Achilles Tendinopathy

The Efficacy of Intratissue Percutaneous Electrolysis (EPI®) and Nutritional Factors for the Treatment of Induced Tendinopathy in Wistar Rats: Hepatic Intermediary Metabolism Effects

Achilles tendinopathy (TP) is characterized as the third most common disease of the musculoskeletal system, and occurs in three phases. There is currently no evidence of effective treatment for this medical condition. In this study, the modulatory effects of the minimally invasive technique intratissue percutaneous electrolysis (EPI) and combinations of EPI with four nutritional factors included in the diet, hydroxytyrosol (HT), maslinic acid (MA), glycine, and aspartate (AA), on hepatic intermediary metabolism was examined in Wistar rats with induced tendinopathy at various stages of TP. Results obtained showed that induced tendinopathy produced alterations in the liver intermediary metabolisms of the rats. Regarding carbohydrate metabolism, a reduction in the activity of pro-inflammatory enzymes in the later stages of TP was observed following treatment with EPI alone. Among the combined treatments using nutritional factors with EPI, HT+EPI and AA+EPI had the greatest effect on reducing inflammation in the late stages of TP. In terms of lipid metabolism, the HT+EPI and AA+EPI groups showed a decrease in lipogenesis. In protein metabolism, the HT+EPI group more effectively reduced the inflammatory effects of induced TP. Treatment with EPI combined with nutritional factors might help regulate intermediary metabolism in TP disease and reduce the inflammation process.

Cross-Cultural Adaptation, Translation, and Validation of the Victorian Institute of Sport Assessment-Achilles Questionnaire (VISA-A) for Use With Arabic-Speaking Patients With Achilles Tendinopathy

Background

The Victorian Institute of Sport Assessment-Achilles (VISA-A) questionnaire is a validated instrument for assessing symptoms of Achilles tendinopathy (AT). However, there is a need to validate the Arabic version of the VISA-A (VISA-A-AR) in Arabic-speaking patients with AT.

Purpose

To validate the VISA-A-AR in Arabic patients with AT and evaluate its reliability and validity.

Study Design

Cohort study (diagnosis); Level of evidence, 3.

Methods

The translation and cultural adaptation of the VISA-A questionnaire into Arabic followed international guidelines. A total of 81 participants were recruited, including 45 patients diagnosed with AT and 36 healthy individuals. The AT group comprised male and female native Arabic speakers aged ≥18 years who were diagnosed with and had symptoms of AT. The inclusion criteria for the healthy group were the same, except that they must not have had AT at the time of the study or previously. The exclusion criteria were individuals with a partial or complete Achilles tendon rupture or prior Achilles tendon surgery. The internal consistency of the VISA-A-AR was assessed using the Cronbach α coefficient. Test-retest reliability was evaluated using the intraclass correlation coefficient (ICC[3,1]). Construct validity was assessed through correlation analysis between VISA-A-AR scores and the Arabic versions of the Short Form-36 Health Survey (SF-36-AR) and the Numeric Pain Rating Scale (ANPRS). Differences in VISA-A-AR scores between patients with AT and healthy controls were analyzed using appropriate statistical tests.

Results

The VISA-A-AR demonstrated a high level of internal consistency (Cronbach α = 0.935) and excellent test-retest reliability (ICC[3,1] = 0.985). Significant positive correlations were observed between VISA-A-AR scores and SF-36-AR (r(43) = 0.838, P < .001), indicating good construct validity. In addition, VISA-A-AR scores showed a significant negative correlation with ANPRS (rS(43) = -0.835, P < .001). Furthermore, VISA-A-AR scores exhibited a significant difference between patients with AT (mean, 45.82 ± 16.65) and healthy controls (mean, 99.94 ± 0.33) (P < .001).

Conclusion

The findings of this study validate the VISA-A-AR as a reliable and valid tool for assessing symptoms of AT in Arabic-speaking patients.

Flexor hallucis longus tendon morphology in dancers clinically diagnosed with tendinopathy

PURPOSE

The unique demands of dance technique make dancers more prone to certain pathologies especially of the foot and ankle. Flexor hallucis longus (FHL) tendinopathy, colloquially known as "dancer's tendinopathy," is common in dancers and not well studied. The purpose of this study was to assess if morphological alterations in tendon structure occur as an adaptive response to dance activity by comparing the FHL tendon in dancers to non-dancers, and if pathology further alters tendon morphology in dancers clinically diagnosed with tendinopathy.

METHODS

Three groups of ten participants were recruited (healthy non-dancers, healthy dancers, and dancers with FHL tendinopathy). Ultrasound images of the FHL tendons were analyzed for macromorphology by measuring the tendon thickness. The micromorphology was analyzed by determining the peak spatial frequency radius of the tendon. Our study did find increased tendon proper and composite tendon thickness in dancers with tendinopathy but no difference between asymptomatic dancers and non-dancers.

RESULTS

There was no significant difference in micromorphology found between any of the groups. As expected, dancers with tendinopathy demonstrated increased composite tendon and tendon proper thickness however, there was no evidence of adaptive thickening of the FHL tendon as might be expected for the dance population. There was also no evidence of micromorphological changes in the presence of clinically diagnosed FHL tendinopathy.

CONCLUSION

Because of the limited normative data for this pathology, these results can help improve diagnosis and therefore treatment for dancers to decrease the impact of this injury on their careers.

Per-step and cumulative load at three common running injury locations: The effect of speed, surface gradient, and cadence

Understanding how loading and damage on common running injury locations changes across speeds, surface gradients, and step frequencies may inform training programs and help guide progression/rehabilitation after injuries. However, research investigating tissue loading and damage in running is limited and fragmented across different studies, thereby impairing comparison between conditions and injury locations. This study examined per-step peak load and impulse, cumulative impulse, and cumulative weighted impulse (hereafter referred to as cumulative damage) on three common injury locations (patellofemoral joint, tibia, and Achilles tendon) across different speeds, surface gradients, and cadences. We also explored how cumulative damage in the different tissues changed across conditions relative to each other. Nineteen runners ran at five speeds (2.78, 3.0, 3.33, 4.0, 5.0 m s-1 ), and four gradients (-6, -3, +3, +6°), and three cadences (preferred, ±10 steps min-1 ) each at one speed. Patellofemoral, tibial, and Achilles tendon loading and damage were estimated from kinematic and kinetic data and compared between conditions using a linear mixed model. Increases in running speed increased patellofemoral cumulative damage, with nonsignificant increases for the tibia and Achilles tendon. Increases in cadence reduced damage to all tissues. Uphill running increased tibial and Achilles tendon, but decreased patellofemoral damage, while downhill running showed the reverse pattern. Per-step and cumulative loading, and cumulative loading and cumulative damage indices diverged across conditions. Moreover, changes in running speed, surface gradient, and step frequency lead to disproportional changes in relative cumulative damage on different structures. Methodological and practical implications for researchers and practitioners are discussed.

Common Painful Foot and Ankle Conditions: A Review

Importance

Morton neuroma, plantar fasciitis, and Achilles tendinopathy are foot and ankle conditions that are associated with pain and disability, but they can respond to nonoperative treatment.

Observations

Morton neuroma, consisting of interdigital neuronal thickening and fibrosis, is characterized by burning pain in the ball of the foot and numbness or burning pain that may radiate to the affected toes (commonly the third and fourth toes). First-line nonoperative therapy consists of reducing activities that cause pain, orthotics, and interdigital corticosteroid injection; however, approximately 30% of patients may not respond to conservative treatment. Plantar fasciitis accounts for more than 1 million patient visits per year in the US and typically presents with plantar heel pain. Fifteen years after diagnosis, approximately 44% of patients continue to have pain. First-line nonoperative therapy includes stretching of the plantar fascia and foot orthotics, followed by extracorporeal shockwave therapy, corticosteroid injection, or platelet-rich plasma injection. Midportion Achilles tendinopathy presents with pain approximately 2 to 6 cm proximal to the Achilles insertion on the heel. The primary nonoperative treatment involves eccentric strengthening exercises, but extracorporeal shockwave therapy may be used.

Conclusions and Relevance

Morton neuroma, plantar fasciitis, and Achilles tendinopathy are painful foot and ankle conditions. First-line therapies are activity restriction, orthotics, and corticosteroid injection for Morton neuroma; stretching and foot orthotics for plantar fasciitis; and eccentric strengthening exercises for Achilles tendinopathy.

Different clinical presentations of Achilles tendinopathy: a cross-sectional study

Achilles tendinopathy (AT) is a common debilitating tendon disorder in the lower extremity. Clinical presentation of AT might differ from place to place, depending on different variables including cultural factors. This study was conducted to determine the clinical picture of AT in a group of clients referring to an outpatient orthopedics clinic in Shiraz, southern Iran. In this cross-sectional study, a convenient sample of 61 (46 female and 15 male) patients attending to a referral outpatient clinic affiliated to Shiraz University of Medical Sciences with a definite diagnosis of AT was studied. Patients with partial- or full-thickness tear of Achilles tendon, history of radicular pain or lower extremity injury, previous history of surgery on their lower extremity, and pregnant women were excluded from the study. We used Maffulli et al. (Foot Ankle Surg 26:240-9, 2020) criteria for the diagnosis of AT in our patients. The patients had a mean age of 47.7 (SD 11.1) years and mean BMI of 28.7 (4.2) kg/m2. There was no significant correlation between the age and body mass index of the participants (Pearson's r = -0.028, p = 0.832). The prevalence of insertional AT among 58 patients with only one site affected, was 84% (95% CI 72-92%), significantly (p < 0.001) higher than that of midportional AT (16%). Women were more frequently affected than men (p < 0.001). The clinical presentation of AT in southern Iran is somewhat different from those reported in other parts of the world. Further studies on larger groups of patients should be done to determine the causes of the observed differences.

