One-year follow-up of platelet-rich plasma treatment in chronic Achilles tendinopathy: a double-blind randomized placebo-controlled trial

Is Platelet-rich Plasma Injection Effective for Chronic Achilles Tendinopathy? A Meta-analysis

BACKGROUND

Chronic Achilles tendinopathy is common in the general population, and platelet-rich plasma (PRP) is seeing increased use to treat this problem. However, studies disagree as to whether PRP confers a beneficial effect for chronic Achilles tendinopathy, and no one to our knowledge has pooled the available randomized trials in a formal meta-analysis to try to reconcile those differences.

QUESTIONS/PURPOSES

In the setting of a systematic review and meta-analysis of randomized controlled trials (RCTs), we asked: Does PRP plus eccentric strength training result in (1) greater improvements in Victorian Institute of Sports Assessment-Achilles (VISA-A) scores; (2) differences in tendon thickness; or (3) differences in color Doppler activity compared with placebo (saline) injections plus eccentric strength training in patients with chronic Achilles tendinopathy?

METHODS

A search of peer-reviewed articles was conducted to identify all RCTs using PRP injection with eccentric training for chronic Achilles tendinopathy in the electronic databases of PubMed, Web of Science (SCI-E/SSCI/A&HCI), and EMBASE from January 1981 to August 2017. Results were limited to human RCTs and published in all languages. Two reviewers assessed study quality using the Cochrane Collaboration risk-of-bias tool. All the included studies had low risk of bias. The primary endpoint was improvement in the VISA-A score, which ranges from 0 to 100 points, with higher scores representing increased activity and less pain; we considered the minimum clinically important difference on the VISA-A to be 12 points. Secondary outcomes were tendon thickness change (with a thicker tendon representing more severe disease), color Doppler activity (with more activity representing a poorer result), and other functional measures (such as pain and return to sports activity). Four RCTs involving 170 participants were eligible and included 85 participants treated with PRP injection and eccentric training and 85 treated with saline injection and eccentric training. The patients in both PRP and placebo (saline) groups seemed comparable at baseline. We assessed for publication bias using a funnel plot and saw no evidence of publication bias. Based on previous studies, we had 80% power to detect a 12-point difference on the VISA-A score with the available sample size in each group.

RESULTS

With the numbers available, there was no difference between the PRP and saline groups regarding the primary outcome (VISA-A score: mean difference [MD], 5.3; 95% confidence interval [CI], -0.7 to 11.3; p = 0.085). Likewise, we found no difference between the PRP and saline groups in terms of our secondary outcomes of tendon thickness change (MD, 0.2 mm; 95% CI, 0.6-1.0 mm; p = 0.663) and color Doppler activity (MD, 0.1; 95% CI, -0.7 to 0.4; p = 0.695).

CONCLUSIONS

PRP injection with eccentric training did not improve VISA-A scores, reduce tendon thickness, or reduce color Doppler activity in patients with chronic Achilles tendinopathy compared with saline injection. Larger randomized trials are needed to confirm these results, but until or unless a clear benefit has been demonstrated in favor of the new treatment, we cannot recommend it for general use.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Effects of mesenchymal stromal cells versus serum on tendon healing in a controlled experimental trial in an equine model

BACKGROUND

Mesenchymal stromal cells (MSC) have shown promising results in the treatment of tendinopathy in equine medicine, making this therapeutic approach seem favorable for translation to human medicine. Having demonstrated that MSC engraft within the tendon lesions after local injection in an equine model, we hypothesized that they would improve tendon healing superior to serum injection alone.

METHODS

Quadrilateral tendon lesions were induced in six horses by mechanical tissue disruption combined with collagenase application 3 weeks before treatment. Adipose-derived MSC suspended in serum or serum alone were then injected intralesionally. Clinical examinations, ultrasound and magnetic resonance imaging were performed over 24 weeks. Tendon biopsies for histological assessment were taken from the hindlimbs 3 weeks after treatment. Horses were sacrificed after 24 weeks and forelimb tendons were subjected to macroscopic and histological examination as well as analysis of musculoskeletal marker expression.

RESULTS

Tendons injected with MSC showed a transient increase in inflammation and lesion size, as indicated by clinical and imaging parameters between week 3 and 6 (p < 0.05). Thereafter, symptoms decreased in both groups and, except that in MSC-treated tendons, mean lesion signal intensity as seen in T2w magnetic resonance imaging and cellularity as seen in the histology (p < 0.05) were lower, no major differences could be found at week 24.

CONCLUSIONS

These data suggest that MSC have influenced the inflammatory reaction in a way not described in tendinopathy studies before. However, at the endpoint of the current study, 24 weeks after treatment, no distinct improvement was observed in MSC-treated tendons compared to the serum-injected controls. Future studies are necessary to elucidate whether and under which conditions MSC are beneficial for tendon healing before translation into human medicine.

Platelet-rich plasma does not reduce skeletal muscle fibrosis after distraction osteogenesis

Background

Skeletal muscle fibrosis caused by an increase in collagen deposition often occurs after distraction osteogenesis. Although studies are available reporting the effects of platelet-rich plasma (PRP) on tissue healing following injury, current findings remain controversial. This study focused on determining whether PRP reduces skeletal muscle fibrosis caused by distraction osteogenesis.

Methods

Tibial osteotomies were performed on 8-week-old wild type mice, and tibiae were distracted at a rate of 0.42 mm/day for 2 weeks, starting 1 week after osteotomy. Immediately after distraction was completed (3 weeks after osteotomy), PRP or phosphate buffered saline (as a sham) was injected into the gastrocnemius (GC) muscle. The GC muscles were harvested and analyzed.

Results

The amount and area of collagenous tissue increased in both the PRP and control groups following distraction osteogenesis, but the changes were not significantly different between both groups at all time points (p = 0.89, 0.45, 0.33 and 0.52 at 4, 6, 8 and 10 weeks).

Conclusion

From this study, our results suggest that PRP did not significantly reduce skeletal muscle fibrosis due to distraction osteogenesis.

Ultrasound elastography and ultrasound tissue characterisation for tendon evaluation

Ultrasound elastography (UE) and ultrasound tissue characterisation (UTC) are two newer modes of ultrasound (US) which have begun to attract scientific interests as ways to improve tendon characterisation. These modes of US show early promise in improved diagnostic accuracy, prediction of at-risk tendons and prognostication capability beyond conventional grey-scale US. Here, we provide a review of the literature on UE and UTC for Achilles, patellar and rotator cuff tendons.

The translational potential of this article: The present literature indicates that UE and UTC could potentially increase the clinician's ability to accurately diagnose the extent of tendon pathology, including preclinical injury.

