Achilles tendinopathy-do plantaris tendon removal and Achilles tendon scraping improve tendon structure? A prospective study using ultrasound tissue characterisation

Tendon structure, clinical tests, and pain during-loading in young female competitive gymnasts

To examine the relationship between Achilles-tendon (AT) and patellar-tendon (PT) structure, clinical-examination and tendon pain in young gymnasts; and, to explore the associations between these factors and age, maturation, and training-load. Two hundred and seventy-four female gymnasts (aged 12.1±1.9 yrs) were assessed for anthropometric measures, pubertal-stage, and training-load. They had clinical-tests (pain-on-palpation for AT and pain-on-palpation and Royal-London Hospital-Test for PT), were asked about tendon-pain during-loading and were assessed for tendon-structure. Gymnasts with positive clinical-tests (with and without pain during-loading) presented a significantly higher prevalence of disorganized AT and PT compared to gymnasts with negative clinical-tests (with and without pain during-loading) (p<0.05). A significant pubertyXpositive clinical-test interaction was found for disorganized PT structure, whereby a disorganized structure was more prevalent among post-pubertal gymnasts with positive clinical-tests compared to pre-pubertal participants with negative clinical-tests (F(1, 263)=9.436, p=0.002). In gymnasts with positive clinical-tests, significant correlations were found between disorganized AT and PT structures and age, and training-load (p<0.05). An increased prevalence of disorganized tendon structure (regardless of pain during-loading) was seen in participants with positive clinical-tests. This disorganized tendon-structure was found to be significantly related to increased age, post-pubertal stage, and higher training hours in gymnasts with positive clinical-tests.

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.

Tendinopathic Plantaris but Normal Achilles Tendon Found in About One-Fifth of Patients Not Responding to Conservative Achilles Tendon Management - Results from a Prospective WALANT Surgical Case Series on 105 Tendons

Purpose

Midportion Achilles tendinopathy is a relatively common condition. This study aimed to investigate the presence of a normal Achilles tendon, but a tendinopathic plantaris tendon, in a large and consecutive prospective sample of patients referred to a specialised tendon clinic for midportion Achilles tendon pain not responding to non-surgical treatment.

Patients and Methods

A total of 105 consecutive tendons were operated on in 81 patients (62 males) suffering from painful midportion Achilles tendon pain. Clinical examination, ultrasound (US) and colour Doppler (CD) examination, and wide awake local anaesthetic no tourniquet (WALANT) surgery were performed in all patients.

Results

For 19/105 (18%) tendons from 14 patients, clinical examination suspected plantaris tendinopathy alone as there was a distinct tenderness on the medial side, but no thickening of the Achilles tendon. US examination followed by surgery confirmed the diagnosis.

Conclusion

Midportion Achilles tendon pain is not always related to Achilles tendinopathy since pain related to the plantaris tendon alone was found in almost every fifth patient. Consequently, there is an obvious need for proper examination to identify the pain source and establish a correct diagnosis before treatment.

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.

Ultrasound Measurement of Local Deformation in the Human Free Achilles Tendon Produced by Dynamic Muscle-Induced Loading: A Systematic Review

Achilles tendinopathy is the most prevalent lower limb tendinopathy, yet it remains poorly understood, with mismatches between observed structure and reported function. Recent studies have hypothesised that Achilles tendon (AT) healthy function is associated with variable deformation across the tendon width during use, focusing on quantifying sub-tendon deformation. Here, the aim of this work was to synthesise recent advances exploring human free AT tissue-level deformation during use. Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, PubMed, Embase, Scopus and Web of Science were systematically searched. Study quality and risk of bias were assessed. Thirteen articles were retained, yielding data on free AT deformation patterns. Seven were categorised as high-quality and six as medium-quality studies. Evidence consistently reports that healthy and young tendons deform non-uniformly, with the deeper layer displacing 18%-80% more than the superficial layer. Non-uniformity decreased by 12%-85% with increasing age and by 42%-91% in the presence of injury. There is limited evidence of large effect that AT deformation patterns during dynamic loading are non-uniform and may act as a biomarker of tendon health, risk of injury and rehabilitation impact. Better considered participant recruitment and improved measurement procedures would particularly improve study quality, to explore links between tendon structure, function, aging and disease in distinct populations.

Morphological variations of the calcaneal tendon: clinical significance

The calcaneal tendon, the largest and strongest in the human body, is created by the common junction of tendons of the gastrocnemius and soleus muscles. It is not a homogenous structure, being represented by layers in various arrangements. Morphological variability can be seen in the connection between the aponeurosis of the gastrocnemius muscle and the soleus muscle. Some types of plantaris tendon can be associated with a higher possibility of Achilles tendinopathy. Moreover, the presence of accessory structures, such as an accessory soleus muscle or additional gastrocnemius muscle heads may result in symptomatic pathologies. The main aim of this review is to summarize the current state of knowledge regarding the calcaneal tendon. Another aim is to present morphological variations of the calcaneal tendon and their clinical significance. Such information may be useful for clinicians, especially orthopedists, and surgeons. This review also provides an overview of embryological development and morphological variation among fetuses. Materials and methods: review was conducted according to PRISMA guidelines. An electronic search was conducted in five databases. Top quality tools were used to assess the quality of evidence in the studies reviewed. Research papers that made up the database of this review were analyzed, selected and assessed by two independently working researchers.

Achilles Tendon and Patellar Tendon Structure in Combat Soldiers Following Prevention Exercises

INTRODUCTION

Military training that increases physical stress on musculoskeletal morphology also increases the risk of orthopedic injuries. Somatosensory prevention programs that reduce stress and improve functionality could be beneficial for better organization of tendon structure. The aim of this study was to investigate the impact of a somatosensory prevention exercise on the tendon structure (percentage of echo-type fibers; A-P and M-L diameters and cross-sectional area) of the Achilles tendon and patellar tendon among combat soldiers.