Percutaneous cruciate repair of ruptured Achilles tendon

Percutaneous repair is a safe and reliable method to restore continuity after acute Achilles tendon ruptures, with a lower incidence of wound complications compared to open techniques. We describe a novel percutaneous cruciate suture performed through 5 stab skin incisions, four of which are longitudinal and parallel to the course of the sural nerve to minimize the risk of injury and one transverse incision at the site of rupture, with a total of 16 suture threads and the knot outside the tendon body, increasing the tensile strength of the suture and minimizing the risk of re-rupture. Clinical studies are necessary to ascertain whether the theoretical advantages of the cruciate suture technique translate into better clinical outcomes compared to established percutaneous techniques.

Low-volume Hydrodissection for the Treatment of Chronic Achilles Tendinopathy

Chronic Achilles tendinopathy (AT) is a common ailment for many active duty service members that adversely affects readiness. Patients present with pain, swelling, and limited functional ability. Kager's fat pad is a mass of adipose tissue that protects the blood vessels supplying the Achilles tendon and preserves its function. A popular hypothesis is that scarring, tethering, and neovascularization play a significant role in the pathogenesis of AT. Current literature supports the effectiveness of high-volume (40-50 mL) hydrodissection, a procedure in which fluid is injected under ultrasound guidance into the tissues surrounding the Achilles tendon to mechanically separate the paratenon from the underlying Kager's fat pad. There may also be a beneficial effect of scar tissue and neoneurovascular breakdown. However, high-volume injections result in short-term discomfort and decreased mobility. Lowering injection volume (2-10 mL) may reduce this morbidity and facilitate use in limited-resource environments. This case report presents a 29-year-old active duty male with recalcitrant post-traumatic AT who achieved significant pain reduction and faster return to full service using low-volume hydrodissection. The use of 10 mL volume has not been described previously and provides additional support for using lower volumes in chronic AT. This technique is a direct adjunctive treatment option with rehabilitation at a military treatment facility or in the operational environment.

Calcification alters the viscoelastic properties of tendon fascicle bundles depending on matrix content

Tendon fascicle bundles are often used as biological grafts and thus must meet certain quality requirements, such as excluding calcification, which alters the biomechanical properties of soft tissues. In this work, we investigate the influence of early-stage calcification on the mechanical and structural properties of tendon fascicle bundles with varying matrix content. The calcification process was modeled using sample incubation in concentrated simulated body fluid. Mechanical and structural properties were investigated using uniaxial tests with relaxation periods, dynamic mechanical analysis, as well as magnetic resonance imaging and atomic force microscopy. Mechanical tests showed that the initial phase of calcification causes an increase in the elasticity, storage, and loss modulus, as well as a drop in the normalized value of hysteresis. Further calcification of the samples results in decreased modulus of elasticity and a slight increase in the normalized value of hysteresis. Analysis via MRI and scanning electron microscopy showed that incubation alters fibrillar relationships within the tendon structure and the flow of body fluids. In the initial stage of calcification, calcium phosphate crystals are barely visible; however, extending the incubation time for the next 14 days results in the appearance of calcium phosphate crystals within the tendon structure and leads to damage in its structure. Our results show that the calcification process modifies the collagen-matrix relationships and leads to a change in their mechanical properties. These findings will help to understand the pathogenesis of clinical conditions caused by calcification process, leading to the development of effective treatments for these conditions. STATEMENT OF SIGNIFICANCE: This study investigates how calcium mineral deposition in tendons affects their mechanical response and which processes are responsible for this phenomenon. By analyzing the elastic and viscoelastic properties of animal fascicle bundles affected by calcification induced via incubation in concentrated simulated body fluid, the study sheds light on the relationship between structural and biochemical changes in tendons and their altered mechanical response. This understanding is crucial for optimizing tendinopathy treatment and preventing tendon injury. The findings provide insights into the calcification pathway and its resulting changes in the biomechanical behaviors of affected tendons, which have been previously unclear.

Programmable DNA Hydrogel Provides Suitable Microenvironment for Enhancing TSPCS Therapy in Healing of Tendinopathy

Tendon stem/progenitor cells (TSPCs) therapy is a promising strategy for enhancing cell matrix and collagen synthesis, and regulating the metabolism of the tendon microenvironment during tendon injury repair. Nevertheless, the barren microenvironment and gliding shear of tendon cause insufficient nutrition supply, damage, and aggregation of injected TSPCs around tendon tissues, which severely hinders their clinical application in tendinopathy. In this study, a TSPCs delivery system is developed by encapsulating TSPCs within a DNA hydrogel (TSPCs-Gel) as the DNA hydrogel offers an excellent artificial extracellular matrix (ECM) microenvironment by providing nutrition for proliferation and protection against shear forces. This delivery method restricts TSPCs to the tendons, significantly extending their retention time. It is also found that TSPCs-Gel injections can promote the healing of rat tendinopathy in vivo, where cross-sectional area and load to failure of injured tendons in rats are significantly improved compared to the free TSPCs treatment group at 8 weeks. Furthermore, the potential healing mechanism of TSPCs-Gel is investigated by RNA-sequencing to identify a series of potential gene and signaling pathway targets for further clinical treatment strategies. These findings suggest the potential pathways of using DNA hydrogels as artificial ECMs to promote cell proliferation and protect TSPCs in TSPC therapy.

Computational Analysis of miR-140 and miR-135 as Potential Targets to Develop Combinatorial Therapeutics for Degenerative Tendinopathy

Background

Degenerative tendinopathy, a condition causing movement restriction due to high pain, highly impacts productivity and quality of life. The healing process is a complex phenomenon and involves a series of intra-cellular and inter-cellular processes. Proliferation and differentiation of the tenocyte is a major and essential process to heal degenerative tendinopathy. The recent development in microRNA (miRNA)-mediated reprogramming of the cellular function through specific pathways opened door for the development of new regenerative therapeutics. Based on information about gene expression and regulation of tendon injury and healing, we attempted to evaluate the combinatorial effect of selected miRNAs for better healing of degenerative tendinopathy.

Methods

The present study was designed to evaluate the combinatorial effect of two miRNAs (has-miR-140 and has-miR-135) in the healing process of the tendon. Publicly available information/data were retrieved from appropriate platforms such as PubMed. Only molecular data, directly associated with tendinopathies, including genes/proteins and miRNAs, were used in this study. The miRNAs involved in tendinopathy were analyzed by a Bioinformatics tools (e.g., TargetScan, miRDB, and the RNA22v2). Interactive involvement of the miRNAs with key proteins involved in tendinopathy was predicted by the Insilco approach.

Results

Based on information available in the public domain, tendon healing-associated miRNAs were predicted to explore their therapeutic potentials. Based on computation analysis, focusing on the potential regulatory effect on tendon healing, the miR-135 and miR-140 were selected for this study. These miRNAs were found as key players in tendon healing through Rho-associated coiled-coil containing protein kinase 1 (ROCK1), IGF-1/PI3K/Akt, PIN, and Wnt signaling pathways. It was also predicted that these miRNAs may reprogram the cells to induce proliferation and differentiation activity. Many miRNAs are likely to regulate genes important for the tendinopathy healing process, and the result of this study allows an approach for miRNA-mediated regeneration of the tenocyte for tendon healing. Based on computational analysis, the role of these miRNAs in different pathways was established, and the results provided insights into the combinatorial approach of miRNA-mediated cell reprogramming.

Conclusions

In this study, the association between miRNAs and the disease was evaluated to correlate the tendinopathy genes and the relevant role of different miRNAs in their regulation. Through this study, it was established that the synergistic effect of more than one miRNA on directed reprogramming of the cell could be helpful in the regeneration of damaged tissue. It is anticipated that this study will be helpful for the design of miRNA cocktails for the orchestration of cellular reprogramming events.

Pro-inflammatory activity of long noncoding RNA FOXD2-AS1 in Achilles tendinopathy

Achilles tendinopathy is a prevalent clinical problem that plagues athletes and general populations. Achilles tendon healing is a complex process, and so far, there is no successful long-term solution to Achilles tendinopathy in the field of microsurgery due to its poor natural regeneration ability. Limitations in understanding the pathogenesis of Achilles tendon development and Achilles tendon injury hinder clinical treatment developments. There is an increasing demand for innovative conservative treatments that can improve Achilles tendon injury. In this study, a Sprague-Dawley rat model of Achilles tendinopathy was established. Lentiviral vectors that interfere with the expression of FOXD2-AS1, miR-21-3p, or PTEN were injected every 3 days. Rats were euthanized after 3 weeks, and the effect of FOXD2-AS1, miR-21-3p, or PTEN on Achilles tendon healing was analyzed by histological observation, biomechanical test, and examinations of inflammatory factors and tendon markers. As measured, downregulating FOXD2-AS1 or upregulating miR-21-3p improved histological structure, suppressed inflammation, promoted the expression of tendon markers, and optimized the biomechanical properties of Achilles tendon. Upregulating PTEN was capable of reversing the promoting effect of inhibition of FOXD2-AS1 on Achilles tendon healing. As concluded, deficiency of FOXD2-AS1 accelerates the healing of Achilles tendon injury and improves tendon degeneration by regulating the miR-21-3p/PTEN axis and promoting the activation of the PI3K/AKT signaling pathway.

