Eccentric training of the gastrocnemius-soleus complex in chronic Achilles tendinopathy results in decreased tendon volume and intratendinous signal as evaluated by MRI

The current status of various preclinical therapeutic approaches for tendon repair

Tendons are fibroblastic structures that link muscle and bone. There are two kinds of tendon injuries, including acute and chronic. Each form of injury or deterioration can result in significant pain and loss of tendon function. The recovery of tendon damage is a complex and time-consuming recovery process. Depending on the anatomical location of the tendon tissue, the clinical outcomes are not the same. The healing of the wound process is divided into three stages that overlap: inflammation, proliferation, and tissue remodeling. Furthermore, the curing tendon has a high re-tear rate. Faced with the challenges, tendon injury management is still a clinical issue that must be resolved as soon as possible. Several newer directions and breakthroughs in tendon recovery have emerged in recent years. This article describes tendon injury and summarizes recent advances in tendon recovery, along with stem cell therapy, gene therapy, Platelet-rich plasma remedy, growth factors, drug treatment, and tissue engineering. Despite the recent fast-growing research in tendon recovery treatment, still, none of them translated to the clinical setting. This review provides a detailed overview of tendon injuries and potential preclinical approaches for treating tendon injuries.

Patellar tendon biomechanical and morphologic properties and their relationship to serum clinical variables in persons with prediabetes and type 2 diabetes

Tendon biomechanical properties and fibril organization are altered in patients with diabetes compared to healthy individuals, yet few biomarkers have been associated with in vivo tendon properties. We investigated the relationships between in vivo imaging-based tendon properties, serum variables, and patient characteristics across healthy controls (n = 14, age: 45 ± 5 years, body mass index [BMI]: 24 ± 1, hemoglobin A1c [HbA1c]: 5.3 ± 0.1%), prediabetes (n = 14, age: 54 ± 5 years, BMI: 29 ± 2; HbA1c: 5.7 ± 0.1), and type 2 diabetes (n = 13, age: 55 ± 3 years, BMI: 33 ± 2, HbA1c: 6.7 ± 0.3). We used ultrasound speckle-tracking and measurements from magnetic resonance imaging (MRI) to estimate the patellar tendon in vivo tangent modulus. Analysis of plasma c-peptide, interleukin-1β (IL-1β), IL-6, IL-8, tumor necrosis factor-α (TNF-α), adiponectin, leptin, insulin-like growth factor 1 (IGF-1), and C-reactive protein (CRP) was completed. We built regression models incorporating statistically significant covariates and indicators for the clinically defined groups. We found that tendon cross-sectional area normalized to body weight (BWN CSA) and modulus were lower in patients with type 2 diabetes than in healthy controls (p < 0.05). Our regression analysis revealed that a model that included BMI, leptin, high-density lipoprotein (HDL), low-density lipoprotein (LDL), age, and group explained ~70% of the variability in BWN CSA (R2  = 0.70, p < 0.001). For modulus, including the main effects LDL, groups, HbA1c, age, BMI, cholesterol, IGF-1, c-peptide, leptin, and IL-6, accounted for ~54% of the variability in modulus (R2  = 0.54, p < 0.05). While BWN CSA and modulus were lower in those with diabetes, group was a poor predicter of tendon properties when considering the selected covariates. These data highlight the multifactorial nature of tendon changes with diabetes and suggest that blood variables could be reliable predictors of tendon properties.

Exercise therapy for tendinopathy: a mixed-methods evidence synthesis exploring feasibility, acceptability and effectiveness

Background

Tendinopathy is a common, painful and functionally limiting condition, primarily managed conservatively using exercise therapy.

Review questions

(i) What exercise interventions have been reported in the literature for which tendinopathies? (ii) What outcomes have been reported in studies investigating exercise interventions for tendinopathy? (iii) Which exercise interventions are most effective across all tendinopathies? (iv) Does type/location of tendinopathy or other specific covariates affect which are the most effective exercise therapies? (v) How feasible and acceptable are exercise interventions for tendinopathies?

Methods

A scoping review mapped exercise interventions for tendinopathies and outcomes reported to date (questions i and ii). Thereafter, two contingent systematic review workstreams were conducted. The first investigated a large number of studies and was split into three efficacy reviews that quantified and compared efficacy across different interventions (question iii), and investigated the influence of a range of potential moderators (question iv). The second was a convergent segregated mixed-method review (question v). Searches for studies published from 1998 were conducted in library databases (n = 9), trial registries (n = 6), grey literature databases (n = 5) and Google Scholar. Scoping review searches were completed on 28 April 2020 with efficacy and mixed-method search updates conducted on 19 January 2021 and 29 March 2021.

Results

Scoping review - 555 included studies identified a range of exercise interventions and outcomes across a range of tendinopathies, most commonly Achilles, patellar, lateral elbow and rotator cuff-related shoulder pain. Strengthening exercise was most common, with flexibility exercise used primarily in the upper limb. Disability was the most common outcome measured in Achilles, patellar and rotator cuff-related shoulder pain; physical function capacity was most common in lateral elbow tendinopathy. Efficacy reviews - 204 studies provided evidence that exercise therapy is safe and beneficial, and that patients are generally satisfied with treatment outcome and perceive the improvement to be substantial. In the context of generally low and very low-quality evidence, results identified that: (1) the shoulder may benefit more from flexibility (effect sizeResistance:Flexibility = 0.18 [95% CrI 0.07 to 0.29]) and proprioception (effect sizeResistance:Proprioception = 0.16 [95% CrI -1.8 to 0.32]); (2) when performing strengthening exercise it may be most beneficial to combine concentric and eccentric modes (effect sizeEccentricOnly:Concentric+Eccentric = 0.48 [95% CrI -0.13 to 1.1]; and (3) exercise may be most beneficial when combined with another conservative modality (e.g. injection or electro-therapy increasing effect size by ≈0.1 to 0.3). Mixed-method review - 94 studies (11 qualitative) provided evidence that exercise interventions for tendinopathy can largely be considered feasible and acceptable, and that several important factors should be considered when prescribing exercise for tendinopathy, including an awareness of potential barriers to and facilitators of engaging with exercise, patients' and providers' prior experience and beliefs, and the importance of patient education, self-management and the patient-healthcare professional relationship.

Limitations

Despite a large body of literature on exercise for tendinopathy, there are methodological and reporting limitations that influenced the recommendations that could be made.

Conclusion

The findings provide some support for the use of exercise combined with another conservative modality; flexibility and proprioception exercise for the shoulder; and a combination of eccentric and concentric strengthening exercise across tendinopathies. However, the findings must be interpreted within the context of the quality of the available evidence.

Future work

There is an urgent need for high-quality efficacy, effectiveness, cost-effectiveness and qualitative research that is adequately reported, using common terminology, definitions and outcomes.

Study registration

This project is registered as DOI: 10.11124/JBIES-20-00175 (scoping review); PROSPERO CRD 42020168187 (efficacy reviews); https://osf.io/preprints/sportrxiv/y7sk6/ (efficacy review 1); https://osf.io/preprints/sportrxiv/eyxgk/ (efficacy review 2); https://osf.io/preprints/sportrxiv/mx5pv/ (efficacy review 3); PROSPERO CRD42020164641 (mixed-method review).

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) HTA programme and will be published in full in HTA Journal; Vol. 27, No. 24. See the NIHR Journals Library website for further project information.

Identifying characteristics of resistance-based therapeutic exercise interventions for Achilles tendinopathy: A scoping review

OBJECTIVE

This scoping review describes resistance-based therapeutic exercise intervention characteristics for Achilles tendinopathy (AT) treatment (e.g., therapeutic dose, underlying mechanisms targeted by exercise) and assesses participant reporting characteristics.

METHODS

Seven electronic databases were searched; studies delivering a resistance exercise-focused treatment for individuals with AT were included. The Template for Intervention Description and Replication (TIDieR) and the ICON 2019 'Recommended standards for reporting participant characteristics in tendinopathy research' checklists framed data extraction, and study quality was assessed using the Mixed Methods Appraisal Tool 2018 version.