No beneficial effect of Polidocanol treatment in Achilles tendinopathy: a randomised controlled trial

PURPOSE

Polidocanol injections have been used to treat chronic Achilles tendinopathy in clinical settings, but the few studies published show inconsistent results. The aim of this study was to evaluate the mid-term effect of Polidocanol in patients with chronic Achilles tendinopathy. It was hypothesised that patients treated with Polidocanol would have significant improvements in the outcome measures investigated compared to patients treated with a placebo treatment at mid-term follow-up.

METHODS

This randomised controlled trial included forty-eight patients aged 32-77 years with a history of Achilles tendinopathy for at least 3 months and with neovascularisation demonstrated by ultrasonography was included. A minimum of 3 months of eccentric exercise treatment was required before participating. The patients were allocated to a maximum of two injection of either Polidocanol or Lidocaine (placebo). The primary outcome measure was pain during walking reported on a visual analogue scale. Secondary outcome measures were Foot and Ankle Outcome Score (FAOS), patient satisfaction with treatment and, shortly after inclusion, the Victorian Institute of Sports Assessment-Achilles questionnaire (VISA-A) was also included. Follow-up examinations were performed after 3 and 6 months.

RESULTS

Pain during walking decreased during the 6-month follow-up period, but no significant differences were seen between the two groups. The same tendency was seen for FAOS and VISA-A in which both groups showed an improvement at 3- and 6-month follow-up, but no mid-term differences between the groups were seen. An equal number of patients in the two groups were satisfied with the treatment at follow-up.

CONCLUSIONS

The results indicate that Polidocanol is a safe treatment, but the mid-term effects are the same as a placebo treatment. This further questions the use of Polidocanol in the treatment of chronic Achilles tendinopathy.

LEVEL OF EVIDENCE

I.

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.

The Efficacy of Platelet-Rich Plasma on Tendon and Ligament Healing: A Systematic Review and Meta-analysis With Bias Assessment

BACKGROUND

There has been a surge in high-level studies investigating platelet-rich plasma (PRP) for tendon and ligament injuries. A number of meta-analyses have been published, but few studies have focused exclusively on tendon and ligament injuries.

PURPOSE

To perform a meta-analysis assessing the ability of PRP to reduce pain in patients with tendon and ligament injuries.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

This study followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A comprehensive search of the literature was carried out in April 2017 using electronic databases PubMed, MEDLINE, and the Cochrane Library. Only level 1 studies were included. Platelet and leukocyte count, injection volume, kit used, participant age/sex, comparator, and activating agent used were recorded. The short-term and long-term efficacy of PRP was assessed using the visual analog scale (VAS) to measure pain intensity. Injury subgroups (rotator cuff, tendinopathy, anterior cruciate ligament, and lateral epicondylitis) were evaluated. Funnel plots and the Egger test were used to screen for publication bias, and sensitivity analysis was performed to evaluate the effect of potential outliers by removing studies one at a time.

RESULTS

Thirty-seven articles were included in this review, 21 (1031 participants) of which could be included in the quantitative analysis. The majority of studies published investigated rotator cuff injuries (38.1%) or lateral epicondylitis (38.1%). Seventeen studies (844 participants) reported short-term VAS data, and 14 studies (771 participants) reported long-term VAS data. Overall, long-term follow-up results showed significantly less pain in the PRP group compared with the control group (weighted mean difference [WMD], -0.84; 95% CI, -1.23 to -0.44; P < .01). Patients treated with PRP for rotator cuff injuries (WMD, -0.53; 95% CI, -0.98 to -0.09; P = .02) and lateral epicondylitis (WMD, -1.39; 95% CI, -2.49 to -0.29; P = .01) reported significantly less pain in the long term. Substantial heterogeneity was reported at baseline ( I² = 72.0%; P < .01), short-term follow-up ( I² = 72.5%; P < .01), long-term follow-up ( I² = 76.1%; P < .01), and overall ( I² = 75.8%; P < .01). The funnel plot appeared to be asymmetric, with some missingness at the lower right portion of the plot suggesting possible publication bias.

CONCLUSION

This review shows that PRP may reduce pain associated with lateral epicondylitis and rotator cuff injuries.

Bone marrow mesenchymal stem cells do not enhance intra-synovial tendon healing despite engraftment and homing to niches within the synovium

Background

Intra-synovial tendon injuries display poor healing, which often results in reduced functionality and pain. A lack of effective therapeutic options has led to experimental approaches to augment natural tendon repair with autologous mesenchymal stem cells (MSCs) although the effects of the intra-synovial environment on the distribution, engraftment and functionality of implanted MSCs is not known. This study utilised a novel sheep model which, although in an anatomically different location, more accurately mimics the mechanical and synovial environment of the human rotator cuff, to determine the effects of intra-synovial implantation of MSCs.

Methods

A lesion was made in the lateral border of the lateral branch of the ovine deep digital flexor tendon within the digital sheath and 2 weeks later 5 million autologous bone marrow MSCs were injected under ultrasound guidance into the digital sheath. Tendons were recovered post mortem at 1 day, and 1–2, 4, 12 and 24 weeks after MSC injection. For the 1-day and 1–2-week groups, MSCs labelled with fluorescent-conjugated magnetic iron-oxide nanoparticles (MIONs) were tracked with MRI, histology and flow cytometry. The 4, 12 and 24-week groups were implanted with non-labelled cells and compared with saline-injected controls for healing.

Results

The MSCs displayed no reduced viability in vitro to an uptake of 20.0 ± 4.6 pg MIONs per cell, which was detectable by MRI at minimal density of ~ 3 × 10⁴ cells. Treated limbs indicated cellular distribution throughout the tendon synovial sheath but restricted to the synovial tissues, with no MSCs detected in the tendon or surgical lesion.

The lesion was associated with negligible morbidity with minimal inflammation post surgery. Evaluation of both treated and control lesions showed no evidence of healing of the lesion at 4, 12 and 24 weeks on gross and histological examination.

Conclusions

Unlike other laboratory animal models of tendon injury, this novel model mimics the failed tendon healing seen clinically intra-synovially. Importantly, however, implanted stem cells exhibited homing to synovium niches where they survived for at least 14 days. This phenomenon could be utilised in the development of novel physical or biological approaches to enhance localisation of cells in augmenting intra-synovial tendon repair.

Meta-analysis Comparing Autologous Blood-Derived Products (Including Platelet-Rich Plasma) Injection Versus Placebo in Patients With Achilles Tendinopathy

PURPOSE

To compare the effectiveness of autologous blood-derived products (ABP) injection with that of placebo (sham injection, no injection, or physiotherapy alone) in patients with Achilles tendinopathy.

