Static load bearing exercises of individuals with transfemoral amputation fitted with an osseointegrated implant: Loading compliance.
BACKGROUND
Load-bearing exercises are performed by transfemoral amputees fitted with an osseointegrated implant to facilitate bone remodelling.


OBJECTIVE
This study presents the loading compliance comparing loads prescribed and applied on the three axes of the implant during static load-bearing exercises with a specific emphasis on axial and vectorial comparisons.


METHODS
Cohort study.


METHODS
A total of 11 fully rehabilitated unilateral transfemoral amputees fitted with an osseointegrated implant performed five trials in four loading conditions using a static standing frame. The load prescribed was monitored using a vertical single-axis strain gauge connected to an electronic display. The tri-axial forces applied on the implant were measured directly with an instrumented pylon including a six-channel transducer. The analysis included 'axial' and 'vectorial' comparisons corresponding to the difference between the force applied on the long axis of the implant and the load prescribed as well as the resultant of the three components of the load applied and the load prescribed, respectively.


RESULTS
The results demonstrated that axial and vectorial differences were significant in all conditions ( p < 0.05), except for the vectorial difference for the 40 kg condition ( p = 0.182).


CONCLUSIONS
The significant lack of axial compliance led to systematic underloading of the long axis of the implant. Clinical relevance This study contributes to a better understanding of the load applied on an osseointegrated implant during the static load-bearing exercises that could contribute to improve the design of apparatus to monitor loading exercises as well as clinical guidelines for the loading progression during rehabilitation.
1 Department of Physical and Rehabilitation Medicine, University Hospital, Ghent, Belgium.
Sofie
S
Vertriest
2 Department of Public Health, Unit of Medical Informatics and Statistics, Ghent University, Ghent, Belgium.
Pascal
P
Coorevits
3 Department of Prosthetics and Orthotics, Sahlgrenska University Hospital, Gothenburg, Sweden.|4 Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Kerstin
K
Hagberg
4 Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|5 Centre of Orthopaedic Osseointegration, Sahlgrenska University Hospital, Gothenburg, Sweden.
Rickard
R
Brånemark
3 Department of Prosthetics and Orthotics, Sahlgrenska University Hospital, Gothenburg, Sweden.|4 Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Eva Elisabet
EE
Häggström
1 Department of Physical and Rehabilitation Medicine, University Hospital, Ghent, Belgium.|6 Department of Physical Medicine and Orthopaedic Surgery, University, Ghent, Belgium.
Guy
G
Vanderstraeten
7 Queensland University of Technology, Brisbane, QLD, Australia.|8 University of the Sunshine Coast, Maroochydore, QLD, Australia.
Laurent Alain
LA
Frossard
D000328:Adult; D000671:Amputation, Surgical / Q000534:rehabilitation*; D001186:Artificial Limbs; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D016474:Weight-Bearing / Q000502:physiology*
Amputation; bone-anchored prostheses; compliance; implant; lower extremity; osseointegration; prosthesis; rehabilitation; transducer; weight bearing