Platelet-rich plasma treatment for ligament and tendon injuries

Application of Platelet-Rich Plasma-Based Scaffolds in Soft and Hard Tissue Regeneration

Platelet-rich plasma (PRP) is a blood product with higher platelet concentrations than whole blood, offering controlled delivery of growth factors (GFs) for regenerative medicine. PRP plays pivotal roles in tissue restoration mechanisms, including angiogenesis, fibroblast proliferation, and extracellular matrix development, making it applicable across various regenerative medicine treatments. Despite promising results in different tissue injuries, challenges such as short half-life and rapid deactivation by proteases persist. To address these challenges, biomaterial-based delivery scaffolds, such as sponges or hydrogels, have been investigated. Current studies exhibit that PRP-loaded scaffolds fix these issues due to the sustained release of GFs. In this regard, given the widespread application of PRP in clinical studies, the use of PRP-loaded scaffolds has drawn significant consideration in tissue engineering (TE). Therefore, this review briefly introduces PRP as a rich origin of GFs, its classification, and preparation methods and discusses PRP applications in regenerative medicine. This study also emphasizes and reviews the latest research on the using scaffolds for PRP delivery in diverse fields of TE, including skin, bone, and cartilage repair.

In-vitro and in-vivo assessment of biocompatibility and efficacy of ostrich eggshell membrane combined with platelet-rich plasma in Achilles tendon regeneration

Tendon injuries present significant medical, social, and economic challenges globally. Despite advancements in tendon injury repair techniques, outcomes remain suboptimal due to inferior tissue quality and functionality. Tissue engineering offers a promising avenue for tendon regeneration, with biocompatible scaffolds playing a crucial role. Ostrich eggshell membrane (ESM), characterized by a strong preferential orientation of calcite crystals, forms a semipermeable polymer network with excellent mechanical properties compared to membranes from other bird species, emerging as a potential natural scaffold candidate. Coupled with platelet-rich plasma (PRP), known for its regenerative properties, ESM holds promise for improving tendon repair. This study aims to evaluate the biocompatibility and efficacy of an ESM-PRP scaffold in treating Achilles tendon ruptures, employing in vitro and in vivo assessments to gauge its potential in tendon regeneration in living organisms. Ostrich ESM was prepared from pathogen-free ostrich eggs, sterilized with UV radiation and prepared in desired dimensions before implantation (1.5 × 1 cm). High-resolution scanning electron microscopy (HRSEM) was utilized to visualize the sample morphology and fiber bonding. In vitro biocompatibility was assessed using the MTT assay and DAPI staining, while in vivo biocompatibility was evaluated in a rat model. For the in vivo Achilles tendinopathy assay, rats were divided into groups and subjected to AT rupture followed by treatment with ESM, PRP, or a combination. SEM was employed to evaluate tendon morphology, and real-time PCR was conducted to analyze gene expression levels. The in vivo assay indicated that the ESM scaffold was safe for an extended period of 8 weeks, showing no signs of inflammation based on histopathological analysis. In the Achilles tendon rupture model, combining ESM with PRP enhanced tendon healing after 14 weeks post-surgery. This finding was supported by histopathological, morphological, and mechanical evaluations of tendon tissues compared to normal tendons, untreated tendinopathy, and injured tendons treated with the ESM scaffold. Gene expression analysis revealed significantly increased expression of Col1a1, Col3a1, bFGF, Scleraxis (Scx), and tenomodulin in the ESM-PRP groups. The findings of our study demonstrate that the combination of Ostrich ESM with PRP significantly enhances AT repair and is a biocompatible scaffold for the application in living organisms.

Exploring the applications of platelet-rich plasma in tissue engineering and regenerative medicine: evidence from goat and sheep experimental research

Platelet-rich plasma (PRP) has emerged as a promising therapeutic approach in regenerative medicine. It contains various growth factors and bioactive molecules that play pivotal roles in tissue repair, regeneration, and inflammation modulation. This comprehensive narrative review delves into the therapeutic potential of PRP in experimental goat and sheep research, exploring recent advancements, challenges, and future prospects in the field. PRP has been explored for its application in musculoskeletal injuries, wound healing, and orthopedic conditions. Studies have demonstrated the ability of PRP to accelerate tissue healing, reduce inflammation, and improve the overall quality of healing. Recent advancements in PRP technology have led to the development of novel formulations and delivery methods to enhance its therapeutic efficacy. PRP has shown promise in tendon and ligament injuries, osteoarthritis, and bone fractures in experimental goat and sheep research. Despite these advancements, several challenges and opportunities exist to harness the full therapeutic potential of PRP in regenerative medicine. Standardizing PRP preparation protocols, including blood collection techniques, centrifugation parameters, and activation methods, is essential to ensure consistency and reproducibility of the findings. Moreover, further research is needed to elucidate the optimal dosing, frequency, and timing of PRP administration for different clinical indications. Research conducted in goat and sheep models provides evidence supporting the translational potential of PRP in tissue engineering and regenerative medicine. By harnessing the regenerative properties of PRP and leveraging insights from preclinical studies, researchers can develop innovative therapeutic strategies to address unmet clinical needs and improve patient outcomes in diverse medical specialties.

Platelet-Rich Plasma: A Promising Regenerative Therapy in Gynecological Disorders

Platelet-rich plasma (PRP) could be understood as a special preparation of plasma in which the concentration of platelet is immensely high. This rationale for plasma use has been in the medical science for many years with plenty of success in various fields where it was inculcated, bringing dramatically favorable and better outcomes in terms of disease management and prognosis. PRP has been widely used in orthopedics from the very beginning, but in the past few years its use has been extended to other fields too, such as obstetrics and gynecology. From the very onset of the introduction of platelet-rich plasma in gynecology, there had been constant research being carried out all around the globe in order to scientifically prove and confirm its exact role in the management of gynecological problems. Regenerative medicine in gynecology was among the first areas where the platelet-rich plasma was implemented and has substantially given great results, which encouraged further extensive research to be carried out in other spectrums of gynecology. The implications of such great struggles ultimately gave way to evidence suggesting the importance of platelet-rich plasma in managing gynecological disorders like Asherman’s syndrome, urinary incontinence, genital fistulas, thin endometrium, etc. This review article collectively summarizes the various use of platelet-rich plasma in gynecology.

Do platelet concentrates accelerate orthodontic tooth movement?: a systematic review

PURPOSE

Surgical techniques in orthodontics have received widespread attention in recent years. Meanwhile, biomaterials with high molecular content have been introduced, such as platelet concentrates (PCs), which may accelerate orthodontic tooth movement (OTM) and reduce periodontal damage. The present systematic review aimed to answer the following PICO question: "In patients in whom orthodontic surgical techniques are performed (P), what is the effectiveness of using PCs over the surgical site (I) when compared to not placing PCs (C) to achieve faster tooth movement (O)?"

METHODS

A search was performed in 6 databases. The criteria employed were those described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses declaration. The present review included studies with a control group that provided information about the influence of PCs on the rate of OTM.

RESULTS

The electronic search identified 10 studies that met the established criteria.

