Types and epidemiology of tendinopathy

Effects of Hypoxia and Chitosan on Equine Umbilical Cord-Derived Mesenchymal Stem Cells

Chitosan opens new perspectives in regenerative medicine as it enhances the properties of mesenchymal stem cells (MSCs) through formation of spheroids. Hypoxia has also been proposed to enhance stemness and survival of MSCs after in vivo implantation. These characteristics are relevant to the development of an off-the-shelf source of allogenic cells for regenerative therapy of tendinopathies. Umbilical cord-derived MSCs (UCM-MSCs) offer an abundant source of immature and immunoprivileged stem cells. In this study, equine UCM-MSCs (eqUCM-MSCs) conditioned for 3 and 7 days on chitosan films at 5% oxygen were compared to eqUCM-MSCs under standard conditions. Equine UCM-MSCs formed spheroids on chitosan but yielded 72% less DNA than standard eqUCM-MSCs. Expression of Sox2, Oct4, and Nanog was 4 to 10 times greater in conditioned cells at day 7. Fluorescence-labeled cells cultured for 7 days under standard conditions or on chitosan films under hypoxia were compared in a bilateral patellar tendon defect model in rats. Fluorescence was present in all treated tendons, but the modulus of elasticity under tension was greater in tendons treated with conditioned cells. Chitosan and hypoxia affected cell yield but improved the stemness of eqUCM-MSCs and their contribution to the healing of tissues. Given the abundance of allogenic cells, these properties are highly relevant to clinical applications and outweigh the negative impact on cell proliferation.

Nutraceutical supplement in the management of tendinopathies: a systematic review

BACKGROUND

nutraceuticals are common support therapy for management of tendinopathies. Even if they are widely diffused, our knowledge is still poor. The aim of this systematic review is to analyze the most commonly used nutraceuticals and their effects on tendons.

METHODS

glucosamine and chondroitin sulphate, vitamin C, hydrolazed type 1 collagen, arginine alpha-keto-glutarate, bromelain, curcumin, boswellic acid, and methil-sulfonil-methane were considered. During the last week of Dicember 2015 a comprehensive research of main databases for each substance was made in relation with tendinopathy. Repeated articles, articles not in English nor in Italian, not common nutraceuticals, and articles not related with tendons or tenocytes were excluded. Clinical article quality was assessed independently by two reviewers using the modified Coleman methodology score.

RESULTS

preclinical and clinical data from 46 articles from all databases were analyzed. All these nutraceuticals demonstrated several effects on normal and pathological tendons. Preclinical and clinical studies showed a possible role on collagen synthesis, inflammation, mechanical properties, and maturation of collagen bundles, antioxidant effect, edema, and analgesia. The majority clinical studies had some methodological limitations with an average Modified Coleman Methodology Score of 51.3 points and SD of 20.5 points. In particular, there were very low values in power, error, outcome assessment, and clinical effect.

CONCLUSION

preclinical results are very encouraging, however they are not fully confirmed by clinical studies. There are few clinical papers on the use of nutraceuticals in tendon disorders, and their methodological quality is poor. Furthermore, in most of the studies more than one supplement was administered at the same time. This may bias the results, and the effect of each single component cannot be determined. Furthermore, the interactions between nutraceuticals and drugs, or other dietary supplements (especially at high doses) has not been evaluated, neither their effects on chronic diseases. For these reasons, it is not possible to draw any definitive raccomendations on the use of nutraceutical supplementation in tendinopathies.

Exercise and load modification versus corticosteroid injection versus 'wait and see' for persistent gluteus medius/minimus tendinopathy (the LEAP trial): a protocol for a randomised clinical trial

Background

Lateral hip pain is common, particularly in females aged 40–60 years. The pain can affect sleep and daily activities, and is frequently recalcitrant. The condition is often diagnosed as trochanteric bursitis, however radiological and surgical studies have revealed that the most common pathology is gluteus medius/minimus tendinopathy. Patients are usually offered three treatment options: (a) corticosteroid injection (CSI), (b) physiotherapy, or (c) reassurance and observation. Research on Achilles and patellar tendons has shown that load modification and exercise appears to be more effective than other treatments for managing tendinopathy, however, it is unclear whether a CSI, or a load modification and exercise-based physiotherapy approach is more effective in gluteal tendinopathy. This randomised controlled trial aims to compare the efficacy on pain and function of a load modification and exercise-based programme with a CSI and a ‘wait and see’ approach for gluteal tendinopathy.

Methods

Two hundred one people with gluteal tendinopathy will be randomly allocated into one of three groups: (i) CSI; (ii) physiotherapist-administered load modification and exercise intervention; and (iii) wait and see approach. The CSI therapy will consist of one ultrasound (US) guided CSI around the affected tendons and advice on tendon care. Education about load modification will be delivered in physiotherapy clinics and the exercise programme will be both home-based and supervised. The group allocated the wait and see approach will receive basic tendon care advice and reassurance in a single session by a trial physiotherapist. Outcomes will be evaluated at baseline, 4, 8, 12, 26 and 52 weeks using validated global rating of change, pain and physical function scales, psychological measures, quality of life and physical activity levels. Hip abductor muscle strength will be measured at baseline and 8 weeks. Economic evaluation will be performed to investigate the cost-effectiveness of the active interventions compared with the wait and see approach. Analyses will be conducted on an intention-to-treat basis using logistic and linear mixed regression models and the economic evaluation will report incremental cost-utility ratios. The trial reporting will comply with CONSORT guidelines.

Discussion

This study will provide clinicians with directly applicable evidence of the relative efficacy of three common approaches to the management of gluteal tendinopathy.

Trial registration

Australia New Zealand Clinical Trials Registry ACTRN12612001126808. Date Registered: 22/10/2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1043-6) contains supplementary material, which is available to authorized users.

Therapeutic Roles of Tendon Stem/Progenitor Cells in Tendinopathy

Tendinopathy is a tendon disorder characterized by activity-related pain, local edema, focal tenderness to palpation, and decreased strength in the affected area. Tendinopathy is prevalent in both athletes and the general population, highlighting the need to elucidate the pathogenesis of this disorder. Current treatments of tendinopathy are both conservative and symptomatic. The discovery of tendon stem/progenitor cells (TSPCs) and erroneous differentiation of TSPCs have provided new insights into the pathogenesis of tendinopathy. In this review, we firstly present the histopathological characteristics of tendinopathy and explore the cellular and molecular cues in the pathogenesis of tendinopathy. Current evidence of the depletion of the stem cell pool and altered TSPCs fate in the pathogenesis of tendinopathy has been presented. The potential regulatory factors for either tenogenic or nontenogenic differentiation of TSPCs are also summarized. The regulation of endogenous TSPCs or supplementation with exogenous TSPCs as therapeutic targets for the treatment of tendinopathy is proposed. Therefore, inhibiting the erroneous differentiation of TSPCs and regulating the differentiation of TSPCs into tendon cells might be important areas of future research and could provide new clinical treatments for tendinopathy. The current evidence suggests that TSPCs are promising therapeutic targets for the management of tendinopathy.

The Role of Detraining in Tendon Mechanobiology

Introduction: Several conditions such as training, aging, estrogen deficiency and drugs could affect the biological and anatomo-physiological characteristics of the tendon. Additionally, recent preclinical and clinical studies examined the effect of detraining on tendon, showing alterations in its structure and morphology and in tenocyte mechanobiology. However, few data evaluated the importance that cessation of training might have on tendon. Basically, we do not fully understand how tendons react to a phase of training followed by sudden detraining. Therefore, within this review, we summarize the studies where tendon detraining was examined.

