Sonoelastography of Plantar Fascia: Reproducibility and Pattern Description in Healthy Subjects and Symptomatic Subjects

Ultrasonographic Evaluation of Thickness and Stiffness of Achilles Tendon and Plantar Fascia in Type 2 Diabetics Patients: A Cross-sectional Observation Study

Background

Diabetes mellitus (DM) can contribute to the development of foot ulcers, a known complication of DM with a high financial and social burden. Achilles tendon (AT) and plantar fascia (PF) are well known to play an important role in foot biomechanics. The present study focuses on the alteration in thickness and stiffness of the AT and PF in Type 2 DM patients compared with the normal controls.

Methods

A cross-sectional observational study was conducted with 55 DM patients and 55 healthy volunteers as controls. The thickness of the AT and PF were measured using B-mode ultrasound and stiffness was measured using shear wave elastography. Both the thickness and stiffness in the patient group and controls were compared. The values were also compared with the clinical and demographic profiles of the patients.

Results

DM patients had considerably thicker AT and PF than controls (P < 0.05); mean values of AT thickness for DM patients and controls were 5.66 ± 0.54 mm and 4.61 ± 0.39 mm, respectively, and for PF were 2.53 ± 0.51 mm and 1.97 ± 0.19 mm, respectively. Furthermore, the stiffness of AT and PF was significantly (P < 0.05) lower in DM patients compared to controls, suggestive of softening of AT and PF in Type 2 DM patients. Mean values of shear wave velocity for DM patients and controls in AT were 5.53 ± 0.54 m/s and 7.25 ± 0.61 m/s, respectively, and for PF, 4.53 ± 0.89 m/s and 6.28 ± 0.88 m/s, respectively.

Conclusion

We conclude that there is softening and thickening of the AT and PF in Type 2 DM patients, which can impair foot biomechanics.

Ultrasound Strain Elastography Reliability in the Assessment of the Plantar Fascia and Its Relationship with the Plantar Thickness in Healthy Adults: An Intra and Interobserver Reliability Study in Novice Evaluators

PURPOSE

This study was aimed at verifying both the intraobserver and interobserver reliability of measuring plantar fascia stiffness for a given image in healthy active adults.

METHODOLOGY

This study is reported following the Guidelines of Reporting Reliability and Agreement Studies. A total of 20 plantar fascia from healthy volunteers were analyzed. The thickness of the plantar fascia was measured vertically from the anterior edge of the inferior calcaneal border to the inferior border of the plantar fascia and the ultrasound elastography measurement was taken at the calcaneal insertion of the plantar fascia with the region of interest one centimeter away from the insertion.

RESULTS

The ultrasound strain elastography measurements: the right intraobserver 1 showed an ICC value of 0.9 and the left intraobserver 1 showed an ICC value of 0.78, while the right intraobserver 2 showed an ICC value of 0.91 and the left intraobserver 2 showed an ICC value of 0.83. Interobserver measurements showed excellent reliability with a right ICC value of 0.8 and a left ICC value of 0.9 for the plantar fascia thickness measurements.

DISCUSSION

The results of this study showed a strong correlation between left and right plantar fascia thickness. The intraobserver reliability was excellent for both plantar fascia ultrasound strain elastography and thickness measurements, with interobserver measurements showing excellent reliability.

Infrared Thermography, Intratendon Vascular Resistance, and Echotexture in Athletes with Patellar Tendinopathy: A Cross-Sectional Study

Ultrasonographic signs of tendinopathies are an increase in thickness, loss of alignment in collagen fibers and the presence of neovascularization. Nevertheless, analysis of intratendinous vascular resistance (IVR) can be more useful for understanding the physiological state of the tissue. To show thermal, echotextural, and Doppler signal differences in athletes with patellar tendinopathy and controls. Twenty-six athletes with patellar tendinopathy (PT) participants (30.1 years; SD = 9.0 years) and 27 asymptomatic athletes (23.3 years; SD = 5.38 years) were evaluated with thermographic and Doppler ultrasonography (DS). Area of Doppler signals (DS), echotextural parameters (echointensity and echovariation) and IVR were determined by image analysis. The statistical analysis was performed by Bayesian methods and the results were showed by Bayes Factor (BF10: probability of alternative hypothesis over null hypothesis), and Credibility intervals (CrI) of the effect. The absolute differences of temperature (TD) were clearly greater (BF10 = 19) in the tendinopathy group (patients) than in controls. Regarding temperature differences between the affected and healthy limb, strong evidence was found (BF₁₀ = 14) for a higher temperature (effect = 0.53°C; 95% CrI = 0.15°C-0.95°C) and very strong for reduced IVR compared (BF₁₀ = 71) (effect = -0.67; 95% CrI = -1.10 to 0.25). The differences in area of DS (BF₁₀ = 266) and EV (BF₁₀ = 266) were higher in tendinopathy group. TD showed a moderate positive correlation with VISA-P scores (tau-B = .29; 95% CrI = .04-.51) and strong correlation with IVR (r = -.553; 95%CrI = -.75 to .18). Athletes with patellar tendinopathy showed a more pronounced thermal difference, a larger area of Doppler signal, a lower IVR and a moderately higher echovariaton than controls. The correlation between temperature changes and IVR might be related with the coexistence of degenerative and inflammatory process in PT.