RESULTS

68 publications (describing 59 studies and 72 exercise programs) were included. Results demonstrate that therapeutic exercise interventions for AT are well reported according to the TIDieR checklist, and participant characteristics are well reported according to the ICON checklist. Various underlying therapeutic mechanisms were proposed, with the most common being increasing tendon strength, increasing calf muscle strength, and enhancing collagen synthesis.

CONCLUSIONS

While evidence suggests that resistance-based therapeutic exercise interventions are effective in treating AT, more reporting on program fidelity, adherence, and compliance is needed. By summarizing currently published AT exercise programs and reporting key intervention characteristics in a single location, this review can assist clinicians in developing individualized resistance training programs for people with AT.

Exercise for rotator cuff tendinopathy: Proposed mechanisms of recovery

Rotator cuff (RC) tendinopathy is a common recurrent cause of shoulder pain, and resistance exercise is the first-line recommended intervention. Proposed causal mechanisms of resistance exercise for patients with RC tendinopathy consist of four domains: tendon structure, neuromuscular factors, pain and sensorimotor processing, and psychosocial factors. Tendon structure plays a role in RC tendinopathy, with decreased stiffness, increased thickness, and collagen disorganization. Neuromuscular performance deficits of altered kinematics, muscle activation, and force are present in RC tendinopathy, but advanced methods of assessing muscle performance are needed to fully assess these factors. Psychological factors of depression, anxiety, pain catastrophizing, treatment expectations, and self-efficacy are present and predict patient-reported outcomes. Central nervous system dysfunctions also exist, specifically altered pain and sensorimotor processing. Resisted exercise may normalize these factors, but limited evidence exists to explain the relationship of the four proposed domains to trajectory of recovery and defining persistent deficits limiting outcomes. Clinicians and researchers can use this model to understand how exercise mediates change in patient outcomes, develop subgroups to deliver patient-specific approach for treatment and define metrics to track recovery over time. Supporting evidence is limited, indicating the need for future studies characterizing mechanisms of recovery with exercise for RC tendinopathy.

Foundational Principles and Adaptation of the Healthy and Pathological Achilles Tendon in Response to Resistance Exercise: A Narrative Review and Clinical Implications

Therapeutic exercise is widely considered a first line fundamental treatment option for managing tendinopathies. As the Achilles tendon is critical for locomotion, chronic Achilles tendinopathy can have a substantial impact on an individual's ability to work and on their participation in physical activity or sport and overall quality of life. The recalcitrant nature of Achilles tendinopathy coupled with substantial variation in clinician-prescribed therapeutic exercises may contribute to suboptimal outcomes. Further, loading the Achilles tendon with sufficiently high loads to elicit positive tendon adaptation (and therefore promote symptom alleviation) is challenging, and few works have explored tissue loading optimization for individuals with tendinopathy. The mechanism of therapeutic benefit that exercise therapy exerts on Achilles tendinopathy is also a subject of ongoing debate. Resultingly, many factors that may contribute to an optimal therapeutic exercise protocol for Achilles tendinopathy are not well described. The aim of this narrative review is to explore the principles of tendon remodeling under resistance-based exercise in both healthy and pathologic tissues, and to review the biomechanical principles of Achilles tendon loading mechanics which may impact an optimized therapeutic exercise prescription for Achilles tendinopathy.

Resistance Training Interventions for Lower Limb Tendinopathies: A Scoping Review of Resistance Training Reporting Content, Quality, and Scientific Implementation

The objectives of this scoping review were as follows: (1) to describe what exercises and intervention variables are used in resistance training interventions for lower limb tendinopathy,  (2) to assess the completeness of reporting as assessed by the Consensus on Exercise Reporting Template (CERT) and the Toigo and Boutellier framework, and (3) to assess the implementation of scientific resistance training principles. We searched MEDLINE, CINAHL, AMED, Embase, SPORTDiscus, and Cochrane Library databases. Randomized controlled trials, cohort studies, case series, case reports, and observational studies that reported using resistance exercises for lower limb tendinopathies were considered for inclusion, with 194 studies meeting the inclusion criteria. Completeness of the reporting of exercise descriptors and programme variables was assessed by the CERT and the Toigo and Boutellier framework. Reporting of exercise descriptor items from the Toigo and Boutellier framework ranged from 0 to 13, with an average score of 9/13, with only 9 studies achieving a full 13/13. Reporting of items from the CERT ranged from 0 to 18, with an average score of 13/19. No study achieved a full 19/19; however, 8 achieved 18/19. Scoring for resistance training principles ranged from 1 to 10, with only 14 studies achieving 10/10. Eccentric heel-drops were the most common exercise (75 studies), followed by isotonic heel raises (38), and single-leg eccentric decline squats (27). The reporting of exercise descriptors and intervention content was high across studies, with most allowing exercise replication, particularly for Achilles and patellar tendinopathy. However, reporting for some tendinopathies and content items such as adherence was poor, limiting optimal translation to clinical practice.

ICON 2020-International Scientific Tendinopathy Symposium Consensus: A Systematic Review of Outcome Measures Reported in Clinical Trials of Achilles Tendinopathy

BACKGROUND

Nine core domains for tendinopathy have been identified. For Achilles tendinopathy there is large variation in outcome measures used, and how these fit into the core domains has not been investigated.

OBJECTIVE

To identify all available outcome measures outcome measures used to assess the clinical phenotype of Achilles tendinopathy in prospective studies and to map the outcomes measures into predefined health-related core domains.

DESIGN

Systematic review.

DATA SOURCES

Embase, MEDLINE (Ovid), Web of Science, CINAHL, The Cochrane Library, SPORTDiscus and Google Scholar.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Clinical diagnosis of Achilles tendinopathy, sample size ≥ ten participants, age ≥ 16 years, and the study design was a randomized or non-randomized clinical trial, observational cohort, single-arm intervention, or case series.

RESULTS

9376 studies were initially screened and 307 studies were finally included, totaling 13,248 participants. There were 233 (177 core domain) different outcome measures identified across all domains. For each core domain outcome measures were identified, with a range between 8 and 35 unique outcome measures utilized for each domain. The proportion of studies that included outcomes for predefined core domains ranged from 4% for the psychological factors domain to 72% for the disability domain.

CONCLUSION

233 unique outcome measures for Achilles tendinopathy were identified. Most frequently, outcome measures were used within the disability domain. Outcome measures assessing psychological factors were scarcely used. The next step in developing a core outcome set for Achilles tendinopathy is to engage patients, clinicians and researchers to reach consensus on key outcomes measures.

PROSPERO REGISTRATION

CRD42020156763.

Beyond the Diagnosis: Using Patient Characteristics and Domains of Tendon Health to Identify Latent Subgroups of Achilles Tendinopathy

OBJECTIVE

To identify latent subgroups among patients with Achilles tendinopathy, describe patient characteristics and clinical attributes that defined each subgroup, and develop a clinical classification model for subgroup membership.

DESIGN

Cross-sectional study.

METHODS

One hundred forty-five participants (men, n = 73; mean ± SD age, 51 ± 14 years) with clinically diagnosed Achilles tendinopathy completed a baseline evaluation, including demographics and medical history, patient-reported outcome measures, a clinical exam, tendon structure measures via ultrasound imaging and continuous shear-wave elastography, and a functional test battery. Subgroups were identified using mixture modeling. We compared the subgroups using a 1-way analysis-of-variance or chi-square test and the Tukey post hoc test to identify defining attributes. We developed a clinical classification model using logistic regression and receiver operating characteristic curves.

RESULTS

Three latent subgroups were identified and named by their distinctive patient characteristics and clinical attributes. The activity-dominant subgroup (n = 67), on average, had the highest physical activity level, function, and quality of life; reported mild symptoms; and was the youngest. The psychosocial-dominant subgroup (n = 56), on average, had the worst symptoms, impaired function, heightened psychological factors, the poorest quality of life, minimal tendon structural alterations, and was obese and predominantly female. The structure-dominant subgroup (n = 22), on average, had the most tendon structural alterations, severe functional deficits, moderate symptoms and psychological factors, reduced quality of life, and was the oldest, obese, and predominantly male. The clinical classification model correctly classified 85% (123/145) of participants.

