Achilles tendon injuries

Bibliometric Analysis of the Top 50 Most Cited Studies on Achilles Tendon Pathology

Background

The development of Achilles tendon treatment modalities has been rapid, and it is increasingly difficult for clinicians to stay up to date with the most influential studies in this field. In order to fully understand the current state of the literature regarding Achilles tendon injury, it is invaluable to be familiar with the foundational articles and studies upon which the field is built.

Purpose

To objectively determine the 50 most frequently cited studies in Achilles tendon pathology and to conduct a bibliometric analysis.

Study Design

Cross-sectional study.

Methods

The Clarivate Analytics Web of Knowledge database was used to gather data and metrics of Achilles tendon research. The 50 most cited articles were selected for analysis from an initial 17,244 identified articles. The information extracted for each article included author name, publication year, country of origin, journal name, study type, and level of evidence.

Results

For these 50 studies, the total number of citations was calculated to be 13,159, with a mean of 263.2 citations per paper. The most cited article collected 657 citations. The publication dates of the 50 studies included in this analysis spanned 41 years (1972-2013). The largest number of articles were published by Swedish authors (n = 14); however, many other countries were represented, including Canada and Finland (n = 6 articles each). The most prevalent study designs were cohort studies (n = 13) with level 4 evidence studies being the most common (n = 14).

Conclusion

Among the 50 most influential articles in Achilles tendon pathology, the study designs most commonly used were cohort studies and review articles. Sweden was the country of origin for the most studies included on this list, which reflects this country's interest and commitment to researching Achilles tendon injuries and treatments.

Combined Midportion Achilles and Plantaris Tendinopathy: A 1-Year Follow-Up Study after Ultrasound and Color-Doppler-Guided WALANT Surgery in a Private Setting in Southern Sweden

Background and Objectives: Chronic painful midportion Achilles combined with plantaris tendinopathy can be a troublesome condition to treat. The objective was to prospectively follow patients subjected to ultrasound (US)- and color doppler (CD)-guided wide awake, local anesthetic, no-tourniquet (WALANT) surgery in a private setting. Material and Methods: Twenty-six Swedish patients (17 men and 9 women, mean age 50 years (range 29–62)) and eight international male patients (mean age of 38 years (range 25–71)) with combined midportion Achilles and plantaris tendinopathy in 45 tendons altogether were included. All patients had had >6 months of pain and had tried non-surgical treatment with eccentric training, without effect. US + CD-guided surgical scraping of the ventral Achilles tendon and plantaris removal under local anesthesia was performed on all patients. A 4–6-week rehabilitation protocol with an immediate full-weight-bearing tendon loading regime was used. The VISA-A score and a study-specific questionnaire evaluating physical activity level and subjective satisfaction with the treatment were used for evaluation. Results: At the 1-year follow-up, 32/34 patients (43 tendons) were satisfied with the treatment result and had returned to their pre-injury Achilles tendon loading activity. There were two dropouts (two tendons). For the Swedish patients, the mean VISA-A score increased from 34 (0–64) before surgery to 93 (61–100) after surgery (p < 0.001). There were two complications, one wound rupture and one superficial skin infection. Conclusions: For patients suffering from painful midportion Achilles tendinopathy and plantaris tendinopathy, US + CD-guided surgical Achilles tendon scraping and plantaris tendon removal showed a high satisfaction rate and good functional results 1 year after surgery.

Exploring new therapeutic potentials of curcumin against post-surgical adhesion bands

BACKGROUND

Adhesion band formation is a common cause of morbidity for patients undergoing surgeries. Anti-inflammatory and anti-fibrotic properties of curcumin, a pharmacologically active component of Curcuma longa, have been investigated in several studies. The aim of this study is to explore the therapeutic potential of curcumin in attenuating post-operative adhesion band (PSAB) formation in both peritoneal and peritendinous surgeries in animal models.

METHODS

Bio-mechanical, histological and quantitative evaluation of inflammation, and total fibrosis scores were graded and measured in the presence and absence of phytosomal curcumin.

RESULTS

Results showed that phytosomal curcumin significantly decreased severity, length, density and tolerance of mobility of peritendinous adhesions as well as incidence and severity of abdominal fibrotic bands post-surgery. Curcumin may decrease inflammation by attenuating recruitment of inflammatory cells and regulating oxidant/anti-oxidant balance in post-operative tissue samples. Moreover, markedly lower fibrosis scores were obtained in the adhesive tissues of phytosomal curcumin-treated groups which correlated with a significant decrease in quantity, quality and grading of fibers, and collagen deposition in animal models.

CONCLUSION

These results suggest that protective effects of phytosomal curcumin against PSAB formation is partially mediated by decreasing inflammation and fibrosis at site of surgery. Further studies are needed to investigate the therapeutic potential of this molecule in preventing PSAB.

Taping-induced cutaneous stimulation to the ankle tendons reduces minimum toe clearance variability

Large variability of minimum toe clearance (MTC) leads to a higher risk of tripping. Visual feedback-based gait training systems have been used to regulate MTC distribution, but these systems are expensive and bulky. Furthermore, the effect of such training lasts only for a short period of time. Considering the efficacy of elastic adhesive tape-induced cutaneous stimulation to the ankle tendons in improving proprioception and movement detection, we hypothesize that application of tapes to the ankle tendons as a practical method for modifying MTC distribution. To test this hypothesis, we recruited 13 young and healthy adults and instructed them to walk on a treadmill under four conditions: no taping, taping the tibialis anterior tendon, taping the Achilles tendon, and taping both tendons. We measured MTC distribution, lower limb joint angles and muscle activations of the tibialis anterior and gastrocnemius medialis, and compared these outcomes under the four conditions. The application of elastic adhesive tape to the ankle tendons had no significant effect on the average MTC height, but tapes applied to the Achilles tendon and both tendons significantly reduced MTC variability. Taping decreased the variability of some lower limb joint angles, but taping did not induce significant changes in the activation levels of the shank muscles. These results demonstrate that elastic adhesive tape applied to the shank can reduce MTC variability with minimal resistance, inertia and cumbersomeness.

Retrospective multicentre evaluation of common calcaneal tendon injuries in 66 cats. Part 1: study population, injury specification and classification

OBJECTIVES

The objective of the first part of this retrospective multicentre study was to identify and classify common calcaneal tendon (CCT) injuries in a study population of 66 cats.

METHODS

The medical records of five different small animal referral centres and veterinary teaching hospitals between 2010 and 2020 were reviewed. In addition to patient-specific data, CCT injuries were characterised in detail. Diagnostic modalities and further comorbidities were recorded.

RESULTS

Sixty-six cats met the inclusion criteria. The mean age of the cats was 7.5 years (range 0.5-16.3) and their mean body weight (BW) was 4.6 kg (range 1.5-9.0). Thirty-four spayed females (51.5%), five intact females (7.6%) and 27 castrated males (40.9%) were included. Most cases involved closed injuries of the CCT (69.7%). Twenty-one of 46 cats had closed atraumatic injuries (45.7%). Open injuries (30.3%) were most commonly lacerations (65%). Twenty-one injuries were classified as atraumatic (31.8%), whereas 25 were traumatic (37.9%). With every year of age, the odds of having an atraumatic injury increased by a factor of 1.021. Cats with atraumatic injuries had a higher mean BW than cats with traumatic injuries, but the difference was not statistically significant. Acute injuries were recorded in 40.9% of cases, whereas 51.5% of cats had a subacute CCT injury and 7.6% had chronic lesions. Most acute lesions were Meutstege type I injuries (55.6%). Subacute and chronic lesions were more commonly Meutstege type IIc injuries (58.8% and 60%, respectively). Considering all CCT injuries, a Meutstege type IIc injury was most common (53%).

CONCLUSIONS AND RELEVANCE

The most common type of injury was Meutstege type IIc. Cats with atraumatic injuries had a higher mean BW than cats with traumatic injuries, but the difference was not statistically significant. Older cats more commonly presented with atraumatic CCT injuries.