CONCLUSIONS

The included studies were very diverse, making it difficult to draw convincing conclusions. However, a tendency was observed for OTM to be accelerated when PCs were used as an adjuvant for canine distalization after premolar extraction when distalization was started in the same session. Likewise, studies seem to indicate an association between PC injection and the amount of canine retraction. However, it is not possible to affirm that the use of PCs in corticotomy shortens the overall treatment time, as this question has not been studied adequately.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42021278542.

Comparison of single platelet-rich plasma injection with hyaluronic acid injection for partial-thickness rotator cuff tears

BACKGROUND

Partial-thickness rotator cuff tears (PTRCTs) is not uncommon, and various nonsurgical injection therapy for PTRCTs emerged. Platelet-rich plasma (PRP) and hyaluronic acid (HA) injection were proposed for treating PTRCTs; however, the relation of dose among injectates was still lacking.

METHODS

This was a prospective, nonrandomized, comparative study. The aim of the study was to compare the effects of ultrasound-guided single PRP injection with three doses of HA injection, combination of postinjection rehabilitation, for treating PTRCTs. Subjects received either ultrasound-guided PRP injection and rehabilitation exercise, or ultrasound-guided subacromial HA injection and rehabilitation exercise. Shoulder Pain and Disability Index (SPADI), range of motion (ROM), pain visual analog scale (VAS), and Constant-Murley Shoulder Score (CMSS) were recorded before injection, and at 1 and 3 months after injection.

RESULTS

Forty-eight patients were enrolled. They received either ultrasound-guided single PRP (n = 24) intralesional and peritendinous injection or three doses of HA (n = 24) subacromial injection plus rehabilitation exercise. In the PRP group, SPADI scores, VAS scores, CMSS significantly improved at 1-month and 3-month follow up; flexion and abduction ROM significantly increased at 3-month follow up. In the HA group, SPADI scores, VAS during overhead activities, VAS night pain, and CMSS significantly improved in the first and third months; flexion and active abduction ROM significantly increased in the third month. The PRP group revealed significantly better passive abduction ROM and CMSS at third month than HA group.

CONCLUSION

Ultrasound-guided single PRP injection exhibited comparable benefit to three doses of HA injection in patients with PTRCTs short-termly, with an extended effect regarding passive shoulder abduction ROM and CMSS.

Growth Factor Roles in Soft Tissue Physiology and Pathophysiology

Repair and healing of injured and diseased tendons has been traditionally fraught with apprehension and difficulties, and often led to rather unsatisfactory results. The burgeoning research field of growth factors has opened new venues for treatment of tendon disorders and injuries, and possibly for treatment of disorders of the aorta and major arteries as well. Several chapters in this volume elucidate the role of transforming growth factor β (TGFß) in pathogenesis of several heritable disorders affecting soft tissues, such as aorta, cardiac valves, and tendons and ligaments. Several members of the bone morphogenetic group either have been approved by the FDA for treatment of non-healing fractures or have been undergoing intensive clinical and experimental testing for use of healing bone fractures and tendon injuries. Because fibroblast growth factors (FGFs) are involved in embryonic development of tendons and muscles among other tissues and organs, the hope is that applied research on FGF biological effects will lead to the development of some new treatment strategies providing that we can control angiogenicity of these growth factors. The problem, or rather question, regarding practical use of imsulin-like growth factor I (IGF-I) in tendon repair is whether IGF-I acts independently or under the guidance of growth hormone. FGF2 or platelet-derived growth factor (PDGF) alone or in combination with IGF-I stimulates regeneration of periodontal ligament: a matter of importance in Marfan patients with periodontitis. In contrast, vascular endothelial growth factor (VEGF) appears to have rather deleterious effects on experimental tendon healing, perhaps because of its angiogenic activity and stimulation of matrix metalloproteinases-proteases whose increased expression has been documented in a variety of ruptured tendons. Other modalities, such as local administration of platelet-rich plasma (PRP) and/or of mesenchymal stem cells have been explored extensively in tendon healing. Though treatment with PRP and mesenchymal stem cells has met with some success in horses (who experience a lot of tendon injuries and other tendon problems), the use of PRP and mesenchymal stem cells in people has been more problematic and requires more studies before PRP and mesenchymal stem cells can become reliable tools in management of soft tissue injuries and disorders.

Comparison of the effects of platelet-rich plasma and dexamethasone ınjection on scar formation after vocal fold ınjury in rabbits

OBJECTIVES

In this study, a histopathological comparison was aimed between platelet-rich plasma (PRP) injection and dexamethasone injection in the prevention of scar formation after vocal fold injury.

MATERIALS AND METHODS

Electrocautery was applied to damage the right and left vocal folds of a total of 12 New Zealand rabbits. PRP obtained from the rabbit's own blood was injected into the right vocal fold, and dexamethasone was injected into the left vocal fold. After 8 weeks, the experimental animals were euthanized, and the levels of inflammatory cell infiltration, vascularization, collagen, elastin, and hyaluronic acid (HA) were compared in histopathological evaluation.

RESULTS

In statistical comparison of histopathological data obtained; in terms of plasma cell infiltration, vascularization, and edema parameters, statistically significant results were obtained in favor of the PRP group. Although the difference between collagen, elastin and HA, which are critical in vocal fold scar healing, was more positive in favor of PRP, no significant result was revealed in the statistical evaluation.

CONCLUSIONS

PRP injection in rabbits with vocal fold damage reveals similar characteristics with dexamethasone injection in preventing scar formation. PRP injection has favorable effects on vascularization, prevention of edema, and number of plasma cells.

Early Clinical and Functional Outcome of Rotator Cuff Tendinopathy of the Shoulder Treated with Platelet Rich Plasma Injection

Introduction:

Rotator cuff tendinitis has been treated using various methods including physiotherapy, steroid injections and recently platelet rich plasma (PRP). Most of these methods aim at giving symptomatic relief rather than addressing the pathology. There is no clear consensus over the benefit of using PRP for tendinitis. We decided to do a prospective clinical study to demonstrate the efficacy of PRP and study the functional outcome in the treatment of rotator cuff tendinopathy.

Material and Methods:

Patients with shoulder pain for more than three months not responding to NSAIDs or physiotherapy with a diagnosis of rotator cuff tendinitis, confirmed by MRI, were included in the study. Patients with rotator cuff tear or any other shoulder pathology were excluded. We included a total of 30 patients who received 5ml of landmark guided PRP injection in the subacromial space followed by a six-week exercise program. Patients were followed-up at 3, 6 and 12 weeks. and were assessed clinically using the VAS, SPADI and Constant and Murley Score.

Results:

VAS score of patients improved from a pre injection score of 7.4 to a score of 1.9 in the 12th week. The mean SPADI score and Constant score improved from a pre injection score of 73.33 and 39.57 to a post injection score of 18.1 and 86.47, respectively.

Conclusion:

Platelet Rich Plasma injections showed good to excellent early results, in patients with rotator cuff tendinopathy with improvement in VAS, SPADI and Constant scores.

