Color Doppler ultrasound findings in patellar tendinopathy (jumper's knee)

Sonographic Assessment of Asymptomatic Patellar and Achilles Tendons to Predict Future Pain: A Systematic Review and Meta-analysis

OBJECTIVE

Patients with clinical tendinopathy often demonstrate significant abnormalities with ultrasound (US) imaging. Tendon abnormalities likely precede pain in these patients. The purpose of this review was to systematically evaluate the available literature regarding the utility of US imaging as a method to predict Achilles and patellar tendon pain.

DESIGN

Systematic review and meta-analysis. Inclusion criteria were as follows: prospective studies of Achilles and patellar tendon pain development with baseline US measurements, follow-up clinical measurements, and English-language studies published after 2000. Exclusion criteria were prior rupture or surgery and presence of rheumatologic disorder.

SETTING

N/A.

PATIENTS

Athletes without Achilles or patellar tendon pain at baseline.

INTERVENTIONS

N/A.

MAIN OUTCOME MEASURES

Risk ratios (RRs) were identified for the development of pain in those with Achilles or patellar tendon sonographic abnormalities.

RESULTS

This review of 16 studies included 810 Achilles and 1156 patellar tendons from a variety of sports and demonstrated that the RR for pain development from abnormal Patellar and Achilles tendons was 6.07 [95% confidence interval (CI), 2.88-12.81; P < 0.001] and 3.96 [95% CI, 2.21-7.09; P < 0.001], respectively. The positive and negative predictive values of an abnormal US finding were 27.2% and 92.0% for the Achilles tendon and 27.2% and 93.5% for the patellar tendon, respectively.

CONCLUSIONS

This systematic review and meta-analysis identified that the use of asymptomatic US scanning of the Achilles or patellar tendon has a low positive predictive value but a high negative predictive value for the future development of pain.

Challenging the assumption of uniformity in patellar tendon structure: Regional patellar tendon morphology and mechanical properties in vivo

Patellar tendons are assumed to be uniform in morphology and mechanical properties despite a higher prevalence of tendinopathies observed in the medial region. The purpose of this study was to compare the thickness, length, viscosity, and shear modulus of the medial, central, and lateral regions of healthy patellar tendons of young males and females in vivo. B-mode ultrasound and continuous shear wave elastography were performed on 35 patellar tendons (17 females, 18 males) over three regions of interest. A linear mixed-effects model (α = 0.05) was used to determine differences between the three regions and sexes followed by pairwise comparisons for significant findings. The lateral region (mean [95% confidence interval] = 0.34 [0.31-0.37] cm) was thinner compared with the medial (0.41 [0.39-0.44] cm, p < 0.001), and central (0.41 [0.39-0.44] cm, p < 0.001) regions regardless of sex. Viscosity was lower in the lateral (19.8 [16.9-22.7] Pa-s) versus medial region (27.4 [24.7-30.2] Pa-s, p = 0.001). Length had a region-by-sex interaction (p = 0.003) characterized by a longer lateral (4.83 [4.54-5.13] cm) versus medial (4.42 [4.12-4.72] cm) region in males (p < 0.001), but not females (p = 0.992). Shear modulus was uniform between regions and sexes. The thinner, and less viscous lateral patellar tendon may reflect the lower load the tendon experiences explaining the differences in regional prevalence of developing tendon pathology. Statement of Clinical Significance: Healthy patellar tendons are not uniform in morphology or mechanical properties. Considering regional tendon properties may help guide targeted interventions for patellar tendon pathologies.

Efficacy of ultrasound guided dry needling as an adjunct to conventional physical therapy for patients with jumper’s knee: A randomized controlled trial

Background

Jumper’s knee is a degenerative condition among athletes, and it has been treated with conventional physical therapy (CPT). Ultrasound guided dry needling (USG-DN) is a relatively new technique to explore clinical outcomes in patients with tendinopathy.

Methods

This parallel group, single-blinded randomized controlled trial was carried out involving 94 athletes with clinically diagnosed jumper’s knee, divided into an intervention group (USG-DN + CPT, n = 47) and a control group (CPT, n = 47). Participants received a 4-week programme; the intervention group received ultrasound guided patellar tendon dry needling (DN) in conjunction with CPT. The control group received only CPT. The visual analog scale (VAS), Victorian institute of sports assessment-Patellar tendinopathy (VISA-P) questionnaire, Lysholm scale, Knee injury and osteoarthritis outcome score (KOOS) and ultrasonographic features of patellar tendinopathy were evaluated at baseline,1 week, 2 weeks, and 4 weeks. The data were analyzed through SPSS-26.

Results

The study found statistically significant differences (P < 0.05) regarding VAS, Lysholm, VISA-P, and KOOS scales at baseline, 1st, 2nd, and 4th week post-intervention. Within-group differences also showed statistically significant results after the intervention. There were significant results observed in ultrasonographic outcomes between both groups at 1 month post-intervention (all P < 0.05).

Conclusion

The results of the current study suggest, ultrasound guided DN of patellar tendon in combination with CPT reduced pain, improved function, and showed a tendency to decrease tendon thickness in patients with patellar tendinopathy.

Clinical Trial Registration Number

(IRCT20210409050913N1). Dated: 17.04.2021. https://www.irct.ir/user/trial/55607/view.

A Case of Chronic Deep Infrapatellar Bursitis Complicated by Patellar Tendinopathy and its Evaluation With Musculoskeletal Ultrasound

Knee pain is a very common complaint in routine physiatry and orthopedic practice. While bursitis is a well-known and common cause of knee pain, deep infrapatellar bursa (DIPB) involvement is relatively less common. Inflammation of DIPB occurs commonly due to either direct trauma or overuse, but other rare causes have also been reported in the literature including infection, juvenile idiopathic arthritis, gout, and juvenile ankylosing spondylitis. We report a case of chronic inflammation of DIPB caused by direct trauma and associated with patellar tendinopathy. Additionally, we describe the characteristic findings on musculoskeletal ultrasonography (MSK-USG). For ultrasound evaluation, the patient should lie supine with the knee slightly flexed. Deep infrapatellar bursitis can be seen as an anechoic fluid-filled structure immediately posterior to the distal patellar tendon and anterior to the tibial tuberosity. While MRI can confirm the diagnosis of bursitis, MSK-USG can be quick, highly sensitive, and is able to confirm the diagnosis as well as to detect dynamic changes in the patellar tendon and adjacent structures. USG can also help in the treatment by guiding corticosteroid injection into the bursa. Activity modification and eccentric exercises play an important role in the rehabilitation program in these cases.