Materials and Methods: A descriptive systematic literature review was carried out by searching three databases (PubMed, Scopus and Web of Knowledge) on tendon detraining. Original articles in English from 2000 to 2015 were included. In addition, the search was extended to the reference lists of the selected articles. A public reference manager (www.mendeley.com) was adopted to remove duplicate articles.

Results: An initial literature search yielded 134 references (www.pubmed.org: 53; www.scopus.com: 11; www.webofknowledge.com: 70). Fifteen publications were extracted based on the title for further analysis by two independent reviewers. Abstracts and complete articles were after that reviewed to evaluate if they met inclusion criteria.

Conclusions: The revised literature comprised four clinical studies and an in vitro and three in vivo reports. Overall, the results showed that tendon structure and properties after detraining are compromised, with an alteration in the tissue structural organization and mechanical properties. Clinical studies usually showed a lesser extent of tendon alterations, probably because preclinical studies permit an in-depth evaluation of tendon modifications, which is hard to perform in human subjects. In conclusion, after a period of sudden detraining (e.g., after an injury), physical activity should be taken with caution, following a targeted rehabilitation program. However, further research should be performed to fully understand the effect of sudden detraining on tendons.

A practical guide for the isolation and maintenance of stem cells from tendon

Stem cells are unspecialized cells that can self-renew and have the ability to develop into cells of highly specialized functions. The study of stem cells holds enormous promise in the medical field ranging from their uses in cell therapies to their uses for greater understanding of tissue development and disease pathologies. Stem cells have been isolated from tendon tissue recently. These tendon-derived stem cells (TDSCs) are particularly relevant for tendon repair and the study of the potential roles of stem cells in tendon pathology as they are isolated from tendon tissues. This paper aims to describe the step-by-step protocol and the practical tips for the isolation and verification of stem cell characteristics of TDSCs. The cell seeding density and hence cell-cell contact has a significant impact on the isolation and expansion of TDSCs. Hence, I also describe our established protocol for the determination of the optimal seeding density for TDSC isolation and culture.

Common sports-related musculoskeletal injuries presenting to the emergency department

Young athletes are specialising in sports at a younger age, placing the developing musculoskeletal system under considerable stress. Overuse injuries such as apophysitis are chronic in nature and account for a large proportion of musculoskeletal injuries suffered by young athletes; however, with an increased emphasis on success in sport, tendinopathy and fatigue fractures are now being reported with increasing frequency, in the adolescent population. Correct diagnosis and early protection, rest, ice, compression and elevation therapy is critical, along with supervised rehabilitation an expert in paediatric and adolescent sports medicine. Acute traumatic knee injury and ankle sprain account for most acute injuries. Although most are soft tissue in nature, radiography may be useful in specific situations before early initiation of protection, rest, ice, compression and elevation therapy. These injuries will also require follow-up by an expert in paediatric and adolescent sports medicine to confirm the diagnosis and instigate ongoing rehabilitation and/or orthopaedic referral. Many of these injuries are preventable and due consideration should be given to simple prevention strategies.

The sympathetic nervous system and tendinopathy: a systematic review

BACKGROUND

Tendinopathy is a clinical diagnosis of localised tendon pain often confirmed by imaging findings. The pathophysiological cause of the pain is unknown and the sympathetic nervous system (SNS) may be implicated.

OBJECTIVE

To review what is known regarding the role of the SNS in human tendinopathy.

STUDY SELECTION

Published data describing sympathetic innervation or an index of sympathetic activity in human tendons were eligible for inclusion.

DATA SOURCES

Bibliographical databases (AMED, Biological Abstracts, CINAHL Plus, EMBASE, MEDLINE, Scopus, SPORTDiscus and Web of Science) were searched for relevant articles. Reference lists from included articles were screened for additional articles.

STUDY APPRAISAL

Studies were scored with a quality assessment tool to identify potential sources of bias. Each question had an explicit decision rule to guide assessment.

RESULTS

Nine case-control and four cross-sectional studies examined sympathetic innervation of tendons. There was evidence suggesting a lack of difference in sympathetic innervation of tendon proper between tendinopathy biopsies and healthy controls. In contrast, the paratendinous tissue showed evidence of increased sympathetic innervation in painful tendons. The most notable increase in SNS markers was seen in abnormal tenocytes from painful tendons. Data from two studies were suitable for meta-analysis. These heterogeneous studies revealed no difference in sympathetic innervation between painful and pain-free tendons. No studies recorded SNS activity in vivo.

CONCLUSION

Sympathetic innervation in painful tendons depends on tissue type. Abnormal tenocytes may have increased capacity for self-production of sympathetic neurotransmitters. Future insight may be gained by measuring global in vivo sympathetic drive in tendinopathy.

Incidence and prevalence of lower extremity tendinopathy in a Dutch general practice population: a cross sectional study

Background

Lower extremity tendinopathy is a common sports injury, but it can also affect non-athletes. Because tendinopathy is difficult to treat and has negative effects on the ability to work and quality of life, development of preventive interventions is important. The first step in the Van Mechelen prevention model is to determine the extent of the problem. The primary aim of this study was to determine the incidence and prevalence of lower extremity tendinopathy in a Dutch general practice population. The secondary aim was to investigate possible associated factors.

Methods

A cross-sectional study was performed in a Dutch general practice. Using International Classification of Primary Care codes, the electronic patient files were searched to identify cases of adductor tendinopathy, greater trochanteric pain syndrome, jumper’s knee, Achilles tendinopathy, and plantar fasciopathy in 2012. The tendinopathy patients were compared to the general practice population regarding age, gender, use of medication, and comorbidity using 95 % confidence intervals.

Results

The prevalence and incidence rates of lower extremity tendinopathy found in this study were 11.83 and 10.52 per 1000 person-years. Lower extremity tendinopathy was more prevalent among older patients. No differences between tendinopathy patients and the general practice population were found regarding gender, use of medication, or comorbidity.

Conclusions

In this cross-sectional study in a Dutch general practice, the prevalence and incidence rates of lower extremity tendinopathy were 11.83 and 10.52 per 1000 person-years. Lower extremity tendinopathy deserves a higher place in locomotor system research to develop preventive interventions.

Cytotoxic and sublethal effects of silver nanoparticles on tendon-derived stem cells - implications for tendon engineering

Tendon injuries occur commonly in sports and workplace. Tendon-derived stem cells (TDSCs) have great potential for tendon healing because they can differentiate into functional tenocytes. To grow TDSCs properly in vivo, a scaffold is needed. Silver nanoparticles (AgNPs) have been used in a range of biomedical applications for their anti-bacterial and -inflammatory effects. AgNPs are therefore expected to be a good scaffolding coating material for tendon engineering. Yet, their cytotoxicity in TDSCs remains unknown. Moreover, their sublethal effects were mysterious in TDSCs. In our study, decahedral AgNPs (43.5 nm in diameter) coated with polyvinylpyrrolidone (PVP) caused a decrease in TDSCs' viability beginning at 37.5 μg ml-1 but showed non-cytotoxic effects at concentrations below 18.8 μg ml-1. Apoptosis was observed in the TDSCs when higher doses of AgNPs (75-150 μg ml-1) were used. Mechanistically, AgNPs induced reactive oxygen species (ROS) formation and mitochondrial membrane potential (MMP) depolarization, resulting in apoptosis. Interestingly, treating TDSCs with N-acetyl-l-cysteine (NAC) antioxidant significantly antagonized the ROS formation, MMP depolarization and apoptosis indicating that ROS accumulation was a prominent mediator in the AgNP-induced cytotoxicity. On the other hand, AgNPs inhibited the tendon markers' mRNA expression (0-15 μg ml-1), proliferation and clonogenicity (0-15 μg ml-1) in TDSCs under non-cytotoxic concentrations. Taken together, we have reported here for the first time that the decahedral AgNPs are cytotoxic to rat TDSCs and their sublethal effects are also detrimental to stem cells' proliferation and tenogenic differentiation. Therefore, AgNPs are not a good scaffolding coating material for tendon engineering.