CONCLUSION

Three Achilles tendinopathy subgroups (activity dominant, psychosocial dominant, and structure dominant) differed in patient characteristics and clinical attributes. J Orthop Sports Phys Ther 2021;51(9):440-448. Epub 1 Jun 2021. doi:10.2519/jospt.2021.10271.

Multimodal Ultrasound Versus MRI for the Diagnosis and Monitoring of Achilles Tendinopathy: A Prospective Longitudinal Study

Background:

The diagnosis and monitoring of Achilles tendinopathy with imaging are challenging. There is a lack of studies comparing the diagnostic accuracy of magnetic resonance imaging (MRI), brightness mode ultrasound (B-mode), and power Doppler ultrasound with recent technologies such as ultrasound tissue characterization (UTC) and shear wave elastography (SWE).

Purpose:

To assess whether SWE and UTC, which offer quantitative values, show a superior diagnostic accuracy and capacity to detect structural improvement in Achilles tendinopathy compared with MRI, B-mode, or power Doppler.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

Patients with insertional (n = 28) and midportion (n = 38) Achilles tendinopathy were evaluated at baseline and 6-month follow-up using MRI, B-mode, power Doppler, SWE, and UTC. Asymptomatic controls (n = 37) were evaluated at T₀. Diagnostic accuracy was analyzed based on a quantitative receiver operating characteristic (ROC) analysis with quantitative cutoff values (anteroposterior diameter, Öhberg score, UTC echo type, Young modulus) and by semiquantitative Likert scale–based assessment of experienced physicians.

Results:

For diagnosing insertional Achilles tendinopathy, semiquantitative MRI and power Doppler were most favorable (diagnostic accuracy, 95%), while the cross-sectional area of MRI revealed 89% accuracy in the ROC analyses (area under the curve [AUC], 0.911; P < .001). For diagnosing midportion Achilles tendinopathy, semiquantitative MRI and B-mode were most favorable (diagnostic accuracy, 87%), while UTC echo types 3 and 4 revealed 86% and 87% accuracy, respectively, in the ROC analyses (AUC, 0.911 and 0.941, respectively; P < .001). However, for quantitative and semiquantitative evaluation of diagnostic accuracy in both insertional and midportion Achilles tendinopathy, there was no significant difference in favor of one imaging modality over the others. Compared with baseline, only SWE showed a significant change at the 6-month follow-up (P = .003-.035), but there were only fair to poor monitoring accuracies of 71% (insertion) and 60% (midportion). However, compared with the other modalities, the monitoring accuracy of SWE was significantly higher (P = .002-.039).

Conclusion:

There was no statistically significant difference in favor of one imaging modality over the others, but MRI revealed the highest overall diagnostic accuracy for the diagnosis of both insertional and midportion Achilles tendinopathy.

Exercise-Based Muscle Development Programmes and Their Effectiveness in the Functional Recovery of Rotator Cuff Tendinopathy: A Systematic Review

(1) Background: Rotator cuff (RC) tendinopathy causes pain and functional limitation of the shoulder. Physical exercises are effective therapies but there is no consensus on which exercise programme is the most appropriate. Objective: To analyze and compare the effectiveness of different intervention modalities-based exclusively on physical exercise muscle-development programs to improve shoulder pain and function in RC tendinopathy. (2) Methods: Systematic review (PRISMA) through a search in PubMed, WOS, PEDro, Cinahl, Scopus and Dialnet. The PEDro Scale and the Cochrane Risk of Bias analyzed the methodological quality. A pre-established table collected data on: patients, interventions, outcome measures and results. A narrative synthesis of the results was conducted. (3) Results: eight articles were selected (Cochrane: low risk of bias; PEDro: good quality). All assessed programs were effective. Only one study found statistically and clinically significant differences in favour of eccentric training. The exercises used were: eccentric/concentric/conventional, open/closed kinetic chain, with/without co-activation of glenohumeral muscle, with/without pain, and in clinic/at home. (4) Conclusions: All exercise programs were effective in RC tendinopathy, improving pain and shoulder function. No solid results were obtained when the interventions were compared due to their heterogeneity. Patients perception assessment tools were the most widely used. Amount of load applied should be considered.

Acute-Onset Achilles Tendon Pain and Swelling Treated with an Amniotic Fluid-Derived Allograft: A Case Study

BACKGROUND

Tendinopathies are common musculoskeletal disorders that often develop because of chronic loading and failed healing. Tendinopathy related to systemic inflammation has been less extensively examined. Furthermore, although the use of biological agents to treat tendinopathies continues to gain popularity, the use of amniotic fluid-derived allografts in outpatient settings to resolve tendinopathies requires further evaluation.

METHODS

The focus of this case report is a 25-year-old man who presented for a second opinion, having been diagnosed with Haglund deformity and Achilles tendinopathy. At the time of presentation, he complained of 10 of 10 pain to the right Achilles tendon. He was treating the injury conservatively with intermittent use of a controlled ankle motion boot and working with physiotherapy for approximately 5 months before presentation. Diagnostic ultrasound along with magnetic resonance imaging indicated distal thickening of the Achilles tendon, substantial fluid and edema in the Kager fat pad, and retrocalcaneal erosions with bursitis. Conservative management did not resolve the symptoms. As an alternative to surgery, the patient elected to undergo an Achilles tendon injection of an amniotic fluid-derived allograft. Before and after the initial injection, a microdialysis catheter was inserted into the Achilles peritendinous space to sample local levels of extracellular matrix enzymes and growth factors important for tendon remodeling. The patient received considerable relief with the initial injection, but did not return to full strength. Over the subsequent 8 weeks, the patient was followed closely and was able to return to daily activities with minimal pain. He was not able to return to a more active lifestyle without further Achilles pain, so a second amniotic fluid-derived allograft injection was performed 8 weeks after the initial injection.

RESULTS

Injection of the initial allograft resulted in significant improvement, but not complete resolution of pain and swelling. Microdialysis findings suggested a reduction in peritendinous levels of the cytokine interlukin-6 in addition to changes in extracellular matrix regulatory enzymes. After 8 weeks of additional conservative therapy and a second injection, no further improvement in pain was noted.

CONCLUSIONS

Based on the clinical improvement of symptoms in this individual and the changes seen with microdialysis methodology, the authors find the use of amniotic fluid-derived allograft injection for treatment of Achilles pain in this patient to be a viable treatment. Additional comorbidities of systemic inflammatory polyarthritis and possible seronegative disease were addressed after rheumatology consultation with a variety of medications that provided the patient additional relief of his symptoms. The patient ultimately moved and was lost to further follow-up.

Immediate and long-term effects of mechanical loading on Achilles tendon volume: A systematic review and meta-analysis

The Achilles tendon (AT) may experience changes in dimensions related to fluid flow under load. The extent to which fluid flow involves redistribution within or flow out of the tendon is not known and could be determined by investigating volume changes. This study aimed to synthesize data on immediate and long-term effects of loading on tendon volume among people with a healthy AT and midportion Achilles tendinopathy (MAT). A secondary aim was to synthesise data from the included studies investigating parallel change in cross-sectional area and length. Systematic electronic search was performed in MEDLINE, EMBASE, CINAHL, AMED, and Scopus from inception until May 2020. Standardized mean differences (SMDs) were calculated for intervention-induced changes from baseline for all outcomes. Methodological quality was assessed using modified version of Newcastle Ottawa Scale (NOS). Twelve studies were included in meta-analysis. For healthy AT, there were negligible to small changes in volume following cross-country running (-0.33 [95% CI = -1.11 to 0.45] (P = 0.41)) and isometric exercise (0.01 [95% CI = -0.54 to 0.55] (P = 0.98)) and a large increase at the short-term with 12-week isometric protocol (0.88 [95% CI = -0.10 to1.86] (P = 0.08)). For MAT, there was an immediate large reduction in volume with isometric exercise (-1.24 [95% CI = -1.93 to -0.55] (P = 0.0004)), small increase with eccentric exercise (0.41 [95% CI = -0.18 to 1.01](P = 0.18)) and small reduction at the short-term with long-term interventions (-0.46 [95% CI = -0.87 to -0.05] (P = 0.03)). This meta-analysis suggests that healthy AT remain isovolumetric with acute interventions while MAT exhibit immediate and short-term volume reductions in response to different interventions.

