Achilles tendinopathy

Collagen denaturation in post-run Achilles tendons and Achilles tendinopathy: In vivo mechanophysiology and magnetic resonance imaging

Achilles tendinopathy is often attributed to overuse, but its pathophysiology remains poorly understood. Disruption to the molecular structure of collagen is fundamental for the onset and progression of tendinopathy but has mostly been investigated in vitro. Here, we interrogated the in vivo molecular structure changes of collagen in rat Achilles tendons following treadmill running. Unexpectedly, the tendons' collagen molecules were not mechanically unfolded by running but denatured through proteolysis during physiological post-run remodeling. We further revealed that running induces inflammatory gene expressions in Achilles tendons and that long-term running causes prolonged, elevated collagen degradation, leading to the accumulation of denatured collagen and tendinopathy development. For applications, we demonstrated magnetic resonance imaging of collagenase-induced Achilles tendon injury in vivo using a denatured collagen targeting contrast agent. Our findings may help close the knowledge gaps in the mechanobiology and pathogenesis of Achilles tendinopathy and initiate new strategies for its imaging-based diagnosis.

The future of in-field sports biomechanics: wearables plus modelling compute real-time in vivo tissue loading to prevent and repair musculoskeletal injuries

This paper explores the use of biomechanics in identifying the mechanistic causes of musculoskeletal tissue injury and degeneration. It appraises how biomechanics has been used to develop training programmes aiming to maintain or recover tissue health. Tissue health depends on the functional mechanical environment experienced by tissues during daily and rehabilitation activities. These environments are the result of the interactions between tissue motion, loading, biology, and morphology. Maintaining health of and/or repairing musculoskeletal tissues requires targeting the "ideal" in vivo tissue mechanics (i.e., loading and deformation), which may be enabled by appropriate real-time biofeedback. Recent research shows that biofeedback technologies may increase their quality and effectiveness by integrating a personalised neuromusculoskeletal modelling driven by real-time motion capture and medical imaging. Model personalisation is crucial in obtaining physically and physiologically valid predictions of tissue biomechanics. Model real-time execution is crucial and achieved by code optimisation and artificial intelligence methods. Furthermore, recent work has also shown that laboratory-based motion capture biomechanical measurements and modelling can be performed outside the laboratory with wearable sensors and artificial intelligence. The next stage is to combine these technologies into well-designed easy to use products to guide training to maintain or recover tissue health in the real-world.

Effectiveness of Kinesiotherapy in the Treatment of Achilles Tendinopathy-A Narrative Review

This narrative review of kinesiotherapy methods in the treatment of Achilles tendinopathy (AT) encompassed a diverse range of studies, including athletes and untrained people, healthy or injured, undergoing kinesiotherapy treatments. Most experimental studies (86%) reported results related to pain perception, 27% to the range of motion, and 27% to biomechanical assessment. However, the studies showed notable heterogeneity in the outcomes associated with the interventions, and, in this review of kinesiotherapy protocols for AT, a prominent observation emerged regarding their efficacy, suggesting a more favorable impact on pain and tendon stiffness management when comparing the measured parameters between the trained and untrained groups. The importance of tailoring the treatment approach based on the individual's athletic background and conditioning status is underscored. There is a need for personalized rehabilitation strategies in athletic populations. The average duration of kinesiotherapy in the treatment of tendinopathy was 15.3 weeks. This observation underscores the potential of kinesiotherapy interventions as a viable treatment option for individuals with Achilles tendon issues. These findings underscore the urgent need for further research to provide stakeholders with more comprehensive directions for future studies. The results may be helpful for doctors, physiotherapists, trainers, and researchers interested in this topic.

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.

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.

A Comparative Study of the Graston Technique and Alfredson Protocol in the Management of Achilles Tendinopathy

BACKGROUND AND OBJECTIVES

The Achilles tendon, the largest and strongest tendon in the human body, is frequently injured by overuse; this condition is known as Achilles tendinopathy (AT). It serves as a link between the heel bone and the calf muscles and is necessary for motions, such as walking, sprinting, and jumping. Evidence is presented to support the efficacy of the Graston technique and Alfredson protocol for pain reduction and improvement of function and calf muscle strength. The objective of this study is to compare the efficacy of the Graston technique versus the Alfredson protocol in patients with AT. Methods and data collection: After obtaining approval from the ethical review board of the Rawalpindi Medical University, all patients fulfilling the inclusion criteria are divided into two groups, A and B, by generating random identity numbers using Microsoft Excel for allocation. Group A comprises patients who undergo treatment with the Graston technique as conventional therapy with Alfredson protocol (12-week calf muscle eccentric exercises), while those in group B follow a Graston technique with sole heel lift. Individuals in the eccentric exercises group follow an Alfredson method-based 12-week eccentric exercise plan for their leg muscles. The workouts need to be done twice a day, seven days a week for 12 weeks. The plan includes two exercises: the first done with the knee straightened to work the gastrocnemius and the second done with the knee bent to work the soleus. Three sets of 15 repetitions with no rest interval for each exercise are completed twice a day on the affected limb to yield functional improvement.

RESULTS

The results showed that both the Alfredson protocol and the Graston technique were effective in managing AT symptoms. The study involved dividing 32 participants into two groups who received either treatment for four weeks. The main way to measure improvement was a score called the Villalta-Scanlon Achilles Tendonitis Index score. In both groups, these scores showed significant improvement (with a p-value less than 0.001, which means that the results are very statistically significant). For Group A (who received the Alfredson protocol), the average Villalta-Scanlon Achilles Tendonitis Index score before treatment was 29.25. This score increased to 31.25 at mid-treatment and 34.38 after the full four weeks of treatment. Group B (who received the Graston technique) started with an average Villalta-Scanlon Achilles Tendonitis Index score of 22.94. Their scores also increased throughout the treatment, reaching 34.94 at mid-treatment and 42.88 after four weeks. These findings provide evidence that both treatments can improve AT symptoms, with some suggestions that the Graston technique might be even more effective based on the higher average Villalta-Scanlon Achilles Tendonitis Index scores after treatment.

CONCLUSIONS

The Graston technique shows promising results, particularly in the mid- and post-treatment phases, indicating its potential efficacy in comparison to the Alfredson protocol in the treatment of AT.

Burden and Risk Factors for Achilles Tendinopathy in the Military Population, 2006-2015: A Retrospective Cohort Study

CONTEXT

Ankle-foot injuries are ubiquitous in the US military, with Achilles tendinopathy a common condition that affects function and health-related quality of life.

OBJECTIVE

To evaluate the burden and associated factors of Achilles tendinopathy.

DESIGN

Descriptive epidemiology study.

SETTING

The Defense Medical Epidemiological Database was used to identify relevant health care encounters.