Stem cell technology for tendon regeneration: current status, challenges, and future research directions

Tendon injuries are a common cause of physical disability. They present a clinical challenge to orthopedic surgeons because injured tendons respond poorly to current treatments without tissue regeneration and the time required for rehabilitation is long. New treatment options are required. Stem cell-based therapies offer great potential to promote tendon regeneration due to their high proliferative, synthetic, and immunomodulatory activities as well as their potential to differentiate to the target cell types and undergo genetic modification. In this review, I first recapped the challenges of tendon repair by reviewing the anatomy of tendon. Next, I discussed the advantages and limitations of using different types of stem cells compared to terminally differentiated cells for tendon tissue engineering. The safety and efficacy of application of stem cells and their modified counterparts for tendon tissue engineering were then summarized after a systematic literature search in PubMed. The challenges and future research directions to enhance, optimize, and standardize stem cell-based therapies for augmenting tendon repair were then discussed.

The Tendon Structure Returns to Asymptomatic Values in Nonoperatively Treated Achilles Tendinopathy but Is Not Associated With Symptoms: A Prospective Study

BACKGROUND

Tendinopathy is characterized by alterations in the tendon structure, but there are conflicting results on the potential of tendon structure normalization and no large studies on the quantified, ultrasonographic tendon structure and its association with symptoms.

PURPOSE

To determine whether the tendon structure returns to values of asymptomatic individuals after treatment with 2 substances injected within the tendon, to assess the association between the tendon structure and symptoms, and to assess the prognostic value of the baseline tendon structure on treatment response.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This study was part of a randomized trial on chronic midportion Achilles tendinopathy using eccentric exercises with either a platelet-rich plasma or saline injection. Symptoms were recorded using the Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire. The tendon structure was quantified with ultrasound tissue characterization (UTC); echo types I + II (as a percentage of total tendon types I-IV) are structure related. Follow-up was at 6, 12, 24, and 52 weeks. A control group of asymptomatic subjects (similar age) was selected to compare the tendon structure. Patient symptoms were correlated with the tendon structure using a linear model.

RESULTS

Fifty-four patients were included in the symptomatic group. The mean (± SD) echo types I + II in the symptomatic group increased significantly from 74.6% ± 10.8% at baseline to 85.6% ± 6.0% at 24-week follow-up. The result for echo types I + II at 24 weeks was not significantly different (P = .198) from that of the asymptomatic control group (87.5% ± 6.0%). In 54 repeated measurements at 5 time points, the adjusted percentage of echo types I + II was not associated with the VISA-A score (main effect: β = .12; 95% CI, -0.12 to 0.35; P = .338). The adjusted baseline echo types I + II were not associated with a change in the VISA-A score from baseline to 52 weeks (β = -.15; 95% CI, -0.67 to 0.36; P = .555).

CONCLUSION

In symptomatic, tendinopathic Achilles tendons, the ultrasonographic tendon structure improved during nonoperative treatment and normalized after 24 weeks to values of matched asymptomatic controls. There was no association between the tendon structure and symptoms. The percentage of echo types I + II before treatment was not associated with change in symptoms over time. This study demonstrates that restoration of the tendon structure is not required for an improvement of symptoms.

US for diagnosis of musculoskeletal conditions in the young athlete: emphasis on dynamic assessment

Ultrasonography (US) is increasingly recognized as an important tool for diagnosis and therapeutic management of a variety of musculoskeletal conditions. Advantages of US use in the young athlete include the ability to diagnose dynamic conditions that are occult with other modalities, provide additional diagnostic information, and aid in treatment. Uses of US in young patients include evaluation of acquired musculoskeletal conditions that manifest with symptoms and assessment of congenital variants that may manifest with pain or limitations in activity. Acquired conditions in the young athlete include tendon disorders, such as proximal tendinosis, and ligament disorders, such as anterior talofibular ligament or ulnar collateral ligament tears. While static images are frequently able to depict these disorders without difficulty, a dynamic examination that provides stress to the joint of interest may be able to uncover a ligament tear or insufficiency and concurrently provide the clinician with information regarding joint stability. Numerous congenital variants that occur throughout the musculoskeletal system can be associated with awkward sensations such as snapping, popping, and clunking and occasionally with pain. Pathologic processes associated with congenital variants in the upper extremities include slipping rib syndrome, atraumatic anterior subluxation of the sternoclavicular joint, and snapping triceps syndrome. Conditions that affect the lower extremities include internal and external snapping hip syndrome, snapping knee syndrome, and medial plica syndrome. The dynamic capability of US is ideal for diagnosis of many conditions that affect the musculoskeletal system of the young athlete, many of which would be difficult or impossible to identify with use of other imaging modalities.

Sustained acoustic medicine: wearable, long duration ultrasonic therapy for the treatment of tendinopathy

OBJECTIVES

The effectiveness of sustained acoustic medicine to alleviate pain and improve function in subjects with elbow or Achilles tendinopathy was evaluated through a level IV case series study. Subjects were trained to self-apply the wearable, long-duration, low-intensity ultrasonic device on their affected body part at home for 4 hours a day, at least 5 times per week over 6 weeks. Twenty-five subjects with clinician-diagnosed tendinopathy of the elbow (medial or lateral epicondyle) or Achilles tendon were enrolled.

METHODS

Pain measurements were recorded before, during, and after daily intervention using an 11-point numeric rating scale (NRS). Function of the injured limb was assessed biweekly using dynamometry. Repeated measures ANOVAs and paired-samples t-tests were used to examine the effect of treatment over time.

RESULTS

Among subjects with elbow tendinopathy (n = 20), a 3.94 ± 2.15 point reduction in pain (p = 0.002) was observed over the 6-week study and a 2.83 ± 5.52 kg improvement in grip strength (p = 0.04) was observed over the first two weeks. In addition, a significant reduction in pain was observed within the 4-h treatment sessions (p < 0.001). Among 5 subjects with Achilles tendinopathy, a reduction in pain and improvement in strength was also observed.

CONCLUSIONS

Daily multi-hour ultrasonic therapy was associated with improved pain and increased function in subjects with chronic tendon injuries. This trial showed the safety and feasibility of self-administration of sustained acoustic medicine, and suggests that this therapy may be clinically beneficial in the treatment of tendinopathies of the elbow and Achilles tendon. A randomized controlled trial appears warranted to more definitively investigate the therapeutic potential of this treatment modality. Registered at www.ClinicalTrials.gov, NCT02466308.