The load borne by the Achilles tendon during exercise: A systematic review of normative values

The Achilles tendon (AT) can be exposed to considerable stress during athletic activities and is often subject to pathologies such as tendinopathies. When designing a prevention or rehabilitation protocol, mechanical loading is a key factor to consider. This implies being able to accurately determine the load applied to the AT when performing exercises that stress this tendon. A systematic review was performed to synthesize the load borne by the AT during exercises/activities. Three databases (Pubmed, Embase and Cochrane) were searched for articles up to May 2021, and only the studies assessing the AT load in newtons relative to body-weight (BW) on humans during activities or exercises were included. Most of the 11 included studies assessed AT load when running or walking (N = 10), and only three tested exercises were usually performed during rehabilitation. The load on the tendon ranged from 2.7 to 3.95 BW when walking, from 4.15 to 7.71 BW when running, and from 0.41 to 7.3 BW according to the strengthening exercise performed. From the collected data, a progression of exercises progressively loading the Achilles tendon, as well as the possible connections with walking and running activities, could be defined. However, the trends highlighted in the relationship between tendon loading and walking or running speeds present some inconsistencies. Further research is still needed to clarify them, but also to complete the data set in healthy and injured people.

Immortalized murine tenocyte cells: a novel and innovative tool for tendon research

Primary tenocytes rapidly undergo senescence and a phenotypic drift upon in vitro monolayer culture, which limits tendon research. The Ink4a/Arf locus encodes the proteins p16^Ink4a/Arf and p14^ARF (p19^ARF in mice) that regulate cell cycle progression and senescence. We here established an immortalized cell line using tenocytes isolated from Ink4a/Arf deficient mice (Ink4a/Arf^-/-). These cells were investigated at three distinct time points, at low (2-5), intermediate (14-17) and high (35-44) passages. Wild-type cells at low passage (2-5) served as controls. Ink4a/Arf^-/- tenocytes at all stages were comparable to wild-type cells regarding morphology, expression of tenogeneic genes (collagen type 1, 3 and 5, Scleraxis, Tenomodulin and Tenascin-C), and surface markers (CD29, CD44 and CD105) and form 3D tendon-like structures. Importantly, Ink4a/Arf^-/- tenocytes maintained their phenotypic features and proliferation potential in culture for more than 40 passages and also following freeze-thaw cycles. In contrast, wild-type tenocytes underwent senescence starting in passage 6. These data define Ink4a/Arf^-/- tenocytes as novel tool for in vitro tendon research and as valuable in vitro alternative to animal experiments.

Eccentric exercise is more effective than other exercises in the treatment of mid-portion Achilles tendinopathy: systematic review and meta-analysis

Achilles tendinopathy (AT) is one of the most frequent overuse injuries in the ankle. The evidence base for its conservative management AT continues to evolve, but there is still a gap in the evidence for the efficacy of any modality of treatment in high-quality studies. This systematic review and meta-analysis investigated the efficacy of EE in improving pain and function in adult patients with mid-portion Achilles tendinopathy compared to other forms of exercise. A search was performed in PubMed, BIREME, SportDiscus, Cinahl, Web of Science and PEDro, in November 2022. The methodological quality was evaluated using the Risk of Bias 2 tool (RoB2) of the Cochrane collaboration, and the meta-analysis was performed using the Review Manager 5.1 program. 2024 articles were identified and eight fulfilled the inclusion criteria. RoB2 presented a final score with 62.5% of the studies presented "some concerns", and 37.5% (five and three articles, respectively) presenting "high risk" of bias. EE was effective for the managment of AT. The only variable for which a meta-analysis was possible was pain (five articles), analysed with the visual analogue scale/numerical visual scale. The mean difference (MD) in treatment effect using EE was - 1.21 (- 2.72 to - 0.30) with a 95% of confidence interval (CI), thus identifying a significant positive effect for the improvement of pain in patients with AT in whom EE was used. EE is effective in the management of AT. The meta-analysis shows the need for appropriately powered randomized controlled trials with better design, the use of standard outcome measures and well-planned protocols for conservative management of AT.Level of evidence: Level 1.Registration: CRD42018118016.

Psychosocial and individual factors affecting Quality of Life (QoL) in patients suffering from Achilles tendinopathy: a systematic review

BACKGROUND

Achilles tendinopathy (AT) is a joint condition that causes functional restrictions and pain. This condition negatively impacts patients' social connectedness and psychological well-being, reducing their quality of life (QoL). This review aims to summarise the current information on QoL in patients suffering from AT from different angles: compared to a healthy population, reported individual factors that influence it and the effects of some AT interventions on QoL.

METHODS

A systematic review was conducted at PubMed, Cochrane, Google Scholar, and PsycINFO using tendinopathy and QoL-related keywords up to November 2021. Articles were included if they compared QoL to demographic factors such as age or gender, lifestyle factors (physical activity levels), comorbidity factors (diabetes, obesity), and/or a control group.

RESULTS

Three hundred twenty-nine articles were reviewed; 23 met the inclusion criteria. SF-36, EQ-5D, and VISA-A were the most common instrument used. Patients with AT reported low QoL when compared to no AT population. When women were compared to men, women reported worse QoL. The patients who participated in different exercise programs (strengthening and stretching) showed improvements in QoL. Surgical AT intervention improved QoL, although results varied by age.

CONCLUSION

AT has a substantial impact on QoL. In AT patients, QoL is also influenced by specific individual factors, including gender and physical activity. Exercise, education, and surgical treatment improve QoL. We suggest more research on AT patients to better understand the aspects leading to poor QoL.

The Victorian Sports Assessment Institute-Achilles Tendinopathy Questionnaire (VISA-A): Chinese cross-cultural adaptation and psychometric validation

Purpose

We aimed to create a standardized cross-cultural adaptation of the simplified Chinese version of VISA-A, test its reliability and validity and conduct exploratory factor analysis on the correlation between items.

Methods

According to international recommendations for the cross-cultural adaptation of questionnaires, after considering the opinions of patients, we translated and revised the English version to create a simplified Chinese version of the questionnaire. We recruited healthy subjects in the general specialty of one university (n = 90) and the physical education specialty of another university (n = 89), and we recruited patients with Achilles tendinopathy in a third group (n = 85). Reliability was evaluated by calculating test–retest reliability and internal consistency, validity was evaluated by exploring structural and criterion validity (correlation with the physical function and body pain items of the SF-36), and responsiveness was evaluated by calculating area under the receiver operating characteristic curve (AUC).

Results

The simplified Chinese version of the VISA-A had no ceiling or floor effects. Four common factors were extracted and explained by the exploratory factor analysis. The test–retest reliability (ICC = 0.97) and internal consistency (Cronbach’s alpha = 0.84) were adequate. The questionnaire had moderate correlations with the physical function and body pain items of the SF-36. The AUC was 0.9407.

Conclusion

The simplified Chinese version of the VISA-A had good reliability and validity and excellent responsiveness, but the factorial structure is not inconsistent with the dimensions of the original version. It can be used to assess and manage patients with Achilles tendinitis in the Chinese culture.

Large animal models for the study of tendinopathy

Tendinopathy has a high incidence in athletes and the aging population. It can cause pain and movement disorders, and is one of the most difficult problems in orthopedics. Animal models of tendinopathy provide potentially efficient and effective means to develop understanding of human tendinopathy and its underlying pathological mechanisms and treatments. The selection of preclinical models is essential to ensure the successful translation of effective and innovative treatments into clinical practice. Large animals can be used in both micro- and macro-level research owing to their similarity to humans in size, structure, and function. This article reviews the application of large animal models in tendinopathy regarding injuries to four tendons: rotator cuff, patellar ligament, Achilles tendon, and flexor tendon. The advantages and disadvantages of studying tendinopathy with large animal models are summarized. It is hoped that, with further development of animal models of tendinopathy, new strategies for the prevention and treatment of tendinopathy in humans will be developed.

Research protocol to evaluate the effectiveness of shockwave therapy, photobiomodulation and physical therapy in the management of non-insertional Achilles tendinopathy in runners: a randomised control trial with elective cross-over design

Background

Achilles tendinopathy (AT) is a common overuse injury in runners. While the mainstay of treatment for AT is tendon loading exercises (physical therapy and exercise programme (EXER)), some patients have refractory symptoms. Extracorporeal shockwave therapy (ESWT) and photobiomodulation therapy (PBMT) have each been evaluated to facilitate tendon healing; the influence of combining treatments is unknown and limited studies have been completed in runners. This randomised control study, with an elective cross-over at 3 months, will evaluate the efficacy of three forms of treatment of non-insertional AT: (1) EXER (loading programme specific to Achilles tendon combined with physical therapy); (2) EXER and ESWT; (3) EXER, ESWT and PBMT. Sixty runners will be assigned using block randomisation into one of three treatment groups (n=20). After 3 months, each participant may elect a different treatment than previously assigned and will be followed for an additional 3 months. The EXER Achilles loading programme will be standardised using the Silbernagel at-home programme. The primary outcome of interest is treatment group responses using the Victorian Institute of Sports Assessment—Achilles (VISA-A) Score. Secondary outcomes include the Patient-Reported Outcomes Measurement Information System—29 questions, the University of Wisconsin Running Injury and Recovery Index, heel raise to fatigue test, hopping test and ultrasound measurements. We will also capture patient preference and satisfaction with treatment. We hypothesise that the cohorts assigned EXER+ESWT+PBMT and EXER+ESWT will see greater improvements in VISA-A than the EXER cohort, and the largest gains are anticipated in combining ESWT+PBMT. The elective cross-over phase will be an exploratory study and will inform us whether patient preference for treatment will impact the treatment response.