PATIENTS OR OTHER PARTICIPANTS

All active duty and reserve military members who served between 2006 and 2015 (officers = 2 149 887; enlisted = 9 503 995).

MAIN OUTCOME MEASURE(S)

Multiyear prevalence of Achilles tendinopathy care episodes was calculated and compared by military rank, service branch, and year. Unadjusted and adjusted assessments of injury burden were calculated.

RESULTS

Officers incurred 37 939 episodes at a prevalence of 17.65 per 1000 servicemembers (male officers = 18.20 per 1000 servicemembers, female officers = 14.80 per 1000 servicemembers). Among enlisted personnel, 116 122 episodes of Achilles tendinopathy occurred in 12.22 per 1000 servicemembers (male enlisted = 12.07 per 1000 servicemembers, female enlisted = 13.22 per 1000 servicemembers). All officer specialties had a higher burden of Achilles tendinopathy episodes than the ground and naval gunfire officers (prevalence ratio [PR] = 1.04-1.43) except for aviation, which demonstrated a lower burden (PR = 0.65). Among enlisted occupations, maritime or naval specialties had a lower burden of Achilles tendinopathy than infantry (PR = 0.82) and all other specialties except for aviation, which had a higher burden (PR = 1.07-1.71). Multiple associated factors were identified: sex, age, rank, military occupation, and service branch.

CONCLUSIONS

Achilles tendinopathy was ubiquitous in the US military, with a progressive increase in prevalence during the study epoch. Sex, age, rank, military occupation, and service branch were identified as associated factors. These findings highlight the need for both prophylactic interventions and identification of the populations with the greatest need.

Autologous bone marrow derived mesenchymal stem cells are safe for the treatment of Achilles tendinopathy

Achilles tendinopathy is a disabling condition that affects more than 50% of runners. Pre-clinical studies in a large animal model of naturally-occurring tendinopathy similar to human Achilles tendinopathy has shown benefits of autologous bone marrow-derived mesenchymal stem cell (MSC) implantation. However, MSCs are advanced therapies medicinal products (ATMPs), with strict regulatory requirements. Guided by the regulator we carried out a first in man study to assess the safety and efficacy of autologous MSC injection in human patients with non-insertional Achilles tendinopathy. Ten patients, mean age 47 with mid-portion Achilles tendon pain and swelling for more than 6 months, underwent autologous cultured cell injections (median 12.2 × 106, range 5-19 × 106 cells) into their Achilles tendon. At 24 weeks follow-up, no serious adverse reactions or important medical events were observed. MOXFQ, EQ-5D-5L, and VISA-A scores improved clinically at 12 and 24 weeks. VAS pain improved increasingly at 6, 12 and 24 weeks. MOXFQ Pain and VISA-A Scores improved > 12 points from baseline to 24 weeks in 8 patients. Maximum anteroposterior tendon thickness as measured by greyscale US decreased by mean 0.8 mm at 24 weeks. This phase IIa study demonstrated the safety of autologous MSC injection for non-insertional Achilles tendinopathy and provides proof-of-concept of the technique in patients, all of whom had previously failed conservative treatments for chronic disease and leads the way for a larger randomised controlled trial.

Ultrasonic Evaluation of the Achilles Tendon in Patients Treated for Congenital Clubfoot: Comparison between Patients Treated with Plaster Alone, Achilles Tenotomy, and Z-Plasty Lengthening

BACKGROUND

Clubfoot is a common congenital deformity. The Ponseti technique, involving early corrective manipulations followed by applying long leg casts and Achilles tenotomy, is widely accepted as the preferred treatment. Rapid tendon healing after surgery has been documented, but the aspect regarding long-term tendon structure and properties is not known. Three cases of Achilles tendon rupture in adolescents previously treated for clubfoot have been described in the literature. As rupture is a rare event in this age group, a possible correlation with previous surgery has been hypothesized. The primary aim of the study was to compare the ultrasound findings of the Achilles tendon in patients treated for clubfoot, between patients treated with casting alone and with patients who underwent surgery (percutaneous tenotomy or Z-plasty lengthening).

METHODS

There were 22 asymptomatic patients (34 feet) with a median age of 12 years, previously treated for clubfoot, that were recruited for this study; the patients underwent an Achilles tendon ultrasound examination during a follow-up outpatient visit.

RESULTS

A greater thickness and increased number of structural alterations with the presence of hypoechoic areas of the operated tendons compared with those treated with plaster alone were observed (p-value: 0.0498 and <0.001, respectively). These ultrasound findings were indicative of tendon suffering, as seen in tendinopathies.

CONCLUSIONS

The presence of ultrasound alterations in asymptomatic patients operated on for clubfoot requires careful control of the extrinsic factors of tendinopathy in order to reduce the risk of subcutaneous rupture.

Successive tendon injury in an in vivo rat overload model induces early damage and acute healing responses

Introduction: Tendinopathy is a degenerative condition resulting from tendons experiencing abnormal levels of multi-scale damage over time, impairing their ability to repair. However, the damage markers associated with the initiation of tendinopathy are poorly understood, as the disease is largely characterized by end-stage clinical phenotypes. Thus, this study aimed to evaluate the acute tendon responses to successive fatigue bouts of tendon overload using an in vivo passive ankle dorsiflexion system. Methods: Sprague Dawley female rats underwent fatigue overloading to their Achilles tendons for 1, 2, or 3 loading bouts, with two days of rest in between each bout. Mechanical, structural, and biological assays were performed on tendon samples to evaluate the innate acute healing response to overload injuries. Results: Here, we show that fatigue overloading significantly reduces in vivo functional and mechanical properties, with reductions in hysteresis, peak stress, and loading and unloading moduli. Multi-scale structural damage on cellular, fibril, and fiber levels demonstrated accumulated micro-damage that may have induced a reparative response to successive loading bouts. The acute healing response resulted in alterations in matrix turnover and early inflammatory upregulations associated with matrix remodeling and acute responses to injuries. Discussion: This work demonstrates accumulated damage and acute changes to the tendon healing response caused by successive bouts of in vivo fatigue overloads. These results provide the avenue for future investigations of long-term evaluations of tendon overload in the context of tendinopathy.

