Mapping tendon stiffness: Two-dimensional versus point shear wave elastography

Mario Pasurka; Theo Falck; Joshua Kubach; Stefan Söllner; Deike Strobel; Mario Perl; Marcel Betsch

doi:10.1016/j.jor.2025.08.027

View/Download PDF

Buy Reprints

PDF

Translate this page into:

70 (); 276-282

doi:

10.1016/j.jor.2025.08.027

Mapping tendon stiffness: Two-dimensional versus point shear wave elastography

Mario Pasurka^a,, Theo Falck^a, Joshua Kubach^a, Stefan Söllner^a, Deike Strobel^b, Mario Perl^a, Marcel Betsch^a

a Department of Orthopaedic and Trauma Surgery, University Hospital of Erlangen, Friedrich-Alexander-University Erlangen-Nuremberg, Krankenhaus 9, 91054, Erlangen, Germany

b Department of Medicine 1, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nuremberg, Ulmenweg 18, 91054, Erlangen, Germany

⁎Corresponding author: Mario Pasurka. mario.pasurka@gmx.de

Received: 2025-8-5, Accepted: 2025-8-16, Published: 2025-8-19

The Authors

Disclaimer:
This article was originally published by Reed Elsevier India Pvt. Ltd. and was migrated to Scientific Scholar after the change of Publisher.

Abstract

To date, no study has investigated the comparability between point shear wave elastography (pSWE) and 2D-shear wave elastography (2D-SWE) in assessing patellar tendon (PT) stiffness. In addition to comparing shear wave velocities, this study also evaluated intra- and interrater reliability, as well as measurement time.

Forty healthy subjects (20 females, 20 males; age: 23.3 ± 2.4 years, BMI: 22.46 ± 2.23 kg/m²) were recruited as participants. Each participant underwent a standardized multimodal ultrasound protocol that included B-mode ultrasound (B-US), Color Doppler ultrasound (CD-US), and a shear wave elastography (SWE) examination of the bilateral patellar tendon using both pSWE and 2D-SWE. Stiffness values and examination times were recorded. Intra- and interrater reliability were assessed across two different measurement time points with two investigators for both pSWE and 2D-SWE.

Elastography values were slightly higher for pSWE compared to 2D-SWE (pSWE: 4.02 ± 1.07 m/s, 2D-SWE: 3.82 ± 0.73 m/s; p < 0.001). 2D-SWE10 measurements took significantly more time than pSWE (2D-SWE10: 69.89 ± 13.46 s vs. pSWE: 54.85 ± 8.34 s, p < 0.001). However, the time required for 2D-SWE1 was significantly shorter than for pSWE (2D-SWE1: 47.20 ± 8.23 s vs. pSWE: 54.85 ± 8.34 s, p < 0.001). Both interrater and intrarater reliability reached excellent levels for all SWE measurements, with the highest interrater and intrarater ICC values obtained for 2D-SWE1.

This is the first study to evaluate and compare pSWE and 2D-SWE in the assessment of patellar tendon stiffness. These findings could have important implications for the clinical use of musculoskeletal SWE, providing insights into measurement time, reliability, and the potential benefits of using 2D-SWE in clinical practice.

Keywords

Tendon stiffness

Musculoskeletal ultrasound

Acoustic radiation force impulse imaging

Point shear-wave elastography

Two-dimensional shear wave elastography

Show Related Articles from PubMed

1 Introduction

Elastosonography, which includes both compression elastography and shear wave elastography (SWE), has emerged as a valuable modality for the evaluation of tissue stiffness. In particular, SWE has gained increasing prominence in musculoskeletal research over years.¹^,² Unlike compression elastography, SWE does not rely on examiner-applied pressure, which improves its reliability, objectivity and reproducibility.² Additionally, SWE enables quantitative assessment of tissue properties by measuring Young's modulus. (in kilopascals) or shear wave velocity (in meters per second), facilitating direct comparison between individual structures.

A recently published guideline on operational standards for musculoskeletal SWE from China recommends the use of shear wave velocity (unit: m/s) as the primary quantitative parameter.³ Originally introduced as transient elastography in 2003 for the quantitative assessment of liver stiffness,⁴ SWE has since evolved and found increasing application in the evaluation of ligaments, muscles and tendons, demonstrating good to excellent intra- and interrater reliability in these tissues.²^,⁵^,⁶ Alongside the progressive development of the technique, various SWE modalities have been emerged. Point shear wave elastography (pSWE), for instance, employs a small region of interest (ROI) of approximately 6 × 5 mm to record the shear wave velocity measurements. Two-dimensional shear wave elastography (2D-SWE) has been recently introduced as an advanced technique for tissue characterization. It generates a real-time color map of shear wave propagation, enabling recording of shear wave velocity with a sample box measuring 20 × 30 mm. A variably sized ROI can be positioned within this field to precisely localize the measurement.⁴ Recent studies have compared the performance of 2D-SWE compared and pSWE in the assessment of liver stiffness.⁷^,⁸ 2D-SWE demonstrated higher diagnostic accuracy for the detection of liver cirrhosis. Moreover, no significant difference in diagnostic value was observed between three and five measurements,⁸ although 2D-SWE was associated with a longer acquisition time compared to pSWE.⁷ Currently, little evidence is available comparing pSWE and 2D-SWE in the assessment of musculoskeletal tissue stiffness. A study by Yurdaisik investigated the diagnostic accuracy of pSWE and 2D-SWE techniques for patellar tendinopathy, using magnetic resonance imaging (MRI) as a reference, and reported a strong correlation between SWE and pSWE measurements.⁹ Despite the growing use of SWE for musculoskeletal applications, no consensus has been established regarding the optimal number of measurements required to obtain valid and reliable results. The aim of this study was to build on previously published literature and investigate the comparability between pSWE and 2D-SWE values (shear wave velocities in m/s) in assessing patellar tendon (PT) stiffness in healthy individuals. Additionally, the study compared examination time, as well as intrarater and interrater reliability, between both methods, and two different approaches of 2D-SWE were evaluated. We hypothesize that 2D-SWE is a reliable and valid method for assessing patellar tendon stiffness.