Trial registration number

NCT04725513.

Therapeutic Ultrasound and Shockwave Therapy for Tendinopathy: A Narrative Review

ABSTRACT

Tendon injury is prevalent and costly in the United States, comprising 45% of the 66 million musculoskeletal injuries and costing $114 billion annually. Surgical and therapeutic methods, such as arthroscopic surgery, dry needling, and physical therapy, produce mixed success in reintroducing a healing response in tendinopathy due in part to inconsistent dosing and monitoring. Ultrasound is one therapeutic modality that has been shown to noninvasively induce bioeffects in tendon that may help promote healing. However, results from this modality have also been mixed. This review compares the current state of the field in therapeutic ultrasound and shockwave therapy, including low-intensity therapeutic ultrasound, extracorporeal shockwave therapy, and radial shockwave therapy, and evaluates the efficacy in treating tendinopathies with ultrasound. We found that the mixed successes may be attributed to the wide variety of achievable parameters within each broader treatment type and the lack of standardization in measurements and reporting. Despite mixed outcomes, all three therapies show potential as an alternative therapy with lower-risk adverse effects than more invasive methods like surgery. There is currently insufficient evidence to conclude which ultrasound modality or settings are most effective. More research is needed to understand the healing effects of these different therapeutic ultrasound and shockwave modalities.

A novel technique of minimally invasive calcaneal osteotomy for intractable insertional Achilles tendinopathy associated with Haglund deformity

BACKGROUND

To date, minimally invasive surgery (MIS) involving calcaneal osteotomy for Haglund deformity associated with intractable insertional Achilles tendinopathy has not been reported. This study presents the radiographic and clinical outcomes of our novel MIS-dorsal closing wedge calcaneal osteotomy (DCWCO) technique compared to open Haglund resection. We hypothesized that earlier clinical improvement after MIS-DCWCO could be achieved by leaving the Achilles tendon insertion site untouched.

METHODS

We retrospectively reviewed and compared the clinical and radiographic parameters of patients who underwent MIS-DCWCO (11 cases) or open Haglund resection (14 cases) between January 2012 and June 2019. The minimum duration of follow-up for inclusion was 18 months. We measured the calcaneal pitch, Meary's, Fowler-Philip, and Böhler's angles. Clinical outcomes were evaluated using the visual analogue scale (VAS) and Victorian Institute of Sports Assessment-Achilles (VISA-A) scores measured preoperatively and at 3, 6, 9, 12, and ≥18 months, postoperatively.

RESULTS

In both groups, the Meary's and calcaneal pitch angles did not change significantly, whereas the Fowler-Philip and Böhler's angles were significantly changed postoperatively. Significant improvements in VAS and VISA-A scores were observed in both groups (P < 0.001). The extent of correction of the four radiographic and two clinical parameters were not significantly different between the two groups. However, VAS and VISA-A scores at postoperative 6 months were significantly different, whereas these parameters were not significantly different at all other time points.

CONCLUSION

Both techniques provided similar postoperative clinical and radiographic improvement. However, MIS-DCWCO achieved earlier clinical improvement than open Haglund resection.

LEVEL OF EVIDENCE

Level III, comparative series.

Failed Surgery for Achilles Tendinopathy

Treatments of Achilles tendinopathy continue to evolve. The body of literature is inadequate to provide a comprehensive guide to evaluation and treat failed surgeries. Issues related to failed surgical treatment may be divided into infection/wound issue, mechanical failure, and persistent pain. Awareness of the potential problems described in this article will allow surgeons to have a foundation in clinical assessment and making accurate diagnoses. Various surgical treatment options are available and should be executed carefully to treat individualized patient conditions.

Inhibition of glucose use improves structural recovery of injured Achilles tendon in mice

Injured tendons do not regain their native structure except at fetal or very young ages. Healing tendons often show mucoid degeneration involving accumulation of sulfated glycosaminoglycans (GAGs), but its etiology and molecular base have not been studied substantially. We hypothesized that quality and quantity of gene expression involving the synthesis of proteoglycans having sulfated GAGs are altered in injured tendons and that a reduction in synthesis of sulfated GAGs improves structural and functional recovery of injured tendons. C57BL6/j mice were subjected to Achilles tendon tenotomy surgery. The injured tendons accumulated sulfate proteoglycans as early as 1-week postsurgery and continued so by 4-week postsurgery. Transcriptome analysis revealed upregulation of a wide range of proteoglycan genes that have sulfated GAGs in the injured tendons 1 and 3 weeks postsurgery. Genes critical for enzymatic reaction of initiation and elongation of chondroitin sulfate GAG chains were also upregulated. After the surgery, mice were treated with the 2-deoxy-d-glucose (2DG) that inhibits conversion of glucose to glucose-6-phosphate, an initial step of glucose metabolism as an energy source and precursors of monosaccharides of GAGs. The 2DG treatment reduced accumulation of sulfated proteoglycans, improved collagen fiber alignment, and reduced the cross-sectional area of the injured tendons. The modulus of the 2DG-treated groups was higher than that in the vehicle group, but not of statistical significance. Our findings suggest that mucoid degeneration in injured tendons may result from the upregulated expression of genes involved the synthesis of sulfate proteoglycans and can be inhibited by reduction of glucose utilization.

Prevalence of Achilles tendinopathy in physical exercise: A systematic review and meta-analysis

This comprehensive systematic review and meta-analysis assessed the prevalence of Achilles tendinopathy (AT) in physical exercise (PE). Specifically, we estimate the overall risk of AT in physical exercise and compare sport-specific estimates of AT risk. PubMed, Web of Science, Cochrane Library, and SPORTDiscus were searched before the 1^st of October 2021. Random-effects, subgroup analysis, sensitivity analysis and meta-regressions were conducted, involving 16 publications. This meta-analysis found that the overall prevalence of AT was 0.06 (95%CI, 0.04–0.07). The prevalence of Achilles tendon rupture was 0.03 (95%CI, 0.02–0.05). Subgroup analysis showed that the prevalence of AT increased with age, the highest among the group aged over 45 (0.08; 95%CI, 0.04–0.11), and the lowest among the group under 18 years old (0.02; 95%CI, 0.01–0.03). The gymnastics and ball games had the highest prevalence of AT, at (0.17; 95%CI, 0.14–0.20) and (0.06; 95%CI, 0.02–0.11), respectively. The prevalence of AT in athletes (0.06; 95%CI, 0.04–0.08) was higher than that of amateur exercisers (0.04; 95%CI, 0.02–0.06) and there was no difference in the prevalence of AT between males and females. There are differences in the prevalence of AT in different ages, sport events and characteristics of participants. This systematic review and meta-analysis suggested that it was necessary to pay more attention to AT in people who were older or engaged in gymnastics.

Causal Associations of Obesity With Achilles Tendinopathy: A Two-Sample Mendelian Randomization Study

BACKGROUND

Achilles tendinopathy (AT) is associated with severe pain and is the cause of dysfunction and disability that are associated with significant reduction in social and economic benefits. Several potential risk factors have been proposed to be responsible for AT development; however, the results of observational epidemiological studies remain controversial, presumably because the designs of these studies are subject to residual confounding and reverse causality. Mendelian randomization (MR) can infer the causality between exposure and disease outcomes using genetic variants as instrumental variables, and identification of the causal risk factors for AT is beneficial for early intervention. Thus, we employed the MR strategy to evaluate the causal associations between previously reported risk factors (anthropometric parameters, lifestyle factors, blood biomarkers, and systemic diseases) and the risk of AT.

METHODS

Univariable MR was performed to screen for potential causal associations between the putative risk factors and AT. Bidirectional MR was used to infer reverse causality. Multivariable MR was conducted to investigate the body mass index (BMI)-independent causal effect of other obesity-related traits, such as the waist-hip ratio, on AT.

RESULTS

Univariable MR analyses with the inverse-variance weighted method indicated that the genetically predicted BMI was significantly associated with the risk of AT (P=2.0×10^-3), and the odds ratios (95% confidence intervals) is 1.44 (1.14-1.81) per 1-SD increase in BMI. For the other tested risk factors, no causality with AT was identified using any of the MR methods. Bidirectional MR suggested that AT was not causally associated with BMI, and multivariable MR indicated that other anthropometric parameters included in this study were not likely to causally associate with the risk of AT after adjusting for BMI.

CONCLUSIONS

The causal association between BMI and AT risk suggests that weight control is a promising strategy for preventing AT and alleviating the corresponding disease burden.

Gastrocnemius release is an effective management option for Achilles tendinopathy: a systematic review

PURPOSE

This systematic review aims to summarise the outcomes of gastrocnemius release in the management of Achilles Tendinopathy.