METHODS

Electronic databases, including PubMed, Scopus, EMBASE, and Cochrane Library were searched up to June 2017. All published or unpublished randomized controlled trials (RCTs) were included. Two independent raters assessed the risk of bias of RCTs with the Cochrane Risk of Bias Tool. The primary outcome was Victorian Institute of Sports Assessment-Achilles (VISA-A) score. Weighted mean differences (WMDs) were used for random effect meta-analysis.

RESULTS

Seven RCTs were enrolled in meta-analysis. The ABP injection and placebo revealed equal effectiveness in VISA-A score improvement at 4 to 6 weeks (short term, WMD 2.29, 95% confidence interval [CI]: -1.69, 6.27), 12 weeks (medium term, WMD 2.63, 95% CI: -1.72, 6.98), 24 weeks (long term, WMD 4.61, 95% CI: -1.25, 10.47), and 48 weeks (very long term, WMD 4.16, 95% CI: -6.82, 15.14). In meta-regression, there was no association between change in VISA-A score and duration of symptoms at 4 to 6 weeks (short term), 12 weeks (medium term), and 24 weeks (long term).

CONCLUSIONS

This meta-analysis revealed that ABP injection was not more effective than placebo (sham injection, no injection, or physiotherapy alone) in Achilles tendinopathy and that no association was found between therapeutic effects and duration of symptoms.

LEVEL OF EVIDENCE

Level I, meta-analysis of Level I studies.

Achilles Pain, Stiffness, and Muscle Power Deficits: Midportion Achilles Tendinopathy Revision 2018

The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The purpose of these revised clinical practice guidelines is to review recent peer-reviewed literature and make recommendations related to midportion Achilles tendinopathy. J Orthop Sports Phys Ther 2018;48(5):A1-A38. doi:10.2519/jospt.2018.0302.

The role of rehabilitation after regenerative and orthobiologic procedures for the treatment of tendinopathy: a systematic review

Aim: Significant variability exists in the literature, with no clear consensus to the optimal protocol after a regenerative procedure. Given this uncertainty, the authors systematically reviewed the literature cataloging the different variables that may influence outcomes. Methods: Search was limited to randomized clinical trials and prospective cohort studies of regenerative procedures for the treatment of tendinopathy. Variables were predetermined, and included: cyrotherapy, pre- and post-procedure nonsteroidal anti-inflammatory drugs use, recommendations for alternative pain medications, immobilization and duration of rest. Variables were categorized based on the influence of the intervention on the three phases of healing. Results: 749 studies were assessed for eligibility, and 60 studies were included. Significant variability existed in the literature. Conclusion: Despite the importance of rehabilitation after regenerative procedures, there is a paucity of evidence available to guide clinicians and highlights the need for additional validation.

Editorial Commentary: The Amsterdam Achilles Tendinopathy Endoscopic Treatment: Should We Start Booking Our Patients for Surgery?

Mid-portion Achilles tendinopathy remains an elusive clinical and pathologic condition, with only a limited treatment algorithm to guide us. Although the risk factors and natural history have been documented, the exact etiology and source of pain generation remains unclear in the literature. Several Level I studies have shown reasonable success with a myriad of nonoperative treatments over the long term. Surgery is often reserved as the last resort for those who have failed nonoperative treatment, with mixed techniques and results. The endoscopic surgery literature for this condition is lacking, and more studies are needed to clarify the proper indications, techniques, and results of this disabling problem.

Noninsertional Tendinopathy of the Achilles

Noninsertional Achilles tendinosis is differentiated from insertional Achilles tendinosis based on anatomic location. Tendinosis, as opposed to tendonitis, is primarily a degenerative process and the role of inflammation is believed limited. The etiology of Achilles tendinopathy may include overuse leading to repetitive microtrauma, poor vascularity of the tissue, mechanical imbalances of the extremity, or combination of these elements. There is evidence to support eccentric exercise nonoperative management for patients with noninsertional Achilles tendinopathy. Operative treatment options include percutaneous longitudinal tenotomies, minimally invasive tendon scraping, open débridement and tubularization, and tendon augmentation with flexor hallucis longus.

Efficacy of platelet-rich plasma injections for symptomatic tendinopathy: systematic review and meta-analysis of randomised injection-controlled trials

Aim

To determine the efficacy of platelet-rich plasma (PRP) injections for symptomatic tendinopathy.

Design

Systematic review of randomised, injection-controlled trials with meta-analysis.

Data sources

Systematic searches of MEDLINE and EMBASE, supplemented by manual searches.

Eligibility criteria for selecting studies

Randomised controlled trials with 3 months minimum follow-up that evaluated pain reduction with PRP versus control (saline, local anaesthetic, corticosteroid) injections in patients with symptomatic tendinopathy.

Results

A total of 16 randomised controlled trials (18 groups) of PRP versus control were included. Median sample size was 35 patients, a study size that would require an effect size ≥1.0 to achieve statistical significance. PRP was more efficacious than control in reducing tendinopathy pain, with an effect size of 0.47 (95% CI 0.22 to 0.72, p<0.001), signifying a moderate treatment effect. Heterogeneity among studies was moderate (I²=67%, p<0.001). In subgroup analysis and meta-regression, studies with a higher proportion of female patients were associated with greater treatment benefits with PRP.

Conclusions

Injection of PRP is more efficacious than control injections in patients with symptomatic tendinopathy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Magnetic resonance and ultrasound in achilles tendinopathy: Predictive role and response assessment to platelet-rich plasma and adipose-derived stromal vascular fraction injection

OBJECTIVE

To assess the correlation between magnetic resonance and ultrasound findings and clinical outcome after intratendinous injection of leucocyte-rich platelet-rich plasma or adipose-derived stromal vascular fraction in patients with non-insertional Achilles tendinopathy.

MATERIALS AND METHODS

Forty-three patients (age: 47.8±5.1, range 29-55) with unilateral or bilateral non-insertional Achilles tendinopathy (58 tendons overall) were randomly assigned to platelet-rich plasma (22 patients, 28 tendons) or adipose-derived stromal vascular fraction (21 patients, 30 tendons) injection group. All patients underwent magnetic resonance (tendon cross-sectional area, signal intensity, maximum anteroposterior thickness were measured), ultrasound (maximum anteroposterior thickness, power Doppler signal, ultrasound gray scale echotexture were measured), and visual analogue scale (VAS) pain evaluation at baseline and at six months from treatment. Wilcoxon, intraclass correlation coefficient, repeated measure ANOVA tests were used.