Clinical Outcomes of Meniscus Repair with or without Multiple Intra-Articular Injections of Platelet Rich Plasma after Surgery

Preservation of the meniscal volume is crucial in meniscus repair. The goal of this study was to evaluate the clinical outcome of repeated intra-articular platelet-rich plasma (PRP) injections after arthroscopic repair of a traumatic meniscal tear. We retrospectively reviewed 61 primary meniscal repairs in 61 patients (PRP group: 30; non-PRP: 31) from 2017 to 2018. Patients in the PRP group received repeated intra-articular PRP injections in week 2,4,6 after the primary meniscus repair. Subsequent meniscal repair treatment or meniscectomy, knee arthroplasty, and IKDC changes of less than 11.5 points were defined as healing failures. After following up for at least 24 months, the IKDC score was 75.1 ± 13.6, and the Lysholm score was 80.6 ± 14.9 in the PRP group and 72.6 ± 15.8 (IKDC) and 77.7 ± 17.2 (Lysholm) in the non-PRP group. Healing rates of the PRP and the non-PRP groups were 93.3% (Kaplan-Meier 91.6%) and 87.1% (Kaplan-Meier 84.7%), respectively (log rank test p = 0.874). Our study is the first to use multiple intra-articular PRP injections to facilitate meniscal healing after meniscal repair. Though selection bias may be present in this study, the PRP group had similar functional outcome and healing rate compared to non-PRP group.

Assessment of the effects of local platelet-rich fibrin injection and piezocision on orthodontic tooth movement during canine distalization

INTRODUCTION

The study aimed to evaluate and compare the effects of local platelet-rich fibrin (PRF) injection and piezocision applications on tooth movement during canine distalization, as well as to evaluate any changes in the periodontal parameters.

METHODS

Twenty-four patients were randomly divided into 2 groups. A randomly selected side of the maxillary arch received either PRF injection (PRF group) or piezocision (piezocision group). The contralateral sides of both groups served as the controls. After piezocision and PRF injection applications, canine distalization was initiated in both groups with a 150 g force. Patients were followed every 2 weeks for a total 12 of weeks. The following variables were evaluated: cephalometric measurements, the amount of canine distalization, molar mesialization, canine rotation, transversal changes in dental models, and periodontal parameters.

RESULTS

The amount of canine distal movement was found to be greater in the experimental sides than in the control sides in both groups at 12 weeks (P <0.05). There were no differences in the amount of molar mesialization, canine rotation, or transversal measurements in both groups when compared with the experimental sides with the control sides (P >0.05). There were no differences in the skeletal measurements or periodontal parameters in both groups (P >0.05). In both groups, the maxillary incisors were retroclined and retracted.

CONCLUSIONS

PRF and piezocision accelerated tooth movement, but there were no differences between the 2 applications in terms of speed, amount, duration of tooth movement, or periodontal parameters during canine distalization.

Stem Cells and Platelet-rich Plasma for Knee Osteoarthritis: Prevalence and Cost in South Florida

INTRODUCTION

The use of stem cell therapy (SCT) and platelet-rich plasma (PRP) injection for knee osteoarthritis (OA) is extremely controversial and at best experimental stage. These treatments are being offered across the nation for "cash-only payments." Our objectives were to determine (1) what proportion of board-certified orthopedic surgeons in Miami-Dade County offer SCT or PRP and (2) how much do practices charge for these services.

METHODS

All board-certified orthopedic surgeons' offices in Miami-Dade County were identified by their American Academy of Orthopaedic Surgeons active membership. Offices were contacted and presented a hypothetical patient with end-stage OA searching for treatment (SCT or PRP injections) before having to undergo surgery.

RESULTS

Of the 96 registered American Academy of Orthopaedic Surgeons member's offices, 91 (94.7%) were contacted, 36% of offices offered PRP, and 24.5% offered SCT. However, 81% of the offices were transparent on the pricing of PRP, whereas 42% gave a price for SCT. Remaining practices stated that pricing would be "determined or discussed" during a scheduled visit. Mean cost for PRP injection was $897 (range, $350 to $1,700), and for SCT injection, it was $3,100 (range, $1,200 to $6,000).

DISCUSSION

Biological injectables as treatment of knee OA have potential use in the nonsurgical management of this disease. Data on the effectiveness are lacking and are conflicting. Data should continue to be investigational.

LEVEL OF EVIDENCE

Level IV.

Acute Lateral Ankle Instability

Acute injuries to the lateral ankle complex remain common and account for 20% to 25% of musculoskeletal injuries. Initial assessment should use the Ottawa ankle rules, and grading should take into account degree of mechanical instability. Nonoperative measures are preferable for all grades of injury; however, mechanical instability is a predictor for resprains. Functional treatment after a short period of relative immobilization gives satisfactory results, and residual chronic ankle instability can be managed by repair or reconstruction. Delayed physical examination in elite athletes, along with 3T MRI, may be helpful in making a case for early surgical stabilization.

Ethics, Evidence Based Sports Medicine, and the Use of Platelet Rich Plasma in the English Premier League

The use of platelet rich plasma (PRP) as a novel treatment is discussed in the context of a qualitative research study comprising 38 interviews with sports medicine practitioners and other stakeholders working within the English Premier League during the 2013-16 seasons. Analysis of the data produced several overarching themes: conservatism versus experimentalism in medical attitudes; therapy perspectives divergence; conflicting versions of appropriate evidence; subcultures; community beliefs/practices; and negotiation of medical decision-making. The contested evidence base for the efficacy of PRP is presented in the context of a broader professional shift towards evidence based medicine within sports medicine. Many of the participants while accepting this shift are still committed to casuistic practices where clinical judgment is flexible and does not recognize a context-free hierarchy of evidentiary standards to ethically justifiable practice. We also discuss a tendency in the data collected to consider the use of deceptive, placebo-like, practices among the clinician participants that challenge dominant understandings of informed consent in medical ethics. We conclude that the complex relation between evidence and ethics requires greater critical scrutiny for this emerging specialism within the medical community.

Potential Usefulness of Losartan as an Antifibrotic Agent and Adjunct to Platelet-Rich Plasma Therapy to Improve Muscle Healing and Cartilage Repair and Prevent Adhesion Formation

Postoperative tissue fibrosis represents a major complication in orthopedics. Transforming growth factor beta 1 is a key molecule in the development of postoperative fibrosis. High concentrations of transforming growth factor beta 1 have also been implicated in various diseases. Agents that counteract the actions of transforming growth factor beta 1 have been investigated as potential antifibrotic medications and as adjunct treatment to platelet-rich plasma injections (increased amounts of transforming growth factor beta 1) to improve their effectiveness and/or safety profile. Losartan blocks transforming growth factor beta 1 action and has attracted special interest in orthopedic research that focuses on how to reduce the risk of postoperative fibrosis. [Orthopedics. 2018; 41(5):e591-e597.].

