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.
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
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
- Conditions
- Limb Length Discrepancy
- 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 group | Role | What they receive |
|---|---|---|
| Ultrasound of lengthening rod | Experimental | All 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.
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
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)
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
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.
- First posted21 Oct 2025
- Study start5 Sep 2025
- Primary completion5 Sep 2027 (estimated)
- Study completion5 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Limb Length DiscrepancyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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)
Sponsor and investigators
- Lead sponsor
- Nemours Children's Clinic
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jason Malone, Nemours Children's Clinic
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 24486476Cobanoglu 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 29016427Yoon 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 25256680Cheung 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 26523963Schiedel 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 19030942Laubscher 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
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Using Ultrasound as an Alternative to Radiography in Measuring Magnetically Controlled Growing Rods (MCGR) in Tibia and Femur Lengthening Patients
- ClinicalTrials.gov ID
- NCT07212049
- Acronym / sponsor ID
- 2169786
- Conditions
- Limb Length Discrepancy
- Keywords
- limb lengthening, leg length difference
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 10 participants (estimated)
- Lead sponsor
- Nemours Children's ClinicUniversity, hospital or other
- Study start
- 5 Sep 2025 (actual)
- Primary completion
- 5 Sep 2027 (estimated)
- Study completion
- 5 Sep 2027 (estimated)
- First posted
- 21 Oct 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
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
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Ultrasound of lengthening rod | Experimental | Device: ultrasound measurement, Diagnostic Test: X-ray imaging of tibia and/or femurAll patients will have an ultrasound measuring the lengthen of the internal rod |
Who may qualify
- Ages
- 8 to 21 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (1 listed)
- Patients undergoing tibia or femur lengthening with an intramedullary mechanical rod.
Key exclusion criteria (2 listed)
- Patients who underwent lengthening procedure with any other device such as external fixator.
- Patients under 8 years old and over 21 years of age
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ultrasound measurementThree 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. | Device | Ultrasound of lengthening rod |
| X-ray imaging of tibia and/or femurAlso: RadiographsAll 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. | Diagnostic test | Ultrasound of lengthening rod |
Primary outcome
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
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.
2 secondary outcomes
Cost of imaging
Time frame: Once a week during the lengthening process, up to 10 weeks
Pain reported during imaging
Time frame: Once a week during the lengthening process, up to 10 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2026.
- Background: PubMed 24486476Stokes 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.
- Background: PubMed 29016427Cobanoglu 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.
- Background: PubMed 25256680Yoon 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.
- Background: PubMed 26523963Cheung 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.
- Background: PubMed 19030942Schiedel 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.
- Background: PubMed 27694593Laubscher 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.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
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.