Tendinopathy and tendon material response to load: What we can learn from small animal studies

Tendinopathy is a debilitating disease that causes as much as 30% of all musculoskeletal consultations. Existing treatments for tendinopathy have variable efficacy, possibly due to incomplete characterization of the underlying pathophysiology. Mechanical load can have both beneficial and detrimental effects on tendon, as the overall tendon response depends on the degree, frequency, timing, and magnitude of the load. The clinical continuum model of tendinopathy offers insight into the late stages of tendinopathy, but it does not capture the subclinical tendinopathic changes that begin before pain or loss of function. Small animal models that use high tendon loading to mimic human tendinopathy may be able to fill this knowledge gap. The goal of this review is to summarize the insights from in-vivo animal studies of mechanically-induced tendinopathy and higher loading regimens into the mechanical, microstructural, and biological features that help characterize the continuum between normal tendon and tendinopathy. STATEMENT OF SIGNIFICANCE: This review summarizes the insights gained from in-vivo animal studies of mechanically-induced tendinopathy by evaluating the effect high loading regimens have on the mechanical, structural, and biological features of tendinopathy. A better understanding of the interplay between these realms could lead to improved patient management, especially in the presence of painful tendon.

[Tendinopathies of the Achilles tendon]

Disorders of the Achilles tendon are among the most frequent musculoskeletal injuries in athletes as well as in the general population. It is very important to differentiate the different clinical pictures summarized under the general term achillodynia and to understand the pathogenesis in order to undertake the correct therapeutic measures. In the case of insertional tendinopathies in particular, a rheumatological origin should be clarified. Doppler ultrasound is the most important diagnostic tool. Evidence-based treatment methods include various training programs, shock wave treatment, diverse injection and surgical procedures, each of which are discussed in detail in this article.

A Systematic Review of the Inclusion of Non-Inflammatory Ultrasonographic Enthesopathy Findings in Enthesitis Scoring Indices

Ultrasound has advanced the diagnosis and management of patients with inflammatory rheumatic conditions. It can be used to identify and monitor enthesitis, a cardinal feature of spondyloarthropthies. Several enthesitis scoring systems utilizing ultrasound to determine entheseal involvement have been developed. These scoring systems generally rely on determining the presence or absence of erosions, tendon enlargement, power Doppler signal, or enthesophytes. This systematic review identified ultrasound scoring systems that have been utilized for evaluating enthesitis and what key components derive the score. Review of these scoring systems, however, demonstrated confounding as some of the score components including enthesophytes may be seen in non-inflammatory conditions and some components including erosions can be seen from chronic damage, but not necessarily indicate active inflammatory disease. What is furthermore limiting is that currently there is not an agreed upon term to describe non-inflammatory enthesopathies, further complicating these scoring systems. This review highlights the need for a more comprehensive ultrasound enthesopathy scoring index.

A Narrative Review of the Classification and Use of Diagnostic Ultrasound for Conditions of the Achilles Tendon

Enthesitis is a cardinal feature of spondyloarthropathies. The Achilles insertion on the calcaneus is a commonly evaluated enthesis located at the hindfoot, generally resulting in hindfoot pain and possible tendon enlargement. For decades, diagnosis of enthesitis was based upon patient history of hindfoot or posterior ankle pain and clinical examination revealing tenderness and/or enlargement at the site of the tendon insertion. However, not all hindfoot or posterior ankle symptoms are related to enthesitis. Advanced imaging, including magnetic resonance imaging (MRI) and ultrasound (US), has allowed for more precise evaluation of hindfoot and posterior ankle conditions. Use of US in diagnosis has helped confirm some of these cases but also identified other conditions that may have otherwise been misclassified without use of advanced imaging diagnostics. Conditions that may result in hindfoot and posterior ankle symptoms related to the Achilles tendon include enthesitis (which can include retrocalcaneal bursitis and insertional tendonopathy), midportion tendonopathy, paratenonopathy, superficial calcaneal bursitis, calcaneal ossification (Haglund deformity), and calcific tendonopathy. With regard to classification of these conditions, much of the existing literature uses confusing nomenclature to describe conditions in this region of the body. Some terminology may imply inflammation when in fact there may be none. A more uniform approach to classifying these conditions based off anatomic location, symptoms, clinical findings, and histopathology is needed. There has been much debate regarding appropriate use of tendonitis when there is no true inflammation, calling instead for use of the terms tendinosis or tendonopathy. To date, there has not been clear examination of a similar overuse of the term enthesitis in conditions where there is no underlying inflammation, thus raising the need for more comprehensive taxonomy.

Sclerotherapy and prolotherapy for chronic patellar tendinopathies - a promising therapy with limited available evidence, a systematic review

Chronic Patellar tendinopathy (CPT) is a frequent overuse disorder in athletes and active people. Sclerotherapy (ST) and prolotherapy (PT) are, among a wide range of conservative treatment options, two promising therapies and have shown positive results in other tendinopathies. Since the treatments' efficacy and safety are still not defined, this review sought to answer questions on recommendations for use in clinical utility, safety, and how to perform the injection in the most effective way. An electronic database search was conducted following the PRISMA guidelines. Inclusion criteria were set up according to the PICOS-scheme. Included were athletes and non-athletes of all ages with diagnosed painful CPT. Studies including patients suffering from patellar tendinopathy which can be originated to any systemic condition affecting the musculoskeletal system (e.g. disorders associated with rheumatism) and animal studies were excluded. Methodological quality (modified Coleman Methodology Score) and risk of bias (Cochrane Risk of Bias Assessment Tool 2.0) were assessed by two independent reviewers, with disagreements resolved with a third reviewer. The search yielded a total of 416 entries. After screening titles, abstracts, and full texts, ten articles were found for qualitative analysis. The mean Coleman Score was 64.57. Three randomized-controlled trials showed positive results with an increase in VISA-P score or a decrease in VAS or NPPS, respectively. The non-randomized studies confirmed the positive results as well. Among all ten studies no serious adverse events were reported. Based on this limited set of studies, there seems to be some evidence that ST and PT may be effective treatment options to treat pain and to improve function in patients with CPT. To strengthen this recommendation, more research is needed with larger volume studies and randomized controlled studies with long term follow up. LEVEL OF EVIDENCE: IV.

