Are multiple platelet-rich plasma injections useful for treatment of chronic patellar tendinopathy in athletes? a prospective study

Most Publications Regarding Platelet-Rich Plasma Use in the Knee Are From Asia, Investigate Injection for Osteoarthritis, and Show Outcome Improvement: A Scoping Review

PURPOSE

To evaluate and synthesize the available literature related to platelet-rich plasma (PRP) treatment of knee pathologies and to provide recommendations to inform future research in the field.

METHODS

PubMed, CINAHL, and Scopus databases were queried on October 6, 2023. All identified citations were collated and uploaded into Covidence for screening and data extraction. Studies were included if they were human studies published in English with adult cohorts that received PRP as a procedural injection or surgical augmentation for knee pathologies with patient-reported outcome measures (PROMs) and level of evidence Levels I-IV.

RESULTS

Our search yielded 2,615 studies, of which 155 studies from 2006 to 2023 met the inclusion criteria. Median follow-up was 9 months (±11.2 months). Most studies (75.5%) characterized the leukocyte content of PRP, although most studies (86%) did not use a comprehensive classification scheme. In addition, most studies were from Asia (50%) and Europe (32%) and were from a single center (96%). In terms of treatment, 74% of studies examined PRP as a procedural injection, whereas 26% examined PRP as an augmentation. Most studies (68%) examined treatment of knee osteoarthritis. Many studies (83%) documented significant improvements in PROMs, including 93% of Level III/IV evidence studies and 72% of Level I/II evidence studies, although most studies (70%) failed to include minimal clinically important difference values. The visual analog scale was the most-used PROM (58% of studies), whereas the Short Form Health Survey 36-item was the least-used PROM (5% of studies).

CONCLUSIONS

Most published investigations of knee PRP are performed in Asia, investigate procedural injection for osteoarthritis, and show significant outcome improvements. In addition, this review highlights the need for better classification of PRP formulations.

LEVEL OF EVIDENCE

Level IV, scoping Review of level I-IV studies.

Platelet-rich plasma for jumper's knee: a comprehensive review of efficacy, protocols, and future directions

PURPOSE

This comprehensive review evaluates the current state of platelet-rich plasma (PRP) treatment for jumper's knee, also known as patellar tendinopathy. The aim is to assess the efficacy of PRP as a therapeutic option compared to other available procedures, investigate the benefits and potential drawbacks of PRP infiltration, and provide insights into the optimal protocols for PRP preparation and administration.

METHODS

A comprehensive literature search of English articles published up to June 2023 was conducted using PubMed and Scopus databases. Studies evaluating PRP for treating jumper's knee or patellar tendinopathy were analyzed to assess the current state of research in this field.

RESULTS

PRP has demonstrated promising results in promoting cellular remodeling and accelerating the healing process in the jumper's knee. It shows potential benefits in pain reduction, improved function, and accelerated recovery. However, the efficacy of PRP varies depending on patient characteristics, disease severity, and the specific administration methodology. Establishing standardized PRP preparation and administration protocols are necessary to optimize its effectiveness. Further research is needed to define appropriate patient selection criteria and refine the application of PRP therapy in patellar tendinopathy management.

CONCLUSION

Jumper's knee is commonly managed conservatively, but there is a lack of consensus on further treatment options. PRP treatment holds promise in promoting tissue healing and repair. However, standardized protocols for PRP preparation and administration, as well as optimal dosage and number of injections, require further investigation to enhance its efficacy. Continued research efforts are necessary to ascertain the precise role of PRP and its refinement in the management of patellar tendinopathy.

Management of Patellar Tendinopathy

Patellar tendinopathy is a common pathology typically seen in athletes involved in repetitive explosive jumping and running activities. Also known as jumpers' knee, it is commonly seen in high-level basketball players. Typically, athletes continue to play with symptoms, which can be aggravated and progress to partial patellar tendon tears. When partial patellar tendon tears occur, prolonged recovery and decreased performance is commonly seen. The pathology and treatment can be frustrating for both the athlete and medical provider. Patellar tendinopathy typically does not involve inflammation but rather microinjury to the tendon fibers, which leads to mucoid degeneration, necrosis, and loss of transitional fibrocartilage. When partial tendon tears do occur, the typical location is posteromedially adjacent to the patella. Treatment involves a stepwise approach starting with nonoperative means, including activity modification, nonsteroidal anti-inflammatories, and physical therapy focused on eccentrics. Extracorporeal shock wave treatments and injections with platelet-rich plasma or bone marrow aspirate concentrate should be considered, with evolving literature to support their use. Ultrasound percutaneous tendon scrapping with a needle supplemented with the aforementioned injections is an emerging treatment option that the authors have found to be helpful, although further studies are required. Surgical intervention is considered after failure of nonoperative treatments, and typically occurs in tears greater than 50% of the tendon thickness and in tendons with increased thickness (>8.8 mm). Open or arthroscopic debridement can be considered, with no studies showing superior outcomes with either technique; however, no high-quality comparison studies exist. The authors prefer an open technique where, much like a bone-patellar tendon-bone harvest, the unhealthy proximal tendon and bone are excised with then closure of the healthy tendon with absorbable sutures. Suture anchor repair may also be used when necessary. In a recent systematic review, surgical management of patellar tendinopathy has been shown to result in improved patient-reported outcomes with return to sport at high levels.1 Treatment for the difficult and sometimes frustrating pathology of patellar tendinopathy continues to evolve, with biologic and less-invasive ultrasound-based treatments showing promise, and surgical intervention providing reliable outcomes.

Platelet-rich plasma in chronic Achilles tendinopathy

INTRODUCTION

Achilles tendinopathy [AT] is a functional problem characterised by swelling and pain above the Achilles tendon insertion region. In individuals with AT, PRP or platelet-rich plasma can be used as an alternative modality of treatment with an aim to lessen the discomfort and enhance functional recovery. We assessed the available data supporting the effectiveness of PRP in treating chronic AT.

