Quantifying Patellar Tendon Microstructure Using DTI

Quantifying Patellar Tendon Microstructure Using Diffusion Tensor Imaging

The goal of this observational study is to understand how diffusion tensor imaging (DTI) relates to other traditional measures and knee function. The main question it aims to answer is:

Will regions of known patellar tendon pathology present with smaller DTI scalar parameters, shorter fiber length, and lower fiber density compared to the contralateral tendon and healthy regions in the ipsilateral tendon.

Participants will:

• undergo MRI and ultrasound imaging
• perform knee function test
• complete questionnaires

Study Overview

• Status: Completed
• Conditions: Anterior Cruciate Ligament Reconstruction; Patellar Tendinopathy
• Intervention / Treatment: Device: MRI; Device: Ultrasound (US); Device: Neuromuscular electric stimulation (NMES)

Detailed Description

Patellar tendon injuries are commonly accompanied by macrostructural alterations captured on common imaging modalities, and the extent of these alterations correlate to knee joint function. Evidence for using tendon macrostructure for diagnosis and prognosis of tendon injuries is not as clear, suggesting that these imaging modalities are not providing a complete picture of the alterations. Diffusion tensor imaging (DTI) tractography can quantify tendon microstructures that underlie the alterations in pathological tendons and shows promising results in healthy tendons. This study is the first step in evaluating whether tendon microstructure captured using DTI technology can be applied as a biomarker to optimize treatment for patellar tendon injuries.

• Study Type: Observational
• Enrollment (Actual): 62

Contacts and Locations

Study Locations

• United States
  • Wisconsin
    • Madison, Wisconsin, United States, 53705
      • University of Wisconsin - Madison

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Cases: Adults 18 years or older with a diagnosis of patellar tendinopathy, or with a history of anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone autograft.

Controls: Adults 18 years or older without a diagnosis of patellar tendinopathy or history of ACL reconstruction using bone-patellar tendon-bone autograft

Description

Inclusion Criteria:

• Age 18 or older
• Have patellar tendon injury as confirmed through subjective report, clinical examination, and ultrasound by an experienced physical therapist
• Patellar tendinopathy group must present with current symptoms of patellar tendinopathy
• Control group must have no history of patellar tendon injury

Exclusion Criteria:

• Participants with a history of invasive procedures other than bone-patellar tendon-bone (BPTB) autograft harvest to the patellar tendon or extensor mechanism
• Participants with history of contralateral BPTB autograft harvest, or ACLR using any other graft type
• Participants with contraindications to MRI
• Participants with contraindications to NMES

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Bone-patellar tendon-bone (BPTB); This group will have patellar injury confirmed through self-reported surgical history and evidence of ipsilateral BPTB graft harvest on ultrasound.	Device: MRI; MRI using DTI technology; Device: Ultrasound (US); Standard US; Device: Neuromuscular electric stimulation (NMES); Standard NMES
Patellar tendinopathy group; This group will have patellar tendinopathy confirmed based on International Scientific Tendinopathy Symposium Consensus on Clinical Terminology (ICON) statement, which defines patellar tendinopathy as "persistent patellar tendon pain and loss of function related to mechanical loading." Ultrasound diagnosis must confirm alteration of tendon macrostructure.	Device: MRI; MRI using DTI technology; Device: Ultrasound (US); Standard US; Device: Neuromuscular electric stimulation (NMES); Standard NMES
Healthy knees; Control group of participants with healthy knees	Device: MRI; MRI using DTI technology; Device: Ultrasound (US); Standard US; Device: Neuromuscular electric stimulation (NMES); Standard NMES

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Compare scalar parameters of known patellar tendon pathology to the contralateral tendon	DTI parameters will be obtained by built-in diffusion-weighted sequences on the GE MRI machine. Regions of interest will be selected using clinical scans, and region specific DTI parameters will be compared between regions and over the repeat test sessions	Up to 2 weeks
Compare DTI scalar parameters of known patellar tendon pathology to the healthy regions in the ipsilateral tendon	DTI parameters will be obtained by built-in diffusion-weighted sequences on the GE MRI machine. Regions of interest will be selected using clinical scans, and region specific DTI parameters will be compared between regions and over the repeat test sessions	Up to 2 weeks
Rank patellar tendon loads during exercise	Patellar tendon loads will be obtained by tensiometer measurements during common exercises for patellar tendon rehabilitation while subject wears NMES sensors. Patellar tendon loads will be compared between regions and over the repeat test sessions.	Up to 2 weeks

Collaborators and Investigators

• Sponsor: University of Wisconsin, Madison
• Collaborators: National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
• Investigators: Principal Investigator: Bryan Heiderscheit, PT, PhD, University of Wisconsin, Madison; Principal Investigator: Daniel Cobian, DPT, PhD, University of Wisconsin, Madison

Study record dates

Study Major Dates

• Study Start (Actual): May 21, 2024
• Primary Completion (Actual): December 27, 2025
• Study Completion (Actual): December 27, 2025

Study Registration Dates

• First Submitted: April 19, 2024
• First Submitted That Met QC Criteria: April 19, 2024
• First Posted (Actual): April 24, 2024

Study Record Updates

• Last Update Posted (Actual): January 8, 2026
• Last Update Submitted That Met QC Criteria: January 6, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Muscular Diseases; Wounds and Injuries; Tendon Injuries; Tendinopathy; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Imaging; Ultrasonography
• Other Study ID Numbers: 2024-0057; A536130 (Other Identifier: UW Madison); SMPH/ORTHO&REHAB/PHYS THER (Other Identifier: UW Madison); 1K99AR085752-01 (U.S. NIH Grant/Contract); Protocol Version 10/1/2025 (Other Identifier: UW Madison)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No