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

Asymptomatic sonographic abnormalities of the hindfoot region in Division I collegiate gymnasts

BACKGROUND

The hindfoot region is commonly injured in gymnasts, and musculoskeletal ultrasound can be used to identify structural abnormalities in this region. Although prior studies have shown that sonographic abnormalities may not correlate with symptomatic pathology, the presence of asymptomatic sonographic abnormalities of the hindfoot in Division I collegiate gymnasts has not been evaluated.

OBJECTIVE

To identify and describe commonly seen asymptomatic sonographic abnormalities of the hindfoot region in Division I collegiate gymnasts.

DESIGN

Cross-sectional study.

SETTING

Tertiary care academic medical center.

PARTICIPANTS

39 Division I NCAA men's and women's collegiate gymnasts without current hindfoot pain or history of hindfoot injury.

INTERVENTIONS

Diagnostic musculoskeletal ultrasound of the hindfoot region.

MAIN OUTCOME MEASURES

Sonographic appearance of the hindfoot region, specifically the plantar fascia, plantar fad pad, and Achilles tendon.

RESULTS

A total of 37 of 39 gymnasts included in the study were found to have at least one asymptomatic sonographic abnormality of the hindfoot region. A total of 28.2% of athletes were found to have sonographic abnormalities within the Achilles tendon, with Doppler flow being the most common finding, and 35.8% of athletes were found to have a Haglund's deformity. However, only 7% of athletes with a Haglund's deformity demonstrated abnormal sonographic findings within the tendon. Sonographic abnormalities of the plantar fascia and plantar fat pad were seen in 30.7% and 69.2% of athletes, respectively.

CONCLUSIONS

Asymptomatic sonographic abnormalities of the hindfoot region are common in collegiate gymnasts. Clinicians should use clinical judgment when interpreting these findings as they may not represent symptomatic pathology.

Utility of Shear Wave Elastography for the Diagnosis of Plantar Fasciitis: Comparison Between Symptomatic and Asymptomatic Sides in Unilaterally Affected Patients

INTRODUCTION

Plantar fasciitis (PF) can cause pain in the heel, which can affect everyday activities. While it often resolves on its own, diagnosing PF to rule out other hind foot conditions by imaging modality in cases of recurrence can be difficult. Methods such as MRI and ultrasonography are helpful, but the use of elastography, specifically shear wave elastography (SWE), as a tool for diagnosing PF is being studied.

METHODOLOGY

This comparative observational study included patients over 18 years presenting with unilateral hind foot pain who were investigated using SWE. Exclusions comprised those who were bilaterally affected and with foot deformities, trauma history, or prior injection therapy. Patients' AOFAS Ankle-Hindfoot Scores were assessed along with visual analog scale (VAS) scores, followed by SWE examination of both heels.

RESULTS

The study found no significant difference in the plantar fascia thickness between affected and unaffected sides, with a mean thickness of 4.3±0.8mm and 5.1±0.6mm, respectively. Shear wave velocity (SWV) was lower on the affected side, indicating reduced stiffness compared to the unaffected side. The Spearman rank test revealed strong direct correlations between SWV and both the VAS and HF-AOFAS scores on the affected side.

CONCLUSION

The study observed that SWE enhances B-mode ultrasonography in detecting early PF even with normal plantar fascia thickness, offering a user-independent and reliable tool for treatment monitoring and correlation with functional and pain scores. Further research with larger populations can aid in developing a clinico-radiological classification system for PF, improving prognostication and treatment guidance.

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.

Myofascial stiffness of plantar fascia and Achilles tendon in individuals with plantar fasciopathy: An observational cross-sectional study

BACKGROUND

Assessment of myofascial tissue stiffness have a role in identifying physical impairments in plantar fasciopathy (PF). It is still unclear which specific functional and tissue differences exist between individuals with PF.

AIM

To compare myofascial stiffness of plantar fascia, Achilles tendon, and triceps surae between symptomatic and asymptomatic limbs in individuals with PF and between individuals with and without PF.

METHODS

Thirty nine individuals diagnosed with PF and individuals with no history of PF were recruited. Myofascial stiffness of the plantar fascia, Achilles tendon, and triceps surae, range of motion, and clinical tests were performed. Mean difference (MD) and 95% confidence interval (CI) were calculated.