2 Materials and methods

2.1

2.1 Ethics approval

The local ethics committee approved the methods of the study (Ref. No. 24-236-B; University of XX, XX, XXXX). All participants were informed about the purpose, benefits and risks of the investigation prior to signing an institutionally approved informed consent to participate in the study according to the principles found in the Declaration of Helsinki.

2.2

2.2 Experimental approach

The present study was designed to investigate the comparability between pSWE and 2D-SWE values (shear wave velocities in m/s) in assessing patellar tendon (PT) stiffness. Each participant underwent multiple ultrasound investigations and a clinical assessment. All examinations were performed by two skilled investigators, each with over four and six years of experience in musculoskeletal ultrasound imaging and shear wave elastography. The main dependent outcome measures of the study included: 1) stiffness properties of PT, as measured by the tissue specific shear wave velocity (SWV) using pSWE and 2D-SWE; 2) modified Ohberg score¹⁰ measured with Color Doppler ultrasound (CD-US) to identify neovascularization; 3) clinical measures, including knee range of motion (ROM), Lysholm Score,^11–13 International Knee Documentation Committee (IKDC) Score¹⁴^,¹⁵ and 4) time required for measurements in pSWE and 2D-SWE. All measurements were performed under resting conditions in a supine position with the knee in full extension (0 degrees of flexion).

2.3

2.3 Study population

Forty healthy adults (n = 40 subjects, n = 80 knees) were recruited as participants from the medical faculty at the local university between July 2024 and September 2024. The inclusion criteria were: no clinical knee impairment, full knee ROM, and both objective and subjective knee stability. The exclusion criteria included signs, symptoms, and a history of acute or overuse injuries of the knee as well as tendons with recognized neovascularization on Color Doppler Ultrasound (CD-US). None of the participants has impairments in their daily or sporting activities, and therefore, all were considered healthy. All participants were advised to refrain from sport activities for 48 h prior to data collection.¹⁶

2.4

2.4 Clinical assessment

Clinical function was assessed using the Lysholm Score^11–13 and IKDC Score.¹⁴^,¹⁵ Passive and active range of motion (ROM) of the knee joint was measured using a handheld goniometer (Bauerfeind AG, Zeulenroda-Triebes, Germany), following the standard procedure described by Norkin and White (2009).¹⁷ The clincal scores were assessed prior to the ultrasound examination.

2.5

2.5 Ultrasound examination and data acquisition

Data were collected under standardized laboratory conditions, with the room temperature set at 21 °C. Participants were instructed to lie in in the supine position, placing the knee in a neutral position. The highest interobserver and intraobserver agreement for PT was previously shown for neutral position.¹⁸ For pSWE examinations, the Siemens S2000 ultrasound machine (Acuson S2000, Siemens Healthineers, Erlangen, Germany) was used. For 2D-SWE measurements, the APLIO™ i-series ultrasound system from Canon (Canon Medical Systems GmbH, Neuss, Germany) was used. First, conventional B- mode ultrasound was conducted using a linear probe with a frequency of 9 MHz for anatomical orientation, to rule out abnormalities, and to set the anatomical landmarks for measuring the mid portion regions, based on previously published protocols^19–22 (marking 1 cm distal to the caudal tip of the patella and 1 cm proximal to the tibial insertion). Then, a color-coded Doppler sonographic measurement of the respective tendon was carried out to determine the modified Ohberg score.

2.6

2.6 Tendon evaluation by B-US

Positive findings for abnormalities and tendinopathy included inhomogeneous tendon texture, hypoechogenic tendon swelling or thickening (compared to surrounding tendon areas), partial tear, tendon calcification, or fluid in the paratenon, as described previously.²³ Tendons without any these structural abnormalities and findings were considered “healthy” and were included in the study (Figs. 1 and 2).

B-US of healthy patellar tendon with the APLIO™ i-series ultrasound system from Canon (Canon Medical Systems GmbH, Neuss, Germany) P: patella, PT: patellar tendon, T: tibia.

B-US of healthy patellar tendon with the Siemens S2000 ultrasound machine (Acuson S2000, Siemens Healthineers, Erlangen, Germany) P: patella, PT: patellar tendon, T: tibia.

2.7

2.7 Tendon evaluation by Color Doppler Ultrasound (CD-US)

CD-US was used to detect hypervascularized areas in the patellar tendons by systematically scanning the tendons using CD-US. Any neovascularization, regardless of its intensity, was considered as positive finding.²⁴^,²⁵ Participants with neovascularization were excluded from the study. Tendons without recognizable neovascularization were considered “healthy”. The amount of neovascularization was graded using a modified Ohberg score (0 = no vessels; 1 = paratendinous vessels; 2 = 1 or 2 intratendinous vessels; 3 = 3 intratendinous vessels; 4 = >3 intra-tendinous vessels)²⁶ (Fig. 3). Intraclass correlation coefficients (ICC) for interrater reliability (0.86) and for intrarater reliability (0.95) have been reported previously.²⁷

Assessing neovascularization via CD-US (No vessels detected indicating a modified Ohberg score of 0 in a healthy patellar tendon).

2.8

2.8 Assessing tissue stiffness

SWE measurements were performed according to the latest published Guideline on Operational Standards for Shear Wave Elastography Examination of Musculoskeletal Tissues.³ Patients were simply randomized in terms of the order of examinations (pSWE first or 2D-SWE first). As recommended, absolute shear wave velocities (SWV; in m/s) were obtained from the representative ROI along the longitudinal parallel axis of the investigated structure to avoid any anisotropic effects.^28–30

2.8.1

2.8.1 pSWE

Tissue stiffness was evaluated using ARFI elastography, which has demonstrated high reliability and validity for musculoskeletal purposes.⁵^,³¹^,³² The ARFI settings were as follows: a fixed-size ARFI region of interest (ROI) of 6 mm × 5 mm, a frequency of 8 MHz and a mechanical index (MI) of 1.6. During the ARFI examination, B-mode ultrasound was used simultaneously for ROI positioning (Fig. 4). Ten measurement repetitions with 10 manually chosen ROI positions were performed, scanning the mid portion of the PT based on the fixed field of view, following previously published protocols.⁵^,²⁹^,³³

For 2D-SWE, a ROI was positioned according to the same criteria as for pSWE. If possible, the same location was chosen for positioning the ROI in both pSWE and 2D-SWE by scanning the mid portion of patellar tendon.