MATERIALS AND METHODS

We did a literature search for randomised controlled trials [RCTs] that contrasted the effectiveness of PRP with that of eccentric exercise and placebo injections as treatment for AT in databases such as the Cochrane Library, Web of Science, PubMed, and EMBASE. The Visual analogue scale [VAS] score, Victorian Institute of Sports Assessment-Achilles [VISA-A] score, and Achilles tendon thickness were used to measure the results. We used the RevMan 5.3.5 software for statistical analysis.

RESULTS

We included five RCTs in this meta-analysis. There was no significant difference in the VISA-A between the PRP and placebo groups at 12 weeks, 24 weeks and 1 year after treatment. However, at 6 weeks after treatment, PRP exhibited better efficacy than the placebo treatment. Two studies in our meta-analysis included VAS scores and tendon thickness. There was no significant difference in VAS scores at 6 weeks and 24 weeks after treatment. However, VAS scores at 12 weeks and tendon thickness were significantly different.

CONCLUSION

PRP injection is an effective treatment for chronic AT. It has a unique potential for increasing function and reducing discomfort in AT patients.

Current Concepts in Patellar Tendinopathy: An Overview of Imaging, Pathogenesis, and Nonoperative and Operative Management

» Approximately 1 in 3 high-impact athletes develops patellar tendinopathy (PT), with the proximal insertion of the patellar tendon being the most commonly affected anatomical site.» Nonoperative treatment options are effective in reducing pain and restoring functionality in most patients with PT. However, operative intervention should be considered when conservative management fails.» A comprehensive review of the literature on surgical procedures, including both open and arthroscopic approaches, was conducted with a specific focus on clinical outcomes and return to sports.» Both open surgery and arthroscopic surgery for PT have demonstrated favorable success rates and return-to-sport outcomes, with arthroscopic treatment potentially expediting the recovery process.

Platelet-rich plasma injection in the treatment of patellar tendinopathy: a systematic review and meta-analysis

Purpose

The objective of the study was to assess the efficacy of autologous platelet-rich plasma (PRP) injections in the treatment of patellar tendinopathy.

Methods

The PubMed, MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials databases were searched for clinical trials which compared PRP injection with other ‘active treatment’ interventions (‘Non-PRP’ injection and ‘No-injection’ treatments) or ‘No-active treatment’ interventions. Randomized and non-randomized clinical trials that had been published up to 15 November 2021, were included in the meta-analysis. The primary outcome, pain relief, was measured on a ‘visual analog scale.’ Secondary outcomes were knee functional activities and quality of life (QoL). The PRISMA guidelines were followed throughout the study.

Results

Eight comparative studies were identified for inclusion in the meta-analysis. Assessment of these studies revealed that there were no significant differences in pain relief, functional outcomes, and QoL in the short, medium, and long term between PRP injection and Non-PRP injection interventions. Similarly, comparison of PRP injection to the No-active treatment intervention showed no differences in short- and medium-term pain relief. However, when PRP injection was compared to the No-injection treatment intervention extracorporeal shock wave therapy (ECWT), the former was found to be more effective in terms of pain relief in the medium term (mean difference [MD] − 1.50; 95% confidence interval [CI] − 2.72 to − 0.28) and long term (MD − 1.70; 95% CI, − 2.90 to − 0.50) and functional outcomes in the medium term (MD 13.0; 95% CI 3.01–22.99) and long term (MD 13.70; 95% CI 4.62–22.78).

Conclusions

In terms of pain relief and functional outcomes, the PRP injection did not provide significantly greater clinical benefit than Non-PRP injections in the treatment of patellar tendinopathy. However, in comparison with ESWT, there was a significant benefit in favor of PRP injection.

Ex vivo study correlating the stiffness of the ovine patellar tendon to age and weight

Tendons play a crucial role in the musculoskeletal system. In humans, tendon injuries, especially chronic tendinopathy, are very common and the patellar tendon is a frequent location for tendinopathy or injuries. The biomechanical characteristics of the patellar tendon, such as elasticity and stiffness, are of paramount importance and constitute major outcome measures in research studies. We aimed to assess whether the stiffness of the healthy ovine patellar tendon changes with age and weight in a population of normal animals. Sixty-eight 'patella-patellar tendon-tibial tuberosity' units from thirty-four Ile-de-France ewes of body mass 65 to 95 kg, euthanized for reasons other than musculoskeletal diseases, underwent a tensile test providing a measure of the tendon stiffness. Animals were sorted into three categories of age (1-2 yo, 3-5 yo, 6-10 yo). We found a positive but not significant correlation between age category and stiffness (r = 0.22, p = 0.27). There was a significantly positive correlation between weight and stiffness (r = 0.39, p = 0.04). In conclusion, the study characterized biomechanical properties of healthy tendons, provided useful reference values, and established the basis for future biomechanical tests on healing tendons in sheep. The most appropriate sheep population for those future studies would be non-overweight young adults presenting with no lameness.

Current Trends in Orthobiologics: An 11-Year Review of the Orthopaedic Literature

BACKGROUND

The use of "orthobiologics" or regenerative therapies in orthopaedic surgery has grown in recent years. Particular interest has been raised with regard to platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells. Although studies have analyzed outcomes after orthobiologic treatment, no study has analyzed how the literature as a whole has evolved.

PURPOSE

To evaluate trends in platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cell publications and to assess how these might inform efforts to establish minimum reporting standards and forecast future use.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A database was compiled systematically using PubMed to identify articles published between 2009 and 2019 within 9 prominent orthopaedic journals and pertaining to the use of platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells in the treatment of musculoskeletal conditions. Included articles were classified as clinical, nonclinical (translational or basic science), or review, and a variety of study parameters were recorded for each. Additional queries were performed to identify articles that utilized minimum reporting standards.