RESULTS

Individuals with PF showed lower mean stiffness in Achilles tendon insertion (MD = -1.00 N/mm; 95%CI: -1.80,-0.21) on the symptomatic limb compared to the corresponding symptomatic limb in control group, a lower mean stiffness in plantar fascia (MD = -0.16 N/mm; 95%CI: -0.30, -0.01) on the symptomatic limb compared to asymptomatic limb, and a lower mean stiffness in the region 3 cm above the Achilles tendon insertion (MD = -0.79; 95%CI: -1.59, -0.00) compared to control. Individuals with PF showed fewer repetitions in heel rise test (MD = -3.97 reps; 95%CI: -5.83, -2.12) and in the step-down test (MD = -5.23 reps; 95%CI: -7.02, -3.44) compared to control.

CONCLUSIONS

Individuals with PF present reduced stiffness in Achilles tendon insertion and plantar fascia. The reduced stiffness was more evident in Achilles tendon in individuals with PF compared to individuals without PF. Individuals with PF showed lower performance in clinical tests.

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.

Role of shear wave elastography in the diagnostic evaluation of plantar fasciitis: a prospective case-control study

OBJECTIVES

To assess the advantage of the addition of shear wave elastography (SWE) to gray-scale sonography in the diagnosis of plantar fasciitis.

METHODS

30 subjects between 18-60 years of age with unilateral heel pain who were clinically suspected of having plantar fasciitis were included in this study. Their affected feet were taken as cases; while their contralateral feet served as controls. On gray-scale ultrasound, the thickness of plantar fascia, its echopattern, presence of hypoechoic areas, and perifasicular collections were recorded. SWE was done by placing seven ROIs within the plantar fascia; and the mean of their Young's modulus was taken in kPa.

RESULTS

Plantar fascial thickening more than 4 mm had 70% sensitivity and 66.7% specificity, echopattern had 90% sensitivity and 96.7% specificity, hypoechoic areas had 80% sensitivity and 96.7% specificity, and perifascial edema had 26.7% sensitivity and 100% specificity for diagnosing plantar fasciitis. Using the ROC curve, the cut-off value of Young's modulus for the diagnosis of plantar fasciitis was found to be ≤ 99.286 kPa. This predicted plantar fasciitis with 97% sensitivity and 100% specificity. The primary diagnostic feature of ultrasound of plantar fascia thickness more than 4 mm detected 21 out of 30 cases of plantar fasciitis; whereas elastography detected an additional 8 cases which would have been missed on B-mode ultrasound alone.

CONCLUSIONS

SWE is a useful supplement and improves the diagnostic accuracy of gray-scale ultrasound in plantar fasciitis.

An assessment of plantar fascia with ultrasound findings in patients with plantar fasciitis: a systematic review

INTRODUCTION

Plantar fasciitis (PFS) is described by an intense pain over medial tubercle of calcaneus, increased with the first step after waking up, after rest and during weightbearing activity. It is the most common cause of plantar heel pain in adults with the prevalence estimated 10% of the general population. Ultrasound imaging is commonly being used to measure the PF thickness, evaluate the efficacy of different treatments and a guide therapeutic technique in patients with PFS. The objective of this study was to systematically review the studies that were previously published to evaluate the role of ultrasound in the assessment of PF in patients with PFS.

METHODS

A systematic search was carried out over the last 5 years from 2017 to 2022 on basis the following electronic databases: Science Direct, Scopus, Web of Science, Springer and PubMed. The keywords that used in the searching were: ultrasound, sonography, ultrasonography, plantar fasciitis, imaging of plantar fascia, physiotherapy of plantar fasciitis, interventional treatment of plantar fasciitis, randomized controlled trial of plantar fasciitis and interventional ultrasound. The review focused on the assessment of PF in patients with PFS underwent different interventions using B-mode, shear wave elastography (SWE) and color Doppler ultrasound.

