Achilles Tendinopathy

Achilles tendon debridement, calcaneoplasty and double-row tendon footprint reconstruction improve ankle function and athletic performance in patients with insertional Achilles tendinopathy

BACKGROUND

Insertional Achilles tendinopathy is a frequent condition among physically active individuals. Extensive intratendinous pathologies may require partial tendon detachment, debridement and reconstruction of the tendon footprint. Positive functional outcomes are reported after the procedure, but literature on postoperative sport function is limited.

METHODS

Pre- and postoperative sports capability and ankle function were assessed in 25 patients undergoing Achilles tendon debridement and double-row footprint reconstruction.

RESULTS

The mean VAS score for pain during sport decreased significantly from 7.4 (SD, 2.5) to 1.2 (SD, 2.0) postoperatively (p < 0.001). Sports ability and subjective fitness levels increased significantly from 3.6 (SD 3.0) and 3.5 (2.2) to 8.8 (2.4) and 8.8 (2.2), respectively (p < 0.001). A trend from high-impact sports to low-impact sports was observed postoperatively. The subjective surgical outcome was good or excellent in 96 %.

CONCLUSION

Our study shows improvement in postoperative sports ability and high patient satisfaction after insertional Achilles tendon debridement, and double-row tendon footprint reconstruction.

LEVEL OF EVIDENCE

Level IV - retrospective case series.

Endoscopic peroneus brevis tendon transfer for chronic ruptures of the Achilles tendon: surgical technique

Chronic Achilles tendon rupture is usually defined as a rupture diagnosed 4-6 weeks after injury. The management of chronic Achilles tendon rupture (CATR) is a topic of hot debate, and no consensus has been achieved. Surgical management of CATR is recommended. Several approaches, techniques, and grafts have been described. Open techniques carry a high risk of wound breakdown, infection, and necessitate long rehabilitation times. Surgical techniques with smaller incisions to reduce the risk of scar fibrosis, pain, and infection are becoming common. The ipsilateral tendon of the hallux flexor longus and the peroneus brevis is commonly used. Endoscopic transfer of the peroneus brevis tendon is an innovative alternative to other procedures, with comparable results of other autografts even in elite athletes. The tendon of the peroneus brevis is harvested by tendoscopy before performing a calcaneal tendon endoscopy and fixing the graft in a calcaneal tunnel using an interference screw. After surgery, an anterior splint is placed for 3 weeks with immediate forefoot weight bearing. The rehabilitation starts on the 15th postoperative day.

Relationship Between Achilles Tendon Stiffness Using Myoton PRO and Translation Using a Tensile Testing Machine: A Biomechanical Study of a Porcine Model

Background Achilles tendinopathy is a common ankle disorder in both the general population and athletes. This condition can alter the mechanical characteristics of the Achilles tendon (AT) by decreasing tendon stiffness. Achilles tendinopathy is primarily treated conservatively; however, few monitoring tools exist for evaluating the condition of the AT. The Myoton PRO (Myoton AS, Tallinn, Estonia) device is a handheld tool used to evaluate tissue stiffness. However, no basic studies have examined the validity of Myoton PRO for assessing the AT. This study aimed to assess the validity of Myoton PRO using animal ATs and to examine its clinical applicability. Methods We used 28 fresh porcine ankles and evaluated AT stiffness at the calcaneus insertion site (AT0) and 2.0 cm above the calcaneus (AT2) using Myoton PRO. We also measured changes in the AT length using a tensile testing machine during the cyclic loading test. We investigated the correlation between dynamic stiffness and length change. Furthermore, we assessed the difference in stiffness between AT0 and AT2. Results The dynamic stiffness was 717.6 ± 183.1 N/m at AT0 and 467.4 ± 152.3 N/m at AT2. The change in length during the cyclic loading test was 1.8 ± 0.7 mm. The correlation between dynamic stiffness and length change was as follows: AT0, r=-0.61; AT2, r=-0.64 (P<0.001). The dynamic stiffness at AT0 was significantly greater than that at AT2 (P<0.001). Conclusions AT assessment using Myoton PRO has potential clinical utility as an indicator of tissue stiffness.

Recent advances in fluorescence imaging-guided photothermal therapy and photodynamic therapy for cancer: From near-infrared-I to near-infrared-II

Phototherapy (including photothermal therapy, PTT; and photodynamic therapy, PDT) has been widely used for cancer treatment, but conventional PTT/PDT show limited therapeutic effects due to the lack of disease recognition ability. The integration of fluorescence imaging with PTT/PDT can reveal tumor locations in a real-time manner, holding great potential in early diagnosis and precision treatment of cancers. However, the traditional fluorescence imaging in the visible and near-infrared-I regions (VIS/NIR-I, 400-900 nm) might be interfered by the scattering and autofluorescence from tissues, leading to a low imaging resolution and high false positive rate. The deeper near-infrared-II (NIR-II, 1000-1700 nm) fluorescence imaging can address these interferences. Combining NIR-II fluorescence imaging with PTT/PDT can significantly improve the accuracy of tumor theranostics and minimize damages to normal tissues. This review summarized recent advances in tumor PTT/PDT and NIR-II fluorophores, especially discussed achievements, challenges and prospects around NIR-II fluorescence imaging-guided PTT/PDT for cancers.

Achilles Tendinopathy Pathogenesis and Management: A Narrative Review

The Achilles tendon is the thickest and strongest tendon of the human body, and it is frequently injured during sports activity. The incidence of Achilles tendon pathologies has increased over recent decades, especially in the last few years, because of increased sports participation among the general population and due to the diffusion of competitive sports at a high level. Tendinopathies are common in athletes and in middle-aged overweight patients. The term "tendinopathy" refers to a condition characterised clinically by pain and swelling, with functional limitations of tendon and nearby structures, and consequently to chronic failure of healing response process. Tendinopathies can produce marked morbidity, and at present, scientifically validated management modalities are limited. Despite the constantly increasing interest and number of studies about Achilles tendinopathy (AT), there is still not a consensual point of view on which is the best treatment, and its management is still controversial. AT can be treated conservatively primarily, with acceptable results and clinical outcomes. When this approach fails, surgery should be considered. Several surgical procedures have been described for both conditions with a relatively high rate of success with few complications and the decision for treatment in patients with AT should be tailored on patient's needs and level of activity. The aim of this article is to give insights about the pathogenesis and most used and recent treatment options for AT.

Level of Evidence for the Treatment of Chronic Noninsertional Achilles Tendinopathy

BACKGROUND

Noninsertional Achilles tendinopathy affects both athletes and sedentary individuals, and its incidence is rising. Conservative management is the mainstay of treatment, but a variety of operative techniques have been described to treat recalcitrant cases. We seek to outline the current available evidence for surgical management of noninsertional Achilles tendinopathy.

STUDY DESIGN AND METHODS

A systematic review was performed using the MEDLINE and EMBASE databases, and all articles were reviewed by at least 2 authors. Each article was assigned a level of evidence in accordance with the standards of Journal of Bone and Joint Surgery. The available data were reviewed and a level of evidence was assigned to each intervention of interest, based on the revised classifications of Wright.