Elasticity evaluation of the plantar fascia: A shear wave elastography study involving 33 early-stage plantar fasciopathy subjects

Background: Plantar fasciopathy, the most common foot condition seen in elderly and athletic populations, can be diagnosed and differentially diagnosed with imaging modalities such as ultrasound shear wave elastography (SWE). However, standard guidelines for ultrasound elastography of the plantar fascia are lacking. The purpose of this study was to determine the impact of the region of interest (ROI) on the evaluation of the plantar fascia elasticity and confirm the screening accuracy of SWE in the early-stage of plantar fasciopathy. Methods: This was an observational case‒control study involving 50 feet of 33 early-stage plantar fasciopathy subjects (the plantar fasciopathy group) and 96 asymptomatic feet of 48 healthy volunteers (the non-pain group). Clinical information, including age, gender, height, weight, visual analogue scale (VAS) score, American Orthopaedic Foot and Ankle Scale score (AOFAS), and the symptom duration, were recorded. All participants underwent both conventional ultrasound and SWE evaluation. The plantar fascia elastic parameters included SWE_single-point, calculated with a single-point ROI set at the greatest thickness of the plantar fascia, and SWE_multi-point, calculated by multipoint ROIs set continuously from the origin at the calcaneus to about 2 cm from the calcaneal origin. Results: The plantar fasciopathy group presented a higher VAS score (median [IQR), 4.00 (3.00) vs. 0.00 (0.00), p < 0.001] and lower AOFAS score [median (IQR), 79.50 (3.00) vs. 100.00 (10.00), p < 0.001] than the non-pain group. The median plantar fascia thickness of the plantar fasciopathy group was significantly greater than that of the non-pain group [median (IQR), 3.95 (1.37) mm vs 2.40 (0.60) mm, p < 0.001]. Abnormal ultrasound features, including echogenicity, border irregularities, and blood flow signals, were more prominent in the plantar fasciopathy group than in the non-pain group (29% vs. 0%, p < 0.001; 26% vs. 1%, p < 0.001; 12% vs. 0%, p < 0.001, respectively). Quantitative analysis of the plantar fascia elasticity revealed that the difference between the value of SWE_single-point and SWE_multipoint was significant [median (IQR), 65.76 (58.58) vs. 57.42 (35.52) kPa, p = 0.02). There was a moderate and significant correlation between the value of SWE_single-point and heel pain. However, there was no correlation between the value of SWE_multipoint and heel pain. Finally, we utilized the results of SWE_single-point as the best elastic parameter reflecting clinical heel pain and found that SWE_single-point could provide additional value in screening early-stage plantar fasciopathy, with an increase in sensitivity from 76% to 92% over conventional ultrasound alone. Additionally, compared with conventional ultrasound and SWE, the use of both improved the accuracy of screening for plantar fasciopathy. Although there were no significant differences in the negative predictive value of conventional ultrasound, SWE, and their combination, the positive predictive value when using both (90.20%) was significantly greater than that when using conventional ultrasound (74.50%) or SWE alone (76.50%). Conclusion: The plantar fascia elastic parameter calculated with single-point ROIs set at the greatest thickness of the plantar fascia is positively correlated with fascia feel pain. Single-point analysis is sufficient for the screening of the early-stage plantar fasciopathy using SWE. SWE_single-point may provide additional valuable information for assessing the severity of plantar fasciopathy.

Presurgical Perspective and Postsurgical Evaluation of the Plantar Fascia

The plantar fascia is an important structure in the foot that acts as a major stabilizer of the longitudinal arch, along with the midfoot ligaments and intrinsic and extrinsic muscles. It is composed predominantly of longitudinally oriented collagen fibers that vary in thickness and are organized into bundles closely associated with the interstitial tissues of the foot. This composition enables the plantar fascia to withstand the weight-bearing forces concentrated on the foot while standing, jumping, walking, or running. This article discusses the normal anatomy and the various pathologies that affect the plantar fascia with an emphasis on presurgical and postoperative appearances on magnetic resonance and ultrasonography imaging.

Ultrasound elastography for the evaluation of plantar fasciitis: A systematic review and meta-analysis

PURPOSE

This meta-analysis aimed to investigate the utility of ultrasound (US) elastography in the assessment of plantar fasciitis (PF).

METHODS

We searched PubMed, Embase, and Scopus and systemically reviewed clinical studies that used US elastography for imaging PF. The primary outcome was the comparison of plantar fascia stiffness between healthy controls and patients with PF, quantified using the weighted mean difference (WMD) and standardized mean difference (SMD).

RESULTS

Eleven studies were included in the final systematic review and meta-analysis. In six studies that employed shear wave elastography, patients with PF had a lower shear wave velocity, with a WMD of -1.772 m/s (95 % confidence interval [CI], -2.663 to -0.880) and an SMD of -1.239 m/s (95 % CI, -1.876 to -0.603), compared to those with asymptomatic heels. One study using the strain ratio showed that the WMD and SMD of patients with diseased heels vs healthy controls were -0.400 (95 % CI, -0.850 to 0.050) and -0.442 (95 % CI, -0.946 to 0.062), respectively. In six articles that use the color histogram of strain elastography, less stiffness was consistently reported in the diseased plantar fascia compared with healthy controls.

CONCLUSION

This meta-analysis showed that the plantar fasciae were less stiff in the PF group than in asymptomatic subjects. The diagnostic performance of US elastography (over B-mode) warrants further investigation.

Medical imaging for plantar heel pain: a systematic review and meta-analysis

Background

Medical imaging can be used to assist with the diagnosis of plantar heel pain. The aim of this study was to synthesise medical imaging features associated with plantar heel pain.

