fusion outcomes, and supporting major joint replacements.