RESULTS AND CONCLUSION

A total of 46 articles met inclusion and exclusion criteria. There is fair evidence (grade B) in support of open debridement with 1 level II study, 1 level III study, and 8 level IV studies. There is fair evidence (grade B) in support of arthroscopic or minimally invasive surgical techniques. There is poor evidence (grade C) in support of flexor hallucis longus transfer, longitudinal tenotomy, peritenolysis, gastrocnemius recession, and plantaris excision. There is insufficient evidence (grade I) to provide a recommendation about other surgical treatment methods for noninsertional Achilles tendinopathy.Levels of Evidence: Level III: Systematic review.

Return to Play Following Achilles Tendon Rupture in NFL Players Based on Position

BACKGROUND

The purpose of this study was to determine the return-to-play (RTP) rate and postinjury performance after Achilles tendon (AT) ruptures in National Football League (NFL) skill position players.

METHODS

The study included NFL skill positions with an AT rupture between the 2009-2010 and 2015-2016 seasons. Performance data were collected and compared against a matched control group. RTP was defined as playing in at least 1 game after repair.

RESULTS

RTP rate was 57% for the study cohort. The tight ends (TEs) had the highest RTP rate at 71% while the wide receivers (WRs) had the lowest RTP rate at 38%. Compared with the control group, WRs with successful RTP had significantly less receptions per game (P = .01). For defensive players with RTP there were significant decreases in postrepair performance in tackles, passes defended, and fumbles forced/recovered compared with the control group.

CONCLUSION

A total of 57% of players achieved RTP with WRs and running backs (RBs) having the lowest RTP rates and TEs and linebackers (LBs) having the highest RTP rates. RBs, defensive backs (DBs), and LBs with successful RTP had decreased performance in all categories. This updated information may be helpful for athletes, physicians, scouts, and coaches in evaluating players with a history of AT rupture.

LEVELS OF EVIDENCE

Analytic, level 3, retrospective cohort study, Epidemiologic study.

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.

Morphometric Analysis of Achilles Tendon Structure and Its Significance: A Cadaveric Study

INTRODUCTION

Achilles tendon is crucial for gait, and chronic Achilles tendinopathy can have a substantial impact on an individual's work and active involvement in physical or sports activity, and overall quality of life.

OBJECTIVES

This research was to determine the macroscopic and microscopic anatomy of Achilles tendons in cadavers.

MATERIALS AND METHODS

This experimental study was conducted in the Department of Anatomy, Saveetha Medical College, Thandalam, from March to August 2022. A total of 60 formalin-perfused cadavers (38 males and 22 females) were dissected to study their morphometry (length, width, thickness) and histology. The data was tabulated in MS excel and analyzed statistically using unpaired 't-test and one-way ANOVA in SPSS Software 17.0 (IBM Corp., Armonk, NY).

RESULTS

The mean length of the Achilles tendon was significantly higher in males than in females and similarly, the length on the right side was significantly higher than on the left side (p<0.005). The width and circumference were statistically higher in females than, males whereas, the histological features were similar in both males and females.

CONCLUSION

The better understanding of Achilles tendon morphometry in cadavers always aids in the diagnosis and surgical repair of tendinopathy, rupture, and degenerative change. The knowledge will be helpful for the surgeons during the repair and reconstruction of the injured tendon.

Artificial-Intelligence-Based Imaging Analysis of Stem Cells: A Systematic Scoping Review

Simple Summary

Lately, investigations of artificial intelligence as an assisting tool for analyzing and identifying stem cells have increased. In this systematic scoping review, we aimed to identify and map the available artificial-intelligence-based techniques for imaging analysis, the characterization of stem cell differentiation, and trans-differentiation pathways. After an extensive search for the literature following a structured methodology, we included 27 studies in our systematic scoping review that we extracted the relevant data from. Based on the results of the included studies, artificial intelligence has the potential to serve as an assisting tool in stem cell imaging. However, it is still considered relatively new and under maturation. The goal of our review is to guide and help researchers while planning for future investigations.

Abstract

This systematic scoping review aims to map and identify the available artificial-intelligence-based techniques for imaging analysis, the characterization of stem cell differentiation, and trans-differentiation pathways. On the ninth of March 2022, data were collected from five electronic databases (PubMed, Medline, Web of Science, Cochrane, and Scopus) and manual citation searching; all data were gathered in Zotero 5.0. A total of 4422 articles were collected after deduplication; only twenty-seven studies were included in this systematic scoping review after a two-phase screening against inclusion criteria by two independent reviewers. The amount of research in this field is significantly increasing over the years. While the current state of artificial intelligence (AI) can tackle a multitude of medical problems, the consensus amongst researchers remains that AI still falls short in multiple ways that investigators should examine, ranging from the quality of images used in training sets and appropriate sample size, as well as the unexpected events that may occur which the algorithm cannot predict.

Cadaveric and Ultrasound Validation of Percutaneous Electrolysis Approach at the Achilles Tendon as a Potential Treatment for Achilles Tendinopathy: A Pilot Study

Achilles tendon tendinopathy (AT) is a musculoskeletal condition characterized by pain in the Achilles tendon and impaired physical performance or sport activities. AT is difficult to treat, and the results are variable. Preliminary evidence suggests a positive effect for pain of percutaneous electrolysis in patients with tendinopathy. Our aim was to determine the validity and safety of a percutaneous electrolysis approach targeting the interphase between the Achilles tendon and the Kager's fat with ultrasound imaging in both healthy individuals and on a fresh cadaver model (not ultrasound guiding). A needle was inserted from the medial to the lateral side under the body of the Achilles tendon, just between the tendon and the Kager's triangle, about 5 cm from the insertion of tendon in the calcaneus in 10 healthy volunteers (ultrasound study) and 10 fresh cadaver legs. An accurate needle penetration of the interphase was observed in 100% of the approaches, in both human and cadaveric models. No neurovascular bundle of the sural nerve was pierced in any insertion. The distance from the tip of the needle to the sural nerve was 5.28 ± 0.7 mms in the cadavers and 4.95 ± 0.68 mms in the volunteer subjects, measured in both cases at a distance of 5 cm from the insertion of the Achilles tendon. The results of the current study support that percutaneous electrolysis can be safely performed at the Kager's fat-Achilles tendon interphase if it is US guided. In fact, penetration of the sural nerve was not observed in any needle approach when percutaneous needling electrolysis was performed by an experienced clinician. Future studies investigating the clinical effectiveness of the proposed intervention are needed.

Evaluation of Sodium Relaxation Times and Concentrations in the Achilles Tendon Using MRI

Sodium magnetic resonance imaging (MRI) can be used to evaluate the change in the proteoglycan content in Achilles tendons (ATs) of patients with different AT pathologies by measuring the ²³Na signal-to-noise ratio (SNR). As ²³Na SNR alone is difficult to compare between different studies, because of the high influence of hardware configurations and sequence settings on the SNR, we further set out to measure the apparent tissue sodium content (aTSC) in the AT as a better comparable parameter. Ten healthy controls and one patient with tendinopathy in the AT were examined using a clinical 3 Tesla (T) MRI scanner in conjunction with a dual tuned ¹H/²³Na surface coil to measure ²³Na SNR and aTSC in their ATs. ²³Na T₁ and T₂* of the AT were also measured for three controls to correct for different relaxation behavior. The results were as follows: ²³Na SNR = 11.7 ± 2.2, aTSC = 82.2 ± 13.9 mM, ²³Na T₁ = 20.4 ± 2.4 ms, ²³Na T_2s* = 1.4 ± 0.4 ms, and ²³Na T_2l* = 13.9 ± 0.8 ms for the whole AT of healthy controls with significant regional differences. These are the first reported aTSCs and ²³Na relaxation times for the AT using sodium MRI and may serve for future comparability in different studies regarding examinations of diseased ATs with sodium MRI.