Methods

This systematic review and meta-analysis conducted searches in MEDLINE, CINAHL, SPORTDiscus, Embase and the Cochrane Library from inception to 12th February 2021. Peer-reviewed articles of cross-sectional observational studies written in English that compared medical imaging findings in adult participants with plantar heel pain to control participants without plantar heel pain were included. Study quality and risk of bias was assessed using the National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies. Sensitivity analyses were conducted where appropriate to account for studies that used unblinded assessors.

Results

Forty-two studies (2928 participants) were identified and included in analyses. Only 21% of studies were rated ‘good’ on quality assessment. Imaging features associated with plantar heel pain included a thickened plantar fascia (on ultrasound and MRI), abnormalities of the plantar fascia (on ultrasound and MRI), abnormalities of adjacent tissue such as a thickened loaded plantar heel fat pad (on ultrasound), and a plantar calcaneal spur (on x-ray). In addition, there is some evidence from more than one study that there is increased hyperaemia within the fascia (on power Doppler ultrasound) and abnormalities of bone in the calcaneus (increased uptake on technetium-99 m bone scan and bone marrow oedema on MRI).

Conclusions

People with plantar heel pain are more likely to have a thickened plantar fascia, abnormal plantar fascia tissue, a thicker loaded plantar heel fat pad, and a plantar calcaneal spur. In addition, there is some evidence of hyperaemia within the plantar fascia and abnormalities of the calcaneus. Whilst these medical imaging features may aid with diagnosis, additional high-quality studies investigating medical imaging findings for some of these imaging features would be worthwhile to improve the precision of these findings and determine their clinical relevance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13047-021-00507-2.

Is 2D SWE sufficient as clinical diagnosis in patients with plantar fasciitis?

BACKGROUND

The use of shear wave elastography (SWE) seems to be an important imaging method in the diagnosis of plantar fasciitis (PF).

PURPOSE

To compare patients diagnosed with PF with similar and young healthy control groups in terms of B-mode ultrasound (US) and SWE results and to evaluate the elasticity of the plantar fascia.

MATERIAL AND METHODS

A total of 140 feet of 70 participants were evaluated, including 30 patients and 40 healthy individuals as the control. Clinical, B-mode US, and SWE evaluations were performed for each patient. In addition, American Orthopedic Foot and Ankle Score (AOFAS) was calculated to evaluate pain and foot function in both groups.

RESULTS

Of the patients in the PF group, 40 (88%) were women and the healthy control groups had similar sex distributions (P = 0.23). The AOFAS score was lower in feet with PF compared to the other groups (P < 0.001). Of 30 patients with PF, 15 (50%) had bilateral PF and 15 (50%) unilateral PF. In addition, ≥4 mm thickness measurement, which was used as a diagnostic criterion for PF as a US finding, could be shown in 11 (73.3%) patients with unilateral PF and 6 (40%) patients with bilateral PF.

CONCLUSION

In conclusion, the evaluation of the diagnosis of PF with clinical findings and regular follow-up of measurements with SWE can provide measurement results with higher sensitivity in the diagnosis of PF.

Muscular Echovariation as a New Biomarker for the Classification of Soleus Muscle Pathology: A Cross-Sectional Study

Background: Soleus injury is one of the most common soft tissue tears during sport activities. Current classifications of muscle tears are based on symptoms and tear size and they do not contribute suitable evidence-based treatment protocols. The objective of this study was to analyze the most frequent echotexture findings of patients with soleus muscle injury, located in the central intramuscular tendon (IMT), and healthy people to determine whether they behave differently and to propose an ultrasound (US)-based classification. Methods: eighty-four athletes, who played in sport activities comprising lower limbs. Echotexture characteristics of soleus muscle were reviewed for 84 subjects. They were divided based on the muscle echogenicity in three groups (Injury Type 1 group, Injury type 2 group and healthy group). Echointensity (EI) and Echovariation (EV) were taken in all groups like quantitative US variable. Results. The Injury Type 1 group was identified by a hypoechoic area and characterized by a higher EV; and Injury Type 2 group was identified by a fibrotic area and characterized by a lower EV. The echogenic pattern of healthy people obtained an intermediate value of EV between both injured soleus types. Conclusions. EV may be useful to classify different types of soleus muscle pathology according to the echogenicity pattern. An innovative proposed US-based classification system for soleus tears may be used to guide treatment decisions for patients with central tendon injury of soleus muscle.

Quantitative Ultrasound Changes in Echotexture and Functional Parameters after a Multicomponent Training Program in Pre-Frailty Individuals: A Pilot Randomized Clinical Trial

Objective: Currently, ultrasound imaging (USI) is considered a feasible tool in the evaluation of structural and textural muscle differences due to aging. The main aim of this study was to evaluate sonographic changes in muscular structure and function after a 12-week multicomponent training program in pre-frailty individuals. Design: A prospective, randomized, clinical trial was carried out. Participants: Thirty-two pre-frailty subjects were recruited and randomly divided into a multicomponent training program group (n = 16; Multicomponent group) and a conventional care group (n = 14; Control group) with a 12-week follow up. Main outcome measures: Rectus femoris thickness, cross-sectional area (CSA), echointensity, echovariation and vastus lateralis pennation angle tests were carried out to assess the structure and echotexture, and the force-velocity (F-V) profile for muscle power and muscle strength was employed to assess the functional parameters. Results: Statistically significant differences (p < 0.05) were shown for the left rectus femoris echointensity and in the functional parameter of muscle power after a 12-week program for the multicomponent training group compared to the conventional care group. Conclusions: Pre-frailty elderly subjects showed a decrease in rectus femoris echointensity (RF-EI) and an increase in the functional parameter of muscle power after a 12-week multicomponent training program compared to the control group.

