RELIABILITY OF FRACTURE STIFFNESS AS A MEASUREMENT OF CLINICAL UNION AND VISCO-ELASTIC PROPERTIES OF CALLUS
MOORCROFT, Christopher and THOMAS, Peter and OGRODNIK, Peter (2008) RELIABILITY OF FRACTURE STIFFNESS AS A MEASUREMENT OF CLINICAL UNION AND VISCO-ELASTIC PROPERTIES OF CALLUS. Orthopaedic Proceedings, 90B (SUPP 3). p. 465. ISSN 2049-4416Full text not available from this repository.
Abstract or description
This is a clinically based study to assess the reliability of fracture stiffness as a measurement of clinical union and investigate other indicators which may aid the clinician to accurately determine when fracture fixation may be removed.
A fracture bending stiffness in the sagittal plane of 15Nm/deg. has been stated as a satisfactory endpoint at which an external fixator may be removed from diaphyseal fractures of the tibia. However using this as a measure to determine when to remove support in a study of 76 patients 4 continued to a malunion. Fracture callus properties were measured in clinic. The fixator was removed for the tests and a specially designed system was used to measure displacement and load. Fracture stiffness was measured in different planes and at various loading rates. Passive stressing of the leg was performed whilst fracture displacement was recorded. A constant load was applied for a longer period to assess creep properties.
Fracture stiffness was found to vary between different planes of measurement and on load rate. The visco-elastic characteristics of the callus changed with time. In early measurements, the callus absorbed a large proportion of energy when a load was applied. Later tests showed a progressive change with the callus absorbing less energy. This demonstrates that the properties of the callus changed with time, with the viscous element diminishing and the elastic element increasing. This sometimes occurred with no change in the measured fracture stiffness.
Further investigation is needed, focusing on the visco-elastic properties of callus, to develop a more reliable method of determining clinical union.
|Additional Information:||Accepted for Presentation at the South African Orthopaedic Association meeting, Durban, South Africa|
|Subjects:||A300 Clinical Medicine
B800 Medical Technology
H100 General Engineering
H300 Mechanical Engineering
H900 Others in Engineering
|Faculty:||Faculty of Computing, Engineering and Sciences > Engineering|
|Depositing User:||Peter OGRODNIK|
|Date Deposited:||12 Nov 2012 10:55|
|Last Modified:||12 Nov 2012 10:55|
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