High-volume image-guided injection in the chronic recalcitrant non-insertional patellar tendinopathy: a retrospective case series

Purpose

To evaluate if High-volume Image-guided Injection (HVIGI)-treatment for chronic Patellar tendinopathy (PT) improve function and reduce pain at 16-months follow-up.

Methods

Patients with resistant PT who failed to improve after a three-month eccentric loading program were included in the study. Maximal tendon thickness was assessed with ultrasound. All patients were injected with 10 mL of 0.5% Marcaine, 0.5 mL Triamcinolonacetonid (40 mg/mL) and 40 mL of 0.9% NaCl saline solution under real-time ultrasound-guidance and high pressure. All outcome measures were recorded at baseline and at 16 months. A standardised Heavy Slow Resistance rehabilitation protocol was prescribed after HVIGI-treatment. Clinical outcome was assessed with the Victorian Institute of Sports Assessment-Patella tendon questionnaire (VISA-P) and statistically analyses were performed.

Results

The study included 28 single treatment HVIGI procedures in PT in 23 patients (19 men, 4 women) with a mean age of 30.3 (range 19–52). The mean duration of symptoms before HVIGI was 33 months. The baseline VISA-P score of 43 ± 17 (range 15–76) improved to 76 ± 16 (range 42–95) after 16 months (p < 0.01). Of the 28 HVIGI procedures 12 patients (15 PT) were not satisfied after the initial HVIGI procedure. Of these, 5 patients (5 PT) had additional HVIGI, 2 patients (2 PT) had corticoid injection and 6 patients (8 PT) needed surgery. Of the remaining 11 patients (13 PT), 9 patients had more than a 13-point improvement in the VISA-P score after 16 months.

Conclusions

In this retrospective case-study, only 9 patients (32%) did benefit of a single HVIGI treatment at 16-months and a 33-point significant improvement was seen on the VISA-P score.

Proposal for a Clinical Analysis of Patellar Tendon Pathologies: In Search of Efficient Therapeutic Indications

Development and advances in our understanding of basic sciences such as anatomy, biochemistry, histology, and biomechanics have led to a better knowledge of tendon injuries. Likewise, technological advances in available therapies have conditioned the rise of new therapeutic techniques, turning both diagnosis and therapeutic indications into the foundation of treatment for patellar tendon disorders. Furthermore, we often find no correlation between patellar tendon function and structure, as studied and diagnosed from images taken and referred symptoms. This statement proposes an analytic procedure that ensures a specific therapeutic goal instead of applying a specific drug or therapeutic technique, with the aim of establishing parameters that define the kind of tendinopathy clinicians see, taking into account all conditioning factors that may affect a patellar tendinopathy. These include etiological factors, systemic illnesses affecting tendons, local mechanical causes and clinical presentation, range of clinical presentations, symptom persistence, and pain location, as well as those factors described by echography, with or without the presence of neoangiogenesis and location of the pathology, and magnetic resonance imaging. Diagnosing patellar tendinopathies requires deployment of a complex and thorough assessment process for each individual case and should include all variables that basic sciences have provided. Once a diagnosis has been made, a therapeutic strategy that includes all existing variables should be established. The more precise a diagnosis is, the more selective the treatment options become.

The effectiveness of radial extracorporeal shock wave therapy (rESWT), sham-rESWT, standardised exercise programme or usual care for patients with plantar fasciopathy: study protocol for a double-blind, randomised, sham-controlled trial

Background

Plantar fasciopathy is a common cause of plantar heel pain, with a reported prevalence of up to 10%. The choice of best practice in these patients is debated. Two randomised studies reported that radial extracorporeal shock wave therapy is effective, but a meta-analysis concluded that due to methodological limitations, the evidence is questionable. There are few studies reporting the effect of exercise programs with high-load strength training, despite widespread use. The objective of this placebo-controlled, observer-blinded and partly patient blinded trial is to compare rESWT, sham-rESWT, standardised exercise programme and usual care for alleviating heel pain at 6 and 12 months follow-up.

Methods/design

A double-blind, randomised, sham-controlled trial is conducted at a hospital outpatient clinic of physical medicine and rehabilitation. Patients with chronic (> 3 months) pain due to plantar fasciopathy, aged 18 to 70 years old, are eligible for inclusion in the trial. Patients will be randomly allocated in 1:1 ratio to receive rESWT, sham-rESWT, standardised exercises or usual care. The sample size is estimated to 200 patients, 50 in each group. rESWT or sham-rESWT will be given once a week for 3 weeks. A physiotherapist will supervise the exercises, with a total of 8 sessions over 12 weeks. The patients in the usual care group will receive information, advice and foot orthosis only. All patients, regardless of group, will receive the same information and get an individual customised foot orthosis made by an orthopaedic technician. The primary outcome measure is heel pain intensity during activity in the last week, using a numeric rating scale (NRS, 0 to 10) at the 6 months follow-up adjusted for baseline pain intensity. The secondary outcomes are at the 6- and 12-month follow-up and include Foot Functional Index Revised Short Version (FFI-RS), Patient Global Impression of Change Scale (7-point Likert scale), RAND-12 Health Status Inventory (RAND-12), NRS during rest and NRS during activity (12 months). The patients receiving rESWT/sham-rESWT and the outcome assessor will be blinded to the group assignment.

Discussion

This trial is designed in order to provide results important for future clinical practice.

Trial registration

ClinicalTrials.gov NCT03472989. Registered on 14 March 2018

Patellar tendinopathy outcome predictors in jumping athletes: feasibility of measures for a cohort study

OBJECTIVES

The main aim was to assess feasibility by testing data collection procedures for a cohort study. Measurements validity and reliability were secondary objectives.

DESIGN

Feasibility study.

SETTING

Combination of remote contact, assessment in clinic and biomechanical evaluation.

PARTICIPANTS

36 jumping athletes (female:17, male:19) equally spread between those with patellar tendinopathy, other knee problems and controls.

MAIN OUTCOME MEASURES

Measurements validity, reliability and feasibility.

