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Anterior Cruciate Ligament RuptureSWE-ACLNCT07555782

Shear-Wave Elastography of Regenerated Hamstring Tendons After ACL Reconstruction (SWE-ACL)

An observational study of Anterior Cruciate Ligament Rupture and Tendon Injuries, run by Fatih Sultan Mehmet Training and Research Hospital at 1 site in Turkey (Türkiye).

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Anterior cruciate ligament (ACL) reconstruction using autologous hamstring tendon grafts is a commonly performed procedure. Although the semitendinosus and gracilis tendons demonstrate regeneration at the donor site, the structural and biomechanical properties of the regenerated tissue may differ from native tendon… Read more about this study

Who is it for?
Ages 18 to 50 years
What is being tested?
Shear-Wave Elastography Assessment
How many people
29 participants
Where
1 siteTurkey (Türkiye)
Study dates
30 Mar 2025to 30 Apr 2026
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 50 years
  • All sexes
  • Adult

Study population: The study population will consist of adult patients who have undergone anterior cruciate ligament (ACL) reconstruction using autologous hamstring tendon grafts (semitendinosus and gracilis) and have completed at least 6 months of postoperative follow-up. Participants will be selected from a single tertiary referral center and will have available postoperative magnetic resonance imaging (MRI) and isokinetic muscle strength (Cybex) data. All eligible patients will undergo shear-wave elastography (SWE) assessment of the regenerated hamstring tendons at the time of study enrollment.

Who may be able to join

  • Patients who have undergone anterior cruciate ligament (ACL) reconstruction using autologous hamstring tendon grafts (semitendinosus and gracilis)
  • At least 6 months of postoperative follow-up
  • Availability of postoperative magnetic resonance imaging (MRI) and isokinetic muscle strength (Cybex) measurements
  • Willingness to participate and provide informed consent

Who cannot join

  • History of previous surgery on the same lower extremity (other than the index ACL reconstruction)
  • Presence of neuromuscular disorders affecting lower extremity function
  • Incomplete clinical, imaging, or functional data
  • Inability to undergo elastography assessment

Trial locations and contacts

1 site in 1 country.

Turkey (Türkiye)1 site
  • Fatih Sultan Mehmet Training and Research Hospital

    Ataşehir, Istanbul, 34752

Other trials in Turkey (Türkiye)

About this study

Official title: Quantitative Assessment of Regenerated Hamstring Tendon Elasticity Using Shear-Wave Elastography and Its Relationship With Isokinetic Muscle Strength and Clinical Outcomes After Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction using autologous hamstring tendon grafts is a commonly performed procedure. Although the semitendinosus and gracilis tendons demonstrate regeneration at the donor site, the structural and biomechanical properties of the regenerated tissue may differ from native tendon, potentially affecting muscle function.

This study aims to quantitatively assess the elasticity of regenerated hamstring tendons using shear-wave elastography (SWE) and to compare these measurements with the contralateral intact side. Additionally, the relationship between tendon elasticity and isokinetic hamstring muscle strength will be evaluated. Secondary objectives include investigating the association between elastography findings and functional clinical outcomes, as well as the effect of postoperative time and patient-related factors such as age and body mass index.

Read the detailed description

Anterior cruciate ligament reconstruction with autologous hamstring tendon grafts, typically using the semitendinosus and gracilis tendons, is widely used in orthopedic practice. Following graft harvesting, these tendons may regenerate over time; however, the regenerated tissue often demonstrates altered histological and biomechanical characteristics, including disorganized collagen structure and reduced type I collagen content. These changes may lead to decreased tendon elasticity and impaired force transmission, potentially contributing to deficits in muscle strength and functional performance.

Shear-wave elastography (SWE) is a non-invasive imaging modality that enables quantitative assessment of tissue stiffness by measuring elastic modulus or shear-wave velocity. This technique has increasingly been used to evaluate musculoskeletal tissues and may provide objective insight into tendon regeneration quality. Isokinetic dynamometry, on the other hand, allows precise measurement of muscle strength at different angular velocities and is widely used in functional assessment after ACL reconstruction.

