Skip to main content
OpenTrials
Completed

NCT Number: NCT02094209

Focused Registry SmartFix

20 patients having received an AO large external fixator at the tibia will be equipped with a data logger device (AO Fracture Monitor) attached post-operation to a connection rod of the external fixator. The device continuously measures deformation of the fixator frame due to weight bearing for up to 6 months by means of a strain gauge. Several parameters are calculated from the recorded change in the strain signal and are stored at a regular interval.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Fracture of Shaft of Tibia Fractures, Bone Leg Injuries Tibial Fractures Wounds and Injuries

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Berufsgenossenschaftliche Unfallklinik

Tübingen, Baden-Wurttemberg, 72076, Germany

About this study

Maturation of fracture callus leads to unloading of the fracture fixation hardware due to an increased load-share of the repair tissue. A novel data logger device (AO Fracture Monitor) continuously measures the decline in fixation hardware deflection under physiological loading as indirect indicator for the healing progress. Parameters obtained from the data logger device carry potential to significantly improve the assessment of fracture healing in the future. Meaningful interpretation of measurements requires a set of clinical reference data.

20 patients having received an AO large external fixator at the tibia will be equipped with a data logger device (AO Fracture Monitor) attached post-operation to a connection rod of the external fixator. The device continuously measures deformation of the fixator frame due to weight bearing for up to 4 months by means of a strain gauge. Several parameters are calculated from the recorded change in the strain signal and are stored at a regular interval. Data is collected from the AO Fracture Monitor at follow-up visits of the patient by wireless data transfer. Together with additional variables such as treatment details, fracture healing and pain reported by the patient, the collected data is used to build up a database. Data from the AO Fracture Monitor will be correlated with patient data to investigate the relevance and reliability of the data derived from the AO Fracture Monitor.

In this phase, the study does not imply changes on the operational treatment, nor does it allow for therapeutic consequences based on the derived data.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 18 years and older
  • Diagnosis of Femoral or tibial fracture (AO 41-43)
  • External fracture fixation with AO large external fixator
  • Capable of at least partial weight-bearing
  • Informed consent obtained, i.e.:
  • Ability to understand the content of the patient information/Informed Consent Form (ICF)
  • Willingness and ability to participate in the Focused Registry according to the Registry Plan (RP)
  • Signed and dated Ethics Committee (EC) approved written informed consent

Exclusion criteria

Preoperative exclusion criteria:

  • External fixation as temporary stabilization
  • Joint-bridging external fixation
  • Any not medically managed severe systemic disease
  • Recent history of substance abuse (i.e. recreational drugs, alcohol) that would preclude reliable assessment
  • Pregnancy or nursing mother
  • Emergency patient
  • Prisoner
  • Participation in any other medical device or medicinal product study within the previous month that could influence the results of the present study

Treatment and study plan

SmartFix

Device

AO Fracture Monitor attached postoperatively to a connection rod of the external fixator. The device continuously measures deformation of the fixator frame due to weight bearing for up to 4 months by means of a strain gauge.

Primary outcomes

  1. Changes in Parameters derived from the AO Fracture Monitor during bone healing

    Time frame: Discharge, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months

    AO Fracture Monitor:

    • Mean deformation amplitude per 6 hours
    • Mean deformation rate
    • Number of load-cycles
    • Histogram of patient activity (load intensity distribution)

Secondary outcomes

  1. Change in Pain during bone healing

    Time frame: Preoperative, Discharge, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months (after surgery)

    Pain measured with visual analog scale (VAS)

  2. Change in weight-bearing during bone healing

    Time frame: Discharge, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months (after surgery)

    Documentation of allowed weight-bearing

  3. Repeated reference deformation at a load of 20 / 30 kg

    Time frame: Discharge, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months (after surgery)

    Two reference deformation values are measured under a load 20 kg and 30 kg respectively. The patient steps with his injured leg on a bathroom scale and loads it first with the reference load of 20 kg. The investigator then starts the measurement of the corresponding deformation value. After an acoustic signal indicates the end of the measurement, the procedure is repeated with a reference load of 30 kg. If the patient is not able to put the required load on his leg (e.g. due to pain), the reference value should be measured at a lower load with a note of the actually applied load in the patient record.

  4. Patient information

    Time frame: Up to 4 weeks before surgery

    • Patient demographics
    • Comorbidities

  5. Treatment information

    Time frame: Discharge

    • Fracture classification according to AO and Gustilo
    • Reason for external fixator treatment
    • Previous treatment related to current injury, if any
    • Fixator configuration

  6. Development of the radiological healing assessment: RUST system

    Time frame: Discharge, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months (after surgery)

    The Radiographic Union Score for Tibial fractures (RUST score) is a reliable score to assess the healing of tibial fractures. Each of the four cortices (anterior, posterior, medial and lateral) is given a value from 1 to 3, depending on the presence of a callus and the visibility of the fracture line. The sum of the individual cortical scores results in a RUST value between 4 (definitely not healed) to 12 (definitely healed).

    To investigate, whether patient activity as measured by the AO Fracture Monitor correlate with the radiological assessed course of healing.

Sponsors and collaborators

Lead sponsor

AO Clinical Investigation and Publishing Documentation

Other

Registry information

Official study title

Clinical Data Collection With a Novel Biofeedback Technology for Continuous Monitoring of Bone Healing

Acronym: FRSmartFix

Important dates

Study start
2015
Primary completion
2017
Study completion
2017
First posted
Mar 21, 2014
Registry last updated
Aug 12, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.