Ultrasound elastography and ultrasound tissue characterisation for tendon evaluation

Acute Effects of Running on Shear Wave Elastography Measures of the Achilles Tendon and Calf Muscles in Professional Female Handball and Volleyball Players

Shear Wave Elastography (SWE) is currently used to detect tissue pathologies, i.e., tendinopathy. For preventive medicine, it is important to examine the sensitivity of SWE and to investigate how stiffness measures are affected by methodological variables. The aim of this study is to examine shear wave elastography (SWE) measures in order to compare the pre- and post-running values and to determine the correlation between the shear wave speed values (m/s). SWE examinations of the Achilles tendon (AT), soleus muscle (MS) and gastrocnemius muscle (MG)) were performed in 24 healthy professional female athletes. Measurements of the shear wave speed (m/s) were taken before and after incremental treadmill running until exhaustion. Correlations were investigated using the Pearson correlation coefficient and were examined for significance using the Student's t-test. The pre- and post-exercise shear wave speed did not differ. The pre-exercise and post-exercise stiffness for MS (r = 0.613), MG (r = 0.609) and AT (r = 0.583) correlated strongly. The pre-exercise values and changes in stiffness showed a significant correlation (p < 0.001). In professional athletes, acute exercise induces different tissue stiffness changes in AT, MS and MG for each individual. Thus, exercise activity immediately prior to the SWE measurement needs to be factored in when evaluating tissue stiffness.

Low-volume Hydrodissection for the Treatment of Chronic Achilles Tendinopathy

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

Stiffness of Muscles and Tendons of the Lower Limb of Professional and Semiprofessional Athletes Using Shear Wave Elastography

OBJECTIVE

Shear wave elastography (SWE) allows assessment of muscle and tendon stiffness and can be used to diagnose soft tissue pathologies such as tendinopathies. In sports medicine, SWE may have the potential to uncover structural changes early on before they lead to functional impairment. To systematically analyze possible differences in tendon and muscle stiffness of the lower limb between professional (PG) and semiprofessional female athletes (SG) using SWE and to compile reference values for developing preventive medicine approaches for professional athletes.

METHODS

Standardized SWE of both lower limb tendons and muscles (Achilles tendon [AT], soleus muscle insertion [SM], patellar tendon [PT], quadriceps tendon [QT], vastus medialis muscle [VM]) in the longitudinal plane was performed with the tendons in relaxed position in 24 healthy professional female athletes (PG) in comparison with 24 healthy semiprofessional female athletes (SG).

RESULTS

Median tendon and muscle stiffness was significantly higher in professional athletes (AT:PG, 11.12 m/s vs SG, 7.33 m/s, P < .001; SM: 1.77 m/s vs 1.14 m/s, P < .001; VM: 1.63 m/s vs 0.87 m/s, P < .001; QT: 3.31 m/s vs 2.61 m/s, P < .05). There was no significant difference in patellar tendon stiffness between PG and SG (PT: 2.57 m/s vs 3.21, P = .25).

CONCLUSION

Professional female athletes have higher stiffness values than semiprofessional female athletes in lower limb muscles and tendons, except for the patellar tendon. Knowledge of such differences is necessary for diagnosing tendinopathy and injuries. Musculoskeletal SWE could offer great benefits in sports medicine as well as in rehabilitation and preventive medicine.

Review of human supraspinatus tendon mechanics. Part II: tendon healing response and characterization of tendon health

Overuse injuries of the rotator cuff, particularly of the supraspinatus tendon (SST), are highly prevalent and debilitating in work, sport, and daily activities. Despite the clinical significance of these injuries, there remains a large degree of uncertainty regarding the pathophysiology of injury, optimal methods of nonoperative and operative repair, and how to adequately assess tendon injury and healing. The tendon response to fatigue damage resulting from overuse is different from that of acute rupture and results in either an adaptive (healing) or a maladaptive (degenerative) response. Factors associated with the degenerative response include increasing age, smoking, hypercholesterolemia, biological sex (variable by tendon), diabetes mellitus, and excessive load post fatigue damage. After injury, the average healing rate of tendon is approximately 1% per day and may be significantly influenced by biologic sex (females have lower collagen synthesis rates) and excessive load after damage. Although magnetic resonance imaging (MRI) is considered the gold standard in assessing acute tears as well as tendinopathic change in the SST, ultrasonography has proven to be a valuable tool to measure tendinopathic change in real time. Ultrasonography can determine multiple mechanical and structural parameters of the SST that are altered in fatigue loading. Thus, ultrasonography may be utilized to understand how these parameters change in response to SST overuse, and may aid in determining the activity level that places the SST at greater risk of rupture.