Effect of Myofascial Release (MFR) on Tendo Achilles (TA) Flexibility in Nurses: A Review

Increased muscle stiffness can result in a reduced range of motion (ROM) and impaired function. An increased ankle injury risk has been associated with reduced ankle dorsiflexion ROM. Although self-myofascial release (SMFR) is commonly used in clinical and sporting settings, little is known about its impact on gastrocnemius and Achilles tendon (AT) stiffness. As a result, we investigated how SMFR using a foam roller (FR) affects gastrocnemius-AT complex stiffness and ankle dorsiflexion ROM. According to these results, self-myofascial relaxation of the gastrocnemius and an improvement in ankle dorsiflexion ROM can be accomplished by rolling an FR along the calf. Myofascial release (MFR) is a type of manual therapy that involves stretching the myofascial complex with a light load and for a long duration in order to restore optimal length, relieve pain, and improve function. Viscoelastic deformation is the rapid increase in muscle length following stretching.

Effects of isometric loading intensity on patellar tendon microvascular response

Acute increases in tendon blood flow and oxygenation after stress (i.e., hyperemic response) can enhance tendon recovery. While loading intensity is a fundamental part of resistance training programs, its effects on tendon's hyperemic response are unknown. This study aimed to compare acute changes in total (total hemoglobin [THb]) and oxygenated hemoglobin (HbO₂ ) concentrations in the patellar tendon after isometric exercise at different intensities. Thirteen participants performed 8 (5 s) isometric knee extensions at 25%, 50%, and 75% maximal load (maximal voluntarily isometric contraction [MVIC]), separated by 20 min recovery, prescribed in randomized and counterbalanced order. Changes in patellar tendon THb, HbO₂ and deoxygenated hemoglobin (HHb) in response to exercise at each intensity were measured using near-infrared spectroscopy. Post-exercise, HbO₂ increased with 50% ( η p 2 $$ {\eta}_p^2 $$  = 0.305, f = 5.26, p < 0.01) and 75% ( η p 2 $$ {\eta}_p^2 $$  = 0.245, f = 4.56, p < 0.01) but not 25% ( η p 2 $$ {\eta}_p^2 $$  = 0.088, f = 1.16, p = 0.339) MVIC, while THb increased in 50% ( η p 2 $$ {\eta}_p^2 $$  = 0.305, f = 5.26, p = 0.01) but not 25% ( η p 2 $$ {\eta}_p^2 $$  = 0.067, f = 0.865, p = 0.51) or 75% ( η p 2 $$ {\eta}_p^2 $$  = 0.126, f = 1.729, p = 0.14) MVIC. Additionally, increasing load from 25% to 50% MVIC resulted in greater THb (f = 2.459, p = 0.43), HbO₂ (f = 3.389, p = 0.13) and HHb (f = 0.320, p = 0.01) post-exercise responses, but no differences were observed between 50% and 75% MVIC (THb: f = 0.748, p = 0.59; HbO₂ : f = 0.825, p = 0.54; HHb: f = 0.713, p = 0.62). Our results suggest there is a loading threshold at ~50% MVIC at which the tendon hyperemic response is fully achieved. Training above this intensity is not expected to provide any additional change to the tendon microvascular response. Therefore, moderate loading seems to be sufficient to fully elicit the patellar tendon hyperemic response that's believed to stimulate tendon healing.

Friedelin Alleviates the Pathogenesis of Collagenase-Induced Tendinopathy in Mice by Promoting the Selective Autophagic Degradation of p65

With the development of an aging population, tendinopathy has become a common musculoskeletal disease in the elderly with a high recurrence rate and no curative treatment. The inflammation mediated by NF-κB signaling plays an important role in tendon senescence and degeneration. Friedelin (FR) is a triterpenoid derived from green plants, which has a variety of pharmacological functions, such as analgesia, anti-inflammation, antioxidation, and anti-tumor functions. However, the role and mechanism of FR in tendinopathy are unclear. Here, we found that FR improved the mechanical strength of the Achilles tendon, restored the orderly arrangement of collagen fibers, reduced inflammatory cell infiltration, and promoted tenogenesis, thereby blocking the progression of tendinopathy. Mechanistically, FR promoted the autophagic degradation of p65 by enhancing the interaction between p62 and p65 and effectively inhibited the activation of the NF-κB pathway, thus alleviating the inflammatory response of tenocytes. In addition, FR recruited E3 ubiquitin enzyme RNF182 to increase the K48-linked ubiquitination of p65 and promoted p62-mediated autophagic degradation. Furthermore, blocking ubiquitination reversed the degradation of p65 by FR. Therefore, these findings identify the new pharmacological mechanism of the anti-inflammatory effect of FR and provide a new candidate drug for the treatment of tendinopathy.

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.

Focused Ultrasound Mechanical Disruption of Ex Vivo Rat Tendon

Around 30 million tendon injuries occur annually in the U.S. costing $ 114 billion. Conservative therapies, like dry needling, promote healing in chronically injured tendons by inducing microdamage but have mixed success rates. Focused ultrasound (fUS) therapy can noninvasively fractionate tissues through the creation, oscillation, and collapse of bubbles in a process termed histotripsy; however, highly collagenous tissues, like tendon, have shown resistance to mechanical fractionation. This study histologically evaluates whether fUS mechanical disruption is achievable in tendons. Ex vivo rat tendons (45 Achilles and 44 supraspinatus) were exposed to 1.5-MHz fUS operating with 0.1-10 ms pulses repeated at 1-100 Hz for 15-60 s with peak positive pressures <89 MPa and peak negative pressures <26 MPa; other tendons were exposed to dry needling or sham. Immediately after treatment, tendons were flash-frozen and stained with hematoxylin and eosin (H&E) or alpha-nicotinamide adenine dinucleotide diaphorase ( α -NADH-d) and evaluated by two reviewers blinded to the exposure conditions. Results showed successful creation of bubbles for all fUS-treated samples; however, not all samples showed histological injury. When the injury was detected, parameter sets with shorter pulses (0.1-1 ms), lower acoustic pressures, or reduced treatment times showed mechanical disruption in the form of fiber separation and fraying with little to no thermal injury. Longer pulses or treatment times showed a combination of mechanical and thermal injury. These findings suggest that mechanical disruption is achievable in tendons within a small window of acoustic parameters, supporting the potential of fUS therapy in tendon treatment.

Comparison of Ellagic Acid and NSAI Agents in the Treatment of Achilles Tendon Lacerations: An Experimental Study in Rabbits

Objective

Although Achilles tendon ruptures can have many causes, they are known to develop most commonly with trauma. Nonsteroidal anti-inflammatory drugs (NSAID) and low doses of corticosteroids are used in the medical treatment of tendon ruptures. Ellagic acid (EA), which also has an anti-inflammatory effect, has been reported to show its effect via cyclooxygenase 2 (COX2) inhibition as well. The effects of EA and diclofenac sodium on tendon healing were compared in this study.

Methods

We used a total of 18 male New Zealand rabbits in 3 groups with 6 in each. The study was performed under general anesthesia with a xylazine-ketamine combination. After a defect was created in the right Achilles tendon of all the rabbits, group I was administered diclofenac sodium and group II was administered EA for 1 week, whereas the control group (group III) was not administered anything. Postoperative follow-up was provided for all groups.

Results

Euthanasia was performed in all subjects at the end of the eighth week, and the tendons were compared in terms of macroscopic and histopathologic features and tensile resistance. Although there was no statistically significant difference in the tensile resistance Newton values of group I and group II, these values were higher than in the control group, and the NSAI group values were statistically significantly higher than in the control group.

Conclusions

We concluded that EA and NSAIs could be effective in the recovery of tendon integrity and tensile strength and increasing the movement capacity in pathology caused by tendon damage because of their anti-inflammatory features.