MATERIALS AND METHODS

These tendons of male Infantry soldiers aged 18-21 were screened before and after a 14-week training course. The intervention group, who performed preventative exercises, included 108 soldiers (BMI = 23.85 ± 2.76), while the control group, who participated in the same military course without these exercises, included 98 soldiers (BMI = 24.26 ± 4.03). Ultrasound scanning for tendon structure included percent of echo-type I-IV fibers, A-P diameter, M-L diameter, and cross-sectional area parameters.

RESULTS

Time by group interaction was found for echo-type I and II in both tendons. No significant differences were found between the two groups in the pretesting percentage of echo-type IV fibers of the Achilles tendon (P = .522), in echo-type III fibers of the Achilles tendon (P = .833), and echo-type IV fibers of the patellar tendon (P = .162). Greater pre-post differences in echo-type III and IV fibers were found in the control group compared with the intervention group for both the Achilles tendon (P = .021, P = .002) and the patellar tendon (P < .001, P < .001).

CONCLUSION

Increased damaged fibers (echo-type III and IV) of both tendons were found among the control group, yet not among soldiers who performed prevention exercises.

Achilles and patellar tendon structure following a prevention program in male combat soldiers

OBJECTIVES

The aims of the study were to compare the prevalence of soldiers with musculoskeletal symptoms between soldiers that participated in a prevention program (INT) and a control group (CONT); and, to assess whether 'high risk' for a symptom indicator [participants with patellar tendon (PT) echo-type III+IV >10% or Achilles tendon (AT) echo-type III >8.5%] applies when a prevention intervention is used.

METHODS

Soldiers from two consecutive infantry commanders courses (year 1-CONT, n = 165; year 2-INT, n = 196) were examined pre-course for AT and PT structure using ultrasound tissue characterization (UTC), and their musculoskeletal overuse symptoms were assessed and recorded by military physicians throughout the course. A prevention program was provided to the INT group (year 2) during the 14-week course.

RESULTS

No significant differences were found in the prevalence of soldiers with symptoms between the two groups [INT: 39 (19.9%), CONT: 40 (24.2%); p = .32]. Using the indicator at baseline, 20 soldiers (10.2%) were suggested to be at 'high risk.' Of those 20 soldiers, 17 actually had symptoms during the course (positive predictive value-85%). The prevalence of soldiers with a suggested 'high risk' according to our indicator who had no symptoms during the course was low (3/20, 15%). Twenty-two soldiers who had symptoms during the course had not been suggested to be at 'high risk' by our indicator.

CONCLUSION

Our intervention did not reduce the prevalence of soldiers with symptoms. Our 'high risk' pre-course, AT and PT structure indicator is valid and can be used as a screening tool to reduce the prevalence of symptoms in combat soldiers; with the caution that soldiers that were not identified by the indicator, might also have symptoms along the course.

Intra- and Inter-Rater Reliability of Processing Ultrasound Tissue Characterization Scans in Midportion Achilles Tendinopathy

Purpose

Ultrasound tissue characterization (UTC) is used to visualize and quantify the Achilles tendon structure. We investigated the intra-rater and inter-rater reliability of UTC for quantifying the midportion tendon structure and the area of maximum degeneration (AoMD) in military personnel with midportion Achilles tendinopathy.

Method

UTC scans of 50 patients (16-60 years) were processed twice by rater 1 and once by rater 2. First, the midportion tendon structure was quantified and subsequently the AoMD. The intraclass correlation coefficient (ICC) was calculated for echo-types I, II, III, IV, aligned fibrillar structure (echo-types I + II), and disorganized tendon structure (echo-types III + IV).

Results

For midportion tendon structure, all ICC values were excellent for intra-rater reliability (range: 0.97 to 0.99) and inter-rater reliability (range: 0.98 to 0.99). Regarding the AoMD, intra-rater reliability showed excellent ICC values for all echo-types (range: 0.94 to 0.98) except for echo-type II (0.85). Inter-rater reliability showed excellent ICC values for all echo-types (range: 0.92 to 0.98).

Conclusion

Processing of UTC scans is highly reliable in quantifying the midportion Achilles tendon structure and the AoMD.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level IV.

Sharp pain in a normal Achilles tendon of a professional female football player was related to a plantaris tendon in a rare position: a case report

BACKGROUND

Plantaris tendinopathy and plantaris-associated Achilles tendinopathy can be responsible for chronic pain in the Achilles tendon midportion, often accompanied by medial tenderness. As conservative treatments are less successful for this patient group, proper diagnosis is important for decision making. This report presents a case with plantaris tendinopathy in a rare (superficial) location.

CASE PRESENTATION

This article describes a pain history and treatment timeline of a professional Swedish female soccer player (32 years old, Northern European ethnicity, white) who suffered from sharp pain in the Achilles tendon midportion and tenderness on the medial and superficial side for about 2 years. Conservative treatments, including eccentric exercises, were not successful and, to some extent, even caused additional irritation in that region. Ultrasound showed a wide and thick plantaris tendon located on the superficial side of the Achilles tendon midportion. The patient was surgically treated with local removal of the plantaris tendon. After surgery there was a relatively quick (4-6 weeks) rehabilitation, with immediate weight bearing, gradual increased loading, and return to running activities after 4 weeks. At follow-up at 8 weeks, the patient was running and had not experienced any further episodes of sharp pain during change of direction or sprinting.

CONCLUSIONS

The plantaris tendon should be considered as a possible source of Achilles tendon pain. This case study demonstrates that the plantaris tendon can be found in unexpected (superficial) positions and needs to be carefully visualized during clinical and imaging examinations.