Current concept review of Achilles tendinopathy

Achilles tendinopathy is a common overuse injury affecting the ankle and foot. It manifests as a clinical condition that includes pain, edema, and decreased functionality. This condition can be broadly categorized into two main types based on anatomical location: insertional and noninsertional tendinopathy. The development of Achilles tendinopathy involves various factors, both internal and external. Patients with Achilles tendinopathy often experience stiffness worsened by prolonged rest, and pain exacerbated by physical activity. These symptoms can limit work activity and sports participation, with many patients facing discomfort while wearing shoes due to heel sensitivity. Diagnosis is primarily clinical, although MRI and ultrasound imaging can aid in differential diagnosis. Identifying risk factors and understanding the patient's biomechanics assist in accurate diagnosis and subsequent management. Management of Achilles tendinopathy involves a range of conservative and surgical options. However, due to varying results in clinical studies, a definitive gold standard treatment has not emerged. Eccentric exercises are a valuable tool in managing the condition. The recommend treatments such as shock wave therapy or nitric oxide patches are sought if symptoms do not improve. Peritendinous injections could be options if physical therapy proves ineffective. Surgical intervention is required after six months of conservative treatment. Recent research on Achilles tendinopathy emphasizes the need for individualized treatment plans that address its multifaceted nature. Combining biomechanical analysis, advanced imaging, and patient-specific factors is key to achieving optimal outcomes. Additionally, preventive strategies focusing on proper training techniques, load management, and addressing modifiable risk factors play a critical role in reducing the incidence of this condition. In conclusion, this article provides a current overview of Achilles tendinopathy. It highlights the importance of a comprehensive approach to understanding its causes, pathophysiology, diagnosis, and management strategies.

A pilot study exploring the use of hyaluronic acid in treating insertional achilles tendinopathy

PURPOSE

This study explores the use of ultrasound-guided Hyaluronic Acid (HA) injections for Insertional Achilles Tendinopathy (IAT).

METHODS

A cohort of 15 ankles diagnosed with IAT received three weekly ultrasound-guided HA injections. The Victorian Institute of Sport Assessment - Achilles (VISA-A) questionnaire scored the severity of symptoms and functional impairment before treatment, and at one and six months post-treatment.

RESULTS

Significant improvement was observed in VISA-A scores post-treatment, rising from an average baseline of 34.8 ± 15.2 (11-63) to 53.6 ± 20.9 (15-77) after one month, and then to 50.7 ± 18.6 (20-75) after six months. No adverse reactions were noted, underscoring the safety of the intervention.

CONCLUSION

The pilot study presents HA injections as a potentially effective treatment for IAT, while interpretation of these findings must take into account the variability in results, indicating a range of patient responses. It encourages further research to confirm these findings and to explore HA's full potential in managing IAT, despite the limitations of a small sample size and lack of control group.

Galangin Promotes Tendon Repair Mediated by Tendon-Derived Stem Cells through Activating the TGF-β1/Smad3 Signaling Pathway

Tendon injury is a prevalent orthopedic disease that currently lacks effective treatment. Galangin (GLN) is a vital flavonoid found abundantly in galangal and is known for its natural activity. This study aimed to investigate the GLN-mediated molecular mechanism of tendon-derived stem cells (TDSCs) in tendon repair. The TDSCs were characterized using alkaline phosphatase staining, alizarin red S staining, oil red O staining, and flow cytometry. The effect of GLN treatment on collagen deposition was evaluated using Sirius red staining and quantitative (q)PCR, while a Western bot was used to assess protein levels and analyze pathways. Results showed that GLN treatment not only increased the collagen deposition but also elevated the mRNA expression and protein levels of multiple tendon markers like collagen type I alpha 1 (COL1A1), decorin (DCN) and tenomodulin (TNMD) in TDSCs. Moreover, GLN was also found to upregulate the protein levels of transforming growth factor β1 (TGF-β1) and p-Smad3 to activate the TGF-β1/Smad3 signaling pathway, while GLN mediated collagen deposition in TDSCs was reversed by LY3200882, a TGF-β receptor inhibitor. The study concluded that GLN-mediated TDSCs enhanced tendon repair by activating the TGF-β1/Smad3 signaling pathway, suggesting a novel therapeutic option in treating tendon repair.

Optimization of wrist tendon detection in virtual monochromatic images using dual energy-computed tomography

OBJECTIVES

To evaluate the depiction of wrist tendons in virtual monochromatic images (VMIs) during a dual-energy CT (DE-CT) with the VMI image of conventional equivalent to 120 kVp.

MATERIALS AND METHODS

Using Catphan600 and phantom analysis software for CT evaluation, measurements of VMI in a DE-CT were performed corresponding to the tube voltages of single-energy CT at 120 kVp. Using a Discovery CT750 HD CT scanner (GE Healthcare) with DE-CT technology, 73 patients were scanned. We calculated the CT number, image noise, visual score, and contrast noise ratio (CNR) at the extensor pollicis tendon, extensor digitorum tendon, and flexor tendon in 11 VMIs from the DE-CT and VMI image of conventional equivalent to 120 kVp. The results from the optimal VMIs were then compared with that of the VMI image of the conventional equivalent to 120 kVp.

RESULTS

The highest CT number and CNR for the tendon were for the 140 keV VMI in the DE-CT compared to the other energy levels. There were significantly higher CT numbers, CNR values, and visual scores for each tendon at 140 keV VMI with the DE-CT (p < 0.01) compared with a VMI image of conventional equivalent to 120 kVp.

CONCLUSION

Energy level of the VMIs during DE-CT for the best wrist tendon delineation was 140 keV. This value of 140 keV for the DE-CT was significantly higher than the CT number and CNR for the extensor pollicis, extensor digitorum, and flexor tendon compared with a VMI image of conventional equivalent to 120 kVp.

Testosterone replacement therapy is associated with increased odds of Achilles tendon injury and subsequent surgery: a matched retrospective analysis

BACKGROUND

Prescription of testosterone replacement therapy (TRT) has increased in the United States in recent years, and though anabolic steroids have been associated with tendon rupture, there is a paucity of literature evaluating the risk of Achilles tendon injury with TRT. This study aims to evaluate the associative relationship between consistent TRT, Achilles tendon injury, and subsequent surgery.

METHODS

This is a one-to-one matched retrospective cohort study utilizing the PearlDiver database. Records were queried for patients aged 35-75 who were prescribed at least 3 consecutive months of TRT between January 1, 2010 and December 31, 2019. Achilles tendon injuries and subsequent surgeries were identified using ICD-9, ICD-10, and CPT billing codes. Multivariable logistic regression was used to compare odds of Achilles tendon injury, Achilles tendon surgery, and revision surgery, with a p-value < 0.05 representing statistical significance.

RESULTS

A sample of 423,278 patients who filled a TRT prescription for a minimum of 3 consecutive months was analyzed. The 2-year incidence of Achilles tendon injury was 377.8 (95% CI, 364.8-391.0) per 100,000 person-years in the TRT cohort, compared to 245.8 (95% CI, 235.4-256.6) in the control (p < 0.001). The adjusted analysis demonstrated TRT to be associated with a significantly increased likelihood of being diagnosed with Achilles tendon injury (aOR = 1.24, 95% CI, 1.15-1.33, p < 0.001). Of those diagnosed with Achilles tendon injury, 287/3,198 (9.0%) of the TRT cohort subsequently underwent surgery for their injury, compared to 134/2,081 (6.4%) in the control cohort (aOR = 1.54, 95% CI, 1.19-1.99, p < 0.001).