2D-SWE of the Metacarpophalangeal Joint Capsule in Horses

(1) Two-dimensional shear wave elastography (2D-SWE) employs an ultrasound impulse to produce transversely oriented shear waves, which travel through the surrounding tissue according to the stiffness of the tissue itself. The study aimed to assess the reliability of 2D-SWE for evaluating the elastosonographic appearance of the distal attachment of the fetlock joint capsule (DJC) in sound horses and in horses with osteoarthritis (OA) (2). According to a thorough evaluation of metacarpophalangeal joint (MCPJ), adult horses were divided in a sound Group (H) and in OA Group (P). Thereafter, a 2D-SWE of MCPJs was performed. Shear wave velocity (m/sec) and Young’s modulus (kPa) were calculated independently by two operators at each selected ROI. Statistical analysis was performed with R software. (3) Results: 2D-SWE had good–excellent inter-CC and intra-CC in both groups. Differences in m/s and kPa between Groups H and P were found in transverse scans with lower values in Group P. No correlation with age or DJC thickness was found. (4) Conclusions: 2D-SWE was repeatable and reproducible. In Group H, DJC was statistically stiffer than in Group P only in transverse scan. The technique showed poor sensitivity and specificity in differentiating fetlocks affected by OA.

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

INTRODUCTION

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

OBJECTIVE

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

ISRCTN46462385.

Feasibility Trial to Evaluate Tendon Stiffness Obtained from Shear Wave Elastography Imaging as a Biomarker of Aromatase Inhibitor-Induced Arthralgias

Aromatase inhibitor-induced arthralgia (AIA) comprises significant, activity-limiting musculoskeletal symptoms, including joint pain, myalgia, and joint stiffness. We conducted a prospective feasibility study in postmenopausal women diagnosed with early-stage (0–3) hormone receptor positive (HR+) breast cancer who were candidates for treatment with adjuvant AI therapy (n = 16). Tendons of the hands and wrists and the median nerve were imaged using gray-scale and power Doppler ultrasound (US) and US SWE. Arthralgia symptoms were evaluated using the Breast Cancer Prevention Trial (BCPT) Symptom Checklist musculoskeletal subscale (MS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and stiffness subscales. At baseline, there were significant differences in the SW velocities of tendons between dominant and nondominant hands. Increased velocity in 2 of 6 tendons and the median nerve was associated with greater pain at baseline, whereas slower velocity of the extensor digitorum tendon (suggesting decreased stiffness) was associated with a higher WOMAC stiffness score. Increased SW velocity (suggestive of increased stiffness) at baseline in the abductor pollicis longus tendon was associated with a worsening of all three pain and stiffness measures by 6 months. Future studies should evaluate SWE scores related to AIA outcomes in a larger sample size.

Equine flexor tendon imaging part 1: Recent developments in ultrasonography, with focus on the superficial digital flexor tendon

Flexor tendon injuries are a major cause of lameness in performance horses and have considerable impact on equine welfare and the wider horse industry. Ageing and repetitive strain frequently cause varying degrees of tendon micro-damage prior to the recognition of clinical tendinopathy. Whilst B-mode ultrasonography is most commonly utilised for detection and monitoring of tendon lesions at the metacarpal/metatarsal level, the emphasis of recent research has focused on the identification of subclinical tendon damage in order to prevent further tendon injury and improve outcomes. The introduction of elastography, acoustoelastography and ultrasound tissue characterisation in the field of equine orthopaedics shows promising results and might find wider use in equine practice as clinical development continues. Based on the substantial number of research studies on tendon imaging published over the past decade this literature review aims to examine the currently used ultrasonographic imaging techniques and their limitations, and to introduce and critically appraise new modalities that could potentially change the clinical approach to equine flexor tendon imaging.