The plantaris muscle - Anatomical curiosity or a structure with important clinical value? - A comprehensive review of the current literature

PURPOSE

Although the plantaris muscle is vestigial in humans, it is far too important to remain omitted. The aim of this study is to provide a comprehensive review of the existing literature focused on plantaris muscle clinical value, grafting usefulness and its morphological variations. Hopefully this study will be of great use for every medical practitioner due to its clarity and conciseness despite such broaden scope of this article.

MATERIAL AND METHODS

The article is written based on 100 studies published since 1868 until 2020. During careful selection process 12 papers were dismissed due to their insufficient sample size, wrong methods used or results that were previously discovered.

RESULTS

Many aspects concerning the plantaris muscle are already well examined, summarized and described. However this study has shown how much we still do not know and which fields require further investigations.

CONCLUSION

The anatomical variations of plantaris muscle morphology may cause mid-portion Achilles tendinopathy, tennis leg syndrome or increase the risk of failure while harvesting the tendons.

Kite String Injury Causing a Complete Tear of the Tendoachilles

Kite flying is a common activity in many countries, particularly India. Fierce competition has led to the use of dangerous kite threads like manja (which is a cotton or nylon thread coated with powdered glass) to gain an edge over rivals. The sharp manja can not only cause linear abrasions or deep incised wounds among flyers but it can inflict equally serious injuries to onlookers or unwary pedestrians and two-wheeler riders on the street. Hand, throat, angle of mouth, nose, and feet are some common sites of injury. We report a case of a 62-year-old man who sustained a manja cut injury through the tendoachilles while walking on the roadside when his foot got entangled in the barely visible thin thread as a bicycle rushed past him. The wound was debrided and tendoachilles repaired using the Krackow technique. The patient had reasonable strength in plantar-flexion and good active range of motion at the ankle when last seen at the one-year follow-up. The aim of this article is to highlight the hazards of manja and the need to revisit and acknowledge the clinical, social, and administrative implications of this unusual but noteworthy mechanism of limb and life-threatening injury.

Percutaneous Zadek osteotomy for the treatment of insertional Achilles tendinopathy

BACKGROUND

Insertional Achilles tendinopathy (IAT) is a challenging common lower extremity disorder, despite several treatment options described in literature. Open dorsal closing wedge calcaneal osteotomy or Zadek Osteotomy (ZO), for the treatment of the IAT has good clinical results but a high rate of postoperative complications. The purpose of this study is to describe percutaneous ZO for the treatment of the IAT and to evaluate its impact on the clinical and functional postoperative outcomes.

METHODS

Twenty-six consecutive patients presenting with unilateral IAT refractory to nonoperative measures were treated with percutaneous ZO. Visual Analogue Scale (VAS) and Foot Function Index Score (FFI) were recorded preoperatively and at final follow-up visit (12±3) months. Postoperative complications, satisfaction, and relief of the pain were also recorded.

RESULTS

The percutaneous ZO showed a significant improvement (p<0.0001) in preoperative to postoperative FFI (from 65±9 to 8±12) and VAS (from 9±1 to 1±2). Two postoperative complications (8%) were observed: a case of symptomatic non-union and hardware pain, both in healthy patients. The overall rate of satisfaction after surgery was (92%). The relief from pain was achieved after an average period of 12 weeks.

CONCLUSIONS

ZO is a safe and effective procedure for the treatment of IAT. The use of a minimally invasive surgical approach is associated with excellent pain reduction (VAS score) and improved clinical function (FFI score). When compared to the open surgical approach, the percutaneous ZO may decrease recovery time and postoperative complications.

LEVEL OF EVIDENCE

III, retrospective case series.

Current advances and research in ultrasound imaging to the assessment and management of musculoskeletal disorders

Currently evidence-based practice has given scientific weight to the physical therapist profession; it is essential that all medical professional and physical therapists know the usefulness of new tools that optimize the effectiveness of their interventions and allow the growing of the scientific knowledge base. The use of ultrasound imaging (USI) by physiotherapists has evolved in recent years, consolidating as an increasingly standardized technique, low cost compared to other imaging techniques, quickly of execution, feasible and reliable tool. USI offers a wide range of opportunities in clinical practice as well as in different research areas. Therefore, ultrasound has been currently used as a diagnostic tool by physicians and in recent years there has been an expansion of the use of ultrasound equipment by non-physicians professionals such as physical therapist or physical trainers, who incorporates USI as a means of assessing musculoskeletal system architecture and composition, musculoskeletal changes in dysfunction, pain or injury conditions, as an interventional technique assisting echo-guided procedures or using the visual real-time information as a biofeedback in control motor approaches, as guiding tool in clinical decisions as well as to improve the understanding of tissue adaptations to exercise or movement. The purpose of this article is to review and provide an overview about the currently research of the USI applications and their benefits for the diagnosis and management in individuals with musculoskeletal conditions.

Mechanotendography in Achillodynia shows reduced oscillation variability of pre-loaded Achilles tendon: a pilot study

The present study focuses on an innovative approach in measuring the mechanical oscillations of pre-loaded Achilles tendon by using Mechanotendography (MTG) during application of a short yet powerful mechanical pressure impact. This was applied on the forefoot from the plantar side in direction of dorsiflexion, while the subject stood on the ball of the forefoot on one leg. Participants with Achilles tendinopathy (AT; n = 10) were compared to healthy controls (Con; n = 10). Five trials were performed on each side of the body. For evaluation, two intervals after the impulse began (0-100ms; 30-100ms) were cut from the MTG and pressure raw signals. The intrapersonal variability between the five trials in both intervals were evaluated using the arithmetic mean and coefficient of variation of the mean correlation (Spearman rank correlation) and the normalized averaged mean distances, respectively. The AT-group showed a significantly reduced variability in MTG compared to the Con-group (from p = 0.006 to p = 0.028 for different parameters). The 95% confidence intervals (CI) of MTG results were disjoint, whereas the 95% CIs of the pressure signals were similar (p = 0.192 to p = 0.601). We suggest from this work that the variability of mechanical tendon oscillations could be an indicative parameter of an altered Achilles tendon functionality.

Mechanotendography in Achillodynia shows reduced oscillation variability of pre-loaded Achilles tendon: a pilot study

The present study focuses on an innovative approach in measuring the mechanical oscillations of pre-loaded Achilles tendon by using Mechanotendography (MTG) during application of a short yet powerful mechanical pressure impact. This was applied on the forefoot from the plantar side in direction of dorsiflexion, while the subject stood on the ball of the forefoot on one leg. Participants with Achilles tendinopathy (AT; n = 10) were compared to healthy controls (Con; n = 10). Five trials were performed on each side of the body. For evaluation, two intervals after the impulse began (0-100ms; 30-100ms) were cut from the MTG and pressure raw signals. The intrapersonal variability between the five trials in both intervals were evaluated using the arithmetic mean and coefficient of variation of the mean correlation (Spearman rank correlation) and the normalized averaged mean distances, respectively. The AT-group showed a significantly reduced variability in MTG compared to the Con-group (from p = 0.006 to p = 0.028 for different parameters). The 95% confidence intervals (CI) of MTG results were disjoint, whereas the 95% CIs of the pressure signals were similar (p = 0.192 to p = 0.601). We suggest from this work that the variability of mechanical tendon oscillations could be an indicative parameter of an altered Achilles tendon functionality.

Multi-differentiation potential is necessary for optimal tenogenesis of tendon stem cells

Background

Tendon injury is a significant clinical problem due to poor healing and a high reinjury rate; successful treatment is limited by our poor understanding of endogenous tendon stem cells. Recent evidence suggests that adult stem cells are phenotypically diverse, even when comparing stem cells isolated from the same tissue from the same individual, and may in fact exist on a spectrum of proliferation and differentiation capacities. Additionally, the relationships between and clinical relevance of this phenotypic variation are poorly understood. In particular, tenogenic capacity has not been studied in comparison to tenogenic differentiation and cell proliferation. Toward this end, we performed a comprehensive assessment of cell proliferation and differentiation capacity toward four connective tissue lineages (tendon, cartilage, bone, and adipose) using tendon stem cell lines derived from single cells released directly from tendon tissue to (1) evaluate the differences, if any, in tenogenic potential, and (2) identify the relationships between differentiation phenotypes and proliferation capacity.