Achilles Scraping and Plantaris Tendon Removal Improves Pain and Tendon Structure in Patients with Mid-Portion Achilles Tendinopathy-A 24 Month Follow-Up Case Series

Background: Studies have demonstrated that a sub-group of patients with medial Achilles pain exhibit Achilles tendinopathy with plantaris tendon involvement. This clinical condition is characterised by structural relationships and functional interference between the two tendons, resulting in compressive or shearing forces. Surgical plantaris tendon removal together with an Achilles scraping procedure has demonstrated positive short-term clinical results. The aim of this case series was to determine the long-term outcomes on pain and Achilles tendon structure. Methods: 18 consecutive patients (13 males; 5 females; mean age 39 years; mean symptom duration 28 months), of which three were elites, were included. Clinical examination, b-mode ultrasound (US) and Ultrasound Tissue Characterisation (UTC) confirmed medial Achilles tendon pain and tenderness, medial Achilles tendinopathy plus a plantaris tendon located close to the medial side of the Achilles tendon. Patients underwent US-guided local Achilles scraping and plantaris tendon removal followed by a structured rehabilitation program. Outcomes were VISA-A score for pain and function and UTC for Achilles structure. Results: 16 of 18 patients completed the 24 months follow-up. Mean VISA-A scores increased from 58.2 (±15.9) to 92.0 (±9.2) (mean difference = 33.8, 95% CI 25.2, 42.8, p < 0.01). There was an improvement in Achilles structure with mean organised echo pixels (UTC type I+II, in %) increasing from 79.9 (±11.5) to 86.4 (±10.0) (mean difference = 6.5%, 95% CI 0.80, 13.80, p =0.01), exceeding the 3.4% minimum detectable change. All 16 patients reported satisfaction with the procedure and 14 returned to pre-injury activity levels. There were no reported complications. Conclusions: Improved pain, function and tendon structure were observed 24 months after treatment with Achilles scraping and plantaris excision. The improvement in structure on the medial side of the Achilles after plantaris removal indicates that compression from the plantaris tendon might be an important presenting factor in this sub-group.

Substantiating the Use of Ultrasound Tissue Characterization in the Analysis of Tendon Structure: A Systematic Review

OBJECTIVE

To determine the role of ultrasound tissue characterization (UTC) in predicting, diagnosing, and monitoring tendon structure and/or tendinopathy. In addition, this study aims to provide recommendations for standardized methodology of UTC administration and analysis.

DATA SOURCE

The PubMed, Embase, and Web of Science databases were searched (up to September 2018). All scientific literature concerning the use of UTC in assessing tendons was collected. The initial search resulted in a total of 1972 hits, and after screening by eligibility criteria, 27 articles were included.

RESULTS

In total, 18 investigating the Achilles tendon, 5 the patellar tendon, and 4 both Achilles and patellar tendons were included. The methods of UTC administration and analysis differed and were not uniform. The studies showed that the use of UTC to predict Achilles tendinopathy (AT) is inconclusive, but that a higher amount of tendon disorganization increases the risk of developing patellar tendinopathy (PT). In terms of diagnosis, UTC might provide additional information in AT cases. In addition, promising results were found for the use of UTC in both AT and PT in monitoring the effect of load or treatment on tendon structure.

CONCLUSION

More research regarding the use of UTC in predicting tendon pathology is required. Ultrasound tissue characterization seems useful as an adjunct diagnostic modality because it can be used to differentiate symptomatic from asymptomatic tendons. In addition, UTC is a promising device to be used to monitor changes in tendon structure in response to load or treatment. Moreover, we provide recommendations of a standardized protocol concerning the methods of UTC measurement and analysis.

Multimodal Ultrasound Versus MRI for the Diagnosis and Monitoring of Achilles Tendinopathy: A Prospective Longitudinal Study

Background:

The diagnosis and monitoring of Achilles tendinopathy with imaging are challenging. There is a lack of studies comparing the diagnostic accuracy of magnetic resonance imaging (MRI), brightness mode ultrasound (B-mode), and power Doppler ultrasound with recent technologies such as ultrasound tissue characterization (UTC) and shear wave elastography (SWE).

Purpose:

To assess whether SWE and UTC, which offer quantitative values, show a superior diagnostic accuracy and capacity to detect structural improvement in Achilles tendinopathy compared with MRI, B-mode, or power Doppler.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

Patients with insertional (n = 28) and midportion (n = 38) Achilles tendinopathy were evaluated at baseline and 6-month follow-up using MRI, B-mode, power Doppler, SWE, and UTC. Asymptomatic controls (n = 37) were evaluated at T₀. Diagnostic accuracy was analyzed based on a quantitative receiver operating characteristic (ROC) analysis with quantitative cutoff values (anteroposterior diameter, Öhberg score, UTC echo type, Young modulus) and by semiquantitative Likert scale–based assessment of experienced physicians.

Results:

For diagnosing insertional Achilles tendinopathy, semiquantitative MRI and power Doppler were most favorable (diagnostic accuracy, 95%), while the cross-sectional area of MRI revealed 89% accuracy in the ROC analyses (area under the curve [AUC], 0.911; P < .001). For diagnosing midportion Achilles tendinopathy, semiquantitative MRI and B-mode were most favorable (diagnostic accuracy, 87%), while UTC echo types 3 and 4 revealed 86% and 87% accuracy, respectively, in the ROC analyses (AUC, 0.911 and 0.941, respectively; P < .001). However, for quantitative and semiquantitative evaluation of diagnostic accuracy in both insertional and midportion Achilles tendinopathy, there was no significant difference in favor of one imaging modality over the others. Compared with baseline, only SWE showed a significant change at the 6-month follow-up (P = .003-.035), but there were only fair to poor monitoring accuracies of 71% (insertion) and 60% (midportion). However, compared with the other modalities, the monitoring accuracy of SWE was significantly higher (P = .002-.039).

Conclusion:

There was no statistically significant difference in favor of one imaging modality over the others, but MRI revealed the highest overall diagnostic accuracy for the diagnosis of both insertional and midportion Achilles tendinopathy.

Ultrasound and surgical inspection of plantaris tendon involvement in chronic painful insertional Achilles tendinopathy: a case series

Objectives

Chronic painful insertional Achilles tendinopathy is known to be difficult to manage. The diagnosis is not always easy because multiple different tissues can be involved. The plantaris tendon has recently been described to frequently be involved in chronic painful mid-portion Achilles tendinopathy. This study aimed to evaluate possible plantaris tendon involvement in patients with chronic painful insertional Achilles tendinopathy.

