Neovascularization in Achilles tendinopathy: have we been chasing a red herring?

Multispectral Optoacoustic Tomography Enables In Vivo Anatomical and Functional Assessment of Human Tendons

Tendon injuries resulting from accidents and aging are increasing globally. However, key tendon functional parameters such as microvascularity and oxygen perfusion remain inaccessible via the currently available clinical diagnostic tools, resulting in disagreements on optimal treatment options. Here, a new noninvasive method for anatomical and functional characterization of human tendons based on multispectral optoacoustic tomography (MSOT) is reported. Healthy subjects are investigated using a hand-held scanner delivering real-time volumetric images. Tendons in the wrist, ankle, and lower leg are imaged in the near-infrared optical spectrum to utilize endogenous contrast from Type I collagen. Morphology of the flexor carpi ulnaris, carpi radialis, palmaris longus, and Achilles tendons are reconstructed in full. The functional roles of the flexor digitorium longus, hallicus longus, and the tibialis posterior tendons have been visualized by dynamic tracking during toe extension-flexion motion. Furthermore, major vessels and microvasculature near the Achilles tendon are localized, and the global increase in oxygen saturation in response to targeted exercise is confirmed by perfusion studies. MSOT is shown to be a versatile tool capable of anatomical and functional tendon assessments. Future studies including abnormal subjects can validate the method as a viable noninvasive clinical tool for tendinopathy management and healing monitoring.

Irreversible Electroporation Improves Tendon Healing in a Rat Model of Collagenase-Induced Achilles Tendinopathy

BACKGROUND

Treatment of painful chronic tendinopathy is challenging, and there is an urgent need to develop new regenerative methods. Irreversible electroporation (IRE) can lead to localized cell ablation by electrical pulses and induce new cell and tissue growth. Previously, the authors' group reported that electroporation-ablated tendons fully regenerated.

PURPOSE

To assess the efficiency of IRE in improving tendon healing using a collagenase-induced Achilles tendinopathy rat model.

STUDY DESIGN

Controlled laboratory study.

METHODS

After screening for the IRE ablation parameters, a collagenase-induced Achilles tendinopathy rat model was used to assess the efficacy of IRE in improving tendon healing via biomechanical, behavioral, histological, and immunofluorescence assessments.

RESULTS

The experiments showed that the parameter of 875 V/cm 180 pulses could ablate most tenocytes, and apoptosis was the main type of death in vitro. In vivo, IRE promoted the healing process of chronic tendinopathy in the Achilles tendon of rats, based on biomechanical, behavioral, and histological assessments. Finally, immunofluorescence results revealed that IRE improved blood supply in the early stages of tendon repair and could potentially reduce neuropathic pain.

CONCLUSION

IRE enhanced tendon tissue healing in a rat model of collagenase-induced Achilles tendinopathy.

CLINICAL RELEVANCE

IRE may as a potential alternative treatment for tendinopathy in clinical usage.

The tendon unit: biochemical, biomechanical, hormonal influences

The current literature has mainly focused on the biology of tendons and on the characterization of the biological properties of tenocytes and tenoblasts. It is still not understood how these cells can work together in homeostatic equilibrium. We put forward the concept of the "tendon unit" as a morpho-functional unit that can be influenced by a variety of external stimuli such as mechanical stimuli, hormonal influence, or pathological states. We describe how this unit can modify itself to respond to such stimuli. We evidence the capability of the tendon unit of healing itself through the production of collagen following different mechanical stimuli and hypothesize that restoration of the homeostatic balance of the tendon unit should be a therapeutic target.

Infrared Thermography, Intratendon Vascular Resistance, and Echotexture in Athletes with Patellar Tendinopathy: A Cross-Sectional Study

Ultrasonographic signs of tendinopathies are an increase in thickness, loss of alignment in collagen fibers and the presence of neovascularization. Nevertheless, analysis of intratendinous vascular resistance (IVR) can be more useful for understanding the physiological state of the tissue. To show thermal, echotextural, and Doppler signal differences in athletes with patellar tendinopathy and controls. Twenty-six athletes with patellar tendinopathy (PT) participants (30.1 years; SD = 9.0 years) and 27 asymptomatic athletes (23.3 years; SD = 5.38 years) were evaluated with thermographic and Doppler ultrasonography (DS). Area of Doppler signals (DS), echotextural parameters (echointensity and echovariation) and IVR were determined by image analysis. The statistical analysis was performed by Bayesian methods and the results were showed by Bayes Factor (BF10: probability of alternative hypothesis over null hypothesis), and Credibility intervals (CrI) of the effect. The absolute differences of temperature (TD) were clearly greater (BF10 = 19) in the tendinopathy group (patients) than in controls. Regarding temperature differences between the affected and healthy limb, strong evidence was found (BF₁₀ = 14) for a higher temperature (effect = 0.53°C; 95% CrI = 0.15°C-0.95°C) and very strong for reduced IVR compared (BF₁₀ = 71) (effect = -0.67; 95% CrI = -1.10 to 0.25). The differences in area of DS (BF₁₀ = 266) and EV (BF₁₀ = 266) were higher in tendinopathy group. TD showed a moderate positive correlation with VISA-P scores (tau-B = .29; 95% CrI = .04-.51) and strong correlation with IVR (r = -.553; 95%CrI = -.75 to .18). Athletes with patellar tendinopathy showed a more pronounced thermal difference, a larger area of Doppler signal, a lower IVR and a moderately higher echovariaton than controls. The correlation between temperature changes and IVR might be related with the coexistence of degenerative and inflammatory process in PT.

Tendon pain - what are the mechanisms behind it?

OBJECTIVES

Management of chronic tendon pain is difficult and controversial. This is due to poor knowledge of the underlying pathophysiology of chronic tendon pain, priorly known as tendinitis but now termed tendinopathy. The objective of this topical review was to synthesize evolving information of mechanisms in tendon pain, using a comprehensive search of the available literature on this topic.

CONTENT

This review found no correlations between tendon degeneration, collagen separation or neovascularization and chronic tendon pain. The synthesis demonstrated that chronic tendon pain, however, is characterized by excessive nerve sprouting with ingrowth in the tendon proper, which corresponds to alterations oberserved also in other connective tissues of chronic pain conditions. Healthy, painfree tendons are devoid of nerve fibers in the tendon proper, while innervation is confined to tendon surrounding structures, such as sheaths. Chronic painful tendons exhibit elevated amounts of pain neuromediators, such as glutamate and substance p as well as up-regulated expression and excitability of pain receptors, such as the glutamate receptor NMDAR1 and the SP receptor NK1, found on ingrown nerves and immune cells. Increasing evidence indicates that mast cells serve as an important link between the peripheral nervous system and the immune systems resulting in so called neurogenic inflammation.