CONCLUSIONS

There is a significant association between Achilles tendon injury and prescription TRT, with a concomitantly increased rate of undergoing surgical management. These results provide insight into the risk profile of TRT and further research into the science of tendon pathology in the setting of TRT is an area of continued interest.

Triceps surae muscle forces during dynamic exercises in patients with Achilles tendinopathy: A cross-sectional study

PURPOSE

The aim of this study was to investigate the individual triceps surae muscle forces during the execution of six different functional movements and rehabilitation exercises in patients with Achilles tendinopathy compared to a control group.

METHODS

Triceps surae muscle forces of 15 participants with Achilles tendinopathy (AT) and 15 healthy controls were estimated through a combination of experimental data and musculo-skeletal modeling. Three-dimensional motion capture and force plates were used to collect the ankle and knee joint angles and moments during three functional movements (walking, heel walking, and toe walking) and three rehabilitation exercises (bilateral heel drop, unilateral heel drop with extended knee and with flexed knee). A dynamic optimization method was used to obtain the modeled triceps surae muscle forces. Force-sharing strategies were calculated at the peak triceps surae muscle force and compared between groups.

RESULTS

Lower peak triceps surae forces were obtained for the AT group during dynamic exercises. Across all exercises, the average contribution of the soleus (SOL) to the total triceps surae muscle force was the largest (60.83 ± 13.89% [AT] > 56.90 ± 16.18% [healthy]), followed by the gastrocnemius medialis (29.87 ± 10.67% [AT] < 32.19 ± 12.90% [healthy]) and the gastrocnemius lateralis (9.30 ± 4.31% [AT] < 10.91 ± 4.66% [healthy]). The triceps surae force-sharing strategy was different for the toe walking, heel walking, and the bilateral and unilateral heel drop with extended knee.

CONCLUSION

This study provides evidence for altered triceps surae muscle force-sharing strategies during dynamic tasks in patients with AT. The influence of altered muscle force-sharing on the subtendon nonuniformity and/or the tendon loading should be explored in future work.

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.

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.

Key Considerations When Targeting a Heel Spur

Heel spur is a common medical condition that can cause substantial discomfort and reduce the quality of life of the affected patients. When seeking treatment for a heel spur, it is important to consider the differential diagnoses and underlying medical conditions that may contribute to the symptoms. This manuscript aims to explore several distinctive diagnostic possibilities, essential factors to consider, and practical strategies for managing heel spurs. This paper explains the common differential diagnoses and addresses medical conditions related to heel spurs. The importance of accurate diagnosis in planning treatment protocol is highlighted. In addition, we explain treatment strategies, including preventive measures, conservative treatments, and more advanced procedures. Physicians can help relieve pain and improve the quality of life of the affected individuals by considering the diverse aspects of managing heel spurs.

[Achilles tendon pathologies]

Achilles tendon pathologies are a frequent problem in the clinical practice. A distinction must be made between insertional and noninsertional tendinopathies. In addition to intrinsic risk factors, such as diabetes mellitus, there are also extrinsic risk factors, such as overuse and running. Sonography, X‑ray imaging and magnetic resonance imaging (MRI) are established imaging methods, depending on the question. The primary treatment includes a conservative approach. First-line treatment includes administration of nonsteroidal anti-inflammatory drugs (NSAID), physical rest and the use of assistive devices. Established conservative treatment procedures include eccentric stretching, shockwave therapy and infiltration with, e.g., platelet-rich plasma. There are numerous other conservative treatment options. After exhausting the conservative treatment options, a surgical approach can be considered. The surgical procedure depends on the clinical symptoms and findings. Established procedures are minimally invasive or endoscopic procedures or even open debridement.

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.

Platelets Rich Plasma Increases Antioxidant Defenses of Tenocytes via Nrf2 Signal Pathway

Tendinopathies are common disabling conditions in equine and human athletes. The etiology is still unclear, although reactive oxygen species (ROS) and oxidative stress (OS) seem to play a crucial role. In addition, OS has been implicated in the failure of tendon lesion repair. Platelet-rich plasma (PRP) is rich in growth factors that promote tissue regeneration. This is a promising therapeutic approach in tendon injury. Moreover, growing evidence has been attributed to PRP antioxidant effects that can sustain tissue healing. In this study, the potential antioxidant effects of PRP in tenocytes exposed to oxidative stress were investigated. The results demonstrated that PRP reduces protein and lipid oxidative damage and protects tenocytes from OS-induced cell death. The results also showed that PRP was able to increase nuclear levels of redox-dependent transcription factor Nrf2 and to induce some antioxidant/phase II detoxifying enzymes (superoxide dismutase 2, catalase, heme oxygenase 1, NAD(P)H oxidoreductase quinone-1, glutamate cysteine ligase catalytic subunit and glutathione, S-transferase). Moreover, PRP also increased the enzymatic activity of catalase and glutathione S-transferase. In conclusion, this study suggests that PRP could activate various cellular signaling pathways, including the Nrf2 pathway, for the restoration of tenocyte homeostasis and to promote tendon regeneration and repair following tendon injuries.

Single-cell and spatial transcriptomics reveal changes in cell heterogeneity during progression of human tendinopathy

BACKGROUND

Musculoskeletal tissue degeneration impairs the life quality and motor function of many people, especially seniors and athletes. Tendinopathy is one of the most common diseases associated with musculoskeletal tissue degeneration, representing a major global healthcare burden that affects both athletes and the general population, with the clinical presentation of long-term recurring chronic pain and decreased tolerance to activity. The cellular and molecular mechanisms at the basis of the disease process remain elusive. Here, we use a single-cell and spatial RNA sequencing approach to provide a further understanding of cellular heterogeneity and molecular mechanisms underlying tendinopathy progression.

RESULTS

To explore the changes in tendon homeostasis during the tendinopathy process, we built a cell atlas of healthy and diseased human tendons using single-cell RNA sequencing of approximately 35,000 cells and explored the variations of cell subtypes' spatial distributions using spatial RNA sequencing. We identified and localized different tenocyte subpopulations in normal and lesioned tendons, found different differentiation trajectories of tendon stem/progenitor cells in normal/diseased tendons, and revealed the spatial location relationship between stromal cells and diseased tenocytes. We deciphered the progression of tendinopathy at a single-cell level, which is characterized by inflammatory infiltration, followed by chondrogenesis and finally endochondral ossification. We found diseased tissue-specific endothelial cell subsets and macrophages as potential therapeutic targets.