Methods

Ninety-nine consecutive patients (74 males, 25 females) with a mean age of 40 years (range 24–64) who were surgically treated for insertional Achilles tendinopathy, were included. Clinical examination, ultrasound (US)+Doppler examination, and surgical findings were used to evaluate plantaris tendon involvement.

Results

In 48/99 patients, there were clinical symptoms of plantaris tendon involvement with pain and tenderness located medially at the Achilles tendon insertion. In all these cases, surgical findings showed a thick and wide plantaris tendon together with a richly vascularised fatty infiltration between the plantaris and Achilles tendon. US examination suspected plantaris involvement in 32/48 patients.

Conclusion

Plantaris tendon involvement can potentially be part of the pathology in chronic painful insertional Achilles tendinopathy and should be considered for diagnosis and treatment when there is distinct and focal medial pain and tenderness.

Level of evidence

IV case series.

The Influence of a 14-Week Infantry Commanders Courses on the Achilles Tendon and Patellar Tendon Structure

INTRODUCTION

Alternated tendon structure may raise stress to the musculoskeletal structures and may increase the potential for overuse injury. Screening the tendon structure of soldiers pre- and post-participation in a strenuous combat course is essential. The aim of the present study was to investigate the influence of a 14-week infantry commanders courses on the Achilles tendon (AT) structure and patellar tendon (PT) structure in combat soldiers.

MATERIALS AND METHODS

Ninety-eight participants from an infantry commanders course were screened pre- and post-course for the AT and PT structures, using ultrasonographic tissue characterizaton (UTC) imaging to capture a 3D structure of four echo-type fibers (I-IV).

RESULTS

In both tendons, the mean relative frequency of echo-type I fibers significantly decreased from pre- to post-testing, with a significant increase in the relative frequency of echo-types II, III, and IV fibers. In the AT, 60.2% of the subjects showed positive differences (between pre- and post-testing in the echo-type III + IV fiber ("worsened" tendon structure), whereas in the PT, 92.2% of the subject showed an increased frequency. No significant correlation (r = 0.108; P = .324) was found between the differences of echo-type III + IV fibers of the AT and that of the PT.

CONCLUSIONS

Loads to the musculoskeletal structures along the combat course increased the mean relative frequency of the "reduced" echo-type fibers (III + IV) in both the AT structure and the PT structure. Yet, whereas in the AT around 40% of the soldiers showed an improved tendon structure along the course, in the PT less than 10% of the soldiers showed that improvement. Soldiers and commanders should be aware of the different influence of the loading exercises along the course on the AT and on the PT structure, as "reduced" tendons structure might put the soldiers at higher risk for injury in the future.

The influence of a multidisciplinary intervention program on Achilles tendon structure in children with overweight and obesity

The effects of childhood obesity on tendon structure and its relation to physical activity are barely known. We aimed to investigate the influence of a 6-month multidisciplinary childhood obesity management program (which included dietary intervention and an exercise program) on Achilles tendon structure in overweight/obese children. Twenty-five overweight/obese children (overweight group) who participated in a 6-month multidisciplinary childhood obesity program, and 27 normal-weight controls were examined for anthropometric measurements and for Achilles tendon structure (using ultrasound tissue characterization to capture a three-dimensional structure of four echo type fibers and the cross-sectional area) at baseline, 3, and 6 months. The BMI of the overweight group significantly decreased from the pre- to the post-intervention period, (p = .002, η² = .229), yet among the control group, the BMI significantly increased (p = .002, η² = .222). Interactions (pre-post × group) showed a significant decrease in the prevalence of echo type I and in echo type III fibers and a significant increase in the prevalence of echo type II fibers and in the cross-sectional area along the intervention. No significant changes in echo type fibers were found in the control group along the 6 months.Conclusion: At pre-intervention, the overweight group had significantly "worse" tendon structure, with a lower prevalence of echo type II fiber and a higher prevalence of echo type III fibers compared with the control group. Following the 6-month intervention, the tendon structure of the overweight group was "positively" changed, with reduced echo type III fibers and increased echo type II fibers. What is Known: • Physical activity and weight reduction programs are efficient for obese children. • Obese children tend to suffer orthopedic problems and pain during physical activity. What is New: • Pre-intervention, obese children had 'worse' tendon structure compared to controls. • Following 6-month program, tendon structure of obese children 'positively' changed.

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

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

Can Achilles and patellar tendon structures predict musculoskeletal injuries in combat soldiers?

Aiming to investigate whether Achilles tendon (AT) structure and patellar tendon (PT) structure are risk factors for musculoskeletal injuries in combat soldiers, 168 participants were recruited from an infantry commander's course. The AT and PT were examined pre-course using UTC to capture the structure of four echo-type fibers (I-IV). All injuries were assessed by military physicians pre-course and throughout the 14-week course. Soldiers who were injured during the course had a significantly higher pre-course prevalence of AT and PT echo-type III and echo-type IV compared to soldiers that were not injured during the course. Variables that were found to be associated with injured/non-injured participants were echo-type III + IV of the PT (OR = 1.44, 95% CI = 1.24-1.68) and echo-type III of the AT (OR = 1.69, 95% CI = 1.35-2.12). ROC analyses showed that the best model, exhibiting both high sensitivity and low specificity, was that participants with PT echo-type III + IV > 10% or AT echo-type III >8.5% had the highest risk of being injured during the course. In conclusions, the tendon structure at the beginning of high-intensity activity or physical training program might be a risk factor for subsequent injury during the course. Soldiers and high-level athletes should be aware of the cutoff points for fiber types in tendon structure that might put them at high risk for future injury. At-risk soldiers/athletes should be provided with an intervention program before they start their training program, with the aim of improving the tendon structure and preventing subsequent injury.

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.