Measurements were considered valid if the sample box was homogeneously colored (Fig. 5). The continuous mode was used to find the optimal position of the ROI. Once the elastogram was stable for at least 3 s, the multi-mode was used for image acquisition. Using at least 10 data acquisition time points, 10 valid measurements were performed in each patient with a ROI of 3 mm in diameter (Fig. 6). Measurements were considered failures, and patients were excluded from the study if no stable elastogram could be obtained within 3 min. Additionally, 10 valid measurements using only one data acquisition time point were performed (Fig. 7).

Homogeneously colored sample box in the mid portion of patellar tendon (regions nearby the patella/bone exhibit higher SWE/different color).

Assessing tissue stiffness via 2D-SWE using a ROI of 3 mm in diameter (only one measurement per acquisition time point).

Assessing tissue stiffness via 2D-SWE (multiple measurements using only one data acquisition time point).

2.9

2.9 Reliability measurements

The interobserver reliability (repeated sessions) was determined for both knee joints of the study population (nsubjects = 40; nknees = 80) by two different observers. For each observer, a complete measurement session was performed including participant positioning, B-mode ultrasound for anatomical orientation, CD-ultrasound with determination of the modified Ohberg score and the SWE measurements using pSWE and 2D-SWE. The intraobserver reliability (repeated days) was performed for both knee joints of the study population (nsubjects = 20; nknees = 40) as well. A follow-up time of one day was chosen between the first (day1) and second (day 2) session.

2.10

2.10 Statistical analysis

Ultrasound images for all B-mode, SWE and CD-US measurements were digitized and exported as uncompressed TIFF files. Values are expressed as the mean and standard deviation (SD) of the mean. Differences within the group were assessed using the Wilcoxon–Mann–Whitney–U-test. P values of <0.05 were regarded as statistically significant. The analysis was carried out with the SPSS statistics program (IBM Deutschland GmbH, Ehningen, Deutschland) for Windows (Microsoft Corporation, Redmond, USA). Sample size calculation was performed using a power analysis with the program G∗Power (Heinrich-Heine-University Düsseldorf, Germany).³⁴ Based on previous studies,⁷^,⁸ a sample size of at least n = 20 per group was calculated to achieve a power >0.95.

3 Results

3.1

3.1 Patient characteristics, clinical examination and scores

Forty healthy subjects (20 females, 20 males, age: 23.3 ± 2.36 years, BMI: 22.46 ± 2.23 kg/m²) were included as participants. Patient characteristics are summarized in Table 1. All participants achieved full knee ROM (Extension/Flexion 0-0-140°), full Lysholm score (100 ± 0) and full IKDC Scores (100 ± 0). None of the participants showed any signs of neovascularization (Ohberg-Score: 0 ± 0).

Table 1 Baseline characteristics (Data are expressed as the mean ± SD).

Parameter	Values
Height (cm)	180.70 ± 10.85
Weight (kg)	74.95 ± 14.13
BMI (kg/m2)	22.46 ± 2.23
Age (years)	23.3 ± 2.36

3.2

3.2 Interrater and intrarater reliability

Interrater and Intrarater reliability reached excellent levels for all three SWE measurements. Highest Interrater and Intrarater ICC values were obtained for 2D-SWE1 (Table II).

3.3

3.3 Results from pSWE and 2D-SWE measurements

Table III shows the results from pSWE and 2D-SWE-measurements (mean values from 80 individual measurements from both observers). Elastography values were slightly higher for pSWE than for 2D-SWE (pSWE: 4.02 ± 1.07 m/s, 2D-SWE: 3.82 ± 0.73 m/s). These differences were statistically significant (p < 0.001).

3.4

3.4 Time required for measurements in pSWE and 2D-SWE

As one parameter of usefulness in clinical routine, we compared the time required for measurements in pSWE and 2D-SWE (Table 2). As the gold standard, we defined 10 measurements in pSWE as shown previously.³⁵ For 2D-SWE, we also considered 10 measurements as the gold standard. Two series of 2D-SWE measurements were carried out. First, only one measurement per acquisition time point was performed in at least 10 acquisition time points (2D-SWE10). Second, 10 measurements using only one data acquisition time point were carried out (2D-SWE1). 2D-SWE10 measurements required significant more time compared to pSWE (2D-SWE10 vs. pSWE: 69.89 ± 13.46 s vs. 54.85 ± 8.34 s, p < 0.001). Time required for 2D-SWE1 was statistically significant lower compared to pSWE (2D-SWE1 vs. pSWE: 47.20 ± 8.23 s vs. 54.85 ± 8.34 s, p < 0.001).

Table 2 Interrater and Intrarater reliability of SWE measurements (CI: Confidence interval).

	pSWE	2D-SWE10	2D-SWE1
Interrater ICC (95 % CI)	0.896 (0.804–0.945)	0.925 (0.859–0.961)	0.979 (0.946–0.992)
Intrarater ICC (95 % CI)	0.979 (0.947–0.992)	0.960 (0.872–0.980)	0.992 (0.984–0.996)

Table 3 Comparison of SWV values and time from pSWE and 2D-SWE measurements (2D-SWE10: 10 acquisitions, 2D-SWE1: one acquisition, data are expressed as mean ± SD).

Value	pSWE	2D-SWE10	2D-SWE1	p(pSWE vs. 2D-SWE10)	p(pSWE vs. 2D-SWE1)	p(2DSWE¹ vs. 2D-SWE10)
SWV (m/s)	4.02 ± 1.07	3.82 ± 0.73	3.75 ± 0.77	<0.001	<0.001	0.475
Time (seconds)	54.85 ± 8.34	69.89 ± 13.46	47.20 ± 8.23	<0.001	<0.001	<0.001

4 Discussion

SWE has increasingly gained scientific attention in the assessment of musculoskeletal tissue stiffness due to its non-invasive nature, high reproducibility, and ability to provide realt-time, quantitative measurements of tissue elasticity. However, 2D-SWE has not been sufficiently validated for musculoskeletal tissues. Therefore, the aim of the present study was to compare 2D-SWE with the most frequently used technique, pSWE, in musculoskeletal imaging, using the patellar tendon as an example.

