ClinicalTrials.gg
RecruitingNCT05555459Updated Mar 13, 2026

Performance and Safety Evaluation of Inion CompressOn Screw in Foot and Ankle Surgeries. PMCF Investigation

An interventional study of Operation in Medial Malleolus Fracture, Lisfranc Injury and Lisfranc Fracture, sponsored by Inion Oy. Recruiting at 1 site in Finland. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-13.

Sponsored by Inion Oy · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Started Mar 2023; still recruiting 3 years 8 months later.
Phase
Not applicable
Study type
Interventional
Enrollment
125
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

The study in question is a post market clinical follow up (PMCF) study to evaluate the safety and performance of bioabsorbable headless compression screw Inion CompressOn in selected fracture, osteotomy and arthrodeses operations of the foot and ankle. The study recruits 125 adult patients who meet the acceptance criteria. The follow-up time for each study patient is 4 years. The study is a single center single group study which is conducted in Tampere University Hospital (TAYS) in Finland. The main focus of the study in terms of performance is to evaluate the bone healing/ossification of operated areas. The main focus of the study in terms of safety is to evaluate the occurrence of adverse events and required revision surgeries that are or might be related to the study device.

Read the detailed description

The study in question is a post market clinical follow-up study to evaluate the safety and performance of bioabsorbable headless compression screw Inion CompressOn in selected fracture, osteotomy and arthrodeses operations of the foot and ankle. The main focus of the study in terms of performance is to evaluate the bone healing/ossification of operated areas. The main focus of the study in terms of safety is to evaluate the occurrence of adverse events and required revision surgeries that are or might be related to the study device.

The Inion CompressOn™ screws are cannulated headless compression screws made of degradable co-polymers composed of L-lactic acid and D-lactic acid. These polymers have a long history of safe medical use and they degrade in vivo by hydrolysis into alpha-hydroxy acids that are metabolised by the body. The screws retain their initial strength up to 12 weeks after implantation and gradually lose their strength thereafter. Bioabsorption takes place within two to four years. The Inion CompressOn™ products are intended for maintenance of alignment and fixation of bone fractures, comminuted fractures, osteotomies, arthrodeses or bone grafts (i.e., autografts or allografts) in the presence of appropriate additional immobilization (e.g., rigid fixation implants, cast or brace).

In the field of foot and ankle traumatology the surgical indications of this study include medial malleolar fractures, Lisfranc injuries, talus fractures, calcaneal fractures and navicular bone fractures. In the field of foot and ankle orthopaedics the surgical indications of the study include arthrodesis of the talonavicular joint, calcaneacuboideal joint, tarsometatarsal joint and first metatarsophalangeal (MTP1) joint, and osteotomies of the first metatarsal bone, second metatarsal bone (weil) and calcaneal bone.

The clinical data collection acquired from this study is a requirement of the EU Notified Body as part of the admitted CE mark certification, in cases when the device is initially approved based on the clinical data of an equivalent device. In this case, the equivalent device has been Inion FreedomScrew, which is made of the same material composition and has the same indications for use. Inion CompressOn Screw has new design features such as headless design, and threading which allows compression to the fracture line. Also new sizes are introduced.

The study recruits 125 adult patients who meet the acceptance criteria and have signed the informed consent. The follow-up time for each study patient is 4 years. Each patient has 6 follow-up time points related to the study. These time points consist of:

  1. screening visit (-180-0 days before operation),
  2. operation (day 0),
  3. post-operative follow-up 1 (6 weeks after operation +/- 1 week),
  4. post-operative follow-up 2 (3 months after operation +/- 2 weeks),
  5. post-operative follow-up 3 (2 years after operation +/- 2 months)
  6. post-operative follow-up 4 (4 years after operation +/- 4 months) The first 4 time points are within standard care, the last 2 time points (post-operative follow-up 3 and post-operative follow-up 4) are scheduled for study purposes only to be able to gain performance and safety data based on adequate follow-up time.

The study is a single center single group study which is conducted in Tampere University Hospital (TAYS) in Finland.

02

Conditions studied

  • Medial Malleolus Fracture
  • Lisfranc Injury
  • Lisfranc Fracture
  • Talus Fracture
  • Calcaneus Fracture
  • Navicular Fracture
  • Deformity, Foot
  • Ankle Fractures
  • Foot Fracture
  • Fractures, Bone
  • Fracture of Foot
  • Foot Deformities
  • Foot Injury
  • Feet Deformity Tarsus
  • Metatarsalgia
  • Hallux Rigidus
  • Hallux Valgus
  • Deformity of Toe
  • Deformity of Foot

Keywords

  • bioabsorbable screw
  • compression screw
  • headless screw
  • orthopaedic screw
  • bone fixation
  • bioabsorbable screw study
  • resorbable
  • biodegradable
  • bioabsorbable
  • fracture fixation with resorbable implants
  • inion
  • post-market follow-up study
  • orthopedic bone fixation
  • arthrodesis
  • osteotomy
03

In context

Ankle Fractures

202 studies on the registry are indexed under Ankle Fractures; 44 are open to participants now.