SUMMARY

Chronic painful tendons exhibit (1) protracted ingrowth of sensory nerves (2) elevated pain mediator levels and (3) up-regulated expression and excitability of pain receptors, participating in (4) neuro-immune pathways involved in pain regulation. Current treatments that entail the highest scientific evidence to mitigate chronic tendon pain include eccentric exercises and extracorporeal shockwave, which both target peripheral neoinnervation aiming at nerve regeneration.

OUTLOOK

Potential mechanism-based pharmacological treatment approaches could be developed by blocking promotors of nerve ingrowth, such as NGF, and promoting inhibitors of nerve ingrowth, like semaphorins, as well as blocking glutamate-NMDA-receptor pathways, which are prominent in chronic tendon pain.

Advances in Microscopic Studies of Tendinopathy: Literature Review and Current Trends, with Special Reference to Neovascularization Process

Tendinopathy is a process of chaotic extracellular matrix remodeling followed by increased secretion of enzymes and mediators of inflammation. The histopathological assessment of tendinous tissue is crucial to formulate the diagnosis and establish the severity of tendon degeneration. Nevertheless, the microscopic analysis of tendinous tissue features is often challenging. In this review, we aimed to compare the most popular scales used in tendon pathology assessment and reevaluate the role of the neovascularization process. The following scores were evaluated: the Bonar score, the Movin score, the Astrom and Rausing Score, and the Soslowsky score. Moreover, the role of neovascularization in tendon degeneration was reassessed. The Bonar system is the most commonly used in tendon pathology. According to the literature, hematoxylin and eosin with additional Alcian Blue staining seems to provide satisfactory results. Furthermore, two observers experienced in musculoskeletal pathology are sufficient for tendinopathy microscopic evaluation. The control, due to similar and typical alterations in tendinous tissue, is not necessary. Neovascularization plays an ambiguous role in tendon disorders. The neovascularization process is crucial in the tendon healing process. On the other hand, it is also an important component of the degeneration of tendinous tissue when the regeneration is incomplete and insufficient. The microscopic analysis of tendinous tissue features is often challenging. The assessment of tendinous tissue using the Bonar system is the most universal. The neovascularization variable in tendinopathy scoring systems should be reconsidered due to discrepancies in studies.

Overview of First-Line and Second-Line Pharmacotherapies for Osteoarthritis with Special Focus on Intra-Articular Treatment

Osteoarthritis (OA) can be defined as the result of pathological processes of various etiologies leading to damage to the articular structures. Although the mechanism of degenerative changes has become better understood due to the plethora of biochemical and genetic studies, the drug that could stop the degenerative cascade is still unknown. All available forms of OA therapy are based on symptomatic treatment. According to actual guidelines, comprehensive treatment of OA should always include a combination of various therapeutic options aimed at common goals, which are pain relief in the first place, and then the improvement of function. Local treatment has become more common practice, which takes place between rehabilitation and pharmacological treatment in the hierarchy of procedures. Only in the case of no improvement and the presence of advanced lesions visible in imaging tests, should surgery be considered. Currently, an increasing number of studies are being published suggesting that intra-articular injections may be as effective or even more effective than non-steroidal anti-inflammatory drugs (NSAIDs) and result in fewer systemic adverse events. The most commonly used preparations are hyaluronic acid (HA), glucocorticosteroids (GS), and also platelet-rich plasma (PRP) in recent years. This review aims to present the mechanism of action and clinical effectiveness of different pharmacological options in relieving pain and improving functions in OA as well as the emerging approach in intra-articular treatment with PRP.

Reliability of a New Semi-automatic Image Analysis Method for Evaluating the Doppler Signal and Intratendinous Vascular Resistance in Patellar Tendinopathy

The aim of this study was to determine the intra- and inter-rater reliability of a new semi-automatic image analysis method for quantification of the shape of the Doppler signal and the intratendinous vascular resistance in patellar tendinopathy. Thirty athletes (27.4 y, standard deviation = 8.57 y) with patellar intratendinous vascularity were included in a cross-sectional study (42 tendons analyzed). The intratendinous blood flow was assessed with power Doppler and ImageJ (Version 1.50b, National Institutes of Health, Bethesda, MD, USA) quantification software over a manually selected region of interest. Two blinded observers performed the analysis of the Doppler signal (vascular resistance) and shape descriptors (number of signals, pixel intensity, area, perimeter, major diameter, minor diameter, circularity and solidity). The intraclass correlation coefficient (ICC) was calculated, and the Bland-Altman mean of differences (MoD) and 95% limits of agreement (LoA) were determined. Also, small real differences (SRDs) and the standard error of measurement (SEM) were calculated. Intra-rater reliability was at a maximum for area (ICC = 0.999, 95% confidence interval [CI] = 0.998-0.999) and at a minimum for solidity (ICC = 0.782, 95% CI: 0.682-0.853). The MoD and 95% LoA were very low, and the relative SRD and SEM were below 5.3% and 2%, respectively. The inter-rater reliability was the maximum for area (ICC = 0.993, 95% CI = 0.989-0.996) and the minimum for circularity (ICC = 0.73; 95% CI=0.611-0.817). The MoD and 95% LoA were low, with the SRD and SEM below 6% and 2.2%. The proposed quantitative method for studying the intratendinous Doppler signal in the patellar tendon is reliable and reproducible.

Intraindividual Doppler Flow Response to Exercise Differs Between Symptomatic and Asymptomatic Achilles Tendons

Objective

This study investigated intraindividual differences of intratendinous blood flow (IBF) in response to running exercise in participants with Achilles tendinopathy.

Design

This is a cross-sectional study.

Setting

The study was conducted at the University Outpatient Clinic.

Participants

Sonographic detectable intratendinous blood flow was examined in symptomatic and contralateral asymptomatic Achilles tendons of 19 participants (42 ± 13 years, 178 ± 10 cm, 76 ± 12 kg, VISA-A 75 ± 16) with clinically diagnosed unilateral Achilles tendinopathy and sonographic evident tendinosis.

Intervention

IBF was assessed using Doppler ultrasound “Advanced Dynamic Flow” before (Upre) and 5, 30, 60, and 120 min (U5–U120) after a standardized submaximal constant load run.

Main Outcome Measure

IBF was quantified by counting the number (n) of vessels in each tendon.

Results

At Upre, IBF was higher in symptomatic compared with asymptomatic tendons [mean 6.3 (95% CI: 2.8–9.9) and 1.7 (0.4–2.9), p < 0.01]. Overall, 63% of symptomatic and 47% of asymptomatic Achilles tendons responded to exercise, whereas 16 and 11% showed persisting IBF and 21 and 42% remained avascular throughout the investigation. At U5, IBF increased in both symptomatic and asymptomatic tendons [difference to baseline: 2.4 (0.3–4.5) and 0.9 (0.5–1.4), p = 0.05]. At U30 to U120, IBF was still increased in symptomatic but not in asymptomatic tendons [mean difference to baseline: 1.9 (0.8–2.9) and 0.1 (-0.9 to 1.2), p < 0.01].