The results of the present study showed that 2D-SWE is a reliable and valid alternative for assessing patellar tendon stiffness. With 2D-SWE, the size of the ROI for elastography measurements can be adjusted, offering flexibility in measurement areas. Additionally, visual feedback is provided during the measurement process to confirm its validity, which enhances the accuracy of the results. The excellent reliability scores further support the method's consistency. These findings are adavantageous because they suggest that 2D-SWE can provide accurate and adaptable measurements, making it a promising tool for clinical practice, where real-time feedback and customizable measurement areas are essential for precise evaluations of tissue stiffness.

Assuming one acquisition time point is sufficient, the time required for valid measurements is statistically significant shorter when assessing PT stiffness with 2D-SWE. SWV values measured with 2D-SWE were significantly lower than those obtained with pSWE. A possible reason for this difference could be the visual feedback provided by 2D-SWE. To achieve homogeneous color coding, the examiner is required to apply a minimum amount of pressure on the tissue. In contrast, since no visual feedback is given during pSWE, it can be assumed that the pressure applied to the tissue is higher leading to tissue compression, which may increase the SWV values.

There is still no consensus regarding the number of measurements in musculoskeletal SWE. A 2024 guideline on Operational Standards for 2-D Shear Wave Elastography Examination of Musculoskeletal Tissues developed evidence-based recommendations for 2-D shear wave elastography procedures.³ However, there is no consensus or specific guideline on the number of measurements, particularly for 2D-SWE. While 10 measurements were defined as the gold standard in pSWE assessment of liver stiffness,³⁵ most studies investigating musculoskeletal pSWE have also used this number.

A study from Schellhaas et al.⁷ assumed seven measurements as the gold standard for 2D-SWE in the assessment of liver stiffness, as this number lies in between the gold standard of five measurements accepted for Supersonic Imagine⁸^,³⁶ and the 10 measurements accepted for ARFI.⁴ With color coded mapping visual feedback is provided, allowing the examiner to ensure valid values in the measured area. This raises the question of whether multiple acquisitions are necessary in 2D-SWE for musculoskeletal tissue. In our study, we scanned the mid portion of the patellar tendon in a fixed area and performed two different approaches for 2D-SWE measurements. First, 10 valid measurements were performed for each patient using 10 data acquisition time points. Second, 10 valid measurements were performed for each patient using only one data acquisition time point. There was a minimal difference between SWV values and SD, when comparing both approaches, suggesting that a single acquisition may be sufficient. However, particular attention must be paid to achieving a homogeneously colored sample box. In addition, to ensure the validity of ongoing measurement, color coded mapping can provide additional certainty in clinical practice, especially for untrained examiners.

To assess the usefulness of 2D-SWE as an alternative to pSWE in clinical practice, we compared the time required to complete valid measurements for both methods. Ten measurements with ten acquisition time points in 2D-SWE took significantly more time than 10 single measurements in pSWE. However, assuming that 10 measurements from a single high-quality acquisition in 2D-SWE may be sufficient to obtain valid results for healthy patellar tendons, 2D-SWE could provide faster results for assessing PT stiffness.

In our study, we also investigated the intra- and interrater reliability of pSWE and 2D-SWE.

Consistent with our results, several studies investigating the intra- and interrater reliability in the assessment of musculoskeletal tissues have reported good to excellent results.²^,⁵^,⁶^,³⁷ In the present study, the highest ICC values were found for 2D-SWE with one acquisition time point, followed by 2D-SWE with multiple acquisition time points and pSWE measurements. However, all values reached excellent level, except for pSWE interrater reliability, which showed good to almost excellent results.³⁸

Despite the increasing scientific attention of SWE in the assessment of musculoskeletal tissue, there is still a lack of standardization. Variations in measurement protocols, tendon sections and joint angles lead to a wide range of normative values for the same anatomical structures. Additionally, there are patient-related factors that cannot be controlled.

Besides age,²¹ gender,¹⁹^,²²^,³⁹^,⁴⁰ and body mass index,⁴¹ physical activity level¹⁹^,⁴⁰^,^42–44 especially seem to influence SWE measurements. However, there are also examiner-dependent factors, such as joint angle,³⁹^,^45–47 muscle force⁴⁷ and exercise prior to measurement,¹⁶ that affect tendon properties. Comparing different knee joint positions, a recent study by Pelea et al. found the highest overall interobserver and intraobserver when the knee was in the neutral position, compared to 30-degree and 45-degree knee flexion, in the assessment of PT using 2D-SWE.¹⁸ This suggests that 2D-SWE assessment of PT should be conducted in the neutral position to obtain the most reproducible values. In clinical practice, bending the knee may offer better visualization of PT. However, the feasibility of imaging the PT in the neutral position is also good due to its superficial location.

This study highlights the promising benefits of 2D-SWE for assessing musculoskeletal tissue and provides initial insights into the required number of measurements for its implementation of 2D-SWE in clinical practice. Further studies are needed to investigate musculoskeletal 2D-SWE in order to establish recommendations on the number of f measurements required for valid results in in the operational standards for 2D-SWE examination of musculoskeletal tissues.

This study has several limitations that need to be addressed. First, the patellar tendon was evaluated, and it remains unclear whether the results can be generalized to other musculoskeletal tissues. Further studies are needed to gain more insights in these areas. All examinations were performed by two skilled investigators, with over four and six years of experience in musculoskeletal ultrasound imaging and shear wave elastography. However, the two investigators primarily used pSWE and not 2D-SWE in recent years. Despite a steep learning curve with 2D-SWE, the potential influence of this factor on the results cannot be ruled out. Additionally, only participants with healthy PT were included, and the entire mid portion of the PT was scanned using varying ROI positions. In cases of tendon pathology, such as tendinopathy, differing results may be observed.

5 Conclusion

2D-SWE proves to be a highly effective and reliable alternative to pSWE for assessing patellar tendon stiffness. With its real-time feedback ensuring measurement validity, excellent reliability scores, and the added benefit of time efficiency, 2D-SWE has the potential to improve clinical practice. These findings highlight the promising future of 2D-SWE as a tool that not only delivers accurate results but also enhances workflow in musculoskeletal assessments.

Statement identifying the authors contributions to the manuscript

All authors must have made substantial contributions.

Mario Pasurka: Conceptualization; Data curation; Investigation; Methodology; Project administration; Resources; Supervision; Validation; Visualization; Roles/Writing - original draft; Writing - review & editing.

