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Limb Length DiscrepancyNCT07212049

Ultrasound Use to Measure Magnetically Controlled Growing Rods

A study testing ultrasound measurement and X-ray imaging of tibia and/or femur in people with Limb Length Discrepancy, run by Nemours Children's Clinic at 1 site in United States.

Enrolling by invitation

Enrolling by invitation. The study team selects and invites participants, usually from an existing group of patients.

Sites and contacts
Official record
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Trial summary

The goal of this clinical trial is to learn if an ultrasound can measure the length of an internal tibia and femur lengthening rod. The main questions it aims to answer are: Can an ultrasound be used to measure the length of an internal magnetic lengthening nail in a tibia or femur? Can an ultrasound measure the rod… Read more about this study

Who is it for?
Ages 8 to 21 yearsHealthy volunteers can take part
Conditions the study is for
Limb Length Discrepancy
What is being tested?
ultrasound measurement and X-ray imaging of tibia and/or femur
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
10 participants
Where
1 siteUnited States
Study dates
5 Sep 2025to 5 Sep 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

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 8 to 21 years
  • All sexes
  • Healthy volunteers accepted
  • Child, Adult

Who may be able to join

  • Patients undergoing tibia or femur lengthening with an intramedullary mechanical rod.

Who cannot join

  • Patients who underwent lengthening procedure with any other device such as external fixator.
  • Patients under 8 years old and over 21 years of age

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

United States1 site
  • Nemours Children's Hospital Florida

    Orlando, Florida, 32827

Other trials in United States

About this study

Official title: Using Ultrasound as an Alternative to Radiography in Measuring Magnetically Controlled Growing Rods (MCGR) in Tibia and Femur Lengthening Patients

The goal of this clinical trial is to learn if an ultrasound can measure the length of an internal tibia and femur lengthening rod. The main questions it aims to answer are:

Can an ultrasound be used to measure the length of an internal magnetic lengthening nail in a tibia or femur? Can an ultrasound measure the rod lengthening as well as an ultrasound? Researchers will compare the length of an internal magnetic lengthening rod with both x-rays and ultrasound

Participants will:

Have standard x-rays every week They will also have an ultrasound of the femur or tibia

Read the detailed description

Limb lengthening with expanding intramedullary rods has become the standard of care for limb lengthening procedures. The procedure entails performing an osteotomy of the short bone and placing a mechanical expanding intramedullary nail. The aim of the study is to explore the role of ultrasound to measure tibia and femur lengthening procedures and compare the accuracy to standard radiographs.

The study design is a prospective, pilot study of 5 tibias and 5 femurs. Measurements of the femurs and tibias will be obtained in 3 separate locations to try to identify areas that can be visualized and measured by an ultrasound. The cost of the ultrasound will be compared to the cost of x-rays, and any pain regarding imaging modalities will also be compared

Being tested
ultrasound measurement, X-ray imaging of tibia and/or femur
Keywords
limb lengthening, leg length difference

What participants receive

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

  • ultrasound measurementDevice

    Three different measurements will be obtained using an ultrasound to determine the length gained from lengthening the tibia and/or femur with an internal lengthening rod. Please see the protocol on the locations that will me measured.

  • X-ray imaging of tibia and/or femurDiagnostic test

    Also called Radiographs

    All patients will have an x-ray with two views anterior-posterior and lateral to measuring the lengthening of the internal rod. Please see the protocol for locations of the measurements being obtained.

Study groups in NCT07212049
Study groupRoleWhat they receive
Ultrasound of lengthening rodExperimentalAll patients will have an ultrasound measuring the lengthen of the internal rod
Receives: Device: ultrasound measurement; Diagnostic Test: X-ray imaging of tibia and/or femur

What is being measured

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

  1. Ultrasound Measurement of the lengthening rod

    ultrasound measurement of the length of the internal lengthening rod

    Measured: Once a week during the lengthening process, up to 10 weeks

  2. X-ray measurement of the lengthening rod

    X-ray measurement of the internal lengthening rod at three points on the rod.