Conclusion

Irrespective of pathology, 47–63% of Achilles tendons responded to exercise with an immediate acute physiological IBF increase by an average of one to two vessels (“responders”). A higher amount of baseline IBF (approximately five vessels) and a prolonged exercise-induced IBF response found in symptomatic ATs indicate a pain-associated altered intratendinous “neovascularization.”

Evidence for the use of PRP in chronic midsubstance Achilles tendinopathy: A systematic review with meta-analysis

BACKGROUND

Platelet-rich plasma (PRP) injections have been proposed as an additional therapy in the treatment of chronic midsubstance Achilles tendinopathy (AT). The use of PRP injections as pharmacological treatment added to a conservative approach has gained growing interest, but the efficacy remains highly debated. The varying methodological quality of the available studies may contribute to these contradictory results. The aim of this systematic review with meta-analysis was to establish the existing evidence of PRP injections for chronic midsubstance AT on the functional outcome, with a risk of bias assessment of each included study.

METHODS

According to the PRISMA guidelines systematic searches were performed in Embase, the Cochrane library and Pubmed on June 12, 2020 for relevant literature. Only clinical trials comparing PRP injections with placebo, additional to an eccentric training program, in midsubstance AT were included. The primary outcome was Victorian Institute of Sport Assessment - Achilles (VISA-A) score at 3, 6 and 12 months post-injection. Risk of bias was assessed using the Cochrane risk-of-bias tool for randomized trials (Rob 2). As secondary outcome we assessed reported changes in tendon structure after PRP injections.

RESULTS

A total of 367 studies were identified with the initial database search. Finally, four randomized controlled trials (RCTs) met inclusion criteria for systematic review and meta-analysis with data of 170 patients available for pooling. Results showed no difference in clinical outcome between the PRP and placebo group at different points in time using the VISA-A score as outcome parameter (3 months 0.23 (CI -0.45, 0.91); 6 months 0.83 (CI -0.26, 1.92); 12 months 0.83 (CI -0.77, 2.44)). The bias analysis showed a low or intermediate risk of bias profile for all studies which supports the good methodological quality of each included article. Finally, it is unclear whether PRP injections cause an improvement in tendon structure. However, no direct relationship between tendon structure and clinical presentation of AT could be found.

CONCLUSION

PRP has no clear additional value in management of chronic midsubstance Achilles tendinopathy and therefore should not be used as a first-line treatment option.

Image-guided intervention in the management of chronic patellar tendinopathy with calcification: a three-pronged approach

Patellar tendinopathy is a common cause of knee pain and functional impairment in athletes. It is commonly managed using conservative measures such as physiotherapy, but cases that are refractory to such treatment may require a more invasive approach. Various forms of image-guided injection therapy have been described in the literature. We present a case of successful treatment of chronic patellar tendinopathy with calcification with the first reported use of a three-pronged image-guided approach, consisting of dry needling, high volume image-guided injection (but at a reduced dose) and barbotage applied in a single sitting. The patient reported resolution of symptoms persisting to 1 year postprocedure. We suggest that this management option, if supported by further positive research findings, could be used in the future in the management of certain cases of patellar tendinopathy with calcification where conservative measures have failed.

Doppler Flow Response Following Running Exercise Differs Between Healthy and Tendinopathic Achilles Tendons

Background

The relationship between exercise-induced intratendinous blood flow (IBF) and tendon pathology or training exposure is unclear.

Objective

This study investigates the acute effect of running exercise on sonographic detectable IBF in healthy and tendinopathic Achilles tendons (ATs) of runners and recreational participants.

Methods

48 participants (43 ± 13 years, 176 ± 9 cm, 75 ± 11 kg) performed a standardized submaximal 30-min constant load treadmill run with Doppler ultrasound “Advanced dynamic flow” examinations before (U_pre) and 5, 30, 60, and 120 min (U₅-U₁₂₀) afterward. Included were runners (>30 km/week) and recreational participants (<10 km/week) with healthy (H_run, n = 10; H_rec, n = 15) or tendinopathic (T_run, n = 13; T_rec, n = 10) ATs. IBF was assessed by counting number [n] of intratendinous vessels. IBF data are presented descriptively (%, median [minimum to maximum range] for baseline-IBF and IBF-difference post-exercise). Statistical differences for group and time point IBF and IBF changes were analyzed with Friedman and Kruskal-Wallis ANOVA (α = 0.05).

Results

At baseline, IBF was detected in 40% (3 [1–6]) of H_run, in 53% (4 [1–5]) of H_rec, in 85% (3 [1–25]) of T_run, and 70% (10 [2–30]) of T_rec. At U₅ IBF responded to exercise in 30% (3 [−1–9]) of H_run, in 53% (4 [−2–6]) of H_rec, in 70% (4 [−10–10]) of T_run, and in 80% (5 [1–10]) of T_rec. While IBF in 80% of healthy responding ATs returned to baseline at U₃₀, IBF remained elevated until U₁₂₀ in 60% of tendinopathic ATs. Within groups, IBF changes from U_pre-U₁₂₀ were significant for H_rec (p < 0.01), T_run (p = 0.05), and T_rec (p < 0.01). Between groups, IBF changes in consecutive examinations were not significantly different (p > 0.05) but IBF-level was significantly higher at all measurement time points in tendinopathic versus healthy ATs (p < 0.05).

Conclusion

Irrespective of training status and tendon pathology, running leads to an immediate increase of IBF in responding tendons. This increase occurs shortly in healthy and prolonged in tendinopathic ATs. Training exposure does not alter IBF occurrence, but IBF level is elevated in tendon pathology. While an immediate exercise-induced IBF increase is a physiological response, prolonged IBF is considered a pathological finding associated with Achilles tendinopathy.

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.

Correlation between smoking and neovascularization in biceps tendinopathy: a functional preoperative and immunohistochemical study

Aims

The purpose of this study was to investigate whether smoking is associated with neovascularization in the tendinopathy of the long head of the biceps tendon (LHBT).

Methods

The study included 40 consecutive patients who underwent arthroscopic biceps tenotomy/tenodesis due to chronic biceps tendinopathy and divided into three groups: (1) non-smokers, (2) former smokers, (3) smokers. LHBT tissue samples were stained with H&E, Alcian blue and Trichrome staining. Immunohistochemical examination was performed using anti-CD31 and anti-CD34. The neovessel density score (NDS) was scored by Bonar criteria.