Load progression criteria in exercise programmes in lower limb tendinopathy: a systematic review

OBJECTIVE

The objective of this study is to summarise and analyse the current literature about what progression criteria are applied in loading exercise programmes in lower limb tendinopathies and their evidence and effectiveness.

DESIGN

Systematic review.

METHODS

PubMed, Embase, Scopus and PEDro were searched from inception to 24 September 2020. The inclusion criteria were randomised controlled trials that included patients with midportion Achilles, patellar or gluteal tendinopathy; assessed function, pain or performance; included at least one group where progressive physical exercise was administered as monotherapy; included at least a control group. We excluded studies that included subjects with previous tendon surgical treatment; studies with control group that conducted a supplemented modality of the exercise performed in the intervention group. A narrative synthesis was conducted. Cohen's d and the percentage of change of main clinical and performance outcomes were obtained. Methodological quality was assessed using the PEDro scale.

RESULTS

Thirty studies that described progression criteria were included. Six types of criteria grouped in two categories were identified and included in a new classification proposal: pain as a primary criterion (evoking and avoid-pain based), and pain and symptom control as a secondary criterion (conditioning stages, fatigue-based, subjective perception and temporary linear increase). Most of the studies applied a pain-based criterion. Criteria based on conditioning stages were also commonly applied. Other criteria such as fatigue, a temporary linear increase, or the subjective perception of the patient's abilities were occasionally applied.

CONCLUSIONS

There is a predominant use of pain-based criteria, but the utilisation of these criteria is not supported by strong evidence. This review evidences the need for studies that compare the same exercise programme using different progression criteria. A new classification of the existing progression criteria is proposed based on the use of pain as the primary or secondary criterion.

PROSPERO REGISTRATION NUMBER

CRD42018110997.

Association Between Clinical and Imaging Outcomes After Therapeutic Loading Exercise in Patients Diagnosed With Achilles or Patellar Tendinopathy at Short- and Long-Term Follow-up: A Systematic Review

OBJECTIVE

To determine the association between clinical and imaging outcomes after therapeutic loading exercise in Achilles tendinopathy (AT) and patellar tendinopathy (PT) populations at both short- and long-term follow-up.

DATA SOURCES

The PUBMED and EMBASE databases were searched (up to June 2017) to identify articles that meet the inclusion criteria: (1) patients diagnosed with AT (insertional or midportion) or PT; (2) rehabilitation based on therapeutic loading exercise; and (3) assessment of clinical outcomes and tendon structure using an imaging modality.

MAIN RESULTS

Two independent reviewers screened 2894 search results, identifying 21 suitable studies. According to the studies included in this review, clinical results showed significant improvements for patients with AT and PT after eccentric exercise (ECC) and heavy slow resistance (HSR) at short- and long-term follow-up. Imaging outcomes were not consistent. Moderate-to-strong evidence for patients with AT suggested an association between clinical outcomes and imaging outcomes (tendon thickness and tendon neovascularization) after ECC at long-term follow-up. For patients with PT, there was moderate evidence supporting an association between clinical outcomes (questionnaire score and pain) and imaging (tendon thickness and tendon neovascularization) after ECC at short-term follow-up. For both the AT and PT groups, there was moderate evidence for an association between clinical outcomes and tendon thickness and neovascularization after HSR exercise. Results related to the HSR exercise should be interpreted with caution because of the small number of studies.

CONCLUSIONS

Based on the findings of the present review, the use of imaging outcomes as a complementary examination to the clinical assessment was confirmed. Overall, an improvement in clinical outcomes seems to be associated with a reduction in tendon thickness and tendon neovascularization. Clinicians should be aware that during the interpretation of the imaging outcomes, factors such as tendinopathy location, exercise modality performed, and a follow-up period should be considered.

Tendon Morphology and Mechanical Properties Are Associated With the Recovery of Symptoms and Function in Patients With Achilles Tendinopathy

Background:

Achilles tendinopathy is a debilitating overuse injury characterized by pain, altered Achilles tendon structure, and impaired functional performance. Evaluating tendon structure as part of the physical examination may help establish a well-defined prognosis. However, the usefulness of measuring tendon structure for developing a prognosis has been questioned since structural abnormalities can exist without symptoms.

Purpose:

To determine whether initial measures of tendon morphology and mechanical properties were associated with patient-reported symptoms and calf muscle endurance at baseline, 6-month follow-up, and 1-year follow-up by prospectively following a cohort of individuals with Achilles tendinopathy.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A total of 59 participants with midportion or insertional Achilles tendinopathy completed an initial assessment and follow-up assessments at 6 months and 1 year. At the initial assessment, patient-reported symptoms, calf muscle endurance, and Achilles tendon thickening were evaluated, and Achilles tendon mechanical properties were estimated. At the 6-month and 1-year follow-up assessments, patient-reported symptoms and calf muscle endurance were reevaluated.

Results:

Greater Achilles tendon thickening at the initial assessment was consistently associated with worse patient-reported symptoms and calf muscle endurance at each assessment. Changes in symptoms over the year were moderated by the initial shear modulus of the tendon, with a lower shear modulus associated with less improvement in symptoms. Lower viscosity at the initial assessment was also associated with worse calf muscle endurance at each assessment.

Conclusion:

Measures of tendon morphology and mechanical properties appear to be associated with patient-reported symptoms and calf muscle function for patients with Achilles tendinopathy.

Adaptation of Tendon Structure and Function in Tendinopathy With Exercise and Its Relationship to Clinical Outcome

CONTEXT

Exercise is seen as the most evidence-based treatment for managing tendinopathy and although the type of exercise used to manage tendinopathy may induce adaptation in healthy tendons, it is not clear whether these adaptations occur in tendinopathy and if so whether they are associated with improved clinical outcomes.

OBJECTIVE

The aim of the study was to synthesize available evidence for adaptation of the Achilles tendon to eccentric exercise and the relationship between adaptation (change in tendon thickness) and clinical outcomes among people with Achilles tendinopathy.

EVIDENCE ACQUISITION

The search was performed in September 2018 in several databases. Studies investigating the response (clinical outcome and imaging on ultrasound/magnetic resonance imaging) of pathological tendons (tendinopathy, tendinosis, and partial rupture) to at least 12 weeks of eccentric exercise were included. Multiple studies that investigated the same interventions and outcome were pooled and presented in effect size estimates, mean difference, and 95% confidence intervals if measurement scales were the same, or standard mean difference and 95% confidence intervals if measurements scales were different. Where data could not be pooled the studies were qualitatively synthesized based on van Tulder et al.

EVIDENCE SYNTHESIS

Eight studies met the inclusion and exclusion criteria and were included in the review. There was strong evidence that Achilles tendon thickness does not decrease in parallel with improved clinical outcomes.

CONCLUSIONS

Whether a longer time to follow-up is more important than the intervention (ie, just the time per se) for a change in tendon thickness remains unknown. Future studies should investigate whether exercise (or other treatments) can be tailored to optimize tendon adaptation and function, and whether this relates to clinical outcomes.

Injection with autologous conditioned serum has better clinical results than eccentric training for chronic Achilles tendinopathy

PURPOSE

Chronic Achilles tendinopathy is one of the most common causes of malfunction and pain, which can lead to a significant reduction of the quality of life. The hypothesis of this study argues that autologous conditioned serum (i.e. Orthokine) injections in chronic midportion Achilles tendinopathy have a better outcome than eccentric training.

METHODS

This study investigates, retrospectively, the effects of peritendinous autologous conditioned serum injections as compared to standard eccentric training in 50 patients with chronic Achilles tendinopathy between 2012 and 2015. Before injection or eccentric training and 6 weeks, 12 weeks and 6 months thereafter, the patients were assessed by means of the VISA-A-G score (Victorian Institute of Sport Assessment-Achilles questionnaire-German). An MRI was also performed before and 6 months after injection and eccentric training.