RESULTS

A total of 474 articles (132 clinical, 271 nonclinical, 71 review) were included, consisting of 244 (51.5%) platelet-rich plasma, 146 (30.8%) bone marrow aspirate, 72 (15.2%) adipose-derived cells, and 12 (2.5%) amniotic cells. The greatest annual increase in publications for each orthobiologic topic was from 2018 to 2019. The American Journal of Sports Medicine demonstrated the highest number of overall (34.2%) and clinical (50.0%) publications, and accounted for 44.3% of all platelet-rich plasma publications. The Journal of Orthopaedic Research accounted for the second highest overall number of publications (24.9%) and highest nonclinical publications (41.0%). Platelet-rich plasma accounted for 91.5% of all level 1 clinical studies, while much greater than half of bone marrow aspirate, adipose-derived cells, and amniotic cell publications were level 3 or lower. Out of the 207 articles that used some form of reporting protocol, 59 (28.5%) used an established algorithm and 125 (60.4%) used their own.

CONCLUSION

Interest in orthobiologics continues to grow, as evidenced by an increasing trend in publications over an 11-year period. However, current reporting on orthobiologic formulations is largely heterogeneous, emphasizing the need for minimum reporting standards and higher-quality studies.

Nonoperative and Operative Soft-Tissue and Cartilage Regeneration and Orthopaedic Biologics of the Knee: An Orthoregeneration Network (ON) Foundation Review

Orthoregeneration is defined as a solution for orthopedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and optimally, provide an environment for tissue regeneration. Options include: drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electro-magnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the knee, including symptomatic osteoarthritis and chondral injuries, as well as injuries to tendon, meniscus, and ligament, including the anterior cruciate ligament. Promising and established treatment modalities include hyaluronic acid (HA) in liquid or scaffold form; platelet-rich plasma (PRP); bone marrow aspirate (BMA) comprising mesenchymal stromal cells (MSCs), hematopoietic stem cells, endothelial progenitor cells, and growth factors; connective tissue progenitor cells (CTPs) including adipose-derived mesenchymal stem cells (AD-MSCs) and tendon-derived stem cells (TDSCs); matrix cell-based therapy including autologous chondrocytes or allograft; vitamin D; and fibrin clot. Future investigations should standardize solution preparations, because inconsistent results reported may be due to heterogeneity of HA, PRP, BMAC, or MSC preparations and regimens, which may inhibit meaningful comparison between studies to determine the true efficacy and safety for each treatment.

Biologics in professional and Olympic sport: a scoping review

AIMS

The aim of this study was to prepare a scoping review to investigate the use of biologic therapies in the treatment of musculoskeletal injuries in professional and Olympic athletes.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews and Arksey and O'Malley frameworks were followed. A three-step search strategy identified relevant published primary and secondary studies, as well as grey literature. The identified studies were screened with criteria for inclusion comprising clinical studies evaluating the use of biologic therapies in professional and Olympic athletes, systematic reviews, consensus statements, and conference proceedings. Data were extracted using a standardized tool to form a descriptive analysis and a thematic summary.

RESULTS

A total of 202 studies were initially identified, and 35 met criteria for the scoping review; 33 (94.3%) were published within the last eight years, and 18 (51.4%) originated from the USA. Platelet rich plasma was the most studied biologic therapy, being evaluated in 33 (94.3%) studies. Ulnar collateral ligament and hamstring injuries were the conditions most studied (nine (25.7%) studies and seven (20.0%) studies, respectively). Athletes most frequently participated in baseball, soccer, and American football. Only two (5.7%) studies were level 1 evidence, with interpretation and comparison between studies limited by the variations in the injury profile, biologic preparations, and rehabilitation protocols.

CONCLUSION

There is diverse use of biologic therapies in the management of musculoskeletal injuries in professional and Olympic athletes. There is currently insufficient high-level evidence to support the widespread use of biologic therapies in athletes. Further research priorities include the development of condition/pathology-specific preparations of biologic therapies, and of outcome measures and imaging modalities sufficiently sensitive to detect differences in outcomes, should they exist. Cite this article: Bone Joint J 2021;103-B(7):1189-1196.

The 2020 NBA Orthobiologics Consensus Statement

This 2020 NBA Orthobiologics Consensus Statement provides a concise summary of available literature and practical clinical guidelines for team physicians and players. We recognize that orthobiologic injections are a generally safe treatment modality with a significant potential to reduce pain and expedite early return to play in specific musculoskeletal injuries. The use of orthobiologics in sports medicine to safely reduce time loss and reinjury is of considerable interest, especially as it relates to the potential effect on a professional athlete. While these novel substances have potential to enhance healing and regeneration of injured tissues, there is a lack of robust data to support their regular use at this time. There are no absolutes when considering the implementation of orthobiologics, and unbiased clinical judgment with an emphasis on player safety should always prevail. Current best evidence supports the following: Key Points There is support for the use of leukocyte-poor platelet-rich plasma in the treatment of knee osteoarthritis. There is support for consideration of using leukocyte-rich platelet-rich plasma for patellar tendinopathy. The efficacy of using mesenchymal stromal cell injections in the management of joint and soft tissue injuries remains unproven at this time. There are very few data to suggest that current cell therapy treatments lead to any true functional tissue regeneration. Meticulous and sterile preparation guidelines must be followed to minimize the risk for infection and adverse events if these treatments are pursued.Given the high variability in orthobiologic formulations, team physicians must stay up-to-date with the most recent peer-reviewed literature and orthobiologic preparation protocols for specific injuries.Evidence-based treatment algorithms are necessary to identify the optimal orthobiologic formulations for specific tissues and injuries in athletes.Changes in the regulatory environment and improved standardization are required given the exponential increase in utilization as novel techniques and substances are introduced into clinical practice.

