Using a sinus tarsi implant to improve surgery for flatfoot deformity

Sinus Tarsi Implant as an Adjuvant Procedure to Medial Displacement Calcaneal Osteotomy in the Treatment of Mobile Adult Acquired Flatfoot Deformity: a Randomized Controlled Trial

PHASE4 · Region Skane · NCT06211504

This study is testing if a new implant can help improve surgery results for adults with flatfoot deformity by providing better support and alignment.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment130 (estimated)
Ages16 Years to 75 Years
SexAll
SponsorRegion Skane (other)
Locations10 sites (Hässleholm, Skåne County and 9 other locations)
Trial IDNCT06211504 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the effectiveness of a sinus tarsi implant (STI) as an adjuvant procedure to medial displacement calcaneal osteotomy (MDCO) for treating mobile adult acquired flatfoot deformity (AAFD). The study aims to address the limitations of MDCO, which only corrects the deformity in one plane, by using the STI to provide additional support and improve overall foot alignment. Conducted as a multicenter randomized controlled trial across nine orthopedic centers in Sweden, patients will be evaluated and treated based on specific eligibility criteria. The trial seeks to determine if the STI can enhance surgical outcomes and long-term functional results for patients suffering from AAFD.

Who should consider this trial

Good fit: Ideal candidates for this study are individuals aged 16-75 with stage IIA AAFD who have not responded to non-surgical treatments.

Not a fit: Patients with previous surgeries for AAFD, severe joint conditions, or other significant health issues may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could lead to improved surgical outcomes and better long-term function for patients with flatfoot deformity.

How similar studies have performed: While the use of sinus tarsi implants is a relatively novel approach, similar studies have shown promise in improving surgical outcomes for foot deformities.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients with AAFD stage II, in whom the talonavicular uncoverage is not considered by the treating surgeon to require an additional lateral column lengthening
* Age 16-75 years, either sex
* Failed non-surgical treatment including 3 months of physiotherapy

Exclusion Criteria:

* Previous ipsilateral surgery for AAFD
* General hypermobility (Beighton score \> 6)
* Osteoarthritis in the hindfoot joints, ankle joint or first tarsometatarsal joint
* Rheumatoid arthritis
* Inability to answer patient-reported outcome measures (PROMs) due to language difficulties or cognitive disorder
* Current smoker
* Current pregnancy
* Severe medical illness
* Known abuse of drugs and/or alcohol
* Previous ipsilateral hindfoot fracture including Lisfranc injury

Where this trial is running

Hässleholm, Skåne County and 9 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Acquired Adult Flatfoot Deformity, Flat Foot, Flexible Flatfoot, AAFD, RCT, clinical trial, surgical intervention, arthroereisis

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.