RESULTS

There was no systematic difference between administration methods for patient reported outcome measures and miscellaneous questions (range of d = -0.32 to 0.26) without any order effect (all p > 0.05) except KOOS-PF (p = 0.02). Questionnaires' inter-session reliability was moderate to excellent (ICCs = 0.68-0.93). Pain maps were 94% matched between methods. Training load recall percentage decreased until week-3 with only 20% maintaining a training diary completing the full 6 weeks. The graded loaded challenge was clinically applicable, biomechanically valid with increasing load through progression and reliable (ICCs = 0.63-0.98).

CONCLUSION

The tested questionnaires were valid and reliable for online use, therefore being suitable for clinical and research purposes. A shorter survey to reduce burden and collecting training load using shorter recall duration should improve feasibility. Biomechanical measures were valid and reliable, and a graded loaded challenge, suitable for further testing, has been defined.

Prolotherapy: Regenerative Medicine for Lateral Epicondylitis

Lateral epicondylitis (LE) is a degenerative disease of the tendons, spurred by repetitive microtrauma leading to an attempt by the body to heal by upregulating local angiogenesis and fibroblast proliferation. Prolotherapy (PT) is the injection of dextrose around the injured tissues to stimulate their spontaneous regeneration. Herein, we have described a case of lateral epicondylitis, diagnosed with clinical and ultrasound (US) examination, where local steroid injections provided relief only for a limited time. We treated the patient with US-guided PT, following which the pain disappeared and the tendon was restored.

In vivo evaluation of human patellar tendon microstructure and microcirculation with diffusion MRI

BACKGROUND

Patellar tendon (PT) microstructure integrity and microcirculation status play a crucial role in the progression of tendinopathy and tendon repair.

PURPOSE

To assess the feasibility and robustness of stimulated-echo based diffusion-weighted MRI with readout-segmented echo-planar imaging (ste-RS-EPI) for noninvasive assessment of microstructure and microcirculation of human PT.

STUDY TYPE

Prospective.

SUBJECTS

Fifteen healthy volunteers.

FIELD STRENGTH/SEQUENCE

PT diffusion tensor imaging (DTI) and intravoxel incoherent motion (IVIM) were acquired with an ste-RS-EPI protocol on a 3T MRI scanner.

ASSESSMENT

Subjects were positioned with their PT at the magic angle. DTI-derived parameters including axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD), and fractional anisotropy (FA) were estimated with b-values of 0 and 800 s/mm² and 12 diffusion directions. IVIM-derived parameters, f _p , D* × f _p , V _b , and D* × V _b were assessed in the central-third and the outer-two thirds of the PT with b-values of 0, 20, 30, 60, 80, 120, 200, 400, and 600 s/mm² in three orthogonal directions.

STATISTICAL TESTS

Paired t-tests were used to evaluate differences in IVIM parameters between the central-third and outer-two thirds regions of the patellar tendon. Paired t-tests and within-subject coefficient of variation were used to assess the intra- and intersession reproducibility of PT DTI and IVIM parameters.

RESULTS

DTI parameters for healthy PT were 1.54 ± 0.09 × 10^-3 mm² /s, 1.01 ± 0.05 × 10^-3 mm² /s, 1.18 ± 0.06 × 10^-3 mm² /s, and 0.30 ± 0.04 for AD, RD, MD, and FA, respectively. Significantly higher (P < 0.05) IVIM parameters f _p and D* × f _p were observed in the outer-two thirds (6.1% ± 2.4% and 95.2 ± 49.6, respectively) compared with the central-third (3.8% ± 2.3% and 48.6 ± 35.2, respectively) of the PT.

DATA CONCLUSION

Diffusion MRI of PT with an ste-RS-EPI protocol is clinically feasible. Both DTI- and IVIM-derived parameters of the PT demonstrated good test-retest reproducibility and interrater reliability.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:780-790.

Tendinopathy: Investigating the Intersection of Clinical and Animal Research to Identify Progress and Hurdles in the Field

Biological treatments, surgical interventions, and rehabilitation exercises have been successfully used to treat tendinopathy, but the development of effective treatments has been hindered by the lack of mechanistic data regarding the pathogenesis of the disease. While insightful, clinical studies are limited in their capacity to provide data regarding the pathogenesis of tendinopathies, emphasizing the value of animal models and cell culture studies to fill this essential gap in knowledge. Clinical pathological findings from imaging studies or histological analysis are not universal across patients with tendinopathy and have not been clearly associated with the onset of symptoms. There are several unresolved controversies, including the cellular changes that accompany the tendinopathic disease state and the role of inflammation. Additional research is needed to correlate the manifestations of the disease with its pathogenesis, with the goal of reaching a field-wide consensus on the pathology of the disease state. Such a consensus will allow standardized clinical practices to more effectively diagnose and treat tendinopathy.

Analgesic Management of Pain in Elite Athletes: A Systematic Review

OBJECTIVE

To identify the prevalence, frequency of use, and effects of analgesic pain management strategies used in elite athletes.

DESIGN

Systematic literature review.

DATA SOURCES

Six databases: Ovid/Medline, SPORTDiscus, CINAHL, Embase, Cochrane Library, and Scopus.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Empirical studies involving elite athletes and focused on the use or effects of medications used for pain or painful injury. Studies involving recreational sportspeople or those that undertake general exercise were excluded.

MAIN RESULTS

Of 70 articles found, the majority examined the frequency with which elite athletes use pain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, anesthetics, and opioids. A smaller set of studies assessed the effect of medications on outcomes such as pain, function, and adverse effects. Oral NSAIDs are reported to be the most common medication, being used in some international sporting events by over 50% of athletes. Studies examining the effects of pain medications on elite athletes typically involved small samples and lacked control groups against which treated athletes were compared.

CONCLUSIONS

Existing empirical research does not provide a sufficient body of evidence to guide athletes and healthcare professionals in making analgesic medication treatment decisions. Based on the relatively robust evidence regarding the widespread use of NSAIDs, clinicians and policymakers should carefully assess their current recommendations for NSAID use and adhere to a more unified consensus-based strategy for multidisciplinary pain management in elite athletes. In the future, we hope to see more rigorous, prospective studies of various pain management strategies in elite athletes, thus enabling a shift from consensus-based recommendations to evidence-based recommendations.