Methods

Tendon stem cells were derived from the endotenon of superficial digital flexor tendon from 3 horses. The cell suspension from each horse was separately plated simultaneously (1) at moderate density to generate a heterogenous population of cells—parent tendon cell line—and (2) at low density to separate single cells from each other to allow isolation of colonies that derive from single mother cells—clonal tendon stem cell lines.

Thirty clonal tendon stem cell lines—10 from each horse—and each parent tendon cell line were assessed for tenogenesis, tri-lineage differentiation, and cell proliferation. Differentiation was confirmed by lineage-specific cell staining and quantified by the relative gene expression of lineage-specific markers. Statistical significance was determined using analysis of variance and post hoc Tukey’s tests.

Results

Three distinct differentiation phenotypes—differentiation potency toward all 4 tissue lineages and two tri-lineage differentiation potencies—were identified in tendon clonal stem cell lines. These phenotypes were differentiation toward (1) tendon, cartilage, bone, and adipose (TCOA); (2) tendon, cartilage, and bone (TCO); and (3) tendon, cartilage, and adipose (TCA). Further, clonal cell lines that differentiated toward all four lineages had the highest expression of scleraxis and mohawk upon tenogenesis. Moreover, cell proliferation was significantly different between phenotypic groups, as evidenced by increased numbers of cumulative cell population doublings in clonal cell lines that did not differentiate toward adipose.

Conclusions

Our study provides evidence of the heterogenous character of adult stem cells and identifies key differences in tendon stem cell differentiation and proliferative potentials from the same individual and from the same tendon. Isolation of tendon stem cell lines with the capacity to differentiate into all four connective tissue lineages may yield improved therapeutic benefits in clinical models of repair and promote a native, regenerative phenotype in engineered tendons. Future studies may be targeted to understanding the functional contributions of each tendon stem cell phenotype in vivo and identifying additional cell phenotypes.

Possible effect of morphological variations of plantaris muscle tendon on harvesting at reconstruction surgery-case report

Purpose

Seemingly a well-known, weak, and vestigial plantaris muscle should not be a revelation. However, recent studies have shown that this structure is incredibly underestimated and perceived only as an infirm flexor of the talocrural joint, the knee joint or a great source of graft tissue. Usually, the origin of this inconspicuous muscle begins at the lateral supracondylar line of the femur and the knee joint capsule. It continues distally, forming a long and slender tendon. In most cases, it inserts onto the calcaneal tuberosity on the medial side of the Achilles tendon. However, many morphological variations have been discovered during anatomical dissections and surgical procedures. Nevertheless, according to the present literature, no other studies presented such a complex insertion variant, with indisputable clinical value and significant proof of development of this forgotten muscle.

Methods

The dissection of the right thigh, knee, crural and talocrural region was performed using standard techniques according to a strictly specified protocol.

Results

Four different insertion points were observed. The first band (A) inserted near to the tarsal canal flexor retinaculum. The second band (B) bifurcates into two branches—B1 and B2. B1 is located on the medial side and B2 is located on the lateral side of the calcaneal tuberosity. The third band (C) is inserted into the superior nonarticular calcaneal surface of the calcaneus anteriorly to the Achilles tendon.

Conclusion

A differently shaped plantaris tendon could be considered a cause of harvesting procedure failure. In the light of new case reports perhaps what we are now witnessing is remodeling and transformation of the Plantaris muscle. If so, the awareness of the influence on the onset of Achilles midportion tendinopathy or a potential role in tibialis posterior conflict can be crucial for every clinician.

Traumatic Double-Level Unilateral Achilles Tendon Rupture: A Case Report

Patient: Male, 46

Final Diagnosis: Unilateral double level Achilles tendon tear

Symptoms: Pain • swelling

Medication: —

Clinical Procedure: Achilles tendon rupture repair

Specialty: Orthopedics and Traumatology

Assessment of Noninvasive Low-Frequency Ultrasound as a Means of Treating Injuries to Suspensory Ligaments in Horses: A Research Paper

Therapeutic ultrasound is a noninvasive technique, which is well tolerated by horses, does not need sedation, and can easily be performed in a routine clinical setting. Twenty-three client-owned sport horses were recruited at Clinica Equina San Biagio and included in this case study. Treatment of the injured suspensory ligament apparatus was administered using an EQ Pro, low-frequency therapeutic unit (38 kHz). The noninvasive treatment consisted of massaging the injured area in combination with a traditional ultrasound gel while maintaining the head of the device in direct contact with the injured area. The results indicate that 20 of the 23 horses in this study benefitted from EQ Pro treatment and, following a routine rehabilitation program, returned to competition status: a success rate of 87%. Furthermore, treatment duration was 3.3 ± 0.4 weeks on average, with a healthy outcome as assessed by ultrasound at 6.8 ± 1.9 weeks. Among the 23 horses in this study, 65% of them benefitted from EQ Pro treatment of a duration of just ≤3.3 weeks. It is concluded that EQ Pro therapy is a promising and effective form of treatment for horses with suspensory ligament injury. It is furthermore rapid and easy to use in the Equine Veterinary Clinic setting and does not require sedation. Future studies should now focus on the mechanisms by which this new treatment activates the healing process of the suspensory ligaments of injured horses.

Optimizing growth factor induction of tenogenesis in three-dimensional culture of mesenchymal stem cells

Adult tissue stem cells have shown promise for the treatment of debilitating tendon injuries. However, few comparisons of stem cells from different tissue sources have been made to determine the optimum stem cell source for treating tendon. Moreover, it is likely that the application of tenogenic growth factors will improve tendon stem cell treatments further, and a comprehensive comparison of a number of growth factors is needed. Thus far, different types of stem cells cannot be evaluated in a high-throughput manner. To this end, we have developed an approach to culture mesenchymal stem cells isolated from bone marrow in collagen type I hydrogels with tenogenic growth factors using economical, commercially available supplies. To optimize growth factors for this assay, FGF-2, TGF-β1, IGF-1, and/or BMP-12 were tested singly and in novel combinations of (1) BMP-12 and IGF-1, (2) TGF-β1 and IGF-1, and/or (3) BMP-12 and FGF-2 over 10 days. Our data suggest that BMP-12 supplementation alone results in the strongest expression of tendon marker genes, controlled contractility of constructs, a higher degree of cell alignment, and tendon-like tissue morphology. This easy-to-use benchtop assay can be used to screen novel sources of stem cells and cell lines for tissue engineering and tendon healing applications.

Ultrasonography Features of the Plantar Fascia Complex in Patients with Chronic Non-Insertional Achilles Tendinopathy: A Case-Control Study

Purpose: The goal of the present study was to assess, by ultrasound imaging (USI), the thickness of the plantar fascia (PF) at the insertion of the calcaneus, mid and forefoot fascial locations, and the calcaneal fat pad (CFP) in patients with Achilles tendinopathy (AT). Methods: An observational case-control study. A total sample of 143 individuals from 18 to 55 years was evaluated by USI in the study. The sample was divided into two groups: A group composed of the chronic non-insertional AT (n = 71) and B group comprised by healthy subjects (n = 72). The PF thicknesses at insertion on the calcaneus, midfoot, rearfoot and CFP were evaluated by USI. Results: the CFP and PF at the calcaneus thickness showed statistically significant differences (P < 0.01) with a decrease for the tendinopathy group with respect to the control group. For the PF midfoot and forefoot thickness, no significant differences (P > 0.05) were observed between groups. Conclusion: The thickness of the PF at the insertion and the CPF is reduced in patients with AT measured by USI.