Scavenging of reactive oxygen species can adjust the differentiation of tendon stem cells and progenitor cells and prevent ectopic calcification in tendinopathy

Tendinopathy is a common disorder that leads to pain and impaired quality of life. Recent studies revealed that osteogenic differentiation of tendon stem/progenitor cells (TSPCs) played an important role in the pathogenesis of tendon calcification and tendinopathy. In this study, we found that the growth hormone-releasing hormone agonist (GA) can prevent matrix degradation and osteogenic differentiation in TSPCs. As oxidative stress is a key factor in the osteogenic differentiation of TSPCs, we used bovine serum albumin/heparin nanoparticles (BHNPs), which have biocompatibility and drug loading capacity, to scavenge reactive oxygen species (ROS) and achieve sustained release of GA at the site of inflammation. The newly developed BHNPs@GA had a synergetic effect on reducing ROS production in TSPCs. In addition, BHNPs@GA effectively inhibited tendon calcification and promoted collagen formation in a rat model of tendinopathy. Focusing on the ROS underlying the differentiation and dedifferentiation of TSPCs, this work demonstrated that sustained release of GA targeting ROS and ectopic ossification is a practical therapeutic strategy for treating tendinopathy. STATEMENT OF SIGNIFICANCE: Osteogenic differentiation of tendon stem/progenitor cells (TSPCs) plays an important role in the pathogenesis of ectopic calcification in tendinopathy. In this study, we found that growth hormone-releasing hormone agonist (GA) can reduce reactive oxygen species (ROS) production and adjust TSPCs differentiation. Bovine serum albumin/heparin nanoparticles (BHNPs) were developed to encapsulate GA and achieve sustained release of GA at the site of inflammation. The developed compound, BHNPs@GA, with a synergistic effect of inhibiting ROS and thus, can effectively adjust TSPCs differentiation, inhibit tendon calcification, and promote collagen formation in tendinopathy. This study highlighted the role of ROS underlying the differentiation and dedifferentiation of TSPCs in tendinopathy, and findings may help to identify new therapeutic targets and develop novel strategy for treating tendinopathy.

Bioactive extracellular matrix fragments in tendon repair

Tendinopathy is a common tendon disorder that causes pain, loss of strength and function, and local inflammation mainly characterized by hypoxia, collagen degradation, and extracellular matrix (ECM) disorganization. Generally, ECM degradation and remodeling is tightly regulated; however, hyperactivation of matrix metalloproteases (MMPs) contributes to excessive collagenolysis under pathologic conditions resulting in tendon ECM degradation. This review article focuses on the production, function, and signaling of matrikines for tendon regeneration following injury with insights into the expression, tissue compliance, and cell proliferation exhibited by various matrikines. Furthermore, the regenerative properties suggest translational significance of matrikines to improve the outcomes post-injury by assisting with tendon healing.

Neuromuscular and structural tendon adaptations after 6 weeks of either concentric or eccentric exercise in individuals with non-insertional Achilles tendinopathy: protocol for a randomised controlled trial

INTRODUCTION

There is limited evidence on the neural strategies employed by the central nervous system to control muscle force in the presence of non-insertional Achilles tendinopathy (NIAT). Additionally, the neuromuscular mechanisms by which exercise may help to resolve tendon pain remain unclear.

OBJECTIVE

This study aims to first establish changes in the gastrocnemius-soleus motor unit firing properties after applying a training protocol of 6 weeks based on either controlled eccentric or concentric contractions in individuals with NIAT. Second, we want to determine changes in the level of pain and function and mechanical and structural properties of the Achilles tendon after applying the same training protocol. Additionally, we want to compare these variables at baseline between individuals with NIAT and asymptomatic controls.

METHODS AND ANALYSIS

A total of 26 individuals with chronic (>3 months) NIAT and 13 healthy controls will participate in the study. Individuals with NIAT will be randomised to perform eccentric or concentric training for 6 weeks. Motor unit firing properties of the medial gastrocnemius, lateral gastrocnemius and soleus muscles will be assessed using high-density surface electromyography, as well as Achilles tendon length, cross-sectional area, thickness and stiffness using B-mode ultrasonography and shear wave elastography. Moreover, participants will complete a battery of questionnaires to document their level of pain and function.

ETHICS AND DISSEMINATION

Ethical approval (ERN-20-0604A) for the study was obtained from the Science, Technology, Engineering and Mathematics Ethical Review Committee of the University of Birmingham. The results of the study will be published in peer-review journals.

TRIAL REGISTRATION NUMBER

ISRCTN46462385.

The Effectiveness of Extracorporeal Shockwave Therapy for Midportion Achilles Tendinopathy: A Systematic Review

Achilles tendinopathy is one of the most common lower limb injuries in both athletes and the general population. Despite the plethora of conservative treatment options available for the management of Achilles tendinopathy, as many as one in four patients will go on to require surgery. Extracorporeal shockwave therapy (ESWT) has emerged as a promising treatment option and has been successful in the management of other common musculoskeletal injuries such as plantar fasciitis. However, the evidence for ESWT in the management of Achilles tendinopathy remains inconclusive. Therefore, the aim of this systematic review was to evaluate the current evidence for the use of ESWT in the management of midportion Achilles tendinopathy.

A comprehensive literature search was conducted using the databases MEDLINE (Pubmed), AMED, EMBASE, CINAHL, and CENTRAL. The databases were searched from their inception to December 2021. This was conducted to identify randomised control trials (RCTs) evaluating the effectiveness of ESWT versus control treatment in the management of midportion Achilles tendinopathy.

Following a comprehensive search of the literature, a total of 283 articles were identified. Following the screening of titles and abstracts, 236 articles were excluded. The main reasons for exclusion were the identification of duplicates, non-randomised studies, and the use of ESWT on other pathology. Following the exclusion of 236 articles, 47 articles were retrieved for full-text review. Of these 47 articles, 40 were excluded leaving a total of 7 RCTs eligible for inclusion in this review. There was consistent evidence from 4 RCTs that ESWT is effective in the management of midportion Achilles tendinopathy.

This review suggests that ESWT is a safe and effective modality for treating midportion Achilles tendinopathy as it reduces pain and improves function. The best available evidence suggests that a combination of ESWT with eccentric exercises and stretching may be even more effective than ESWT alone. Further research is required to confirm this and to determine the optimum ESWT treatment protocol.

Update on Fibrocartilaginous Disease Clinical Examination

This article provides an update on fibrocartilaginous disease clinical examination. Lesser metatarsophalangeal joint instability is a challenging entity for the foot and ankle surgeon. A correct diagnosis is crucial to instill an appropriate treatment plan that will result in a successful outcome and a satisfied patient. Insertional Achilles tendon disorders are common among active and inactive patients. There is also a high predilection for Achilles tendon pathology among athletes. In this article demographics and patient history, causative factors, differential diagnosis, physical examination, clinical tests, and radiographic evaluation are discussed for plantar plate disorders and insertional Achilles disorders.