B-mode and power Doppler ultrasonography of the equine suspensory ligament branches: A descriptive study on 13 horses

Ultrasonography is routinely used to achieve the diagnosis of equine suspensory ligament desmopathy. In human medicine, power Doppler ultrasonography has also been found to be useful for the diagnosis of tendon/ligament injuries. The aim of this prospective, pilot study was to assess the presence or absence of power Doppler signal in suspensory ligament branches and compare B-mode findings with power Doppler findings in suspensory ligament branches of lame and non-lame limbs. Thirteen horses were used (eight lame horses, with lameness related to pain in the suspensory ligament branches, and five non-lame horses). Ten lame limbs and 24 sound limbs were assessed by B-mode and power Doppler ultrasonography. The severity of power Doppler signal was scored by two independent readers. The B-mode ultrasonographic examination revealed abnormalities in branches of lame limbs and in branches of sound limbs. Suspensory ligament branches that were considered normal in B-mode showed no power Doppler signal. However, power Doppler signal was detected in suspensory ligament branches that were abnormal in B-mode, both in lame and sound limbs. Power Doppler scores were subjectively higher in suspensory ligament branches of lame limbs and in branches with more severe B-mode changes. Findings supported the use of power Doppler as an adjunctive diagnostic test for lame horses with suspected suspensory desmopathy.

Sport and exercise medicine consultants are reliable in assessing tendon neovascularity using ultrasound Doppler

OBJECTIVE

Several lower limb tendinopathy treatment modalities involve identification of pathological paratendinous or intratendinous neovascularisation to target proposed co-location of painful neoneuralisation. The ability to reliably locate and assess the degree of neovascularity is therefore clinically important. The Modified Ohberg Score (MOS) is frequently used to determine degree of neovascularity, but reliability has yet to be established among Sport and Exercise Medicine (SEM) consultants. This study aims to determine inter-rater and intra-rater reliability of an SEM consultant cohort when assessing neovascularity using the 5-point MOS.

METHOD

Eleven participants (7 male and 4 female) provided 16 symptomatic Achilles and patella tendons. These were sequentially examined using power Doppler (PD) enabled ultrasound (US) imaging by 6 SEM consultants who rated neovascular changes seen using the MOS. Representative digital scan images were saved for rescoring 3 weeks later. Inter-rater and intra-rater reliability of the MOS was examined using intraclass correlation coefficient (ICC) and Kappa Agreement scores.

RESULTS

Neovascular changes were reported in 65.6% of 96 scans undertaken. ICC for inter-rater reliability was 0.86 and Fleiss Kappa 0.52. ICC for intra-rater reliability was 0.95 and Weighted Kappa 0.91.

CONCLUSIONS

Neovascular changes were present in two-thirds of symptomatic tendons. Excellent SEM consultant inter-rater and intra-rater reliability was demonstrated. These findings support the use of PD-enabled US to assess neovascularity by appropriately experienced SEM consultants. Furthermore, future interventional research using a similarly experienced SEM consultant cohort can be undertaken with assurance that assessment of neovascularity will be reliable.

Efficacy and safety of hyaluronic acid (500-730kDa) Ultrasound-guided injections on painful tendinopathies: a prospective, open label, clinical study

BACKGROUND

Tendinopathies are conditions characterized by activity-induced pain, local tenderness and swelling for which a gold standard treatment is not established yet. Hyaluronic Acid (HA) is a key-molecule in several cellular activities and it is normally present in the extra-cellular matrix of tendons and ligaments. Amongst its properties, HA injections may reduce pain and determine disease-modifying effects. This study is an investigator-initiated open-label trial conducted to investigate the efficacy and safety of HA (500-730 kDa) peritendinous injections on pain reduction in patients affected by lateral elbow, Achilles or patellar tendinopathy.

METHODS

A total of 71 tendons (34 with Achilles tendinopathy, 26 with lateral elbow tendinopathy, 11 with patellar tendinopathy) of 62 patients with painful tendinopathy were treated with a cycle of ultrasound-guided peritendinous injections one injection per week for three consecutive weeks. Efficacy assessments included changes in pain intensity measured by Visual Analogue Scale (VAS) at follow-up evaluations were performed 7 (V2), 14 (V3) and 56 days aften first treatment. An Ultrasound (US) assessment was also performed to evaluate changes in tendon thickness and neovascularization. Adverse events were recorded for safety analysis throughout the study. All results were analyzed with descriptive statistics appropriate to the nature of the variables.

RESULTS

Significant reduction in VAS (p<0.001) from baseline was observed in Achilles (-6.16 ± 0.45 cm), patellar (-6.16 ± 0.72 cm) and lateral elbow (-5.33 ± 0.43 cm) tendinopathies. The sagittal thickness decreased significantly from baseline at each endpoint (V3 day 14 and V4 day 56) in each type of tendinopathy analyzed (p<0.05). Neovascularization decreased for each tendons at V3 and V4, except for patellar tendon at V3 V1 (p=0.125). Nevertheless, reduction at V4 compared to baseline remained significant (p=0.016).

CONCLUSIONS

US-guided HA (500-730 kDa) peritendinous injections determine significant pain relief and reduction in tendon thickness and neovascularization in US evaluations. The effect of HA did not show differences regarding the site of affected tendon. The treatment proved to be safe and very well tolerated.

LEVEL OF EVIDENCE

4.

Patellar Tendinopathy: Diagnosis and Treatment

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

Clinical results after ultrasound-guided intratissue percutaneous electrolysis (EPI®) and eccentric exercise in the treatment of patellar tendinopathy

PURPOSE

To investigate the outcome of ultrasound (US)-guided intratissue percutaneous electrolysis (EPI(®)) and eccentric exercise in the treatment of patellar tendinopathy during a long-term follow-up.

METHODS

Forty patients with patellar tendinopathy were prospectively evaluated over a 10-year follow-up period. Pain and function were evaluated before treatment, at 3 months and at 2, 5 and 10 years using the Victorian Institute of Sport Assessment-Patella (VISA-P) score, the Tegner score and Blazina's classification. According to VISA-P score at baseline, patients were also dichotomized into Group 1 (<50 points) and Group 2 (≥50 points). There were 21 patients in Group 1 and 19 in Group 2. Patient satisfaction was measured according to the Roles and Maudsley score.