Shear Wave Elastography for Assessment of Muscular Abnormalities Related to Systemic Sclerosis

RATIONALE AND OBJECTIVES

To assess muscular abnormalities related to systemic sclerosis (SSc) using shear wave elastography and correlate results with those of clinical tests.

MATERIALS AND METHODS

We evaluated 55 patients (mean age: 50.4 years; range: 18-88; 34 female) with SSc before treatment and choose muscle groups based on cutaneous involvement and functional impairment [forearms (9); thighs (41); thenar/hypothenar (5)]. We performed shear wave elastography in two orientations to access heterogeneity using virtual touch IQ and mean shear wave velocity values (SWV) and measured skin and fascia thickness. We compared SWVs to the modified Rodnan skin score (mRSS). Twenty-two healthy controls (mean age: 52.0; range: 19-88; 7 female) underwent the same protocol.

RESULTS

SWV pattern analysis (homogeneous vs heterogeneous) detected SSc with sensitivity/specificity/negative predictive value/positive predictive value0.79/0.81/0.91/0.62 in transverse and 0.75/0.18/0.91/0.56 in longitudinal orientation. In patients we found poor correlation between SWVs and mRSS but a cutoff of mRSSE = 20 separated them significantly (p < 0.01). Skin and muscle fascia were significantly thicker in patients vs. controls (p < 0.001).

CONCLUSION

SSc involves more than increased skin and fascial thickness which is not fully represented by mRSS. Elasticity differs in muscles with and without SSc. The former shows higher SWV and increased heterogeneity in transversal planes of muscular fibers.

The Utility of Shear-Wave Elastography in the Evaluation of Myositis

Changes in muscle elasticity are expected in patients with untreated myositis. The purpose of this study was to define the accuracy of shear-wave elastography (SWE) in diagnosing myositis. This case control study included 21 patients (mean age, 49.4 y; 12 women) with myositis who underwent SWE, magnetic resonance imaging (MRI) and biopsy of the involved muscle group. SWE was performed accordingly in a control group (n = 24; mean age, 51.2 y; 8 women). Blood tests consisted of creatine kinase (CK) and aldolase. Two operators performed SWE in longitudinal and transverse planes of muscular fibers, quantifying the mean shear-wave velocity (SWV) and the pattern of stiffness. On MRI, short-TI inversion recovery (STIR) signal hyperintensity and T1 contrast enhancement of muscle was considered diagnostic for myositis. The patient group suffered from different types of myositis (nine patients with polymyositis, eight with dermatomyositis and four with other types of myositis). Blood tests showed significantly increased CK and aldolase values in patients with myositis (p < 0.001 and p < 0.0001). MRI showed a sensitivity of 0.95. In the patient group, the mean SWVs of longitudinal and transverse measurements were 2.8 ± 1.4 m/s and 3.1 ± 1.2 m/s, respectively. In the control group, SWVs were 2.3 ± 0.5 m/s and 2.4 ± 0.5 m/s, respectively. The difference between transverse measurements was significant (p = 0.02). Increased heterogeneity as a marker for myositis in transverse SWE showed a sensitivity of 0.8, specificity of 0.79, positive predictive value (PPV) of 0.76 and negative predictive value (NPV) of 0.82. Inter-observer difference was very low (κ = 0.92). Increased heterogeneity in both planes compared with histologic results showed a sensitivity of 0.56, specificity of 0.93, PPV of 0.91 and NPV of 0.62. Spearman correlation between CK <1000 U/L and SWE was 0.54. In conclusion, transverse orientation SWE may serve as an imaging biomarker for the diagnosis of myositis through the display of a heterogeneous pattern and increased absolute SWV values of inflamed muscles.

Strain Elastography of Injured Equine Superficial Digital Flexor Tendons: A Reliability Study of Manual Measurements

Simple Summary

Strain elastography is an ultrasound-based technique that assesses the mechanical properties of tissues and gives a relative representation of elasticity. Early diagnosis of tendon injuries and long-term monitoring of the healing process are key to equine practice; thus, an accurate method is needed for analyzing and interpreting the images obtained with strain elastography. The first aim of the study was to demonstrate the intraoperator repeatability and interoperator reproducibility of manual measurements of elastograms obtained from injured superficial digital flexor tendons of horses; the second aim was to perform a standardization of the manual measurement method by comparing it with external software. Despite their subjectivity, manual measurements proved to be repeatable and reproducible. In addition, the results obtained with the manual method matched those obtained with the external software.

Abstract

Early diagnosis of tendon injuries and accurate long-term monitoring of the healing process are key for equine veterinarians that use conventional ultrasonography. The development of strain elastography could improve the management of clinical cases. The aim of the study was to assess the intraobserver repeatability and interobserver reproducibility of manual measurements of the colored areas of the tendons within elastograms and to standardize this manual modality by comparing the analysis of the images with ImageJ. Twenty elastograms of the injured superficial digital flexor tendons (SDFTs) of horses were analyzed by two different operators after an acute injury was diagnosed with ultrasonography. Statistical analysis demonstrated excellent intraobserver repeatability (intraclass correlation coefficient, ICC = 0.949) and good interobserver reproducibility (ICC = 0.855) for manual measurements performed with tools available on the ultrasound unit. A good agreement between manual measurements and measurements performed with ImageJ (ICC = 0.849) was then demonstrated. Despite its subjectivity, the manual modality proved to be a valid method for analyzing images obtained with strain elastography.