RESULTS

Both patient groups had statistically significant better VISA-A-G scores after injection or eccentric training compared to the baseline before injection (90 vs 40, respectively, P < 0.001) or eccentric training (81 vs 47, respectively, P < 0.001). Comparing the baseline corrected VISA-A-G scores, patients in the autologous-conditioned-serum-group had significantly higher changes in VISA-A-G scores than the eccentric-training-group after 12 weeks (40 vs 36, P = 0.018) and 6 months (50 vs 34, P = 0.034). Both patient groups had statistically significant (P < 0.001) reduction of tendon thickness (autologous conditioned serum: 0.32; eccentric training: 0.24) and length of bursa (autologous conditioned serum: 0.24; eccentric training: 0.21) as well as significant (P < 0.001) improvement of tendon quality in MRI (autologous conditioned serum: 14 vs 1; eccentric training: 14 vs 2). There were no statistical differences in MRI-findings between the two groups.

CONCLUSION

Both therapies led to improvement of MRI-findings, including reduction of tendon thickness and tendon quality. Autologous-conditioned-serum-injections show greater clinical long-term benefit as compared to eccentric training and, therefore, offers a good alternative to eccentric training.

LEVEL OF EVIDENCE

Therapeutic studies, Level III.

Comparison of the Effect of 5 Different Treatment Options for Managing Patellar Tendinopathy: A Secondary Analysis

OBJECTIVE

Currently, no treatments exist for patellar tendinopathy (PT) that guarantee quick and full recovery. Our objective was to assess which treatment option provides the best chance of clinical improvement and to assess the influence of patient and injury characteristics on the clinical effect of these treatments.

DESIGN

A secondary analysis was performed on the combined databases of 3 previously performed double-blind randomized controlled trials.

PATIENTS

In total, 138 patients with PT were included in the analysis.

INTERVENTIONS

Participants were divided into 5 groups, based on the treatment they received: Extracorporeal shockwave therapy (ESWT) (n = 31), ESWT plus eccentric training (n = 43), eccentric training (n = 17), topical glyceryl trinitrate patch plus eccentric training (n = 16), and placebo treatment (n = 31).

MAIN OUTCOME MEASURES

Clinical improvement (increase of ≥13 points on the Victorian Institute of Sport Assessment-Patella score) after 3 months of treatment.

RESULTS

Fifty-two patients (37.7%) improved clinically after 3 months of treatment. Odds ratios (ORs) for clinical improvement were significantly higher in the eccentric training group (OR 6.68, P = 0.009) and the ESWT plus eccentric training group (OR 5.42, P = 0.015) compared with the other groups. We found evidence that a high training volume, a longer duration of symptoms, and older age negatively influence a treatment's clinical outcome (trend toward significance).

CONCLUSIONS

Our study confirmed the importance of exercise, and eccentric training in particular, in the management of PT. The role of ESWT remains uncertain. Further research focusing on the identified prognostic factors is needed to be able to design patient-specific treatment protocols for the management of PT.

Immediate effect of photobiomodulation therapy on Achilles tendon morphology and mechanical properties: an exploratory study

Objectives

Evaluate the immediate (within 4 hours) effects of laser-induced photobiomodulation (PBM) therapy on Achilles tendon morphology and mechanical properties in healthy and pathologic tendons.

Materials and Methods

Twenty people with healthy Achilles tendons and twelve people with Achilles tendinopathy participated. One Achilles tendon received PBM treatment following an established protocol and the contralateral side received a placebo treatment. Achilles tendon morphology and mechanical properties were evaluated bilaterally with ultrasound imaging and continuous shear wave elastography immediately before treatment, immediately after treatment, then 2- and 4-hours after treatment.

Results

There were no immediate effects of PBM on tendon morphology or mechanical properties when comparing the PBM-treated side and placebo-treated side within each cohort. Additionally, the effects of PBM did not differ between healthy and pathologic Achilles tendons.

Conclusion

When treated with a laser-induced PBM treatment, healthy and pathologic Achilles tendons do not have immediate (within 4 hours) changes in tendon morphology or mechanical properties. These findings suggest that PBM therapy can be administered before other clinical treatments or high-load activities.

Fasciotomy and Surgical Tenotomy for Chronic Achilles Insertional Tendinopathy A Retrospective Study Using Ultrasound-Guided Percutaneous Microresection

BACKGROUND

Achilles insertional tendon pathology is a common condition affecting a broad range of patients. When conservative treatments are unsuccessful, the traditional open resection, debridement, and reattachment of the Achilles tendon is a variably reliable procedure with significant risk of morbidity. Fasciotomy and surgical tenotomy using ultrasound-guided percutaneous microresection is used on various tendons in the body, but the efficacy has not been examined specifically for the Achilles tendon.

METHODS

A retrospective review evaluated 26 procedures in 25 patients who underwent Achilles fasciotomy and surgical tenotomy. The Foot Function Index was used to quantify pain, disability, activity limitation, and overall scores.

RESULTS

Mean Foot Function Index scores were as follows: pain, 8.53%; disability, 7.91%; activity limitation, 2.50%; and overall, 6.97%. Twenty index procedures were successful, and two patients repeated the procedure successfully for an overall 84.6% success rate in patients with chronic insertional pathology with mean surveillance of 16 months. There were no infections or systemic complications.

CONCLUSIONS

Ultrasound-guided percutaneous microresection is a safe and minimally invasive percutaneous alternative that can be used before proceeding to a more invasive open procedure.

Rate of Improvement of Pain and Function in Mid-Portion Achilles Tendinopathy with Loading Protocols: A Systematic Review and Longitudinal Meta-Analysis

BACKGROUND

Mid-portion Achilles tendinopathy is prevalent within both the athletic and non-athletic populations and loading protocols for Achilles tendinopathy are effective over time, though the rate of symptom change throughout rehabilitation is unknown.

OBJECTIVE

The objective of this study was to determine the rate of change in pain and function over time in patients while completing a loading protocol for mid-portion Achilles tendinopathy.

METHODS

A systematic review and longitudinal meta-analysis was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The databases PubMed, CINAHL (Ovid) and CINAHL (EBSCO) were searched for articles published from inception until 31 July, 2017. Our search focused on clinical trials and cohort studies examining changes in pain and function when completing a loading protocol for mid-portion Achilles tendinopathy. The primary outcome measure assessing pain and function was the Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire.

RESULTS

A total of 31 separate cohorts (24 studies) were eligible, with follow-up ranging from 2 weeks to 6 months. The data were pooled to create the mean (standard deviation) of change from baseline at each time point. The data demonstrated an improvement in pain and function as early as 2 weeks that appeared to peak at 12 weeks with a mean (standard deviation) of 21.11 (6.61) points of change on the VISA-A.

CONCLUSION

The improvement in pain and function during rehabilitation suggests future research should be directed toward investigating contributing mechanisms as tendon structure on imaging does not change within 2 weeks and muscular hypertrophy is not seen for at least 4 weeks following the inception of a loading protocol. Systematic Review Registry: PROSPERO registration number: CRD42017062737 ( https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=62737 ).

Predicting Failure of Nonoperative Treatment for Insertional Achilles Tendinosis

Nonoperative treatment for midportion Achilles tendinosis is well defined by the literature. Multiple modalities are described for the management of insertional Achilles pathology, but no consensus exists regarding efficacy. Surgical intervention for insertional Achilles tendinosis (IAT) is successful greater than 80% of the time. Our objective was to risk stratify patients who would fail nonsurgical management of IAT and thus benefit progressing to surgery. We reviewed the records of 664 patients with IAT. The cohort was 53% male and 80% obese. Mean age was 53.7 years (standard deviation 14.7 years). Average duration of symptoms was 10.4 months (standard deviation 28 months). Of the parameters collected, 4 were found to correlate with failing nonoperative treatment: visual analog scale, limited ankle range of motion, previous corticosteroid injection, and presence of Achilles tendon enthesophyte. We found that as the number of risk factors increased so did the chance of failing nonoperative treatment. With all 4 parameters, chance of failing conservative treatment was only 55%. Thus, nonoperative management should be exhausted until surgery is the only remaining option. However, the presence of one of the aforementioned risk factors can aid a surgeon in the decision to pursue surgery in the appropriate clinical scenario.