    Measured: Once a week during the lengthening process, up to 10 weeks

Secondary outcomes (2)
  1. Cost of imaging

    The cost of ultrasound and x-rays. The ultrasound has no cost as it is a point-of-care device. The x-ray cost will derived from the mast charge that is post online for Nemours Children's Hospital Florida. The cash charge for a tibia two view x-ray is $471. The cash charge for a femur two view x-ray is $282.

    Measured: Once a week during the lengthening process, up to 10 weeks

  2. Pain reported during imaging

    Pain experienced will measured with Wong-Baker faces pain rating scale during imaging with x-ray and ultrasound

    Measured: Once a week during the lengthening process, up to 10 weeks

Timeline

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

  1. First posted21 Oct 2025
  2. Study start5 Sep 2025
  3. Primary completion5 Sep 2027 (estimated)
  4. Study completion5 Sep 2027 (estimated)

Resources

More details

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

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Diagnosis
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
10 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07212049
Sponsor's protocol ID
2169786
Status last verified
Sep 2026
First submitted
8 Sep 2025
Last updated
9 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
No

Publications

  • Stokes OM, O'Donovan EJ, Samartzis D, Bow CH, Luk KD, Cheung KM. Reducing radiation exposure in early-onset scoliosis surgery patients: novel use of ultrasonography to measure lengthening in magnetically-controlled growing rods. Spine J. 2014 Oct 1;14(10):2397-404. doi: 10.1016/j.spinee.2014.01.039. Epub 2014 Jan 31.

    PubMed 24486476
  • Cobanoglu M, Shah SA, Gabos P, Rogers K, Yorgova P, Neiss G, Grissom L, Mackenzie WG. Comparison of Intended Lengthening of Magnetically Controlled Growing Rods: Ultrasound Versus X-Ray. J Pediatr Orthop. 2019 Feb;39(2):e141-e146. doi: 10.1097/BPO.0000000000001072.

    PubMed 29016427
  • Yoon WW, Chang AC, Tyler P, Butt S, Raniga S, Noordeen H. The use of ultrasound in comparison to radiography in magnetically controlled growth rod lengthening measurement: a prospective study. Eur Spine J. 2015 Jul;24(7):1422-6. doi: 10.1007/s00586-014-3589-z. Epub 2014 Sep 26.

    PubMed 25256680
  • Cheung JP, Bow C, Samartzis D, Ganal-Antonio AK, Cheung KM. Clinical utility of ultrasound to prospectively monitor distraction of magnetically controlled growing rods. Spine J. 2016 Feb;16(2):204-9. doi: 10.1016/j.spinee.2015.10.044. Epub 2015 Oct 30.

    PubMed 26523963
  • Schiedel FM, Buller TC, Rodl R. Estimation of patient dose and associated radiogenic risks from limb lengthening. Clin Orthop Relat Res. 2009 Apr;467(4):1023-7. doi: 10.1007/s11999-008-0624-6. Epub 2008 Nov 22.

    PubMed 19030942
  • Laubscher M, Mitchell C, Timms A, Goodier D, Calder P. Outcomes following femoral lengthening: An initial comparison of the Precice intramedullary lengthening nail and the LRS external fixator monorail system. Bone Joint J. 2016 Oct;98-B(10):1382-1388. doi: 10.1302/0301-620X.98B10.36643.

    PubMed 27694593

Questions about this trial

What is this clinical trial studying?

A study testing ultrasound measurement and X-ray imaging of tibia and/or femur in people with Limb Length Discrepancy, run by Nemours Children's Clinic at 1 site in United States.

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 1 inclusion and 2 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: enrolling by invitation, as of the sponsor's last update on 9 Sep 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 United States. 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?

This study is still under way. Results are not available in the source record yet.

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?

Ultrasound Measurement of the lengthening rod (time frame: Once a week during the lengthening process, up to 10 weeks). The study lists 2 primary outcomes in all. 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 NCT07212049, which also lists 6 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 9 Sep 2026.

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