Line- and Point-Focused Extracorporeal Shock Wave Therapy for Achilles Tendinopathy: A Placebo-Controlled RCT Study

BACKGROUND

Extracorporeal shock wave therapy (ESWT) is a widely considered treatment option for Achilles tendinopathy. Line-focused ESWT is a novel technique treating a larger tendon area than point-focused ESWT. Monitoring capacities of clinical symptoms with ultrasound under ESWT treatment are unknown.

HYPOTHESIS

Point- and line-focused ESWT have a superior outcome than placebo ESWT. ESWT leads to morphological tendon changes detectable with ultrasound.

STUDY DESIGN

Single-blinded placebo-controlled randomized contolled trial.

LEVEL OF EVIDENCE

Level 1.

METHODS

The study was conducted in 3 cohorts, namely ESWT point (n = 21), ESWT line (n = 24), and ESWT placebo (n = 21). Victorian Institute of Sports Assessment-Achilles (VISA-A) score was measured before the intervention (T0), after 6 weeks (T1), and after 24 weeks (T2). All cohorts performed daily physiotherapy for 24 weeks and received 4 sessions of point-focused, line-focused, or placebo ESWT in the first 6 weeks. Ultrasound was performed with B-mode, power Doppler, shear wave elastography (SWE) at T0 and T2 and with ultrasound tissue characterization (UTC) at T0, T1, and T2. Data were analyzed with a mixed analysis of variance and t test.

RESULTS

There was a significant VISA-A improvement over time for all groups (P < 0.001). ESWT point had the strongest VISA-A score improvement +23 (ESWT line: +18; ESWT placebo: +15), but there was no significant interaction between time and any of the groups: F(4, 116) = 1.393; P = 0.24. UTC, power Doppler, and B-mode could not show significant alterations over time. SWE revealed a significant increase of elastic properties for ESWT point in the insertion (t = -3.113, P = 0.03) and midportion (t = -2.627, P = 0.02) over time.

CONCLUSION

There is a significant VISA-A score improvement for all study groups without a statistically significant benefit for ESWT point or ESWT line compared with ESWT placebo. Tendon adaptation could only be detected with SWE for ESWT point.

CLINICAL RELEVANCE

The present study could not detect any statistically relevant effect of ESWT compared to placebo. SWE is able to demonstrate tendon adaptation.

Achilles Tendinopathy: Evaluation, Rehabilitation, and Prevention

ABSTRACT

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

Mapping theme trends and recognizing research hot spots in the use of ultrasound in orthopaedics: a bibliometric analysis of global research

BACKGROUND

In the past decade, ultrasound has been increasingly used in the field of orthopaedics. The purpose of this study is to inspire future research in this field by analyzing the publications relating to ultrasound research in orthopaedics.

METHODS

All relevant articles published between 2009 and 2020 were retrieved from Web of Science. Statistical Package for Social Science and GraphPad Prism 8 software were used to generate and analyse diagrams. VOSviewer software and CiteSpace were employed to visualize the research trends based on co-occurring keywords. Finally, we obtained information about relevant clinical randomized controlled trials (http://clinicaltrials.gov.com/).

RESULTS

The United States had the most publications in this field and the most citations and the highest H-index. Furthermore, Skeletal Radiology published the most papers related to the use of ultrasound in orthopaedics, Ozcakar L published the most papers, and a study by Kwon, YM had the highest citation frequency. The keywords "MRI", "complication", "female" and "male" were identified as being indicative of emerging topics.

CONCLUSIONS

While the contribution of United States to publications in this field has been substantial, the future contributions of China cannot be ignored. Moreover, it is hypothesized that diagnostic and epidemiological aspects may become hotspots.

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.