Clinical Evaluations of Intraoperative Injection of Platelet-Rich Plasma in Arthroscopic Single-Row Rotator Cuff Repair at 2-Year Follow-Up

Background. The clinical evidence is conflicted on whether platelet-rich plasma (PRP) therapies have a positive effect on tendon healing and improved functional outcomes. Purpose. To evaluate the potentials of intraoperative injection PRP on the speed and quality of healing in patients undergoing arthroscopic repair for small to medium rotator cuff tears. Methods. A total of 86 patients scheduled for arthroscopic single-row repair of small to medium rotator cuff tears were assigned to undergo either PRP injection (PRP group) or conventional repair (control group). The PRP group ( $N=43$ ) consisted of patients who received an intraoperative injection of liquid PRP. The control group ( $N=43$ ) consisted of patients who did not receive that treatment. The visual analogue scale (VAS) for pain before treatment and at 1, 14 days, 3, 6, and 24 months after surgery were recorded. The clinical outcomes were assessed by the University of California, Los Angeles (UCLA) and Constant scores before treatment and at 3, 6, and 24 months after surgery and magnetic resonance imaging or ultrasound examination at 24 months. Patient satisfaction and retear rate were also assessed. Results. No statistical differences in baseline characteristics such as age, gender, dominant arm, and tear size were observed between the two groups ( $P>0.05$ ). For the PRP group, the mean operation time was 40.22 minutes, and for the control group, the mean operation time was 36.3 minutes. There was a statistically significant difference ( $P=0.036$ ). After surgery, all VAS measurements significantly decreased over time until final follow-up in both groups. No significant difference between the 2 groups was found for any VAS pain measurement at any time point except for the VAS at 1 day postoperatively, which was significantly lower in the PRP group ( $2.39\pm 1.03$ ) than that in the control group ( $3.21\pm 1.85$ ) ( $P=0.014$ ). Analysis of the PRP and control groups demonstrated a statistically significant improvement in UCLA and Constant scores from baseline to the 3-, 6-, and 24-month follow-up assessments ( $P<0.05$ ). However, no significant intergroup differences were observed in the clinical scores between the three follow-up time points ( $P>0.05$ ). At the 24-month follow-up, patient satisfaction rates reached 95.65% and 93.48% for the PRP and control groups, respectively. The retear rate of the PRP group (2/43, 4.65%) was lower than that of the control group (6/43, 13.95%). Conclusions. Although the pain at 1 day after surgery and the retear rate in the PRP group were significantly lower than those in the control group, the liquid PRP injection did not promote better clinical outcomes at the 2-year follow-up.

Biologic therapies for foot and ankle injuries

Introduction: The use of orthobiologics as supplemental treatment for foot and ankle pathologies have increased in the past decades. They have been used to improve the healing of bone and soft tissue injuries. There have been several studies that examined the use of biologics for knee and hip pathologies but the foot and ankle construct has unique features that must be considered.Areas covered: The biologics for foot and ankle injuries that are covered in this review are platelet-rich plasma (PRP), stem cells, growth factors, hyaluronic acid, bone grafts, bone substitutes, and scaffolds. These modalities are used in the treatment of pathologies related to tendon and soft tissue as well as cartilage.Expert opinion: The utilization of biological adjuncts for improved repair and regeneration of ankle injuries represents a promising future in our efforts to address difficult clinical problems. The application of concentrated bone marrow and PRP each represents the most widely studied and commonly used injection therapies with early clinical studies demonstrating promising results, research is also being done using other potential therapies such as stem cells and growth factors; further investigation and outcome data are still needed.

Taping, Bracing, and Injection Treatment for Patellofemoral Pain and Patellar Tendinopathy

PURPOSE OF REVIEW

This article will focus on additional treatment options for the two most common causes of anterior knee pain, patellofemoral pain syndrome, and patellar tendinopathy. Conservative management is the first-line treatment for these conditions. For clinicians to maximize the efficacy of conservative treatment options for their patients, they must understand the most up-to-date literature evaluating the potential benefit of taping, bracing, and injections as adjunctive treatments for maximizing treatment success.

RECENT FINDINGS

Recent studies of bracing and taping have found them to be helpful for patients in the short-term management of pain and improving function. However, less is known about their exact mechanism but studies are encouraging that they have a subtle role in changing patellofemoral biomechanics. Injections remain a commonly used treatment for musculoskeletal conditions; however, the evidence for their use in patellofemoral pain and patellar tendinopathy is limited. The use of platelet-rich plasma (PRP), sclerosing, high volume, or stem cell injections is an exciting new area in the treatment of patellar tendinopathy. However, evidence at this time to recommend these treatments is lacking, and more well-designed studies are needed. The treatment of patellofemoral pain and patellar tendinopathy consists of a multi-faceted approach of physiotherapy and physical modalities. There is evidence for short-term use of taping and bracing for these conditions. The evidence for injections at this time is limited and remains under investigation. Future well-designed randomized controlled studies will provide insight into the efficacy of several different types of injections in the treatment of patellar tendinopathy. Physicians should feel comfortable integrating taping and bracing into their anterior knee pain treatment paradigm while making cautious use of invasive injections as adjunctive therapy.

Percutaneous ultrasonic tenotomy effectively debrides tendons of the extensor mechanism of the knee: A technical note

BACKGROUND

Percutaneous ultrasonic tenotomy (PUT) is a minimally-invasive method of treating patellar tendinosis, but its immediate effect on tendon structure has never been studied. Given the crucial nature of the extensor mechanism of the knee, it is important to understand the procedure's effect on tendon structure prior to clinical implementation. The aim of this study was to analyze the tendon structure of the extensor mechanism of the knee after PUT in a cadaveric model.

METHODS

Four fresh-frozen cadaveric specimens (two patellar and two quadriceps tendons) underwent PUT. The tendons were then sectioned and stained with hematoxilin & eosin (H&E). The sections were analyzed for a clear area of debridement. The area of debridement was calculated as an average of three measurements.

RESULTS

All four tendons demonstrated a clear area of debridement limited to the treatment area without damaging any surrounding tissue. The area of debridement for the patellar and quadriceps tendons treated was 2.89 mm2, 1.5 mm2, 2.98 mm2 and 7.29 mm2, respectively.

CONCLUSIONS

Percutaneous ultrasonic tenotomy effectively debrided the treatment area in all tendons without damaging surrounding tissue. Further work is needed to report clinical outcomes, assess the risk of post-procedure tendon rupture and define return-to-sport progression.

Efficacy of Platelet-rich Plasma for Low Back Pain: A Systematic Review and Meta-analysis

BACKGROUND

 Platelet-rich plasma (PRP) may be beneficial for patients with low back pain. However, the results remain controversial. We conducted a systematic review and meta-analysis to explore the efficacy of PRP for low back pain.