RESULTS

During the search process, 1661 were recorded using the proper keywords from 2017 to 2022 in which 666 original articles were found after removing the review and duplicated articles. Of these, thirty articles met the inclusion criteria and included in this review. The articles have assessed the PF in patients with PFS under different conditions using different ultrasound modes. Twenty-six articles evaluated the effectiveness of different treatment on PF in patients with PFS using different ultrasound modes. In 8 of 26 articles, the ultrasound was used as both an assessment tool of PF and guide therapeutic technique in patients with PFS. In 18 articles, the ultrasound was used as only assessment tool to identify the PF thickness and its observation changes in patients with PFS. Four articles compared the PF thickness and its intrafascial changes between patients with PFS and healthy subjects.

CONCLUSION

The ultrasound can be a reliable tool in assessment the effect of different interventions on PF by evaluating its thickness, echogenicity and stiffness changes in patients with PFS. There were different methods and treatments were used among the studies.

Shear-wave elastography of the plantar fascia: a systematic review and meta-analysis

PURPOSE

To assess the efficacy of shear-wave elastography (SWE) of the plantar fascia (PF) in identifying plantar fasciitis.

METHODS

A literature search was conducted on the PubMed and Medline databases for articles published up to August 2022. The Newcastle-Ottawa scale was used to assess the risk of bias. We included original research studies in English dealing with the evaluation of patients with plantar fasciitis by means of SWE and including shear modulus (KPa) and/or shear-wave velocity (m/s). We compared healthy and pathologic PF stiffness using the standardised mean difference (SMD) in a random-effects model (95% CI).

RESULTS

Five studies were included with a total of 158 pathologic PFs and 134 healthy PFs. No significant publication bias was detected. Studies were highly heterogeneous (p < 0.00001; I² = 97%). Pathologic PFs showed significantly lower stiffness, with an SMD of - 3.00 m/s (95% confidence interval: - 4.95 to - 1.06, p = 0.002), compared to healthy PF.

CONCLUSION

Pathologic PFs present significantly lower stiffness than healthy PFs. However, the analysed studies are highly heterogeneous.

Effect of plantar fascia-specific stretching and Achilles tendon stretching on shear wave elasticity of the plantar fascia in healthy subjects

BACKGROUND

The effect of stretching on the mechanical properties of the plantar fascia (PF) remain unclear. This study was performed to determine the effect of PF-specific stretching (PFSS) and Achilles tendon stretching (ATS) on the viscoelastic properties of the PF with shear wave elastography (SWE).

METHODS

We recruited 14 participants (8 men, 6 women) with no history of PF disorders or painful episodes. The mean age of the participants was 30.9 ± 4.8 (range, 25-41) years. All participants performed sustained PFSS (sPFSS) on one foot and intermittent PFSS (iPFSS) on the other foot. Two weeks later, all participants performed sustained ATS (sATS) on one foot and intermittent ATS (iATS) on the other foot. SWE measurements were performed immediately after each stretching.

RESULTS

The PF elasticity immediately before stretching ranged from 133.8 kPa to 144.7 kPa. The PF elasticity after stretching ranged from 158.9 kPa to 215.8 kPa. There was a significant increase in PF elasticity after sPFSS, iPFSS, sATS, and iATS (P < .01). The elasticity after sATS was greater than that after iATS (P = .03). In contrast, there were no differences in PF elasticity after stretching between sPFSS and iPFSS (P = .13), sPFSS and sATS (P = .17), or iPFSS and iATS (P = .50).

CONCLUSIONS

PF elasticity increased after stretching regardless of the frequency and type of PFSS and ATS.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

A shear-wave sonoelastography investigation of calf muscle pump biomechanics in patients with chronic venous disease and healthy controls

BACKGROUND

chronic venous disease (CVD) is a common progressive disorder with incompetence of calf muscle pump due to weakness and ankle mobility abnormality is an important etiological factor in CVD, but the biomechanical properties of calf muscle pump are remain unknown.

OBJECTIVES

The purpose of the present study was to evaluate group differences between the biomechanical properties changes of the medial gastrocnemius muscle (GM) and its fascias in participants with CVD and healthy controls.