PAPP-A affects tendon structure and mechanical properties

Pregnancy-associated plasma protein-A (PAPP-A) serves to increase local insulin-like growth factor (IGF) stimulation of proliferation and differentiation in many tissues through proteolysis of inhibitory IGF-binding proteins. The purpose of this study was to investigate the effects of PAPP-A on tendon structure and mechanical properties. A total of 30 tails from 6-month-old mice were tested with 10 tails in each of following groups: PAPP-A knockout (KO), skeletal-specific PAPP-A overexpressing transgenic (Tg) and wild type (WT). Morphologically, the total tail cross-sectional area (CSA), individual tissue CSAs of bone, muscle and tendon, and fascicle diameter were measured. A fascicle pullout test was performed to assess stiffness and strength of interfascicular structures. Fascicles were mechanically characterized through low and high displacement rate uniaxial tension tests providing modulus at each rate, hysteresis area and stress relaxation ratio. The KO mice had a smaller total tail CSA (p<0.05), fascicle diameter (p<0.05), absolute tendon CSA (p<0.05), fast and slow stiffness (p<0.05 for both) and larger hysteresis area (p<0.05) compared to WT and Tg mice. On the other hand, the Tg mice had a larger fascicle diameter (p<0.05), absolute tendon CSA (p<0.05), higher interfascicular strength and stiffness (p<0.05) and lower fascicular modulus at low displacement rates (p<0.05) compared to WT and KO mice. Tg mice also had larger total tail CSA area (p<0.05) and smaller hysteresis area (p<0.05) than KO mice, and larger normalized tendon CSA (p<0.05) than WT mice. Based on these data, we conclude that PAPP-A affects fascicle structure, thereby affecting tendon phenotype.

Evidence for the Durability of Autologous Tenocyte Injection for Treatment of Chronic Resistant Lateral Epicondylitis: Mean 4.5-Year Clinical Follow-up

BACKGROUND

Chronic lateral epicondylitis (LE) induces cell apoptosis and autophagy, which lead to the reduction of tendon-derived cells in the torn tendon. Our previous study has shown that ultrasound-guided autologous tenocyte injection (ATI) to the torn tendon in patients with chronic resistant LE significantly improves pain, function, and structural repair at 1 year. This report is the continued assessment of the clinical outcomes of these patients at mean 4.5-year follow-up.

HYPOTHESIS

Improvements in LE clinical function and structural repair after ATI will be maintained at mean 4.5-year follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients with severe refractory LE underwent clinical evaluation and MRI before intervention. A patellar tendon needle biopsy was performed under local anesthetic, and tendon cells were expanded by in vitro culture. Autologous tenocytes were injected into the central tendinopathy identified at the common extensor tendon origin under ultrasound guidance on a single occasion. Patients underwent serial clinical evaluations for up to 5 years after ATI, including the visual analog scale (VAS) for pain, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), Upper Extremity Functional Scale (UEFS), and grip strength. Post-ATI MRI scanning was performed at 1 year and final follow-up.

RESULTS

A total of 16 patients (9 male, 7 female), aged between 37 and 63 years, were included in the study. The mean duration of symptoms before study recruitment was 29.24 months (range, 6-240 months). One patient elected to proceed to surgery 3 months after ATI due to reinjury at work, and 1 patient died of prostate cancer with metastases during the follow-up period. The mean final follow-up time for the remaining 15 patients was 4.51 years (range, 3.08-5.17 years). No complications were observed at the patellar tendon biopsy site for any patient. No adverse events, infection, or excessive fibroblastic reactions were observed in any patient at the injection site. Clinical evaluation revealed significant (P < .001) improvement in mean VAS pain score from 5.73 at initial assessment to 1.21 (78% improvement) at final follow-up. Mean QuickDASH, UEFS, and grip strength scores also significantly (P < .001) improved from initial assessment to final follow-up (from 45.88 to 6.61 [84%], from 31.73 to 9.20 [64%], and from 19.85 to 46.60 [208%], respectively). There was no difference in mean QuickDASH and UEFS scores at 1 year and final follow-up (P > .05); however, grip strength continued to improve (P < .001). A validated MRI scoring system indicated that the mean grade of tendinopathy at the common extensor origin improved significantly (P < .001) from initial assessment (4.31) to 1 year (2.88) and was maintained (P > .05) at final follow-up (2.87). At final follow-up, 93% of patients were either highly satisfied or satisfied with their ATI treatment.

CONCLUSION

ATI significantly improved clinical function and MRI tendinopathy scores for up to 5 years in patients with chronic resistant LE who had previously undergone unsuccessful nonsurgical treatment. This study provides evidence for the midterm durability of ATI for treatment of LE tendinopathy.

Human Fetal Progenitor Tenocytes for Regenerative Medicine

Tendon injuries are very frequent and affect a wide and heterogeneous population. Unfortunately, the healing process is long with outcomes that are not often satisfactory due to fibrotic tissue appearance, which leads to scar and adhesion development. Tissue engineering and cell therapies emerge as interesting alternatives to classical treatments. In this study, we evaluated human fetal progenitor tenocytes (hFPTs) as a potential cell source for treatment of tendon afflictions, as fetal cells are known to promote healing in a scarless regenerative process. hFPTs presented a rapid and stable growth up to passage 9, allowing to create a large cell bank for off-the-shelf availability. hFPTs showed a strong tenogenic phenotype with an excellent stability, even when placed in conditions normally inducing cells to differentiate. The karyotype also indicated a good stability up to passage 12, which is far beyond that necessary for clinical application (passage 6). When placed in coculture, hFPTs had the capacity to stimulate human adult tenocytes (hATs), which are responsible for the deposition of a new extracellular matrix during tendon healing. Finally, it was possible to distribute cells in porous or gel scaffolds with an excellent survival, thus permitting a large variety of applications (from simple injections to grafts acting as filling material). All of these results are encouraging in the development of an off-the-shelf cell source capable of stimulating tendon regeneration for the treatment of tendon injuries.

Assessment of stem cell carriers for tendon tissue engineering in pre-clinical models

Tendon injuries are prevalent and problematic, especially among young and otherwise healthy individuals. The inherently slow innate healing process combined with the inevitable scar tissue formation compromise functional recovery, imposing the need for the development of therapeutic strategies. The limited number of low activity/reparative capacity tendon-resident cells has directed substantial research efforts towards the exploration of the therapeutic potential of various stem cells in tendon injuries and pathophysiologies. Severe injuries require the use of a stem cell carrier to enable cell localisation at the defect site. The present study describes advancements that injectable carriers, tissue grafts, anisotropically orientated biomaterials, and cell-sheets have achieved in preclinical models as stem cell carriers for tendon repair.

Chiropractic treatment of lateral epicondylitis: a case report utilizing active release techniques

OBJECTIVE

The purpose of this report is to describe the chiropractic management of a case of lateral epicondylitis with active release techniques (ART).

CLINICAL FEATURES

A 48-year-old white man presented to a chiropractic clinic with a complaint of left lateral elbow pain that began 2 years previous with insidious onset. The patient reported an inability to play 18 consecutive holes of golf due to the pain.

INTERVENTION AND OUTCOME

Treatment consisted of 5 sessions of ART (a soft tissue technique that is applied to muscles, fascia, tendons, ligaments, and nerves) applied to the left elbow soft tissue over a duration of 3 weeks. The patient reported an absence of pain and ability to consistently play 18 consecutive holes of golf up to 3 times per week at 4 and 8 weeks post-treatment.