METHODS

A systematic review was performed according to PRISMA guidelines. A computer-based search was performed in PubMed, Embase, Cinahl, Scopus and ISI Web of Science. Two independent reviewers performed both title/abstract and full-text screening according to a-priori selection criteria. English-language original research studies reporting outcomes for gastrocnemius recession in patients with Achilles tendinopathy were included. Study quality and risk of bias were assessed using the MINORS criteria.

RESULTS

Of the 229 articles identified following database searching, nine studies describing 145 cases of gastrocnemius recession were included in the review. Clinically important differences were reported across a range of validated patient reported outcome scores including VISA-A, FFI, FAAM and VAS pain score. Outcomes appear to be superior in patients with noninsertional Achilles tendinopathy, however further research is required to confirm this. Studies also reported an increase in ankle dorsiflexion range of motion and a good rate of return to sport/work. The overall complication rate was 10/123 (8.1%), with sural nerve injury being the most common complication, occurring in 5/123 (4.1%) of cases.

CONCLUSION

The results of this review suggest gastrocnemius release to be an effective treatment option in the management of patients with Achilles tendinopathy, who have gastrocnemius contracture and have previously failed to respond adequately to non-operative treatment.

LEVEL OF EVIDENCE

Level IV.

Cell autonomous TGFβ signaling is essential for stem/progenitor cell recruitment into degenerative tendons

Understanding cell recruitment in damaged tendons is critical for improvements in regenerative therapy. We recently reported that targeted disruption of transforming growth factor beta (TGFβ) type II receptor in the tendon cell lineage (Tgfbr2^ScxCre) resulted in resident tenocyte dedifferentiation and tendon deterioration in postnatal stages. Here we extend the analysis and identify direct recruitment of stem/progenitor cells into the degenerative mutant tendons. Cre-mediated lineage tracing indicates that these cells are not derived from tendon-ensheathing tissues or from a Scleraxis-expressing lineage, and they turned on tendon markers only upon entering the mutant tendons. Through immunohistochemistry and inducible gene deletion, we further find that the recruited cells originated from a Sox9-expressing lineage and their recruitment was dependent on cell autonomous TGFβ signaling. The cells identified in this study thus differ from previous reports of cell recruitment into injured tendons and suggest a critical role for TGFβ signaling in cell recruitment, providing insights that may support improvements in tendon repair.

•

Targeted deletion of TGFβ signaling led to degenerative changes in mouse tendons

•

Stem/progenitor cells were recruited into the degenerative mutant tendons

•

The recruited cells are different from the ones so far reported in tendon injury

•

Recruitment was dependent on cell autonomous TGFβ signaling in the recruited cells

The Efficacy of Acupuncture on Foot and Ankle for Pain Intensity, Functional Status, and General Quality of Life in Adults: A Systematic Review

Objective: To assess the effect of acupuncture on foot and ankle pain intensity, functional status, quality of life, and incidence of adverse events in adults. Methods: Randomized controlled trials (RCTs) were obtained from a systematic search of 6 major English databases, and a manual search of relevant systematic reviews using Google Scholar. RCTs that compared acupuncture with various forms of sham acupuncture, nonactive and waitlist controls for pain intensity, functional status, and general quality of life were included. Study screening, data extraction, risk of bias assessment, and quality assessment were all performed independently. A narrative synthesis was performed when quantitative pooling was inappropriate. Results: Four RCTs were included, encompassing a total of 211 participants. Due to clinical heterogeneity for all outcomes, quantitative analysis was not appropriate. Our Grades of Recommendation, Assessment, Development and Evaluation rated all outcomes to have either low or very low quality of evidence. With low-quality evidence, acupuncture was shown to be efficacious for participants with plantar fasciitis for pain relief and functional status improvement at short- and intermediate-term follow-ups. Acupuncture was also shown to be efficacious for participants with Achilles tendinopathy for pain relief at short- and intermediate-term follow-ups. No adverse events were reported. Conclusion: There is some evidence to suggest acupuncture to be a safe and efficacious treatment for relieving pain and improving functional status for the foot and ankle. The results of this systematic review should be interpreted with caution due to the limited evidence. Future research should take into consideration the findings of this systematic review.

Comparing Effectiveness of Combination of Collagen Peptide Type-1, Low Molecular Weight Chondroitin Sulphate, Sodium Hyaluronate, and Vitamin-C Versus Oral Diclofenac Sodium in Achilles Tendinopathy: A Prospective Randomized Control Trial

Background

Achilles tendinopathy, a common cause of heel pain, is primarily considered mechanical in origin, but its pathogenesis and treatment lack consensus. Molecules such as collagen peptide type-1, low molecular weight chondroitin sulphate, sodium hyaluronate and vitamin C have been shown to act as building blocks of tendon structure, and oral supplementation of these have promising results in Achilles tendinopathy.

Methods

This study was a prospective randomized control trial to compare the effectiveness of oral diclofenac sodium versus a nutraceutical combination of collagen peptide type-1, chondroitin sulphate, sodium hyaluronate, and vitamin C in the treatment of Achilles tendinopathy on pain and ultrasonographic structures. A total of 40 patients satisfying inclusion and exclusion criteria were randomly allocated into two groups and were given the nutraceutical combination in group A and diclofenac sodium in group B. The patient evaluation was done at baseline, six-week, and 12-week intervals in terms of VAS (Visual Analogue Scale) and tendo-Achilles thickness by ultrasound.

Results

Both nutraceutical combination and diclofenac reduced pain in persons with Achilles tendinopathy. The nutraceutical combination had a statistically significant better outcome in reducing pain at the end of 12 weeks. On ultrasound, both the interventions reduced Achilles tendon anteroposterior and mediolateral thickness by the end of 12 weeks. Although there was no absolute significant intergroup difference, the percentage change was more in the nutraceutical group in the case of anteroposterior thickness.

Conclusion

Combining collagen peptide type-1, low molecular weight chondroitin sulphate, sodium hyaluronate, and vitamin C is more effective than oral diclofenac in controlling pain in Achilles tendinopathy.

Adipose micro-grafts enhance tendinopathy healing in ovine model: An in vivo experimental perspective study

In Europe, approximatively 100 000 to 500 000 tendon repairs are performed every year. These procedures are associated with a considerable rate of postoperative complications (from 6% to 11%). Autologous micro‐grafts (AAMG) and stromal vascular fraction (SVF) have been shown to improve tendon healing in 60% to 70% of treated rodents. The purpose of this study was to evaluate the effects of AAMG in a sheep model with tendinopathy. We used sheep models because, as a large animal, they are more comparable to humans. The hypothesis was that SVF injection would improve tendon healing compared with the control group, reducing inflammatory and matrix degrading, while increasing anti‐inflammatory expression and collagen synthesis in the early stage of tendon injury. Sixteen Apennine sheep aged 2 to 5 years underwent 500 UI type I collagenase injection into both common calcaneal tendons (CCT) to induce tendinopathy. After 15 days (T0), one CCT in every ovine underwent randomly to 2.5 mL of AAMG obtained by mechanical disruption and the contralateral CCTs received no treatment. Clinical, ecographic, and sonographic evaluations were performed after 4 weeks (T1) and 8 weeks (T2). Histological, immunohistochemical, real‐time polymerase chain reaction (RT‐PCR), and biomechanical evaluations were performed at T2. At T2, the treated group showed a final tendon diameter (9.1 ± 1.4 mm) and a hardness expression (62%) that were similar to the original healthy tendon (8.1 ± 1.1 mm; 100%), with a significant recovery compared with the control group (9.5 ± 1.7 mm; 39%). Moreover, histological analysis of the treated group revealed an improvement in the fiber orientation score, fiber edema score, infiltrative‐inflammatory process, and necrosis score (4.3 ± 3.3) compared with control group (8.8 ± 2.9). Immunohistochemically, the treated group showed high expression of collagen 1, Factor VIII and significantly low expression of collagen 3. These data were confirmed by RT‐PCR analysis. The study findings suggested that AAMGs obtained through mechanical disruption present a safe, efficient, and reliable technique, enhancing tendon healing.

"Smart Exosomes": A Smart Approach for Tendon Regeneration

Shoulder tendon injuries are the common musculoskeletal disorder resulting in significant pain and disability. These injuries are characterized by chronic inflammation and tissue degeneration. Tendon pathology exhibits poor innate healing ability, enhanced inflammation, disorganized collagen fibers, calcification, and scar tissue formation affecting the normal healing process. Extracellular vesicle, especially exosomes, treatment has been emerging as a potential regenerative strategy improving the outcomes and biomechanical properties, accelerating tenocyte proliferation and migration, reducing inflammation, and facilitating the healing at tendon-bone interface. In this article, we critically reviewed the potential role of exosomes in tendon regeneration and their applications to accelerate the healing response following injury. In addition, the article provides novel insights on the concept of "Smart Exosomes" by programming/manipulating the secretome contents and functions of exosomes in the management of shoulder tendon injury.