Differences Between Long Distance Road Runners and Trail Runners in Achilles Tendon Structure and Jumping and Balance Performance

BACKGROUND

Load and joint kinematics change with differences in running surface. Running regularly on trails compared to roads might influence the load on the Achilles tendon and its adaptations, along with other factors such as balance, strength, and proprioception.

OBJECTIVE

To investigate Achilles tendon structure and functional tests in road and trail runners.

DESIGN

Cross-sectional study.

SETTING

Laboratory, sport sciences college.

PARTICIPANTS

The study included 26 road and 17 trail runners who run at least three times per week with a minimum of 20 km per week and who participated in running competitions over the preceding 2 years.

METHODS

Each participant was examined for Achilles tendon structure (via ultrasound tissue characterization [UTC] imaging) and underwent functional tests in addition to completing a demographic questionnaire.

MAIN OUTCOME MEASUREMENTS

The percentages of echo types I, II, III, and IV (degree of structural homogeneity) within the tendon, tendon length and width, tendon cross-sectional area (via UTC imaging); Ankle inversion movement discrimination ability (via Active Movement Extent Discrimination Apparatus device); dynamic postural balance (via Y balance test); jumping performance (by Triple hop distance test); and Hip muscle abduction muscle strength (by hand-held dynamometry).

RESULTS

Percentage of echo type I was significantly lower while echo type II was higher in the road group compared with the trail group (67.3% type I and 28.9% type II in the road group compared with 74.1% type I and 22.1% type II in the trail group, P < .001). No differences between genders were found and no significant differences between groups were found for the other tests.

CONCLUSION

Tendon integrity as examined with UTC is different between road and trail runners. This suggests an influence of running surface on Achilles tendon structure. This difference was not reflected in other tests, thus the influence of tendon structure on function needs further examination.

Achilles Tendon Tissue Structure in Children with Overweight and Children with Obesity

Aim: To investigate differences in Achilles tendon structure between children with overweight/obesity and children with normal weight.Methods: Twenty-two children with obesity, 10 children with overweight, and 44 children with normal weight participated in the study. BMI% was calculated. The Achilles tendon was examined using ultrasound tissue characterization (UTC) imaging to capture a three-dimensional structure of four echo-type fibers and a cross-sectional area.Results: A significantly higher percentile of echo-types II, a lower percentile of echo-types III and IV, and a lower cross-sectional area were found for children with normal weight compared with children with overweight/obesity (p < .05). Following a piecewise linear regression model according to tendon structure, a BMI percentile of 75% was found to be the most accurate cutoff point of the children into the "unaffected" (BMI% <75%) and "affected" tendon structure groups (BMI% ≥ 75%), as the children with BMI%≥75% already had an Achilles tendon structure similar to that of the children with overweight/obesity.Conclusions: Tendon integrity as examined with UTC differs between children with obesity and children with normal weight. Children with a BMI percentile of ≥75 already demonstrate a different tendon structure pattern compared with children with BMI percentile of <75. This may put children with obesity at a greater risk of injury and should be addressed when applying an exercise program for children with overweight/obesity.

Ankle Joint Position and the Reliability of Ultrasound Tissue Characterization of the Achilles Tendon: A Pilot Study

Background

Imaging of the Achilles tendon using ultrasound tissue characterization (UTC) involves taking up the slack of the tendon by including dorsiflexion of the ankle. This pilot study aimed to determine whether different longitudinal tension applied to the Achilles tendon during imaging affected the reliability of UTC.

Material/Methods

Nine asymptomatic active volunteers, aged between 23–49 years underwent imaging of 17 Achilles tendons. Three positions of tension included plantar grade, 50%, and 100% of maximal dorsiflexion, with a range of 18–32°. Ranges were established and standardized using an isokinetic dynamometer. A test and re-test process was conducted at each position to determine the intraclass correlation coefficients (ICCs) and minimum detectable change (MDC) per echotype. Images were analyzed using UTC software.

Results

Plantar grade positioning images could not be obtained. ICCs for each echotype I–IV between test 1 and test 2 were 0.965, 0.962, 0.858, 0.739 at 100% dorsiflexion (95% CI, 0.86–0.99, 0.84–0.99, 0.51–0.97, and 0.2–0.94), and 0.771, 0.551, 0.569, 0.429 at 50% dorsiflexion (95% CI, 0.29–0.94, −0.09–0.88, −0.01–0.88, and −0.15–0.82). The MDC per echotype I–IV ranged between 4.1–1.0% of echotype data at 100% dorsiflexion, and 17.2–6.3% at 50% dorsiflexion.

Conclusions

Testing at maximum dorsiflexion provided improved reliability when using UTC in healthy individuals. The ICC at 100% dorsiflexion was increased, and the MDC was reduced for all echotypes. Therefore, standardizing test positions when using UTC is advisable for reliable comparison of results between studies.

Minimally Invasive and Endoscopic Approach for the Treatment of Noninsertional Achilles Tendinopathy

Minimally invasive treatment can offer an earlier recovery with less pain and scarring compared with traditional open surgeries. The goals of minimally invasive surgery are to debride degenerative tendon, stimulate healing, and, when appropriate, repair damaged tendon. Sclerotherapy and prolotherapy have been shown to reduce neovascularization and pain. Percutaneous stripping and endoscopic debridement are better options for diffuse tendinopathy. Plantaris release can be useful in diffuse disease in patients with primarily medial-sided Achilles pain. Overall, minimally invasive surgery provides similar benefits as open procedures with reduced complications and morbidity.