Ultrasound evaluation of extrinsic foot muscles in patients with chronic non-insertional Achilles tendinopathy: A case-control study

AIM

The purpose of the present study was to compare and quantify with ultrasound imaging (USI) the extensor digitorum longus (EDL), tibialis anterior (TA) and peroneus muscles (PER) muscle thickness and cross-sectional area (CSA) between chronic non-insertional Achilles tendinopathy (AT) and healthy subjects.

METHODS

a sample of 143 individuals was recruited and divided in two groups: chronic non-insertional AT group (n = 71) and a healthy group (n = 72). The thickness and CSA were assessment by USI for EDL, TA and PER muscles in both groups.

RESULTS

The thickness evaluation for the TA muscle increased showing statistically significant differences (P = 0.018) as well as for the thickness of the PER muscles significant differences (P = 0.001) were observed in favor the tendinopathy group. The CSA measurements showed statistically significant differences for a decrease in EDL (P = 0.000), TA (P = 0.001) and PER muscles (P = 0.011) for the tendinopathy group with respect to the control group.

CONCLUSIONS

The CSA of the EDL, TA and PER muscles is reduced in participants with chronic non-insertional AT. The thickness for TA muscle is increased as well as a decrease of PER muscles thickness is presented for the AT group with respect to the control group.

Ultrasonography effectiveness of the vibration vs cryotherapy added to an eccentric exercise protocol in patients with chronic mid-portion Achilles tendinopathy: A randomised clinical trial

Tendinopathy is a very common disease in the general population as well as in athletes. The aim of the present study was to examine the tendon thickness and cross-sectional area (CSA) in subjects with chronic mid-portion Achilles tendinopathy (AT) who engaged in either an eccentric exercise (EE) programme with vibration training or an EE programme combined with cryotherapy. A sample of 61 patients with chronic mid-portion AT were recruited and divided into two groups: EE programme vibration training (n = 30) and EE programme combined with cryotherapy (n = 31). Three ultrasound assessments were performed: pre-intervention and at 4, and at 12 weeks. The comparison of thickness and CSA measures at baseline, 4, and 12 weeks showed a significant (P < 0.05) increase at 0, 2, 4, and 6 cm in maximal isometric contraction and at rest in subjects with chronic mid-portion AT. The EE vibration training resulted in a statistically significant CSA increase compared with the cryotherapy group in patients with chronic mid-portion AT.

Results of minimally invasive Achilles tendon scraping and plantaris tendon removal in patients with chronic midportion Achilles tendinopathy: A longer-term follow-up study

Background:

Treatment with ultrasound and colour Doppler–guided minimally invasive Achilles tendon scraping and plantaris tendon removal has shown promising short-term results in patients with chronic painful midportion Achilles tendinopathy.

Methods:

In a follow-up study, 182 consecutive patients (241 tendons) who had undergone Achilles tendon scraping and plantaris tendon removal were contacted on telephone by an independent investigator. The patients who answered the telephone call were included, and they answered a questionnaire on telephone and then also sent their written answers. The questionnaire included information about patient satisfaction with the result of the treatment, time to return to full Achilles tendon loading activity, and a pain score (Visual Analogue Scale-VAS).

Results:

The follow-up period was 5.8 years (mean) (range of 2–13 years) after surgery. Altogether, 110 patients (136 Achilles tendons), 52 years (mean)(range 18-73) old at surgery could be reached and were included. In total, 81 tendons were operated with the Achilles scraping procedure alone, and for 55 Achilles operations also a plantaris tendon removal was performed. For 93% of the operated tendons, the patients were satisfied with the surgical outcome and the VAS had decreased from 74 preoperatively to 8 postoperatively. Nine male patients (9 tendons), five operated with scraping + plantaris removal, had remaining tendon pain during loading and were not satisfied. Their VAS score ranged from 22 to 91. For 21% of the operated tendons, some occasional mild discomfort not preventing from full tendon loading, was reported. There were no differences in pain reduction and satisfaction rates between men and women, and between Achilles scraping alone and scraping plus plantaris removal.

Conclusion:

Ultrasound and colour Doppler–guided surgical Achilles tendon scraping and plantaris tendon removal in patients with chronic painful midportion Achilles tendinopathy show remaining good clinical outcomes and high satisfaction rates in this longer-term follow-up.

Clinical presentation and surgical management of chronic Achilles tendon disorders - A retrospective observation on a set of consecutive patients being operated by the same orthopedic surgeon

BACKGROUND

Non-invasive treatment is not always successful in patients with Achilles tendon disorders, and surgical treatment is instituted as the next step. There is sparse knowledge about the diagnoses, pain levels before surgery, surgically confirmed pathologies and postoperative complications in large patient groups.

AIMS

To study the diagnoses, pain scores before surgery, macroscopic surgical findings and postoperative complications in a series of patients treated for Achilles disorders.

MATERIAL AND METHODS

One surgeon operated on 771 Achilles tendons of 481 men and 290 women during a 10-year period. The clinically and ultrasound confirmed diagnoses, pre-operative pain and functional scores (Visual Analogue Scale, VAS, range 0-100; Victorian Institute Sports Tendon Assessment - Achilles questionnaire, VISA-A), macroscopic findings during surgery and postoperative complications, were retrospectively collected from a database.

RESULTS

Clinically, by ultrasound and during surgery midportion Achilles tendinopathy was confirmed in 519 (67%) patients, 41% of them had a thickened plantaris tendon located close the Achilles tendon. Partial midportion rupture was found in 31 (4%) patients, chronic midportion rupture in 12 (2%) patients and insertional Achilles tendinopathy, including superficial and retro-calcaneal bursitis, Haglund deformity, distal Achilles tendinopathy, plantaris tendon pathology, and bone spurs, in 209 (27%) patients. The mean pre-operative pain scores for midportion Achilles tendinopathy were 73 (VAS) and 45 (VISA-A), and for insertional Achilles tendinopathy 77 (VAS) and 39 (VISA-A). For midportion Achilles tendinopathy there were 14 (3%), and for insertional Achilles tendinopathy 10 (5%), postoperative complications.

CONCLUSIONS

Patients presenting high pain scores from midportion Achilles tendinopathy were the most common. Plantaris tendon involvement is a frequent observation. For insertional Achilles tendinopathy the combination of pathology in the subcutaneous and retrocalcaneal bursa, a Haglund deformity and distal Achilles tendinopathy/tendinosis was most frequent.

SERIES STUDY, LEVEL OF EVIDENCE

4.

The Plantaris Muscle Tendon and Its Relationship with the Achilles Tendinopathy

Purpose

Although the plantaris muscle (PM) is vestigial in humans, it has a significant clinical role in procedures such as grafting. However, recent reports suggest its potential involvement in the tendinopathy of the midportion of the Achilles tendon. The aim of the study is therefore to evaluate morphological variation of the PM with regard to its potential conflict with the Achilles tendon.

Material and Methods

Classical anatomical dissection was performed on 130 lower limbs (71 right, 59 left) fixed in 10% formalin solution. The morphology of the PM was assessed regarding the relationship between the course of the plantaris tendon and the calcaneal tendon.

Results

The PM was present in 89.2% of cases. The findings indicate the presence of a new type of PM tendon insertion in which the tendon is inserted into the tarsal canal flexor retinaculum, potentially affecting the tendinopathy of the tibialis posterior muscle. In 26 cases (22.4%), insertion blended with the Achilles tendon (Type II), which may increase the risk of Achilles tendinopathy.

Conclusion

The anatomical variation of PM tendon morphology may create a potential conflict with the Achilles tendon and the tibialis posterior tendon, thus increasing the possibility of tendinopathy.

[Biomechanical study of different suture methods in repairing tendon rupture]

Objective

To evaluate the biomechanical property of tendons repaired with the modified Kessler suture combined with " 8" suture, and to provide evidence for the clinical application of this suture methods in repairing acute Achilles tendon rupture.

