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Enrolling by Invitation

NCT Number: NCT07212049

Ultrasound Use to Measure Magnetically Controlled Growing Rods

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

Enrolling by Invitation

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Key information

Conditions

Limb Length Discrepancy

Age range

8 year–21 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Nemours Children's Hospital Florida

Orlando, Florida, 32827, United States

About this study

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

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

Exclusion criteria

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

Treatment and study plan

ultrasound measurement

Device

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 femur

Diagnostic Test

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.

Other names: Radiographs

Primary outcomes

  1. Ultrasound Measurement of the lengthening rod

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

    ultrasound measurement of the length of the internal lengthening rod

  2. X-ray measurement of the lengthening rod

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

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

Secondary outcomes

  1. Cost of imaging

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

    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.

  2. Pain reported during imaging

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

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

Sponsors and collaborators

Lead sponsor

Nemours Children's Clinic

Other

Registry information

Official study title

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

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Oct 21, 2025
Registry last updated
Nov 3, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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