RESULTS

There was a significant (P<0.001) decrease of mean VAS from pre-treatment (6.4±1.4) to six-month evaluation (1.8±1.7). Significant increase of tendon thickness measured using magnetic resonance (P=0.013) and ultrasound (P=0.012) and power Doppler signal (P=0.027) was seen. There was no significant difference between pre- and post-treatment cross sectional area, signal intensity, and echotexture (P>0.217). None of the pre-treatment parameters was a predictor of treatment outcome (P>0.104). There was an excellent agreement between tendon thickness measurement between magnetic resonance and ultrasound (intraclass correlation coefficient=0.986) CONCLUSIONS: Both treatments seem to allow for clinical benefit, associated to early slight increase of tendon size and power Doppler signal. Imaging cannot be used as a predictor of clinical outcome.

Implicit hype? Representations of platelet rich plasma in the news media

Platelet Rich Plasma (PRP) has gained popularity in recent years for treating sports-related injuries and the news media frequently reports on elite athletes’ and celebrities’ use of PRP. We conducted a content analysis of newspaper coverage of PRP in Australia, Canada, Ireland, New Zealand, United Kingdom, and the United States. Findings show that news media coverage of PRP appears most frequently in sports-related stories, and in relation to elite athletes use of PRP. PRP injections are largely portrayed as a routine treatment for sports-related injuries and newspaper articles rarely discuss the limitations or efficacy of PRP. We argue that while news media coverage of PRP exhibits very few common hallmarks of hype, its portrayal as a routine treatment used by elite athletes and celebrities creates an implicit hype. This implicit hype can contribute to public misunderstandings of the efficacy of PRP.

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.

Analysis of cytokine profile and growth factors in platelet-rich plasma obtained by open systems and commercial columns

Objective:

To evaluate growth factors and cytokines in samples of platelet-rich plasma obtained by three different centrifugation methods.

Methods:

Peripheral blood of six individuals with no hematological diseases, aged 18 to 68 years, was drawn to obtain platelet-rich plasma, using the open method and commercial columns by Medtronic and Biomet. The products obtained with the different types of centrifugation were submitted to laboratory analysis, including pro-inflammatory cytokines and chemokines by flow cytometry assays, the concentration of fibroblast growth factors-2 (FGF-2) and transforming growth factor-beta1 (TGF-β1).

Results:

The diverse separation methods generated systematically different profiles regarding number of platelets and leukocytes. The Medtronic system yielded a product with the highest concentration of platelets, and the open method, with the lowest concentration of platelets. The results of cytokine analysis showed that the different types of centrifugation yielded products with high concentrations of interleukin 8, interleukin 1β. The open system resulted in a product with high levels of interleukin 6. Other cytokines and chemokines measured were similar between systems. The product obtained with the open method showed higher levels of TGF-β1 in relation to other systems and low FGF-2 levels.

Conclusion:

The formed elements, growth factors and cytokines in samples of platelet-rich plasma varied according to the centrifugation technique used.

Objetivo:

Avaliar fatores de crescimento e citocinas em amostras de plasma rico em plaquetas obtidas por três diferentes métodos de centrifugação.

Métodos:

Foi coletado sangue periférico de seis indivíduos, sem doença hematológica, com idades entre 18 e 68 anos, para obtenção de plasma rico em plaquetas, utilizando o método aberto e sistemas comerciais das empresas Medtronic e Biomet. Os produtos obtidos com os diferentes tipos de centrifugação foram submetidos às análises laboratoriais, incluindo citocinas próinflamatórias e quimiocinas, por meio de ensaios de citometria de fluxo, concentração do fator de crescimento fibroblástico-2 (FGF-2) e fator de crescimento transformador-beta1 (TGF-β1).

Resultados:

As diferentes centrifugações geraram perfis sistematicamente diferentes referentes ao número de plaquetas e de leucócitos. O sistema da Medtronic originou produto com a maior concentração de plaquetas, e o método aberto com a menor concentração de plaquetas. Os resultados da análise de citocinas demonstraram que os diferentes tipos de centrifugação originaram produtos com elevadas concentrações de interleucina 8 e interleucina 1β. O sistema aberto resultou em produto com elevados níveis de interleucina 6. As demais citocinas e quimiocinas mensuradas foram similares entre os sistemas. O produto obtido com o método aberto apresentou níveis superiores de TGF-β1 em relação aos demais sistemas e reduzidos níveis de FGF-2.

Conclusão:

Os elementos figurados, fatores de crescimento e citocinas, em amostras de plasma rico em plaquetas, variaram conforme a técnica de centrifugação utilizada.

Intratendon Delivery of Leukocyte-Poor Platelet-Rich Plasma Improves Healing Compared With Leukocyte-Rich Platelet-Rich Plasma in a Rabbit Achilles Tendinopathy Model

BACKGROUND

Chronic tendinopathy is a commonly occurring clinical problem that affects both athletes and inactive middle-aged patients. Although some studies have shown that different platelet-rich plasma (PRP) preparations could exert various therapeutic effects in vitro, the role of leukocytes in PRP has not yet been defined under tendinopathy conditions in vivo.

PURPOSE

This study compared the effects of the intratendon delivery of leukocyte-poor PRP (Lp-PRP) versus leukocyte-rich PRP (Lr-PRP) in a rabbit chronic tendinopathy model in vivo.

STUDY DESIGN

Controlled laboratory study.

METHODS

Four weeks after a local injection of collagenase in the Achilles tendon, the following treatments were randomly administered on the lesions: injections of (1) 200 μL of Lp-PRP (n = 8), (2) 200 μL of Lr-PRP (n = 8), or (3) 200 μL of saline (n = 8). Healing outcomes were assessed at 4 weeks after therapy with magnetic resonance imaging (MRI), cytokine quantification, real-time polymerase chain reaction analysis of gene expression, histology, and transmission electron microscopy (TEM).

RESULTS

MRI revealed that the Lr-PRP and saline groups displayed higher signal intensities compared with the Lp-PRP group with T2 mapping. Histologically, the Lp-PRP group displayed significantly better general scores compared with the Lr-PRP ( P = .001) and saline ( P < .001) groups. Additionally, TEM showed that the Lp-PRP group had larger collagen fibril diameters than the Lr-PRP group ( P < .001). Enzyme-linked immunosorbent assay showed a significantly lower level of catabolic cytokine IL-6 in the Lp-PRP group compared with the Lr-PRP ( P = .001) and saline ( P = .021) groups. The Lp-PRP group displayed significantly increased expression of collagen I compared with the saline group ( P = .004) but not the Lr-PRP group. Both the Lp-PRP and Lr-PRP groups exhibited significantly lower matrix metalloproteinase (MMP)-1 and MMP-3 expression levels compared with the saline group. However, only the Lp-PRP group displayed significantly higher expression of TIMP-1 than the saline group ( P = .024).

