Development of "intelligent" external fixator systems

Project No. FF-FR 0118


completed 07/2009


Development of external fixators using robotics:
- Automatic reposition of fractures
- In vivo callus load measurements
- Detection of delayed healing
- Automatic callus distraction
- Telemedical data transmission
- Introduction into clinical application


- Integration of motors and sensors to the hexapod fixator
- Development of electronic components for central control unit and the distributed motor control units
- Development of software modules for tele-medical and knowledge based control
- Verification of the soft- and hardware modules
- Test of the complete fixator system
- Application on patients
- Optimization of the clinical procedure


The best possible treatment of fractures and especially malunions with deformities and defects is a classical task for the German Social Accident Insurance (DGUV).
Based on the hexapod external fixator, a universal external fixator with parallel kinematics already in clinical use, a robotic system was to be developed. A combination of force sensors, electric motors and state of the art microelectronics allows adaptation to the changing biomechanical situation during the treatment and supports the surgeon.
The "smart" external fixator system is to be used in common orthopedic and trauma treatments:
1. aftercare of fractures
2. primary reduction of fractures
3. secondary reduction of fractures
4. distraction osteogenesis
During the project the following systems were developed and built:
- Measuring fixator: Hexapod external fixator with force sensors in the distractors for the measurement of all loads and torques at the healing fracture with a PC-based evaluation.
- Motor fixator: Hexapod external fixator with electric motors for autonomous and PC-based movement.
- Control unit for the external fixator systems with power supply and embedded electronics: allows autonomous movement survey of mechanic loads
- PC-based control software the measuring and motordriven fixator systems with an additional telemedical module for internet-based data transmission between patient and surgeon.
The systems were designed for clinical application and were used to monitor the load characteristics during distraction osteogenesis as well as for motordriven fixator movements during deformity correction.

Last Update:

29 Mar 2010


Financed by:
  • Deutsche Gesetzliche Unfallversicherung e. V. (DGUV)
Research institution(s):
  • Berufsgenossenschaftliches Unfallkrankenhaus Hamburg

-cross sectoral-

Type of hazard:




Description, key words:

fixator extern, hexapod

Further information