Prevalence of Coexistent Plantaris Tendon Pathology in Patients with Mid-Portion Achilles Pathology: A Retrospective MRI Study

Co-existence of Plantaris tendinopathy (PT) in patients with mid-Achilles tendinopathy (Mid-AT) is of clinical significance. This study aims to describe the MRI-based pathological characteristics of co-existing PT and Mid-AT. One-hundred MRI studies of patients diagnosed with Mid-AT were retrospectively analysed by an experienced musculoskeletal radiologist. Presence or absence of a Plantaris tendon, co-existing PT with Mid-AT, insertional characteristics of Plantaris tendon, and maximum anteroposterior thickness of the tendon in Mid-AT (axial images) were evaluated. When PT co-existed with Mid-AT, the location of the tendon pathologies in relation to calcaneal insertion was assessed (sagittal images) and their association was analysed using the coefficient of variation (CV) and Pearson’s correlation coefficient. Plantaris was present in 84 cases (84%), and Mid-AT and PT co-existed in 10 cases (10%). A greater variability in the location of Plantaris pathology (CV = 42%) than Achilles tendinopathy (CV = 42%) was observed. The correlation coefficient also revealed a low and non-significant association between the location of two pathologies when they exist together (r = +0.06; p = 0.88). Clinical evaluation of Achilles tendon pain needs careful consideration into the possible co-existence of Plantaris pathology. The considerable difference observed in the location of PT and Mid-AT suggest possible isolated pathologies and differentials for Achilles tendon pain.

Quadriceps tendinopathy: a review-part 1: epidemiology and diagnosis

Overuse injuries of the extensor mechanism of the knee are common in both athletes and non-athletes and usually occur during activities associated with repetitive loading, stress, and knee extension. Historically, they have been labeled as Jumper's knee due to the high prevalence seen in the athletic community. In many published reports, the name "patellar tendinopathy" is used to describe this disorder of the quadriceps tendon at the patellar insertion, and the names are often used interchangeably. Numerous reports have been published describing extensor mechanism injuries in athletes, but there is a paucity of studies that focus on quadriceps tendinopathy. In addition, there is no universally accepted classification system for tendon pathology. Therefore, we performed a comprehensive literature review of these studies. This review consists of 2 parts. In the first part we review: (I) epidemiology and (II) diagnosis of quadriceps tendinopathy in the athlete as well as the general population. In the second part we discuss: (I) classification; (II) prognosis; and (III) treatment results.

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.

Sonographically Guided Plantaris Tendon Release: A Cadaveric Validation Study

BACKGROUND

The plantaris tendon (PT) has been implicated in the pathogenesis of symptoms in a subset of patients with Achilles region pain syndromes and traditionally has been managed via open surgical resection. Although the PT can be visualized on ultrasound, a minimally invasive technique for sonographically guided PT release has not been formally described.

OBJECTIVE

To validate a technique to perform sonographically guided PT release in an unembalmed cadaveric model.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Procedural skills laboratory in a tertiary medical center.

SUBJECTS

Twenty unembalmed cadaveric knee-ankle-foot specimens (10 right, 10 left) obtained from 16 donors (6 male, 10 female) ages 55-96 years (mean 82.6 years) with body mass indexes of 14.1-33.2 kg/m² (mean 23.3 kg/m² ).

METHODS

After simulated local anesthesia and sonographically guided hydrodissection of the plantaris tendon-Achilles tendon interval, a single experienced operator performed sonographically guided PT release on each specimen using an in-plane, lateral-to-medial approach, a commercially available, disposable 3.0-mm hook knife, and either a 17-5 MHz or 15-7 MHz linear array transducer. Each specimen was subsequently dissected to assess for PT release and iatrogenic injury.

MAIN OUTCOME

Status of the PT, Achilles tendon, and regional neurovascular structures as determined by dissection.

RESULTS

All 20 PT releases were completed in a single attempt through a 3- to 5-mm incision. Dissection confirmed complete PT release in all specimens without damage to the adjacent Achilles tendon or regional neurovascular structures.

CONCLUSION

Sonographically guided PT release is technically feasible and can be performed while avoiding injury to the Achilles tendon and regional neurovascular structures. Additional research is warranted to further define the role of sonographically guided PT release in patients with suspected PT-mediated Achilles region pain syndromes.

LEVEL OF EVIDENCE

IV.

Surgical plantaris tendon removal for patients with plantaris tendon-related pain only and a normal Achilles tendon: a case series

Objectives

Surgical removal of the plantaris tendon can cure plantaris-associated Achilles tendinopathy, a condition in which Achilles and plantaris tendinopathy coexist. However, rare cases with plantaris tendinopathy alone are often misdiagnosed due to a normal Achilles tendon.

Design and setting

Prospective case series study at one centre.

Participants

Ten consecutive patients (9 men and one woman, mean age 35 years, range 19–67) with plantaris tendon-related pain alone in altogether 13 tendons were included. All had had a long duration (median 10 months, range 3 months to 10 years) of pain symptoms on the medial side of the Achilles tendon mid-portion. Preoperative ultrasound showed thickened plantaris tendon but a normal Achilles tendon.

Interventions

Operative treatment consisting of ultrasound-guided excision of the plantaris tendon.

Primary and secondary outcome measures

Scores from Victorian Institute of Sports Assessment-Achilles questionnaire (VISA-A)were taken preoperatively and postoperatively (median duration 10 months). Patient satisfaction and time until full return to sports activity level was asked by a questionnaire.

Results

The VISA-A scores increased from 61 (range 45–81) preoperatively to 97 (range 94–100) postoperatively (p<0.01). Follow-up results at 10 months (range 7–72 months) on 9/10 patients showed full satisfaction and return to their preinjury sports or recreational activity

Conclusion

The plantaris tendon should be kept in mind when evaluating painful conditions in the Achilles tendon region, especially when no Achilles tendinopathy is present. Excision of the plantaris tendon via a minor surgical procedure in local anaesthesia results in a good outcome.

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.

Surgery in Tendinopathies

Tendinopathies are challenging. The term "tendinopathy" refers to clinical condition characterized by pain, swelling, and functional limitations of tendons and nearby structures. Tendinopathies give rise to significant morbidity, and, at present, only limited scientifically proven management modalities exist. Achilles and patellar tendons are among the most vulnerable tendons, and among the most frequent lower extremity overuse injuries. Achilles and patellar tendinopathies can be managed conservatively and surgically. Several surgical procedures have been described for both conditions, and, if performed well, they lead to a relatively higher rate of success with low complication.

Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part II: treatment options

The treatment of painful chronic tendinopathy is challenging. Multiple non-invasive and tendon-invasive methods are used. When traditional non-invasive treatments fail, the injections of platelet-rich plasma autologous blood or cortisone have become increasingly favored. However, there is little scientific evidence from human studies supporting injection treatment. As the last resort, intra- or peritendinous open or endoscopic surgery are employed even though these also show varying results. This ESSKA basic science committee current concepts review follows the first part on the biology, biomechanics and anatomy of tendinopathies, to provide a comprehensive overview of the latest treatment options for tendinopathy as reported in the literature.

Marked expression of TNF receptors in human peritendinous tissues including in nerve fascicles with axonal damage - Studies on tendinopathy and tennis elbow

BACKGROUND

The peritendinous connective tissues can have importance in chronic tendon pain. Recently cytokine TNF-α has been suggested to be involved in tendinopathic processes. It is not known how TNF-α and its receptors TNFR1 and TNFR2 are expressed in peritendinous tissues.

METHODS

The objective for this study was to immunohistochemically evaluate the expression patterns of these in the peritendinous tissue located between the plantaris and Achilles tendons and the one located superficially to the extensor origin at the elbow region for patients with tendinopathy/tennis elbow.

RESULTS

The nerve fascicles were of two types, one type being homogenously stained for the nerve markers βIII-tubulin and neurofilament and the other showing deficits for these suggesting features of axonal damage. Much more distinct TNFR1/TNFR2 immunoreactions were seen for the latter nerve fascicles. TNFR1 was seen in axons, TNFR2 mainly in Schwann cells. TNFR1 and particularly TNFR2 were seen in walls of parts of blood vessels. The dispersed cells showed frequently TNFR1 and TNFR2 immunoreactivity.

DISCUSSION

These findings suggest that TNF-α can be related to degenerative events but also attempts for healing concerning the nerve structures. The marked expression of the TNF-α system in the peritendinous tissue suggests an impact of TNF-α in tendinopathy/tennis elbow.

Glutamate signaling through the NMDA receptor reduces the expression of scleraxis in plantaris tendon derived cells

Background

A body of evidence demonstrating changes to the glutaminergic system in tendinopathy has recently emerged. This hypothesis was further tested by studying the effects of glutamate on the tenocyte phenotype, and the impact of loading and exposure to glucocorticoids on the glutamate signaling machinery.

Methods

Plantaris tendon tissue and cultured plantaris tendon derived cells were immunohisto-/cytochemically stained for glutamate, N-Methyl-D-Aspartate receptor 1 (NMDAR1) and vesicular glutamate transporter 2 (VGluT2). Primary cells were exposed to glutamate or receptor agonist NMDA. Cell death/viability was measured via LDH/MTS assays, and Western blot for cleaved caspase 3 (c-caspase 3) and cleaved poly (ADP-ribose) polymerase (c-PARP). Scleraxis mRNA (Scx)/protein(SCX) were analyzed by qPCR and Western blot, respectively. A FlexCell system was used to apply cyclic strain. The effect of glucocorticoids was studies by adding dexamethasone (Dex). The mRNA of the glutamate synthesizing enzymes Got1 and Gls, and NMDAR1 protein were measured. Levels of free glutamate were determined by a colorimetric assay.

Results

Immunoreactions for glutamate, VGluT2, and NMDAR1 were found in tenocytes and peritendinous cells in tissue sections and in cultured cells. Cell death was induced by high concentrations of glutamate but not by NMDA. Scleraxis mRNA/protein was down-regulated in response to NMDA/glutamate stimulation. Cyclic strain increased, and Dex decreased, Gls and Got1 mRNA expression. Free glutamate levels were lower after Dex exposure.

Conclusions

In conclusion, NMDA receptor stimulation leads to a reduction of scleraxis expression that may be involved in a change of phenotype in tendon cells. Glutamate synthesis is increased in tendon cells in response to strain and decreased by glucocorticoid stimulation. This implies that locally produced glutamate could be involved in the tissue changes observed in tendinopathy.

Non-insertional Achilles tendinopathy

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

The plantaris tendon: a narrative review focusing on anatomical features and clinical importance

In recent years, the plantaris tendon has been implicated in the development of chronic painful mid-portion Achilles tendinopathy. In some cases, a thickened plantaris tendon is closely associated with the Achilles tendon, and surgical excision of the plantaris tendon has been reported to be curative in patients who have not derived benefit following conservative treatment and surgical interventions. The aim of this review is to outline the basic aspects of, and the recent research findings, related to the plantaris tendon, covering anatomical and clinical studies including those dealing with histology, imaging and treatment. Cite this article: Bone Joint J 2016;98-B:1312-19.

The tenocyte phenotype of human primary tendon cells in vitro is reduced by glucocorticoids

Background

The use of corticosteroids (e.g., dexamethasone) as treatment for tendinopathy has recently been questioned as higher risks for ruptures have been observed clinically. In vitro studies have reported that dexamethasone exposed tendon cells, tenocytes, show reduced cell viability and collagen production. Little is known about the effect of dexamethasone on the characteristics of tenocytes. Furthermore, there are uncertainties about the existence of apoptosis and if the reduction of collagen affects all collagen subtypes.

Methods

We evaluated these aspects by exposing primary tendon cells to dexamethasone (Dex) in concentrations ranging from 1 to 1000 nM. Gene expression of the specific tenocyte markers scleraxis (Scx) and tenomodulin (Tnmd) and markers for other mesenchymal lineages, such as bone (Alpl, Ocn), cartilage (Acan, Sox9) and fat (Cebpα, Pparg) was measured via qPCR. Cell viability and proliferation was calculated using a MTS Assay. Cell death was measured by LDH assay and cleaved caspase-3 using Western Blot. Gene expression of collagen subtypes Col1, Col3 and Col14 was analyzed using qPCR.