CONCLUSION

Compared with Lr-PRP, Lp-PRP improves tendon healing and is a preferable option for the clinical treatment of tendinopathy.

CLINICAL RELEVANCE

PRP is widely used in the clinical management of chronic tendinopathy. However, the clinical results are ambiguous. It is imperative to understand the influence of leukocytes on PRP-mediated tissue healing in vivo, which could facilitate the better clinical management of chronic tendinopathy. Further studies are needed to translate our findings to the clinical setting.

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).

Study protocol: a double blind randomised control trial of high volume image guided injections in Achilles and patellar tendinopathy in a young active population

Background

Chronic tendinopathy is a significant problem particularly in active populations limiting sporting and occupational performance. The prevalence of patellar tendinopathy in some sports is near 50% and the incidence of lower limb tendinopathy is 1.4% p.a. in the UK Military. Management includes isometric, eccentric, heavy slow resistance exercises and extracorporeal shockwave therapy (ESWT). Often these treatments are inadequate yet there is no good evidence for injection therapies and success rates from surgery can be as low as 50%.

High Volume Image Guided Injection (HVIGI) proposes to strip away the neovascularity and disrupt the nerve ingrowth seen in chronic cases and has shown promising results in case series. This study aims to investigate the efficacy of HVIGI in a randomised controlled trial (RCT).

Methods

RCT comparing 40ml HVIGI, with or without corticosteroid, with a 3ml local anaesthetic sham-control injection. Ninety-six participants will be recruited. Inclusion criteria: male, 18–55 years old, chronic Achilles or patellar tendinopathy of at least 6 months, failed conservative management including ESWT, and Ultrasound (US) evidence of neovascularisation, tendon thickening and echogenic changes. Outcome measures will be recorded at baseline, 6 weeks, 3, 6 and 12 months. Primary outcome measures include The Victoria Institute of Sport Assessments for Achilles and patellar tendinopathy (VISA-A and VISA-P) and VAS pain. Secondary outcome measures include Modified Ohberg score, maximum tendon diameter and assessment of hypoechoic appearance on US, and Functional Activity Assessment.

Discussion

Despite previous interventional trials and reviews there is still insufficient evidence to guide injectable therapy for chronic tendinopathy that has failed conservative treatment. The scant evidence available suggests HVIGI has the greatest potential however there is no level one RCT evidence to support this. Investigating the efficacy of HVIGI against control in a RCT and separating the effect of HVIGI and corticosteroid will add high level evidence to the management of chronic tendinopathy resistant to conservative treatment.

Trial Registration

EudraCT: 2015-003587-36 3 Dec 2015

Midsubstance Tendinopathy, Surgical Management

Noninsertional Achilles tendinopathy often responds to nonoperative treatment. When nonoperative treatment fails, the clinician must distinguish between paratendinopathy and noninsertional tendinopathy. In paratendinopathy, myofibroblasts synthesize collagen, causing adhesions, and the paratenon may be released or excised. If a core area of tendinopathy is identified on MRI, the area is excised longitudinally and repaired with a side-to-side suture. If greater than 50% of the tendon diameter is excised, the authors recommend a short flexor hallucis longus tendon transfer with an interference screw. A turndown flap of the gastrocnemius aponeurosis is also described with good results.

Percutaneous planter fasciitis release under local anesthesia: A prospective study

PURPOSE

Plantar fasciitis is the most common cause of pain on the bottom of the heel. It occurs when the strong band of the tissue supporting the arch of foot becomes irritated and inflamed. The majority of patients can be treated conservatively but some resistant cases need surgery eventually. This study aims to evaluate the outcome results of percutaneous planter fascia release under local anesthesia for chronic planter fasciitis.

METHODS

This prospective study was conducted in the Department of Orthopaedic Surgery in the School of Medical Science and Research, Sharda University, India from December 2010 to December 2013. Totally 78 patients with planter fasciitis for more than 6-12 months were recruited from the outpatient department. All patients were operated on under local anesthesia and followed up for a year.

RESULTS

The clinical results were evaluated in terms of pain, activity level and patient satisfaction. Pain relief was achieved averagely at eight weeks after surgery. The results were excellent in 88.46% (69/78) patients and good in 6.41% (9/78) patients. Neither complications of lateral column instability, sinus tarsitis and metatarsalgia nor wound-related complications were encountered. On subjective evaluations, 88.46% (69/78) patients reported full satisfaction and 6.41% (9/78) reported partial satisfaction after treatment.

CONCLUSION

Percutaneous planter fasciitis release under local anesthesia is a minimally invasive procedure that can be performed in the outpatient setting. It is easy, quick, effective and moreover with few complications.

Midsubstance Tendinopathy, Percutaneous Techniques (Platelet-Rich Plasma, Extracorporeal Shock Wave Therapy, Prolotherapy, Radiofrequency Ablation)

The focus of this article is to present the current options available for noninvasive and percutaneous treatment options for noninsertional Achilles tendinopathy. An attempt is made to offer recommendations for both the treatment techniques as well as postprocedure protocols to be considered. Additionally, because there are numerous treatment options in this category, the different techniques are summarized in a chart format with a short list of pros and cons as well as the levels of evidence in the literature to support the different modalities.

Non-insertional Achilles tendinopathy

Non-insertional Achilles tendinopathy is a degenerative condition characterised by pain on activity.Eccentric stretching is the most effective treatment.Surgical treatment is reserved for recalcitrant cases.Minimally-invasive and tendinoscopic treatments are showing promising results. Cite this article: Pearce CJ, Tan A. Non-insertional Achilles tendinopathy. EFORT Open Rev 2016;1:383-390. DOI: 10.1302/2058-5241.1.160024.

The Effectiveness of Platelet-Rich Plasma in the Treatment of Tendinopathy: A Meta-analysis of Randomized Controlled Clinical Trials

BACKGROUND

Tendinopathy is very common in the general population. There are increasing numbers of clinical studies referring to platelet-rich plasma (PRP) and platelet-poor plasma (PPP) as treatments for tendinopathy.

PURPOSE

To perform a meta-analysis of the outcomes of the PRP groups by preparation method and injection technique in tendinopathy. To determine the clinical effectiveness of the preparations and to evaluate the effect of controls used in the studies reviewed.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The PubMed, EMBASE, CINAHL, and Medline databases were searched in March 2012, April 2014, and August 2015, and randomized controlled trials using autologous blood, PRP, PPP, or autologous conditioned plasma in tendinopathy with outcome measures of pain and follow-up time of 3 months were included in this review. Trials including surgery, tendon tears, and muscle or ligament injuries were excluded. Study quality was assessed using the Cochrane Collaboration risk-of-bias tool by 2 reviewers. Data were pooled using random-effects meta-analysis. The primary outcome measure was a change in pain intensity. Where more than 1 pain scale was included, a functional score was selected ahead of a visual analog scale score.