Anterior disc derangement with reduction of the temporomandibular joint: a case report

Background

Temporomandibular dysfunction involving anterior disc derangement with or without reduction, secondary to posterior ligament insufficiency is typically managed conservatively with success in a majority of patients. When conservative management fails, the next step in the continuum of care is unclear. Platelet-rich plasma injection combined with a 3-week immobilization period may be effective in treating posterior ligament insufficiency following a period of physical therapy. The result of this case was exceptionally successful, with the patient reporting 100% improvement 6 months post-injection. Prior to this case, we predicted a 20% success rate based on her inability to maintain the effects of conservative management over the long term.

Case presentation

A 33-year-old white woman presented with temporomandibular dysfunction, which responded to an initial course of physical therapy aimed at restoring the mechanics of her temporomandibular joint, exercise management, and education on self-management strategies. She returned 20 months later and responded well to another course of physical therapy. Despite improvement in pain, range of motion, and mechanics, she continued to present with a reduction click at the end range of opening. The crisp and loud nature of the reduction click indicated a viable posterior ligament and reduction of the anteriorly displaced disc. She opted for platelet-rich plasma injection, provided by a chronic pain specialist with the assistance of a physical therapist. She was immobilized for 3 weeks, followed by a weaning period with reduced posterior support for an additional 5 weeks. Follow-up appointments with a physical therapist occurred at 3 weeks, 8 weeks, and 6 months post-injection.

Conclusions

At 6 months, she reported 100% improvement. Objectively, there was no indication that the disc condyle relationship was disrupted. At 6 months post-platelet-rich plasma injection, preceded by a period of conservative physical therapy management, and followed with appropriate physical therapy follow-up, this individual had complete resolution of her anterior disc derangement with reduction.

Electronic supplementary material

The online version of this article (10.1186/s13256-018-1637-8) contains supplementary material, which is available to authorized users.

Platelet Rich Plasma and Hyaluronic Acid Blend for the Treatment of Osteoarthritis: Rheological and Biological Evaluation

Introduction

Osteoarthritis (OA) is the most common musculoskeletal disease. Current treatments for OA are mainly symptomatic and inadequate since none results in restoration of fully functional cartilage. Hyaluronic Acid (HA) intra-articular injections are widely accepted for the treatment of pain associated to OA. The goal of HA viscosupplementation is to reduce pain and improve viscoelasticity of synovial fluid. Platelet-rich plasma (PRP) has been also employed to treat OA to possibly induce cartilage regeneration. The combination of HA and PRP could supply many advantages for tissue repair. Indeed, it conjugates HA viscosupplementation with PRP regenerative properties. The aim of this study was to evaluate the rheological and biological properties of different HA compositions in combination with PRP in order to identify (i) the viscoelastic features of the HA-PRP blends, (ii) their biological effect on osteoarthritic chondrocytes and (iii) HA formulations suitable for use in combination with PRP.

Materials and Methods

HA/PRP blends have been obtained mixing human PRP and three different HA at different concentrations: 1) Sinovial, 0.8% (SN); 2) Sinovial Forte 1.6% (SF); 3) Sinovial HL 3.2% (HL); 4) Hyalubrix 1.5% (HX). Combinations of phosphate buffered saline (PBS) and the four HA types were used as control. Rheological measurements were performed on an Anton PaarMCR-302 rheometer. Amplitude sweep, frequency sweep and rotational measurements were performed and viscoelastic properties were evaluated. The rheological data were validated performing the tests in presence of Bovine Serum Albumin (BSA) up to ultra-physiological concentration (7%). Primary osteoarthritic chondrocytes were cultured in vitro with the HA and PRP blends in the culture medium for one week. Cell viability, proliferation and glycosaminoglycan (GAG) content were assessed.

Results

PRP addition to HA leads to a decrease of viscoelastic shear moduli and increase of the crossover point, due to a pure dilution effect. For viscosupplements with HA concentration below 1% the viscoelasticity is mostly lost. Results were validated also in presence of proteins, which in synovial fluid are more abundant than HA.

Chondrocytes proliferated overtime in all different culture conditions. The proliferation rate was higher in chondrocytes cultured in the media containing PRP compared to the cultures with different HA alone. GAG content was significantly higher in chondrocytes cultured in PRP and HL blend.

Discussion

We investigated the rheological and biological properties of four different HA concentrations when combined with PRP giving insights on viscoelastic and biological properties of a promising approach for future OA therapy. Our data demonstrate that PRP addition is not detrimental to the viscosupplementation effect of HA. Viscosupplements containing low HA concentration are not indicated for combination with PRP, as the viscoelastic properties are lost. Although having the same rheological behavior of SF and HX, HL was superior in stimulating extracellular matrix production in vitro.

The Effect of Autologous Platelet Rich Plasma in the Treatment of Achilles Tendon Ruptures: An Experimental Study on Rabbits

BACKGROUND

Achilles tendon ruptures are characterized by a long recovery period, high re-rupture rate and late return to work. To overcome these difficulties and augment tendon repair, many agents have been used.

AIMS

To determine the effect of autologous platelet rich plasma (PRP) in the treatment of Achilles tendon ruptures in rabbits.

STUDY DESIGN

Animal experimentation.

METHODS

The study included 14 New Zealand albino rabbits that were divided randomly into 2 groups, A and B, each containing seven rabbits. On day zero, all 28 Achilles tendons were tenotomized and repaired. In group A, the tendons were injected with PRP post-surgery, whereas those in group B were left untreated. On day 28, the right tendons in both groups were examined histopathologically via both light and electron microscopy, and the left tendons were subjected to biomechanical testing.

RESULTS

The histological and biomechanical findings in both light and electron microscopy in group A were better than those in group B, but the difference was not significant. According to Tang's scale, the mean value in Group A was 3.57, while it was 3.0 in Group B. The mean value of Group A for the length of collagen bands was 48.09 nm while the mean value of Group B was 46.58 nm (p=0.406). In biomechanical tests, although stiffness values were higher in group A, the difference between groups was not significant. In addition, maximum load values did not differ between groups A and B.

CONCLUSION

PRP had no effect on the healing process 28 days post-Achilles tendon rupture.

Patterns of platelet-rich plasma use among Australasian sports physicians

Background

We hypothesised that the application, production and administration of platelet-rich plasma (PRP) varies widely among sports physicians, bringing into question the validity and consistency of PRP described in research and clinical use. We also assessed congruence between the reported clinical indications for PRP, and the available research evidence for these indications.

Methods

We conducted an anonymous 23 question online survey of 153 current Fellows of the Australasian College of Sports Physicians (ACSP), using an emailed link. It was opened from April 2014 until August 2014.

Results

The survey confirmed that there is wide variation in the application, production and administration of PRP. Over one-third (38%) of sports physicians performed PRP injections themselves. Almost half of clinicians (49%) did not provide the service themselves, and only referred for PRP injections. The remaining clinicians did not inject PRP or refer for PRP injections at all. Clinicians who provided PRP injections varied from an average of 0–500 injections per month, with a median of 12 times per month. Australian sports physicians were far more likely to use PRP than their New Zealand counterparts. For sports physicians who provided or referred for PRP injections, tendinopathy was overwhelmingly cited (n=63) as the condition for which clinicians thought PRP was most effective. 30 respondents cited effectiveness for osteoarthritis.