METHODS

 PubMed, Embase, Web of Science, EBSCO, and Cochrane Library databases were searched systematically. Randomized controlled trials (RCTs) assessing the effect of PRP on low back pain were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome was pain scores within 8 weeks. Meta-analysis was performed using the random-effects model.

RESULTS

 Three RCTs involving 131 patients were included in the meta-analysis. Overall, compared with control intervention for low back pain, PRP injection was found to reduce pain scores significantly (mean difference: - 1.47; 95% confidence interval [CI], - 2.12 to - 0.81; p < 0.0001), improve the number of patients with > 50% pain relief at 3 months (risk ratio [RR]: 4.14; 95% CI, 2.22-7.74; p < 0.00001), and offer relatively good patient satisfaction (RR: 1.91; 95% CI, 1.04-3.53; p = 0.04). No increase in adverse events was reported after PRP injection (RR: 1.92; 95% CI, 0.94-3.91; p = 0.07).

CONCLUSIONS

 Compared with control intervention for low back pain, PRP injection was found to improve pain relief and patient satisfaction significantly with no increase in adverse events.

Injection therapies for patellar tendinopathy

Patellar tendinopathy, or jumper's knee is a common musculoskeletal condition characterized by progressive activity-related pain on the anterior aspect of the knee and tenderness on the patellar tendon. A conservative method is often the first choice of treatment, which can include anti-inflammatory medication, injection therapies, physiotherapy, eccentric exercises, extra corporeal shock wave therapy, orthosis, etc. Although there are several treatment options available, the management of patellar tendinopathy is still controversial. The literature reveals many different injection methods are being used by clinicians for the treatment of patellar tendinopathy. Platelet rich plasma, corticosteroids, autologous blood, and aprotinin are the most commonly used injection treatments. Injection therapies give promising results in the management of Patellar tendinopathy. However, due to low quality research and variation in the protocol and population it is difficult to provide a firm conclusion on its effectiveness. More high-quality clinical studies are recommended to determine the effectiveness of injections and at which stage of Patellar tendinopathy they are the most effective. This review can provide insight to clinicians involved in the management of this condition.

Post-Procedure Protocols Following Platelet-Rich Plasma Injections for Tendinopathy: A Systematic Review

OBJECTIVE

Platelet-rich plasma (PRP) has been increasingly studied as a treatment for tendinopathy. Many factors may influence outcomes after PRP, including different protocols following administration. It was hypothesized that there would be heterogeneity in post-PRP protocols.

LITERATURE SURVEY

A systematized review of the literature on post-PRP protocols for tendinopathy was conducted using an electronic search of MEDLINE and Embase databases through September 2018.

METHODOLOGY

After duplicates were removed, English language articles involving adult patients who received PRP for tendinopathy were reviewed. Exclusion criteria included studies with fewer than 10 patients, PRP used to treat pathology other than tendinopathy, multiple protocols in one study, and surgical settings. Protocol specifics were extracted including nonsteroidal anti-inflammatory drugs (NSAID) restrictions before and after injection, postinjection restrictions on movement and weight bearing, use of orthoses, activity modifications, and postinjection rehabilitation protocols. Given limitations in the data, a meta-analysis was not performed.

SYNTHESIS

Eighty-four studies met inclusion criteria. Following PRP injection, weight-bearing restrictions were mentioned rarely (12% of protocols). Orthosis use was uncommon overall (18%) but more common in Achilles tendinopathy protocols (53%). The majority of protocols instituted a period of stretching (51%) and strengthening (54%). Stretching programs generally began 2-7 days following injection, and strengthening programs began within 2-3 weeks. Preinjection NSAID restriction was reported rarely (20%), whereas postinjection NSAID restriction was more common (56%), with a typical restriction of greater than 2 weeks (38%). Return to play or full activity was reported in 42% of protocols, most commonly at 4-6 weeks following injection.

CONCLUSION

Although the clinical effectiveness of PRP remains controversial, even less is known about the effect of post-PRP protocols, which may affect the outcomes attributed to PRP itself. No studies directly compare post-PRP protocols, and the protocols studied demonstrate substantial heterogeneity. Some consensus regarding post-PRP protocols exists, although the rationale for these recommendations is limited.

Platelet Concentrates in Musculoskeletal Medicine

Platelet concentrates (PCs), mostly represented by platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) are autologous biological blood-derived products that may combine plasma/platelet-derived bioactive components, together with fibrin-forming protein able to create a natural three-dimensional scaffold. These types of products are safely used in clinical applications due to the autologous-derived source and the minimally invasive application procedure. In this narrative review, we focus on three main topics concerning the use of platelet concentrate for treating musculoskeletal conditions: (a) the different procedures to prepare PCs, (b) the composition of PCs that is related to the type of methodological procedure adopted and (c) the clinical application in musculoskeletal medicine, efficacy and main limits of the different studies.

Rupture of the Patellar Tendon After Platelet-Rich Plasma Treatment: A Case Report

INTRODUCTION

Rupture of the patellar tendon is becoming more and more frequent, even in sports activities overloading the extensor mechanism of the knee. Platelet-rich plasma (PRP) treatment has been recently introduced in treatment for several knee- and sport-related injuries including muscle strain cartilage defect and tendinopathies. The aim of this case report is to present a case of rupture of the patellar tendon occurred after injections of PRP.

CASE REPORT

A case of a 40-year-old male soccer player sustaining a patellar tendon rupture after a series of 4 PRP injections. At surgery, a complete rupture in the middle of the patellar tendon was found, with severe degenerative changes of the tendon tissue. This case questions the actual efficacy and safety of PRP in severe degenerative tendinopathies.

Platelet-Rich Plasma and Corticosteroid in the Treatment of Rotator Cuff Impingement Syndrome: Randomized Clinical Trial

Objective  This research aims to study the effectiveness of platelet-rich plasma (PRP) in the treatment of patients with rotator cuff impingement syndrome compared with the treatment with subacromial injection of corticosteroids.