RESULTS

A total of 18 studies (1066 participants) were included. Eight studies were deemed to be at low risk of bias. The most significant outcomes in the PRP groups were seen in those treated with highly cellular leukocyte-rich PRP (LR-PRP) preparations: GPS kit (standardized mean difference [SMD], 35.75; 95% CI, 28.40-43.10), MyCells kit (SMD, 31.84; 95% CI, 17.56-46.13), Prosys kit (SMD, 42.99; 95% CI, 37.73-48.25), and unspecified LR-PRP (SMD, 34.62; 95% CI, 31.69-37.55). When the LR-PRP system types were grouped, there was a strongly positive effect (SMD, 36.38; 95% CI, 34.00-38.77) when compared with leukocyte-poor PRP (SMD, 26.77; 95% CI, 18.31-35.22). In assessing the control groups, there was no clear difference between different types of control injections: saline (SMD, 14.62; 95% CI, 10.74-18.50), local anesthetic (SMD, 15.00; 95% CI, 7.66-22.34), corticosteroid (SMD, 23.82; 95% CI, 10.74-18.50), or dry needling (SMD, 25.22; 95% CI, 21.27-29.16).

CONCLUSION

There is good evidence to support the use of a single injection of LR-PRP under ultrasound guidance in tendinopathy. Both the preparation and intratendinous injection technique of PRP appear to be of great clinical significance.

A Prospective Study of Platelet-Rich Plasma as Biological Augmentation for Acute Achilles Tendon Rupture Repair

Acute Achilles tendon rupture is one of the most common tendon injuries in adults. We hypothesized that Platelet-Rich Plasma (PRP) can be used as biological augmentation for surgical treatment of acute Achilles tendon rupture. Our study is a prospective randomized controlled trial. Patients with acute Achilles tendon rupture undergoing surgical repair were randomly assigned into either control group or PRP group. End-to-end modified Krackow suture was performed in both groups. In the PRP group, PRP was injected into the paratenon sheath and around the ruptured tissue after the tendon was repaired. Postoperatively we evaluated isokinetic muscle strength at 3, 6, 12, and 24 months. In addition, ankle ROM, calf circumference, Leppilahti score, and the SF-36 score were evaluated at 6, 12, and 24 months after operation. At 3 months, the PRP group had better isokinetic muscle. The PRP group also achieved higher SF-36 and Leppilahti scores at 6 and 12 months. At 24 months, the PRP group had an improved ankle range of motion compared to the control group. Our study results suggest that PRP can serve as a biological augmentation to acute Achilles tendon rupture repair and improves both short and midterm functional outcomes.

Platelet-Rich Plasma Injections With Needle Tenotomy for Gluteus Medius Tendinopathy: A Registry Study With Prospective Follow-up

BACKGROUND

Gluteal tendinopathy is a prevalent condition that can be associated with significant pain and disability. To date, no studies have prospectively assessed the efficacy of intratendinous platelet-rich plasma (PRP) injections as a minimally invasive treatment for gluteus medius tendinopathy.

PURPOSE

To prospectively assess the efficacy of intratendinous PRP injections as treatment for chronic recalcitrant gluteus medius tendinopathy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

During the study period between July 2011 and November 2015, data were collected from the Hospital for Special Surgery Center for Hip Preservation Outcomes Registry on participants who underwent ultrasound-guided intratendinous PRP injections for recalcitrant gluteus medius tendinosis and/or partial tears of the tendon associated with moderate to severe lateral hip pain for longer than 3 months. All participants were assessed pre- and postinjection with 4 outcome measures: modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living subscale (HOS-ADL), Hip Outcome Score-Sport-Specific subscale (HOS-Sport), and the International Hip Outcome Tool-33 (iHOT-33). Demographic data, including age, sex, height, weight, body mass index, and smoking status, were also collected.

RESULTS

A total of 21 patients were included in the study, with a mean follow-up of 19.7 months (range, 12.1-32.3 months). The mean improvements from preinjection to postinjection follow-up were 56.73 to 74.17 for mHHS, 68.93 to 84.14 for HOS-ADL, 45.54 to 66.72 for HOS-Sport, and 34.06 to 66.33 for iHOT-33. All mean outcome measure improvements were clinically and statistically significant (P < .001). Length of follow-up was positively correlated with improvements in HOS-ADL (P = .021) and HOS-Sport (P = .004) scores. No adverse events were observed during or after the procedure.

CONCLUSION

In this registry study with prospective follow-up, we found ultrasound-guided intratendinous PRP injections to be a safe and effective treatment option for chronic recalcitrant gluteus medius tendinopathy due to moderate to severe tendinosis and/or partial tendon tears. Well-powered randomized controlled studies are warranted to confirm our findings and further define the ideal candidates for this treatment.

Efficacy of autologous leukocyte-reduced platelet-rich plasma therapy for patellar tendinopathy in a rat treadmill model

BACKGROUND

An autologous platelet-rich plasma (PRP) therapy has currently been applied for the tendinopathy; however, its efficacy and an optimal platelets concentration in PRP were uncertain. We analyzed them in an animal model prepared using a repetitive running exercise.

METHODS

We made the tendinopathy rat model of patellar tendon using a rodent treadmill machine. Rats with tendinopathy were injected with leukocyte-reduced PRP at the platelets concentration of 1.0×10⁶/μL (P10 group), PRP at the platelets concentration of 5.0×10⁵/μL (P5 group) or normal saline (control group) into the space between the patellar tendon and the fat pad bilaterally or were multiply dry-needled at the tibial insertion site (MN group) at once. To assess the pain-reliving effect, the spontaneous locomotor activities at night (12 h) were measured every day. Histological sections of the patellar tendon stained with hematoxylineosin or prepared by TdT-mediated dUTP nick end labeling were microscopically analyzed.

RESULTS

The numbers of spontaneous locomotor activities in the P10 group were significantly larger than those in the P5, MN or control groups and they recovered up to a healthy level. On histologic examinations, the numbers of microtears, laminations, or apoptotic cells in the patellar tendons in the P10 or P5 groups were significantly lower than those in the MN or control groups, although no significant differences were observed between the P10 and P5 groups.

CONCLUSIONS

The injections of an autologous leukocyte-reduced PRP were effective for pain relief and for partial restoration of the patellar tendon in the tendinopathy rat model. The injections of a PRP at the platelets concentration of 1.0×10⁶/μL completely relieved the pain and were more effective than those at the platelets concentration of 5.0×10⁵/μL whereas there was no difference for the effect of histological restoration or apoptosis inhibition between them.

