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RecruitingNCT07569835ARTRO-LONGUpdated May 6, 2026

Clinical and Radiological Evaluation Over 10 Years After Bilateral Subtalar Arthrorisis Surgery With Endorthesis and Calcaneal Stop for the Correction of Pediatric Flatfoot

An observational study in Flat Foot Acquired Bilateral (Pes Planus), sponsored by Istituto Ortopedico Rizzoli. Recruiting at 1 site in Italy. Per ClinicalTrials.gov, last updated 2026-05-06.

Sponsored by Istituto Ortopedico Rizzoli · Observational

From the registry’s dates

  • Started May 2024; still recruiting 2 years 5 months later.
Study type
Observational
Model
Case-only
Time perspective
Retrospective
Enrollment
20
Sex
All
01

Study summary

VARIABLES TO BE COLLECTED AND SOURCE The primary efficacy endpoint will be the maintenance of flatfoot correction over time, assessed both clinically (tip-toe test, Jack test, tip-toe walking test) and radiologically (evaluation of Meary's angle on the lateral foot view and the talocalcaneal angle).

The secondary efficacy endpoint will be the absence of pain at follow-up, assessed using the VAS scale, and evaluation of the footprint using a podoscope.

TIP-TOE TEST:

The patient is observed under weight-bearing conditions and then while rising onto the toes. If the foot is flexible, the plantar arch-previously absent-reappears when standing on tip-toe.

JACK TEST:

This consists of passive dorsiflexion of the hallux under weight-bearing conditions. If the previously absent arch reappears, the flatfoot is considered flexible.

TIP-TOE WALKING TEST:

The patient walks for about ten steps on tip-toe. The examiner observes any varus alignment of the hindfoot and reconstruction of the plantar arch.

MEARY'S ANGLE:

Measured between the longitudinal axis of the talus and that of the first metatarsal on a weight-bearing lateral foot radiograph.

TALOCALCANEAL ANGLE:

Measured between the longitudinal axis of the talus and that of the calcaneus on a weight-bearing dorsoplantar foot radiograph.

VAS:

The Visual Analog Scale for pain is a tool used to measure the subjective characteristics of pain experienced by the patient, ranging from 0 (no pain) to 10 (worst imaginable pain).

PODOSCOPE FOOTPRINT ASSESSMENT:

Evaluation of the isthmus (the narrow portion of the footprint connecting the heel to the forefoot). The foot is considered normal when the width of the isthmus is between one-third and one-half of the maximum width of the forefoot.

SAMPLE SIZE AND STATISTICS In Prof. Giannini's study, 30 patients were enrolled; approximately 30% were lost to follow-up over 12 years. Barring further losses, about 20 patients currently followed at Clinic I are expected to be available.

ENROLLMENT PROCEDURE Eligible patients will be enrolled in the study only after providing written informed consent. No data collection, procedures, or analyses will be performed prior to obtaining consent.

DATA COLLECTION Clinical data required for the study will be extracted from patients' medical records and source documents.

A dedicated data collection form will be used to record clinical information and the results of the analyses by the study.

For each enrolled patient, a Case Report Form (CRF) will be completed.

02

Conditions studied

  • Flat Foot Acquired Bilateral (Pes Planus)

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03

In context

Flatfoot

173 studies on the registry are indexed under Flatfoot; 44 are open to participants now.

This study's planned enrollment of 20 is below the median of 47 across 48 observational studies indexed under Flatfoot.

Browse Flatfoot studies →

Lead sponsor

Istituto Ortopedico Rizzoli is the lead sponsor of 304 studies on the registry; 103 are open to participants now.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
Child (0–17), Adult (18–64), Older adult (65+)
Sexes eligible
All
Sampling method
Non-probability sample

Study population

Primary objective:

To evaluate, at more than ten years' follow-up, the clinical and radiological outcomes of patients who underwent subtalar arthroereisis with calcaneostop and endorthosis for the correction of pediatric flatfoot.

Secondary objectives:

To compare, within the same patient, the clinical and radiological outcomes of feet treated with subtalar arthroereisis using calcaneostop versus endorthosis.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Patients already in follow-up after undergoing subtalar arthroereisis with calcaneostop and endorthosis, enrolled in the study "Flatfoot treatment: comparison between resorbable endorthosis and resorbable calcaneal stop" by Prof. Giannini, still in follow-up at IOR.

Exclusion criteria

EXCLUSION CRITERIA:

Patients who have undergone subsequent surgical procedures on the foot and ankle

05

Study design

Observational model
Case-only
Time perspective
Retrospective
Enrollment
20 participants (estimated)
Patient registry
No

Groups and cohorts

  • patients who underwent subtalar arthroereisis with calcaneostop and endorthosis

    Other: calcaneo stop and endorthesis

Interventions

  • Othercalcaneo stop and endorthesis

    To evaluate, at more than ten years' follow-up, the clinical and radiological outcomes of patients who underwent subtalar arthroereisis with calcaneostop and endorthosis for the correction of pediatric flatfoot.

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What researchers measure

Primary outcomes

  1. VAS (Visual Analog Scale)

    A scale used to measure the subjective characteristics of pain experienced by the patient, ranging from 0 (no pain) to 10 (worst imaginable pain).

    Time frame: may 2024 may 2027

Secondary outcomes

  1. MEARY'S ANGLE

    Measured between the axis of the talus and that of the first metatarsal on a weight-bearing lateral foot radiograph

    Time frame: may 2024 may 2027

  2. TALO-CALCANEAL ANGLE

    Measured between the axis of the talus and that of the calcaneus on a weight-bearing dorsoplantar foot radiograph.

    Time frame: may 2024 may 2027

  3. TIP-TOE TEST

    The patient is observed under weight-bearing conditions and then while rising onto the toes. If the foot is flexible, the plantar arch-previously absent-reappears when standing on tiptoe.

    Time frame: may2024 - may 2027

  4. jACK TEST

    this consists of passive extension of the big toe under weight-bearing. If the previously absent arch reappears, the flatfoot is flexible.

    Time frame: may 2024 - may 2027

  5. TIPTOE WALKING

    The patient walks for about ten steps on tiptoe, and the examiner observes any varus alignment of the hindfoot and the reformation of the plantar arch.

    Time frame: may 2024 - may 2027

  6. PODOSCOPE FOOTPRINT ASSESSMENT

    Evaluation of the isthmus (the narrow portion of the footprint connecting the heel to the forefoot). The foot is considered normal when the width of the isthmus is between one-third and one-half of the maximum width of the

    Time frame: may 2024 - may 2027

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Study locations

1 of 1 sites recruiting
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 6, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT07569835
Responsible party
Antonio Mazzotti (Principal Investigator, Istituto Ortopedico Rizzoli) — Principal investigator
First posted
May 6, 2026
Start date
May 30, 2024
Primary completion
Apr 21, 2026
Completion
May 2026 (estimated)
Last update
May 6, 2026

Study contacts

Antonio Mazzotti Prof
Contact
antonio.mazzotti@ior.it
+39 3498798863

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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