Does the Calcaneus Serve as Hypomochlion within the Lower Limb by a Myofascial Connection?-A Systematic Review

(1) Background: Clinical approaches have depicted interconnectivity between the Achilles tendon and the plantar fascia. This concept has been applied in rehabilitation, prevention, and in conservative management plans, yet potential anatomical and histological connection is not fully understood. (2) Objective: To explore the possible explanation that the calcaneus acts as a hypomochlion. (3) Methods: 2 databases (Pubmed and Livivo) were searched and studies, including those that examined the relationship of the calcaneus to the Achilles tendon and plantar fascia and its biomechanical role. The included studies highlighted either the anatomical, histological, or biomechanical aspect of the lower limb. (4) Results: Seventeen studies were included. Some studies depicted an anatomical connection that slowly declines with age. Others mention a histological similarity and continuity via the paratenon, while a few papers have brought forward mechanical reasoning. (5) Conclusion: The concept of the calcaneus acting as a fulcrum in the lower limb can partially be supported by anatomical, histological, and biomechanical concepts. Despite the plethora of research, a comprehensive understanding is yet to be investigated. Further research exploring the precise interaction is necessary.

Outcomes of iliac crest bone marrow aspirate injection for the treatment of recalcitrant Achilles tendinopathy

BACKGROUND

Achilles tendinopathy is a common cause of posterior ankle and heel pain in both active and sedentary patients. Though the majority of patients respond to first-line non-operative management including activity modification, immobilization, orthotics, and physical therapy with stretching and eccentric strengthening, there is no consensus for patients who fail these treatments. We evaluate the role of iliac crest bone marrow aspirate (BMA) injections as a treatment option for recalcitrant cases.

METHODS

A retrospective chart review was conducted of patients with refractory Achilles tendinopathy treated with iliac crest BMA concentrate injection. Symptoms were assessed using the numeric rating system (NRS) pain score at the pre-operative visit and at six, 12, 24, and 48 weeks postoperatively. Post-operative complications were recorded.

RESULTS

A total of 15 patients (15 feet) with recalcitrant Achilles tendinopathy (5 insertional, 8 non-insertional, 2 combined) treated with iliac crest BMA concentrate injections were included in the study. Average age was 53.2 years (range, 25 to 64), average BMI was 27.1 kg/m² (range, 18.4 to 34.4), and average duration of symptoms prior to BMA injection was 2.3 years (range, 1 to 7). Pre-operatively, average NRS was 6.26 (95% CI, 5.04 to 7.49), with significant improvement at six weeks (mean, 4.26; 95% CI, 2.94 to 5.59; p = 0.04), ten weeks (mean, 4.13; 95% CI, 2.91 to 5.35; p = 0.012), 24 weeks (mean, 3.40; 95% CI, 2.05 to 4.75; p = 0.03), and 48 weeks (mean, 2.60; 95% CI, 1.14 to 4.06; p = 0.007) post-operatively. Overall, there was trending improvement over the 48-week follow-up period, with a mean improvement in NRS of - 3.22 (95% CI, - 1.06 to - 5.38; p = 0.007) at final follow-up. There was no discernable difference between insertional and non-insertional tendinopathy, and there were no incidences of post-operative complications.

CONCLUSION

Iliac crest BMA appears to be a safe, effective, and potentially lasting treatment option for patients with intractable, insertional and non-insertional Achilles tendinopathy. Patients demonstrated and maintained statistically significant decrease in NRS pain score post-operatively with no complications at the donor or injection site.

The Roles of MicroRNAs in Tendon Healing and Regeneration

Tendons connect the muscle abdomen of skeletal muscles to the bone, which transmits the force generated by the muscle abdomen contraction and pulls the bone into motion. Tendon injury is a common clinical condition occurring in certain populations, such as repeated tendon strains in athletes. And it can lead to substantial pain and loss of motor function, in severe cases, significant disability. Tendon healing and regeneration have attracted growing interests. Some treatments including growth factors, stem cell therapies and rehabilitation programs have been tried to improve tendon healing. However, the basic cellular biology and pathology of tendons are still not fully understood, and the management of tendon injury remains a considerable challenge. Regulating gene expression at post-transcriptional level, microRNA (miRNA) has been increasingly recognized as essential regulators in the biological processes of tendon healing and regeneration. A wide range of miRNAs in tendon injury have been shown to play vital roles in maintaining and regulating its physiological function, as well as regulating the tenogenic differentiation potential of stem cells. In this review, we show the summary of the latest information on the role of miRNAs in tendon healing and regeneration, and also discuss potentials for miRNA-directed diagnosis and therapy in tendon injuries and tendinopathy, which may provide new theoretical foundation for tenogenesis and tendon healing.

Gender Difference in Architectural and Mechanical Properties of Medial Gastrocnemius-Achilles Tendon Unit In Vivo

This study aims to explore whether gender differences exist in the architectural and mechanical properties of the medial gastrocnemius–Achilles tendon unit (gMTU) in vivo. Thirty-six healthy male and female adults without training experience and regular exercise habits were recruited. The architectural and mechanical properties of the gMTU were measured via an ultrasonography system and MyotonPRO, respectively. Independent t-tests were utilized to quantify the gender difference in the architectural and mechanical properties of the gMTU. In terms of architectural properties, the medial gastrocnemius (MG)’s pennation angle and thickness were greater in males than in females, whereas no substantial gender difference was observed in the MG’s fascicle length; the males possessed Achilles tendons (ATs) with a longer length and a greater cross-sectional area than females. In terms of mechanical properties, the MG’s vertical stiffness was lower and the MG’s logarithmic decrement was greater in females than in males. Both genders had no remarkable difference in the AT’s vertical stiffness and logarithmic decrement. Gender differences of individuals without training experience and regular exercise habits exist in the architectural and mechanical properties of the gMTU in vivo. The MG’s force-producing capacities, ankle torque, mechanical efficiency and peak power were higher in males than in females. The load-resisting capacities of AT were greater and the MG strain was lesser in males than in females. These findings suggest that males have better physical fitness, speed and performance in power-based sports events than females from the perspective of morphology and biomechanics.

Interplay of Forces and the Immune Response for Functional Tendon Regeneration

Tendon injury commonly occurs during sports activity, which may cause interruption or rapid decline in athletic career. Tensile strength, as one aspect of tendon biomechanical properties, is the main parameter of tendon function. Tendon injury will induce an immune response and cause the loss of tensile strength. Regulation of mechanical forces during tendon healing also changes immune response to improve regeneration. Here, the effects of internal/external forces and immune response on tendon regeneration are reviewed. The interaction between immune response and internal/external forces during tendon regeneration is critically examined and compared, in relation to other tissues. In conclusion, it is essential to maintain a fine balance between internal/external forces and immune response, to optimize tendon functional regeneration.

Factors associated with Achilles tendon pain in cyclists in eastern province of Saudi Arabia

BACKGROUND:

Cyclists are predisposed to different types of injuries whose patterns and distribution change over time. During bicycling, the high demand on lower extremities to produce speed places high load on the legs resulting in overuse injuries of which pain in the Achilles tendon is one. This study assessed Achilles tendon pain in cyclists in the eastern province of Saudi Arabia.

MATERIALS AND METHODS:

This was a cross-sectional study of active cyclists in the eastern province of Saudi Arabia. Data were collected using validated and pretested web-based self-administered questionnaire. Of the 511 cyclists invited, 311 completed the questionnaire yielding 60.62% response rate. SPSS was used for data entry and analysis. Descriptive statistics included calculation of frequencies and percentages for categorical variables, and median, mean and standard deviation for continuous variables. Chi-square test measured the associations between Achilles pain and various risk factors. Student's t-test, or Mann–Whitney test as appropriate, was used to compare continuous variables.

RESULTS:

Ten percent of mature and 9.1% professional cyclists reported that they had Achilles tendon pain. The pain was reported by significantly higher proportion of cyclists who raced (25%) and cyclists who rode mountain bicycles off-road (60.0%); average duration of the Achilles tendon pain was 7 days. Of the cyclists who had Achilles tendon pain, 32.1% reported that the pain increased when they were in running load and 28.6% reported increased pain in cycling load. Most cyclists described the pain as mild (67.9%) and moderate (32.1%). Overweight and underweight cyclists reported significantly higher rates of Achilles tendon pain (60% and 12.5%) compared to other body mass index classes.

CONCLUSION:

Achilles tendon pain commonly affects both amateur and professional cyclists. The study underpins the importance of a gradual increase in the training load, proper conditioning, bike fitting, and the maintenance of ideal body weight of cyclists to prevent Achilles tendon pain.

Curcuminoids and Boswellia serrata extracts combination decreases tendinopathy symptoms: findings from an open-label post-observational study

Background: To investigate the effects of 1-month treatment in addition to standard care with a food supplement containing both Curcuma longa and Boswellia serrata extracts on tendinopathy symptoms.Method: This open-label, non-controlled, post-observational study included 670 patients suffering from tendinopathy recruited at different sites by Belgian general practitioners. Patients received a medical prescription for 1-month treatment with two tablets twice a day of a pharmaceutical grade food supplement containing both C. longa and B. serrata extracts. Pain and functional limitation were evaluated using a visual analog scale at the inclusion and 1-month treatment later. Patient satisfaction, concomitant drugs intake and side effects were also recorded.Results: After 1-month treatment, pain and functional limitation were significantly improved whatever the cause of tendinopathy, its localization, and the duration of symptoms. The pain score decreased from 6.16 ± 1.53 to 2.98 ± 1.64 (p < .0001), yielding a drop of 51.6% and the functional limitation score fell after 1-month treatment from 5.96 ± 1.73 to 2.88 ± 1.67 (p < .0001) corresponding to a drop of 51.6%. The percentage of patients taking at least one concomitant treatment at the end of the treatment period had decreased from 81.3% to 61.8% (p < .0001). Only 43 (6.5%) patients reported side effects. No severe adverse effects related to the product were reported.Conclusion: The combination of C. longa and B. serrata extracts improves symptoms in patients suffering of tendinopathy and shows a good safety. Although its effect will have to be confirmed in randomized controlled trials, it can be considered as a helpful support of standard symptomatic treatments for tendinopathies. HighlightsTendinopathy is a common disease representing 30% of all consultations with a general practitioner for musculoskeletal disorders.The combination of Curcuminoids and Boswelliaserrata extracts are efficient on tendinopathy symptoms in support of standard symptomatic treatments.The combination of Curcuminoids and B. Serrata extract is safe and can be administrated for at least 1 month in addition of analgesic and non-steroidal anti-inflammatory drugs.