Results

The mean period of smoking was 15.50 years with an average number of 24 cigarettes/day in the former smokers and 21.69 years with an average number of 15 cigarettes/day in the active smokers. The mean NDS was 2.23/3 in non-smokers, whereas it was 1.60/3 in former smokers and 1.31/3 in active smokers. The mean American Shoulder and Elbow Surgeons score equaled 46 in never smoked patients, 43.60 in former smokers, and 41.46 in active smokers. In the patients with smoking history, the disorganized tendinous tissue islands were avascular and composed of compact acidic polysaccharides and mucopolysaccharides. We observed negative correlation between the NDS and the smoking indexes, including cigarettes per day (p = 0.0150), smoking years (p = 0.0140), pack-years (p = 0.0088).

Conclusion

In conclusion, the present study revealed that smoking impairs the vascularization of the biceps tendon in chronic tendinopathy. Clinically, we observed a negative correlation between smoking and neovascularization. Furthermore, there was no correlation between neovascularization and functional preoperative status.

Evaluation of Postoperative Changes in Patellar and Quadriceps Tendons after Total Knee Arthroplasty-A Comprehensive Analysis by Shear Wave Elastography, Power Doppler and B-mode Ultrasound

RATIONALE AND OBJECTIVES

Up to now, the diagnosis of tendinopathies is based on conventional B-mode-ultrasound (B-US), Power Doppler-ultrasound (PD-US), and magnetic resonance imaging. In the past decade, Shear Wave Elastography (SWE) has been introduced in tendon imaging, for example in athletes or patients suffering from tendinopathy. SWE allows real-time quantification of tissue stiffness, and, by this, the assessment of the mechanical properties of a tendon and its changes during acute disease and tendon healing. So far there are no ultrasound-based studies that have evaluated postoperative tendon changes, anatomical and mechanical properties and tendon healing of the patellar, and quadriceps tendon following Total Knee Arthroplasty (TKA). The purpose of this prospective study was two-fold: first to analyze morphologic, vascular, and mechanical properties of patellar and quadriceps tendons in patients following TKA; and, second to evaluate possible changes thereof and their visibility in the course of time.

MATERIALS AND METHODS

Observational cross-sectional, IRB-approved study in 63 postoperative patients with a total of 76 total knee arthroplasties (50 unilateral, 13 bilateral) and 50 nonoperated knees for comparison, resulting in 152 postoperative patellar- and quadriceps and 100 nonoperated patellar- and quadriceps-tendons for comparative analysis. For further examination, we divided the 63 patients into two groups according to the duration since surgery (group A < 24 months; group B > 24 months). All patients completed a standardized questionnaire, furthermore the Knee Society score and the Knee Society function score. The amount of experienced pain was assessed using the ordinal numeric rating scale and the presence of anterior knee pain was examined. Subsequently every participant underwent a standardized multimodal ultrasound protocol consisting of B-US, PD-US, and SWE of the left and right patellar and quadriceps tendons.

RESULTS

Using the different US-modalities, operated patellar, and quadriceps tendons (n = 152) were significantly more frequent classified as pathological (B-US) (p < 0.001), the mean Ohberg score was significantly higher (PD-US) (p < 0.001), and the tendons were significantly softer (SWE) than their nonoperated counterparts (n = 100). Mean SWE-value of postoperative patellar tendons was 45.66 ± 14.84 kPa versus 60.08 ± 19.13 kPa in nonoperated knees (p < 0.001). Mean SWE-value of postoperative quadriceps tendons was 35.73 ± 15.66 kPa versus 52.69 ± 16.20 kPa in nonoperated knees (p < 0.001). Comparing the two postoperative groups (group A and B), we recognized a significant decrease of pathologically classified patellar and quadriceps tendons (B-US and PD-US) in group B. The early postoperatively reduced SWE values slightly increased during the course of time.

CONCLUSION

After TKA, patellar, and quadriceps tendons show significant measurable alterations in B-US, PD-US, and SWE. Especially a significant decrease of tendon stiffness in operated knees, as assessed by SWE, might be a surrogate marker for changed mechanical properties. These alterations improve, the longer ago the surgery was. The quantitative information obtained by SWE could be of particular interest in follow-up and therapy monitoring after TKA. Knowledge about tendon stiffness and it's varieties in different population groups (e.g. athletes, elderly, postoperative patients) is crucial to sonographically rate a tendon as "healthy" or "diseased."

Autologous bone marrow expanded mesenchymal stem cells in patellar tendinopathy: protocol for a phase I/II, single-centre, randomized with active control PRP, double-blinded clinical trial

Introduction

Patellar tendon overuse injuries are common in athletes. Imaging may show a change in tissue structure with tendon thickening and disruption of the intratendinous substance. We wish to test the hypothesis that both autologous bone marrow expanded mesenchymal stem cells and autologous leukocyte-poor platelet-rich plasma (LP-PRP) implanted into the area of the disrupted tendinopathic patellar tendon will restore function, but tendon regeneration tissue will only be observed in the subjects treated with autologous bone marrow expanded mesenchymal stem cells.

Methods and analysis

This is a single-centre, pilot phase I/II, double-blinded clinical trial with randomisation with active control. Twenty patients with a diagnosis of patellar tendinopathy with imaging changes (tendon thickening and disruption of the intratendinous substance at the proximal portion of the patellar tendon) will be randomised in a 1:1 ratio to receive a local injection of either bone-marrow autologous mesenchymal stem cells (MSC), isolated and cultured under GMP at The Institute of Biology and Molecular Genetics (IBGM) (Spain) or P-PRP. The study will have two aims: first, to ascertain whether a clinically relevant improvement after 3, 6 and 12 months according to the visual analogue scale (VAS), Victorian Institute of Sport Assessment for patellar tendons (VISA-P) and dynamometry scales (DYN) will be achieved; and second, to ascertain whether the proposed intervention will restore tendon structure as determined by ultrasonography (US), Doppler ultrasonography (DUS), and innovative MRI and ultrasound techniques: Magnetic Resonance T2 FAT SAT (UTE, Ultrashort Echo TE) sequence and Ultrasound Tissue Characterization (UTC). Patients who are randomised to the P-PRP treatment group but do not achieve a satisfactory primary endpoint after 6 months will be offered treatment with MSC.

Trial registration

NCT03454737.

Patellar Tendon Strain Associates to Tendon Structural Abnormalities in Adolescent Athletes

High mechanical strain is thought to be one of the main factors for the risk of tendon injury, as it determines the mechanical demand placed upon the tendon by the working muscle. The present study investigates the association of tendon mechanical properties including force, stress and strain, and measures of tendon micromorphology and neovascularization, which are thought to be indicative of tendinopathy in an adolescent high-risk group for overuse injury. In 16 adolescent elite basketball athletes (14–15 years of age) we determined the mechanical properties of the patellar tendon by combining inverse dynamics with magnetic resonance and ultrasound imaging. Tendon micromorphology was determined based on a spatial frequency analysis of sagittal plane ultrasound images and neovascularization was quantified as color Doppler area. There was a significant inverse relationship between tendon strain and peak spatial frequency (PSF) in the proximal tendon region (r = −0.652, p = 0.006), indicating locally disorganized collagen fascicles in tendons that are subjected to high strain. No such associations were present at the distal tendon site and no significant correlations were observed between tendon force or stress and tendon PSF as well as between tendon loading and vascularity. Our results suggest that high levels of tendon strain might associate to a micromorphological deterioration of the collagenous network in the proximal patellar tendon, which is also the most frequent site affected by tendinopathy. Neovascularization of the tendon on the other hand seems not to be directly related to the magnitude of tendon loading and might be a physiological response to a high frequency of training in this group. Those findings have important implications for our understanding of the etiology of tendinopathy and for the development of diagnostical tools for the assessment of injury risk.