CONCLUSIONS

This cell atlas provides the molecular foundation for investigating how tendon cell identities, biochemical functions, and interactions contributed to the tendinopathy process. The discoveries revealed the pathogenesis of tendinopathy at single-cell and spatial levels, which is characterized by inflammatory infiltration, followed by chondrogenesis, and finally endochondral ossification. Our results provide new insights into the control of tendinopathy and potential clues to developing novel diagnostic and therapeutic strategies.

A preliminary investigation into the impact of shock wave therapy and sonotherapy on postural control of stepping tasks in patients with Achilles tendinopathy

Objective

The outcomes of physical therapy are commonly assessed with subjective scales and questionnaires. Hence, a continuous search to identify diagnostic tests that would facilitate objective assessment of symptom reduction in those patients with Achilles tendinopathy who undergo mechanotherapy. The main aim of this study was to evaluate and compare the effectiveness of shock wave and ultrasound treatments, using objective posturographic assessment during step-up and step-down initiation.

Materials and methods

The patients with non-insertional Achilles tendinopathy and pain lasting for more than 3 months were randomly assigned to one of the experimental groups, i.e., radial shock wave therapy (RSWT), ultrasound therapy, or placebo ultrasound. All groups also received deep friction massage as the primary therapy. The transitional locomotor task was performed with the affected and unaffected limb in random order, on two force platforms under two conditions (step-up and step-down). The recording of center of foot pressure displacements was divided into three phases: quiet standing before step-up/step-down, transit, and quiet standing until measurement completion. Pre-intervention measurements were performed and then short-term follow-ups at weeks 1 and 6 post-therapy.

Results

The three-way repeated measures ANOVA showed few statistically significant two-factor interactions between therapy type, time point of measurement and the type of the locomotor task. Significant increases in postural sway were observed in the entire study population throughout the follow-up period. Three-way ANOVAs revealed a group effect (shock wave vs. ultrasound) on almost all variables of the quiet standing phase prior to step-up/step-down initiation. Overall, postural stability before the step-up and step-down tasks appeared to be more efficient in patients who had undergone RSWT compared to the ultrasound group.

Conclusion

Objective posturographic assessment during step-up and step-down initiation did not demonstrate therapeutic superiority of any of the three therapeutic interventions used in patients with non-insertional Achilles tendinopathy.Clinical Trial Registration: The trial was prospectively registered in the Australian and New Zealand Clinical Trials Registry (no. ACTRN12617000860369; registration date: 9.06.2017).

Ankle Sprains in Athletes: Current Epidemiological, Clinical and Imaging Trends

Purpose

Ankle injuries are frequent sports injuries. Despite optimizing treatment strategies during recent years, the percentage of chronification following an ankle sprain remains high. The purpose of this review article is, to highlight current epidemiological, clinical and novel advanced cross-sectional imaging trends that may help to evaluate ankle sprain injuries.

Methods

Systematic PubMed literature research. Identification and review of studies (i) analyzing and describing ankle sprain and (ii) focusing on advanced cross-sectional imaging techniques at the ankle.

Results

The ankle is one of the most frequently injured body parts in sports. During the COVID-19 pandemic, there was a change in sporting behavior and sports injuries. Ankle sprains account for about 16-40% of the sports-related injuries. Novel cross-sectional imaging techniques, including Compressed Sensing MRI, 3D MRI, ankle MRI with traction or plantarflexion-supination, quantitative MRI, CT-like MRI, CT arthrography, weight-bearing cone beam CT, dual-energy CT, photon-counting CT, and projection-based metal artifact reduction CT may be introduced for detection and evaluation of specific pathologies after ankle injury. While simple ankle sprains are generally treated conservatively, unstable syndesmotic injuries may undergo stabilization using suture-button-fixation. Minced cartilage implantation is a novel cartilage repair technique for osteochondral defects at the ankle.

Conclusion

Applications and advantages of different cross-sectional imaging techniques at the ankle are highlighted. In a personalized approach, optimal imaging techniques may be chosen that best detect and delineate structural ankle injuries in athletes.

Lower extremity ultrasound-guided interventions: tendon, ligament, and plantar fascia

Lower extremity tendinopathy and soft tissue injury are common clinical problems that can cause significant disability. Ultrasound-guided minimally invasive treatments using orthobiologics and image-guided percutaneous treatments continue to gain relevance with an ever-growing body of literature. We review the indications, technique, risks, and benefits according to the literature of common ultrasound-guided interventions utilized in the lower extremities.

Return to Sports and Functional Outcomes after Autologous Platelet-Rich Fibrin Matrix (PRFM) and Debridement in Midportion Achilles Tendinopathy: A Case Series with 24-Month Follow-Up

(1) Background: Achilles tendinopathy (AT) is characterized by load-induced tendon pain, stiffness, and functional impairment that may affect the tendon midportion or insertion. Platelet-rich fibrin matrix (PRFM) is a promising adjunctive therapy for AT. We analyzed 24-month pain and functional outcomes in a cohort of patients managed by tendon debridement and autologous PRFM application to determine whether the combined treatment ensured an early return to sports/work and satisfactory clinical outcomes and functional scores. (2) Methods: The 24-month outcomes of 32 sport-practicing patients with chronic midportion AT treated with debridement and autologous PRFM were evaluated in terms of time to return to sports/work. The AOFAS and VISA-A were computed preoperatively and at 6 and 24 months. Blazina scores were evaluated preoperatively and at 6 months; ankle range of motion was assessed at 1, 6, 12, 24 months; and patient satisfaction was assessed at 24 months. (3) Results: Altogether, all patients had resumed their sport(s) activity, at the same or higher level, after 25.41 days (±5.37). Regarding work, all patients were able to return to their jobs after 16.41 days (±2.43). Ankle dorsiflexion and plantarflexion increased significantly: the AOFAS rose from 54.56 (±6.47) to 97.06 (±4.06) and 98.88 (±2.21) at 6 and 12 months, respectively, and the mean VISA-A score rose from 69.16 (±7.35) preoperatively to 95.03 (±4.67) and 97.28 (±2.43) at 6 and 12 months, respectively, after treatment. There were no complications. Most (90.62%) patients were very satisfied. (4) Conclusions: In symptomatic midportion AT, surgical debridement and autologous PRFM ensured a fast return to sports/work (4 weeks), significantly improving AOFAS and VISA-A and Blazina scores already at 6 months and providing excellent clinical outcomes at 24 months.

Endoscopic debridement for non-insertional Achilles tendinopathy with and without platelet-rich plasma

BACKGROUND

When non-operative management fails to improve symptoms in patients with non-insertional Achilles tendinopathy, surgery may be required. Various open and endoscopic techniques have been proposed, and platelet-rich plasma (PRP) injections have been proposed as an adjunct to aid tendon healing.