CONCLUSION

This patient with lateral epicondylitis responded favorably to chiropractic treatment using the application of ART, as demonstrated by reduced pain and increased functional outcomes.

Metabolic and cytoprotective effects of in vivo peri-patellar hyaluronic acid injections in cultured tenocytes

The purpose of this study was to investigate tenocyte mechanobiology after sudden-detraining and to examine the hypothesis that repeated peri-patellar injections of hyaluronic acid (HA) on detrained patellar tendon (PT) may reduce and limit detrained-associated damage in tenocytes. Twenty-four male Sprague-Dawley rats were divided into three groups: Untrained, Trained and Detrained. In the Detrained rats, the left tendon was untreated while the right tendon received repeated peri-patellar injections of either HA or saline (NaCl). Tenocyte morphology, metabolism and synthesis of C-terminal-propeptide of type I collagen, collagen-III, fibronectin, aggrecan, tenascin-c, interleukin-1β, matrix-metalloproteinase-1 and-3 were evaluated after 1, 3, 7 and 10 days of culture. Transmission-electronic-microscopy showed a significant increase in mitochondria and rough endoplasmic reticulum in cultured tenocytes from Detrained-HA with respect to those from Detrained-NaCl. Additionally, Detrained-HA cultures showed a significantly higher proliferation rate and viability, and increased synthesis of C-terminal-Propeptide of type I collagen, fibronectin, aggrecan, tenascin-c and matrix-metalloproteinase-3 with respect to Detrained-NaCl ones, whereas synthesis of matrix-metalloproteinase-1 and interleukin-1β was decreased. Our study demonstrates that discontinuing training activity in the short-term alters tenocyte synthetic and metabolic activity and that repeated peri-patellar infiltrations of HA during detraining allow the maintenance of tenocyte anabolic activity.

Diagnostic performance of axial-strain sonoelastography in confirming clinically diagnosed Achilles tendinopathy: comparison with B-mode ultrasound and color Doppler imaging

This primary aim of this study was to evaluate the diagnostic performance of axial-strain sonoelastography (ASE), B-mode ultrasound (US) and color Doppler US in confirming clinically symptomatic Achilles tendinopathy. The secondary aim was to establish the relationship between the strain ratio during sonoelastography and Victorian Institute of Sport Assessment-Achilles (VISA-A) scores. The VISA-A questionnaire is a validated clinical rating scale that evaluates the symptoms and dysfunction of the Achilles tendon. One hundred twenty Achilles tendons of 120 consecutively registered patients with clinical symptoms of Achilles tendinopathy and another 120 gender- and age-matched, asymptomatic Achilles tendons of 120 healthy volunteers were assessed with B-mode US, ASE and color Doppler US. Symptomatic patients had significantly higher strain ratio scores and softer Achilles tendon properties compared with controls (p < 0.001). The strain ratio was moderately correlated with VISA-A scores (r = -0.62, p < 0.001). The diagnostic accuracy of B-mode US, ASE and color Doppler US in confirming clinically symptomatic Achilles tendinopathy was 94.7%, 97.8% and 82.5% respectively. There was excellent correlation between the clinical reference standard and the grade of tendon quality on ASE (κ = 0.91, p < 0.05), compared with B-mode US (κ = 0.74, p < 0.05) and color Doppler imaging (κ = 0.49, p < 0.05). ASE is an accurate clinical tool in the evaluation of Achilles tendinopathy, with results comparable to those of B-mode US and excellent correlation with clinical findings. The strain ratio may offer promise as a supplementary tool for the objective evaluation of Achilles tendon properties.

Lipids, adiposity and tendinopathy: is there a mechanistic link? Critical review

Being overweight or obese is associated with an elevated risk of tendon pathology. However, for sportspeople the epidemiological data linking weight or adiposity on one hand, and risk of tendon pathology on the other, are less consistent. Indeed, the mechanistic links between diet, adiposity and tendon pathology remain largely unexamined. Recent studies have begun to examine the effects of dietary interventions on outcomes such as tendon biomechanics or pain. Oxidised low-density lipoprotein has been shown to (A) accumulate in the tendon tissues of mice that eat a fatty diet and (B) induce a pathological phenotype in human tendon cells. This paper addresses the current debate: is excessive body mass index (causing increased load and strain on tendon tissue) per se the underlying mechanism? Or do local or systemic influences of fat on tendons predispose to tendon pathology? This narrative review argues that excessive blood lipids may be an important avenue for clinical investigations.

Gastrocnemius shortening and heel pain

Pain and reduced function caused by disorders of either the plantar fascia or the Achilles tendon are common. Although heel pain is not a major public health problem it affects millions of people each year. For most patients, time and first-line treatments allow symptoms to resolve. A proportion of patients have resistant symptoms. Managing these recalcitrant cases is a challenge. Gastrocnemius contracture produces increased strain in both the Achilles tendon and the plantar fascia. This biomechanical feature must be properly assessed otherwise treatment is compromised.

Evaluation of digital and skinfold caliper measurements of the Achilles tendon width

Background: A critical review of the literature shows that very few objective methods for clinically evaluating Achilles tendinopathy have been described.

Aim: To evaluate the validity and reliability of common digital and skinfold calipers in measuring the Achilles tendon width.

Methods: Reliability study of ten healthy adult volunteers (five males and five females) was performed at the Rheumatology Unit of Barzilai Medical Center, Ashkelon, Israel. Achilles tendon width was measured by ultrasound at two points of both legs (the tendon attachment and 5 cm proximally). Using regular and skinfold calipers, two further measurements were made, three hours apart, at the same sites.

Results: Test-retest reliability was high for the skinfold caliper at both the upper (intraclass correlation coefficient (ICC)=0.863, p<0.001) and lower (ICC=0.931, p<0.001) points, and moderate for the regular caliper at upper (ICC=0.730, p<0.001) and lower (ICC=0.641, p<0.001) points. Moderate association was found between ultrasound and caliper measurements at the lower point (Spearman's rank correlation coefficient (rho)=0.721, p=0.019 for regular calipers; rho=0.646, p=0.043 for skinfold calipers). At the upper point, the associations were high (rho=0.778, p=0.008 for regular calipers; rho=0.960, p<0.001 for skinfold calipers).

Conclusions: The skinfold caliper showed a higher correlation with ultrasound measurements and higher intraobserver reliability than the regular caliper. Therefore, the skinfold caliper can be recommended in clinics and trials when repeated measurements need to be performed.

Outcome of calcaneoplasty in insertional achilles tendinopathy

ABSTRACT

BACKGROUND

Insertional Achilles tendinopathy may be associated with Haglund's deformity and result in chronic pain. It is usually refractory to conservative management. The aim of this study was to assess the outcome of calcaneoplasty performed in our hospital.

METHODS

Eight patients were prospectively evaluated pre- and postoperatively using the American Orthopaedic Foot and Ankle Society (AOFAS) Hindfoot Score, Visual Analogue Scale (VAS) and Short Form (SF) 36, as well as satisfaction rate. Average follow-up duration was 12.4 months.

RESULTS

The mean pre and post-operative AOFAS scores were significantly improved at three and six months. SF 36 improved in most parameters. The postoperative VAS score improved significantly and was 0 at 2 years. The procedure was rated as good to excellent by seven of the subjects.