Power Doppler Ultrasound Findings before and after Focused Extracorporeal Shock Wave Therapy for Achilles Tendinopathy: A Pilot Study on Pain Reduction and Neovascularization Effect

Extracorporeal shock wave therapy (ESWT) has been found to have a positive effect in the treatment of pain in Achilles tendinopathy, although the exact mechanism is not yet completely understood. Among the mechanisms suggested to underlie ESWT effects are direct stimulation of healing, neovascularization and direct suppressive effects on nociceptors and hyperstimulation, which would block the gate-control system. The neovascularization observed in flogistic tissue is associated with stimulated nerve fibers around tendons and induces a painful condition. The objectives of the present study were to evaluate the effect of ESWT on pain and function in patients with non-insertional Achilles tendinopathy (NIAT) and to assess the neovascularization phenomenon using power Doppler ultrasound (PDU). Twelve patients with NIAT underwent five sessions of focused ESWT over 5 wk. Outcome measures were the visual analogue scale, the Victorian Institute of Sport Assessment-Achilles questionnaire and active dorsiflexion and plantar flexion ankle articular range of motion. Moreover, the patients' clinical impressions of treatment results after ESWT were investigated using the Roles and Maudsley score. Patients were assessed at baseline and 1 and 3 mo after treatment. They had a significant reduction in pain with improvement of arthrokinematic motion and functionality and a positive clinical impression of treatment outcome (50% of patients considered their clinical picture as good/excellent after 3 mo). However, the pulse Doppler ultrasound exam did not reveal neovascularization in 91.7% of the patients 1 and 2 mo after focused ESWT, and in some patients there was a reduction in blood vessels related to flogistic processes. The present observational study confirmed the efficacy of ESWT in pain reduction in NIAT, with a higher degree of patient satisfaction, although doubt persists over the neovascularization effect on the Achilles tendons treated.

Platelet-Rich Plasma Diffusion in Achilles Tendon: Relationship with Therapeutic Outcomes

OBJECTIVE

The therapeutic efficacy of platelet-rich plasma in the treatment of Achilles tendinopathy is controversial. Among the variables which can explain the discrepant results, little attention has been paid to the distribution of platelet-rich plasma inside the tendon. The aim of the present study was to evaluate whether this factor is related to the clinical outcome of treatment.

SUBJECTS AND METHODS

Forty patients suffering from mid-portion Achilles tendinopathy were studied. At baseline, pain and function were measured by means of a visual analogue scale and the Victorian Institute of Sport Assessment-Achilles questionnaire. Thereafter, an ultrasound examination was performed, and platelet-rich plasma was injected. Immediately after injection, the plasma distribution was assessed visualizing the material in the tendon. The patients were re-evaluated at 3 and 6 months, computing pain and function values and the percentage of satisfactory outcomes in relation to the distance reached by the plasma from the point of injection.

RESULTS

The diffusion inside the tendon was longitudinal in all cases and cross-sectional only in 9. The mean distance from the tip of the needle increased significantly according to the severity of tendon damage. At follow-up, no relationship was found between plasma diffusion and clinical outcomes.

CONCLUSIONS

Platelet-rich plasma diffusion has no effect on clinical outcome, which mainly depends on the metabolic activation of the whole structure of the tendon.

Extracellular matrix supports healing of transected rabbit Achilles tendon

Extracellular matrix (ECM) has been intensively used in cardio surgery. The main goal of this research was to determine if Achilles tendon healing could be promoted by applying extracellular matrix scaffold (CorMatrix®, USA). Sixteen (n = 16) New Zealand white mature rabbits (Oryctolagus cuniculus) were randomly allocated into two groups. Following complete surgical transection, rabbits in group A (ECM applied) (n = 8) had their Achilles tendons reconstructed using both, nylon suture and extracellular matrix scaffold, whereas in group B (without ECM) the tendons were reconstructed using nylon suture only. After four weeks, the rabbits were euthanized and tendon samples harvested and stained with hematoxylin eosin, Mallory, and Gomory and subsequently histologically analyzed according to modified Bonnar scale. Group B had significantly stronger inflammatory response, including abundant cell infiltration and neovascularization. In group A collagen fibers were predominantly found, whereas in group B reticular fibers were more abundant. Extracellular matrix scaffold has been found to have the real potential for promoting tendon healing through accelerating collagen formation, which is crucial for restoring biomechanical properties of a tendon, decreasing peritendineous adhesion formation, and reducing inflammatory edema and subsequently pain.

In Achilles tendinopathy, the neovascularization, detected by contrast-enhanced ultrasound (CEUS), is abundant but not related to symptoms

PURPOSE AND HYPOTHESIS

Mid-portion Achilles tendinopathy is characterized by a proliferation of small vessels, called neovascularization, which can be demonstrated by power Doppler sonography (PD). Neovascularization can be correlated with diagnosis and consequent therapies focused on vascular supply. Published data regarding the relationship between neovascularisation and symptoms, such as pain and disability, are contradictory. The hypothesis that contrast-enhanced ultrasound (CEUS) could detect with more sensibility than PD the new vessel ingrowth in human degenerated Achilles tendons and therefore the correlation of neovascularization with pain and disability, was evaluated.

METHODS

Thirty consecutive patients of recalcitrant Achilles tendinopathy were studied with ultrasound greyscale (US), PD, CEUS and magnetic resonance imaging. Neovascularization was recorded as percentage on the whole extension of examined area. The vascularization time was recorded as venous and arterial type. Imaging data were classified both concurrently with the examination and in a secondary blinded assessment; any difference in the subjective assessment was discussed and a consensus view formed. Pain and disability were assessed by Western Ontario McMaster Universities Arthritis Index (WOMAC) and EuroQuality of life 5-dimension-5-level questionnaire and visual analogue scale (EQ-VAS). All results were analysed with suitable statistical methods.

RESULTS

76.7% of cases were degenerated; 23.3% had also partial discontinuity of the fibres. PD detected vascularization in 54% of cases, whereas CEUS in 83% of cases: in 13 cases, PD did not detect vascularization. The vascularization time was rapid (< 20 s, arterial type) in 60% of cases. WOMAC pain mean value is 6.4 and SD 3.4; WOMAC total score mean value is 21.6 and SD 12.8. EQ-VAS mean value is 56 and SD 18.3. No statistically significant correlation emerged between vascularization and pain/disability.