METHODS

Thirty-six patients with mid-portion Achilles tendinopathy were randomized to undergo endoscopic debridement alone (n = 19) or in combination with intraoperative PRP application (n = 17). Clinical outcome measures included the Visual Analogue Scale for pain, function, and satisfaction and the Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire. Patients were followed-up at 6 weeks, 3 months, 6 months, and 12 months after surgery. An MRI examination at 3 and 12 months was used to assess signal alterations within the tendon.

RESULTS

Both groups showed significant clinical improvement (p < 0.05) after surgery, with no difference between the 2 groups. Tendon diameter increased at 3 months and decreased at 12 months. The tendinopathy area increased at 3 months and decreased at 12 months below baseline level in both groups. There was no significant difference between the groups regarding the MRI parameters. Nodular thickening and MRI-detected signal alteration persisted after surgery, with no association between imaging and clinical outcome. Five minor complications were reported: 2 in the PRP group and 3 in the control group.

CONCLUSION

Endoscopic debridement of the Achilles tendon improved clinical outcomes in patients with mid-portion tendinopathy. The addition of PRP did not improve outcomes compared to debridement alone. MRI parameters showed no association with clinical outcomes.

The Effects of Increasing Trunk Flexion During Stair Ascent on the Rate and Magnitude of Achilles Tendon Force in Asymptomatic Females

Research indicates that increasing trunk flexion may optimize patellofemoral joint loading. However, this postural change could cause an excessive Achilles tendon force (ATF) and injury risk during movement. This study aimed to examine the effects of increasing trunk flexion during stair ascent on ATF, ankle biomechanics, and vertical ground reaction force in females. Twenty asymptomatic females (age: 23.4 [2.5] y; height: 1.6 [0.8] m; mass: 63.0 [12.2] kg) ascended stairs using their self-selected and flexed trunk postures. Compared with the self-selected trunk condition, decreases were observed for peak ATF (mean differences [MD] = 0.14 N/kg; 95% confidence interval [CI], 0.06 to 0.23; Cohen d = -1.2; P = .003), average rate of ATF development (MD = 0.25 N/kg/s; 95% CI, 0.07 to 0.43; Cohen d = -0.9; P = .010), ankle plantar flexion moment (MD = 0.08 N·m/kg; 95% CI, 0.03 to 0.13; Cohen d = -1.1; P = .005), and vertical ground reaction force (MD = 38.6 N/kg; 95% CI, 20.3 to 56.90; Cohen d = -1.8; P < .001). Increasing trunk flexion did not increase ATF. Instead, this postural change was associated with a decreased ATF rate and magnitude and may benefit individuals with painful Achilles tendinopathy.

Intratendinous pressure changes in the Achilles tendon during stretching and eccentric loading: Implications for Achilles tendinopathy

Mechanical overload is considered the main cause of Achilles tendinopathy. In addition to tensile loads, it is believed that the Achilles tendon may also be exposed to compressive loads. However, data on intratendinous pressures are lacking, and consequently, their role in the pathophysiology of tendinopathy is still under debate. Therefore, we aimed to evaluate the intratendinous pressure changes in the Achilles tendon during stretching and eccentric loading. Twelve pairs of human cadaveric legs were mounted in a testing rig, and a miniature pressure catheter was placed through ultrasound-guided insertion in four different regions of the Achilles tendon: the insertion (superficial and deep layers), mid-portion, and proximal portion. Intratendinous pressure was measured during three simulated loading conditions: a bent-knee calf stretch, a straight-knee calf stretch, and an eccentric heel-drop. It was found that the intratendinous pressure increased exponentially in both the insertion and mid-portion regions of the Achilles tendon during each loading condition (p < 0.001). The highest pressures were consistently found in the deep insertion region (p < 0.001) and during the eccentric heel-drop (p < 0.001). Pressures in the mid-portion were also significantly higher than in the proximal portion (p < 0.001). These observations offer novel insights and support a role for compression in the pathophysiology of Achilles tendinopathy by demonstrating high intratendinous pressures at regions where Achilles tendinopathy typically occurs. To what extent managing intratendinous pressure might be successful in patients with Achilles tendinopathy by, for example, avoiding excessive stretching, modifying exercise therapy, and offering heel lifts requires further investigation.

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.

Interventional Imaging Techniques as Alternative to Surgery of the Foot and Ankle

A variety of foot and ankle pathologies can impair patient's daily activities, ultimately requiring surgical management. However, with improvements in image-guided intervention, the joints, soft tissues, and osseous structures may be accessible using various percutaneous techniques as a potential alternative therapeutic tool, avoiding the need for surgery with its associated risks and morbidity. This article discusses the potential range of image-guided interventional treatments. Injections, aspiration, biopsies, cryoablation, and radiofrequency ablation are described. Newer novel treatments are also covered. Finally, the common pathologies of Morton's neuroma, Achilles tendinopathy, and plantar fasciitis are addressed.

Synthetic Graft Augmentation Is Safe and Effective for the Repair of Acute Achilles Tendon Rupture in Patients With Preexisting Tendinopathy

Purpose

To assess the safety and report the clinical outcomes of synthetic graft augmentation using polypropylene (PP) mesh in the repair of acute Achilles tendon (AT) rupture in patients with preexisting tendinopathy. Methods: Patients who underwent open repair for acute AT rupture at our institution between April 2017 and March 2019 were retrospectively identified. The inclusion criteria were acute AT rupture in patients with preexisting tendinopathy. All patients included in the study underwent acute repair augmented by an inlay PP mesh and had 30 months' follow-up. Patient characteristics, operative details, and outcomes were analyzed. Continuous data were described by mean, standard deviation, median, and range. The Wilcoxon signed rank test was used to analyze the change in patient-reported outcome measures. The significance level was set at a P-value of .05.

Results

Thirteen patients were included. There were 5 female and 8 male patients, withan average age of 52 years (range 49-56 years). No cases of rerupture or graft-related complications requiring additional treatment occurred during mean follow -up of 38 months. All patients reported good functional outcome, as shown from nonsignificant difference between the preinjury and 38-month postoperative Achilles Tendon Rupture Score (88.5 ± 2.2 vs 89.2 ± 2.2, P = .107) and the excellent postoperative American Orthopedic Foot and Ankle Society Ankle/Hindfoot Scale score (92.22 ± 2.2) at last follow-up. At the end of follow-up, all patients were able to perform single-legged heel rise as the noninvolved side. By average of 16 weeks, all patients returned to their preinjury activity level.