Theo Falck: Conceptualization; Data curation; Investigation; Methodology; Resources; Visualization; Roles/Writing - original draft; and Writing - review & editing.

Joshua Kubach: Resources; Software; Supervision; Validation; Visualization; Writing - review & editing.

Stefan Söllner: Methodology; Resources; Software; Supervision; Validation; Writing - review & editing.

Deike Strobel: Conceptualization; Data curation; Formal analysis; Supervision; Validation; Writing - review & editing.

Mario Perl: Data curation; Formal analysis; Supervision; Validation; Writing - review & editing.

Marcel Betsch: Data curation; Formal analysis; Supervision; Validation; Writing - review & editing.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

References

Horvat U., Kozinc Ž., . The use of shear-wave ultrasound elastography in the diagnosis and monitoring of musculoskeletal injuries. Crit Rev Biomed Eng. 2024;52(2):15-26.
[Google Scholar]
Prado-Costa R., Rebelo J., Monteiro-Barroso J., Preto A.S., . Ultrasound elastography: compression elastography and shear-wave elastography in the assessment of tendon injury. Insights Imaging. Oct 2018;9(5):791-814.
[Google Scholar]
Zhu J., Qiu L., Ta D., et al . Chinese ultrasound doctors association guideline on operational standards for 2-D shear wave elastography examination of musculoskeletal tissues. Ultrasound Med Biol. Feb 2024;50(2):175-183.
[Google Scholar]
Piscaglia F., Salvatore V., Mulazzani L., Cantisani V., Schiavone C., . Ultrasound shear wave elastography for liver disease. A critical appraisal of the many actors on the stage. Ultraschall Med. Feb 2016;37(1):1-5.
[Google Scholar]
Hotfiel T., Heiss R., Janka R., et al . Acoustic radiation force impulse tissue characterization of the anterior talofibular ligament: a promising noninvasive approach in ankle imaging. Phys Sportsmed. Nov 2018;46(4):435-440.
[Google Scholar]
Porta F., Damjanov N., Galluccio F., Iagnocco A., Matucci-Cerinic M., . Ultrasound elastography is a reproducible and feasible tool for the evaluation of the patellar tendon in healthy subjects. Int J Rheum Dis. Sep 2014;17(7):762-766.
[Google Scholar]
Schellhaas B., Strobel D., Wildner D., Goertz R.S., Neurath M.F., Pfeifer L., . Two-dimensional shear-wave elastography: a new method comparable to acoustic radiation force impulse imaging? Eur J Gastroenterol Hepatol. Jun 2017;29(6):723-729.
[Google Scholar]
Thiele M., Madsen B.S., Procopet B., et al . Reliability criteria for liver stiffness measurements with real-time 2D shear wave elastography in different clinical scenarios of chronic liver disease. Ultraschall Med Reliabilitätskriterien für die Messung der Lebersteifigkeit mittels Echtzeit-2D-Shearwave-Elastografie bei verschiedenen klinischen Szenarien der chronischen Lebererkrankung. Dec 2017;38(6):648-654.
[Google Scholar]
Yurdaışık I., . Comparison of two-dimensional shear wave elastography and point shear wave elastography techniques with magnetic resonance findings in detection of patellar tendinopathy. Eklem Hastalik Cerrahisi. Dec 2019;30(3):275-281.
[Google Scholar]
Risch L., Wochatz M., Messerschmidt J., Engel T., Mayer F., Cassel M., . Reliability of evaluating achilles tendon vascularization assessed with Doppler ultrasound advanced dynamic flow. J Ultrasound Med. Mar 2018;37(3):737-744.
[Google Scholar]
Briggs K.K., Lysholm J., Tegner Y., Rodkey W.G., Kocher M.S., Steadman J.R., . The reliability, validity, and responsiveness of the Lysholm score and Tegner activity scale for anterior cruciate ligament injuries of the knee: 25 years later. Am J Sports Med. May 2009;37(5):890-897.
[Google Scholar]
Chamorro-Moriana G., Perez-Cabezas V., Espuny-Ruiz F., Torres-Enamorado D., Ridao-Fernandez C., . Assessing knee functionality: systematic review of validated outcome measures. Ann Phys Rehabil Med. Nov 2022;65(6)
[Google Scholar]
Tegner Y., Lysholm J., . Rating systems in the evaluation of knee ligament injuries. Clin Orthop Relat Res. Sep 1985;198:43-49.
[Google Scholar]
Grevnerts H.T., Terwee C.B., Kvist J., . The measurement properties of the IKDC-subjective knee form. Knee Surg Sports Traumatol Arthrosc. Dec 2015;23(12):3698-3706.
[Google Scholar]
Higgins L.D., Taylor M.K., Park D., et al . Reliability and validity of the international knee documentation committee (IKDC) subjective knee form. Jt Bone Spine. Dec 2007;74(6):594-599.
[Google Scholar]
Heales L.J., Badya R., Ziegenfuss B., et al . Shear-wave velocity of the patellar tendon and quadriceps muscle is increased immediately after maximal eccentric exercise. Eur J Appl Physiol. Aug 2018;118(8):1715-1724.
[Google Scholar]
Norkin C.C., White D.J., . Measurement of Joint Motion; a Guide to Goniometry. 2009
[Google Scholar]
Pelea M.A., Serban O., Badarinza M., Rosca R., Fodor D., . Factors influencing the Shear Wave Elastography evaluation of the patellar tendon. Med Ultrason. Jun 26 2023;25(2):145-152.
[Google Scholar]
Gotschi T., Hanimann J., Schulz N., et al . Patellar tendon shear wave velocity is higher and has different regional patterns in elite competitive alpine skiers than in healthy controls. Front Bioeng Biotechnol. 2022;10
[Google Scholar]
Götschi T., Schulz N., Snedeker J.G., Hanimann J., Franchi M.V., Spörri J., . Three-dimensional mapping of shear wave velocity in human tendon: a proof of concept study. Sensors (Basel). Feb 27 2021;21(5)
[Google Scholar]
Hsiao M.Y., Chen Y.C., Lin C.Y., Chen W.S., Wang T.G., . Reduced patellar tendon elasticity with aging: in vivo assessment by shear wave elastography. Ultrasound Med Biol. Nov 2015;41(11):2899-2905.
