Date Published: May 16, 2012
Publisher: Hindawi Publishing Corporation
Author(s): Alan C. Breen, Deydre S. Teyhen, Fiona E. Mellor, Alexander C. Breen, Kris W. N. Wong, Adam Deitz.
Quantitative fluoroscopy (QF) is an emerging technology for measuring intervertebral motion patterns to investigate problem back pain and degenerative disc disease. This International Forum was a networking event of three research groups (UK, US, Hong Kong), over three days in San Francisco in August 2009. Its aim was to reach a consensus on how best to record, analyse, and communicate QF information for research and clinical purposes. The Forum recommended that images should be acquired during regular trunk motion that is controlled for velocity and range, in order to minimise externally imposed variability as well as to correlate intervertebral motion with trunk motion. This should be done in both the recumbent passive and weight bearing active patient configurations. The main recommended outputs from QF were the true ranges of intervertebral rotation and translation, neutral zone laxity and the consistency of shape of the motion patterns. The main clinical research priority should initially be to investigate the possibility of mechanical subgroups of patients with chronic, nonspecific low back pain by comparing their intervertebral motion patterns with those of matched healthy controls.
The need to be able to measure intervertebral motion in the diagnosis of problem back pain has been recognised for over a century. Attempts began with plain X-ray studies [1–5] and were followed by cineradiography [6–10], videofluoroscopy [11–16], roentgen stereophotogrammetry [17, 18], and magnetic resonance imaging [19, 20]. All have been found impractical for routine clinical use for a variety of reasons, ranging from poor image quality to low computing power, poor reliability and accuracy, laboriousness of multiple image registrations, X-ray dosage, invasiveness, cost and problems with sequential image acquisition. Until the emergence of quantitative fluoroscopy technologies, the standard approach to evaluating the mechanics of intervertebral linkages in vivo has remained a pair of plain radiographs taken at the end of bending range .
Three research teams led by Professor Alan Breen (AB) (UK), Dr Deidre Teyhen (DT) (US), and Dr Kris Wong (KW) (Hong Kong) met over three days to attempt to reach consensus on a proposal for optimal QF methodology for clinical and research studies. The Forum was also attended by representatives from the medical devices company Ortho Kinematics Inc., also of the US. After discussion on the rationale for quantitative fluoroscopy, the teams considered 4 subject areas: (1) choice of intervertebral motion measurement, (2) image sequence acquisition protocols, (3) image analysis methods, (4) future research priorities. Each team, in turn, described its methodology, followed by group discussions on a consensus in each area.
People with chronic, nonspecific low back pain are likely to be a very heterogeneous group. However, an objective diagnostic test that could help guide its management would be valuable for individual patients and society as a whole. These benefits would lie in being able to better predict who will benefit from spinal manipulation, exercises, and flexible stabilisation surgery. It may also predict who will return to work, who will need to leave their jobs, and who will become dependent on social support. Previous research has identified a number of weak to moderate predictors of these outcomes, but none have been able to objectively assess an intervertebral site that is suspected of being mechanically involved. In the future, QF technology may be used to determine which patients with chronic nonspecific back pain had a mechanical basis for it.