Methods  This is a double-blind, randomized, comparative clinical trial. The patients were clinically evaluated with the use of the Disabilities of the Arm, Shoulder and Hand (DASH) outcome measure, University of California Los Angeles (UCLA) shoulder rating scale and Constant-Murley shoulder outcome score (CMS) on the day of application, and then again after 1, 3 and 6 months.

Results  No statistically significant differences were found ( p  < 0.05) when comparing the results of the DASH outcome measure, UCLA shoulder rating scale and CMS of the two groups at baseline and after 1, 3, and 6 months of treatment with subacromial injection. After the treatment, both groups showed a significant improvement in the DASH and UCLA scores ( p  < 0.05) when compared with the baseline. However, the CMS at 6 months after treatment with steroids was lower than the baseline.

Concusions  These findings suggest that PRP is a safe treatment and can be a useful tool in the therapeutic arsenal against of the rotator cuff diseases, for there was no significant difference between the subacromial use of PRP and corticosteroids.

Role of Alpha-2-Microglobulin in the Treatment of Osteoarthritic Knee Pain: a Brief Review of the Literature

PURPOSE OF REVIEW

Chronic knee pain remains a debilitating condition that remains difficult to manage. The purpose of this review, therefore, is to summarize current understanding of alpha-2-microglobulin in the treatment of osteoarthritic knee pain. Furthermore, we investigate its role in the anti-inflammatory properties of platelet-rich plasma (PRP).

RECENT FINDINGS

Alpha-2-microglobulin, a 720-kD protein complex, is an active protease inhibitor with tremendous anti-inflammatory properties in animal models. A growing body of evidence suggests that this complex is the most instrumental factor for cartilage preservation in PRP injections. As an active component of platelet-rich plasma's anti-inflammatory properties, alpha-2-microglobulin has been shown to be an active inhibitor of joint degeneration, cartilage preservation, and improvement in quality of life for patients with knee osteoarthritis compared with a multitude of other modalities.

Platelet-rich plasma injection for the treatment of chronic Achilles tendinopathy: A meta-analysis

BACKGROUND

Platelet-rich plasma (PRP) is used as an alternative therapy to reduce pain and improve functional restoration in patients with Achilles tendinopathy (AT). We evaluated the current evidence for the efficacy of PRP as a treatment for chronic AT.

METHODS

The PubMed, Embase, Web of Science, and The Cochrane Library databases were searched for articles on randomized controlled trials (RCTs) that compared the efficacy of PRP with that of with placebo injections plus eccentric training as treatment for AT. The articles were uploaded over the establishment of the databases to May 01, 2018. The Cochrane risk of bias (ROB) tool was used to assess methodological quality. Outcome measurements included the Victorian Institute of Sports Assessment-Achilles (VISA-A), visual analog scale (VAS) and Achilles tendon thickness. Statistical analysis was performed with RevMan 5.3.5 software.

RESULTS

Five RCTs (n = 189) were included in this meta-analysis. Significant differences in the VISA-A were not observed between the PRP and placebo groups after 12 weeks [standardized mean difference (SMD) = 0.2, 95% confidence interval (95% CI): 0.36 to 0.76, I = 71%], 24 weeks (SMD = 0.77, 95% CI: -0.10-1.65, I = 85%) and 1 year (SMD = 0.83, 95% CI: -0.76-2.42, I = 72%) of treatment. However, PRP exhibited better efficacy than the placebo treatment after 6 weeks (SMD = 0.46, 95% CI: 0.15-0.77, I = 34%). Two studies included VAS scores and tendon thickness. VAS scores after 6 weeks (SMD = 1.35, 95% CI: -0.1.04-3.74, I = 93%) and 24 weeks (SMD = 1.48, 95% CI: -0.1.59-4.55, I = 95%) were not significantly different. However, VAS scores at the 12th week (SMD = 1.10, 95% CI: 0.53-1.68, I = 83%) and tendon thickness (SMD = 1.51, 95% CI: 0.39-2.63, I = 53%) were significantly different.

CONCLUSION

PRP injection around the Achilles tendon is an option for the treatment of chronic AT. Limited evidence supports the conclusion that PRP is not superior to placebo treatment. These results still require verification by a large number of well designed, heterogeneous RCT studies.

Nonsurgical Treatments of Patellar Tendinopathy: Multiple Injections of Platelet-Rich Plasma Are a Suitable Option: A Systematic Review and Meta-analysis

BACKGROUND

Patellar tendinopathy is a condition characterized by anterior knee activity-related pain. It has a high incidence among athletes engaged in jumping sports and may become a chronic condition. Nonoperative management is the first choice in these patients, and several nonsurgical treatment options have been proposed. Nonetheless, clear indications on the most effective approach to address patellar tendinopathy are still lacking.

PURPOSE

To analyze the evidence on nonoperative options to treat chronic patellar tendinopathy through a systematic review of the literature and to perform a meta-analysis to identify the most effective nonsurgical option.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The search was conducted with the PubMed and Cochrane databases on January 4, 2017. All clinical English-language reports of any level of evidence on nonsurgical treatment of patellar tendinopathy were included. The quality of each article was assessed by use of the Coleman score. A meta-analysis was performed on all articles reporting the Victorian Institute of Sport Assessment scale for patellar tendinopathy to evaluate the results of the most described treatments.

RESULTS

A total of 70 studies involving 2530 patients were included in the qualitative data synthesis. The Coleman score showed an overall poor study quality. The most described treatment groups that could be included in the meta-analysis were reported in 22 studies on eccentric exercise, extracorporeal shockwave therapy (ESWT), and platelet-rich plasma (PRP). Single and multiple PRP injections were evaluated separately. Eccentric exercise therapies obtained the best results ( P < .05) at short-term (<6 months, mean 2.7 ± 0.7 months). However, multiple injections of PRP obtained the best results ( P < .05), followed by ESWT and eccentric exercise, at long-term follow-up (≥6 months, mean 15.1 ± 11.3 months).