Conclusions

This study confirms that there is no clear consensus among sports physicians on the preparation, administration or best clinical indications for PRP.

Platelet-rich plasma in orthopedic therapy: a comparative systematic review of clinical and experimental data in equine and human musculoskeletal lesions

BACKGROUND

This systematic review aimed to present and critically appraise the available information on the efficacy of platelet rich plasma (PRP) in equine and human orthopedic therapeutics and to verify the influence of study design and methodology on the assumption of PRP's efficacy. We searched Medline, PubMed, Embase, Bireme and Google Scholar without restrictions until July 2013. Randomized trials, human cohort clinical studies or case series with a control group on the use of PRP in tendons, ligaments or articular lesions were included. Equine clinical studies on the same topics were included independently of their design. Experimental studies relevant to the clarification of PRP's effects and mechanisms of action in tissues of interest, conducted in any animal species, were selected.

RESULTS

This review included 123 studies. PRP's beneficial effects were observed in 46.7% of the clinical studies, while the absence of positive effects was observed in 43.3%. Among experimental studies, 73% yielded positive results, and 7.9% yielded negative results. The most frequent flaws in the clinical trials' designs were the lack of a true placebo group, poor product characterization, insufficient blinding, small sampling, short follow-up periods, and adoption of poor outcome measures. The methods employed for PRP preparation and administration and the selected outcome measures varied greatly. Poor study design was a common feature of equine clinical trials. From studies in which PRP had beneficial effects, 67.8% had an overall high risk of bias. From the studies in which PRP failed to exhibit beneficial effects, 67.8% had an overall low risk of bias.

CONCLUSIONS

Most experimental studies revealed positive effects of PRP. Although the majority of equine clinical studies yielded positive results, the human clinical trials' results failed to corroborate these findings. In both species, beneficial results were more frequently observed in studies with a high risk of bias. The use of PRP in musculoskeletal lesions, although safe and promising, has still not shown strong evidence in clinical scenarios.

Ultrasound-guided platelet-rich plasma injection for distal biceps tendinopathy

BACKGROUND

Distal biceps tendinopathy is an uncommon cause of elbow pain. The optimum treatment for cases refractory to conservative treatment is unclear. Platelet-rich plasma has been used successfully for other tendinopathies around the elbow.

METHODS

Six patients with clinical and radiological evidence of distal biceps tendinopathy underwent ultrasound-guided platelet-rich plasma (PRP) injection. Clinical examination findings, visual analogue score (VAS) for pain and Mayo Elbow Performance scores were recorded.

RESULTS

The Mayo Elbow Performance Score improved from 68.3 (range 65 to 85) (fair function) to 95 (range 85 to 100) (excellent function). The VAS at rest improved from a mean of 2.25 (range 2 to 5) pre-injection to 0. The VAS with movement improved from a mean of 7.25 (range 5 to 8) pre-injection to 1.3 (range 0 to 2). No complications were noted.

DISCUSSION

Ultrasound-guided PRP injection appears to be a safe and effective treatment for recalcitrant cases of distal biceps tendinopathy. Further investigation with a randomized controlled trial is needed to fully assess its efficacy.

Progress in cell-based therapies for tendon repair

The last decade has seen significant developments in cell therapies, based on permanently differentiated, reprogrammed or engineered stem cells, for tendon injuries and degenerative conditions. In vitro studies assess the influence of biophysical, biochemical and biological signals on tenogenic phenotype maintenance and/or differentiation towards tenogenic lineage. However, the ideal culture environment has yet to be identified due to the lack of standardised experimental setup and readout system. Bone marrow mesenchymal stem cells and tenocytes/dermal fibroblasts appear to be the cell populations of choice for clinical translation in equine and human patients respectively based on circumstantial, rather than on hard evidence. Collaborative, inter- and multi-disciplinary efforts are expected to provide clinically relevant and commercially viable cell-based therapies for tendon repair and regeneration in the years to come.

State-of-the-Art management of knee osteoarthritis

Osteoarthritis (OA) is the most common type of arthritis found in the United States' population and is also the most common disease of joints in adults throughout the world with the knee being the most frequently affected of all joints. As the United States' population ages along with the increasing trends in obesity prevalence in other parts of the world, it is expected that the burden of OA on the population, healthcare system, and overall economy will continue to increase in the future without making major improvements in managing knee OA. Numerous therapies aim to reduce symptoms of knee OA and continued research has helped to further understand the complex pathophysiology of its disease mechanism attempting to uncover new potential targets for the treatment of OA. This review article seeks to evaluate the current practices for managing knee OA and discusses emerging therapies on the horizon. These practices include non-pharmacological treatments such as providing patient education and self-management strategies, advising weight loss, strengthening programs, and addressing biomechanical issues with bracing or foot orthoses. Oral analgesics and anti-inflammatories are pharmacologicals that are commonly used and the literature overall supports that some of these medications can be helpful for managing knee OA in the short-term but are less effective for long-term management. Additionally, more prolonged use significantly increases the risk of serious associated side effects that are not too uncommon. Disease-modifying osteoarthritis drugs are being researched as a treatment modality to potentially halt or slow disease progression but data at this time is limited and continued studies are being conducted to further investigate their effectiveness. Intra-articular injectables are also implemented to manage knee OA ranging from corticosteroids to hyaluronans to more recently platelet-rich plasma and even stem cells while several other injection therapies are presently being studied. The goal of developing new treatment strategies for knee OA is to prolong the need for total knee arthroplasty which should be utilized only if other strategies have failed. High tibial osteotomy and unicompartmental knee arthroplasty are potential alternatives if only a single compartment is involved with more data supporting unicompartmental knee arthroplasty as a good treatment option in this scenario. Arthroscopy has been commonly used for many years to treat knee OA to address degenerative articular cartilage and menisci, however, several high-quality studies have shown that it is not a very effective treatment for the majority of cases and should generally not be considered when managing knee OA. Improving the management of knee OA requires a multi-faceted treatment approach along with continuing to broaden our understanding of this complex disease so that therapeutic advancements can continue to be developed with the goal of preventing further disease progression and even potentially reversing the degenerative process.

Sonographically Guided Anterior Cruciate Ligament Injection: Technique and Validation

OBJECTIVE

To describe and validate a practical technique for sonographically guided anterior cruciate ligament (ACL) injections.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Procedural skills laboratory in a tertiary medical center.

SUBJECTS

Ten unembalmed, cadaveric mid-thigh-knee-ankle foot specimens (5 left knees and 5 right knees; 5 male and 5 female) from 10 donors aged 76 to 93 years (mean 85.6 years) with body mass indices of 17.6 to 42.2 kg/m(2) (mean 28.8 kg/m(2)).

METHODS

A single, experienced operator used a 22-gauge, 63.5-mm stainless steel needle and a 12-3-MHz linear transducer to inject 1.5 mL of diluted colored latex into the ACLs of 10 unembalmed cadaveric specimens via an in-plane, caudad-to-cephalad approach, long axis to the ACL. At a minimum of 24 hours postinjection, specimens were dissected, and the presence and distribution of latex within the ACL assessed by a study co-investigator.