Foot and Ankle Injuries in Runners

Foot and ankle injuries account for nearly one-third of running injuries. Achilles tendinopathy, plantar fasciopathy, and ankle sprains are 3 of the most common types of injuries sustained during training. Other common injuries include other tendinopathies of the foot and ankle, bone stress injuries, nerve conditions including neuromas, and joint disease including osteoarthritis. This review provides an evidence-based framework for the evaluation and optimal management of these conditions to ensure safe return to running participation and reduce risk for future injury.

Ultrasound-Guided Injection Therapy of Achilles Tendinopathy With Platelet-Rich Plasma or Saline: A Randomized, Blinded, Placebo-Controlled Trial

BACKGROUND

Achilles tendinopathy (AT) is a common and difficult to treat musculoskeletal disorder.

PURPOSE

To examine whether 1 injection of platelet-rich plasma (PRP) would improve outcomes more effectively than placebo (saline) after 3 months in patients with AT.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 24 patients with chronic AT (median disease duration, 33 months) were randomized (1:1) to receive either a blinded injection of PRP (n = 12) or saline (n = 12). The primary endpoint was improvement in Victorian Institute of Sports Assessment-Achilles (VISA-A) score at 3 months. Secondary outcomes were pain at rest, pain while walking, pain when tendon was squeezed, ultrasonographic changes in tendon thickness, and color Doppler activity. Patients were informed that they could drop out after 3 months if they were dissatisfied with the treatment.

RESULTS

After 3 months, all 24 patients were reassessed (no dropouts). No difference between the PRP and the saline group could be observed with regard to the primary outcome (VISA-A score: mean difference [MD], -1.3; 95% CI, -17.8 to 15.2; P = .868). Secondary outcomes were pain at rest (MD, 1.6; 95% CI, -0.5 to 3.7; P = .137), pain while walking (MD, 0.8; 95% CI, -1.8 to 3.3; P = .544), pain when tendon was squeezed (MD, 0.3; 95% CI, -0.2 to 0.9; P = .208), color Doppler activity (MD, 0.3; 95% CI, -0.2 to 0.8; P = .260), and tendon thickness (MD, 0.8 mm; 95% CI, 0.1 to 1.6 mm; P = .030). After the 3-month follow-up, a large dropout was observed: 75% of patients in the PRP group and 33% in the saline group.

CONCLUSION

PRP injection did not result in an improved VISA-A score over a 3-month period in patients with chronic AT compared with placebo. The only secondary outcome demonstrating a statistically significant difference between the groups was change in tendon thickness; this difference indicates that a PRP injection could increase tendon thickness compared with saline injection. The conclusions are limited to the 3 months after treatment owing to the large dropout rate.

What does normal tendon structure look like? New insights into tissue characterization in the Achilles tendon

Recently, ultrasound tissue characterization (UTC) was introduced as a reliable method for quantification of tendon structure. Despite increasing publications on the use of UTC, it is striking that there is a lack of normative data in active adolescents. Therefore, the aim of this study was to provide normative values of the Achilles tendon as quantified by UTC. Seventy physiotherapy students (26 male and 44 female students) with no history of Achilles tendon injuries were recruited. The Achilles tendons were scanned with UTC to characterize tendon structure. This study demonstrated that Achilles tendons of active, healthy adolescents contained 54.6% echo type I, 42.8% echo type II, 2.2% echo type III, and 0.3% echo type IV at midportion. The comparison between insertion and midportion of the tendon showed more echo type II at insertion (P < 0.001). Furthermore, female tendons contained significantly more echo type II, in both insertion and midportion compared with male tendons (P = 0.004 and P = 0.003, respectively). The results of this study, with respect to the MDC (minimum detectable change), highlight differences in the UTC echopattern in the normal population (sex and regional location), which are important considerations for future studies.

Treatment of midportion Achilles tendinopathy: an evidence-based overview

In Achilles tendinopathy, differentiation should be made between paratendinopathy, insertional- and midportion Achilles tendinopathy. Midportion Achilles tendinopathy is clinically characterized by a combination of pain and swelling at the affected site, with impaired performance as an important consequence. The treatment of midportion Achilles tendinopathy contains both non-surgical and surgical options. Eccentric exercise has shown to be an effective treatment modality. Promising results are demonstrated for extracorporeal shockwave therapy. In terms of the surgical treatment of midportion Achilles tendinopathy, no definite recommendations can be made.

LEVEL OF EVIDENCE

IV.

Ultrasound-guided dry needling with percutaneous paratenon decompression for chronic Achilles tendinopathy

PURPOSE

Chronic Achilles tendinopathy is a common overuse injury. There are several modalities of treatment, reflecting difficulties in management. In particular, due to the well-recognised surgical morbidity, treatment has steered towards less invasive routes. Previous studies have targeted pathology either inside or outside the tendon in isolation with varying results. This study aimed to target both pathological sites by combining dry needling with percutaneous hydrostatic decompression as a novel treatment.

METHODS

Twenty-one patients with 26 chronic, non-insertional Achilles tendinopathy were prospectively enrolled. Ultrasound-guided dry needling of neovascular areas and small-volume hydrostatic paratenon decompression was performed 6-weekly. Sonographic assessment of tendon thickness and neovascularity was undertaken. Following treatment, a standardised physiotherapy regime was adopted. Visual analogue scores (VAS) were used as the primary outcome measure. Telephonic interviews were carried out 12 and 24 months post-treatment.

RESULTS

Twenty-four tendons (in 19 patients) were successfully treated. The mean treatment session was 2. There was no significant change in neovascularity or tendon thickness. Therapeutic intervention led to a significant improvement in VAS at rest (42.4 ± 24.4 vs. 18.4 ± 26.0, p = 0.0005) and during activity (72.8 ± 16.0 vs. 33.7 ± 23.2, p < 0.0001). At 12 and 24 months, >75 % of patients were highly satisfied with their outcome with nearly half reporting complete resolution of their symptoms. >85 % were also able to return to their sporting interests.

CONCLUSION

Combined therapy of dry needling with percutaneous hydrostatic paratenon decompression under ultrasound guidance is a well-tolerated procedure with good short- and long-term pain and functional outcomes.

LEVEL OF EVIDENCE

Prospective case series, Level IV.

