Clinical and Functional Outcomes After Subtalar Arthroereisis in Pediatric Flexible Flatfoot

Condition(s) studied

Investigational drug(s) / intervention(s)

Subtalar Arthroereisis: A conical titanium implant is inserted into the sinus tarsi through a minimally invasive approach to restrict excessive subtalar pronation while preserving joint mobility. Implant size and position are assessed clinically and under fluoroscopic guidance. Additional soft-tissue or navicular procedures may be performed when clinically indicated, including gastrocnemius lengthening; excision or regularization of a symptomatic accessory or prominent navicular; posterior tibial tendon reinsertion or retensioning; or anterior tibial tendon tenosuspension according to the Young technique. These procedures are determined by clinical need and are not assigned by the study protocol.

Study summary

Flexible flatfoot is common in children and adolescents. In some patients, the condition remains painful or limits activity despite non-surgical treatment. Subtalar arthroereisis is a minimally invasive operation in which an implant is placed in the sinus tarsi to limit excessive foot pronation while preserving joint movement.

This observational study follows children and adolescents who receive subtalar arthroereisis as part of their planned clinical care. Clinical status, standing foot radiographs, plantar-pressure distribution, and walking characteristics are assessed before surgery and six months after surgery. The study aims primarily to describe changes in dynamic plantar loading and walking parameters. Changes in clinical scores and radiographic alignment are assessed as secondary outcomes. No treatment is assigned for research purposes, and all surgical and postoperative decisions are made according to routine clinical indications.

Eligibility

Primary outcome measure(s)

• Step-Cycle Duration — Baseline and 6 months after surgery
• Ground-Contact Duration — Baseline and 6 months after surgery
• Double-Support Duration — Baseline and 6 months after surgery
• Step Length — Baseline and 6 months after surgery
• Anteroposterior Talonavicular Coverage Angle Measured on Weight-Bearing Radiographs Using Synapse — Baseline and 6 months after surgery
  The anteroposterior talonavicular coverage angle will be measured in degrees using the Synapse software on radiographic images. The measurement will be performed at baseline, before surgery (T0), and approximately 6 months after surgery (T1), in the operated foot. The change from baseline to 6 months after surgery will be evaluated.
• Anteroposterior Talocalcaneal Angle Measured Using Synapse — Baseline and 6 months after surgery
  The anteroposterior talocalcaneal angle will be measured in degrees using the Synapse software on radiographic images. The measurement will be performed at baseline, before surgery (T0), and approximately 6 months after surgery (T1), in the operated foot. The change from baseline to 6 months after surgery will be evaluated.
• Lateral Meary's Angle Measured Using Synapse — Baseline and 6 months after surgery
  The lateral Meary's angle will be measured in degrees using the Synapse software on radiographic images. The measurement will be performed at baseline, before surgery (T0), and approximately 6 months after surgery (T1), in the operated foot. The change from baseline to 6 months after surgery will be evaluated.
• Lateral Calcaneal Pitch Measured Using Synapse — Baseline and 6 months after surgery
  The lateral calcaneal pitch will be measured in degrees using the Synapse software on radiographic images. The measurement will be performed at baseline, before surgery (T0), and approximately 6 months after surgery (T1), in the operated foot. The change from baseline to 6 months after surgery will be evaluated.

Trial sites (1)

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