Surgical treatment for insertional Achilles tendinopathy and retrocalcaneal bursitis: more than 1 year of follow-up

OBJECTIVE

To analyse the imaging changes in bone marrow oedema of the calcaneal prominence, retrocalcaneal bursa and degenerative Achilles tendon after the surgical treatment of insertional Achilles tendinopathy (IAT).

METHODS

This retrospective study analysed patients with IAT and retrocalcaneal bursitis that were diagnosed based on their symptoms and radiographic and magnetic resonance imaging (MRI) examinations. For patients that had received 3 months of conservative treatment but still presented with symptoms, arthroscopic debridement of the retrocalcaneal bursa and resection of calcaneal prominence were undertaken. Patients with degeneration of the Achilles tendon underwent debridement of Achilles tendon calcification with an open incision. The last follow-up included radiographic and MRI imaging, Visual Analogue Scale (VAS) pain scores and American Orthopedic Foot and Ankle Society (AOFAS)-Ankle and Hindfoot scores.

RESULTS

Thirty patients were included (mean ± SD follow-up, 3.1 ± 0.5 years). The VAS pain and AOFAS-Ankle and Hindfoot scores were significantly improved after surgery. MRI showed that bone marrow oedema of the calcaneal prominence and the retrocalcaneal bursa was significantly reduced compared with preoperative values. There was no significant change in the high signal area of the IAT.

CONCLUSION

Surgical treatment of IAT and retrocalcaneal bursitis effectively alleviated local pain and restored function.

Flexor hallucis longus hypertrophy secondary to Achilles tendon tendinopathy: an MRI-based case-control study

PURPOSE

The purpose of this study was to outline an indirect sign of advanced Achilles tendinopathy on magnetic resonance imaging (MRI), based on the hypothesis that these patients would present with secondary hypertrophy of the flexor hallucis longus muscle (FHL).

METHODS

MRI scans of Achilles tendon were analyzed retrospectively in two cohorts. The study group consisted of consecutive patients presenting with clinical signs of Achilles tendinopathy and no previous surgeries, while the control group were patients that had an MRI due to other reasons and no signs of tendinopathy. Two parameters from two muscle bellies were measured and compared on axial MRI scans 4-5 cm above the ankle joint line at the level of greatest thickness: area and diameter of the triceps surae (TS) and of the FHL muscle. Ratios (FHL/TS) were calculated for area (Ar) and diameter (Dm) measurements. Interobserver agreement was analyzed. A receiver operating characteristic (ROC) curve was created for both ratios to assess potential cutoff points to differentiate between the groups.

RESULTS

A total of 60 patients for each study group were included. Both ratios Ar(FHL/TS) and Dm(FHL/TS) showed significant higher values in the tendinopathy group (p < 0.001). There were strong to very strong intraclass correlation coefficients (ICC = 0.75-0.93). A diameter ratio Dm (FHL/TS) of 2.0 or higher had a sensitivity of 49% and specificity of 90% for concomitant Achilles tendinopathy.

CONCLUSION

In our patient cohort, FHL hypertrophy was observed in patients with Achilles tendinopathy as a possible compensatory mechanism. Measuring a diameter ratio Dm(FHL/TS) of 2.0 or higher on an axial MRI, may be indicative as an indirect sign of functional deterioration of the Achilles tendon.

Extracorporeal shockwave therapy versus musculoskeletal mesotherapy for Achilles tendinopathy in athlete

Background

Achilles tendinopathy (AT) is considered the commonest tendon pathology, occurring mainly in athletes. Different conservative treatment options have been introduced but with short-term effects; however, extracorporeal shockwave therapy (ESWT) and mesotherapy (MT) injections were claimed to provide longer effects and could be used in cases failure of response to conservative treatments.

The objective of our prospective 12-week study was to compare the effect of ESWT and MT on chronic Achilles tendinopathy in athletes by both clinical and ultrasonographical assessment.

Results

Forty patients with chronic AT diagnosed clinically and with high-resolution ultrasound (US) randomly allocated in two groups first received weekly ESWT session, and the other group underwent weekly MT sessions for 4 consecutive weeks. Both groups improved during the treatment and follow-up period. The mean visual analogue score (VAS) decreased in both the ESWT group and the MT group. Mean American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score and VAS scores were not significantly different between ESWT and MT groups at the 4th and the 12th week of follow-up. However, US assessment significantly improved after 12 weeks in the ESWT group (as regards tendon thickness, calcifications, and Doppler signal), and for the mesotherapy group, there was the only improvement of tendon thickness.

Conclusion

ESWT showed improvement of pain and inflammation and calcifications of AT than MT injections, which was documented by US improved findings at week 12 follow up.

Nesfatin-1 Promotes the Osteogenic Differentiation of Tendon-Derived Stem Cells and the Pathogenesis of Heterotopic Ossification in Rat Tendons via the mTOR Pathway

Heterotopic ossification (HO) is a pathological condition involved in tendinopathy. Adipokines are known to play a key role in HO of tendinopathy. Nesfatin-1, an 82-amino acid adipokine is closely reportedly associated with diabetes mellitus (DM), which, in turn, is closely related to tendinopathy. In the present study, we aimed to investigate the effects of nesfatin-1 on the osteogenic differentiation of tendon-derived stem cells (TDSCs) and the pathogenesis of tendinopathy in rats. In vitro, TDSCs were incubated in osteogenic induction medium for 14 days with different nesfatin-1 concentration. In vivo, Sprague Dawley rats underwent Achilles tenotomy to evaluate the effect of nesfatin-1 on tendinopathy. Our results showed that the expression of nesfatin-1 expression in tendinopathy patients was significantly higher than that in healthy subjects. Nesfatin-1 affected the cytoskeleton and reduced the migration ability of TDSCs in vitro. Furthermore, nesfatin-1 inhibited the expression of Scx, Mkx, and Tnmd and promoted the expression of osteogenic genes, such as COL1a1, ALP, and RUNX2; these results suggested that nesfatin-1 inhibits cell migration, adversely impacts tendon phenotype, promotes osteogenic differentiation of TDSCs and the pathogenesis of HO in rat tendons. Moreover, we observed that nesfatin-1 suppressed autophagy and activated the mammalian target of rapamycin (mTOR) pathway both in vitro and in vivo. The suppression of the mTOR pathway alleviated nesfatin-1-induced HO development in rat tendons. Thus, nesfatin-1 promotes the osteogenic differentiation of TDSC and the pathogenesis of HO in rat tendons via the mTOR pathway; these findings highlight a new potential therapeutic target for tendinopathy.

Suture Anchor Versus Allogenic Tendon Suture in Treatment of Haglund Syndrome

Background

Haglund’s deformity is an abnormal bony enlargement on the back of the heel. It can cause the impact of the posterior calcaneal bursa and Achilles tendon insertion, and finally result in pain. This syndrome is called Haglund syndrome. The purpose of this study was to explore the effect of the suture anchor and allogeneic tendon suture in the treatment of Haglund syndrome.

Material/Methods

We retrospectively studied 20 patients with Haglund syndrome treated from January 2015 to December 2016. The patients were randomly divided into Group 1 (the suture anchor group) and Group 2 (the allogeneic tendon group), with 10 patients in each group and an average follow-up of 32 months after surgery. The AOFAS, VAS, and Arner-Lindholm scales were used to summarize the patient follow-up results and complications.

Results

In the 2 groups of patients, the postoperative AOFAS, VAS scores, and the Arner-Lindholm scale showed good results. However, the postoperative AOFAS score and VAS of the suture anchor group were better than those of the allogeneic tendon group, with shorter operation times. No Achilles tendon rupture or wound infection occurred during the entire postoperative period in either group. These results show the superiority of suture anchors.

Conclusions

The higher AOFAS and VAS score and shorter operation time in the suture anchor group suggest it is the better alternative for treatment of Haglund syndrome.