Ultrasound Imaging Evaluation of Textural Features in Athletes with Soleus Pathology-A Novel Case-Control Study

Background: the aim of this study was to compare the echotexture of patients with soleus muscle injury and age matched controls. Methods: a sample of 62 athletes was recruited at the private clinic and was divided in two group: a healthy group (n = 31) and a soleus pathology group whose athletes had soleus muscle injury, located in the central tendon (n = 31). The muscle thickness (MTh), echointensity (EI) and echovariation (EV) were analyzed. An intra-rater reliability test (Intraclass Correlation Coefficient-ICC) was performed in order to analyze the reliability of the values of the measurements. Results: Sociodemographic variables did not show statistically significant differences (p > 0.05). Ultrasound imaging measurements who reported statistically significant differences were EI (p = 0.001) and standard deviation (SD) (p = 0.001). MTh and EV variables did not show statistically significant differences (p = 0.381 and p = 0.364, respectively). Moreover, reliability values for the MTh (ICC = 0.911), EI (ICC = 0.982), SD (ICC = 0.955) and EV (ICC = 0.963). Based on these results the intra-rater reliability was considered excellent. Conclusion: Athletes with a central tendon injury of soleus muscle showed a lower EI when they were compared to healthy athletes. The echogenicity showed by the quantitative ultrasound imaging measurement may be a more objective parameter for the diagnosis and follow-up the soleus muscle injuries.

A Comparative Study of Treatment Interventions for Patellar Tendinopathy: A Randomized Controlled Trial

OBJECTIVES

To determine the additional effect of dry needling (DN) or percutaneous needle electrolysis (PNE) combined with eccentric exercise (EE) and determine which is the most effective for patients with patellar tendinopathy (PT).

DESIGN

Blinded, randomized controlled trial, with follow-up at 10 and 22 weeks.

SETTINGS

Recruitment was performed in sport clubs. Diagnosis and intervention were conducted at San Jorge University.

PARTICIPANTS

Patients (N=48) with PT with pain for at least 3 months between the ages of 18 and 45 years.

INTERVENTIONS

Three interventions were carried out: DN and EE, PNE and EE, and EE with sham needle as the control group.

MAIN OUTCOME MEASURES

Disability was measured using the Victorian Institute of Sports Assessment Questionnaire, patellar tendon. Visual analog scale was used to measure pain over time, the Short Form-36 was used to measure quality of life, and ultrasound was used to measure structural abnormalities.

RESULTS

A total of 48 participants (42 men, 6 women; average age, 32.46y; SD, 7.14y) were enrolled. The improvement in disability and pain in each group between baseline and post-treatment and baseline and follow-up was significant (P≤.05), without differences among groups.

CONCLUSION

DN or PNE combined with an EE program has not shown to be more effective than a program of only EE to improve disability and pain in patients with PT in the short (10wk) and medium (22wk) terms. Clinical improvements were not associated with structural changes in the tendon.

Quantitative Ultrasound Imaging Differences in Multifidus and Thoracolumbar Fasciae between Athletes with and without Chronic Lumbopelvic Pain: A Case-Control Study

New trends in ultrasound imaging are focused on exploration of morphology and muscle quality. The main goal of the study was to evaluate the first-order descriptor and echostructure of lumbar multifidus at the L4 vertebral level in athletes with and without chronic lumbopelvic pain (CLPP). A case-control study was performed in 15 semiprofessional athletes with CLPP and 15 without (healthy athletes). Lumbar multifidus echointensity and echovariation were measured for muscle quality assessment. Echostructure was used to evaluate lumbar multifidus cross-sectional area (CSA) at resting and during muscle contraction, respective differences during both phases (CSA^Dif.), activation patterns, and thoracolumbar fasciae morphology and thickness. Significant differences with a large effect size were observed in quantitative data from CLPP and healthy athletes for left lumbar multifidus CSA^Dif. and thoracolumbar fasciae morphology. Categorical data showed statistically significant differences with a small-to-moderate effect size for lumbar multifidus activation pattern and thoracolumbar fasciae morphology. Athletes with CLPP showed a reduced CSA difference between lumbar multifidus contraction and at resting and higher disorganization of thoracolumbar fasciae morphology compared to healthy athletes. These findings suggest the importance of dynamic exploration of the lumbar region and connective tissue in sports performance and injury prevention.

Shear Wave Elastography (SWE) for the Evaluation of Patients with Plantar Fasciitis

RATIONALE AND OBJECTIVES

The current imaging standard for diagnosing plantar fasciitis is B-Mode ultrasound (B-US). The aim of this study was to determine the diagnostic potential of Shear Wave Elastography (SWE) and the correlation of clinical scores to elastographic parameters.

MATERIALS AND METHODS

Diagnostic case-control study with n = 82 plantar fascia (PF). PF were divided into three subgroups: (1) symptomatic PF (n = 39); (2) control group of unilateral asymptomatic PF (n = 23); (3) bilateral asymptomatic PF (n = 20). Reference standard for positive findings in B-US was a PF thickness greater than 4 mm. For SWE tissue elasticity (Young's modulus kPa; shear wave speed m/s) was measured at Location 1: directly at the calcaneus; Location 2: +1 cm distal of the calcaneus and Location 3: central part of the calcaneus. Sensitivity, specificity, and diagnostic accuracy as well as correlation to American Orthopaedic Foot and Ankle Score (AOFAS) and Food Functional Index (FFI) were determined.

