Affiliations: [a] School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW, Australia | [b] School of Mechanical Engineering, University of Birmingham, Birmingham, UK | [c] Department of Radiology, Woodend Hospital, Aberdeen, UK | [d] Department of Orthopaedics, Woodend Hospital, Aberdeen, UK | [e] Orthopaedics and Trauma, Queen Elizabeth Hospital, Gateshead, UK
Correspondence:
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Corresponding author: Steven Harvey, School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong NSW 2522, Australia. Tel.: +61 2 4253 4100; Fax: +61 2 4253 4112; E-mail:sharvey@uow.edu.au
Abstract: BACKGROUND:
Static radiographic techniques are unable to capture the wealth of kinematic
information available from lumbar spine sagittal plane motion. OBJECTIVE:
Demonstration of a viable non-invasive technique for acquiring and
quantifying intervertebral motion of the lumbar spine in the sagittal plane. METHODS:
Videofluoroscopic footage of sagittal plane lumbar spine flexion-extension
in seven symptomatic volunteers (mean age = 48 yrs) and one asymptomatic
volunteer (age = 54 yrs) was recorded. Vertebral bodies were digitised using
customised software employing a novel vertebral digitisation scheme that was
minimally affected by out-of-plane motion. RESULTS:
Measurement errors in intervertebral rotation (± 1°) and
intervertebral displacement (± 0.5 mm) compare favourably with the work
of others. Some subjects presenting with an identical condition (disc
prolapse) exhibited a similar column vertebral flexion-extension relative to
S1 (L3: max. 5.9°, min. 5.6°), while in others (degenerative disc
disease) there was paradoxically a significant variation in this measurement
(L3: max. 28.1°, min. 0.7°). CONCLUSIONS:
By means of a novel vertebral digitisation scheme and customised
digitisation/analysis software, sagittal plane intervertebral motion data
of the lumbar spine data has been successfully extracted from
videofluoroscopic image sequences. Whilst the intervertebral motion
signatures of subjects in this study differed significantly, the available
sample size precluded the inference of any clinical trends.