Neuromechanical changes in Achilles tendinopathy and the effects of exercise-induced mechanical tendon loading: a protocol for a systematic review

INTRODUCTION

Achilles tendinopathy (AT) is a debilitating overuse injury characterised by pain, impaired functional performance, morpho-mechanical changes to the Achilles tendon and triceps surae neuromuscular alterations. Loading-based exercise has become the principal non-surgical choice for the treatment of AT; however, mechanistic evidence by which loading-based treatment may help to resolve tendon pain remains unclear. This systematic review aims to summarise the evidence of the neuromechanical changes produced by AT and by exercise-induced mechanical loading.

METHODS AND ANALYSIS

This systematic review protocol was informed and reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA-P) and the Cochrane Handbook for Systematic Reviews of Interventions. Pubmed, MEDLINE, EMBASE, CINAHL Plus, Web of Science and SPORTDiscus electronic databases will be searched from inception to February 2021. Additionally, grey literature and key journals will be reviewed. Risk of bias will be determined independently by two reviewers using the version 2 of the Cochrane risk-of-bias tool for randomised trials (RoB 2) and the risk of bias in non-randomised studies - of interventions (ROBINS-I) tool according to Cochrane recommendations. Quality of the cumulative evidence will be assessed with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) guidelines. If homogeneity exists between groups of studies, a random-effects meta-analysis will be conducted. If not, results will be synthesised narratively.

ETHICS AND DISSEMINATION

Our findings will be disseminated through publication in a peer-reviewed journal and presented at conferences. No ethical approval was required.

PROSPERO REGISTRATION NUMBER

CRD42021231933.

Low Molecular Weight Hyaluronic Acid (500-730 Kda) Injections in Tendinopathies-A Narrative Review

Tendinopathies are common causes of pain and disability in general population and athletes. Conservative treatment is largely preferred, and eccentric exercise or other modalities of therapeutic exercises are recommended. However, this approach requests several weeks of consecutive treatment and could be discouraging. In the last years, injections of different formulations were evaluated to accelerate functional recovery in combination with usual therapy. Hyaluronic acid (HA) preparations were proposed, in particular LMW-HA (500-730 kDa) for its unique molecular characteristics in favored extracellular matrix homeostasis and tenocyte viability. The purpose of our review is to evaluate the state-of-the-art about the role of 500-730 kDa in tendinopathies considering both preclinical and clinical findings and encourage further research on this emerging topic.

Tendon midsubstance trauma as a means for the development of translatable chronic rotator cuff degeneration in an ovine model

BACKGROUND

Chronic degeneration of rotator cuff tendons is a major contributing factor to the unacceptably high prevalence of rotator cuff repair surgery failures. The etiology of chronic rotator cuff degeneration is not well understood, and current therapies are not effective, necessitating preclinical research to fill this knowledge gap. Unfortunately, current large animal models rely on enthesis disruption as a means of model generation, which is not representative of human patients with chronic rotator cuff degeneration prior to full-thickness tears. Following, the goal of this study was to develop and characterize a translational large-animal model of chronic rotator cuff degeneration without enthesis release.

METHODS

A midsubstance damage model [i.e., "combed fenestration" (CF)] in adult sheep was generated by creating 16 longitudinal cuts within the top third of the infraspinatus tendon thickness. Tendon integrity was characterized through exhaustive non-destructive biomechanical stress relaxation testing [peak stress, peak load, percent relaxation, and cross-sectional area (CSA)], followed by histopathological degeneration scoring and analysis (Bonar score), histomorphological analysis of collagen organization and fatty atrophy (percent adipose area), and gene expression analyses.

RESULTS

The CF model tendons exhibited significantly decreased mechanical properties as evidenced by decreased peak stress (P<0.025) and increased percent relaxation (18-week vs. Control, P<0.035) at multiple strain magnitudes and across all timepoints. At all timepoints, the CF tendons exhibited pathological changes aligned with tendon degeneration, as evidenced by increased Bonar scoring (P<0.001) and decreased collagen organization (6-week vs. Control, P=0.013). Increases in intramuscular adipose content were also documented through histomorphology analysis (6- and 18-week vs. Control, P<0.077). Significant changes in gene expression were noted at all timepoints.

CONCLUSIONS

These data reveal that this new ovine CF model of chronic rotator cuff degeneration results in tendons with decreased mechanical properties, degenerative pathology characteristics, and gene expression profiles that aligned with the degenerative changes that have been noted in humans with tendinopathy. For these reasons, we believe this novel large animal model of chronic rotator cuff degeneration is a translational platform in which to test devices, therapies, and/or technologies aimed at repairing damage to the shoulder.

The clinical diagnosis of Achilles tendinopathy: a scoping review

Background

Achilles tendinopathy describes the clinical presentation of pain localised to the Achilles tendon and associated loss of function with tendon loading activities. However, clinicians display differing approaches to the diagnosis of Achilles tendinopathy due to inconsistency in the clinical terminology, an evolving understanding of the pathophysiology, and the lack of consensus on clinical tests which could be considered the gold standard for diagnosing Achilles tendinopathy. The primary aim of this scoping review is to provide a method for clinically diagnosing Achilles tendinopathy that aligns with the nine core health domains.

Methodology

A scoping review was conducted to synthesise available evidence on the clinical diagnosis and clinical outcome measures of Achilles tendinopathy. Extracted data included author, year of publication, participant characteristics, methods for diagnosing Achilles tendinopathy and outcome measures.

Results

A total of 159 articles were included in this scoping review. The most commonly used subjective measure was self-reported location of pain, while additional measures included pain with tendon loading activity, duration of symptoms and tendon stiffness. The most commonly identified objective clinical test for Achilles tendinopathy was tendon palpation (including pain on palpation, localised tendon thickening or localised swelling). Further objective tests used to assess Achilles tendinopathy included tendon pain during loading activities (single-leg heel raises and hopping) and the Royal London Hospital Test and the Painful Arc Sign. The VISA-A questionnaire as the most commonly used outcome measure to monitor Achilles tendinopathy. However, psychological factors (PES, TKS and PCS) and overall quality of life (SF-12, SF-36 and EQ-5D-5L) were less frequently measured.

Conclusions

There is significant variation in the methodology and outcome measures used to diagnose Achilles tendinopathy. A method for diagnosing Achilles tendinopathy is proposed, that includes both results from the scoping review and recent recommendations for reporting results in tendinopathy.

Mechanobiology in Tendon, Ligament, and Skeletal Muscle Tissue Engineering

Tendon, ligament, and skeletal muscle are highly organized tissues that largely rely on a hierarchical collagenous matrix to withstand high tensile loads experienced in activities of daily life. This critical biomechanical role predisposes these tissues to injury, and current treatments fail to recapitulate the biomechanical function of native tissue. This has prompted researchers to pursue engineering functional tissue replacements, or dysfunction/disease/development models, by emulating in vivo stimuli within in vitro tissue engineering platforms-specifically mechanical stimulation, as well as active contraction in skeletal muscle. Mechanical loading is critical for matrix production and organization in the development, maturation, and maintenance of native tendon, ligament, and skeletal muscle, as well as their interfaces. Tissue engineers seek to harness these mechanobiological benefits using bioreactors to apply both static and dynamic mechanical stimulation to tissue constructs, and induce active contraction in engineered skeletal muscle. The vast majority of engineering approaches in these tissues are scaffold-based, providing interim structure and support to engineered constructs, and sufficient integrity to withstand mechanical loading. Alternatively, some recent studies have employed developmentally inspired scaffold-free techniques, relying on cellular self-assembly and matrix production to form tissue constructs. Whether utilizing a scaffold or not, incorporation of mechanobiological stimuli has been shown to improve the composition, structure, and biomechanical function of engineered tendon, ligament, and skeletal muscle. Together, these findings highlight the importance of mechanobiology and suggest how it can be leveraged to engineer these tissues and their interfaces, and to create functional multitissue constructs.