Serial Ultrasonographic and Real-Time Elastosonographic Assessment of the Ovine Common Calcaneal Tendon, after an Experimentally Induced Tendinopathy

Real-time elastosonography (RTE) is a recently described, non-invasive, ultrasonographic technique developed to assess tissue elasticity. The main aim of this study was to investigate the ultrasonographic and elastosonographic appearance of the common calcaneal tendon (CCT) in an ovine model, and to monitor the progression of tendon healing after an experimentally-induced tendinopathy. Sound tendons were initially evaluated (T₀) with a caliper and by a single operator with ultrasound. Ultrasonographic and elastosonographic images were then acquired. Subsequently, ultrasound-guided tendon lesions were induced by injecting 500 IU of Type IA collagenases proximally to the calcaneal tuberosity. Caliper measurement, ultrasonography and elastosonography were then repeated at 15 (T₁), 30 (T₂) and 60 (T₃) days. Clinically measured width of the tendon, ultrasonographic thickness and width and percentage of hard (Elx-t%hrd) and soft (Elx-t%sft) tissue were recorded. Statistical analysis was performed on the data collected; statistical significance was set at p < 0.05. Intra-class correlation coefficient (ICC) revealed good (0.68) repeatability of elastosonographic evaluation of the CCT. The tendon width was significantly increased when comparing T₀ with T_1–2 and decreased when comparing T_1–2 with T₃. Ultrasound-assessed thickness was significantly increased between T₀–T₁ and decreased between T₁-T_2–3. Elx-t%hrd was significantly decreased at T_1–2–3 and Elx-t%sft was significantly increased at T_1–2–3. In conclusion, the ovine CCT is a highly stiff structure that undergoes a severe loss of stiffness during the healing process. Thickness and width of the tendon increased during the first 30 days and then reduced progressively along the subsequent 30 days. Ultrasonographic appearance of the tendon remained severely abnormal and the tendon showed severely reduced elastic proprieties 60 days after lesion induction.

Evaluation of Current Symptoms in Postoperative Achilles Tendons: A Multimodal Ultrasound Study

(1) Background: It is unknown which imaging parameters are associated with clinical persistent symptoms in postoperative Achilles tendons. This study used B-Mode, Power Doppler (PD-US), Ultrasound Tissue Characterization (UTC) and Shear Wave Elastography (SWE) to investigate which imaging parameters are associated with persistent symptoms in postoperative Achilles tendon tissue. (2) Methods: Retrospective, cross-sectional, multimodal imaging study. Based on the VISA-A score, postoperative tendons were assigned to two groups: 1. asymptomatic (VISA-A ≥ 90, n = 18); 2. symptomatic (VISA-A < 90, n = 10). The following imaging parameters were analyzed: UTC (echo type I, II, III, IV), B-Mode (diameter, cross sectional area, calcification, fiber irregularity), PD-US (Öhberg score) and SWE (SWE 3 mm, SWE area) using a t-test and a Mann–Whitney U test. (3) Results: SWE and PD-US showed significantly reduced elasticity and increased neovascularization in symptomatic tendons (SWE 3 mm p = 0.031, SWE area p = 0.046, Öhberg score p < 0.001). The only significant correlation between imaging parameters and the VISA-A score was assessed for SWE 3 mm (r = 0.378; p = 0.047) and the Öhberg score (r = −0.737; p < 0.001). Conclusions: Symptomatic postoperative Achilles tendons showed increased neovascularization and lower SWE values than asymptomatic ones. Future studies should examine the diagnostic accuracy of PD-US and SWE in detecting current symptoms in postoperative Achilles tendons.

Sonoelastography of Normal Canine Common Calcaneal Tendon: Preliminary Results

Shear wave elastography (SWE) is a feasible and newly developed ultrasonographic technique which is able to assess elasticity of tissues. The aim of this work was to assess the feasibility of SWE on the normal canine common calcaneal tendon (CCT) evaluating the intra-operator repeatability and reproducibility of single measurements and stiffness of different anatomic CCT portions was examined. Tendons were first evaluated with B-mode ultrasound with a linear probe 8.5 to 10 MHz in longitudinal section with slight flexed tarsocrural joint and a gel-pad. Common calcaneal tendon was divided into three different anatomical regions. Shear wave elastography was performed in each region by two operators and quantitative evaluation (m/s and kPa) was performed on the most representative images. Region of interest (0.15 cm) was settled. Intraclass correlation coefficient (ICC) results were classified using the following scale: 0.00 to 0.20 = poor; 0.20 to 0.40 = fair; 0.40 to 075 = good; >0.75 = excellent. Ten adult dogs were enrolled. Intra-operator ICC values were >0.75 for both operators in every tendon portion. Inter-operator SWE ICC values for m/s measurements were 0.3, 0.61 and 0.61 for the enthesis, intermediate portion and the myotendinous junction respectively; for kPa measurements, values were respectively 0.3, 0.7 and 0.81. The three CCT portions were significantly different in stiffness (p-value < 0.001 for both m/s and kPa measurements). These preliminary results provide evidence that SWE is potentially appliable to assess mechanical properties of canine CCT affected by tendinopathies.

Effects of Hyperosmolar Dextrose Injection in Patients With Rotator Cuff Disease and Bursitis: A Randomized Controlled Trial

OBJECTIVE

To determine whether dextrose prolotherapy offers clinical benefits in patients with shoulder pain and bursitis.

DESIGN

Double-blinded, randomized controlled trial.

SETTING

Outpatient rehabilitation department of a single medical center.

PARTICIPANTS

Patients (N=50) who had received a diagnosis of shoulder pain and bursitis through clinical tests and ultrasound examination.

INTERVENTIONS

Participants were randomly assigned to the 15% dextrose injection (D15W) group or the placebo group to receive either D15W or normal saline injection, respectively. All participants received ultrasound-guidance bursal injection every 2 weeks for a total of 3 injections.

MAIN OUTCOME MEASURES

The primary outcome was maximal pain level while performing activities. The secondary outcomes included resting pain level, function and disability assessment results, and ultrasonographic parameters. Participants were followed up for 3 months after completion of the injection course.

RESULTS

No significant differences in baseline characteristics were observed between the D15W and placebo groups. Significant time effects were observed for all outcome parameters (all P<.05); however, time × group effects were nonsignificant for all outcomes, except for tissue elasticity (P=.026).

CONCLUSIONS

Supporting evidence is insufficient regarding the clinical benefits of 15% dextrose bursal injection administered through 3 sessions in patients with chronic shoulder pain and bursitis. The findings indicate that these injections may increase the tissue stiffness of the supraspinatus tendon, as indicated by elastography assessment results, but further research is required to determine the nature of such changes in elastography findings.

Evaluation of a Torn Achilles Tendon After Surgical Repair: An Ultrasound and Elastographic Study With 1-Year Follow-up

OBJECTIVES

The aim of this study was to evaluate the healing process of a torn Achilles tendon after surgical repair using ultrasound elastography.

METHODS

This study was set in a prospective case-control analytic design. Patients who underwent surgical repair of complete rupture of the Achilles tendon were enrolled, together with a control group. The data for the patient group were assessed at 12, 24, and 48 weeks postoperatively. All patients were evaluated by the American Orthopedic Foot and Ankle Scale. Values for the thickness, the cross-sectional area, strain elastography, and shear wave elastography (SWE) were compared on a high-resolution Doppler ultrasound system.

RESULTS

The percentage of the red-to-yellow code was the highest (57.7%) at the 12th-week evaluation, and the percentage of the green code was the highest at the 24th-week (53.8%) and 48th-week (69.2%) evaluations. With respect to color codes on the nonruptured side, the percentage of green increased and the percentage of blue decreased over time (P = .002). The SWE values increased over time on the ruptured side and decreased on the nonruptured side. There was a positive correlation (moderate) between the American Orthopedic Foot and Ankle Scale and SWE values at the 24th- and 48th-week evaluations.