RESULTS

The VISA-P score improved globally by 41.2 points (p < 0.01) after a mean 4.1 procedures. In Group 1, VISA-P score improved from 33.1 ± 13 to 78.9 ± 14.4 at 3-month and to 88.8 ± 10.1 at 10-year follow-up (p < 0.001). In Group 2, VISA-P score improved from 69.3 ± 10.5 to 84.9 ± 9 at 3-month and to 96.0 ± 4.3 at 10-year follow-up (p < 0.001). After 10 years, 91.2 % of the patients had a VISA-P score >80 points. The same level (80 % of patients) or the Tegner score at no more than one level lower (20 % of patients) was restored, and 97.5 % of the patients were satisfied with the procedure.

CONCLUSION

Treatment with the US-guided EPI(®) technique and eccentric exercises in patellar tendinopathy resulted in a great improvement in knee function and a rapid return to the previous level of activity after few sessions. The procedure has proved to be safe with no recurrences on a long-term basis.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

Patellar Tendinopathy

Context:

Patellar tendinopathy is a common condition. There are a wide variety of treatment options available, the majority of which are nonoperative. No consensus exists on the optimal method of treatment.

Evidence Acquisition:

PubMed spanning 1962-2014.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

The majority of cases resolve with nonoperative therapy: rest, physical therapy with eccentric exercises, cryotherapy, anti-inflammatories, corticosteroid injections, extracorporeal shockwave therapy, glyceryl trinitrate, platelet-rich plasma injections, and ultrasound-guided sclerosis. Refractory cases may require either open or arthroscopic debridement of the patellar tendon. Corticosteroid injections provide short-term pain relief but increase risk of tendon rupture. Anti-inflammatories and injectable agents have shown mixed results. Surgical treatment is effective in many refractory cases unresponsive to nonoperative modalities.

Conclusion:

Physical therapy with an eccentric exercise program is the mainstay of treatment for patellar tendinopathy. Platelet-rich plasma has demonstrated mixed results; evidence-based recommendations on its efficacy cannot be made. In the event that nonoperative treatment fails, surgical intervention has produced good to excellent outcomes in the majority of patients.

Patellar mobility can be reproducibly measured using ultrasound

The present study was performed to examine the reliability of ultrasound in evaluating patellar mobility in the superior-inferior direction. Twelve healthy men volunteered for the study. Patellar mobility in the superior-inferior direction during isometric knee extension contraction with the knee immobilized in a semi-flexed knee brace was measured using ultrasound. Both intra-observer and inter-observer reliability were assessed by intra-class correlation coefficients (ICCs). Bland-Altman analysis was used for assessing agreement between measurements. ICC values were excellent for both intra-observer and inter-observer reliability at 0.97 and 0.93, respectively. In 95 % of measurements, the same observer measured within -0.55 to 0.61 mm, while different observers measured within -0.82 to 0.85 mm. In conclusion, patellar mobility in the superior-inferior direction during an isometric knee extension exercise can be reproducibly measured using ultrasound.

THE LEVEL OF EVIDENCE

VI (basic study of a novel evaluation method).

The mature athlete: aging tendon and ligament

CONTEXT

Aging changes the biology, healing capacity, and biomechanical function of tendons and ligaments and results in common clinical pathologies that present to orthopedic surgeons, primary care physicians, physical therapists, and athletic trainers. A better understanding of the age-related changes in these connective tissues will allow better patient care.

EVIDENCE ACQUISITION

The PubMed database was searched in December 2012 for English-language articles pertaining to age-related changes in tendons and ligaments.

LEVEL OF EVIDENCE

Level 5.

RESULTS

The mature athlete faces challenges associated with age-dependent changes in the rotator cuff, Achilles tendon, lateral humeral epicondylar tendons, quadriceps tendon, and patellar tendon. The anterior cruciate ligament and the medial collateral ligament are the most studied intra-articular and extra-articular ligaments, and both are associated with age-dependent changes.

CONCLUSION

Tendons and ligaments are highly arranged connective tissue structures that maintain joint motion and joint stability. These structures are subject to vascular and compositional changes with increasing age that alter their mechanotransduction, biology, healing capacity, and biomechanical function. Emerging research into the etiology of age-dependent changes will provide further information to help combat the age-related clinical complications associated with the injuries that occur to tendons and ligaments.

Neovascularization prevalence in the supraspinatus of patients with rotator cuff tendinopathy

OBJECTIVE

A high prevalence of neovascularity in lower extremity tendinopathies has been reported. Neovascularity in those with rotator cuff tendinopathy exclusively has not been examined. The objective was to determine the prevalence of neovascularization in patients with rotator cuff tendinopathy compared with asymptomatic controls.

DESIGN

Single-blind cross-sectional study.

SETTING

Research laboratory.

PARTICIPANTS

Participants (n = 40; age = 44.9 years, 23-62 years; 20 females) with rotator cuff tendinopathy (n = 20) but without full-thickness rotator cuff tears, and asymptomatic controls that were age, gender, and hand dominance matched (n = 20) to the patients.

INTERVENTIONS

The participants laying in supine had their shoulder positioned in internal rotation and extension. Ultrasound images were collected of the supraspinatus tendon and subacromial bursae in the transverse and longitudinal planes using a linear transducer in color Doppler mode.

MAIN OUTCOME MEASURES

Images were assessed for neovascularization by 2 trained raters who were blinded to group (rotator cuff tendinopathy or asymptomatic group).

RESULTS

No statistically significant difference in neovascularization was identified between participants with and without rotator cuff tendinopathy (χ = 0.13, df = 1, P = 0.72). Neovascularization was identified in 6 of 20 patients with rotator cuff tendinopathy (30%) and 5 of 20 asymptomatic control participants (25%).

CONCLUSIONS

The authors found no differences in neovascularization rate in patients with rotator cuff tendinopathy (30%) and asymptomatic controls (25%). The study indicates that neovascularization is not related to presence of symptomatic tendinopathy in those with rotator cuff tendinopathy. Neovascularization may not be a relevant sonographic finding to aid the clinical assessment of those with rotator cuff tendinopathy.

New objective findings after whiplash injuries: High blood flow in painful cervical soft tissue: An ultrasound pilot study

Background

The presence of high blood flow in the structurally abnormal and painful regions of tendinosis, but not in the normal pain-free tendons, was recently confirmed by colour Doppler (CD) ultrasound (US). Biopsies from the regions with high blood flow demonstrated the presence of sympathetic and sensitive nerve fibres juxtapositioned to neovessels. Grey-scale US and CD are reliable methods used to evaluate structural homogeneity, thickness, and blood flow in the peripheral tendons. The aim of this study was to utilize CD to qualitatively evaluate for the presence of abnormal high blood flow in paravertebral tissues after whiplash injuries in patients with chronic neck pain.