Unprecedented Improvement of Near-Infrared Photothermal Conversion Efficiency to 87.2% by Ultrafast Non-radiative Decay of Excited States of Self-Assembly Cocrystal

Near-infrared (NIR) photothermal conversion is of great interest in many fields. Here, a self-assembly organic cocrystal (N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) and pyromellitic dianhydride (PMDA)) with strong absorption in NIR range is constructed, with widespread absorption (200-1500 nm) and very high NIR photothermal conversion efficiency (87.2%). Essentially, in this cocrystal, a small HOMO-LUMO gap of donor-acceptor pair boosts the absorption ability of this cocrystal in the NIR range. The mixed stacking structure significantly enhances the intermolecular interactions as well as the electron-hole delocalization, suppressing the emission processes, leading to nonradiative decay processes from excited states. Strong intermolecular interactions enable the cocrystal to have dense electronic energy levels, leading to a high proportion (94.4%) vibrational cooling and internal conversion processes with ultrafast excited-state relaxation (0.12 ps), which contributes to high NIR photothermal conversion efficiency. Furthermore, the cocrystal has exhibited capable ability for being an excellent candidate for a NIR photothermal therapy agent.

Functional Outcomes of Insertional Achilles Tendinopathy Treatment: A Systematic Review

BACKGROUND

Achilles tendinopathy is a common clinical problem that can be either insertional or noninsertional, and effective treatment of each type can vary. We sought to investigate the current evidence on different treatment methods for insertional Achilles tendinopathy with a focus on functional outcomes.

METHODS

We performed a systematic review of the available literature using the PubMed/MEDLINE and Cochrane Central Register of Controlled Trials databases. Data from included studies were categorized according to treatment method and reported with respect to functional outcomes and complications.

RESULTS

A total of 1,457 abstracts were reviewed; 54 studies with 2,177 patients met the inclusion criteria. Among the 54 studies, 6 operative techniques and 6 nonoperative treatments were evaluated.

CONCLUSIONS

Eccentric exercises and low-energy extracorporeal shockwave therapy (ESWT) have the greatest evidence for the initial management of insertional Achilles tendinopathy. ESWT has been increasingly studied in recent years, but more high-quality evidence is needed. Operative treatment with tenotomy, debridement, retrocalcaneal bursectomy, and calcaneal exostectomy is effective. Flexor hallucis longus tendon transfer may benefit cases of more severe disease. Minimally invasive procedures have a potential role in the treatment algorithm and require more rigorous study.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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.

Complete mid-portion rupture of the rat achilles tendon leads to remote and time-mismatched changes in uninjured regions

PURPOSE

To examine healing adaptations over 17 weeks post Achilles tendon (AT) rupture in the injured region (IR) compared to an uninjured region (UIR) of the AT.

METHODS

Twenty-four rats were subjected to a complete right-sided AT rupture, while the left side served as a control. ATs were harvested at 1, 2, 8 and 17 weeks post-rupture and stained with antibodies specific to Collagen type I (Col I) and II (Col II) as well as Alcian Blue and Picrosirius Red staining techniques. Histopathological changes, proteoglycan content, collagen alignment and immunoexpression were assessed.

RESULTS

Both regions examined, IR and UIR, exhibited over weeks 1-17 similar healing adaptations of increasing collagen alignment, decreasing Col I immunoexpression, as well as increasing proteoglycan content and Col II occurrence. Increased proteoglycan content was found already at week 2 in the UIR, while it first increased at week 8 in the IR. The area positive to Col II was increased compared to controls at week 8 in the UIR, whereas it first raised at week 17 in the IR. Collagen disorganization successively declined to reach control levels at week 17 in the UIR, but was still higher in the IR.

CONCLUSION

This study demonstrated that uninjured areas of the AT remote from the rupture site also undergo pronounced remodeling, although with time-span differences relative to injured AT portions. These changes including the pathologic heterotopic mineralization and chondrogenic differentiation observed in both regions may have implications in the choice of rehabilitation regimes in order to prevent secondary rupture.

Short- and Intermediate-Term Results of Extracorporeal Shockwave Therapy for Noninsertional Achilles Tendinopathy

BACKGROUND

Earlier randomized controlled trials (RCTs) reported only midterm (3-4 months) results of extracorporeal shockwave therapy (ESWT) as a treatment for noninsertional Achilles tendinopathy (NAT). This study compared the effectiveness of an eccentric loading program followed by stretching exercises combined with ESWT (study group) or sham ESWT (control group) for treating chronic NAT in both the short and long term.

METHODS

This double-blind RCT was conducted between 2018 and 2020. Adult patients with unilateral NAT who failed standard conservative treatment were randomly allocated to either group. Function and pain were assessed at baseline, 1 month, and 16 months using the Victorian Institute of Sport Assessment-Achilles questionnaire (VISA-A) and visual analog scale (VAS), respectively. Mixed-design analysis of variance and nonparametric statistics were performed. Twenty-two men and 28 women aged 18 to 40 years were allocated into 2 equally matched groups.

RESULTS

Function and pain scores in the study group were not significantly different from control group scores at baseline (VISA-A: 22.2 ± 6.5 vs 21.0 ± 5.2 and VAS: 8 ± 1 vs 8 ± 1, respectively). Both groups significantly improved posttreatment (VISA-A: 85 ± 6.2 vs 53.4 ± 7.7 and VAS: 1 ± 2 vs 7 ± 2, respectively). At the 16-month follow-up, outcome scores declined slightly but significantly in the study group (VISA-A: 80 ± 5.3; VAS: 3 ± 2) and improved in the control group (VISA-A: 67 ± 5.6; VAS: 5 ± 1). However, both groups were significantly better than baseline. At both time points, the study group had significantly superior scores (statistically and clinically) than the control group (P = .0001).

CONCLUSION

Combining calf eccentric loading with stretching exercises resulted in significant improvements in the pain and functional scores in patients with NAT. Adding ESWT to this combined protocol resulted in significantly greater improvements in both the short and long term.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Mini-Invasive, Ultrasound Guided Repair of the Achilles Tendon Rupture-A Pilot Study

Percutaneous acute Achilles tendon rupture suturing has become a leading treatment option in recent years. A common complication after this mini-invasive procedure is sural nerve injury, which can reduce the patients’ satisfaction and final outcomes. High-resolution ultrasound is a reliable method for localizing the sural nerve, and it can be performed intra-operatively; however, the long-term results are yet unknown. The aim of the study was to retrospectively evaluate the long-term results of percutaneous Achilles tendon repair supported with real-time ultrasound imaging. We conducted 57 percutaneous sutures of acute Achilles tendon rupture between 2005 and 2015; 30 were sutured under sonographic guidance, while 27 were performed without sonographic assistance. The inclusion criteria were acute (less than 7 days) full tendon rupture, treatment with the percutaneous technique, age between 18 and 65 years, and a body mass index (BMI) below 35. The operative procedure was carried out by two surgeons, according to the surgical technique reported by Maffulli et al. In total, 35 patients were available for this retrospective assessment; 20 (16 men and 4 women) were treated with sonographic guidance, while 15 (12 men and 3 women) underwent the procedure without it. The mean follow-up was 8 years (range, 3–13 years). The sural nerve was localized 10 mm to 20 mm (mean, 15.8; SD, 3.02) laterally from the scar of the Achilles tendon tear. There was no significant difference between groups with respect to the FAOQ score (P < 0.05). High-resolution ultrasounds performed intra-operatively can minimize the risk of sural nerve injury during percutaneous Achilles tendon repair.