RESULTS

Symptomatic PF are thicker (4.2 mm, n = 39) than asymptomatic (3.0 mm, n = 43) (p < 0.001). Thickness of the PF (n = 82) correlated poorly to clinical scores (p = 0.001): FFI-pain (r = 0.349); FFI-function (r = 0.381); AOFAS (r = -0.387). Cut-off point for positive SWE finding was 51.5 kPa (4.14 m/s). Symptomatic PF (31.9 kPa, 3.26 m/s, n = 39) differ significantly from asymptomatic PF (93.3 kPa, 5.58 m/s, n = 43) with significant differences at L1 between all groups (p < 0.001). Correlation between Young's modulus (n = 82) and clinical scores was strong (p < 0.001): FFI-pain (r = -0.595); FFI-function (r = -0.567); AOFAS (r = 0.623,). B-US: sensitivity (61%), specificity (95%); SWE sensitivity (85%), specificity (83%). The combination of SWE and B-US increases the sensitivity (100%) with a diagnostic accuracy of 90%.

CONCLUSION

Based on our results, we could show that SWE can improve the diagnostic accuracy in patients with plantar fasciitis compared to B-US.

LEVEL OF EVIDENCE

II.

Sonoelastographic evaluation of plantar fascia after shock wave therapy for recalcitrant plantar fasciitis: A 12-month longitudinal follow-up study

Extracorporeal shockwave therapy (ESWT) is proposed to be effective in reducing pain and improving functional outcome in chronic plantar fasciitis. However, no long-term reports exist on the changes in plantar fascia (PF) elasticity after ESWT. We aimed to evaluate the changes in PF stiffness in patients with plantar fasciitis undergoing ESWT. The visual analogue scale (VAS, 0–100) was used for evaluating heel pain severity. B-mode sonography and strain sonoelastography were used for evaluating the PF thickness and stiffness. The sonoelastogram was analyzed using hue histogram analysis (value: 0–255, from stiffer to softer). All evaluations were recorded before ESWT, and 1 week, 1 month, 3 months, 6 months, and 12 months after ESWT. Repeated measures ANOVA was used to compare pain VAS, PF thickness, and PF hue value at different follow-up time-points. Twenty-two participants (8 men, 14 women) completed all measurements for 12 months. The VAS of heel pain, PF thickness, and PF hue values at pre-ESWT, and 1-week, 1-month, 3-month, 6-month, and 12-month evaluations after ESWT were 62.4 ± 4.2, 49.3 ± 5.8, 38.3 ± 5.7, 27.9 ± 5.3, 18.9 ± 4.7, and 13.2 ± 3.0 (p < 0.01 in all measurements post ESWT versus pre-ESWT); 5.57 ± 0.22 mm, 5.64 ± 0.18 mm, 5.45 ± 0.24 mm, 5.37 ± 0.20 mm, 5.08 ± 0.20 mm, and 4.62 ± 0.15 mm (p < 0.01 at 6-month; otherwise p > 0.05); and 24.5 ± 2.4, 35.2 ± 3.1, 31.0 ± 4.1, 30.5 ± 3.9, 21.4 ± 2.1, and 15.9 ± 1.6 (p < 0.01 at 1-week and 6-month; otherwise p > 0.05), respectively. In conclusion, the heel pain intensity and PF thickness reduced gradually over 12 months after ESWT. The PF stiffness decreased during the first week and increased thereafter; at the 12-month follow-up, stiffness was more than at pre-ESWT.

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.

Ankle and Foot Ultrasound: Reliability of Side-to-Side Comparison of Small Anatomic Structures

OBJECTIVES

In sonography of clinically relevant small structures of the ankle and foot, the healthy contralateral side can be used as a reference to identify subtle abnormalities. Intrasubject side-to-side variability must be minimal. The aim of this study was to assess the reliability of side-to-side sonographic evaluation of small structures of the ankle and foot.

METHODS

Thirty healthy volunteers were prospectively studied. Small structures of the ankle and foot were evaluated bilaterally by 2 musculoskeletal radiologists in separate sessions. The deep peroneal nerve, superior extensor retinacula, calcaneofibular ligament, superior peroneal retinacula, tibialis posterior tendon, tibial nerve, Achilles tendon, plantaris tendon, plantar fascia, and sural nerve were considered. To assess intra- and interreader agreements, 30 (100%) examinations were repeated. A nonparametric statistic was used.

RESULTS

Data were not normally distributed (P > .001). Intrareader agreement was k = 0.67 (95% confidence interval, 0.57-0.78) and interreader agreement was k = 0.73 (95% confidence interval, 0.68-0.77). The mean values and standard deviation for all the structures were 0.36 ± 1.85 mm. The overall coefficient of variation was 18.5%. The intraclass correlation coefficient was 0.93 (95% confidence interval, 0.92-0.94).

CONCLUSIONS

In ankle and foot sonography, the healthy contralateral side can be used as a reference during a real-time musculoskeletal ultrasound evaluation of small structures.

New applications of sonoelastography in rheumatology: where are we now?

Ultrasound elastography (UE) is a non-invasive imaging method that allows the assessment of tissue elastic property. Different UE techniques are currently available (i.e. strain UE and acoustic radiation force impulse UE), with several potential clinical applications. Recent studies investigated the role of UE in two systemic rheumatic diseases and psoriasis. This research added interesting information to the already known applications of UE in the assessment of tendinopathies. In SS, acoustic radiation force impulse UE has shown a potential role in the diagnosis of the disease, with lower sensitivity than and similar specificity to salivary gland histology. In SSc, a potential use of UE in screening pre-clinical disease has been reported. In psoriasis, the use of strain UE in evaluating treatment response has been highlighted. UE is a promising tool in rheumatology, with a potential role in the evaluation of various tissues and pathologies.