LEVELS OF EVIDENCE

Level IV: Retrospective Case series.

The tendinopathic Achilles tendon does not remain iso-volumetric upon repeated loading: insights from 3D ultrasound

Mid-portion Achilles tendinopathy (MAT) alters the normal three-dimensional (3D) morphology of the Achilles tendon (AT) at rest and under a single tensile load. However, how MAT changes the 3D morphology of AT during repeated loading remains unclear. This study compared the AT longitudinal, transverse and volume strains during repeated loading in MAT with those of the contralateral tendon in people with unilateral MAT. Ten adults with unilateral MAT performed 10 successive 25 second submaximal (50%) voluntary isometric plantarflexion contractions with both legs. Freehand 3D ultrasound scans were recorded and used to measure whole AT, free AT, and proximal AT longitudinal strains and free AT cross-sectional area (CSA) and volume strains. The free AT experienced higher longitudinal and CSA strain and reached steady state following a greater number of contractions (5 contractions) in MAT compared to the contralateral tendon (3 contractions). Further, free tendon CSA and volume strained more in MAT than contralateral tendon from the first contraction, whereas free AT longitudinal strain was not greater than the contralateral tendon until the fourth contraction. Volume loss from the tendon core therefore preceded the greater longitudinal strain in MAT. Overall, these findings suggest that the tendinopathic free AT experiences an exaggerated longitudinal and transverse strain response under repeated loading that is underpinned by an altered interaction between solid and fluid tendon matrix components. These alterations are indicative of accentuated poroelasticity and an altered local stress-strain environment within the tendinopathic free tendon matrix, which could affect tendon remodelling via mechanobiological pathways.

Tendinopathy: Is Imaging Telling Us the Entire Story?

Synopsis Tendinopathy is frequently associated with structural disorganization within the tendon. As such, the clinical use of ultrasound and magnetic resonance imaging for tendinopathy has been the focus of numerous academic studies and clinical discussions. However, similar to other musculoskeletal conditions (osteoarthritis and intervertebral disc degeneration), there is no direct link between tendon structural disorganization and clinical symptoms, with findings on imaging potentially creating a confusing clinical picture. While imaging shows the presence and extent of structural changes within the tendon, the clinical interpretation of the images requires context in regard to the features of pain and the aggravating loads. This review will critically evaluate studies that have investigated the accuracy and sensitivity of imaging in the detection of clinical tendinopathy and the methodological issues associated with these studies (subject selection, lack of a robust gold standard, reliance on subjective measures). The advent of new imaging modalities allowing for the quantification of tendon structure or mechanical properties has allowed new critical insight into tendon pathology. A strength of these novel modalities is the ability to quantify properties of the tendon. Research utilizing ultrasound tissue characterization and sonoelastography will be discussed. This narrative review will also attempt to synthesize current research on whether imaging can predict the onset of pain or clinical outcome, the role of monitoring tendon structure during rehabilitation (ie, does tendon structure need to improve to get a positive clinical outcome?), and future directions for research, and to propose the clinical role of imaging in tendinopathy. J Orthop Sports Phys Ther 2015;45(11):842-852. Epub 21 Sep 2015. doi:10.2519/jospt.2015.5880.

Eccentric or Concentric Exercises for the Treatment of Tendinopathies?

Synopsis Tendinopathy is a very common disorder in both recreational and elite athletes. Many individuals have recurrent symptoms that lead to chronic conditions and termination of sports activity. Exercise has become a popular and somewhat efficacious treatment regime, and isolated eccentric exercise has been particularly promoted. In this clinical commentary, we review the relevant evidence for different exercise regimes in tendinopathy rehabilitation, with particular focus on the applied loads that are experienced by the tendon and how the exercise regime may affect these applied loads. There is no convincing clinical evidence to demonstrate that isolated eccentric loading exercise improves clinical outcomes more than other loading therapies. However, the great variation and sometimes insufficient reporting of the details of treatment protocols may hamper the interpretation of what may be the optimal exercise regime with respect to parameters such as load magnitude, speed of movement, and recovery period between exercise sessions. Future studies should control for these loading parameters, evaluate various exercise dosages, and think beyond isolated eccentric exercises to arrive at firm recommendations regarding rehabilitation of individuals with tendinopathies. J Orthop Sports Phys Ther 2015;45(11):853-863. Epub 14 Oct 2015. doi:10.2519/jospt.2015.5910.

Gastrocnemius tendinosis--A frequent finding on MRI knee examination

OBJECTIVE

Gastrocnemius tendinosis (GT) is one potential cause for posterior knee pain, commonly overlooked on clinical examinations and imaging. This study assesses the frequency of GT on MR imaging in a convenience sample based on a database search and associations with other articular pathologies and clinical findings.

SUBJECTS AND METHODS

With IRB approval, retrospective review was completed on 300 randomly selected MR knee exams performed from February 2009 to June 2010. Following de-identification, axial T2 and sagittal PD images, with or without fat suppression, were reviewed by 2 radiologists. The gastrocnemius tendon femoral attachments were graded as normal, mild (few cysts, thickening, intermediate signal) or severe GT (multiple cysts, marrow edema, tear). Select associated MR findings of internal derangement were documented. Clinical charts were reviewed for clinical presentation, physical exam findings, and select demographics.

RESULTS

The inter-observer reliability for presence/grading of GT was very high (kappa statistic=0.97). Frequency of GT was 50.33%, most frequently involving medial head of gastrocnemius (63.6%). Grades of GT were 41.7% and 17.2% for mild and severe respectively. Univariate analysis showed statistically significant relationship between grade of GT with arthrosis (p=0.05) and clinical joint effusion (p=0.02). Multivariate analysis showed higher odds of severe GT for individuals with medial plus lateral GT. Statistical significance was noted for presence of both GT and ACL tear (13.9%; p=0.02).

CONCLUSION

Significant findings of our analysis included GT presented with predominant involvement of medial head of gastrocnemius tendon, mild in severity, strong association with ACL tear, presented frequently as posterior knee pain, limited joint motion and clinical joint effusion. However, there was no statistically significant association between demographic features and medical comorbidities in the patients. Increased understanding of frequency of GT allows more accurate reporting of MR knee exam and systematic search for associated abnormalities.

Anatomy of the triceps surae: a pictorial essay

Gastrocnemius contracture has recently gained relevance owing to its suggested relationship with foot disorders such as metatarsalgia, plantar fasciopathy, hallux valgus, and others. Consequently this has induced a renewed interest in surgical lengthening techniques, including proximal gastrocnemius release, to resolve gastrocnemius contracture in patients with foot disorders. This article describes and discusses the general anatomy of the triceps surae and the surgical anatomy of the gastrocnemius.

Effects of 12-wk eccentric calf muscle training on muscle-tendon glucose uptake and SEMG in patients with chronic Achilles tendon pain

High-load eccentric exercises have been a key component in the conservative management of chronic Achilles tendinopathy. This study investigated the effects of a 12-wk progressive, home-based eccentric rehabilitation program on ankle plantar flexors' glucose uptake (GU) and myoelectric activity and Achilles tendon GU. A longitudinal study design with control ( n = 10) and patient ( n = 10) groups was used. Surface electromyography (SEMG) from four ankle plantar flexors and GU from the same muscles and the Achilles tendon were measured during submaximal intermittent isometric plantar flexion task. The results indicated that the symptomatic leg was weaker ( P < 0.05) than the asymptomatic leg at baseline, but improved ( P < 0.001) with eccentric rehabilitation. Additionally, the rehabilitation resulted in greater GU in both soleus ( P < 0.01) and lateral gastrocnemius ( P < 0.001) in the symptomatic leg, while the asymptomatic leg displayed higher uptake for medial gastrocnemius and flexor hallucis longus ( P < 0.05). While both patient legs had higher tendon GU than the controls ( P < 0.05), there was no rehabilitation effect on the tendon GU. Concerning SEMG, at baseline, soleus showed more relative activity in the symptomatic leg compared with both the asymptomatic and control legs ( P < 0.05), probably reflecting an effort to compensate for the decreased force potential. The rehabilitation resulted in greater SEMG activity in the lateral gastrocnemius ( P < 0.01) of the symptomatic leg with no other within- or between-group differences. Eccentric rehabilitation was effective in decreasing subjective severity of Achilles tendinopathy. It also resulted in redistribution of relative electrical activity, but not metabolic activity, within the triceps surae muscle.