Astrocyte reactivity in spinal cord and functional impairment after tendon injury in rats

Astrocyte reactivity in the spinal cord may occur after peripheral neural damage. However, there is no data to report such reactivity after Achilles tendon injury. We investigate whether changes occur in the spinal cord, mechanical sensitivity and gait in two phases of repair after Achilles tendon injury. Wistar rats were divided into groups: control (CTRL, without rupture), 2 days post-injury (RUP2) and 21 days post-injury (RUP21). Functional and mechanical sensitivity tests were performed at 2 and 21 days post-injury (dpi). The spinal cords were processed, cryosectioned and activated astrocytes were immunostained by GFAP at 21 dpi. Astrocyte reactivity was observed in the L5 segment of the spinal cord with predominance in the white matter regions and decrease in the mechanical threshold of the ipsilateral paw only in RUP2. However, there was gait impairment in both RUP2 and RUP21. We conclude that during the acute phase of Achilles tendon repairment, there was astrocyte reactivity in the spinal cord and impairment of mechanical sensitivity and gait, whereas in the chronic phase only gait remains compromised.

Enthesis trauma as a means for the development of translatable chronic rotator cuff degeneration in an ovine model

BACKGROUND

Untreated rotator cuff tears lead to irreversible tendon degeneration, resulting in unacceptable repair prognosis. The inability of current animal models of degenerated rotator cuff tendons to more fully emulate the manifestation and degree of pathology seen in humans with a previously torn rotator cuff tendon (s) significantly impairs the development of novel therapeutics. Therefore, the objective of this study was to develop a large-animal translational model of enthesis damage to the rotator cuff tendons to mimic the chronic degenerative changes that occur in patients that demonstrate clinical manifestations of tendinopathy.

METHODS

A partial enthesis tear model (i.e., sharp transection) in adult sheep was created by cutting the tendon fibers perpendicularly through the enthesis midpoint, while leaving the other portion of the tendon in-tact. To assess tendon integrity, non-destructive biomechanical tests were performed, followed by histopathological, histomorphological, and gene expression analysis. Samples of degenerated human rotator cuff tendons obtained from patients undergoing reverse total shoulder arthroplasty to use for comparative pathological analysis.

RESULTS

In the sheep model, transected tendons at all timepoints had significantly decreased mechanical properties. Histopathologic evaluation and Bonar scoring revealed that the tendons in sheep underwent degenerative changes similar in magnitude and manifestation as the degenerated human tendon samples. Furthermore, similar levels of collagen disorganization were noted between the 6 and 12-week ovine samples and the degenerated human samples.

CONCLUSIONS

These findings indicate that the new sheep model of rotator cuff injury reliably recapitulates the structural and cellular changes that occur clinically in humans with chronic rotator cuff tendon injuries and suggest that this new model is well suited to evaluation of new therapeutic interventions.

Treatment of Achilles Tendinopathy in Recreational Runners with Peritendinous Hyaluronic Acid Injections: A Viscoelastometric, Functional, and Biochemical Pilot Study

BACKGROUND

Achilles tendinopathy (AT) affects ca. 10 million recreational runners in Europe; the practice of hyaluronic acid (HA) infiltration is being increasingly adopted. The aim of this pilot study was to monitor the effects of a three-local time-spaced injections regimen of HA in the treatment of AT in middle-aged runners combining for the first time viscoelastometric, biochemical, and functional methodologies with routine clinical examinations.

METHODS

Eight male runners (Age 49.3 ± 3.9), diagnosed for unilateral AT, were given three ultrasound (US) guided peritendinous HA injections at the baseline (T0) and every fifteenth day with a follow-up on the forty-fifth day (T1, T2, and T3). At all-time points patients were assessed for viscoelastic tone and stiffness, maximal voluntary isometric contraction (MVIC), and pain level (Likert scale 0-5). The peritendinous effusions of the injured tendon were collected at T0 and T2 to quantify the volume variations and the IL-1β and MMP-3 levels.

RESULTS

At T0 MVIC and pain score were significantly lower and higher, respectively, in injured tendons. The volume, IL-1β and MMP-3 levels decreased in the course of treatment and the clinical endpoints ameliorated over time. Tone, stiffness, and functional performance also varied significantly at T2 and T3, as compared to T0.

CONCLUSIONS

The sequential peritendinous injections of HA were effective in the amelioration of the clinical symptoms, as well as of the functional and viscoelastic state associated with AT. The determination of the viscoelastometric state may help to precisely evaluate the healing process in AT patients.

Telehealth sounds a bit challenging, but it has potential: participant and physiotherapist experiences of gym-based exercise intervention for Achilles tendinopathy monitored via telehealth

Background

Although telehealth is becoming more popular for delivery of care for individuals with musculoskeletal pain, to our knowledge telehealth has not been used to manage Achilles tendinopathy. This research aimed to explore the experience of participants and physiotherapists with gym-based exercise interventions for Achilles tendinopathy monitored via videoconference.

Methods

A qualitative, interpretive description design was performed using semi-structured interviews (8 participants) and a focus group (7 physiotherapists). Participants and physiotherapists were interviewed about their experiences of the use of telehealth during a gym-based exercise intervention incorporating different calf load parameters for Achilles tendinopathy. We employed an inductive thematic analysis approach to analyse the data.

Results

Three themes identified from both participants and physiotherapists included i) acceptability of telehealth; ii) enablers to adherence with telehealth; and iii) barriers to adherence with telehealth. Two extra themes arose from participants regarding adherence with gym-based exercise, including enablers to adherence with the exercise intervention, and barriers to adherence with the exercise intervention. Both participants and physiotherapists expressed overall satisfaction and acceptability of telehealth monitoring of gym-based exercise.

Conclusion

Gym-based exercise intervention for Achilles tendinopathy involving weekly telehealth monitoring was acceptable to both participants and physiotherapists. Potential enablers and barriers were identified that may improve adherence to this type of intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03907-w.

Plasmonically Modulated Gold Nanostructures for Photothermal Ablation of Bacteria

With the wide utilization of antibiotics, antibiotic-resistant bacteria have been often developed more frequently to cause potential global catastrophic consequences. Emerging photothermal ablation has been attracting extensive research interest for quick/effective eradication of pathogenic bacteria from contaminated surroundings and infected body. In this field, anisotropic gold nanostructures with tunable size/morphologies have been demonstrated to exhibit their outstanding photothermal performance through strong plasmonic absorption of near-infrared (NIR) light, efficient light to heat conversion, and easy surface modification for targeting bacteria. To this end, this review first introduces thermal treatment of infectious diseases followed by photothermal therapy via heat generation on NIR-absorbing gold nanostructures. Then, the usual synthesis and spectral features of diversified gold nanostructures and composites are systematically overviewed with the emphasis on the importance of size, shape, and composition to achieve strong plasmonic absorption in NIR region. Further, the innovated photothermal applications of gold nanostructures are comprehensively demonstrated to combat against bacterial infections, and some constructive suggestions are also discussed to improve photothermal technologies for practical applications.