METHODS

In this case-control study, thirty patients with CVD in three equal groups (mild: C1 - C2, moderate: C3 - C4, severe: C5 - C6) and 20 healthy subjects in a control group participated. The medial GM and its fascias shear modulus (stiffness) were measured using a shear-wave sonoelastography in rest and active dorsiflexion positions of ankle joint.

RESULTS

The results of variance (ANOVA) analysis showed a significant difference in shear wave elastography (SWE) value between the groups for medial GM and its fascias at rest and active dorsiflexion of the ankle joint (P < 0.05). There was a statistically significant increase in SWE value of the medial GM and its fascias in moderate (c3-c4) and severe CVD groups (C5-C6) compared to the control and mild (C1-C2) CVD groups. A positive correlation was discovered between disease grades and the medial GM and its fascias SWE in patients with CVD ranging between r = 0.846 to 0.891; P < 0.001.

CONCLUSION

An alteration stiffness in calf myofascial pump as compared to control group indicated an impaired myofascial biomechanics. Calf myofascial SWE may be valuable information in the diagnosis and follow-up processes of patients with CVD.

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.

Quantification of the in vivo stiffness and natural length of the human plantar aponeurosis during quiet standing using ultrasound elastography

This study aimed to identify the stiffness and natural length of the human plantar aponeurosis (PA) during quiet standing using ultrasound shear wave elastography. The shear wave velocity (SWV) of the PA in young healthy males and females (10 participants each) was measured by placing a probe in a hole in the floor plate. The change in the SWV with the passive dorsiflexion of the metatarsophalangeal (MP) joint was measured. The Young's modulus of the PA was estimated to be 64.7 ± 9.4 kPa, which exponentially increased with MP joint dorsiflexion. The PA was estimated to have the natural length when the MP joint was plantarflexed by 13.8°, indicating that the PA is stretched by arch compression during standing. However, the present study demonstrated that the estimated stiffness for the natural length in quiet standing was significantly larger than that in the unloaded condition, revealing that the PA during standing is stiffened by elongation and through the possible activation of intrinsic muscles. Such quantitative information possibly contributes to the detailed biomechanical modeling of the human foot, facilitating an improved understanding of the mechanical functions and pathogenetic mechanisms of the PA during movements.

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.

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.

Intraobserver Assessment of Shear Wave Elastography in Tensor Fasciae Latae and Gluteus Maximus Muscle: The Importance of the Hip Abductor Muscles in Runners Knee Compared to Healthy Controls

Background: Iliotibial band syndrome (ITBS) represents one of the most common running related injuries. The pathophysiology is postulated to be caused by excessive ITB tension, impingement and irritation of soft tissues at the lateral femoral epicondyle. However, direct evidence has yet to be found and the multifactorial etiology is under discussion. The purpose was to evaluate stiffness of ITB, gluteus maximus (GM) and tensor fasciae latae (TFL) muscles using shear wave elastography (SWE). Methods: In 14 patients with clinically verified ITBS and 14 healthy controls, three SWE measurements each of ITB, GM and TFL in both legs was performed to determine measurement reliability and between-group and -leg differences. Results: The mean value of ITB was 12.8 m/s with ICC of 0.76, whereas the values measured in the GM were 3.02 m/s with an ICC of 0.87. No statistically significant difference in controls compared to patients were found (p = 0.62). The mean value of TFL was 5.42 m/s in healthy participants, compared to 3.89 m/s patients with an ICC of 0.98 (p = 0.002). Conclusion: Although SWE showed no difference in ITB stiffness, significant differences for TFL muscle stiffness in runner’s knee was found, suggesting that the hip abductor muscles might play a bigger role in the pathophysiology of ITBS. We aimed to implement baseline values for stiffness assessments and prove reliability for further prospective studies of SWE in runner’s knee.

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.