Photobiomodulation therapy on expression of HSP70 protein and tissue repair in experimental acute Achilles tendinitis

The aim of the present study was to investigate the effects of photobiomodulation (PBM) therapy on the expression of heat shock protein 70 (HSP70) and tissue repair in an experimental model of collagenase-induced Achilles tendinitis. Thirty Wistar rats (aged 12 weeks) were randomly distributed among control group (n = 8), tendinitis group (n = 11), and LED group (n = 11). Tendinitis was induced in the tendinitis and LED groups through a peritendinous injection of collagenase (100 μl). The LED group animals received the first irradiation 1 h after injury. A 630 ± 20 nm, 300-mW continuous wave light-emitting diode (LED), spot size 1 cm², was placed in contact with the skin. One point over the tendon was irradiated for 30 s, delivering 9 J (9 J/cm²). LED irradiation was performed once daily for 7 days, with the total energy delivered being 63 J. The tendons were surgically removed and expression of the HSP70 protein was calculated using semi-quantitative analyses of immunohistochemistry (HSCORE). Number of fibroblasts and amount of collagen were measured using histological and histochemical analyses. An increase in the mean HSCORE for HSP70, in the number of fibroblasts, and in the amount of collagen were found in the LED group compared with those in the tendinitis and control group (P ≤ 0.05). PBM therapy increased the expression of the HSP70, number of fibroblasts, and amount of collagen in the acute Achilles tendinitis in rats.

Comparative Efficacy and Tolerability of Nonsurgical Therapies for the Treatment of Midportion Achilles Tendinopathy: A Systematic Review With Network Meta-analysis

Background:

Achilles tendinopathy (AT) is a common cause of overuse injury in both athletes and nonactive individuals, especially at older ages. Due to the limited number of direct comparisons among interventions, determining the best treatment option can be difficult.

Purpose:

To evaluate the comparative efficacy and tolerability of nonsurgical therapies for midportion AT.

Study Design:

Systematic review; Level of evidence, 1.

Methods:

PubMed, MEDLINE, EMBASE, and Google Scholar were searched from database inception through June 20, 2019. Randomized controlled trials investigating the effect of nonsurgical therapies for midportion AT using the Victorian Institute of Sports Assessment–Achilles (VISA-A) assessment were eligible for inclusion. Primary outcome was mean change in VISA-A score from baseline. Comparisons between interventions were made through use of random-effects network meta-analysis over the short term (≤3 months) and longer term (>3 to <12 months). A safety profile was defined for each intervention by rate of all-cause discontinuation (dropout) during follow-up. Relative ranking of therapies was assessed by the surface-under-the–cumulative ranking possibilities.

Results:

A total of 22 studies with 978 patients met the inclusion criteria. In short-term studies, high-volume injection with corticosteroid (HVI+C) along with eccentric exercise (ECC) significantly improved the change of VISA-A score compared with that of ECC alone (standardized mean difference [SMD], 1.08; 95% CI, 0.58-1.58). Compared with ECC, acupuncture showed benefits over both the short term (SMD, 1.57; 95% CI, 1.00-2.13) and longer term (SMD, 1.23; 95% CI, 0.69-1.76). In longer-term studies, the wait-and-see approach resulted in unfavorable outcomes compared with ECC (SMD, −1.51; 95% CI, −2.02 to −1.01). Improvement was higher when ECC was combined with HVI+C (SMD, 0.53; 95% CI, 0.05-1.02) and extracorporeal shockwave therapy (ESWT) (SMD, 0.99; 95% CI, 0.48-1.49). All interventions had a similar safety profile.

Conclusion:

From available high-level studies, HVI+C and ESWT may be possible interventions to add along with ECC to improve longer-term outcomes.

Comparison on effects of platelet-rich plasma versus autologous conditioned serum on Achilles tendon healing in a rat model

OBJECTIVE

The aim of this study was to compare the effects of local administrations of platelet-rich plasma (PRP) with autologous conditioned serum (ACS) on Achilles tendon healing in a rat model.

METHODS

In this study, 40 male Sprague-Dawley rats, aged 12 months and weighing 350 to 400 g were used. The rats were divided into three groups (n=10 in each group): a control group and two treatment groups (PRP vs ACS). A standardized procedure was applied for the complete rupture and repair of the Achilles tendon in each group. The PRP group received one dose of PRP on the operative area, and ACS group received ACS at 24, 48, and 72 hours after the surgery. The control group received no injection. Animals were sacrificed 30 days after the operation, and tendon healing in each group was assessed histopathologically based on Bonar's semi-quantitative score and Movin's semi-quantitative grading scale. For the biomechanical analyses, unoperated Achilles tendons of all rats in the control and ACS groups were also harvested, and pulling tests were applied to the specimen to measure the longitudinal axis strength. The highest force value among the data obtained was defined as the maximum strength value (Fmax).

RESULTS

The mean Bonar's score was significantly lower in the PRP group (3.8±0.8) than in the ACS (4.8±0.45) and control groups (5.2±0.837) (p=0.0028). The mean Movin's score was significantly lower in the PRP group (7.80±1.49) than in the ACS (9.8±1) and control groups (11.2±2.4) (p=0.029). The ratio of type I collagen was significantly higher in the PRP group (60±6) than in the ACS (52±4.5) and control groups (42±9) (p=0.005). Biomechanical results obtained from operated sites were comparable in terms of Fmax among groups (PRP, 33.93±2.61; ACS, 35.24±3.26; control, 35.69±3.62) (p=0.674). Similarly, the results obtained from unoperated sites were comparable among groups (PRP, 47.71±1.21; ACS, 48.14±2; control, 49.14.69±1.88) (p=0.395).

CONCLUSION

In terms of histopathological results, PRP seems to be more effective than ACS for Achilles tendon healing in rats.

Comparison of dorsal closing wedge calcaneal osteotomy versus posterosuperior prominence resection for the treatment of Haglund syndrome

Background

Haglund syndrome is a common disease that causes posterior heel pain. This study compared the clinical outcomes of dorsal closing wedge calcaneal osteotomy (DCWCO) and posterosuperior prominence resection (PPR) for the treatment of Haglund syndrome.

Methods

This retrospective study included 12 patients who underwent DCWCO and 32 patients who underwent PPR from January 2010 to August 2016. Patients were evaluated using the American Orthopedic Foot Ankle Society ankle-hindfoot scale (AOFAS), Victorian Institute of Sport Assessment Scale for Achilles tendinopathy (VISA-A), Fowler-Philip angle, Bohler’s angle, and calcaneal pitch angle preoperatively and postoperatively (at 3 months, 6 months, 1 year, and the latest follow-up).

Results

Both groups exhibited a significant increase in their AOFAS and VISA-A scores after surgery. The DCWCO group had lower AOFAS scores than the PPR group at 6 months (77.6 ± 5.1 vs. 82.8 ± 7.8; P = 0.037) but had higher scores at the latest follow-up (98.2 ± 2.3 vs. 93.4 ± 6.1; P = 0.030). The DCWCO group had lower VISA-A scores at 3 months (56.9 ± 13.9 vs. 65.2 ± 11.0; P = 0.044) but higher scores at the latest follow-up (98.2 ± 2.6 vs. 94.3 ± 5.0; P = 0.010) than the PPR group. Both groups exhibited significant changes in the Fowler-Philip angle and Bohler’s angle after surgery. The postoperative Fowler-Philip angle of the DCWCO group was greater than that of the PPR group (35.9° ± 4.9° vs. 31.4° ± 6.2°; P = 0.026). However, there was no statistically significant difference in any other angle of the two groups postoperatively.

Conclusions

Compared to the PPR group, the DCWCO group had poorer short-term clinical outcomes but provide better long-term function and symptom remission. This method can be a good option for those patients with higher functional expectations.

Role of Biomaterials and Controlled Architecture on Tendon/Ligament Repair and Regeneration

Engineering synthetic scaffolds to repair and regenerate ruptured native tendon and ligament (T/L) tissues is a significant engineering challenge due to the need to satisfy both the unique biological and biomechanical properties of these tissues. Long-term clinical outcomes of synthetic scaffolds relying solely on high uniaxial tensile strength are poor with high rates of implant rupture and synovitis. Ideal biomaterials for T/L repair and regeneration need to possess the appropriate biological and biomechanical properties necessary for the successful repair and regeneration of ruptured tendon and ligament tissues.

Photobiomodulation with low-level laser therapy for treating Achilles tendinopathy: a systematic review and meta-analysis

Objective:

The purpose of this study was to determine the benefits and harms of low-level laser therapy for Achilles tendinopathy.

Data sources:

Search strategies were conducted (from inception to February 2020) in Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Literatura Latino Americana em Ciências da Saúde e do Caribe (LILACS), Physiotherapy Evidence Database (PEDro), SPORTDiscus, ClinicalTrials.gov, World Health Organization (WHO)-ICTRP and OpenGrey databases, to retrieve all randomized controlled trials that compared laser therapy with inactive/active interventions.

Review methods:

This study was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The risk of bias was assessed using the Cochrane Risk of bias table. Meta-analyses were performed on dependence of homogeneity, otherwise results were reported narratively. The certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results:

Four trials (119 participants) were analyzed. Laser therapy associated to eccentric exercises when compared to eccentric exercises and sham had very low to low certainty of evidence in pain and function assessment. Despite one trial favored laser therapy at two months (mean difference (MD) −2.55, 95% confidence interval (95% CI) −3.87 to −1.23), the CIs did not include important differences between groups at 3 and 13 months. The function assessment showed an improvement favoring the placebo group at one month (MD 9.19, 95% CI −16.16 to −2.23) and non-significant difference between groups at 3 and 13 months. Adverse events were poorly reported but restricted to minor events related to the exercises.

Conclusion:

The certainty of evidence was low to very low, and the results are insufficient to support the routine use laser therapy for Achilles tendinopathy.