CONCLUSION

We recommend calcaneoplasty for the treatment of insertional Achilles tendinopathy.

KEY WORDS

Calcaneoplasty, Insertional Achilles tendinopathy, Haglund's deformity.

A review on the use of cell therapy in the treatment of tendon disease and injuries

Tendon disease and injuries carry significant morbidity worldwide in both athletic and non-athletic populations. It is estimated that tendon injuries account for 30%−50% of all musculoskeletal injuries globally. Current treatments have been inadequate in providing an accelerated process of repair resulting in high relapse rates. Modern concepts in tissue engineering and regenerative medicine have led to increasing interest in the application of cell therapy for the treatment of tendon disease. This review will explore the use of cell therapy, by bringing together up-to-date evidence from in vivo human and animal studies, and discuss the issues surrounding the safety and efficacy of its use in the treatment of tendon disease.

Prevalence of Achilles and patellar tendinopathy and their association to intratendinous changes in adolescent athletes

Achilles (AT) and patellar tendons (PT) are commonly affected by tendinopathy in adult athletes but prevalence of symptoms and morphological changes in adolescents is unclear. The study aimed to determine prevalence of tendinopathy and intratendinous changes in ATs and PTs of adolescent athletes. A total of 760 adolescent athletes (13.0 ± 1.9 years; 160 ± 13 cm; 50 ± 14 kg) were examined. History, local clinical examination, and longitudinal Doppler ultrasound analysis for both ATs and PTs were performed including identification of intratendinous echoic changes and vascularization. Diagnosis of tendinopathy was complied clinically in case of positive history of tendon pain and tendon pain on palpation. Achilles tendinopathy was diagnosed in 1.8% and patellar tendinopathy in 5.8%. Vascularizations were visible in 3.0% of ATs and 11.4% of PTs, hypoechogenicities in 0.7% and 3.2% as well as hyperechogenicities in 0% and 0.3%, respectively. Vascularizations and hypoechogenicities were statistically significantly more often in males than in females (P ≤ 0.02). Subjects with patellar tendinopathy had higher prevalence of structural intratendinous changes than those without PT symptoms (P ≤ 0.001). In adolescent athletes, patellar tendinopathy is three times more frequent compared with Achilles tendinopathy. Longitudinal studies are necessary to investigate physiological or pathological origin of vascularizations and its predictive value in development of tendinopathy.

Non-uniform displacements within the Achilles tendon observed during passive and eccentric loading

The goal of this study was to investigate Achilles tendon tissue displacement patterns under passive and eccentric loading conditions. Nine healthy young adults were positioned prone on an examination table with their foot secured to a rotating footplate aligned with the ankle. Subjects cyclically rotated their ankle over a 25° range of motion at 0.5 Hz. An inertial load geared to the footplate induced eccentric plantarflexor contractions with dorsiflexion. Passive cyclic ankle motion was also performed over the same angular range of motion. An ultrasound transducer positioned over the distal Achilles tendon was used to collect radiofrequency (RF) images at 70 frames/s. Two-dimensional ultrasound elastographic analysis of the RF data was used to track tendon tissue displacements throughout the cyclic motion. Non-uniform tissue displacement patterns were observed in all trials, with the deeper portions of the Achilles tendon consistently exhibiting larger displacements than the superficial tendon (average of 0.9-2.6mm larger). Relative to the passive condition, eccentric loading consistently induced smaller tissue displacements in all tendon regions, except for the superficial tendon in a flexed knee posture. Significantly greater overall tissue displacement was observed in a more extended knee posture (30°) relative to a flexed knee posture (90°). These spatial- and posture-dependent displacement patterns suggest that the tendon undergoes non-uniform deformation under in vivo loading conditions. Such behavior could reflect relative sliding between the distinct tendon fascicles that arise from the gastrocnemius and soleus muscles.

Platelet-rich therapies for musculoskeletal soft tissue injuries

BACKGROUND

Platelet-rich therapies are being used increasingly in the treatment of musculoskeletal soft tissue injuries such as ligament, muscle and tendon tears and tendinopathies. These therapies can be used as the principal treatment or as an augmentation procedure (application after surgical repair or reconstruction). Platelet-rich therapies are produced by centrifuging a quantity of the patient's own blood and extracting the active, platelet-rich, fraction. The platelet-rich fraction is applied to the injured tissue; for example, by injection. Platelets have the ability to produce several growth factors, so these therapies should enhance tissue healing. There is a need to assess whether this translates into clinical benefit.

OBJECTIVES

To assess the effects (benefits and harms) of platelet-rich therapies for treating musculoskeletal soft tissue injuries.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (25 March 2013), the Cochrane Central Register of Controlled Trials (CENTRAL 2013 Issue 2), MEDLINE (1946 to March 2013), EMBASE (1980 to 2013 Week 12) and LILACS (1982 to March 2012). We also searched trial registers (to Week 2 2013) and conference abstracts (2005 to March 2012). No language or publication restrictions were applied.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials that compared platelet-rich therapy with either placebo, autologous whole blood, dry needling or no platelet-rich therapy for people with acute or chronic musculoskeletal soft tissue injuries. Primary outcomes were functional status, pain and adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed each study's risk of bias. Disagreement was resolved by discussion or by arbitration by a third author. We contacted trial authors for clarification of methods or missing data. Treatment effects were assessed using risk ratios for dichotomous data and mean differences (MD) or standardised mean differences (SMD) for continuous data, together with 95% confidence intervals. Where appropriate, data were pooled using the fixed-effect model for RR and MD, and the random-effects model for SMD. The quality of the evidence for each outcome was assessed using GRADE criteria.

MAIN RESULTS

We included data from 19 small single centre trials (17 randomised and two quasi-randomised; 1088 participants) that compared platelet-rich therapy with placebo, autologous whole blood, dry needling or no platelet-rich therapy. These trials covered eight clinical conditions: rotator cuff tears (arthroscopic repair) (six trials); shoulder impingement syndrome surgery (one trial); elbow epicondylitis (three trials); anterior cruciate ligament (ACL) reconstruction (four trials), ACL reconstruction (donor graft site application) (two trials), patellar tendinopathy (one trial), Achilles tendinopathy (one trial) and acute Achilles rupture surgical repair (one trial). We also grouped trials into 'tendinopathies' where platelet-rich therapy (PRT) injections were the main treatment (five trials), and surgical augmentation procedures where PRT was applied during surgery (14 trials). Trial participants were mainly male, except in trials including rotator cuff tears, and elbow and Achilles tendinopathies.Three trials were judged as being at low risk of bias; the other 16 were at high or unclear risk of bias relating to selection, detection, attrition or selective reporting, or combinations of these. The methods of preparing platelet-rich plasma (PRP) varied and lacked standardisation and quantification of the PRP applied to the patient.We were able to pool data for our primary outcomes (function, pain, adverse events) for a maximum of 11 trials and 45% of participants. The evidence for all primary outcomes was judged as being of very low quality.Data assessing function in the short term (up to three months) were pooled from four trials that assessed PRT in three clinical conditions and used four different measures. These showed no significant difference between PRT and control (SMD 0.26; 95% confidence interval (CI) -0.19 to 0.71; P value 0.26; I² = 51%; 162 participants; positive values favour PRT). Medium-term function data (at six months) were pooled from five trials that assessed PRT in five clinical conditions and used five different measures. These also showed no difference between groups (SMD -0.09, 95% CI -0.56 to 0.39; P value 0.72; I² = 50%; 151 participants). Long-term function data (at one year) were pooled from 10 trials that assessed PRT in five clinical conditions and used six different measures. These also showed no difference between groups (SMD 0.25, 95% CI -0.07 to 0.57; P value 0.12; I² = 66%; 484 participants). Although the 95% confidence intervals indicate the possibility of a poorer outcome in the PRT group up to a moderate difference in favour of PRT at short- and long-term follow-up, these do not translate into clinically relevant differences.Data pooled from four trials that assessed PRT in three clinical conditions showed a small reduction in short-term pain in favour of PRT on a 10-point scale (MD -0.95, 95% CI -1.41 to -0.48; I² = 0%; 175 participants). The clinical significance of this result is marginal.Four trials reported adverse events; another seven trials reported an absence of adverse events. There was no difference between treatment groups in the numbers of participants with adverse effects (7/241 versus 5/245; RR 1.31, 95% CI 0.48 to 3.59; I² = 0%; 486 participants).In terms of individual conditions, we pooled heterogeneous data for long-term function from six trials of PRT application during rotator cuff tear surgery. This showed no statistically or clinically significant differences between the two groups (324 participants).The available evidence is insufficient to indicate whether the effects of PRT will differ importantly in individual clinical conditions.