Biological Treatments for Tendon and Ligament Abnormalities: A Critical Analysis Review

The poor intrinsic healing potential of tendon and ligamentous tissue has driven the search for biological agents that can improve healing, most notably platelet-rich plasma (PRP) and autologous stem cells. Current evidence best supports the use of PRP as treatment for chronic, degenerative tendinopathies such as lateral epicondylitis of the elbow or patellar tendinopathy. It does not support the use of PRP to promote tendon or ligament-to-bone healing in rotator cuff repair or anterior cruciate ligament (ACL) reconstruction. Clinical evidence regarding the use of autologous stem cells as treatment for tendon and ligament abnormalities is currently limited. However, the initial results appear to be promising, particularly following rotator cuff repair. A major limitation in the evaluation of current data is the lack of standardization in the preparation and composition of PRP, which are often not reported. Future investigators should make an effort to report the method of preparation and final composition of PRP used. Autologous stem cells were most often harvested from bone marrow aspirate but were occasionally derived from dermal tenocyte cells. Recent studies have explored new sources for stem cells, including adipose tissue, peripheral blood, and human amniotic tissue. We expect that clinical data evaluating these treatments will soon emerge.

Application of Tendon Stem/Progenitor Cells and Platelet-Rich Plasma to Treat Tendon Injuries

Tendon injuries like tendinopathy are a serious healthcare problem in the United States. However, current treatments for tendon injuries are largely palliative. Biologics treatments, including tendon stem/progenitor cells (TSCs) and platelet rich plasma (PRP) hold great potential to effectively treat tendon injuries. TSCs are tendon specific stem cells and have the ability to differentiate into tenocytes, the resident tendon cells responsible for tendon homeostasis and tendon repair in case of an injury. TSCs can also self-renew and thus can replenish the tendon with tendon cells (TSCs and tenocytes) to maintain a healthy tendon. The action of PRP can be complementary; PRP can augment and accelerate tendon healing by supplying abundant growth factors contained in platelets, and fibrin matrix, which functions as a natural conducive scaffold to facilitate tissue healing. This article provides a summary of the findings in recent basic and clinical studies on the applications of TSCs and PRP to the treatment of tendon injuries. It also outlines the challenges facing their applications in clinical settings. In particular, the controversy surrounding the efficacy of PRP treatment for tendon injuries are analyzed and solutions are suggested.

Open surgical treatment for chronic midportion Achilles tendinopathy: faster recovery with the soleus fibres transfer technique

PURPOSE

The study aimed to compare two methods of open surgical treatment for midportion Achilles tendinopathy in sportsmen. A novel technique consisting in transferring some soleus fibres into the degenerated tendon to improve its vascularization and longitudinal tenotomies are evaluated and compared.

METHODS

From 2006 to 2011, fifty-two competitive and noncompetitive athletes affected by midportion Achilles tendinopathy were surgically treated and prospectively evaluated at 6 months and at a final 4-year mean follow-up. Twenty patients had longitudinal tenotomies, and thirty-two had soleus fibres transfer. Clinical outcome was evaluated by the American Orthopaedic Foot and Ankle Society (AOFAS) score and the Victorian Institute of Sports Assessment-Achilles (VISA-A) score. Time to return to walk and to run and tendon thickening were also recorded.

RESULTS

Patients in the soleus transfer group had a higher increase in AOFAS and VISA-A score at 6 months and at the mean 4-year final follow-up (by 5.4 points, 95 % CI 2.9-7.9, p < 0.001 and by 5.7 points, 95 % CI 2.5-8.9, p = 0.001, for AOFAS and VISA, respectively). They also needed less time to return to run: 98.9 ± 17.4 days compared to 122.2 ± 26.3 days for the longitudinal tenotomies group (p = 0.0019). The soleus transfer group had a greater prevalence of tendon thickening (59.4 % compared to 30.0 % in the longitudinal tenotomies group, p = 0.037).

CONCLUSIONS

Open surgery for midportion Achilles tendinopathy is safe and effective in medium term. Despite similar outcomes in postoperative functional scores, soleus transfer allows a faster recovery but has a higher incidence of tendon thickening. These results should suggest the use of the soleus graft technique in high-level athletes.

LEVEL OF EVIDENCE

Prospective comparative study, Level II.

A systematic review and meta-analysis of the application of platelet rich plasma in sports medicine

Introduction

In recent years, platelet rich plasma (PRP) has been receiving increasing attention for the treatment of soft tissue injuries. These numerous applications have raised a great deal of questions and debate about the effectiveness of this method. This study aimed to determine the efficacy of PRP in improving sports injuries and subsequently throw some light on these controversies.

Methods

A systematic review of the literature and meta-analysis of results were undertaken. All related databases, such as PubMed, Cochrane Database of Systematic Reviews, DARE, and EMBASE, were searched on the use of PRP on athletes and in sports medicine. The search was conducted from June 2013 to February 2014.

Results

Our search retrieved 905 studies, of which 13 randomized control trials (RCT) met our inclusion criteria for systematic review and meta-analysis. All articles were appraised by Critical Appraisal Skills Program (CASP) checklist for RCT studies. The analysis of the results of pain scores and physical activity/functions did not show any superiority for PRP as opposed to the other options.

Conclusions

The meta-analysis showed no more effectiveness for PRP application in sports-related injuries in terms of physical function improvement and pain relief. Therefore, the extensive use of PRP for such injuries should be limited. Well-designed RCTs are needed to support the findings.

Autologous platelet-rich plasma: evidence for clinical use

PURPOSE OF REVIEW

Autologous platelet-rich plasma (aPRP) is growing in popularity as a therapy to augment wound healing, speed the recovery from muscle and joint injuries, and enhance recovery after surgical repair. High-profile athletes treated with aPRP have increased the demand from the general population. Yet, evidence to support the use of aPRP in most clinical settings is weak, because of poorly controlled clinical trials.

RECENT FINDINGS

Preparations of aPRP vary by platelet count, leukocyte content, and degree of platelet activation. Nonetheless, these heterogeneous preparations are used in trials to assess the efficacy of aPRP treatment.

SUMMARY

Despite weak evidence, the use of aPRP continues to grow. High-quality randomized controlled trials are needed to validate or repudiate the potential efficacy of aPRP. Standards for aPRP preparation and quality should be created.

[Muscle, tendon and joint injections : What is the evidence?]

Injections at tendon insertions, in muscles and in joints are an important instrument in the conservative treatment of musculoskeletal diseases, for acute injuries as well as for chronic degenerative diseases. Local anesthetic agents and glucocorticoids are well-established medications; however, severe side effects, such as chondrolysis have sometimes been reported, particularly for local anesthetic agents. In addition platelet rich plasma (PRP) and hyaluronic acid are also widely used; however, the clinical effectiveness has not always been proven. This article gives an overview on the most commonly used medications for injections and the mechanisms of action. The indications for treatment and the evidence for the clinical adminstration of muscle, tendon and joint injections are described based on the currently available literature.