Conclusions

The use of inlay PP mesh to augment the repair of acute AT rupture in patients with preexisting tendinopathy appears to be safe and effective, allowing early return to preinjury activity level with favorable clinical outcomes.

Level of Evidence

Level IV, therapeutic case series.

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.

Adipose cellular injection in the treatment of an intrasubstance Achilles tendon defect: a case report

Our patient presented with a 1-year history of right sided Achilles tendon pain and weakness due to partial intrasubstance tear. The injury was refractory to conservative treatment, leading to a trial injection of microfragmented adipose tissue. Progressive healing and improved function were documented on physical exam and sonographically at subsequent follow-up appointments. About 4 weeks following the injection, the patient was able to return to his regular activity level. At the 6 month follow-up appointment, the patient continued to be pain free and had resumed all prior activities without limitations. This case highlights the potential microfragmented adipose tissue has as a regenerative treatment modality for the management of partial Achilles tendon tears.

Evaluation of SS-31 as a Potential Strategy for Tendinopathy Treatment: An In Vitro Model

BACKGROUND

Studies in our laboratory have demonstrated mitochondrial dysfunction in human and animal models of supraspinatus tendinopathy. SS-31 (elamipretide) has been reported to improve mitochondrial function and to be effective in clinical trials for several diseases. The potential of SS-31 in treating tendinopathy has not been explored.

HYPOTHESIS

SS-31 would improve mitochondrial function in human tenocytes sampled from patients with tendinopathy.

STUDY DESIGN

Controlled laboratory study.

METHODS

Healthy tenocytes were obtained from normal hamstring tendon biopsy specimens in 9 patients undergoing anterior cruciate ligament reconstruction, and tenocytes were collected from degenerative supraspinatus tendon biopsy specimens in 9 patients undergoing rotator cuff repair. Tenocytes were cultured, used at passage 1, and assigned to 4 groups: healthy tenocytes, healthy tenocytes with 1μM SS-31 treatment for 72 hours, degenerative tenocytes, and degenerative tenocytes with 1μM SS-31 treatment for 72 hours. The outcomes included measurements of mitochondrial potential, mitochondrial morphology by transmission electron microscopy imaging, reactive oxygen species and superoxidative dismutase activity, gene expression, and cell viability.

RESULTS

An increase in the cell fraction with depolarized mitochondria was found in degenerative tenocytes (P = .014), followed by a decrease after SS-31 treatment (P = .018). Transmission electron microscopy images demonstrated morphological changes with a decreased number and size of mitochondria per cell in the degenerative tenocytes (P = .018) and with improvement after SS-31 treatment. There was no significant difference in the level of reactive oxygen species between healthy and degenerative tenocytes in culture, but superoxidative dismutase activity was significantly decreased in the degenerative group (P = .006), which then increased after SS-31 treatment (P = .012). These findings suggested that mitochondrial dysfunction may be reversed by SS-31 treatment. The gene expression of matrix metalloproteinase-1 (matrix remodeling, P = .029) and fatty acid-binding protein 4 (fatty infiltration, P = .046) was significantly upregulated in the degenerative tenocytes and reduced by SS-31 treatment (P = .048; P = .007). Gene expression for hypoxia-inducible factor1 α and the proapoptotic regulator Bcl-2-associated X protein was increased in the degenerative tenocytes. There was a significant decrease in cell viability in degenerative tenocytes as compared with the healthy tenocytes, with small improvement after treatment with SS-31.

CONCLUSION

There are changes in mitochondrial structure and function in tenocytes derived from degenerative tendons, and SS-31, as a mitochondrial protectant, could improve mitochondrial function and promote the healing of tendinopathy.

CLINICAL RELEVANCE

Mitochondrial dysfunction appears to play a role in the development of tendinopathy, and SS-31, as a mitochondrial protective agent, may be a therapeutic agent in the treatment of tendinopathy.

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.

Features of Extrinsic Plantar Muscles in Patients with Plantar Fasciitis by Ultrasound Imaging: A Retrospective Case Control Research

The present study aimed to compare by ultrasound imaging (USI) the tibial posterior (TP), medial gastrocnemius (MG) and soleus muscle in patients with and without plantar fasciitis (PF). A sample of 42 individuals was recruited and divided into two groups: PF and a healthy group. The thickness, cross-sectional area (CSA), echointensity and echovariation were assessed in both groups by USI. TP, soleus and MG variables did not report differences (p > 0.05) for thickness and CSA. For the echotexture parameters significant differences were found for MG echointensity (p = 0.002), MG echovariation (p = 0.002) and soleus echointensity (p = 0.012). Non-significant differences (p > 0.05) were reported for soleus echovariation, TP echointensity and TP echovariation variables. The thickness and CSA of the TP, GM and soleus muscle did not show significant differences between individuals with and without PF measured by USI. Muscle quality assessment reported an increase of the MG echointensity and echovariation, as well as a decrease of echointensity of the soleus muscle in the PF group with respect to the healthy group. Therefore, the evaluation of the structure and muscle quality of the extrinsic foot muscles may be beneficial for the diagnosis and monitoring the physical therapy interventions.

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.

Current understanding of the diagnosis and management of the tendinopathy: An update from the lab to the clinical practice

Tendinopathy is labeled by many authors as a troublesome, common pathology, present in up to 30% medical care consultations involving musculoskeletal conditions. Despite the lasting interest for addressing tendon pathology, current researchers agree that even the exact definition of the term tendinopathy is unclear. Tendinopathy is currently diagnosed as a clinical hypothesis based on the patient symptoms and physical context. One of the main goals of current clinical management is to personalize treatment approaches to adapt them to the many different needs of the population. Tendons are complex structures that unite muscles and bones with two main objectives: to transmit forces and storage and release energy. Regarding the tensile properties of the tendons, several authors argued that tendons have higher tensile strength compared with muscles, however, are considered less flexible. Tendinopathy is an accepted term which is used to indicated a variety of tissue conditions that appear in injured tendons and describes a non-rupture damage in the tendon or paratendon, which is intensified with mechanical loading Even when the pathoetiology of tendinopathy is unclear, there is a wide array of treatments available to treat and manage tendinopathy. Although tendinitis usually debuts with an inflammatory response, the majority of chronic tendinopathies do not present inflammation and so the choosing of treatment should vary depending on severity, compliance, pain and duration of symptoms. The purpose of this article is to review and provide an overview about the currently research of the tendon diagnosis, management and etiology.

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.

A problem-based approach in musculoskeletal ultrasonography: heel pain in adults

Musculoskeletal ultrasonography (US) has unique advantages, such as excellent spatial resolution for superficial structures, the capability for dynamic imaging, and the ability for direct correlation and provocation of symptoms. For these reasons, US is increasingly used to evaluate problems in small joints, such as the foot and ankle. However, it is almost impossible to evaluate every anatomic structure within a limited time. Therefore, US examinations can be faster and more efficient if radiologists know where to look and image patients with typical symptoms. In this review, common etiologies of heel pain are discussed in a problem-based manner. Knowing the common pain sources and being familiar with their US findings will help radiologists to perform accurate and effective US examinations.