The primary objective of this study is to evaluate the elasticity of regenerated semitendinosus and gracilis tendons using SWE in patients who have undergone ACL reconstruction with hamstring autografts. Elastography measurements will be compared with those obtained from the contralateral intact side. Furthermore, the association between tendon elasticity and isokinetic hamstring muscle strength will be analyzed.

Secondary objectives include examining the relationship between elastography findings and functional clinical scores, including the International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores, as well as functional performance tests. The effect of postoperative duration will also be assessed by comparing early (6-12 months) and late (>12 months) postoperative periods. In addition, the influence of demographic factors such as age and body mass index on tendon elasticity and muscle strength will be evaluated.

This study is designed as a prospective cross-sectional observational study. Patients who have undergone ACL reconstruction with autologous hamstring grafts and have completed at least 6 months of postoperative follow-up will be included. Participants will undergo shear-wave elastography assessment of the hamstring tendons. Previously obtained magnetic resonance imaging (MRI) and isokinetic muscle strength (Cybex) data will be collected from institutional records. MRI will be evaluated for graft signal characteristics, tunnel position, and graft thickness, while isokinetic testing will provide quantitative measurements of hamstring strength at different angular velocities.

All data will be analyzed to determine correlations between tendon elasticity, muscle strength, imaging findings, and clinical outcomes. The findings of this study are expected to improve understanding of tendon regeneration following ACL reconstruction and may contribute to more individualized rehabilitation strategies and postoperative assessment using non-invasive biomarkers such as SWE.

Being tested
Shear-Wave Elastography Assessment
Keywords
Anterior Cruciate Ligament Reconstruction, Hamstring Tendon, Shear-Wave Elastography, Isokinetic Strength, Functional Outcomes
Medical subject headings
Anterior Cruciate Ligament Injuries, Tendon Injuries, Muscle Weakness

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Shear-Wave Elastography AssessmentOther

    Also called SWE, Elastography

    Shear-Wave elastography (SWE) will be used to quantitatively assess the elasticity of regenerated hamstring tendons. Measurement will be obtained in kilopascal (kPa) or meters per second (m/s) and compared with the contralateral intact side. These values will be analyzed in relation to isokinetic muscle strength and clinical outcomes.

Study groups in NCT07555782
Study groupRoleWhat they receive
ACL Reconstruction With Hamstring AutograftPatients who have undergone anterior cruciate ligament (ACL) reconstruction using autologous hamstring tendon grafts (semitendinosus and gracilis) and have completed at least 6 months of postoperative follow-up will be included. Participants will undergo shear-wave elastography (SWE) assessment of regenerated hamstring tendons. Previously obtained magnetic resonance imaging (MRI) and isokinetic muscle strength (Cybex) measurements will be collected from institutional records. Elastography measurements will be compared with the contralateral intact side, and associations with muscle strength, imaging findings, and functional clinical outcomes will be analyzed.
Receives: Other: Shear-Wave Elastography Assessment

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Elasticity of Regenerated Hamstring Tendons Measured by Shear-Wave Elastography

    Quantitative assessment of the elasticity of regenerated semitendinosus and gracilis tendons using shear-wave elastography (SWE). Elasticity will be measured as Young's modulus (kilopascals, kPa) or shear-wave velocity (meters per second, m/s). Measurements will be obtained from the operated limb and compared with the contralateral intact side.

    Measured: At a single postoperative assessment (≥6 months after surgery)

Secondary outcomes (8)
  1. Isokinetic Hamstring Muscle Strength

    Assessment of hamstring muscle strength using an isokinetic dynamometer (Cybex). Peak torque (Nm/kg) will be measured at angular velocities of 60°/s and 180°/s during concentric and eccentric contractions.

    Measured: At a single postoperative assessment (≥6 months after surgery)

  2. International Knee Documentation Committee (IKDC) Score

    Patient-reported knee function assessed using the IKDC subjective knee evaluation form. Scores range from 0 to 100, with higher scores indicating better function.