Shear Wave Elastography of the Plantar Fascia: Comparison between Patients with Plantar Fasciitis and Healthy Control Subjects

Background: The purpose of this study was to evaluate plantar fasciae of healthy subjects and patients with plantar fasciitis by shear wave velocity (SWV) and stiffness with correlation to B-Mode and color Doppler ultrasonography (CDUS) and to establish cut-off values. Methods: This observational study was conducted with the approval of the Institutional Review Boards (IRBs) of our institution. 108 unilateral plantar fasciae were evaluated by including 87 consecutive patients (mean age 51.7; range: 29–82) (66 women and 21 men) with plantar fasciitis and 21 asymptomatic age matched healthy volunteers (mean age 47.3; range: 32–58) (15 women and 6 men). All patients were prospectively imaged between July 2018 and March 2019. B-mode US was used to measure thickness and CDUS to grade vascularity. SWE measurements were repeated 3 times and mean was used for statistical analysis. Results: Mean SWV value in healthy subjects was 6.94 m/s and in patients 4.98 m/s with a mean stiffness value of 152.88 kPa and 93.54 kPa respectively (p < 0.001). For SWV a cut-off value of 6.16 m/s had a specificity of 80.95% and sensitivity of 79.31%. For stiffness a cut-off value of 125.57 kPa had a specificity of 80.95% and sensitivity of 80.46%. No correlation to CDUS was found. The mean thickness of healthy fascias was 3.3 mm (range 2.4–3.9) compared to 6.1 mm (range 2.0–22.0) in plantar fasciitis (p < 0.001) with no correlation to SWV or to stiffness (r² = 0.02, p = 0.06). Conclusion: SWE allows quantitative assessment of plantar fascia stiffness, which decreases in patients with plantar fasciitis. No correlation to the thickness of the plantar fascia was found, therefore it represents an independent factor for the diagnosis of plantar fasciitis and could be helpful in addition to thickness measurement in unclear cases.

Shear wave elastography for treatment monitoring of plantar fasciitis

BACKGROUND

Plantar fasciitis is a common cause of heel pain. Monitoring therapy effects is challenging with conventional B-mode ultrasound. Shear wave elastography (SWE) provides important diagnostic information beyond B-mode, with typically lower tissue stiffness in symptomatic plantar fascia. Up to now little is known about SWE features for therapy monitoring in plantar fasciitis. We evaluated the clinical effects of a 3-month physical therapy based treatment and its influence on B-mode and SWE ultrasound findings in patients suffering from plantar fasciitis, correlating ultrasound findings to score-based symptom development.

METHODS

Prospective, IRB-approved clinical study in plantar fasciitis patients undergoing a 3-month physical therapy based treatment. Measurement time points were before (T0), after 1 (T1) and 3 (T2) months of treatment, consisting of clinical orthopedic (FFI, AOFAS-Score) and multimodal radiologic sonographic examinations (B-mode/SWE) using a high-resolution linear 18-MHz probe.

RESULTS

A total of 33 patients with 43 symptomatic plantar fascia were included. We found a significant (P<0.001) clinical score improvement (AOFAS +14, FFI-Pain -21, FFI-Function -18) between T0 and T2. Mean initial thickness (T0) of symptomatic plantar fascia was 4.2 (±1.2) mm, compared to 3.2 (±0.7) mm at the asymptomatic contralateral side (P<0.001). No significant thickness changes were seen at T1 (4.2±1.1 mm) and T2 (4.5±1.3 mm), even though clinical scores improved significantly. Mean initial stiffness (T0) of symptomatic plantar fascia was 59.57 (±43.3) kPa, compared to 83.23 (±47.3) kPa at the asymptomatic contralateral side (P<0.001). In contrast to B-mode ultrasound, SWE values increased significantly between T0 (59.6±43.3 kPa), T1 (82.6±47.3 kPa) and T2 (102.5±47.2 kPa) (P<0.001-0.009), with positive correlations for AOFAS/FFI-Pain/Function scores (r=0.285-0.473, P<0.001-0.002).

CONCLUSIONS

A physical therapy based treatment relieves plantar fasciitis symptoms during a 3-month period. In line with symptom reduction, stiffness (Young's-moduli) of plantar fascia increased significantly, while B-mode ultrasound revealed no measurable changes during the healing process. Shear wave elastography was able to quantify plantar fascia pathologies and their recovery under therapy.

Evaluation of plantar fascia using high-resolution ultrasonography in clinically diagnosed cases of plantar fasciitis

Purpose

The aim of this study was to assess the efficacy of high-resolution ultrasonography in the assessment of plantar fascia in individuals with heel pain, before and after treatment.