[Google Scholar]
Itoigawa Y., Takazawa Y., Maruyama Y., et al . A new technique of surgical planning for anterior cruciate ligament reconstruction: feasibility Assessment of Shear Wave Elastography to Tendon of Semitendinosus Muscle. Clin Anat. Apr 2018;31(3):404-408.
[Google Scholar]
Dong Q., Fessell D.P., . Achilles tendon ultrasound technique. AJR Am J Roentgenol. Sep 2009;193(3)
[Google Scholar]
Maffulli N., Sharma P., Luscombe K.L., . Achilles tendinopathy: aetiology and management. J R Soc Med. Oct 2004;97(10):472-476.
[Google Scholar]
Ohberg L., Alfredson H., . Ultrasound guided sclerosis of neovessels in painful chronic Achilles tendinosis: pilot study of a new treatment. Br J Sports Med. Jun 2002;36(3):173-175.
[Google Scholar]
de Vos R.J., Weir A., Cobben L.P., Tol J.L., . The value of power Doppler ultrasonography in Achilles tendinopathy: a prospective study. Am J Sports Med. Oct 2007;35(10):1696-1701.
[Google Scholar]
Watson J., Barker-Davies R.M., Bennett A.N., et al . Sport and exercise medicine consultants are reliable in assessing tendon neovascularity using ultrasound Doppler. BMJ Open Sport Exerc Med. 2018;4(1)
[Google Scholar]
Bruno C., Minniti S., Bucci A., Pozzi Mucelli R., . ARFI: from basic principles to clinical applications in diffuse chronic disease-a review. Insights Imaging. Oct 2016;7(5):735-746.
[Google Scholar]
Heiss R., Kellermann M., Swoboda B., et al . Effect of compression garments on the development of delayed-onset muscle soreness: a multimodal approach using contrast-enhanced ultrasound and acoustic radiation force impulse elastography. J Orthop Sports Phys Ther. Nov 2018;48(11):887-894.
[Google Scholar]
Yavuz A., Bora A., Bulut M.D., et al . Acoustic Radiation Force Impulse (ARFI) elastography quantification of muscle stiffness over a course of gradual isometric contractions: a preliminary study. Med Ultrason. Mar 2015;17(1):49-57.
[Google Scholar]
Peltz C.D., Haladik J.A., Divine G., Siegal D., van Holsbeeck M., Bey M.J., . ShearWave elastography: repeatability for measurement of tendon stiffness. Skelet Radiol. Aug 2013;42(8):1151-1156.
[Google Scholar]
Zardi E.M., Franceschetti E., Giorgi C., Palumbo A., Franceschi F., . Reliability of quantitative point shear-wave ultrasound elastography on vastus medialis muscle and quadriceps and patellar tendons. Med Ultrason. Feb 17 2019;21(1):50-55.
[Google Scholar]
Hotfiel T., Kellermann M., Swoboda B., et al . Application of acoustic radiation force impulse elastography in imaging of delayed onset muscle soreness: a comparative analysis with 3T MRI. J Sport Rehabil. Jul 1 2018;27(4):348-356.
[Google Scholar]
Faul F., Erdfelder E., Lang A.-G., Buchner A., . G∗Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007;39:175-191.
[Google Scholar]
Ferraioli G., Filice C., Castera L., et al . WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 3: liver. Ultrasound Med Biol. May 2015;41(5):1161-1179.
[Google Scholar]
Sporea I., Bota S., Jurchis A., et al . Acoustic radiation force impulse and supersonic shear imaging versus transient elastography for liver fibrosis assessment. Ultrasound Med Biol. Nov 2013;39(11):1933-1941.
[Google Scholar]
Taş S., Onur M.R., Yılmaz S., Soylu A.R., Korkusuz F., . Shear wave elastography is a reliable and repeatable method for measuring the elastic modulus of the rectus femoris muscle and patellar tendon. J Ultrasound Med. Mar 2017;36(3):565-570.
[Google Scholar]
Koo T.K., Li M.Y., . A guideline of selecting and reporting intraclass correlation coefficients for reliability research. J Chiropr Med. Jun 2016;15(2):155-163.
[Google Scholar]
Ebihara B., Mutsuzaki H., Fukaya T., . Relationships between quadriceps tendon elasticity and knee flexion angle in Young healthy adults. Medicina (Kaunas). Feb 15 2019;55(2)
[Google Scholar]
Magnusson S.P., Hansen M., Langberg H., et al . The adaptability of tendon to loading differs in men and women. Int J Exp Pathol. Aug 2007;88(4):237-240.
[Google Scholar]
Gumina S., Candela V., Passaretti D., et al . The association between body fat and rotator cuff tear: the influence on rotator cuff tear sizes. J Shoulder Elb Surg. Nov 2014;23(11):1669-1674.
[Google Scholar]
Cristi-Sanchez I., Danes-Daetz C., Neira A., Ferrada W., Yanez Diaz R., Silvestre Aguirre R., . Patellar and achilles tendon stiffness in elite soccer players assessed using myotonometric measurements. Sports Health. Mar/Apr 2019;11(2):157-162.
[Google Scholar]
Pasurka M., Falck T., Kubach J., et al . Comparison of in vivo stiffness of tendons commonly used for anterior cruciate ligament reconstruction - a shear wave elastography study. Acad Radiol. Aug 2024;31(8):3297-3305.
[Google Scholar]
Selcuk Can T., Ozdemir S., Yilmaz B.K., . Shear-wave elastography of patellar ligament and achilles tendon in semiprofessional athletes: comparing with nonexercising individuals. J Ultrasound Med. Sep 2022;41(9):2237-2246.
[Google Scholar]
Coombes B.K., Ziegenfuss B., David M., et al . Heterogeneity of passive elastic properties within the quadriceps femoris muscle-tendon unit. Eur J Appl Physiol. Jan 2018;118(1):213-221.
[Google Scholar]
Fontenelle C.R.C., Mannarino P., Ribeiro F., et al . Semitendinosus and patellar tendons shear modulus evaluation by supersonic shearwave imaging elastography. Clin Physiol Funct Imaging Feb 7 2018
[Google Scholar]
Kuervers E.J., Firminger C.R., Edwards W.B., . Effect of knee angle and quadriceps muscle force on shear-wave elastography measurements at the patellar tendon. Ultrasound Med Biol. Aug 2021;47(8):2167-2175.
[Google Scholar]