    Measured: At a single postoperative assessment (≥6 months after surgery)

  3. Lysholm Knee Score

    Functional knee status assessed using the Lysholm scoring system. Scores range from 0 to 100, with higher scores indicating better function.

    Measured: At a single postoperative assessment (≥6 months after surgery)

  4. Tegner Activity Scale

    Activity level assessed using the Tegner scale, ranging from 0 (sick leave or disability) to 10 (competitive sports at elite level).

    Measured: At a single postoperative assessment (≥6 months after surgery)

  5. Graft Characteristics on MRI

    Evaluation of graft characteristics on MRI, including signal intensity using a grading-based evaluation method.

    Measured: MRI obtained during postoperative follow-up (≥6 months)

  6. Femoral and Tibial Tunnel Position on MRI

    Postoperative femoral and tibial tunnel position assessed on MRI using descriptive anatomic localization and position measurements.

    Measured: MRI obtained during postoperative follow-up (≥6 months after surgery)

  7. ACL Graft Thickness on MRI

    Postoperative ACL graft thickness measured on MRI in millimeters.

    Measured: MRI obtained during postoperative follow-up (≥6 months after surgery)

  8. Postoperative Duration Group Comparison

    Comparison of tendon elasticity and muscle strength between early (6-12 months) and late (>12 months) postoperative groups.

    Measured: At a single postoperative assessment (6 and 12 months after surgery)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted29 Apr 2026
  2. Study start30 Mar 2025
  3. Primary completion30 Mar 2026
  4. Study completion30 Apr 2026

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Cross-sectional
Enrolment
29 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07555782
Sponsor's protocol ID
SWE-ACL-2026
Acronym
SWE-ACL
Status last verified
May 2026
First submitted
21 Apr 2026
Last updated
27 May 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Individual participant data (IPD) will not be shared.

Publications

  • Alp NB, Akdag G, Kaleli T, Macunluoglu AC, Uzunlulu N. Evaluation of patellar tendon with shear wave elastography after anterior cruciate ligament reconstruction using hamstring tendons. Jt Dis Relat Surg. 2020;31(1):137-42. doi: 10.5606/ehc.2020.71745.

    PubMed 32160507
  • Pasurka M, Falck T, Kubach J, Simon M, Sollner S, Strobel D, Perl M, Betsch M. Comparison of In Vivo Stiffness of Tendons Commonly Used for Anterior Cruciate Ligament Reconstruction - A Shear Wave Elastography Study. Acad Radiol. 2024 Aug;31(8):3297-3305. doi: 10.1016/j.acra.2024.01.037. Epub 2024 Feb 19.

    PubMed 38378326
  • Panagopoulos A, Giannatos V, Moros G, Mylonas D, Kouzelis A, Gliatis J. Isokinetic Muscle Strength and Knee Function in Anatomical Anterior Cruciate Ligament Reconstruction With Hamstring Autografts: A Prospective Randomized Comparative Study Between Suspensory and Expandable Femoral Fixation in Male Patients. Cureus. 2022 Dec 13;14(12):e32482. doi: 10.7759/cureus.32482. eCollection 2022 Dec.

    PubMed 36644094
  • Grasso S, Linklater J, Li Q, Parker DA. Validation of an MRI Protocol for Routine Quantitative Assessment of Tunnel Position in Anterior Cruciate Ligament Reconstruction. Am J Sports Med. 2018 Jun;46(7):1624-1631. doi: 10.1177/0363546518758950. Epub 2018 Mar 28.

    PubMed 29589954

Questions about this trial

What is this clinical trial studying?

An observational study of Anterior Cruciate Ligament Rupture and Tendon Injuries, run by Fatih Sultan Mehmet Training and Research Hospital at 1 site in Turkey (Türkiye).

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 27 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Elasticity of Regenerated Hamstring Tendons Measured by Shear-Wave Elastography (time frame: At a single postoperative assessment (≥6 months after surgery)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07555782, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 May 2026.

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