Long Term Clinical-Functional and Ultrasound Outcomes in Recreational Athletes after Achilles Tendon Rupture: Ma and Griffith versus Tenolig

Background and Objectives: The purpose of this retrospective study was to compare the long-term clinical-functional and ultrasound outcomes of recreational athletes treated with two percutaneous techniques: Ma and Griffith (M&G) and the Tenolig technique (TT). Materials and Methods: recreational athletes, between 18 and 50 years of age, affected by acute Achilles tendon rupture (AATR), treated by M&G or Tenolig techniques were recruited. Clinical-functional outcomes were evaluated using Achilles Tendon Rupture Score (ATRS), AOFAS Ankle-Hindfoot score, VAS (for pain and satisfaction) questionnaires, and ultrasound analysis (focal thickening, hypoechoic areas, presence of calcifications, tendinitis and alteration of normal fibrillar architecture). Results: 90 patients were included: 50 treated by M&G, 40 by TT. In all, 90% of patients resumed sports activities, with pre-injury levels in 56% of cases after M&G and in 60% after TT. In the M&G group, the averages of the questionnaires were ATRS 90.70 points, AOFAS 91.03, VAS satisfaction 7.08, and VAS pain 1.58. In the TT group: ATRS 90.38 points, AOFAS 90.28, VAS satisfaction 7.76, and VAS pain 1.34. The TT group showed a significantly higher satisfaction and return to sport activities within a shorter time. In the M&G group, ultrasound check showed a significantly greater incidence of thickening and an alteration of fibrillar architecture in the treated tendon. Three infections were reported, including one deep after M&G, two superficial in the TT group, and two re-ruptures in the Tenolig group following a further trauma. Conclusions: At long-term follow-up, M&G and TT are both valid techniques for the treatment of AATRs in recreational athletes, achieving comparable clinical-functional results. However, TT seems to have a higher patient satisfaction rate, a faster return to sports and physical activities, and fewer ultrasound signs of tendinitis. Finally, the cost of the device makes this technique more expensive.

Potential Long-Term Health Problems Associated with Ultra-Endurance Running: A Narrative Review

It is well established that physical activity reduces all-cause mortality and can prolong life. Ultra-endurance running (UER) is an extreme sport that is becoming increasingly popular, and comprises running races above marathon distance, exceeding 6 h, and/or running fixed distances on multiple days. Serious acute adverse events are rare, but there is mounting evidence that UER may lead to long-term health problems. The purpose of this review is to present the current state of knowledge regarding the potential long-term health problems derived from UER, specifically potential maladaptation in key organ systems, including cardiovascular, respiratory, musculoskeletal, renal, immunological, gastrointestinal, neurological, and integumentary systems. Special consideration is given to youth, masters, and female athletes, all of whom may be more susceptible to certain long-term health issues. We present directions for future research into the pathophysiological mechanisms that underpin athlete susceptibility to long-term issues. Although all body systems can be affected by UER, one of the clearest effects of endurance exercise is on the cardiovascular system, including right ventricular dysfunction and potential increased risk of arrhythmias and hypertension. There is also evidence that rare cases of acute renal injury in UER could lead to progressive renal scarring and chronic kidney disease. There are limited data specific to female athletes, who may be at greater risk of certain UER-related health issues due to interactions between energy availability and sex-hormone concentrations. Indeed, failure to consider sex differences in the design of female-specific UER training programs may have a negative impact on athlete longevity. It is hoped that this review will inform risk stratification and stimulate further research about UER and the implications for long-term health.

Achilles Tendinopathy, A Brief Review and Update of Current Literature

ABSTRACT

Chronic pain in the Achilles tendon is a common problem in both athletes and nonathletes alike. The etiology for the development of Achilles tendinopathy has not been fully elucidated, and there remains multiple theories to explain the pain and dysfunction accompanying this condition. The diagnosis of Achilles tendon problems continues to rely on the clinical history and physical examination. The optimal management of pain, restoration of function, and return-to-sports participation with Achilles tendinopathy are evolving because of the advancement in technologies and research regarding its pathophysiology. This article aims to provide a brief review of the relevant anatomy, differential diagnosis, imaging findings, and an update of the literature on conservative and minimally invasive managements of chronic Achilles tendinopathy.

Achilles Tendinopathy: Evaluation, Rehabilitation, and Prevention

ABSTRACT

Achilles tendinopathy is a common overuse condition that is characterized by degenerative, cumulative tissue microtrauma. It is largely a clinical diagnosis in which the patient typically presents with localized pain that is worse with tendon-loading activities. Imaging modalities may be helpful with the diagnosis of difficult cases or in the planning of interventional procedures. Midportion (noninsertional) and insertional tendinopathy have distinct features and differences for therapeutic paradigms. Overall, Achilles tendinopathy has a good clinical prognosis with most patients improving with activity modification and rehabilitation, with a focus on progressive tendon-loading. Recalcitrant cases may require adjuvant treatment with procedures (e.g., injections, shockwave therapy) and rarely surgical intervention.

Extensive Ossification of the Achilles Tendon with and without Acute Fracture: A Scoping Review

Extensive Ossification of the Achilles Tendon (EOAT) is an uncommon condition characterized by the presence of heterotopic ossification within the substance of the Achilles Tendon and is distinct from other tendinopathies associated with tendon mineralization. The purpose of this scoping review of the literature on EOAT is to describe the pathogenesis, patient population, presentation, management, and outcomes of this rare condition. Fifty-four articles were included in the scoping review after screening and selection. According to the literature, EOAT often presents with pain and swelling around the Achilles Tendon and is frequently associated with acute trauma. EOAT is more common in men, and although the exact mechanisms of the pathology are not fully understood, EOAT may demonstrate specific molecular signaling patterns. The lack of knowledge regarding the molecular mechanism may be a significant hindrance to the management of the condition. Even though a standard treatment regimen for EOAT does not exist, conservative management for six months in patients without complications is recommended. Those who have an acute fracture of the ossification should be managed more aggressively and will often require surgical repair with autograft, although there is no standardized procedure at this time. Clinicians should be aware of the typical presentation, risk factors, and management options of patients with EOAT. Additionally, they should be cautious when selecting treatment strategies and conduct a thorough evaluation of long-term outcomes with various treatment modalities, which this review provides. Most important, this review highlights the need for further research to determine the best course of clinical treatment of EOAT injuries, in order to establish a standard treatment regimen.