The injured runner

Running is often recommended by physicians to maintain a healthy lifestyle. As more individuals participate in running-related activities, clinicians must be increasingly aware of common injuries. Training errors leading to overuse are the most common underlying factors in most running-related injuries. Clinicians need to keep in mind that the presenting injury is frequently the result of an inability to compensate for a primary dysfunction at another site. Although imaging may be helpful in differentiating among diagnoses with similar clinical presentations, a detailed history and physical examination are essential in making a correct diagnosis.

The role of eccentric exercise in sport injuries rehabilitation

INTRODUCTION

Sports injuries frequently involve tendons, muscles and ligaments. The variable outcome of surgery and medical treatment support early functional treatments. Eccentric exercise (EE) showed effectiveness in the management of Achilles tendinopathy (AT), patellar tendinopathy (PT) and lateral epicondyle tendinopathy (LET). Preliminary results of EE in other tendinopathies and sports injuries suggest its wide prescription in the sport rehabilitation field.

SOURCES OF DATA

A comprehensive search of PubMed, Web of Science, the Cochrane Collaboration Database, Physiotherapy Evidence Database (PEDro), Evidence Based Medicine (EBM) Search review, National Guidelines, Scopus and Google Scholar was performed using keywords such as 'eccentric exercise', 'sports injuries rehabilitation', 'tendinopathy', 'hamstrings strain' 'adductor injuries' and 'ACL reconstruction rehabilitation'.

AREAS OF AGREEMENT

EE, alone or associated with other therapies, represents a feasible, cost-effective and successful tool in the treatment of well-known targets and might be promising in shoulder tendinopathy, adductor-related groin pain, hamstring strains, and ACL rehabilitation.

AREA OF CONTROVERSY

The lack of standardization of protocols, the variable amount, quality and follow-up of studies, the different anatomy and pathophysiology of the therapeutic targets limit the evidence of applicability of EE to sports injuries.

GROWING POINTS

The role of pathology and biomechanics in the response to EE should be further investigated.

AREAS TIMELY FOR DEVELOPING RESEARCH

New randomized controlled trials should test the effectiveness of standardized EE regimens to various sites of sports injuries.

In vivo measurement of human achilles tendon morphology using freehand 3-D ultrasound

This study investigated the accuracy of phantom volume and length measurements and the reliability of in vivo Achilles tendon (AT) volume, length and cross-sectional area measurements obtained using freehand 3-D ultrasound. Participants (n = 13) were scanned on consecutive days under active and passive loading conditions. In vivo AT length was evaluated using a two-point method and an approach that accounted for AT curvature (centroid method). Three-dimensional ultrasound provided accurate measures of phantom volume and length (mean difference = 0.05 mL and 0.2 mm, respectively) and reliable in vivo measures of AT volume, length and average cross-sectional area, with all intra-class correlations coefficients greater than 0.98. The mean minimally detectable changes for in vivo AT volume, two-point length and centroid length were 0.2 mL, 1.5 mm and 2.0 mm, respectively. Two-point AT length underestimated centroid AT length by 0.7 mm, suggesting that the effect of curvature on in vivo AT length is negligible.

Dynamic contrast enhanced magnetic resonance imaging in chronic Achilles tendinosis

Background

Chronic Achilles tendinosis is a common problem. When evaluating and comparing different therapies there is a need for reliable imaging methods. Our aim was to evaluate if chronic Achilles tendinosis affects the dynamic contrast-enhancement in the tendon and its surroundings and if short-term eccentric calf-muscle training normalizes the dynamic contrast-enhancement.

Methods

20 patients with chronic Achilles tendinopathy were included. Median duration of symptoms was 31 months (range 6 to 120 months). Both Achilles tendons were examined with dynamic contrast enhanced MRI before and after a 12- week exercise programme of eccentric calf-muscle training. The dynamic MRI was evaluated in tendon, vessel and in fat ventrally of tendon. Area under the curve (AUC), time to peak of signal, signal increase per second (SI/s) and increase in signal between start and peak as a percentage (SI%) was calculated. Pain and performance were evaluated using a questionnaire.

Results

In the fat ventrally of the tendon, dynamic contrast enhancement was significantly higher in the symptomatic leg compared to the contralateral non-symptomatic leg before but not after treatment. Despite decreased pain and improved performance there was no significant change of dynamic contrast enhancement in symptomatic tendons after treatment.

Conclusion

In Achilles tendinosis there is an increased contrast enhancement in the fat ventrally of the tendon. The lack of correlation with symptoms and the lack of significant changes in tendon contrast enhancement parameters do however indicate that dynamic enhanced MRI is currently not a useful method to evaluate chronic Achilles tendinosis.

Achilles and patellar tendinopathy loading programmes : a systematic review comparing clinical outcomes and identifying potential mechanisms for effectiveness

INTRODUCTION

Achilles and patellar tendinopathy are overuse injuries that are common among athletes. Isolated eccentric muscle training has become the dominant conservative management strategy for Achilles and patellar tendinopathy but, in some cases, up to 45 % of patients may not respond. Eccentric-concentric progressing to eccentric (Silbernagel combined) and eccentric-concentric isotonic (heavy-slow resistance; HSR) loading have also been investigated. In order for clinicians to make informed decisions, they need to be aware of the loading options and comparative evidence. The mechanisms of loading also need to be elucidated in order to focus treatment to patient deficits and refine loading programmes in future studies.

OBJECTIVES

The objectives of this review are to evaluate the evidence in studies that compare two or more loading programmes in Achilles and patellar tendinopathy, and to review the non-clinical outcomes (potential mechanisms), such as improved imaging outcomes, associated with clinical outcomes.

METHODS

Comprehensive searching (MEDLINE, EMBASE, CINAHL, Current Contents and SPORTDiscus(™)) identified 403 studies. Two authors independently reviewed studies for inclusion and quality. The final yield included 32 studies; ten compared loading programmes and 28 investigated at least one potential mechanism (six studies compared loading programmes and investigated potential mechanisms).

RESULTS

This review has identified limited (Achilles) and conflicting (patellar) evidence that clinical outcomes are superior with eccentric loading compared with other loading programmes, questioning the currently entrenched clinical approach to these injuries. There is equivalent evidence for Silbernagel combined (Achilles) and greater evidence for HSR loading (patellar). The only potential mechanism that was consistently associated with improved clinical outcomes in both Achilles and patellar tendon rehabilitation was improved neuromuscular performance (e.g. torque, work, endurance), and Silbernagel-combined (Achilles) HSR loading (patellar) had an equivalent or higher level of evidence than isolated eccentric loading. In the Achilles tendon, a majority of studies did not find an association between improved imaging (e.g. reduced anteroposterior diameter, proportion of tendons with Doppler signal) and clinical outcomes, including all high-quality studies. In contrast, HSR loading in the patellar tendon was associated with reduced Doppler area and anteroposterior diameter, as well as greater evidence of collagen turnover, and this was not seen following eccentric loading. HSR seems more likely to lead to tendon adaptation and warrants further investigation. Improved jump performance was associated with Achilles but not patellar tendon clinical outcomes. The mechanisms associated with clinical benefit may vary between loading interventions and tendons.

CONCLUSION

There is little clinical or mechanistic evidence for isolating the eccentric component, although it should be made clear that there is a paucity of good quality evidence and several potential mechanisms have not been investigated, such as neural adaptation and central nervous system changes (e.g. cortical reorganization). Clinicians should consider eccentric-concentric loading alongside or instead of eccentric loading in Achilles and patellar tendinopathy. Good-quality studies comparing loading programmes and evaluating clinical and mechanistic outcomes are needed in both Achilles and patellar tendinopathy rehabilitation.

