Performance and Safety Follow-up of Bioabsorbable Headless Inion CompressOnTM Screws in the Fixation of Bone Fractures in Ankle, Knee and Elbow of Pediatric and Adolescent Patients

The study in question is a post market clinical follow up (PMCF) study to follow up the safety and performance of bioabsorbable headless compression screw Inion CompressOn in fracture fixation of the ankle, knee and elbow of pediatric and adolescent patients. The study aims to recruit 80 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 Lighthouse Hospital at Turku University Hospital (TYKS) in Finland. The main focus of the study in terms of performance is to follow up 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.

Study Overview

• Status: Recruiting
• Conditions: Ankle Fractures; Elbow Fractures; Knee Fractures
• Intervention / Treatment: Device: Fracture fixation operation

Detailed Description

The study in question is a post market clinical follow-up study to follow-up the safety and performance of the bioabsorbable headless Inion CompressOn Screw in fracture fixation operations of the ankle, knee and elbow of pediatric and adolescent patients. The main focus of the study in terms of performance is to follow-up 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-hydroxyacids 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 four years.

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 is used for the same indications. Inion CompressOn Screw has new design features such as headless design, and threading which allows compression to the fracture line. Also new sizes have been introduced.

The study recruits 80 pediatric/adolescent 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 (4-8 weeks),
4. post-operative follow-up 2 (3 months after operation +/- 3 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 Turku University Hospital (TYKS) in Finland.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Kati Marttinen; Phone Number: +358 40 841 6217; Email: kati.marttinen@inion.com
• Study Contact Backup: Name: Marika Manni, MD; Phone Number: +358503669994; Email: marika.manni@inion.com

Study Locations

• Finland
  • Turku, Finland, 20520
    • Recruiting
    • Turku University Hospital/Lighthouse hospital
    • Sub-Investigator: Johanna Syvänen, MD
    • Contact: Olli Pajulo, MD; Phone Number: +358 2 313 0000; Email: olli.pajulo@varha.fi
    • Principal Investigator: Olli Pajulo, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Informed consent signed by parents or legal guardians, and assent from the child if of appropriate age and cognitive ability < 18 years 3. Suitable and in need for an operation indicated for subject device 4. Ability to give adequate input for the PROM questionnaires 5. Willingness and ability to comply with rehabilitation instructions. 6. Availability for follow-up visits.

Exclusion Criteria:

1. Active infection
2. Patient conditions including limited blood supply (e.g. patients with severe circulatory disorder of the lower or upper 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. Patients with known allergy to the implant constituents or its degradation products.
6. Spinal and craniomaxillofacial indications.
7. High-load bearing indications (e.g., diaphyseal fractures of long bones) unless used in conjunction with traditional rigid fixation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CompressOn group; Participants undergo a surgical fracture fixation procedure using the bioabsorbable Inion CompressOn Screw according to the device instructions for use.	Device: Fracture fixation operation; Fracture fixation operation in using bioabsorbable headless Inion CompressOn Screw/s according to instructions for use

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Occurrence of revision surgeries	Assessment of occurrence of revision surgeries related to study device	During 4-year follow-up
Bone healing (ossification) of the fracture line(s)	X-ray evaluation of bone healing (ossification) of the fracture line(s)	Change from operation to 4 years
Occurrence of device-related adverse events	Assessment of occurrence of adverse events (AE), that are or might be related to the study device such as non-union of bone, fixation failure, mechanical irritation and tissue reactions related to implant bioabsorption	During 4-year follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subjective functionality of the operated limb (Visual Analogue Scale, VAS)	Evaluation of subjective pain of the operated area during follow-up. 10-cm (100-mm) horizontal line used to measure pain intensity, ranging from "no pain" (0) to "worst imaginable pain" (100 mm)	Change from baseline to 4 years
Subjective functionality of the operated area (Lower Extremity Functional Scale, LEFS/Upper Extremity Functional Index, UEFI)	Evaluation of subjective functionality of the operated area follow-up. UEFI: The scores given to the 20 questions are added to give a highest possible score of 80. The lowest possible score is 0. A lower score indicates that the person is reporting increased difficulty with the activities as a result of their upper limb condition. LEFS: Contains 20 questions about a person's ability to perform everyday tasks. The maximum score is 80. The lower the score the greater the disability.	Change from baseline to 4 years

Collaborators and Investigators

• Sponsor: Inion Oy
• Investigators: Principal Investigator: Olli Pajulo, MD, Turku University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): May 29, 2026
• Primary Completion (Estimated): February 1, 2032
• Study Completion (Estimated): December 1, 2032

Study Registration Dates

• First Submitted: March 11, 2026
• First Submitted That Met QC Criteria: March 11, 2026
• First Posted (Actual): March 16, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: ankle fracture; elbow fracture; resorbable; bioabsorbable; fracture fixation; knee fracture
• Additional Relevant MeSH Terms: Elbow Injuries; Wounds and Injuries; Leg Injuries; Fractures, Bone; Arm Injuries; Knee Injuries; Ankle Injuries; Elbow Fractures; Knee Fractures; Ankle Fractures
• Other Study ID Numbers: CompressOn2-2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No