Sonoelastography for the Assessment of Muscle Changes in Amyotrophic Lateral Sclerosis: Results of a Pilot Study

The purpose of this study was to assess the sonoelastographic features of four different muscles in patients with amyotrophic lateral sclerosis compared with healthy controls and to evaluate the relationship of these features to muscle strength and other ultrasonographic variables. Fourteen patients with amyotrophic lateral sclerosis and 20 controls were examined using strain sonoelastography scanning. The RGB channel fraction ratio was analyzed with ImageJ software (Version 1.48). Two main sonoelastographic patterns could be distinguished in the controls: a clear predominance of the blue channel (hard areas) and a more heterogeneous pattern with predominance of the green channel (intermediate stiffness). These patterns were also observed in patients, although a higher green channel score was observed in mildly impaired muscles, whereas a higher blue channel score was observed in the most severely impaired muscle. Sonoelastography may be a good complementary biomarker in the detection and monitoring of muscle changes in amyotrophic lateral sclerosis.

Quantitative Muscle Ultrasonography Using Textural Analysis in Amyotrophic Lateral Sclerosis

The purpose of this study was to analyze differences in gray-level co-occurrence matrix (GLCM) parameters, as assessed by muscle ultrasound (MUS), between amyotrophic lateral sclerosis (ALS) patients and healthy controls, and to compare the diagnostic accuracy of these GLCM parameters with first-order MUS parameters (echointensity [EI], echovariation [EV], and muscle thickness [MTh]) in different muscle groups. Twenty-six patients with ALS and 26 healthy subjects underwent bilateral and transverse ultrasound of the biceps/brachialis, forearm flexor, quadriceps femoris, and tibialis anterior muscle groups. MTh was measured with electronic calipers, and EI, EV, and GLCM were obtained using Image J (v.1.48) software. Sensitivity, specificity, likelihood ratios, and area under the curve (AUC) were performed by logistic regression models and receiver operating characteristic curves. GLCM parameters showed reduced granularity in the muscles of ALS patients compared with the controls. Regarding the discrimination capacity, the best single diagnostic parameter in forearm flexors and quadriceps was GLCM and in biceps brachialis and tibialis anterior was EV. The respective combination of these two parameters with MTh resulted in the best AUC (over 90% in all muscle groups and close to the maximum combination model). The use of new textural parameters (EV and GLCM) combined with usual quantitative MUS variables is a promising biomarker in ALS.

Muscular Echovariation: A New Biomarker in Amyotrophic Lateral Sclerosis

The purpose of the work described here was to assess the characteristics of echovariation in amyotrophic lateral sclerosis (ALS) compared with other muscle ultrasonography parameters. Twenty-six ALS patients (8 women, mean age 58.9 y, standard deviation 12.02 y) and 26 healthy controls (17 women, mean age 59.6 y, standard deviation 6.41 y) were included in this observational study. They underwent bilateral and transverse ultrasound of the biceps/brachialis, forearm flexor group, quadriceps femoris and tibialis anterior. Muscular thickness, echo-intensity and echovariation were analyzed. Muscles affected by ALS had increased echo-intensity, decreased thickness and decreased echovariation. Echovariation in all muscles except the quadriceps femoris strongly correlated with muscle strength (explained variance between 21.8% in the biceps/brachialis and 37.5% in the tibialis anterior) and the ALS Functional Rating Scale Revised score (explained variance between 26% in the biceps/brachialis and 36.7% in the forearm flexor group). Echovariation is an easy-to-obtain quantitative muscle ultrasonography parameter that could distinguish ALS patients from healthy controls more accurately than previous described biomarkers.

Ultrasound measures of tendon thickness: Intra-rater, Inter-rater and Inter-machine reliability

BACKGROUND

Ultrasound imaging is often used by physiotherapists and other healthcare professionals but the reliability of image acquisition with different ultrasound machines is unknown. The objective was to compare the intra-rater, inter-rater and intermachine reliability of thickness measurements of the plantar fascia (PF), Achilles tendon (AT), patellar tendon (PT) and elbow common extensor tendon (ECET) with musculoskeletal ultrasound imaging (MSUS).

METHODS

Tendon thickness was measured in four anatomical structures (14 participants, 28 images per tendon) by two sonographers and with two different ultrasound machines. Intraclass Correlation Coefficients (ICCs) and Bland-Altman plots were calculated. The standard error of measurement (SEM) and minimum detectable difference (MDD) were calculated.

RESULTS

Inter-rater reliability was excellent for AT (ICC=0.98; 95% CI= 0.96-0.99) and very good for PT (ICC=0.85; 95% CI = 0.67-0.93) and ECET (ICC=0.81; 95% CI= 0.72-0.94). Reliability for PF was moderate, with an ICC of 0.63 (CI 95%= 0.20-0.83). Bland-Altman plot for inter-machine reliability showed a mean difference of 1 m for PF measurements and a mean difference of 4 m and 20 m for AT and PT. The relative SEMs were below 7% and the MDCs were below 0.7 mm.

CONCLUSION

The MSUS reliability in measuring thickness of the four tendons is confirmed by the homogeneous readings intra sonographers, between operators and between different machines. Level of evidence: Tendon thickness can be measured reliably on different ultrasound devices, which is an important step forward in the use of this technique in daily clinical practice and research.

LEVEL OF EVIDENCE

III.