Methods

Twenty patients with chronic neck pain after whiplash-associated disorder (WAD) and 20 pain-free control subjects were included in the study. The same experienced radiologist performed all grey-scale US and CD examinations.

Results

More regions with high blood flow were observed in the patient group than in the control group. At all levels, the high blood flow pattern was detected at the enthesis of the spinous processes and bilaterally juxtapositioned to the facet joints.

Conclusion

All regions identified by the patients as painful and tender corresponded to the positive high blood flow found during the CD examination.

Implications

These findings document increased blood-flow/neovascularisation at insertions of neck muscles which may indicate that there are pathological neovascularisation with accomanying pain-and sympathetic nerves, similar to what has been found in Achilles-tendinosis. These findings promise that similar treatments that now is successful with Achilles tendinosis, may be effective in the WAD-painful muscle insertions of the neck.

ESWT for tendinopathy: technology and clinical implications

PURPOSE

The general consensus that tendinopathy, at least in the chronic stage, is mainly a degenerative condition and inflammation plays a minor role has led to a shift from treatments that target inflammation towards treatment options that promote regeneration. One of these treatments is extracorporeal shockwave therapy (ESWT), a physical therapy modality that uses pressure waves to treat tendinopathy. This review was undertaken to give an overview of the literature concerning this treatment, and special attention is given to the differences between focused and radial ESWT.

METHODS

A narrative description of wave characteristics, generation methods and in vitro effects of ESWT is given. The literature on ESWT as a treatment for one common tendinopathy, patellar tendinopathy, was systematically reviewed.

RESULTS

Waves that are generated for focused and radial ESWT have very different physical characteristics. It is unclear how these characteristics are related to clinical effectiveness. Studies into the biological effects of ESWT have mainly used focused shockwave therapy, showing a number of effects of shockwaves on biological tissue. The systematic review of studies into the clinical effects of ESWT for patellar tendinopathy showed conflicting evidence for its effectiveness.

CONCLUSION

Physical characteristics of focused and radial waves differ substantially, but effect on clinical effectiveness is unclear. Whereas in vitro studies often show the effects of ESWT on tendon tissue, results of clinical studies are inconsistent. Based on the review of the literature, suggestions are given for the use of ESWT in clinical practice regarding timing and treatment parameters.

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.

Ultrasound-guided sclerosing treatment in patients with patellar tendinopathy (jumper's knee). 44-month follow-up

BACKGROUND

A randomized controlled study has shown good clinical results after treatment with sclerosing injections into the area with neovessels in patients with patellar tendinopathy, but no study has investigated medium- or long-term outcomes.

PURPOSE

This study investigates the effect of sclerosing treatment 44 months (range, 42-47 months) after start of treatment.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients with a diagnosis of jumper's knee and neovascularization corresponding to the painful area were recruited and treated with ultrasound-guided sclerosing injections using polidocanol. Primary outcome was Victorian Institute of Sport Assessment (VISA) score, which was recorded before the start of treatment, after 12 months, and 44 months after the start of the study period.

RESULTS

Twelve of the 29 patients (14 tendons) who were followed up at 44 months had undergone arthroscopic surgery after sclerosing treatment, either to the patellar tendon (n = 6) or for other intra-articular lesions (n = 8). For patients who did not receive additional treatment after the sclerosing injections (n = 23 tendons), VISA score was 55 (range, 28-71) at baseline and 81 (range, 39-100) at 12-month follow-up (P < .001 vs baseline).Their VISA score at 44 months' follow-up was 89 (range, 73-100; P = .047 vs 12 months). For patients who went through arthroscopic tendon surgery, VISA score was 53 (range, 39-71) at baseline and 71 before surgery (range, 48-98; P = .14 vs baseline). Their VISA score at 44 months was 91 (range, 76-100; P = .0.16 vs 12 months; P = .005 vs baseline). For patients who went through non-tendon surgery, VISA score was 45 (range, 15-69) at baseline and 57 (range, 32-95) before surgery (P = .29 vs baseline). Their VISA score at 44 months was 92 (range, 72-100; P = .006 vs before surgery; P < .001 vs baseline).

CONCLUSION

Sclerosing treatment with polidocanol was effective for the majority of the patients. Nevertheless, one-third elected to seek additional treatment through arthroscopic surgery during the 44-month follow-up period.

Skin-derived tenocyte-like cells for the treatment of patellar tendinopathy

BACKGROUND

Recent research of lateral elbow tendinopathy has led to the use of laboratory-amplified tenocyte-like cells.

HYPOTHESIS

Ultrasound-guided injection of autologous skin-derived tendon-like cells are effective compared with other injectable therapies for the treatment of refractory patellar tendinosis.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

From 60 patellar tendons in 46 patients with refractory patellar tendinopathy, a 4-mm skin biopsy was sampled to grow tenocyte-like collagen-producing cells. Patients were allocated into 2 groups: (1) injection with laboratory-prepared, amplified collagen-producing cells derived from dermal fibroblasts and suspended in autologous plasma from centrifuged autologous whole blood or (2) injection with autologous plasma alone. Injections were made into the sites of hypoechogenicity, intrasubstance tears, and fibrillar discontinuity within the patellar tendon. The Victorian Institute of Sport Assessment (VISA) score was used to assess pain, severity, and functional disability. Ultrasound was performed to assess structural and blood flow changes, evaluating 4 criteria: tendon thickness, hypoechogenicity, intrasubstance tears, and neovascularity.

RESULTS

In the cell group, mean VISA scores improved from 44 ± 15 before treatment to 75 ± 17 at 6 months; in the plasma group, from 50 ± 18 to 70 ± 14. Estimated average difference between groups was 8.1, a significantly higher score in the cell group. Patients treated with collagen-producing cells also had significantly faster improvement and a highly significant effect of treatment, with the difference between groups estimated as 2.5 per unit increase in 1/√time. One patient treated with cell therapy had a late rupture and progressed to surgery; histopathology showed normal tendon structure.

CONCLUSION

Ultrasound-guided injection of autologous skin-derived tendon-like cells can be safely used in the short term to treat patellar tendinopathy, with faster response of treatment and significantly greater improvement in pain and function than with plasma alone.