CONCLUSION

The literature documents several nonsurgical approaches for the treatment of chronic patellar tendinopathy with important limitations in terms of study quality. The available evidence showed an overall positive outcome, but some differences have been highlighted. Eccentric exercises may seem the strategy of choice in the short-term, but multiple PRP injections may offer more satisfactory results at long-term follow-up and can be therefore considered a suitable option for the treatment of patellar tendinopathy.

Quadriceps tendinopathy: a review, part 2-classification, prognosis, and treatment

Overuse injuries of the extensor mechanism of the knee are common in both athletes and non-athletes and usually occur during activities associated with repetitive loading, stress, and knee extension. Numerous reports have been published describing extensor mechanism injuries in athletes, but there is a paucity of studies that focus on quadriceps tendinopathy in the non-athlete population. In addition, there is no universally accepted classification system for tendon pathology. Therefore, we performed a comprehensive literature review of these studies. This review consists of 2 parts. In the previous part we reviewed: (I) epidemiology and (II) diagnosis of quadriceps tendinopathy in the athlete as well as the general population. In this part we discuss: (I) classification; (II) prognosis; and (III) treatment results.

Myths and Facts of In-Office Regenerative Procedures for Tendinopathy

Tendinopathy carries a large burden of musculoskeletal disorders seen in both athletes and aging population. Treatment is often challenging, and progression to chronic tendinopathy is common. Physical therapy, nonsteroidal anti-inflammatory drugs, and corticosteroid injections have been the mainstay of treatment but are not optimal given that most tendon disorders seem to involve degenerative changes in addition to inflammation. The field of regenerative medicine has taken the forefront, and various treatments have been developed and explored including prolotherapy, platelet rich plasma, stem cells, and percutaneous ultrasonic tenotomy. However, high-quality research with standardized protocols and consistent controls for proper evaluation of treatment efficacy is currently needed. This will make it possible to provide recommendations on appropriate treatment options for tendinopathy.

Differing efficacies of autologous platelet-rich plasma treatment in reducing pain following rotator-cuff injury in a single patient

Rotator-cuff tears (RCTs) are typically associated with chronic pain. The most common treatment for reducing pain is the injection of cortisone into the injury site. An alternative and increasingly used technique is the injection of autologous platelet-rich plasma (PRP). A limitation of cortisone is its pain relief is short-lived, while PRP has the limitation of providing pain relief to only about 50% of patients, making its efficacy questioned, although when it is effective, its efficacy is longer than cortisone. Little is known about what accounts for these limitations. This paper presents results from a patient with RCTs causing excruciating pain who received an injection of PRP into that shoulder resulting in complete pain elimination that was ongoing at 2 years and 2 months. When 7-month severe posttrauma pain associated with the RCT developed in the contralateral shoulder, PRP prepared the same way and injected by the same person who performed the first injection provided no pain relief. However, a subsequent single cortisone injection resulted in complete pain elimination, which was ongoing at >15 months. These observations indicate that PRP can have inconsistent effects in reducing pain, not only between patients but also within the same patient. Further, although the pain relief induced by cortisone is normally not long-lasting, when given following a PRP injection, it can induce complete pain relief lasting >15 months. This paper discusses possible reasons for the variability in PRP efficacy on pain relief and addresses the possibility that when administered together, PRP and cortisone may act in a complementary manner, leading to significantly greater and longer-lasting pain relief.

Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part II: treatment options

The treatment of painful chronic tendinopathy is challenging. Multiple non-invasive and tendon-invasive methods are used. When traditional non-invasive treatments fail, the injections of platelet-rich plasma autologous blood or cortisone have become increasingly favored. However, there is little scientific evidence from human studies supporting injection treatment. As the last resort, intra- or peritendinous open or endoscopic surgery are employed even though these also show varying results. This ESSKA basic science committee current concepts review follows the first part on the biology, biomechanics and anatomy of tendinopathies, to provide a comprehensive overview of the latest treatment options for tendinopathy as reported in the literature.

Platelet-rich plasma in tendon-related disorders: results and indications

PURPOSE

Platelet-rich plasma (PRP) is currently the most exploited strategy in the clinical practice to provide a regenerative stimulus for tendon healing. The aim of the present study was to systematically review the available evidence on the treatment of the main tendon disorders where PRP is currently applied.

METHODS

A systematic review of the literature was performed on the use of PRP as a treatment for tendinopathies focusing on the following sites: Achilles tendon, patellar tendon, rotator cuff tendons, and lateral elbow tendons. The following inclusion criteria for relevant articles were used: clinical trials written in English language up to 21 June 2016 on the use of PRP in the conservative or surgical treatment of the aforementioned tendinopathies.

RESULTS

The research identified the following clinical trials dealing with the application of PRP in the selected tendons: 19 papers on patellar tendon (6 being RCTs: 4 dealing with PRP conservative application and 2 surgical), 24 papers on Achilles tendon (4 RCTs: 3 conservative and 1 surgical), 29 on lateral elbow tendons (17 RCTs, all conservative), and 32 on rotator cuff (22 RCTs: 18 surgical and 3 conservative).

CONCLUSION

Patellar tendons seem to benefit from PRP injections, whereas in the Achilles tendon, PRP application is not indicated neither as a conservative approach nor as a surgical augmentation. Lateral elbow tendinopathy showed an improvement in most of the high-level studies, but the lack of proven superiority with respect to the more simple whole-blood injections still questions its use in the clinical practice. With regard to rotator cuff pathology, the vast majority of surgical RCTs documented a lack of beneficial effects, whereas there is still inconclusive evidence concerning its conservative application in rotator cuff disorders.

LEVEL OF EVIDENCE

Systematic review of level I-IV trials, Level IV.

Successful Treatment of Osgood-Schlatter Disease with Autologous-Conditioned Plasma in Two Patients

Osgood–Schlatter Disease (OSD) is a painful, growth-related overuse condition of the tibial tuberosity, leading to inflammation of the patellar ligament at the tibial tuberosity. It primarily affects young adolescents, athletic population, and usually, resolves with age or skeletal maturity. Therapy is usually conservative, with surgery indicated in a minority of cases. For patients with treatment-resistant or refractory OSD, an alternative is the application of autologous platelet concentrate. Here, we describe two cases in which autologous-conditioned plasma therapy was used to treat OSD, and present the treatment protocol developed in our clinic.