CONCLUSIONS

CEUS showed a greater ability to detect neovessels than PD in chronic Achilles tendinopathies. Nevertheless in 30 consecutive tendinopathies, no correlation between pain/disability and neovascularization was found: the role of multiple neovessels continue to be unclear. The possibility to discriminate arterial from venous vessels ('vascularization time') could be useful to understand the pathophysiology of tendinopathies and its healing process.

STUDY TYPE

Diagnostic study.

LEVEL OF EVIDENCE

II.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

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

Minimally Invasive Achilles Tendon Stripping for the Management of Tendinopathy of the Main Body of the Achilles Tendon

Achilles tendinopathy is a common cause of disability. New nerves fibers grow from the paratenon into the Achilles tendon, and they could play a central role in the development of pain. We report the results of minimally invasive Achilles tendon stripping for Achilles tendinopathy in 47 active patients. The Victorian Institute of Sports Assessment-Achilles questionnaire score improved from 53.8 preoperatively to 85.3 postoperatively (p < .001). After a mean follow-up period of 40.5 months, 41 patients had resumed sporting activities at an average of 3.5 months postoperatively. A sural nerve injury was recorded in 5 patients (10.6%), and all 5 complications occurred during the first 12 cases. As a result, the technique was slightly modified, and no sural nerve neuropathy was observed subsequently. One superficial infection (2.1%) was recorded. Minimally invasive Achilles tendon stripping seems to be an effective, technically simple, and inexpensive treatment of Achilles tendinopathy. Further randomized controlled trials involving more patients are needed to confirm these outcomes.

Reliability of Evaluating Achilles Tendon Vascularization Assessed With Doppler Ultrasound Advanced Dynamic Flow

OBJECTIVES

The reliability of quantifying intratendinous vascularization by high-sensitivity Doppler ultrasound advanced dynamic flow has not been examined yet. Therefore, this study aimed to investigate the intraobserver and interobserver reliability of evaluating Achilles tendon vascularization by advanced dynamic flow using established scoring systems.

METHODS

Three investigators evaluated vascularization in 67 recordings in a test-retest design, applying the Ohberg score, a modified Ohberg score, and a counting score. Intraobserver and interobserver agreement for the Ohberg score and modified Ohberg score was analyzed by the Cohen κ and Fleiss κ coefficients (absolute), Kendall τ b coefficient, and Kendall coefficient of concordance (W; relative). The reliability of the counting score was analyzed by intraclass correlation coefficients (ICC) 2.1 and 3.1, the standard error of measurement (SEM), and Bland-Altman analysis (bias and limits of agreement [LoA]).

RESULTS

Intraobserver and interobserver agreement (absolute/relative) ranged from 0.61 to 0.87/0.87 to 0.95 and 0.11 to 0.66/0.76 to 0.89 for the Ohberg score and from 0.81 to 0.87/0.92 to 0.95 and 0.64 to 0.80/0.88 to 0.93 for the modified Ohberg score, respectively. The counting score revealed an intraobserver ICC of 0.94 to 0.97 (SEM, 1.0-1.5; bias, -1; and LoA, 3-4 vessels). The interobserver ICC for the counting score ranged from 0.91 to 0.98 (SEM, 1.0-1.9; bias, 0; and LoA, 3-5 vessels).

CONCLUSIONS

The modified Ohberg score and counting score showed excellent reliability and seem convenient for research and clinical practice. The Ohberg score revealed decent intraobserver but unexpected low interobserver reliability and therefore cannot be recommended.

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

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

Spatiotemporal variations in gene expression, histology and biomechanics in an ovine model of tendinopathy

Flexor tendinopathy is a common problem affecting humans and animals. Tendon healing is poorly understood and the outcomes of conservative and surgical management are often suboptimal. While often considered a localized injury, recent evidence indicates that in the short term, tendinopathic changes are distributed widely throughout the tendon, remote from the lesion itself. Whether these changes persist throughout healing is unknown. The aim of this study was to document gene expression, histopathological and biomechanical changes that occur throughout the superficial digital flexor tendon (SDFT) up to 16 weeks post-injury, using an ovine surgical model of tendinopathy. Partial tendon transection was associated with decreased gene expression for aggrecan, decorin, fibromodulin, tissue inhibitors of metalloproteinases (TIMPS 1, 2 and 3), collagen I and collagen II. Gene expression for collagen III, lumican and matrix metalloproteinase 13 (MMP13) increased locally around the lesion site. Expression of collagen III and MMP13 decreased with time, but compared to controls, collagen III, MMP13 and lumican expression remained regionally high throughout the study. An increase in TIMP3 was observed over time. Histologically, operated tendons had higher pathology scores than controls, especially around the injured region. A chondroid phenotype was observed with increased cellular rounding and marked proteoglycan accumulation which only partially improved with time. Biomechanically, partial tendon transection resulted in a localized decrease in elastic modulus (in compression) but only at 8 weeks postoperatively. This study improves our understanding of tendon healing, demonstrating an early ‘peak’ in pathology characterized by altered gene expression and notable histopathological changes. Many of these pathological changes become more localized to the region of injury during healing. Collagen III and MMP13 expression levels remained high close to the lesion throughout the study and may reflect the production of tendon tissue with suboptimal biomechanical properties. Further studies evaluating the long-term response of tendon to injury (6–12 months) are warranted to provide additional information on tendon healing and provide further understanding of the mechanisms underlying the pathology observed in this study.

The effect of sclerotherapy and prolotherapy on chronic painful Achilles tendinopathy-a systematic review including meta-analysis

Chronic painful Achilles tendinopathy (AT) is a common disorder among athletes. Sclerotherapy (ST) and prolotherapy (PT) are two promising options among the numerous other conservative therapies. As their efficacy and potential adverse effects (AE) are still unclear, we systematically searched, analyzed, and synthesized the available literature on ST and PT for treating AT. Electronic databases, Google Scholar and articles' reference lists were searched according to PRISMA guidelines. Eligibility criteria were set up according to the PICOS-scheme including human and animal studies. Three authors independently reviewed the results and evaluated methodological quality (Coleman Methodology Score and Cochrane Risk of Bias Assessment). The initial search yielded 1104 entries. After screening, 18 articles were available for qualitative synthesis, six of which were subjected to meta-analysis. The mean Coleman Score of the 13 human studies was 50. Four RCTs were ranked as having a low risk of selection bias. Three of those reported a statistically significant drop in the visual analog scale (VAS) score, one a significant increase in the VISA-A Score. 12 of 13 human studies reported positive results in achieving pain relief and patient satisfaction, whereas only one study's finding differed. Meta-analysis revealed an unambiguous result in favor of the intervention (weighted mean difference D=-4.67 cm, 95% CI -5.56 to -3.76 cm [P<.001]). Only one serious AE and two minor AEs were reported in the entire literature. This systematic review suggests that ST and PT may be effective treatment options for AT and that they can be considered safe. Long-term studies and RCTs are still needed to support their recommendation.