Methods

Forty frozen flexor digitorum longus tendons from fresh pork hind leg were randomly assigned into 4 groups, 10 specimens each group. In group A, the tendons were dissected transversely at the midpoint to forming the model of tendon with transversely cutting injury. The tendons in groups B, C, and D were dissected transversely at the midpoint, then a 2 cm segment of tendon from the incision in each side was dissected longitudinally with 1 mm internal to forming " frayed tendon" model. All the tendons were sutured with2-0 non-absorbable suture material with different suturing methods: in group A, the tendons with transversely cutting injury model with Krackow suture, and in the groups B, C, and D with Krackow suture, Kessler suture, and the modified Kessler suture combined with " 8" suture separately. All repaired tendons were fixed onto the biomechanical testing machine. The length, width, and thickness of each side and midpoint of the tendons were recorded, and the cross-sectional area was calculated. The tendons were stretched at a speed of 15 mm/minutes until failure (suture avulsion or rupture). The computer automatically recorded the maximum load, stress, strain, the failure displacement, and the stiffness. These biomechanical parameters of tendons in different groups were analyzed and compared.

Results

There was no significant difference in the length and cross-sectional area of each tendon among 4 groups ( F=0.245, P=0.863; F=0.094, P=0.963). Two tendons in group B, 1 in group C, and 1 in group D were excluded because of tendon slipping; all tendons in group A and 8 tendons in group B failured due to suture rupture, 9 tendons in group C due to suture slipping, and 9 tendons in group D due to 3 sutures slipping from tendon tissue together. The maximum load, the maximum stress, the maximum strain, the failure displacement, and the stiffness of the tendons between groups A and B showed no significant difference ( P>0.05). The maximum load, the maximum stress, and the stiffness of the tendons in group D were larger than those in both groups B and C ( P<0.05), but no significant difference was found in the maximum strain and the failure displacement between groups B, C, and D ( P>0.05). The maximum load, the maximum stress, the failure displacement, and the stiffness of the tendons in group B were larger than those in group C ( P<0.05), but the difference of maximum strain between groups B and C was not significant ( P>0.05).

Conclusion

The modified Kessler suture combined with " 8" suture can provide better biomechanical property of the repaired tendon compared with other suture approaches.

The effect of strain and age on the mechanical properties of rat Achilles tendons

BACKGROUND

Achilles tendon (AT) ruptures are common in the middle age population; however, the pathophysiology and influence of age on AT ruptures is not fully understood. This study evaluates the effect and interactions between, strain and age on the in vitro biomechanical properties of ATs.

METHODS

Bilateral ATs were harvested from 17 young (8 months) and 14 middle-aged (24 months) rats and underwent stress-relaxation using Fung's quasilinear viscoelastic (QLV) modeling and load-to-failure testing.

RESULTS

The initial viscoelastic response (parameter B) in middle-age animals was dependent on the amount of strain applied to the tendon and was significantly increased in middle-aged animals at higher strain. Higher strain in older animals led to a prolonged relaxation time (parameter tau 2). There was a trend toward an increased magnitude of the relaxation response (parameter C) at higher strain in the middle-aged animals. Middle-aged animals had a significantly lower mean stress at ultimate failure (p=0.01), while Young's modulus was similar in both groups (p=0.46).

CONCLUSIONS

The passive biomechanical properties of the rat AT change with age and the influence stress-relaxation response of the AT, thereby possibly predisposing the AT of older animals to fail at lower loads compared to younger animals.

LEVEL OF EVIDENCE

Not applicable, this is a basic science study.

Effect of High-Volume Injection, Platelet-Rich Plasma, and Sham Treatment in Chronic Midportion Achilles Tendinopathy: A Randomized Double-Blinded Prospective Study

BACKGROUND

Injection therapies are often considered alongside exercise for chronic midportion Achilles tendinopathy (AT), although evidence of their efficacy is sparse.

PURPOSE

To determine whether eccentric training in combination with high-volume injection (HVI) or platelet-rich plasma (PRP) injections improves outcomes in AT.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 60 men (age, 18-59 years) with chronic (>3 months) AT were included and followed for 6 months (n = 57). All participants performed eccentric training combined with either (1) one HVI (steroid, saline, and local anesthetic), (2) four PRP injections each 14 days apart, or (3) placebo (a few drops of saline under the skin). Randomization was stratified for age, function, and symptom severity (Victorian Institute of Sports Assessment-Achilles [VISA-A]). Outcomes included function and symptoms (VISA-A), self-reported tendon pain during activity (visual analog pain scale [VAS]), tendon thickness and intratendinous vascularity (ultrasonographic imaging and Doppler signal), and muscle function (heel-rise test). Outcomes were assessed at baseline and at 6, 12, and 24 weeks of follow-up.

RESULTS

VISA-A scores improved in all groups at all time points ( P < .05), with greater improvement in the HVI group (mean ± SEM, 6 weeks = 27 ± 3 points; 12 weeks = 29 ± 4 points) versus PRP (6 weeks = 14 ± 4; 12 weeks = 15 ± 3) and placebo (6 weeks = 10 ± 3; 12 weeks = 11 ± 3) at 6 and 12 weeks ( P < .01) and in the HVI (22 ± 5) and PRP (20 ± 5) groups versus placebo (9 ± 3) at 24 weeks ( P < .01). VAS scores improved in all groups at all time points ( P < .05), with greater decrease in HVI (6 weeks = 49 ± 4 mm; 12 weeks = 45 ± 6 mm; 24 weeks = 34 ± 6 mm) and PRP (6 weeks = 37 ± 7 mm; 12 weeks = 41 ± 7 mm; 24 weeks = 37 ± 6 mm) versus placebo (6 weeks = 23 ± 6 mm; 12 weeks = 30 ± 5 mm; 24 weeks = 18 ± 6 mm) at all time points ( P < .05) and in HVI versus PRP at 6 weeks ( P < .05). Tendon thickness showed a significant decrease only in HVI and PRP groups during the intervention, and this was greater in the HVI versus PRP and placebo groups at 6 and 12 weeks ( P < .05) and in the HVI and PRP groups versus the placebo group at 24 weeks ( P < .05). Muscle function improved in the entire cohort with no difference between the groups.

CONCLUSION

Treatment with HVI or PRP in combination with eccentric training in chronic AT seems more effective in reducing pain, improving activity level, and reducing tendon thickness and intratendinous vascularity than eccentric training alone. HVI may be more effective in improving outcomes of chronic AT than PRP in the short term. Registration: NCT02417987 ( ClinicalTrials.gov identifier).

Midsubstance Tendinopathy, Surgical Management

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

Imaging Techniques and Indications

This article evaluates the utility of radiography, ultrasonography, and MRI in diagnosing Achilles tendon injuries. It reviews the pertinent anatomy of the Achilles and associated structures, and signs of disorder with each imaging technique. The economics of use ultrasonography and MRI are discussed. They should serve as complementary diagnostic tools, with ultrasonography the first choice because of its ease of use, ability to view dynamic function, and cost. However, clinical examination is often best for diagnosis; MRI and ultrasonography often should be considered only when the diagnosis is confounding or a patient does not respond to recommended conservative care.

Elastic Characteristics of the Normal Achilles Tendon Assessed by Virtual Touch Imaging Quantification Shear Wave Elastography

OBJECTIVES

To assess the elastic properties of the normal Achilles tendon in different age groups by Virtual Touch imaging quantification (VTIQ; Siemens Medical Solutions, Malvern, PA) shear wave elastography.

METHODS

A total of 326 healthy volunteers older than 18 years were divided into different groups by sex and age. The thickness, shear wave velocity (SWV) in sagittal and axial sections, and anisotropic coefficient of the Achilles tendon in a state of relaxation were obtained by conventional sonography and Virtual Touch imaging quantification elastography. These parameters were compared in different age and sex groups, and their correlations with age were evaluated.