Evidence of accumulated stress in Achilles and anterior knee tendons in elite badminton players

Tendon-related injuries are a major problem, but the aetiology of tendinopathies is unknown. In tendinopathies as well as during unaccustomed loading, intra-tendinous flow can be detected indicating that extensive loading can provoke intra-tendinous flow. The aim of present study is to evaluate the vascular response as indicated by colour Doppler (CD) activity in both the Achilles and patella tendon after loading during high-level badminton matches. The Achilles tendon was subdivided into a mid-tendon, pre-insertional, and insertional region and the anterior knee tendons into a quadriceps-, patella- and tuberositas region. Intra-tendinous flow was measured using both a semi-quantitative grading system (CD grading) and a quantitative scoring system (CF) on colour Doppler. Intra-tendinous flow in the Achilles and anterior knee tendons was examined in fourteen single players before tournament and after 1st and 2nd match, respectively on both the dominant and non-dominant side. All players had abnormal intra-tendinous flow (Colour Doppler ≥ grade 2) in at least one tendon in at least one scan during the tournament. At baseline, only two of the 14 players had normal flow in all the tendons examined. After 1st match, tendencies to higher intra-tendinous flow were observed in both the dominant patella tendon and non-dominant quadriceps tendon (P-values n.s.). After 2nd match, intra-tendinous flow was significant increased in the dominant patella tendon (P = 0.009). In all other locations, there was a trend towards a stepwise increase in intra-tendinous flow. The preliminary results indicate that high amount of intra-tendinous flow was found in elite badminton players at baseline and was increased after repetitive loading, especially in the patella tendon (dominant leg). The colour Doppler measurement can be used to determine changes in intra-tendinous flow after repetitive loading.

Lateral elbow tendinopathy: correlation of ultrasound findings with pain and functional disability

BACKGROUND

Lateral elbow tendinopathy is a common condition often diagnosed by ultrasound. Debate exists regarding which ultrasound findings correlate with disease severity and prognosis.

HYPOTHESIS

Sonographic predictors for tendon healing in patients with lateral elbow tendinopathy can be found by correlating initial ultrasound findings with subsequent changes in pain and functional disability scores after a period of nonoperative management.

STUDY DESIGN

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

METHODS

Sixty-two elbows (34 right, 28 left) in 62 patients (30 male, 32 female) with a clinical diagnosis of lateral elbow tendinopathy underwent sonographic evaluation of the common extensor origin after assessment with a validated outcome measure, the Patient-Rated Tennis Elbow Evaluation (PRTEE). After 6 months of nonoperative standardized treatment (physiotherapy with eccentric loading), the PRTEE questionnaire was repeated.

RESULTS

The mean pretreatment PRTEE was 78 (range, 51-97) and posttreatment score was 29 (range, 0-91). This difference in means was found to be significant (P < .0001). A positive correlation was identified between the presence of a lateral collateral ligament tear (P < .0001) and the size of the largest intrasubstance tear (P < .0001) and poor outcome. A negative correlation was identified with amount of hypoechogenicity (P = .0009). No correlation was found with age, sex, side, duration of symptoms, thickness of tendon, or amount of neovascularity.

CONCLUSION

The size of intrasubstance tears and presence of a lateral collateral ligament tear on ultrasound can be used to assess lateral elbow tendinopathy severity, indicate those who may not respond to nonoperative therapy, and potentially guide more invasive treatment. Those patients with a large intrasubstance tear or tears identified on ultrasound are less likely to respond to nonoperative treatment. Presence of neovascularity has little correlation with change in pain severity or functional disability and may be a poor predictor of prognosis.

New options in the management of tendinopathy

Tendon injuries can be acute or chronic, and caused by intrinsic or extrinsic factors, either alone or in combination. Tendinopathies are a common cause of disability in occupational medicine and account for a substantial proportion of overuse injuries in sports. Tendinopathy is essentially a failed healing response, with haphazard proliferation of tenocytes, abnormalities in tenocytes, with disruption of collagen fibres and subsequent increase in noncollagenous matrix. The scientific evidence base for managing tendinopathies is limited. What may appear clinically as an "acute tendinopathy" is actually a well advanced failure of a chronic healing response in which there is neither histologic nor biochemical evidence of inflammation. In this review we report the new options for the management of tendinopathy, including eccentric exercises, extracorporeal shockwave therapy, injections (intratendinous injections of corticosteroids, aprotinin, polidocanol platelet-rich plasma, autologous blood injection, high-volume injections) and surgery. Open surgery aims to excise fibrotic adhesions, remove areas of failed healing and make multiple longitudinal incisions in the tendon to detect intratendinous lesions, and to restore vascularity and possibly stimulate the remaining viable cells to initiate cell matrix response and healing. New surgical techniques aim to disrupt the abnormal neoinnervation to interfere with the pain sensation caused by tendinopathy. These procedures are intrinsically different from the classical ones in present use, because they do not attempt to address directly the pathologic lesion, but act only to denervate them. They include endoscopy, electrocoagulation, and minimally invasive stripping. Further randomized controlled trials are necessary to clarify better the best therapeutic options for the management of tendinopathy.

The pathogenesis of tendinopathy: balancing the response to loading

Tendons are designed to withstand considerable loads. Mechanical loading of tendon tissue results in upregulation of collagen expression and increased synthesis of collagen protein, the extent of which is probably regulated by the strain experienced by the resident fibroblasts (tenocytes). This increase in collagen formation peaks around 24 h after exercise and remains elevated for about 3 days. The degradation of collagen proteins also rises after exercise, but seems to peak earlier than the synthesis. Despite the ability of tendons to adapt to loading, repetitive use often results in injuries, such as tendinopathy, which is characterized by pain during activity, localized tenderness upon palpation, swelling and impaired performance. Tendon histological changes include reduced numbers and rounding of fibroblasts, increased content of proteoglycans, glycosaminoglycans and water, hypervascularization and disorganized collagen fibrils. At the molecular level, the levels of messenger RNA for type I and III collagens, proteoglycans, angiogenic factors, stress and regenerative proteins and proteolytic enzymes are increased. Tendon microrupture and material fatigue have been suggested as possible injury mechanisms, thus implying that one or more 'weak links' are present in the structure. Understanding how tendon tissue adapts to mechanical loading will help to unravel the pathogenesis of tendinopathy.