CONCLUSIONS

The results of this study demonstrated that the Achilles tendon seems to become stiffer with the healing process. Ultrasound elastography can provide structural information about the healing process of the Achilles tendon after surgical repair and can quantify findings for follow-up.

ELASTOGRAPHIC ANALYSIS OF THE SUPRASPINATUS TENDON IN DIFFERENT AGE GROUPS

OBJECTIVE

To compare the mechanical properties of the supraspinatus tendon in different age groups using Supersonic Shearwave Imaging (SSI) elastography.

METHODS

We evaluated 38 healthy individuals of both genders, 20 being in the range of 20 to 35 years and 18 being over 60 years. The shear modulus of the supraspinatus tendon was measured by SSI elastography, always on the right side. Means between age groups were compared and statistically analyzed using the Shapiro-Wilk normality test followed by the student's t-test and were established as a statistically significant value of p ≤ 0.05.

RESULTS

A statistically significant difference was observed when the mean values of the shear modulus of the supraspinatus tendon of young adults (23.98 ± 9.94 KpA) were compared with those of older adults (17.92 ± 6.17 KpA).

CONCLUSION

We found a difference between the means of the shear modulus measured by the SSI elastography, showing a significant decrease of the shear modulus with the chronological age progression. Level of Evidence III, Diagnostic Studies - Investigating a Diagnostic Test.

Intra individual comparison of unilateral Achilles tendinopathy using B-mode, power Doppler, ultrasound tissue characterization and shear wave elastography

BACKGROUND

The asymptomatic side of unilateral Achilles tendinopathy (AT) is used as a reference in ultrasound. However, this procedure has not been evaluated in a comparative analysis using B-mode (B-US), power Doppler (PD-US), ultrasound tissue characterization (UTC) and shear wave elastography (SWE).

METHODS

Retrospective cross-sectional study. Tendons were assigned to 3 groups: 1) asymptomatic side of unilateral AT N.=55; 2) symptomatic side of unilateral AT N.=55; and 3) young reference group N.=29. The following parameters were analyzed separately for the insertion and midportion: UTC (echo type I, II, III, IV), B-US (diameter, cross sectional area), PD-US (Öhberg Score) and SWE (SWE 3 mm, SWE area) using a Wilcoxon Test (group 1 vs. 2) and a Kruskal-Wallis Test (group 1 vs. 2 vs. 3).

RESULTS

The Wilcoxon Test making an isolated comparison between group 1 vs. 2 revealed a significant difference for all parameters of B-US, PD-US, UTC and SWE (P<0.001, P=0.042), except for the insertion in UTC. However, in the overall analysis including the reference group, the Kruskal-Wallis Test could only detect a significant difference between group 1 vs. 2 for PD-US (P<0.001). Thus, group 1 and 2 had significantly more pathological parameters in B-US (P<0.001, P=0.027), SWE (P<0.001, P=0.008) and UTC (type I, III, IV P<0.001) in both, insertion and midportion, compared to the reference group.

CONCLUSIONS

The asymptomatic side of unilateral AT seems to show subclinical tendons alterations in B-US, SWE and UTC in comparison to a young and healthy control group. The asymptomatic side of unilateral AT especially with detectable neovascularization might be at risk for future symptoms. Further studies must examine whether the asymptomatic side can still serve as a reference for intra individual comparison in clinical evaluation.

Eccentric and Isometric Exercises in Achilles Tendinopathy Evaluated by the VISA-A Score and Shear Wave Elastography

BACKGROUND

Apart from eccentric exercises (EE), isometric exercises (ISO) might be a treatment option for Achilles tendinopathy. Shear wave elastography (SWE) provides information for diagnosis and for monitoring tissue elasticity, which is altered in symptomatic tendons.

HYPOTHESIS

Isometric exercises will have a beneficial effect on patients' outcome scores. Based on SWE, insertional and midportion tendon parts will differ in their elastic properties according to current symptoms.

STUDY DESIGN

Randomized clinical trial.

LEVEL OF EVIDENCE

Level 2.

METHODS

Group 1 (EE; n = 20; 12 males, 8 females; mean age, 52 ± 8.98 years) and group 2 (EE + ISO; n = 22; 15 males, 7 females; mean age, 47 ± 15.11 years) performed exercises for 3 months. Measurement points were before exercises were initiated as well as after 1 and 3 months using the Victorian Institute of Sports Assessment-Achilles (VISA-A) score, American Orthopaedic Foot & Ankle Society score, and SWE (insertion and midportion).

RESULTS

Both groups improved significantly, but there were no significant interindividual differences (VISA-A; P = 0.362) between group 1 (n = 15; +15 VISA-A) and group 2 (n = 15; +15 VISA-A). The symptomatic insertion (symptomatic, 136.89 kPa; asymptomatic, 174.68 kPa; P = 0.045) and the symptomatic midportion of the Achilles tendon (symptomatic, 184.40 kPa; asymptomatic, 215.41 kPa; P = 0.039) had significantly lower Young modulus compared with the asymptomatic tendons. The midportion location had significantly higher Young modulus than the insertional part of the tendon (P = 0.005).

CONCLUSION

Isometric exercises do not have additional benefit when combined with eccentric exercises, as assessed over a 3-month intervention period. SWE is able to distinguish between insertional and midportion tendon parts in a symptomatic and asymptomatic state.

CLINICAL RELEVANCE

The present study shows no additional effect of ISO when added to baseline EE in treating Achilles tendinopathy. Different elastic properties of the insertional and midportion tendon have to be taken into consideration when rating a tendon as pathologic.

Quantitative measures of tissue mechanics to detect hypermobile Ehlers-Danlos syndrome and hypermobility syndrome disorders: a systematic review

Hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD) are heritable connective tissue disorders associated with pain, activity limitations and participation restrictions. A key feature is reported to be reduced stiffness and increased extensibility and elasticity of connective tissues. Yet diagnosis relies on assessment of joint range of motion, which may be influenced by other factors, and semi-quantitative assessment of forearm skin extensibility. The objective of this systematic review was to determine if quantitative measures of tissue mechanics can discriminate between hEDS/HSD and healthy tissues. Literature was identified via online databases (AMED, CINAHL+, EMBASE, MEDLINE and SportDiscus) and snowballing. Studies were included if participants had a confirmed diagnosis of hEDS/HSD (or equivalent diagnosis) using internationally recognised criteria, a healthy control group was used as a comparator, and objective measures of tissue stiffness, extensibility or elasticity of muscle, tendon, connective tissue or skin were reported. Included studies were critically appraised, followed by group discussion, consensus and narrative synthesis. Two hundred three potentially relevant studies were identified. Application of the inclusion criteria resulted in four studies being included. A range of quantitative approaches to studying tissue mechanics were used, including diagnostic ultrasound. Overall, three of the four studies found that at least one measure of tissue mechanics distinguished between people with hEDS/HSD and healthy controls. The studies were generally conducted and reported to high standards. Quantitative measures of tissue mechanics have the potential to contribute towards more objective diagnosis of hEDS/HSD. Further validation, particularly within diagnostic scenarios, is required.

Utility of Ultrasound Elastography in Evaluation of Carpal Tunnel Syndrome: A Systematic Review and Meta-analysis

We systematically reviewed observational studies investigating ultrasound elastography for median nerves in the carpal tunnel syndrome (CTS) population. PubMed and Embase were studied from the earliest record to April 2019. The primary outcome was the comparison of elasticity of the median nerve between participants with and without CTS, quantified by the standardized mean difference (SMD) and its 95% confidence interval. The median nerve is considered to be stiffer in the CTS population when the SMD of tissue strain is negative, or that of strain ratio, shear modulus and shear wave velocity are positive. The present meta-analysis included 17 studies, evaluating 1401 wrists. Our result showed that regardless of the ultrasound elastography mode (tissue strain, strain ratio, shear modulus and shear wave velocity) used, median nerves at the wrist level in patients with CTS were consistently stiffer than those in healthy controls. Importantly, ultrasound elastography revealed its potential in differentiating CTS of different severity.