MAIN OUTCOME

Presence and distribution of latex within the ACL.

RESULTS

All 10 injections accurately delivered latex into the proximal (femoral), midsubstance, and distal (tibial) portions of the ACL. No specimens exhibited evidence of needle injury or latex infiltration with respect to the menisci, hyaline cartilage, or posterior cruciate ligament.

CONCLUSIONS

Sonographically guided intra-ligamentous ACL injections are technically feasible and can be performed with a high degree of accuracy. Sonographically guided ACL injections could be considered for research and clinical purposes to directly deliver injectable agents into the healing ACL postinjury or postreconstruction.

Effects of repetitive platelet-rich plasma application on human tenocyte proliferation

Current clinical application of platelet-rich plasma is showing a trend toward multiple treatments. The goal of this study was to show the benefit of interval platelet-rich plasma application in the healing and recovery of human tenocytes using an in vitro cell model. Eight volunteers (6 men and 2 women) were included in this study (mean±SD age, 31.6±10.9 years). Venous blood was collected from new blood draws at 3 different times. Two blood products were prepared on each day of treatment: platelet-rich plasma derived from a single-spin process (PRPSS) and platelet-rich plasma derived from a double-spin process (PRPDS). The study had 2 limbs: 2-day and 4-day intervals. Cell proliferation, measured as disintegrations per minute, was then examined via a radioactive thymidine assay. In the 2-day-interval group, the difference in disintegrations per minute between days 0 and 2 in the PRPSS group reached statistical significance (P =.006). In the PRPDS group, statistical difference was seen between days 0 and 4 (P=.001) and between days 2 and 4 (P=.030). In the 4-day-interval group, the difference in disintegrations per minute between days 4 and 8 in the PRPSS group reached statistical significance, showing a decrease in cell proliferation (P =.013). In the PRPDS group, a statistical difference was seen between days 0 and 8 (P=.021), also showing a decrease in cell proliferation. The greatest effect of platelet-rich plasma, which has a positive effect on tenocyte proliferation and recovery, is seen on initial application. Its effect is diminished with repetitive application, and this finding leads to questioning of the efficacy of interval platelet-rich plasma dosing.

Platelet-rich plasma and adipose-derived mesenchymal stem cells for regenerative medicine-associated treatments in bottlenose dolphins (Tursiops truncatus)

Dolphins exhibit an extraordinary capacity to heal deep soft tissue injuries. Nevertheless, accelerated wound healing in wild or captive dolphins would minimize infection and other side effects associated with open wounds in marine animals. Here, we propose the use of a biological-based therapy for wound healing in dolphins by the application of platelet-rich plasma (PRP). Blood samples were collected from 9 different dolphins and a specific and simple protocol which concentrates platelets greater than two times that of whole blood was developed. As opposed to a commonly employed human protocol for PRP preparation, a single centrifugation for 3 minutes at 900 rpm resulted in the best condition for the concentration of dolphin platelets. By FACS analysis, dolphin platelets showed reactivity to platelet cell-surface marker CD41. Analysis by electron microscopy revealed that dolphin platelets were larger in size than human platelets. These findings may explain the need to reduce the duration and speed of centrifugation of whole blood from dolphins to obtain a 2-fold increase and maintain proper morphology of the platelets. For the first time, levels of several growth factors from activated dolphin platelets were quantified. Compared to humans, concentrations of PDGF-BB were not different, while TGFβ and VEGF-A were significantly lower in dolphins. Additionally, adipose tissue was obtained from cadaveric dolphins found along the Spanish Mediterranean coast, and adipose-derived mesenchymal stem cells (ASCs) were successfully isolated, amplified, and characterized. When dolphin ASCs were treated with 2.5 or 5% dolphin PRP they exhibited significant increased proliferation and improved phagocytotic activity, indicating that in culture, PRP may improve the regenerative capacity of ASCs. Taken together, we show an effective and well-defined protocol for efficient PRP isolation. This protocol alone or in combination with ASCs, may constitute the basis of a biological treatment for wound-healing and tissue regeneration in dolphins.

Evaluation of pain regression in patients with temporomandibular dysfunction treated by intra-articular platelet-rich plasma injections: a preliminary report

OBJECTIVE

The objective of this study was to evaluate the regression of temporomandibular pain as a result of intra-articular injections of platelet-rich plasma (PRP) to patients with temporomandibular joint dysfunction previously subjected to prosthetic treatment.

MATERIALS AND METHODS

The baseline study material consisted of 10 patients, both males and females, aged 28 to 53 years, previously treated due to painful temporomandibular joint dysfunction using occlusal splints. All patients were carried out to a specialist functional assessment of the dysfunction using the Polish version of the RDC/TMD questionnaire axis I and II. Intra-articular injections were preceded by a preparation of PRP. The injection sites were determined by the method used during arthroscopic surgical procedures. Following aspiration, 0.5 mL of plasma was injected into each temporomandibular joint.

RESULTS

The comparison of the intensity of pain during all examinations suggests a beneficial effect of the procedure being performed as the mean VAS score was 6.5 at examination I, 2.8 at examination II, and 0.6 at examination III.

CONCLUSION

Application of the intra-articular injections of platelet-rich plasma into the temporomandibular joints has a positive impact on the reduction of the intensity of pain experienced by patients treated for temporomandibular joint dysfunction.

Platelet-rich plasma for articular cartilage repair

Platelet concentrates have been gaining popularity for a number of applications in orthopedic surgery as a way to enhance both healing of various tissues and reduce pain. One major area of focus has been the effect of platelet-rich plasma (PRP) on stem cells and chondrocytes and the potential for PRP to enhance cartilage regeneration as well as reduce catabolic factors that lead to cartilage degradation. This article provides an up-to-date review of the current literature regarding the effect of PRP on articular cartilage and its use in the treatment of osteoarthritis. Basic science, animal, and human clinical investigations are presented. In general, PRP has been shown to promote chondrogenic differentiation in vitro and lead to enhanced cartilage repair during animal investigations. Human trials, mostly conducted in the form of injection into knees with osteoarthritis, have shown promise in a number of investigations for achieving symptomatic relief of pain and improving function.

Platelet-rich plasma induces annulus fibrosus cell proliferation and matrix production

PURPOSE

Platelet-rich plasma (PRP) contains growth factors and creates a 3D structure upon clotting; PRP or platelet lysate (PL) might be considered for annulus fibrosus (AF) repair.

METHODS

Bovine AF cells were cultured with 25% PRP, 50% PRP, 25% PL, 50% PL, or 10% FBS. After 2 and 4 days, DNA, glycosaminoglycan (GAG), and mRNA levels were analyzed. Histology was performed after injection of PRP into an AF defect in a whole disc ex vivo.

RESULTS

By day 4, significant increases in DNA content were observed in all treatment groups. All groups also showed elevated GAG synthesis, with highest amounts at 50% PL. Collagen I and II expression was similar between groups; aggrecan, decorin, and versican expression was highest at 25% PL. Injection of PRP into the AF defect resulted in an increased matrix synthesis.