Show Sections

[1] Horvat U., Kozinc Ž., . The use of shear-wave ultrasound elastography in the diagnosis and monitoring of musculoskeletal injuries. Crit Rev Biomed Eng. 2024;52(2):15-26.
[Google Scholar]

[2] Prado-Costa R., Rebelo J., Monteiro-Barroso J., Preto A.S., . Ultrasound elastography: compression elastography and shear-wave elastography in the assessment of tendon injury. Insights Imaging. Oct 2018;9(5):791-814.
[Google Scholar]

[3] Zhu J., Qiu L., Ta D., et al . Chinese ultrasound doctors association guideline on operational standards for 2-D shear wave elastography examination of musculoskeletal tissues. Ultrasound Med Biol. Feb 2024;50(2):175-183.
[Google Scholar]

[4] Piscaglia F., Salvatore V., Mulazzani L., Cantisani V., Schiavone C., . Ultrasound shear wave elastography for liver disease. A critical appraisal of the many actors on the stage. Ultraschall Med. Feb 2016;37(1):1-5.
[Google Scholar]

[5] Hotfiel T., Heiss R., Janka R., et al . Acoustic radiation force impulse tissue characterization of the anterior talofibular ligament: a promising noninvasive approach in ankle imaging. Phys Sportsmed. Nov 2018;46(4):435-440.
[Google Scholar]

[6] Porta F., Damjanov N., Galluccio F., Iagnocco A., Matucci-Cerinic M., . Ultrasound elastography is a reproducible and feasible tool for the evaluation of the patellar tendon in healthy subjects. Int J Rheum Dis. Sep 2014;17(7):762-766.
[Google Scholar]

[7] Schellhaas B., Strobel D., Wildner D., Goertz R.S., Neurath M.F., Pfeifer L., . Two-dimensional shear-wave elastography: a new method comparable to acoustic radiation force impulse imaging? Eur J Gastroenterol Hepatol. Jun 2017;29(6):723-729.
[Google Scholar]

[8] Thiele M., Madsen B.S., Procopet B., et al . Reliability criteria for liver stiffness measurements with real-time 2D shear wave elastography in different clinical scenarios of chronic liver disease. Ultraschall Med Reliabilitätskriterien für die Messung der Lebersteifigkeit mittels Echtzeit-2D-Shearwave-Elastografie bei verschiedenen klinischen Szenarien der chronischen Lebererkrankung. Dec 2017;38(6):648-654.
[Google Scholar]

[9] Yurdaışık I., . Comparison of two-dimensional shear wave elastography and point shear wave elastography techniques with magnetic resonance findings in detection of patellar tendinopathy. Eklem Hastalik Cerrahisi. Dec 2019;30(3):275-281.
[Google Scholar]

[10] Risch L., Wochatz M., Messerschmidt J., Engel T., Mayer F., Cassel M., . Reliability of evaluating achilles tendon vascularization assessed with Doppler ultrasound advanced dynamic flow. J Ultrasound Med. Mar 2018;37(3):737-744.
[Google Scholar]

[11] Briggs K.K., Lysholm J., Tegner Y., Rodkey W.G., Kocher M.S., Steadman J.R., . The reliability, validity, and responsiveness of the Lysholm score and Tegner activity scale for anterior cruciate ligament injuries of the knee: 25 years later. Am J Sports Med. May 2009;37(5):890-897.
[Google Scholar]

[12] Chamorro-Moriana G., Perez-Cabezas V., Espuny-Ruiz F., Torres-Enamorado D., Ridao-Fernandez C., . Assessing knee functionality: systematic review of validated outcome measures. Ann Phys Rehabil Med. Nov 2022;65(6)
[Google Scholar]

[13] Tegner Y., Lysholm J., . Rating systems in the evaluation of knee ligament injuries. Clin Orthop Relat Res. Sep 1985;198:43-49.
[Google Scholar]

[14] Grevnerts H.T., Terwee C.B., Kvist J., . The measurement properties of the IKDC-subjective knee form. Knee Surg Sports Traumatol Arthrosc. Dec 2015;23(12):3698-3706.
[Google Scholar]

[15] Higgins L.D., Taylor M.K., Park D., et al . Reliability and validity of the international knee documentation committee (IKDC) subjective knee form. Jt Bone Spine. Dec 2007;74(6):594-599.
[Google Scholar]

[16] Heales L.J., Badya R., Ziegenfuss B., et al . Shear-wave velocity of the patellar tendon and quadriceps muscle is increased immediately after maximal eccentric exercise. Eur J Appl Physiol. Aug 2018;118(8):1715-1724.
[Google Scholar]

[17] Norkin C.C., White D.J., . Measurement of Joint Motion; a Guide to Goniometry. 2009
[Google Scholar]

[18] Pelea M.A., Serban O., Badarinza M., Rosca R., Fodor D., . Factors influencing the Shear Wave Elastography evaluation of the patellar tendon. Med Ultrason. Jun 26 2023;25(2):145-152.
[Google Scholar]

[19] Gotschi T., Hanimann J., Schulz N., et al . Patellar tendon shear wave velocity is higher and has different regional patterns in elite competitive alpine skiers than in healthy controls. Front Bioeng Biotechnol. 2022;10
[Google Scholar]

[20] Götschi T., Schulz N., Snedeker J.G., Hanimann J., Franchi M.V., Spörri J., . Three-dimensional mapping of shear wave velocity in human tendon: a proof of concept study. Sensors (Basel). Feb 27 2021;21(5)
[Google Scholar]

[21] Hsiao M.Y., Chen Y.C., Lin C.Y., Chen W.S., Wang T.G., . Reduced patellar tendon elasticity with aging: in vivo assessment by shear wave elastography. Ultrasound Med Biol. Nov 2015;41(11):2899-2905.
[Google Scholar]

[22] Itoigawa Y., Takazawa Y., Maruyama Y., et al . A new technique of surgical planning for anterior cruciate ligament reconstruction: feasibility Assessment of Shear Wave Elastography to Tendon of Semitendinosus Muscle. Clin Anat. Apr 2018;31(3):404-408.
[Google Scholar]