Correlation Between Gastrocnemius Tightness and Heel Pain Severity in Plantar Fasciitis

BACKGROUND

It is known that there is an association between gastrocnemius tightness and plantar fasciitis, but this has never been quantified. The purpose of the study was to determine the correlation between gastrocnemius tightness and the severity of heel pain in plantar fasciitis.

METHODS

Thirty-three patients were prescribed physiotherapist-directed gastrocnemius stretching exercises, a Strassburg Sock or night splint, and silicone heel insoles as required. Outcome measures included (1) gastrocnemius tightness, (2) 100-mm visual analog scale (VAS) for pain on the first steps in the morning, and (3) 100-mm VAS for the worst pain felt during the previous week. Gastrocnemius tightness was measured by the difference in maximal ankle dorsiflexion between knee bent and straight with a goniometer.

RESULTS

The mean gastrocnemius tightness was 22 degrees at baseline compared with 9 degrees at the final follow-up (P < .01). A reduction in VAS for pain on the first steps in the morning and VAS for the worst pain felt during the previous week from baseline to final follow-up was observed (P < .01). Correlation analysis of 105 data points between gastrocnemius tightness and VAS for pain on the first steps in the morning was R = 0.757 (P < .001), and between gastrocnemius tightness and VAS for the worst pain felt during the previous week was R = 0.781 (P < .001).

CONCLUSION

The study observed a strong, statistically significant correlation between gastrocnemius tightness and the severity of heel pain in plantar fasciitis.

LEVEL OF EVIDENCE

Level IV, case series.

[Research progress in Achilles tendinopathy]

Objective

To explore the classification, diagnosis, and clinical treatment of Achilles tendinopathy.

Methods

The literature about Achilles tendinopathy at home and abroad was reviewed. The research results of classification and terms, imaging diagnosis, and clinical treatment of Achilles tendinopathy were summarized.

Results

The classification and name of Achilles tendinopathy are not completely unified, and the concept is vague, the cause of disease is not clear. There are many treatment plans, but there is no effective evidence-based medicine research.

Conclusion

The diagnosis and treatment of Achilles tendinopathy is complicated. According to the characteristics of Achilles tendon anatomy and etiology, the classification and definition of Achilles tendinopathy need to be further studied in order to guide clinical treatment more effectively and facilitate experience exchange and learning.

Management of Achilles and patellar tendinopathy: what we know, what we can do

Tendinopathies are challenging conditions frequent in athletes and in middle-aged overweight patients with no history of increased physical activity. The term “tendinopathy” refers to a clinical condition characterised by pain, swelling, and functional limitations of tendons and nearby structures, the effect of chronic failure of healing response. Tendinopathies give rise to significant morbidity, and, at present, only limited scientifically proven management modalities exist. Achilles and patellar tendons are among the most vulnerable tendons, and among the most frequent lower extremity overuse injuries. Achilles and patellar tendinopathies can be managed primarily conservatively, obtaining good results and clinical outcomes, but, when this approach fails, surgery should be considered. Several surgical procedures have been described for both conditions, and, if performed well, they lead to a relatively high rate of success with few complications. The purpose of this narrative review is to critically examine the recent available scientific literature to provide evidence-based opinions on these two common and troublesome conditions.

Regional differences in turnover, composition, and mechanics of the porcine flexor tendon

PURPOSE

Recent data suggest that there is a lack of turnover in the core of human tendon, but it remains unknown whether there are regional differences between core and periphery of the cross section. The purpose of this project was to investigate regional differences in turnover as estimated by the accumulation of fluorescent Advanced Glycation End-products (AGEs) and regional differences in mechanical properties.

MATERIALS AND METHODS

Tendons were obtained from lean control (n = 4) and diabetic Göttingen minipigs (streptozotocin-induced, n = 6). The deep digital flexor tendon of one hind limb was separated into a proximal, central and distal part. Autofluorescence was measured in the core and periphery of the proximal and distal parts of the tendon, and mechanical properties were tested on fascicles taken from the core and periphery of the central tendon (only diabetic animals).

RESULTS

Autofluorescence was greater in the proximal than the distal part. In the distal part of the lean control animals, autofluorescent AGE accumulation was also greater in the core than the periphery. Peak modulus in the core region (704 ± 79 MPa) was higher than the periphery (466 ± 53 MPa, p < 0.05) in diabetic tendons.

CONCLUSION

Taken together, autofluorescence varied both along the length and across the tendon cross section, indicating higher turnover in the distal and peripheral regions. In addition, mechanical properties differed across the tendon cross-section.

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.

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

OBJECTIVE

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

DATA SOURCES

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

MAIN RESULTS

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

CONCLUSIONS

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

Achilles Tendon Lesions - Part 1: Tendinopathies

Calcaneal tendon injuries are extremely common in the general population and in orthopedics routine care. Its increasing incidence, which is motivated by an aging population, improved access to the health care system, increased prescription of continuous-use medication, erratic participation in sports and other factors, has had a direct impact on society. Consolidated treatment options for tendinopathies lack quality scientific support for many modalities. New therapies have emerged to enhance nonsurgical approach outcomes and to reduce the number of patients requiring surgery. Although these operative procedures provide good pain relief and functional outcomes, they are costly and may lead to complications.

Achilles tendinopathy

BACKGROUND

Achilles Tendinopathy (AT) is essentially a failed healing response with haphazard proliferation of tenocytes, abnormalities in tenocytes with disruption of collagen fibers, and subsequent increase in non-collagenous matrix.

METHODS

The diagnosis of Achilles tendinopathy is clinical, and MRI and utrasound imaging can be useful in differential diagnosis. Conservative manegement, open surgery or minimally invasive techniques are available. Injections and physical therapy are also vauable options.

RESULTS

Eccentric exercises are useful tools to manage the pathology. If the condition does not ameliorate, shock wave therapy, or nitric oxide patches might be considered. Peritendinous injections or injections at the interface between the Achilles tendon and Kager's triangle could be considered if physical therapy should fail. Surgery is indicated after 6 months of non-operative management.

CONCLUSIONS

The clinical diagnosis and management of AT are not straightforward. Hence, patients should understand that symptoms may recur with either conservative or surgical approaches.

Badminton Injuries in Elite Athletes: A Review of Epidemiology and Biomechanics

Badminton is a popular sport in India and with multiple medal prospects will be closely followed at the Tokyo 2020 Olympics. Considered the fastest of the racquet sports, players require aerobic stamina, agility, strength, speed, and precision, besides requiring good motor coordination and complex racquet movements. Injuries in badminton are common despite it not being a contact sport, and include overuse injuries, and acute traumatic events. The game is physically challenging and demands complex repetitive upper and lower extremity movements with constant postural variations and poses a high risk of overuse injuries to both the appendicular and axial musculoskeletal systems. Badminton also necessitates short bursts of movement with sudden sharp changes in direction, which places players at risk of non-contact traumatic injuries to joints and muscle-tendon units. Preventing injuries and decreasing time away from training and competition are critical in an elite badminton player's sporting career. This analytical review identifies the incidence, severity, and profile of badminton injuries in elite players, and discusses the biomechanical basis of these injuries.