AUTHORS' CONCLUSIONS

Overall, and for the individual clinical conditions, there is currently insufficient evidence to support the use of PRT for treating musculoskeletal soft tissue injuries. Researchers contemplating RCTs should consider the coverage of currently ongoing trials when assessing the need for future RCTs on specific conditions. There is need for standardisation of PRP preparation methods.

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

BACKGROUND

Chronic patellar tendinopathy (PT) is one of the most common overuse knee disorders. Platelet-rich plasma (PRP) appears to be a reliable nonoperative therapy for chronic PT.

PURPOSE

To evaluate clinical and radiological outcomes of 3 consecutive ultrasound (US)-guided PRP injections for the treatment of chronic PT in athletes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 28 athletes (17 professional, 11 semiprofessional) with chronic PT refractory to nonoperative management were prospectively included for US-guided pure PRP injections into the site of the tendinopathy. The same treating physician at a single institution performed 3 consecutive injections 1 week apart, with the same PRP preparation used. All patients underwent clinical evaluation, including the Victorian Institute of Sport Assessment-Patella (VISA-P) score, visual analog scales (VAS) for pain, and Lysholm knee scale before surgery and after return to practice sports. Tendon healing was assessed with MRI at 1 and 3 months after the procedure.

RESULTS

The VISA-P, VAS, and Lysholm scores all significantly improved at the 2-year follow-up. The average preprocedure VISA-P, VAS, and Lysholm scores improved from 39 to 94 (P < .001), 7 to 0.8 (P < .0001), and 60 to 96 (P < .001), respectively, at the 2-year follow-up. Twenty-one of the 28 athletes returned to their presymptom sporting level at 3 months (range, 2-6 months) after the procedure. Follow-up MRI assessment showed improved structural integrity of the tendon at 3 months after the procedure and complete return to normal structural integrity of the tendon in 16 patients (57%). Seven patients did not recover their presymptom sporting level (among them, 6 were considered treatment failures): 3 patients returned to sport at a lesser level, 1 patient changed his sport activity (for other reasons), and 3 needed surgical intervention.

CONCLUSION

In this study, application of 3 consecutive US-guided PRP injections significantly improved symptoms and function in athletes with chronic PT and allowed fast recovery to their presymptom sporting level. The PRP treatment permitted a return to a normal architecture of the tendon as assessed by MRI.

Humeral lateral epicondylitis complicated by hydroxyapatite dihydrite deposition disease: a case report

OBJECTIVE

The aim of this case report is to differentiate the recovery timeline expected for patients with simple lateral epicondylitis from an abnormal recovery period, in which case an underlying condition should be suspected.

CLINICAL FEATURES

A 49-year-old woman presented to a chiropractic clinic with posterolateral right elbow pain. The history included chronic recurrent lateral elbow pain, followed by a traumatic event leading to sustained pain and disability.

INTERVENTION AND OUTCOMES

Following a trial of conservative therapy including activity restrictions, soft tissue therapy, joint mobilizations, and therapeutic ultrasonography that led to no significant improvement, the patient was referred for diagnostic imaging that revealed hydroxyapatite dihydrite deposition disease.

CONCLUSION

This report describes a case for which lateral epicondylitis symptoms failed to resolve because of an underlying condition (hydroxyapatite dihydrite deposition disease). This case emphasizes that primary care practitioners treating lateral epicondylitis should consider referral for further investigations when positive results are not achieved.

Strong evidence against platelet-rich plasma injections for chronic lateral epicondylar tendinopathy: a systematic review

BACKGROUND

Chronic lateral epicondylar tendinopathy is frequent in athletes, and platelet-rich plasma (PRP) is being used increasingly in its treatment.

OBJECTIVE

To systematically review the literature on the efficacy of PRP injections for chronic lateral epicondylar tendinopathy.

METHODS

The databases of PubMed, EMBASE, CINAHL, Medline OvidSP, Scopus, Google Scholar, Web of Science and Cochrane Library were searched in October 2013. Inclusion criteria were a clinical diagnosis of chronic lateral epicondylar tendinopathy, a randomised controlled trial, an intervention with a PRP injection and the outcome measures described in terms of pain and/or function. One author screened the search results and two authors independently assessed the study quality using the Physiotherapy Evidence Database (PEDro) score. A study was considered to be of high quality if its PEDro score was ≥6. A best evidence synthesis was used to identify the level of evidence.

RESULTS

6 studies were included, of which four were considered to be of high quality. Three high-quality studies (75%) and two low-quality studies showed no significant benefit at the final follow-up measurement or predefined primary outcome score when compared with a control group. One high-quality study (25%) showed a beneficial effect of a PRP injection when compared with a corticosteroid injection (corticosteroid injections are harmful in tendinopathy). Based on the best evidence synthesis, there is strong evidence that PRP injections are not efficacious in chronic lateral epicondylar tendinopathy.

CONCLUSIONS

There is strong evidence that PRP injections are not efficacious in the management of chronic lateral elbow tendinopathy.

Comparison of the effect of intra-tendon applications of recombinant human platelet-derived growth factor-BB, platelet-rich plasma, steroids in a rat achilles tendon collagenase model

This study compared the effect of intra-tendon (IT) delivery of recombinant human platelet-derived growth factor-BB (rhPDGF-BB), platelet-rich plasma (PRP) and corticosteroids in a rat tendinopathy model. Seven days after collagenase induction of tendinopathy, a 30-µl IT injection was administered. Treatments included: saline; 3 µg rhPDGF-BB; 10 µg rhPDGF-BB; PRP; and 300 µg triamcinolone acetonide (TCA). Outcomes were assessed 7 and 21 days after treatment. All groups exhibited good to excellent repair. Relative to saline, cell proliferation increased 65% in the 10 µg rhPDGF-BB group and decreased 74% in the TCA group; inflammation decreased 65% in the TCA group. At 7 days, maximum load-to-failure was increased in the 3 µg rhPDGF-BB group relative to saline, PRP, and TCA (p < 0.025). On day 21, maximum load-to-rupture was increased in the 10 µg rhPDGF-BB group relative to saline, PRP, and TCA (p < 0.035) and in the 3 µg rhPDGF-BB group compared to saline and TCA (p < 0.027). Stiffness in the 10 µg rhPDGF-BB group was increased compared to saline, PRP, and TCA (p < 0.038). Histology demonstrated similar repair in all groups. PRP and TCA did not improve mechanical properties compared to saline. Injections of rhPDGF-BB increased maximum load-to-failure (3 and 10 µg) and stiffness (10 µg) relative to controls and commonly used treatments. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:145-150, 2014.