Results

Stimulation with Dex decreased cell viability and LDH levels. Dex also induced a significant reduction of Scx gene expression and a marked loss of fibroblast like cell shape. The mRNA for all examined collagen subtypes was found to be down-regulated. Among non-tendinous genes only Pparg was significantly increased, whereas Acan, Alpl and Sox9 were reduced.

Conclusions

These results indicate a Dex induced phenotype drift of the tenocytes by reducing scleraxis expression. Reduction of several collagen subtypes, but not cell death, seems to be a feature of Dex induced tissue degeneration.

Differential Plantaris-Achilles Tendon Motion: A Sonographic and Cadaveric Investigation

BACKGROUND

Differential motion between the plantaris and Achilles tendons has been hypothesized to contribute to pain in some patients presenting with Achilles tendinopathy. However, objective evidence of differential Achilles-plantaris motion is currently lacking from the literature.

OBJECTIVE

To determine whether differential, multidirectional motion exists between the plantaris tendon (PT) and Achilles tendon (AT) as documented by dynamic ultrasound (US) and postdissection examination in an unembalmed cadaveric model.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Procedural skills laboratory in a tertiary medical center.

SUBJECTS

Twenty unembalmed knee-ankle-foot specimens (9 right, 11 left) obtained from 6 male and 10 female donors ages 55-96 years (mean 80 years) with body mass indices of 14.1-33.2 kg/m² (mean 22.5 kg/m²).

METHODS

A single, experienced operator used high-resolution dynamic US to qualitatively document differential PT-AT motion during passive ankle dorsiflexion-plantarflexion. Specimens were then dissected and passive dorsiflexion-plantarflexion was repeated while differential PT-AT motion was visualized directly.

MAIN OUTCOME MEASUREMENTS

Presence or absence of multidirectional differential PT-AT motion.

RESULTS

All 20 specimens exhibited smooth but variable amplitude multidirectional differential PT-AT motion. Whereas US readily demonstrated medial-lateral and anterior-posterior PT motion relative to the AT, differential longitudinal motion was only appreciated on dissection and direct inspection. Many specimens exhibited partial or complete encasement of the PT between the gastrocnemius portion of the AT and the soleus aponeurosis.

CONCLUSION

Some degree of multidirectional differential PT-AT motion appears to be a normal phenomenon, and PT motion can be evaluated sonographically in both the medial-lateral and anterior-posterior directions. The existence of normal differential PT-AT motion suggests that alterations in PT motion or repetitive stress within the PT-AT interval may produce symptoms in some patients presenting with Achilles region pain syndromes. The PT should be evaluated in all patients presenting with Achilles, plantaris, or calf pain syndromes. Future research would benefit from the development of a sonographic classification system for PT anatomy and motion with the goal of differentiating normal versus pathologic states and identifying risk factors for symptom development.

LEVEL OF EVIDENCE

IV.

How to diagnose plantaris tendon involvement in midportion Achilles tendinopathy - clinical and imaging findings

Background

The purpose of this investigation was to evaluate if clinical assessment, Ultrasound + Colour Doppler (US + CD) and Ultrasound Tissue Characterisation (UTC) can be useful in detecting plantaris tendon involvement in patients with midportion Achilles tendinopathy.

Methods

Twenty-three tendons in 18 patients (14 men, mean age: 37 years and 4 women: 44 years) (5 patients with bilateral tendons) with midportion Achilles tendinopathy were surgically treated with a scraping procedure and plantaris tendon removal. For all tendons, clinical assessment, Ultrasound + Colour Doppler (US + CD) examination and Ultrasound Tissue Characterisation (UTC) were performed.

Results

At surgery, all 23 cases had a plantaris tendon located close to the medial side of the Achilles tendon. There was vascularised fat tissue in the interface between the Achilles and plantaris tendons. Clinical assessment revealed localised medial activity-related pain in 20/23 tendons and focal medial tendon tenderness in 20/23 tendons. For US + CD, 20/23 tendons had a tendon-like structure interpreted to be the plantaris tendon and localised high blood flow in close relation to the medial side of the Achilles. For UTC, 19/23 tendons had disorganised (type 3 and 4) echopixels located only in the medial part of the Achilles tendon indicating possible plantaris tendon involvement.

Conclusions

US + CD directly, and clinical assessment indirectly, can detect a close by located plantaris tendon in a high proportion of patients with midportion Achilles tendinopathy. UTC could complement US + CD and clinical assessment by demonstrating disorganised focal medial Achilles tendon structure indicative of possible plantaris involvement.

Marked innervation but also signs of nerve degeneration in between the Achilles and plantaris tendons and presence of innervation within the plantaris tendon in midportion Achilles tendinopathy

OBJECTIVES

The plantaris tendon is increasingly recognised as an important factor in midportion Achilles tendinopathy. Its innervation pattern is completely unknown.

METHODS

Plantaris tendons (n=56) and associated peritendinous tissue from 46 patients with midportion Achilles tendinopathy and where the plantaris tendon was closely related to the Achilles tendon were evaluated. Morphological evaluations and stainings for nerve markers [general (PGP9.5), sensory (CGRP), sympathetic (TH)], glutamate NMDA receptor and Schwann cells (S-100β) were made.

RESULTS

A marked innervation, as evidenced by evaluation for PGP9.5 reactions, occurred in the peritendinous tissue located between the plantaris and Achilles tendons. It contained sensory and to some extent sympathetic and NMDAR1-positive axons. There was also an innervation in the zones of connective tissue within the plantaris tendons. Interestingly, some of the nerve fascicles showed a partial lack of axonal reactions.

CONCLUSION

New information on the innervation patterns for the plantaris tendon in situations with midportion Achilles tendinopathy has here been obtained. The peritendinous tissue was found to be markedly innervated and there was also innervation within the plantaris tendon. Furthermore, axonal degeneration is likely to occur. Both features should be further taken into account when considering the relationship between the nervous system and tendinopathy.