RESULTS

The thickness of the Achilles tendon in men and women increased gradually with age, and it was larger in men than in women in each age group (P < .05). The SWV of the tendon in the sagittal section decreased slightly with age, but the sagittal and axial SWVs and anisotropic coefficient had no significant differences among different age groups (P > .05), and they also had no significant differences between men and women within any group (P > .05). The SWVs in the sagittal and axial sections and anisotropic coefficient had no correlation with age. Intraclass correlation coefficients for sagittal and axial SWVs obtained by 2 independent observers were 0.923 and 0.870, respectively.

CONCLUSIONS

The thickness of the Achilles tendon increased gradually with age. We confirmed that tendinous elastographic anisotropy and the stiffness of the tendon had no significant correlation with age.

Open surgical treatment for chronic midportion Achilles tendinopathy: faster recovery with the soleus fibres transfer technique

PURPOSE

The study aimed to compare two methods of open surgical treatment for midportion Achilles tendinopathy in sportsmen. A novel technique consisting in transferring some soleus fibres into the degenerated tendon to improve its vascularization and longitudinal tenotomies are evaluated and compared.

METHODS

From 2006 to 2011, fifty-two competitive and noncompetitive athletes affected by midportion Achilles tendinopathy were surgically treated and prospectively evaluated at 6 months and at a final 4-year mean follow-up. Twenty patients had longitudinal tenotomies, and thirty-two had soleus fibres transfer. Clinical outcome was evaluated by the American Orthopaedic Foot and Ankle Society (AOFAS) score and the Victorian Institute of Sports Assessment-Achilles (VISA-A) score. Time to return to walk and to run and tendon thickening were also recorded.

RESULTS

Patients in the soleus transfer group had a higher increase in AOFAS and VISA-A score at 6 months and at the mean 4-year final follow-up (by 5.4 points, 95 % CI 2.9-7.9, p < 0.001 and by 5.7 points, 95 % CI 2.5-8.9, p = 0.001, for AOFAS and VISA, respectively). They also needed less time to return to run: 98.9 ± 17.4 days compared to 122.2 ± 26.3 days for the longitudinal tenotomies group (p = 0.0019). The soleus transfer group had a greater prevalence of tendon thickening (59.4 % compared to 30.0 % in the longitudinal tenotomies group, p = 0.037).

CONCLUSIONS

Open surgery for midportion Achilles tendinopathy is safe and effective in medium term. Despite similar outcomes in postoperative functional scores, soleus transfer allows a faster recovery but has a higher incidence of tendon thickening. These results should suggest the use of the soleus graft technique in high-level athletes.

LEVEL OF EVIDENCE

Prospective comparative study, Level II.

Low recurrence rate after mini surgery outside the tendon combined with short rehabilitation in patients with midportion Achilles tendinopathy

BACKGROUND

There is a general opinion that a structured and specific rehabilitation is needed after treatment of midportion Achilles tendinopathy to minimize recurrence of the condition. There is sparse knowledge about the recurrence rates in large patient materials after specific treatments for midportion Achilles tendinopathy.

AIM

This study aimed to investigate the recurrence rates in a large number of patients with chronic painful midportion Achilles tendinopathy that had been surgically treated with the ultrasound (US) and Doppler (DP)-guided mini-surgical scraping technique. Postoperatively, a relatively simple rehabilitation protocol, including a range of movement exercises and gradually increased walking and biking before allowing free activity, was used.

MATERIALS AND METHODS

From a database, information about the recurrence rates after US + DP-guided mini-surgical scraping, performed by a single surgeon on 519 tendons with US + DP-verified chronic painful midportion Achilles tendinopathy, was obtained.

RESULTS

Recurrence of painful midportion Achilles tendinopathy was found in 26 of 519 (5%) operated tendons, 13 from women and 13 from men. In 13 tendons, a close by located plantaris tendon was extirpated during the reoperation.

CONCLUSION

In this large material on patients treated with US + DP-guided mini-surgical scraping for midportion Achilles tendinopathy, there were few recurrences, although only a simple and nonspecific rehabilitation protocol was used.

Gtf2ird1-Dependent Mohawk Expression Regulates Mechanosensing Properties of the Tendon

Mechanoforces experienced by an organ are translated into biological information for cellular sensing and response. In mammals, the tendon connective tissue experiences and resists physical forces, with tendon-specific mesenchymal cells called tenocytes orchestrating extracellular matrix (ECM) turnover. We show that Mohawk (Mkx), a tendon-specific transcription factor, is essential in mechanoresponsive tenogenesis through regulation of its downstream ECM genes such as type I collagens and proteoglycans such as fibromodulin both in vivo and in vitro Wild-type (WT) mice demonstrated an increase in collagen fiber diameter and density in response to physical treadmill exercise, whereas in Mkx(-/-) mice, tendons failed to respond to the same mechanical stimulation. Furthermore, functional screening of the Mkx promoter region identified several upstream transcription factors that regulate Mkx In particular, general transcription factor II-I repeat domain-containing protein 1 (Gtf2ird1) that is expressed in the cytoplasm of unstressed tenocytes translocated into the nucleus upon mechanical stretching to activate the Mkx promoter through chromatin regulation. Here, we demonstrate that Gtf2ird1 is essential for Mkx transcription, while also linking mechanical forces to Mkx-mediated tendon homeostasis and regeneration.

Sonoelastography in the diagnosis of tendinopathies: an added value

BACKGROUND

sonoelastography helps in the detection of abnormalities not yet evident on B-mode exam.

METHODS

in this observational study, we report a collection of cases of symptomatic patients without alterations at ultrasound imaging but with evidence of pathological findings at sonoelastography. Patients, with clinical history suggestive for tendinopathies or surgically treated, and negative at the ultrasound exam, were submitted to sonoelastography. Out of 846, 632 patients with positive ultrasound exam were excluded. Sonoelastography was therefore performed in the remaining 214.

RESULTS

the examination was positive in 168 cases: 78 patients were affected with shoulder diseases, while elbow pathology was observed in 31 subjects; patellar, Achilles and plantar fascia disorders were reported in 19, 27, and 13 patients, respectively.

CONCLUSION

sonoelastography can reveal tendon abnormalities of clinical relevance in a high percentage of cases, where the ultrasound exam was negative, making the method a complementary tool to ultrasound evaluation.

Predictors of primary Achilles tendon ruptures

BACKGROUND

The Achilles tendon is the strongest tendon in the human body. The incidence of Achilles tendon ruptures appears to be increasing.

OBJECTIVES

The aim of this review was to systematically summarize predictors influencing Achilles tendon rupture (ATR) risk.

METHODS

A systematic literature search was performed of reported determinants influencing the ATR risk. Studies were eligible if there was: (i) description of determinants predicting ATR; (ii) an outcome defined as ATR; (iii) any study design with at least ten adults included with ATR; (iv) use of statistical tests regarding differences between patients with an ATR and healthy controls; (v) a full text article available; (vi) an article written in English, German or Dutch. Quality assessment was done using a standardized criteria set. Best-evidence synthesis was performed.

RESULTS

We included 31 studies, of which two (6.5%) were considered high-quality studies. Moderate evidence was found for increased ATR risk and decreased fibril size of Achilles tendon.

CONCLUSION

Based on the results of this systematic review there is moderate evidence that decreased tendon fibril size increases the ATR risk. There is limited evidence for many other factors, some of which are modifiable, such as increased body weight, oral corticosteroid use and quinolone use and living in an urban area, and therefore may be of interest in future studies. Furthermore, these results showed that more high-quality studies are needed for evaluating the determinants influencing the ATR risk.

Heavy Slow Resistance Versus Eccentric Training as Treatment for Achilles Tendinopathy: A Randomized Controlled Trial

BACKGROUND

Previous studies have shown that eccentric training has a positive effect on Achilles tendinopathy, but few randomized controlled trials have compared it with other loading-based treatment regimens.