The association of working alliance, outcome expectation, adherence and self-efficacy with clinical outcomes for Achilles tendinopathy: A feasibility cohort study (the MAP study)

INTRODUCTION

This study evaluated the feasibility of a large longitudinal cohort study utilizing an online platform to investigate the association and predictive relationship of working alliance, outcome expectations, adherence and self-efficacy with outcome in Achilles tendinopathy. The objectives were: (1) to determine the recruitment and retention rate and (2) to carry out preliminary data analysis of the selected variables and clinical outcomes.

METHODS

A multi-centred, longitudinal feasibility cohort study was used. Eligible participants were directed to a bespoke online platform hosting study information and the outcome measures in the form of an online questionnaire. Responses from the online questionnaire were collected on three occasions: at baseline, at 6 and at 12 weeks following completion of the first questionnaire. Feasibility outcomes (recruitment and retention rates) were described using descriptive statistics.

RESULTS

The website recorded a total 55 views. These 55 views resulted in 24 participants consenting to join the study. The questionnaire at baseline was started 63 times and completed on 60 separate occasions resulting in a 95% conversion rate. Retainment for completion of the questionnaire for a second time was 83.3% and for the third time was 66.6%. All questionnaires were completed fully yielding a missing data indicator of 0%.

CONCLUSIONS

Feasibility studies ask the question 'can this be done'? Based on the data from recruitment and rates and exploratory correlation analysis a future study can be done; this previously untested online platform appears feasible, but changes could be useful before proceeding to a much larger study.

The efficacy of loading programmes for improving patient-reported outcomes in chronic midportion Achilles tendinopathy: A systematic review

OBJECTIVE

Achilles tendinopathy is a common type of overuse condition, with isolated eccentric loading (ECL) programmes being the principal conservative treatment of choice. However, alternative protocols, involving different contraction types, have more recently been investigated. The purpose of the present review was to examine the evidence from studies comparing two or more different types of loading programmes in relation to patient-reported outcomes for people with Achilles tendinopathy.

METHODS

A systematic review was undertaken, and the risk of bias of included papers were assessed using the Cochrane Risk of Bias tool. An electronic search of CINAHL, MEDLINE, Embase and SPORTDiscus was undertaken from their inception to May 2018. The eligibility criteria for selecting studies were randomized controlled or clinical controlled trials investigating two or more different loading programmes for chronic (>3 months) Achilles tendinopathy.

RESULTS

Seven articles were included in the review. Low-quality evidence exists that a do-as-tolerated modification of the Alfredson programme is more effective than the standardized programme at improving function in the short term. Very-low-quality evidence suggests that ECL is superior at reducing pain levels than concentric in isolation, but no more effective at improving pain or disability than concentric-eccentric programmes.

CONCLUSIONS

There is conflicting evidence regarding the superiority of ECL over other contraction types, challenging the current approach to managing Achilles tendinopathy. There is also evidence that do-as-tolerated repetition volumes are more effective at improving function in the short term compared with those recommended by the standardized Alfredson protocol.

A Mathematical Model of Achilles Tendon Overload During Jump Shot

Introduction

Achilles tendon injuries usually occur with abrupt movements at the level of the ankle and foot, and the consequence is the overload of the Achilles tendon.

Aim

Examine the Achilles tendon load as a function of the landing angle, and find the critical point at which the tendon overload begins and when a further increase in the landing angle can lead to rupture.

Methods

The study has a prospective character. The input data represent the anthropometric values of the respondents, who are professional basketball players in the senior national team of Bosnia and Herzegovina and were processed in the CATIA v5-6 software solution. Software data processing analyzed the landing angles and the transfer of force to the Achilles tendon. The end result is a regression curve, which projects the angle at which the Achilles tendon is overloaded, and indicates an increased risk of possible injury to the tendon itself.

Results

The onset of overloading starts at an angle of 32.28° and at an angle of 35.75° the overloaded load occurs, indicating the need for the subject to change the position of the foot to prevent damage to the tendon itself.

Conclusion

An angle of 35.75° is the critical point at which the Achilles tendons are overloaded at the very landing. Prevention of injury should go in the direction of practicing the feet for a particular position at the time of the landing, and in the direction to develop adequate footwear that would mitigate the angle at the landing.

Inhibition of CD44 induces apoptosis, inflammation, and matrix metalloproteinase expression in tendinopathy

Apoptosis has emerged as a primary cause of tendinopathy. CD44 signaling pathways exert anti-apoptotic and -inflammatory effects on tumor cells, chondrocytes, and fibroblast-like synoviocytes. The aim of this study was to examine the association among CD44, apoptosis, and inflammation in tendinopathy. Expression of CD44 and apoptotic cell numbers in tendon tissue from patients with long head of biceps (LHB) tendinopathy were determined according to the histological grades of tendinopathy. Primary tenocytes from Achilles tendon of Sprague-Dawley rats 1 week after collagenase injection were cultured with an antagonizing antibody against CD44. Treatment responses were determined by evaluating cell viability and expression of tendon-related proliferation markers, inflammatory mediators, and apoptosis. The expression of CD44 and apoptosis were positively correlated with the severity of tendinopathy in the human LHB tendinopathy. Furthermore, CD44 expression and apoptotic cells were co-stained in tendinopathic tendon. Blocking the CD44 signaling pathways in rat primary tenocytes by OX-50 induced cell apoptosis and the elevated levels of cleaved caspase-3. Furthermore, they had decreased cell viability and expression of collagen type I, type III, tenomodulin, and phosphorylated AKT. In contrast, there were elevated levels of inflammatory mediators, including interleukin (IL)-1β, IL-6, tumor necrosis factor-α, cyclooxygenase-2, and phosphorylated NF-κB, as well as matrix metalloproteinase (MMP) family members including MMP-1, -3, -9, and -13 in tenocytes upon OX-50 treatment. This study is the first to demonstrate the association of CD44 and apoptosis in tendinopathy. Our data imply that CD44 may play a role in tendinopathy via regulating apoptosis, inflammation, and extracellular matrix homeostasis.

Characterisation of Achilles tendon pain in recreational runners using multidimensional pain scales

OBJECTIVES

The main assessment tool for Achilles tendinopathy (AT) is the VISA-A. However, the VISA-A only assesses the physical impairments that result from tendon pain. This study sought to describe and assess tendon pain using other multidimensional pain scales; the short forms of the McGill pain questionnaire (sf-MPQ) and the Brief Pain Inventory (sf-BPI).

DESIGN

Cross sectional observational study.

METHODS

124 recreational runners with clinically confirmed mid-portion Achilles tendinopathy for at least 3 months were recruited from Cape Town, South Africa. They described and rated their tendinopathy symptoms by completing the VISA-A, sf-BPI and sf-MPQ questionnaires.

RESULTS

Tendon pain was largely described as a sensory type of pain with minimal affective elements. Sixty percent described their pain as aching. Significant proportions described it as tender (52.9%), throbbing (33.9%), hot burning (24.8%) and 33.8% ranked it as discomfiting or worse on the pain intensity score of the sf-MPQ. Tendon pain interfered with mood in 50.8% of the participants as well as with walking ability (72.5%), sleep (34.8%) and enjoyment of life (54.2%).

CONCLUSIONS

Tendon pain was described using a variety of adjectives which may suggest that AT has clinical subtypes. Tendon pain interferes with more than just physical function. Therefore, the recommendation is to conduct further studies using various pain questionnaires to elicit more details and better understand the nature of Achilles tendon pain.