CONCLUSIONS

Platelet-rich preparations increased the matrix production and cell number and may therefore be considered to promote AF repair.

Orthobiologics and platelet rich plasma

Orthobiologics have evolved to the extent that they significantly influence modern orthopedic surgical practice. A better understanding of the role of various growth factors and cells in the process of tendon healing, ligament repair, cartilage regeneration and bone formation has stimulated focused research in many chronic musculoskeletal ailments. Investigators have published results of laboratory as well as clinical studies, using orthobiologics like platelet rich plasma, stem cells, autologous conditioned serum etc., with variable results. However, a clear consensus over the best orthobiologic substance and the method of preparation and usage of these substances is lacking. Much of the confusion is due to the fact that studies ranging from RCTs to case reports present variable results, and the interpretations are wide-ranging. We have reviewed the available orthobiologics related data with a focus on platelet rich plasma in orthopedic conditions.

Effect of platelet-rich plasma and porcine dermal collagen graft augmentation for rotator cuff healing in a rabbit model

BACKGROUND

The rate of healing failure after surgical repair of chronic rotator cuff tears is considerably high.

PURPOSE

To verify the effect of platelet-rich plasma (PRP) with and without porcine dermal collagen graft augmentation on tendon-to-bone healing, using the rabbit supraspinatus tendon.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 80 rabbits were randomly allocated into 4 groups (20 rabbits per group: 12 for histological and 8 for mechanical testing): repair (R), repair + patch augmentation (RPa), repair + PRP (RPr), and repair + patch + PRP (RPaPr). The right shoulder was used for experimental interventions, and the left served as a control. Six weeks after the detachment of the supraspinatus, the torn tendon was repaired in a transosseous manner, simulating double-row repair in all groups. Platelet-rich plasma was prepared and applied onto the repair site in the RPr and RPaPr groups, and the patch was used to augment the repair in the RPa and RPaPr groups. The mechanical tensile strength test was performed at 8 weeks after repair and the histological evaluation at 4 and 8 weeks.

RESULTS

At 4 weeks, the collagen fibers were poorly organized, and fiber continuity was not established in all groups. However, vascularity and cellularity were higher with granulation tissue formation in the PRP-treated groups (RPr and RPaPr) than the nontreated groups (R and RPa). At 8 weeks, tendon-to-bone integration was much improved with more collagen fibers, and longitudinally oriented collagen fibers were visible in all groups. The PRP-treated groups showed better collagen fiber continuity and orientation than the nontreated groups; however, no distinctive difference was found between the patch-augmented groups (RPa and RPaPr) and nonaugmented groups (R and RPr). The mean load-to-failure results were 61.57 ± 29.99 N, 76.84 ± 16.08 N, 105.35 ± 33.82 N, and 117.93 ± 12.60 N for the R, RPa, RPr, and RPaPr groups, respectively, and they were significantly different between the R and RPr (P = .018), R and RPaPr (P = .002), and RPa and RPaPr (P = .029) groups.

CONCLUSION

This animal study showed the enhancement of tendon-to-bone healing after local administration of autologous PRP assessed by histological and biomechanical testing in a rabbit model of chronic rotator cuff tears. However, there was little additive effect of the patch graft.

CLINICAL RELEVANCE

The use of PRP might be a biological supplement to increase the rotator cuff healing rate, which still remains low even after successful cuff repair, but this result should be interpreted with caution regarding clinical applications.

The efficacy of platelet-rich plasma in the treatment of symptomatic knee osteoarthritis: a systematic review with quantitative synthesis

PURPOSE

The purpose of this systematic review was to synthesize the available Level I and Level II literature on platelet-rich plasma (PRP) as a therapeutic intervention in the management of symptomatic knee osteoarthritis (OA).

METHODS

A systematic review of Medline, Embase, Cochrane Central Register of Controlled Trials, PubMed, and www.clinicaltrials.gov was performed to identify all randomized controlled trials and prospective cohort studies that evaluated the clinical efficacy of PRP versus a control injection for knee OA. A random-effects model was used to evaluate the therapeutic effect of PRP at 24 weeks by use of validated outcome measures (Western Ontario and McMaster Universities Arthritis Index, visual analog scale for pain, International Knee Documentation Committee Subjective Knee Evaluation Form, and overall patient satisfaction).

RESULTS

Six Level I and II studies satisfied our inclusion criteria (4 randomized controlled trials and 2 prospective nonrandomized studies). A total of 577 patients were included, with 264 patients (45.8%) in the treatment group (PRP) and 313 patients (54.2%) in the control group (hyaluronic acid [HA] or normal saline solution [NS]). The mean age of patients receiving PRP was 56.1 years (51.5% male patients) compared with 57.1 years (49.5% male patients) for the group receiving HA or NS. Pooled results using the Western Ontario and McMaster Universities Arthritis Index scale (4 studies) showed that PRP was significantly better than HA or NS injections (mean difference, -18.0 [95% confidence interval, -28.8 to -8.3]; P < .001). Similarly, the International Knee Documentation Committee scores (3 studies) favored PRP as a treatment modality (mean difference, 7.9 [95% confidence interval, 3.7 to 12.1]; P < .001). There was no difference in the pooled results for visual analog scale score or overall patient satisfaction. Adverse events occurred more frequently in patients treated with PRP than in those treated with HA/placebo (8.4% v 3.8%, P = .002).

CONCLUSIONS

As compared with HA or NS injection, multiple sequential intra-articular PRP injections may have beneficial effects in the treatment of adult patients with mild to moderate knee OA at approximately 6 months. There appears to be an increased incidence of nonspecific adverse events among patients treated with PRP.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Platelet-rich plasma injections in the treatment of chronic rotator cuff tendinopathy: a randomized controlled trial with 1-year follow-up

BACKGROUND

Rotator cuff tendinopathy (RCT) is a significant source of disability and loss of work. Platelet-rich plasma (PRP) has been suggested to be beneficial in the treatment of RCT.

PURPOSE

To investigate the effect of PRP injections on pain and shoulder functions in patients with chronic RCT.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 40 patients, 18 to 70 years of age, with (1) a history of shoulder pain for >3 months during overhead-throwing activities, (2) MRI findings of RCT or partial tendon ruptures, and (3) a minimum 50% reduction in shoulder pain with subacromial injections of an anesthetic were included in this placebo-controlled, double-blind randomized clinical trial. Patients were randomized into a PRP group (n = 20) or placebo group (n = 20). Patients received an ultrasound-guided injection into the subacromial space that contained either 5 mL of PRP prepared from autologous venous blood or 5 mL of saline solution. All patients underwent a 6-week standard exercise program. Outcome measures (Western Ontario Rotator Cuff Index [WORC], Shoulder Pain and Disability Index [SPADI], 100-mm visual analog scale [VAS] of shoulder pain with the Neer test, and shoulder range of motion) were assessed at baseline and at 3, 6, 12, and 24 weeks and 1 year after injection.