PURPOSE

To evaluate the effectiveness of eccentric training (ECC) and heavy slow resistance training (HSR) among patients with midportion Achilles tendinopathy.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 58 patients with chronic (>3 months) midportion Achilles tendinopathy were randomized to ECC or HSR for 12 weeks. Function and symptoms (Victorian Institute of Sports Assessment-Achilles), tendon pain during activity (visual analog scale), tendon swelling, tendon neovascularization, and treatment satisfaction were assessed at 0 and 12 weeks and at the 52-week follow-up. Analyses were performed on an intention-to-treat basis.

RESULTS

Both groups showed significant (P < .0001) improvements in Victorian Institute of Sports Assessment-Achilles and visual analog scale from 0 to 12 weeks, and these improvements were maintained at the 52-week follow-up. Concomitant with the clinical improvement, there was a significant reduction in tendon thickness and neovascularization. None of these robust clinical and structural improvements differed between the ECC and HSR groups. However, patient satisfaction tended to be greater after 12 weeks with HSR (100%) than with ECC (80%; P = .052) but not after 52 weeks (HSR, 96%; ECC, 76%; P = .10), and the mean training session compliance rate was 78% in the ECC group and 92% in the HSR group, with a significant difference between groups (P < .005).

CONCLUSION

The results of this study show that both traditional ECC and HSR yield positive, equally good, lasting clinical results in patients with Achilles tendinopathy and that the latter tends to be associated with greater patient satisfaction after 12 weeks but not after 52 weeks.

Eccentric and Concentric Exercise of the Triceps Surae: An in Vivo Study of Dynamic Muscle and Tendon Biomechanical Parameters

Triceps surae eccentric exercise is more effective than concentric exercise for treating Achilles tendinopathy, however the mechanisms underpinning these effects are unclear. This study compared the biomechanical characteristics of eccentric and concentric exercises to identify differences in the tendon load response. Eleven healthy volunteers performed eccentric and concentric exercises on a force plate, with ultrasonography, motion tracking, and EMG applied to measure Achilles tendon force, lower limb movement, and leg muscle activation. Tendon length was ultrasonographically tracked and quantified using a novel algorithm. The Fourier transform of the ground reaction force was also calculated to investigate for tremor, or perturbations. Tendon stiffness and extension did not vary between exercise types (P= .43). However, tendon perturbations were significantly higher during eccentric than concentric exercises (25%–40% higher,P= .02). Furthermore, perturbations during eccentric exercises were found to be negatively correlated with the tendon stiffness (R2= .59). The particular efficacy of eccentric exercise does not appear to result from variation in tendon stiffness or extension within a given session. However, varied perturbation magnitude may have a role in mediating the observed clinical effects. This property is subject-specific, with the source and clinical timecourse of such perturbations requiring further research.

Achilles tendinitis in systemic lupus erythematosus: search for an associated inflammatory disease

OBJECTIVES

Except for traumatic and iatrogenic causes, Achilles tendinitis (AT) is mostly encountered in the context of inflammatory rheumatic diseases. This study aimed to describe AT in systemic lupus erythematosus (SLE).

PATIENTS AND METHODS

Among 158 SLE patients who fulfilled the SLE criteria of the ACR classification followed between 1980 and 2013, we selected those who experienced at least one episode of AT not caused by traumatic or toxicity factors.

RESULTS

Eight patients (one male, seven females), median age 52 years (range: 35-68), presented with 11 episodes of AT within an average of 10.5 (0-21) years after SLE diagnosis. Clinical presentation of SLE was mainly cutaneous (eight of eight), and articular (seven of eight). Axial symptoms were reported in six patients, two of whom had HLA-B27-positive status, and fulfilled the Amor and European Spondylarthropathy Study Group criteria. Resolution of AT was good with nonsteroidal anti-inflammatory topical or systemic drug therapies, which kept SLE quiescent and avoided any increase of specific treatment.

CONCLUSION

Although the association is rare, when AT occurs in SLE patients, physicians should look for associated spondylarthritis.

Knotted versus knotless suture bridge repair of the achilles tendon insertion: a biomechanical study

BACKGROUND

Surgical treatment of insertional Achilles tendinopathy often involves detachment and debridement of the Achilles tendon insertion. A recent study has shown that knotted suture bridge fixation of the Achilles to the calcaneus is biomechanically superior to single-row fixation, but there is an absence of literature on the use of different suture bridge constructs to repair the Achilles tendon.

HYPOTHESIS

There will be no significant difference in the load to failure, mode of failure, tendon strain, tendon stiffness, repair site gapping, or footprint size when comparing knotted suture bridge repair to knotless suture bridge repair of the Achilles tendon after detachment for insertional Achilles tendinopathy.

STUDY DESIGN

Controlled laboratory study.

METHODS

A single specimen from each pair of 10 cadaveric Achilles tendons was randomized to 1 of 2 Achilles insertion repair groups: knotted (n = 10) or knotless (n = 10) suture bridge repair. Repaired footprint size was measured, and then cyclic testing from 10 to 100 N for 2000 cycles was performed. This was followed by measurement of tendon strain, repair site displacement, load to failure, and tendon stiffness.

RESULTS

The knotted suture bridge repair had a significantly higher load to failure compared with the knotless suture bridge (mean ± SD, 317.8 ± 93.6 N vs 196.1 ± 12.1 N, respectively; P = .001). All constructs failed at the tendon-suture interface. Tendon strain after cyclic testing was significantly greater in the knotless (1.20 ± 1.05) compared with the knotted (0.39 ± 0.4) suture repair groups (P = .011). There was no significant difference in footprint size between the knotted (230.3 ± 63.3 mm(2)) and knotless (248.5 ± 48.8 mm(2)) groups (P = .40). There was also no significant difference in stiffness (knotted = 76.4 ± 8.0 N/mm; knotless = 69.6 ± 10.9 N/mm; P = .17) and repair site displacement after cyclic testing (knotted = 2.8 ± 1.2 mm; knotless = 3.6 ± 1.1 mm; P = .17).

CONCLUSION

During suture bridge repair of the Achilles tendon after detachment, knots at the proximal suture anchors significantly improve the biomechanical strength of the repair.

CLINICAL RELEVANCE

This study demonstrated that the knotless suture bridge repair had a significantly lower load to failure than the knotted suture bridge. Surgeons should be aware of these biomechanical differences, as they influence the postoperative rehabilitation protocol and may lead to higher surgical complication rates.

In vivo evaluation of the elastic anisotropy of the human Achilles tendon using shear wave dispersion analysis

Non-invasive evaluation of the Achilles tendon elastic properties may enhance diagnosis of tendon injury and the assessment of recovery treatments. Shear wave elastography has shown to be a powerful tool to estimate tissue mechanical properties. However, its applicability to quantitatively evaluate tendon stiffness is limited by the understanding of the physics on the shear wave propagation in such a complex medium. First, tendon tissue is transverse isotropic. Second, tendons are characterized by a marked stiffness in the 400 to 1300 kPa range (i.e. fast shear waves). Hence, the shear wavelengths are greater than the tendon thickness leading to guided wave propagation. Thus, to better understand shear wave propagation in tendons and consequently to properly estimate its mechanical properties, a dispersion analysis is required. In this study, shear wave velocity dispersion was measured in vivo in ten Achilles tendons parallel and perpendicular to the tendon fibre orientation. By modelling the tendon as a transverse isotropic viscoelastic plate immersed in fluid it was possible to fully describe the experimental data (deviation<1.4%). We show that parallel to fibres the shear wave velocity dispersion is not influenced by viscosity, while it is perpendicularly to fibres. Elasticity (found to be in the range from 473 to 1537 kPa) and viscosity (found to be in the range from 1.7 to 4 Pa.s) values were retrieved from the model in good agreement with reported results.