Topical polidocanol application in combination with static stretching in tendinopathies: a prospective pilot study

BACKGROUND

Highly operator-based injection therapy with vasosclerosing and anesthetic polidocanol is used for tendinopathies. This pilot-study evaluates the topical application of polidocanol gel.

METHODS

Prospective case series. 39 patients with tendinopathies (14 Achilles, 14 patella, 11 wrist extensors) with a symptom duration > 6 months were included. Polidocanol and static stretching were the therapy in the first 2 weeks, while static stretching was continuously performed for 6 months. Clinical outcome was evaluated with VISA-A, VISA-P and DASH Scores and sonographically with B-Mode (B-Mode), Power Doppler (PD) and Shearwave Elastography (SWE).

RESULTS

22 patients clinically improved (>+10 score points), 11 patients were without improvement (<+ 10) and 1 patient worsened during 6 months. The VISA-A Score increased in average 19 points from 56 to 75 (p< 0.01), VISA-P Score increased 13 points from 59 to 72 (p< 0,01) and the DASH-Score decreased 20 points from 40 to 20 (p< 0,01). SWE correlates better than B-Mode or PD with symptom improvement.

CONCLUSION

The combination of static training and topical polidocanol application seems to be successful in the treatment of tendinopathies. Further RCT studies need to evaluate the efficiency of topical polidocanol application. SWE is a more sensitive tool to describe symptom development than PD or B-Mode.

LEVEL OF EVIDENCE

IV.

Acute effect of running exercise on physiological Achilles tendon blood flow

Sonographically detectable intratendinous blood flow (IBF) is found in 50%-88% of Achilles tendinopathy patients as well as in up to 35% of asymptomatic Achilles tendons (AT). Although IBF is frequently associated with tendon pathology, it may also represent a physiological regulation, for example, due to increased blood flow in response to exercise. Therefore, this study aimed to investigate the acute effects of a standardized running exercise protocol on IBF assessed with Doppler ultrasound (DU) "Advanced dynamic flow" in healthy ATs. 10 recreationally active adults (5 f, 5 m; 29±3 years, 1.72±0.12 m, 68±16 kg, physical activity 206±145 minute/wk) with no history of AT pain and inconspicious tendon structure performed 3 treadmill running tasks on separate days (M1-3) with DU examinations directly before and 5, 30, 60, and 120 minutes after exercise. At M1, an incremental exercise test was used to determine the individual anaerobic threshold (IAT). At M2 and M3, participants performed 30- minute submaximal constant load tests (CL₁ /CL₂ ) with an intensity 5% below IAT. IBF in each tendon was quantified by counting the number of vessels. IBF increased in five ATs from no vessels at baseline to one to four vessels solely detectable 5 minutes after CL₁ or CL₂ . One AT had persisting IBF (three vessels) throughout all examinations. Fourteen ATs revealed no IBF at all. Prolonged running led to a physiological, temporary appearance of IBF in 25% of asymptomatic ATs. To avoid exercise-induced IBF in clinical practice, DU examinations should be performed after 30 minutes of rest.

Midsubstance Tendinopathy, Surgical Management

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

Non-insertional Achilles tendinopathy

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

[Tendinopathies of the foot and ankle : Evidence for the origin, diagnostics and therapy]

Tendinopathies of the foot and ankle result in substantial impairment of the mobility of patients and have a high clinical significance. Knowledge of the origin of these diseases has been accumulated over decades from the multitude of intrinsic and extrinsic triggering factors based on biomechanical considerations with an evidence-based medicine (EBM) level 5. A high correlation between tendinopathy and hypervascularization of the Achilles tendon was found in a double-blind randomized prospective study using Doppler ultrasound (EBM level 1) but these results were not reproducible; therefore, the importance of these findings is unclear. Inspection and clinical examination supplemented by ultrasound and magnetic resonance imaging (MRI) are essential to achieve the correct diagnosis. The varying extent of load-dependent irritation of tendons and the surrounding tissues and the individual variation in experience of investigators mean that the results of clinical examinations are difficult to collate or not reproducible and cannot be investigated in studies. The expression of the varying results is difficult to assess even by the use of sonography and magnetic resonance imaging (MRI). Conservative treatment of tendinopathy is based on medical experience (EBM level 5). The effectiveness of physiotherapeutic eccentric loading and extracorporal shock wave treatment (ESWT) for Achilles tendinopathy was demonstrated in several case control studies and series (EBM level 3). Due to the high rate of healing with physiotherapy, surgery should only be performed following a minimum of 6-12 weeks of unsuccessful conservative treatment, because formation of scar tissue on the foot can result in permanent complaints (EBM level 4).

Is Sonographic Assessment of Intratendinous Blood Flow in Achilles Tendinopathy Patients Reliable?: Consistency of Doppler Ultrasound Modes and Intra- and Inter-observer Reliability

PURPOSE

The purpose of this study was to investigate the consistency between different Doppler ultrasound (DU) modes as well as the intra- and inter-observer reliability of investigators with different experience level in assessing intratendinous blood flow (IBF) in Achilles tendinopathy patients.

MATERIAL AND METHODS

18 participants (36 Achilles tendons, AT) with Achilles tendinopathy (24 AT) were examined with power Doppler ultrasound (PDU), colour Doppler ultrasound (CDU) and "Advanced Dynamic Flow" (ADF) (Toshiba Xario SSA-660 A; 14MHz transducer) by 2 investigators (experienced, EI; inexperienced, II) in a test-retest design (M1/M2). A modified Öhberg score was used to quantify IBF. Data was analysed descriptively (absolute and relative). Consistency of the 3 modes was presented by Kendall's Coefficient of Concordance (Kendall's W). Intra- and inter-observer reliability were calculated by use of Kendall's tau b correlation coefficient.

RESULTS

IBF was detected in 79-92% of symptomatic AT and in 33-50% of contralateral asymptomatic AT. Comparing the 3 modes, Kendall's W ranged from 0.97-0.98. Analysis of intra-observer reliability resulted in Kendall's tau 0.90-0.92 for EI and 0.84-0.87 for II. Inter-observer reliability resulted in Kendall's tau 0.64-0.69 in M1 and 0.68-0.70 in M2.

CONCLUSION

The very good consistency between PDU, CDU and ADF indicates a comparable applicability for assessing IBF in ATs. Intra-observer reliability was high for both investigators, independent of experience. The moderate inter-observer reliability reflects the challenge in sonographic detection of intratendinous blood flow (IBF) amount.