The use of platelet-rich plasma to treat chronic tendinopathies: A technical analysis

Platelet-rich plasma (PRP) is blood plasma with a high concentration of autologous platelets which constitute an immense reservoir of growth factors. The clinical use of PRP is widespread in various medical applications. Although highly popular with athletes, the use of PRP for the treatment of tendinopathies remains scientifically controversial, particularly due to the diversity of products that go by the name of "PRP." To optimize its use, it is important to look at the various stages of obtaining PRP. In this literature review, we take a closer look at eight parameters which may influence the quality of PRP: 1) anticoagulants used to preserve the best platelet function, 2) the speed of centrifugation used to extract the platelets, 3) the platelet concentrations obtained, 4) the impact of the concentration of red and while blood cells on PRP actions, 5) platelet activators encouraging platelet degranulation and, hence, the release of growth factors, and 6) the use or nonuse of local anesthetics when carrying out infiltration. In addition to these parameters, it may be interesting to analyze other variables such as 7) the use of ultrasound guidance during the injection with a view to determining the influence they have on potential recovery.

Effect of High-Volume Injection, Platelet-Rich Plasma, and Sham Treatment in Chronic Midportion Achilles Tendinopathy: A Randomized Double-Blinded Prospective Study

BACKGROUND

Injection therapies are often considered alongside exercise for chronic midportion Achilles tendinopathy (AT), although evidence of their efficacy is sparse.

PURPOSE

To determine whether eccentric training in combination with high-volume injection (HVI) or platelet-rich plasma (PRP) injections improves outcomes in AT.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 60 men (age, 18-59 years) with chronic (>3 months) AT were included and followed for 6 months (n = 57). All participants performed eccentric training combined with either (1) one HVI (steroid, saline, and local anesthetic), (2) four PRP injections each 14 days apart, or (3) placebo (a few drops of saline under the skin). Randomization was stratified for age, function, and symptom severity (Victorian Institute of Sports Assessment-Achilles [VISA-A]). Outcomes included function and symptoms (VISA-A), self-reported tendon pain during activity (visual analog pain scale [VAS]), tendon thickness and intratendinous vascularity (ultrasonographic imaging and Doppler signal), and muscle function (heel-rise test). Outcomes were assessed at baseline and at 6, 12, and 24 weeks of follow-up.

RESULTS

VISA-A scores improved in all groups at all time points ( P < .05), with greater improvement in the HVI group (mean ± SEM, 6 weeks = 27 ± 3 points; 12 weeks = 29 ± 4 points) versus PRP (6 weeks = 14 ± 4; 12 weeks = 15 ± 3) and placebo (6 weeks = 10 ± 3; 12 weeks = 11 ± 3) at 6 and 12 weeks ( P < .01) and in the HVI (22 ± 5) and PRP (20 ± 5) groups versus placebo (9 ± 3) at 24 weeks ( P < .01). VAS scores improved in all groups at all time points ( P < .05), with greater decrease in HVI (6 weeks = 49 ± 4 mm; 12 weeks = 45 ± 6 mm; 24 weeks = 34 ± 6 mm) and PRP (6 weeks = 37 ± 7 mm; 12 weeks = 41 ± 7 mm; 24 weeks = 37 ± 6 mm) versus placebo (6 weeks = 23 ± 6 mm; 12 weeks = 30 ± 5 mm; 24 weeks = 18 ± 6 mm) at all time points ( P < .05) and in HVI versus PRP at 6 weeks ( P < .05). Tendon thickness showed a significant decrease only in HVI and PRP groups during the intervention, and this was greater in the HVI versus PRP and placebo groups at 6 and 12 weeks ( P < .05) and in the HVI and PRP groups versus the placebo group at 24 weeks ( P < .05). Muscle function improved in the entire cohort with no difference between the groups.

CONCLUSION

Treatment with HVI or PRP in combination with eccentric training in chronic AT seems more effective in reducing pain, improving activity level, and reducing tendon thickness and intratendinous vascularity than eccentric training alone. HVI may be more effective in improving outcomes of chronic AT than PRP in the short term. Registration: NCT02417987 ( ClinicalTrials.gov identifier).

State-of-the-art ultrasonographic findings in lower extremity sports injuries

Athletes sometimes experience overuse injuries. To diagnose these injuries, ultrasonography is often more useful than plain radiography, computed tomography (CT), or magnetic resonance imaging (MRI). Ultrasonography can show both bone and soft tissue from various angles as needed, providing great detail in many cases. In conditions such as osteochondrosis or enthesopathies such as Osgood-Schlatter disease, Sinding-Larsen-Johansson disease, bipartite patella, osteochondritis dissecans of the knee, painful accessory navicular,and jumper's knee, ultrasonography can reveal certain types of bony irregularities or neovascularization of the surrounding tissue. In patients of enthesopathy, ultrasonography can show the degenerative changes at the insertion of the tendon. Given its usefulness in treatment, ultrasonography is expected to become essential in the management of overuse injuries affecting the lower limb in athletes. J. Med. Invest. 62: 109-113, August, 2015.

Patellar Tendinopathy: Diagnosis and Treatment

Patellar tendinopathy is a common cause of pain in athletes' knees. Historically, it has been related to jumping sports, such as volleyball and basketball. Repetitive jumping generates a considerable load of energy in the extensor mechanism, leading to symptoms. The main pathophysiologic phenomenon in patellar tendinopathy is tendinosis, which is a degenerative disorder rather than an inflammatory disorder; therefore, the other popular term for this disease, tendinitis, is not appropriate. The nonsurgical treatment of patellar tendinopathy is focused on eccentric exercises and often has good results. Other experimental options, with variable levels of evidence, are available for recalcitrant cases. Surgical treatment is indicated for cases that are refractory to nonsurgical treatment. Open or arthroscopic surgery can be performed; the two methods are comparable, but arthroscopic surgery results in a faster recovery time.