Plantar fasciitis in athletes: diagnostic and treatment strategies. A systematic review

BACKGROUND

Plantar fasciitis (PF) is reported in different sports mainly in running and soccer athletes. Purpose of this study is to conduct a systematic review of published literature concerning the diagnosis and treatment of PF in both recreational and élite athletes. The review was conducted and reported in accordance with the PRISMA statement.

METHODS

The following electronic databases were searched: PubMed, Cochrane Library and Scopus. As far as PF diagnosis, we investigated the electronic databases from January 2006 to June 2016, whereas in considering treatments all data in literature were investigated.

RESULTS

For both diagnosis and treatment, 17 studies matched inclusion criteria. The results have highlighted that the most frequently used diagnostic techniques were Ultrasonography and Magnetic Resonance Imaging. Conventional, complementary, and alternative treatment approaches were assessed.

CONCLUSIONS

In reviewing literature, we were unable to find any specific diagnostic algorithm for PF in athletes, due to the fact that no different diagnostic strategies were used for athletes and non-athletes. As for treatment, a few literature data are available and it makes difficult to suggest practice guidelines. Specific studies are necessary to define the best treatment algorithm for both recreational and élite athletes.

LEVEL OF EVIDENCE

Ib.

Sonoelastography in the Evaluation of Plantar Fasciitis Treatment: 3-Month Follow-Up After Collagen Injection

OBJECTIVE

The aim of this study was to investigate whether ultrasound elastography can demonstrate the outcome of the treatment in comparison with gray-scale imaging.

METHODS

Sixteen patients (mean age, 46.9 years) with plantar fasciitis were prospectively enrolled after unsuccessful conservative treatment. Individuals graded their heel pain on a 100-mm visual analogue scale (VAS) and underwent gray-scale ultrasonography and sonoelastography. Collagen was injected in the heels. Fascial thickness and hypoechogenicity, perifascial edema, and plantar fascial elasticity were evaluated. Follow-up sonoelastography and VAS grading were done 3 months after the injection. Statistical analyses were performed by the paired t test and the Fisher exact test. A P < 0.05 was considered statistically significant.

RESULTS

Mean plantar fascial thickness showed insignificant decrease on follow-up (from 4.30 [1.37] to 4.23 [1.15] mm, P = 0.662). Fascial hypoechogenicity and perifascial edema did not change significantly after treatment. The mean strain ratio of the plantar fascia was significantly increased (from 0.71 [0.24] to 1.66 [0.72], P = 0.001). Softening of the plantar fascia decreased significantly after injection (from 12 to 3 ft, P = 0.004). Twelve (75%) of 16 patients showed significant VAS improvement at the follow-up.

CONCLUSIONS

Sonoelastography revealed a hardening of the plantar fascia after collagen injection treatment and could aid in monitoring the improvement of the symptoms of plantar fasciitis, in cases where gray-scale imaging is inconclusive.

Serial Changes of Tendon Histomorphology and Strain Elastography After Induced Achilles Tendinopathy in Rabbits: An In Vivo Study

OBJECTIVES

The purpose of this study was to investigate and compare the serial changes of morphology and strain in the early process of Achilles tendinopathy in a rabbit model.

METHODS

A total of 10 New Zealand white rabbits underwent ligation of one of their Achilles tendons to induce ischemic injury. Both inflamed and contralateral Achilles tendons were serially evaluated with 3 follow-ups: the first on days 3 to 5, the second on days 9 to 13, and the third and last follow-up on days 15 to 20 after surgery. During each examination, tendon thickness was measured and red, green, and blue pixel intensities of the elastogram were analyzed using color histogram analysis software. Differences between the inflamed and control group were compared.

RESULTS

The mean thickness of the inflamed tendons increased during consecutive follow-ups and was significantly larger than that of control tendons (P < .01). The mean red pixel intensity ratio of the inflamed tendons was also serially increased and was higher than that in the control tendons, indicating softening. However, the difference was significant only in the second and third follow-ups (P < .01).

CONCLUSIONS

Tendon thickening and softening developed during the early process of Achilles tendinopathy in a rabbit model. Tendon softening may present later than thickening.

Imaging of plantar fascia disorders: findings on plain radiography, ultrasound and magnetic resonance imaging

Plantar fascia (PF) disorders commonly cause heel pain and disability in the general population. Imaging is often required to confirm diagnosis. This review article aims to provide simple and systematic guidelines for imaging assessment of PF disease, focussing on key findings detectable on plain radiography, ultrasound and magnetic resonance imaging (MRI). Sonographic characteristics of plantar fasciitis include PF thickening, loss of fibrillar structure, perifascial collections, calcifications and hyperaemia on Doppler imaging. Thickening and signal changes in the PF as well as oedema of adjacent soft tissues and bone marrow can be assessed on MRI. Radiographic findings of plantar fasciitis include PF thickening, cortical irregularities and abnormalities in the fat pad located deep below the PF. Plantar fibromatosis appears as well-demarcated, nodular thickenings that are iso-hypoechoic on ultrasound and show low-signal intensity on MRI. PF tears present with partial or complete fibre interruption on both ultrasound and MRI. Imaging description of further PF disorders, including xanthoma, diabetic fascial disease, foreign-body reactions and plantar infections, is detailed in the main text. Ultrasound and MRI should be considered as first- and second-line modalities for assessment of PF disorders, respectively. Indirect findings of PF disease can be ruled out on plain radiography.

Teaching Points

• PF disorders commonly cause heel pain and disability in the general population.

• Imaging is often required to confirm diagnosis or reveal concomitant injuries.

• Ultrasound and MRI respectively represent the first- and second-line modalities for diagnosis.

• Indirect findings of PF disease can be ruled out on plain radiography.