Clinical trial NCT07026188: Ultrasound Combined With SMI Imaging on Children With Limb Lengthening
Official title: Clinical Evaluation of New Bone Formation During Limb Lengthening in Children by Ultrasound Combined With Superb Microvascular Imaging
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Bone Anomalies
Lead sponsor: Children's Hospital of Fudan University
Sponsor class: OTHER
First posted: 2025-06-18
Enrollment: 63
Sex: ALL
Maximum age (years): 18
Standard ages: CHILD
ADULT
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: All are children who suffer limb length discrepancy and need limb-lengthening procedure; with no difference in sex, age or ethics.

Brief summary: In the present study, The use of ultrasound allows observation of new bone formation in the distraction gap, also visualize the formation of blood vessels in the distraction gap, including the velocity and resistance of blood vessels, and can also indicate the environment of new bone formation. It's considered that ultrasound detection of new bone and angiogenesis in the process of bone lengthening in children could be a good supplement to X-ray evaluation, and even partially replace the former, reducing the radiation burden of pediatric patients.

Detailed description: Limb lengthening is one of most common surgical techniques for correcting limb deformities in pediatric patients. The evaluation of new bone formation in the distraction gap is very important for the prognosis of limb lengthening. After limb lengthening, weekly or biweekly plain X-ray is the most commonly-used method to evaluate new bone formation in the distraction gap. However, Ordinary X-ray (film or digital) cannot provide details of regeneration or vascular regeneration like ultrasound examination, and radiation damage caused by X-ray or CT has unpredictable negative effects on minors. Ultrasound and X-ray examination were performed every 2 weeks during lengthening in 30 pediatric patients. Ultrasound was used to observe the formation of new bone, the number of vertical vessels and the blood flow resistance index, which were compared with the corresponding X-ray findings.New bone states could be divided by US into three stages: stage I (early lengthening): no obvious callus formation was found X-ray and ultrasound; stage II (lengthening stage): X-ray showed low density callus formation and uneven density, which was divided into three stages by ultrasound: IIa, punctate callus could be seen; IIb, linear callus was found, but not connected; IIc, connected linear callus was found; stage III (healing stage): the broken ends of the bone were joined, the periosteum was continuous, and the callus had disappeared. X-ray showed healing of the lengthened bone.

Eligibility criteria: Inclusion Criteria:

* All are children who suffer limb length discrepancy and need limb-lengthening procedure; with no difference in sex, age or ethics.

Exclusion Criteria:

* Space of braces is smaller than the probes.

Primary outcomes:
measure: Gray scale of US in bone gap.
timeFrame: From the first day of lengthening to the removal of the external fixator.（Approximately 6 months.）
measure: New vessels of bone gap.
timeFrame: From the first day of lengthening to the removal of the external fixator.（Approximately 6 months.）
measure: Resistance index of new vessles.
timeFrame: From the first day of lengthening to the removal of the external fixator.（Approximately 6 months.）
measure: Healing index
timeFrame: From the first day of lengthening to 2 months after the removal of the external fixator.（Approximately 8 months.）
Secondary outcomes:
Other outcomes:
Locations:
city: Shanghai
country: China
facility: Children's Hospital of Fudan University
Study officials:
affiliation: Pediatric hospital of Fudan University
name: Ning Bo, MD
role: PRINCIPAL_INVESTIGATOR
References: