Apparatus for monitoring load bearing rehabilitation exercises of a transfemoral amputee fitted with an osseointegrated fixation: A proof-of-concept study

Frossard, Laurent; Gow, David Lee; Hagberg, Kerstin; Cairns, Nicola; Contoyannis, Bill; Gray, Steven; Brånemark, Richard; Pearcy, Mark

doi:10.1016/j.gaitpost.2009.10.010

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Volume 31, Issue 2 , Pages 223-228, February 2010

Apparatus for monitoring load bearing rehabilitation exercises of a transfemoral amputee fitted with an osseointegrated fixation: A proof-of-concept study

Laurent Frossard
- School of Engineering Systems, Queensland University of Technology, Brisbane, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
- Centre for Health Innovation and Solutions, The University of Queensland, Brisbane, Australia
- Corresponding author at: Centre for Health Innovation and Solutions, The University of Queensland, 4/49 Butterfield Street, Herston, QLD 4006, Australia. Tel.: +61 07 3251 5938; fax: +61 07 3251 5939.
David Lee Gow
- Caulfield General Medical Centre, Melbourne, Australia
Kerstin Hagberg
- Centre of Orthopaedic Osseointegration, Sahlgrenska University Hospital, Göteborg, Australia
Nicola Cairns
- School of Engineering Systems, Queensland University of Technology, Brisbane, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
Bill Contoyannis
- RehabTech, Monash Rehabilitation Technology Research Unit, Melbourne, Australia
Steven Gray
- Plastic Surgery Unit/Osseointegration OPRA Programme, The Alfred Hospital, Melbourne, Australia
Richard Brånemark
- Centre of Orthopaedic Osseointegration, Sahlgrenska University Hospital, Göteborg, Australia
Mark Pearcy
- School of Engineering Systems, Queensland University of Technology, Brisbane, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia

Received 30 March 2009; received in revised form 6 October 2009; accepted 20 October 2009. published online 19 November 2009.

Abstract

The purpose of this proof-of-concept study was to determine the relevance of direct measurements to monitor the load applied on the osseointegrated fixation of transfemoral amputees during static load bearing exercises. The objectives were (A) to introduce an apparatus using a three-dimensional load transducer, (B) to present a range of derived information relevant to clinicians, (C) to report on the outcomes of a pilot study and (D) to compare the measurements from the transducer with those from the current method using a weighing scale. One transfemoral amputee fitted with an osseointegrated implant was asked to apply 10kg, 20kg, 40kg and 80kg on the fixation, using self-monitoring with the weighing scale. The loading was directly measured with a portable kinetic system including a six-channel transducer, external interface circuitry and a laptop. As the load prescribed increased from 10kg to 80kg, the forces and moments applied on and around the antero-posterior axis increased by four-fold anteriorly and 14-fold medially, respectively. The forces and moments applied on and around the medio-lateral axis increased by nine-fold laterally and 16-fold from anterior to posterior, respectively. The long axis of the fixation was overloaded and underloaded in 17% and 83% of the trials, respectively, by up to ±10%. This proof-of-concept study presents an apparatus that can be used by clinicians facing the challenge of improving basic knowledge on osseointegration, for the design of equipment for load bearing exercises and for rehabilitation programs.