Platelet-rich therapies for musculoskeletal soft tissue injuries

BACKGROUND

Platelet-rich therapies are being used increasingly in the treatment of musculoskeletal soft tissue injuries such as ligament, muscle and tendon tears and tendinopathies. These therapies can be used as the principal treatment or as an augmentation procedure (application after surgical repair or reconstruction). Platelet-rich therapies are produced by centrifuging a quantity of the patient's own blood and extracting the active, platelet-rich, fraction. The platelet-rich fraction is applied to the injured tissue; for example, by injection. Platelets have the ability to produce several growth factors, so these therapies should enhance tissue healing. There is a need to assess whether this translates into clinical benefit.

OBJECTIVES

To assess the effects (benefits and harms) of platelet-rich therapies for treating musculoskeletal soft tissue injuries.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (25 March 2013), the Cochrane Central Register of Controlled Trials (CENTRAL 2013 Issue 2), MEDLINE (1946 to March 2013), EMBASE (1980 to 2013 Week 12) and LILACS (1982 to March 2012). We also searched trial registers (to Week 2 2013) and conference abstracts (2005 to March 2012). No language or publication restrictions were applied.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials that compared platelet-rich therapy with either placebo, autologous whole blood, dry needling or no platelet-rich therapy for people with acute or chronic musculoskeletal soft tissue injuries. Primary outcomes were functional status, pain and adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed each study's risk of bias. Disagreement was resolved by discussion or by arbitration by a third author. We contacted trial authors for clarification of methods or missing data. Treatment effects were assessed using risk ratios for dichotomous data and mean differences (MD) or standardised mean differences (SMD) for continuous data, together with 95% confidence intervals. Where appropriate, data were pooled using the fixed-effect model for RR and MD, and the random-effects model for SMD. The quality of the evidence for each outcome was assessed using GRADE criteria.

MAIN RESULTS

We included data from 19 small single centre trials (17 randomised and two quasi-randomised; 1088 participants) that compared platelet-rich therapy with placebo, autologous whole blood, dry needling or no platelet-rich therapy. These trials covered eight clinical conditions: rotator cuff tears (arthroscopic repair) (six trials); shoulder impingement syndrome surgery (one trial); elbow epicondylitis (three trials); anterior cruciate ligament (ACL) reconstruction (four trials), ACL reconstruction (donor graft site application) (two trials), patellar tendinopathy (one trial), Achilles tendinopathy (one trial) and acute Achilles rupture surgical repair (one trial). We also grouped trials into 'tendinopathies' where platelet-rich therapy (PRT) injections were the main treatment (five trials), and surgical augmentation procedures where PRT was applied during surgery (14 trials). Trial participants were mainly male, except in trials including rotator cuff tears, and elbow and Achilles tendinopathies.Three trials were judged as being at low risk of bias; the other 16 were at high or unclear risk of bias relating to selection, detection, attrition or selective reporting, or combinations of these. The methods of preparing platelet-rich plasma (PRP) varied and lacked standardisation and quantification of the PRP applied to the patient.We were able to pool data for our primary outcomes (function, pain, adverse events) for a maximum of 11 trials and 45% of participants. The evidence for all primary outcomes was judged as being of very low quality.Data assessing function in the short term (up to three months) were pooled from five trials that assessed PRT in three clinical conditions and used four different measures. These showed no significant difference between PRT and control (SMD 0.24; 95% confidence interval (CI) -0.07 to 0.56; P value 0.13; I² = 35%; 273 participants; positive values favour PRT). Medium-term function data (at six months) were pooled from six trials that assessed PRT in five clinical conditions and used six different measures. These also showed no difference between groups (SMD 0.06; 95% CI -0.39 to 0.51; P value 0.79; I² = 64%; 262 participants). Long-term function data (at one year) were pooled from 10 trials that assessed PRT in five clinical conditions and used six different measures. These also showed no difference between groups (SMD 0.25, 95% CI -0.07 to 0.57; P value 0.12; I² = 66%; 484 participants). Although the 95% confidence intervals indicate the possibility of a slightly poorer outcome in the PRT group up to a moderate difference in favour of PRT at short- and long-term follow-up, these do not translate into clinically relevant differences.Data pooled from four trials that assessed PRT in three clinical conditions showed a small reduction in short-term pain in favour of PRT on a 10-point scale (MD -0.95, 95% CI -1.41 to -0.48; I² = 0%; 175 participants). The clinical significance of this result is marginal.Four trials reported adverse events; another seven trials reported an absence of adverse events. There was no difference between treatment groups in the numbers of participants with adverse effects (7/241 versus 5/245; RR 1.31, 95% CI 0.48 to 3.59; I² = 0%; 486 participants).In terms of individual conditions, we pooled heterogeneous data for long-term function from six trials of PRT application during rotator cuff tear surgery. This showed no statistically or clinically significant differences between the two groups (324 participants). Pooled data for short-term function for three elbow epicondylitis trials (179 participants) showed a statistically significant difference in favour of PRT, but the clinical significance of this finding is uncertain.The available evidence is insufficient to indicate whether the effects of PRT will differ importantly in individual clinical conditions.

AUTHORS' CONCLUSIONS

Overall, and for the individual clinical conditions, there is currently insufficient evidence to support the use of PRT for treating musculoskeletal soft tissue injuries. Researchers contemplating RCTs should consider the coverage of currently ongoing trials when assessing the need for future RCTs on specific conditions. There is need for standardisation of PRP preparation methods.

Radiologic morphology of the calcaneus: a study of radiologic angles in a pediatric population

BACKGROUND

The Fowler-Philip, calcaneal pitch, and total calcaneal angles define the radiologic morphology of the rearfoot. We studied these angles in healthy adolescents.

METHODS

We studied 141 feet. Patients with inflammatory or traumatic injuries were excluded. The mean participant age was 11.5 years. The Fowler-Philip, calcaneal pitch, and total calcaneal angles were measured on lateral weightbearing radiographs. The statistics included descriptive, sample size (α=0.05 and β=0.20), the Student t test, and analysis of variance; P < .05 was considered significant.

RESULTS

The samples were 141 and 35 radiographs for the Fowler-Philip and calcaneal pitch angles, respectively. Ninety percent, 25.1%, and 97.4% of the adolescents had normal Fowler-Philip, calcaneal pitch, and total calcaneal angles, respectively. In addition, 9.9%, 74.9%, and 2.6% of the values were outside the reference ranges, respectively. The Fowler-Philip angle decreased and the calcaneal pitch angle increased significantly with age (P = .0005). The total calcaneal angle did not change with age (P = .65).

CONCLUSIONS

The mean angle values in a pediatric population did not differ from those in adults. We found a high percentage of calcaneal pitch angles outside the reference range. Age influenced the Fowler-Philip and calcaneal pitch angles but not the total calcaneal angle.