Material and methods

This study was conducted from 2016 to 2019, during which time 44 clinically diagnosed patients of plantar fasciitis were compared to 50 normal volunteers. There were 25 males and 25 females in the control group and 42 females and two males in the study group. Thirty-eight patients had unilateral disease, and six patients had bilateral disease. The thickness of the plantar fascia was measured just anterior to its calcaneal attachment using ultrasonography. Body mass index (BMI) was also calculated in both groups.

Results

The plantar fascia was 2-4 mm thick in the control group whereas it was > 4 mm thick in 48 heels in the study group. With cut-off of > 4 mm as diagnostic of plantar fasciitis, this study had a sensitivity of 96%, specificity of 100%, and accuracy of 98%. BMI was increased in 60% of female patients. All patients were treated with local infiltration of corticosteroid. In 37/42 patients (43 heels) who had improved clinically, the thickness of plantar fascia was reduced to < 4 mm when assessed after six weeks of corticosteroid injection.

Conclusions

Diagnosis of plantar fasciitis can be easily verified by ultrasonography with plantar fascia thickness > 4 mm being suggestive of plantar fasciitis. Ultrasound can also be used to evaluate treatment response. Ultrasono-graphy helps the clinician in confirming the diagnosis of plantar fasciitis and also in assessing the response to treatment.

Evaluation of plantar fasciopathy shear wave elastography: a comparison between patients and healthy subjects

PURPOSE

The aim of this study is to compare elasticity features between patients with plantar fasciitis (PFis) and an asymptomatic healthy control group using shear wave elastography (SWE) and to correlate SWE values with clinical scores.

METHODS

Consecutive patients diagnosed with PFis and asymptomatic subjects were enrolled in the present study. Both groups underwent clinical, ultrasound (US), and SWE evaluation. A plantar fascia thickness > 4 mm was considered pathognomonic of PFis. SWE stiffness elasticity (Young's modulus in kPa and shear wave velocity in m/s) was measured 1 cm distally from the calcaneal insertion. Correlations with VAS and the 17-Italian Foot Function Index (17-FFI) were determined.

RESULTS

A total of 19 patients satisfied the inclusion criteria for the patient group and were enrolled in the study, and 21 healthy subjects were used as a control group. Statistically significant differences were found for shear wave velocity between the patient and the control group, with SWE findings of 3.8 (5.1; 1.5) m/s and 4.7 (4.07; 7.04) m/s, respectively (p = 0.006). Strong positive correlations were found between the SWE findings and both the pain and the functional scale (VAS: p = 0.001; FFI: p = 0.012).

CONCLUSION

SWE allows quantitative assessment of the stiffness of the plantar fascia and can show PFis alterations, increasing the diagnostic performance of B-mode US. In addition, SWE shows a strong correlation with clinical scores, improving patient assessment and follow-up.

Measurement of intrinsic foot stiffness in minimally and traditionally shod runners using ultrasound elastography: A pilot study

Running is an activity with a consistently high injury rate. Running footwear design that mimics barefoot running has been proposed to reduce injury rate by increasing the strength of foot structures. However, there is little evidence to support this. The purpose of the current study is to use shear wave ultrasound elastography to examine material properties (shear modulus) of intrinsic foot structures in experienced minimally and traditionally shod runners. It is hypothesized that minimalist runners will exhibit increased stiffness compared to controls demonstrating the strengthening of these structures. Eighteen healthy runners (8 minimalist and 10 traditionalist), running a minimum of 10 mi · wk^-1, participated. Elastography scans were performed on the left foot of each participant. There is no apparent stiffening of foot structures associated with wearing minimalist shoes. Only the FHB tendon is different between shoe types and, contrary to the hypothesis, was stiffer in traditionalist compared to minimalist runners (257.26 ± 51.64 kPa vs 160.88 ± 27.79 kPa, respectively). A moderate positive (r = 0.7) relationship between training load and tendon stiffness suggests strengthening of tendon when running in traditional shoes. If running in minimalist shoes increases loading on these structures without resulting in stronger tissues, it is possible that minimalist footwear may increase injury risk.