RESULTS

Comparison of the patients revealed no significant difference between the groups in WORC, SPADI, and VAS scores at 1-year follow-up (P = .174, P = .314, and P = .904, respectively). Similar results were found at other assessment points. Within each group, the WORC, SPADI, and VAS scores showed significant improvements compared with baseline at all time points (P < .001). In the range of motion measures, there were no significant group × time interactions.

CONCLUSION

At 1-year follow-up, a PRP injection was found to be no more effective in improving quality of life, pain, disability, and shoulder range of motion than placebo in patients with chronic RCT who were treated with an exercise program.

Augmenting tendon and ligament repair with platelet-rich plasma (PRP)

Tendon and ligament injuries (TLI) commonly occur in athletes and non-athletes alike, and remarkably debilitate patients' athletic and personal abilities. Current clinical treatments, such as reconstruction surgeries, do not adequately heal these injuries and often result in the formation of scar tissue that is prone to re-injury. Platelet-rich plasma (PRP) is a widely used alternative option that is also safe because of its autologous nature. PRP contains a number of growth factors that are responsible for its potential to heal TLIs effectively. In this review, we provide a comprehensive report on PRP. While basic science studies in general indicate the potential of PRP to treat TLIs effectively, a review of existing literature on the clinical use of PRP for the treatment of TLIs indicates a lack of consensus due to varied treatment outcomes. This suggests that current PRP treatment protocols for TLIs may not be optimal, and that not all TLIs may be effectively treated with PRP. Certainly, additional basic science studies are needed to develop optimal treatment protocols and determine those TLI conditions that can be treated effectively.

Efficacy of second intra-tendinous platelet-rich-plasma injection in case of incomplete response of the first injection: three-year follow up experience

PURPOSE

Tendinopathy is a frequent and ubiquitous disease developing early disorganized collagen fibers with neo-angiogenesis on histology. Peritendinous injection of corticosteroid is the commonly accepted strategy despite the absence of inflammation in tendinopathy. Platelet-rich plasma (PRP) might be a useful strategy to rapidly accelerate healing of the tendinopathy but there is a lack ok knowledge about the amount of PRP to be injected and the opportunity of a second injection in case of partial pain relief. The aim of our study was to assess the potential therapeutic effect of early second PRP intra-tendinous to treat persistent painful tendon tear and tendinosis in a long-term follow-up by ultrasonography (US) and clinical data in case of incomplete efficiency of first PRP treatment injection.

MATERIALS AND METHODS

Twenty-four consecutive patients referred for US treatment of tendon tear or tendinosis (T+) were included retrospectively. All had previously received a single intra-tendinous injection of PRP under US guidance (PRPT+) and benefited of a second PRP injection (PRPT2+) under US guidance in order to treat persistent painful. US and clinical data were collected for each anatomic compartment for upper and lower limbs before treatment (D0), 6 weeks (W6) after first treatment, 6 weeks (W12) after second treatment and until 32-month follow-up. We used Mac Nemar test and regression model to compare US and clinical data.

RESULTS

The residual US size of lesions was not significantly lower at W12 after PRPT2+ as compared to W6 (P=0.86 in upper and P=NS in lower member) independently of age (P=0.22), gender (P=0.97) and kind of tendinopathy (P=NS). Quick dash test values and WOMAC values were not significantly lower in PRPT+ at W12 (average: 21.5 months) as compared to W6 (P>0.66) and long-term follow-up (P>0.75) independently of age (P=0.39), gender (P=0.63) and kind of tendinopathy (P=NS). Nevertheless, comparison between D0 and long-term follow-up (LTF) functionnal score was statistically significant (p<0.001 in upper and lower member).

CONCLUSION

Our study suggests that second early intra-tendinous PRP injection under US guidance does not permit rapid decrease of tendinopathy area in US, nor does it quickly improve clinical pain and functional data in case of incomplete efficiency of first PRP injection. However, in long-term follow-up, patients improved their ability to mobilize pathologic tendons.

Does effectiveness of exercise therapy and mobilisation techniques offer guidance for the treatment of lateral and medial epicondylitis? A systematic review

BACKGROUND

Owing to the change in paradigm of the histological nature of epicondylitis, therapeutic modalities as exercises such as stretching and eccentric loading and mobilisation are considered for its treatment.

OBJECTIVE

To assess the evidence for effectiveness of exercise therapy and mobilisation techniques for both medial and lateral epicondylitis.

METHODS

Searches in PubMed, Embase, Cinahl and Pedro were performed to identify relevant randomised clinical trials (RCTs) and systematic reviews. Two reviewers independently extracted data and assessed the methodological quality.

RESULTS

One review and 12 RCTs, all studying lateral epicondylitis, were included. Different therapeutic regimes were evaluated: stretching, strengthening, concentric/eccentric exercises and manipulation of the cervical or thoracic spine, elbow or wrist. No statistical pooling of the results could be performed owing to heterogeneity of the included studies. Therefore, a best-evidence synthesis was used to summarise the results. Moderate evidence for the short-term effectiveness was found in favour of stretching plus strengthening exercises versus ultrasound plus friction massage. Moderate evidence for short-term and mid-term effectiveness was found for the manipulation of the cervical and thoracic spine as add-on therapy to concentric and eccentric stretching plus mobilisation of wrist and forearm. For all other interventions only limited, conflicting or no evidence was found.

CONCLUSIONS

Although not yet conclusive, these results support the belief that strength training decreases symptoms in tendinosis. The short-term analgesic effect of manipulation techniques may allow more vigorous stretching and strengthening exercises resulting in a better and faster recovery process of the affected tendon in lateral epicondylitis.

Overuse injuries

Tendinopathy and chronic tendon issues related to tendinosis are conditions difficult to treat. These conditions often lead to patients' quality of life declining because of the inability to participate in exercise, occupation-related activities, and activities of daily living. By better understanding the pathophysiology related to the development of tendinosis, clinicians will be better able to understand the treatment options available and their limitations while allowing novel therapies to be developed. Conservative treatment of tendinosis starting with a sound rehabilitation program seems to be the best place to start while reserving surgical approaches for cases that have failed conservative management.

MMP inhibition as a potential method to augment the healing of skeletal muscle and tendon extracellular matrix

The extracellular matrix (ECM) of skeletal muscle and tendon is composed of different types of collagen molecules that play important roles in the transmission of forces throughout the body, and in the repair and regeneration of injured tissues. Fibroblasts are the primary cells in muscle and tendon that maintain, repair, and modify the ECM in response to mechanical loading, injury, and inactivity. Matrix metalloproteinases (MMPs) are enzymes that digest collagen and other structural molecules, which are synthesized and excreted by fibroblasts. MMPs are required for baseline ECM homeostasis, but disruption of MMP regulation due to injury or disease can alter the normal ECM architecture and prevent proper force transmission. Chronic injuries and diseases of muscles and tendons can be severely debilitating, and current therapeutic modalities to enhance healing are quite limited. This review will discuss the mechanobiology of MMPs, and the potential use of MMP inhibitors to improve the treatment of injured and diseased skeletal muscle and tendon tissue.