Not All Tendons Are Created Equal: Implications for Differing Treatment Approaches

The majority of muscles have distinct tendinous attachments to bones; however, only a few tendons develop painful conditions. That simple observation prompts us to ask a few questions. Are there commonalities in morphology and pathology among the painful tendons? What contributes to the propensity for pathology in some, but not all, tendons? And, consequently, should all tendinopathies be managed equally? Two common tendinopathies are those affecting the Achilles and supraspinatus, which are presented in this special issue and serve as excellent models to discuss similarities and contrasts. J Orthop Sports Phys Ther 2015;45(11):829-832. doi:10.2519/jospt.2015.0114.

Pharmacological interventions for the treatment of Achilles tendinopathy: a systematic review of randomized controlled trials

INTRODUCTION

Several pharmacological interventions have been proposed for the management of Achilles tendinopathy, with no agreement on which is the overall best option available. This systematic review investigates the efficacy and safety of different local pharmacological treatments for Achilles tendinopathy.

SOURCES OF DATA

We included only randomized controlled studies (RCTs) focusing on clinical and functional outcomes of therapies consisting in injection of a substance or local application. Assessment of the methodological quality was performed using a modified version of the Coleman methodology score (CMS) to determine possible risks of bias.

AREAS OF AGREEMENT

Thirteen RCTs were included with a total of 528 studied patients. Eleven studies reported the outcomes of injection therapies. Two studies examined the outcomes of patients who applied glyceryl trinitrate patch. The mean modified CMS was 70.6 out of 90.

AREAS OF CONTROVERSY

There was no significant evidence of remarkable benefits provided by any of the therapies studied.

GROWING POINTS

There is not univocal evidence to advise any particular pharmacological treatment as the best advisable non-operative option for Achilles tendinopathy as equivalent alternative to the most commonly used eccentric loading rehabilitation program. However, potential was shown by the combination of different substances administered with physical therapy.

RESEARCH

There is a need for more long-term investigations, studying large enough cohort with standardized scores and evaluations shared by all the investigations to confirm the healing potential, and provide a stronger statistical comparison of the available treatments.

Obesity as a risk factor for tendinopathy: a systematic review

Purpose. In the last few years, evidence has emerged to support the possible association between increased BMI and susceptibility to some musculoskeletal diseases. We systematically review the literature to clarify whether obesity is a risk factor for the onset of tendinopathy. Methods. We searched PubMed, Cochrane Central, and Embase Biomedical databases using the keywords "obesity," "overweight," and "body mass index" linked in different combinations with the terms "tendinopathy," "tendinitis," "tendinosis," "rotator cuff," "epicondylitis," "wrist," "patellar," "quadriceps," "Achilles," "Plantar Fascia," and "tendon." Results. Fifteen studies were included. No level I study on this subject was available, and the results provided are ambiguous. However, all the 5 level II studies report the association between obesity measured in terms of BMI and tendon conditions, with OR ranging between 1.9 (95% CI: 1.1-2.2) and 5.6 (1.9-16.6). Conclusions. The best evidence available to date indicates that obesity is a risk factor for tendinopathy. Nevertheless, further studies should be performed to establish the real strength of the association for each type of tendinopathy, especially because the design of the published studies does not allow identifying a precise cause-effect relationship and the specific role of obesity independently of other metabolic conditions.

Continuum model of tendon pathology - where are we now?

Chronic tendon pathology is a common and often disabling condition, the causes of which remain poorly understood. The continuum model of tendon pathology was proposed to provide a model for the staging of tendon pathology and to assist clinicians in managing this often complex condition (Br. J. Sports Med., 43, 2009, 409). The model presents clinical, histological and imaging evidence for the progression of tendon pathology as a three-stage continuum: reactive tendinopathy, tendon disrepair and degenerative tendinopathy. It also provides clinical information to assist in identifying the stage of pathology, in addition to proposed treatment approaches for each stage. The usefulness of such a model is determined by its ability to incorporate and inform new and emerging research. This review examines the degree to which recent research supports or refutes the continuum model and proposes future directions for clinical and research application of the model.

Platelet-rich plasma for the treatment of patellar tendinopathy: clinical and imaging findings at medium-term follow-up

PURPOSE

The purpose of this study was to evaluate the efficacy of multiple platelet-rich plasma (PRP) injections on the healing of chronic refractory patellar tendinopathy, and report the quality and duration of the clinical improvement up to a medium-term follow-up.

METHODS

Forty-three patients (mean age, 30.6 years; mean BMI, 24.7; 42 men, one woman) affected by chronic patellar proximal tendinopathy were enrolled in this trial. Eleven patients were affected by bilateral tendinopathy. They underwent three ultrasound guided intra-tendinous injections of five millilitres PRP, two weeks apart from each other. Patients were prospectively evaluated initially, then after two, six, and up to mean 48.6 ± 8.1 months of follow-up (minimum evaluation at 36 months). The following evaluation tools were used: Blanzina, VISA-P, EQ-VAS for general health, and Tegner scores. Patients' overall satisfaction and time to return to sport were also reported.

RESULTS

Good and stable results were documented over time, with the VISA-P score increasing from 44.1 ± 15.6 at baseline to 61.4 ± 22.2 at two months, 76.6 ± 25.4 at six months, and 84.3 ± 21.6 at four years' follow-up. The same trend was confirmed by the other scores used, and 80 % of the patients were satisfied and returned to previous sports activities. Significantly poorer results were obtained in patients with a longer history of symptoms, and poor results were also observed in bilateral lesions. No correlation between ultrasonographic and clinical findings could be found.

CONCLUSIONS

Multiple injections of PRP provided a good clinical outcome for the treatment of chronic recalcitrant patellar tendinopathy with stable results up to medium-term follow-up. Patients affected by bilateral pathology and presenting a long history of pain obtained significantly poorer results.

Achilles tendon: functional anatomy and novel emerging models of imaging classification

PURPOSE

Ideally, a classification should have some prognostic value, and should therefore include precise information upon extent and location of the Achilles tendon disorders. We propose a new imaging and anatomical system to classify Achilles tendon disorders at imaging using US and MRI.

APPROACH

We consider the non-insertional region as the tendon mid-portion, and distinguish the insertional component into a pre-insertion site, located about two centimetres above the calcaneum, and a calcaneal insertion, where the tendon is attached to the bone. On sagittal scans, we introduced a new classification which considers two main portions: "musculotendinous" and "insertional". In the context of the muscolotendinous portion, it is possible to find muscle fibres proximally, and the free tendon distally. This latter is made up of proximal, middle and distal portions. We also propose a 5 grade Doppler classification system to quantify blood flow, in which Grades I and II are respectively characterised by the presence of one and two vessels within the tendon; in Grades III, IV and V, the neovascularisation respectively involves less than 50 %, from 50 to 90 %, and more than 90 % of the tendon tissue. These proposed systems will require validation and possible modification to be applied to different tendons.