Overuse injuries

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

Programmable mechanical stimulation influences tendon homeostasis in a bioreactor system

Identification of functional programmable mechanical stimulation (PMS) on tendon not only provides the insight of the tendon homeostasis under physical/pathological condition, but also guides a better engineering strategy for tendon regeneration. The aims of the study are to design a bioreactor system with PMS to mimic the in vivo loading conditions, and to define the impact of different cyclic tensile strain on tendon. Rabbit Achilles tendons were loaded in the bioreactor with/without cyclic tensile loading (0.25 Hz for 8 h/day, 0-9% for 6 days). Tendons without loading lost its structure integrity as evidenced by disorientated collagen fiber, increased type III collagen expression, and increased cell apoptosis. Tendons with 3% of cyclic tensile loading had moderate matrix deterioration and elevated expression levels of MMP-1, 3, and 12, whilst exceeded loading regime of 9% caused massive rupture of collagen bundle. However, 6% of cyclic tensile strain was able to maintain the structural integrity and cellular function. Our data indicated that an optimal PMS is required to maintain the tendon homeostasis and there is only a narrow range of tensile strain that can induce the anabolic action. The clinical impact of this study is that optimized eccentric training program is needed to achieve maximum beneficial effects on chronic tendinopathy management.

Physiological Achilles tendon length and its relation to tibia length

OBJECTIVE

The optimal intraoperative Achilles tendon length (ATL) adjustment is crucial for the physiological functioning of the musculotendinous unit. To date, the resting ATL and its relation to tibia length (TL) have never been defined in healthy subjects. We thus performed metric measurements of the ATL and TL.

DESIGN

Case series.

SETTING

Clinical and radiological measurements.

PARTICIPANTS

Fifty-two subjects placed in a 3-T magnetic resonance imaging with the ankle in neutral position.

MAIN OUTCOME MEASURES

Unilateral ATL measured from the calcaneal insertion to the beginning of the medial gastrocnemius muscle, TL measured from the intercondylar eminence to the center of the ankle, and qualitative tendon parameters in T2 sequences and human parameters were noted; results were correlated with age, gender, body height, weight, body mass index (BMI), and side of the AT and TL.

RESULTS

The mean ATL was 180.6 ± 25.0 mm and the mean TL was 371.9 ± 25.4 mm with an ATL:TL ratio of 49 ± 5%. Achilles tendon length correlated significantly with body height (R = 38%, P < 0.0001) and with TL (R = 41%, P < 0.0001) but did not correlate with age, BMI, and side of the AT. Tibia length correlated with body height (R = 83%, P < 0.0001) and in multivariate linear regression, TL was the only independent predictor of ATL following the algorithm, ATL (mm) = 0.6 × TL (mm) - 53 (R = 41%).

CONCLUSIONS

We defined a new way to measure the ATL in a consistent way in healthy subjects and showed correlations between ATL, TL and body height and defined an algorithm of ATL based on TL. The ATL and the ATL-algorithm might be important in patients with impaired tendons such as AT ruptures.

Do structural changes (eg, collagen/matrix) explain the response to therapeutic exercises in tendinopathy: a systematic review

BACKGROUND

Previous reviews have highlighted the benefit of loaded therapeutic exercise in the treatment of tendinopathy. Changes in observable structural outcomes have been suggested as a possible explanation for this response to therapeutic exercise. However, the mechanism for the efficacy of therapeutic exercise remains unclear.

OBJECTIVE

To systematically review the relationship between the observable structural change and clinical outcomes following therapeutic exercise.

DATA SOURCES

An electronic search of AMED, CiNAHL, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PEDro and SPORTDiscus was undertaken from their inception to June 2012.

STUDY ELIGIBILITY CRITERIA

Any study design that incorporated observable structural outcomes and clinical outcomes when assessing the effect of therapeutic exercise on participants with tendinopathy.

STUDY APPRAISAL AND SYNTHESIS METHODS

Included studies were appraised for risk of bias using the tool developed by the Cochrane Back Review Group. Due to heterogeneity of studies, a qualitative synthesis was undertaken.

RESULTS

Twenty articles describing 625 patients were included. Overall, there is a strong evidence to refute any observable structural change as an explanation for the response to therapeutic exercise when treated by eccentric exercise training. Moderate evidence does exist to support the response of heavy-slow resistance training (HSR).

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

The available literature does not support observable structural change as an explanation for the response of therapeutic exercise except for some support from HSR. Future research should focus on indentifying other explanations including neural, biochemical and myogenic changes.

REGISTRATION NUMBER

Registered with PROSPERO, registration number CRD42011001638.

Tendinosis: pathophysiology and nonoperative treatment

Tendinosis is a troublesome clinical entity affecting many active people. Its treatment remains a challenge to sports medicine clinicians. The etiopathophysiology of tendinosis has not been well delineated. The known pathophysiology and the recent advances in the understanding of the etiologic process of tendinosis are discussed here, including new concepts in mechanotransduction and the biochemical alterations that occur during tendon overload. The optimal, nonoperative treatment of tendinosis is not clear. This article reviews recent evidence of the clinical efficacy of the following interventions: eccentric exercise, extracorporal shock wave treatment, corticosteroid and nonsteroidal anti-inflammatory medications, sclerosing injections, nitric oxide, platelet-rich plasma injections, and matrix metalloproteinase inhibitors. Eccentric exercise has strongest evidence of efficacy. Extracorporal shock wave treatment has mixed evidence and needs further study of energy and application protocols. Sclerosing agents show promising early results but require long-term studies. Corticosteroid and nonsteroidal anti-inflammatory medications have not been shown to be effective, and many basic science studies raise possible concerns with their use. Nitric oxide has been shown in several basic science studies to be promising, but clinical efficacy has not been well established. More clinical trials are needed to assess dosing, indications, and clinical efficacy of nitric oxide. Platelet-rich plasma injections have offered encouraging short-term results. Larger and longer-term clinical trials are needed to assess this promising modality. Matrix metalloproteinase inhibitors have had few clinical studies, and their role in the treatment of tendinosis is still in the early phase of investigation.

Rehabilitation of the Overhead Athlete's Elbow

The activities required during overhead sports, particularly during baseball pitching, produce large forces at the elbow joint. Injuries to the elbow joint frequently occur in the overhead athlete because of the large amount of forces observed during the act of throwing, playing tennis, or playing golf. Injuries may result because of repetitive overuse, leading to tissue failure. Rehabilitation following injury or surgery to the throwing elbow is vital to fully restore normal function and return the athlete to competition as quickly and safely as possible. Rehabilitation of the elbow, whether following injury or postsurgical, must follow a progressive and sequential order, building on the previous phase, to ensure that healing tissues are not compromised. Emphasis is placed on restoring full motion, muscular strength, and neuromuscular control while gradually applying loads to healing tissue. In addition, when one is creating a rehabilitation plan for athletes, it is imperative to treat the entire upper extremity, core, and legs to create and dissipate the forces generated at each joint.

Tendinopathy treatment: where is the evidence?

Tendinopathy is a common and debilitating condition that results in significant deficits in performance and prolonged time away from activity. For this reason, much effort has been placed in defining beneficial and cost-effective treatments. This review has outlined the current literature on some of the most widely used therapies for cases of tendinopathy. As such, recommendations remain limited by the evidence available. The variability in both quantity and quality of research into tendinopathy treatments makes it difficult to make definitive treatment recommendations. In general, however, a reasonable first line of treatment for tendinopathy should include a course of NSAIDs and eccentric exercise-based physical therapy. Corticosteroid injections seem to offer excellent short-term pain relief but lack long term efficacy. Alternative injections, such as PRP, have shown short-term efficacy for tendinopathy sufferers; data are lacking to support sclerosing agents and proteinase inhibitors. Operative management seems to offer some benefit in symptomatic relief but carries a higher complication rate than other treatment options and should be reserved only for patients recalcitrant to other more conservative options. Although the inability to make definitive therapeutic recommendations in some instances is discouraging, it is important to note that a lack of high-quality evidence supporting specific treatments does not necessarily imply that they are inherently ineffective. Given the growing prevalence of tendinopathy and the impact it has on the general public, it is more important now than ever to continue the search for the most effective and accessible treatment modalities.