[23] Dong Q., Fessell D.P., . Achilles tendon ultrasound technique. AJR Am J Roentgenol. Sep 2009;193(3)
[Google Scholar]

[24] Maffulli N., Sharma P., Luscombe K.L., . Achilles tendinopathy: aetiology and management. J R Soc Med. Oct 2004;97(10):472-476.
[Google Scholar]

[25] Ohberg L., Alfredson H., . Ultrasound guided sclerosis of neovessels in painful chronic Achilles tendinosis: pilot study of a new treatment. Br J Sports Med. Jun 2002;36(3):173-175.
[Google Scholar]

[26] de Vos R.J., Weir A., Cobben L.P., Tol J.L., . The value of power Doppler ultrasonography in Achilles tendinopathy: a prospective study. Am J Sports Med. Oct 2007;35(10):1696-1701.
[Google Scholar]

[27] Watson J., Barker-Davies R.M., Bennett A.N., et al . Sport and exercise medicine consultants are reliable in assessing tendon neovascularity using ultrasound Doppler. BMJ Open Sport Exerc Med. 2018;4(1)
[Google Scholar]

[28] Bruno C., Minniti S., Bucci A., Pozzi Mucelli R., . ARFI: from basic principles to clinical applications in diffuse chronic disease-a review. Insights Imaging. Oct 2016;7(5):735-746.
[Google Scholar]

[29] Heiss R., Kellermann M., Swoboda B., et al . Effect of compression garments on the development of delayed-onset muscle soreness: a multimodal approach using contrast-enhanced ultrasound and acoustic radiation force impulse elastography. J Orthop Sports Phys Ther. Nov 2018;48(11):887-894.
[Google Scholar]

[30] Yavuz A., Bora A., Bulut M.D., et al . Acoustic Radiation Force Impulse (ARFI) elastography quantification of muscle stiffness over a course of gradual isometric contractions: a preliminary study. Med Ultrason. Mar 2015;17(1):49-57.
[Google Scholar]

[31] Peltz C.D., Haladik J.A., Divine G., Siegal D., van Holsbeeck M., Bey M.J., . ShearWave elastography: repeatability for measurement of tendon stiffness. Skelet Radiol. Aug 2013;42(8):1151-1156.
[Google Scholar]

[32] Zardi E.M., Franceschetti E., Giorgi C., Palumbo A., Franceschi F., . Reliability of quantitative point shear-wave ultrasound elastography on vastus medialis muscle and quadriceps and patellar tendons. Med Ultrason. Feb 17 2019;21(1):50-55.
[Google Scholar]

[33] Hotfiel T., Kellermann M., Swoboda B., et al . Application of acoustic radiation force impulse elastography in imaging of delayed onset muscle soreness: a comparative analysis with 3T MRI. J Sport Rehabil. Jul 1 2018;27(4):348-356.
[Google Scholar]

[34] Faul F., Erdfelder E., Lang A.-G., Buchner A., . G∗Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007;39:175-191.
[Google Scholar]

[35] Ferraioli G., Filice C., Castera L., et al . WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 3: liver. Ultrasound Med Biol. May 2015;41(5):1161-1179.
[Google Scholar]

[36] Sporea I., Bota S., Jurchis A., et al . Acoustic radiation force impulse and supersonic shear imaging versus transient elastography for liver fibrosis assessment. Ultrasound Med Biol. Nov 2013;39(11):1933-1941.
[Google Scholar]

[37] Taş S., Onur M.R., Yılmaz S., Soylu A.R., Korkusuz F., . Shear wave elastography is a reliable and repeatable method for measuring the elastic modulus of the rectus femoris muscle and patellar tendon. J Ultrasound Med. Mar 2017;36(3):565-570.
[Google Scholar]

[38] Koo T.K., Li M.Y., . A guideline of selecting and reporting intraclass correlation coefficients for reliability research. J Chiropr Med. Jun 2016;15(2):155-163.
[Google Scholar]

[39] Ebihara B., Mutsuzaki H., Fukaya T., . Relationships between quadriceps tendon elasticity and knee flexion angle in Young healthy adults. Medicina (Kaunas). Feb 15 2019;55(2)
[Google Scholar]

[40] Magnusson S.P., Hansen M., Langberg H., et al . The adaptability of tendon to loading differs in men and women. Int J Exp Pathol. Aug 2007;88(4):237-240.
[Google Scholar]

[41] Gumina S., Candela V., Passaretti D., et al . The association between body fat and rotator cuff tear: the influence on rotator cuff tear sizes. J Shoulder Elb Surg. Nov 2014;23(11):1669-1674.
[Google Scholar]

[42] Cristi-Sanchez I., Danes-Daetz C., Neira A., Ferrada W., Yanez Diaz R., Silvestre Aguirre R., . Patellar and achilles tendon stiffness in elite soccer players assessed using myotonometric measurements. Sports Health. Mar/Apr 2019;11(2):157-162.
[Google Scholar]

[43] Pasurka M., Falck T., Kubach J., et al . Comparison of in vivo stiffness of tendons commonly used for anterior cruciate ligament reconstruction - a shear wave elastography study. Acad Radiol. Aug 2024;31(8):3297-3305.
[Google Scholar]

[44] Selcuk Can T., Ozdemir S., Yilmaz B.K., . Shear-wave elastography of patellar ligament and achilles tendon in semiprofessional athletes: comparing with nonexercising individuals. J Ultrasound Med. Sep 2022;41(9):2237-2246.
[Google Scholar]

[45] Coombes B.K., Ziegenfuss B., David M., et al . Heterogeneity of passive elastic properties within the quadriceps femoris muscle-tendon unit. Eur J Appl Physiol. Jan 2018;118(1):213-221.
[Google Scholar]

[46] Fontenelle C.R.C., Mannarino P., Ribeiro F., et al . Semitendinosus and patellar tendons shear modulus evaluation by supersonic shearwave imaging elastography. Clin Physiol Funct Imaging Feb 7 2018
[Google Scholar]

[47] Kuervers E.J., Firminger C.R., Edwards W.B., . Effect of knee angle and quadriceps muscle force on shear-wave elastography measurements at the patellar tendon. Ultrasound Med Biol. Aug 2021;47(8):2167-2175.
[Google Scholar]

Mapping tendon stiffness: Two-dimensional versus point shear wave elastography

Abstract