This study's planned enrollment of 125 is above the median of 90 across 150 interventional studies indexed under Ankle Fractures.

Browse Ankle Fractures studies →

Lead sponsor

Inion Oy is the lead sponsor of 4 studies on the registry; 2 are open to participants now.

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

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

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

  1. Read the patient information bulletin on the study and signed the patient consent form
  2. Adult patient (over 18-year-old)
  3. Suitable and in need for surgical lower limb operation listed in the indications of this study that requires fastening of bone structures with screws (or an alternative attachment method) in the ankle or foot area, according to a statement of the investigator surgeon
  4. Ability to fill in questionnaires.
  5. Willingness to comply with rehabilitation instructions.
  6. Availability for follow-up visits.

Exclusion criteria

Exclusion Criteria:

  1. Active infection
  2. Patient conditions including limited blood supply (e.g. patients with severe circulatory disorder of the lower limb
  3. Patient conditions including insufficient quality or quantity of bone (diagnosed osteoporosis, conditions causing secondary osteoporosis e.g. diabetes, rheumatism, eating disorder)
  4. Patient conditions where patient cooperation cannot be guaranteed (alcohol use, drug abuse etc.)
  5. High-load bearing indications (e.g., diaphyseal fractures of long bones) unless used in conjunction with traditional rigid fixation
  6. Patients with significant neuropathy
  7. Pregnancy
  8. Patients who refuse to participate
  9. Lower limb tumor or
  10. Complex Regional Pain Syndrome (CRPS) in operated foot
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
125 participants (estimated)

Study arms

  • Experimental
    CompressOn group

    125 participant patients undergoing bone fixation surgical operation specified in the study description. All bone fixation surgeries are performed using Inion CompressOn screws.

    Procedure: Operation

Interventions

  • ProcedureOperation

    Bone fixation operation in foot or ankle area using bioabsorbable headless screw/s

06

What researchers measure

Primary outcomes

  1. Bone healing (ossification) of the fracture, osteotomy and arthrodesis lines

    X-ray evaluation of bone healing (ossification) of the fracture, osteotomy and arthrodesis lines

    Time frame: Change from operation to 4 years

  2. Occurrence of adverse events (AEs)

    Assessment of occurrence of adverse events (AE), such as non-union of bone, fixation failure, mechanical irritation and tissue reactions related to implant bioabsorption

    Time frame: During 4-year follow-up

  3. Occurrence of revision surgeries

    Assessment of occurrence of revision surgeries related to study device

    Time frame: During 4-year follow-up

Secondary outcomes

  1. Subjective functionality of the operated foot or ankle (VAS foot and ankle)

    Evaluation of subjective pain of the operated foot or ankle during follow-up

    Time frame: Change from baseline to 4 years

  2. Subjective functionality of the operated foot or ankle (EFAS)

    Evaluation of subjective functionality of the operated foot or ankle during follow-up

    Time frame: Change from baseline to 4 years

  3. Wound and soft tissue healing

    Assessment of post-operative complications (wound and soft tissue healing based on inspection and palpation)

    Time frame: Change from operation to 3 months

  4. Fixation strength

    X-ray evaluation of the maintaining of fixation position

    Time frame: Change from operation to 4 years

  5. Bone formation in screw tunnel

    X-ray evaluation of the level of bone formation in screw tunnel

    Time frame: Change from operation to 4 years

07

Study locations

1 of 1 sites recruiting
  • Tampere University Hospital
    Tampere, 33520, Finland
    Recruiting
    • Heikki Mäenpää, MD · Contactheikki.maenpaa@pshp.fi · +358 3 311 611
    • Nikke Partio, MD · Sub investigator
    • Outi Päiväniemi, MD · Sub investigator
    • Evgenii Brushtein, MD · Sub investigator
    • Heikki Mäenpää, MD · Principal investigator
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Mar 2023 (actual). Primary completion is estimated for Dec 2031, 105 months after the start.

Of 72 interventional studies with no phase under Ankle Fractures, half reached primary completion within 45 months of starting (the median), counting those still running; a quarter within 23 and three quarters within 61. This study's planned 105 months is above that.

How these figures are worked out, and which studies are left out of them.

Registered
Sep 8, 2022
First posted
Sep 26, 2022
StartActual
Mar 7, 2023
Primary completionEst.
Dec 31, 2031
CompletionEst.
Apr 30, 2032
Last update
Mar 13, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Mar 13, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05555459
Lead sponsor
Inion Oy
Responsible party
Sponsor
First posted
Sep 26, 2022
Start date
Mar 7, 2023
Primary completion
Dec 31, 2031 (estimated)
Completion
Apr 30, 2032 (estimated)
Last update
Mar 13, 2026

Study contacts

Marika Manni, MD
Contact
marika.manni@inion.com
+358 50 366 9994
Kati Marttinen
Contact
kati.marttinen@inion.com
+358 40 841 6217
Mäenpää
principal investigator · Tampere University Hospital

Oversight

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

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