Variability in Flexion Extension Radiographs of the Lumbar Spine: A Comparison of Uncontrolled and Controlled Bending

Abstract

BackgroundWhile low back pain is one of the most prevalent, if not the most prevalent reasons for visits to physicians, a majority of patients with low back pain cannot be given a definitive diagnosis. While there have been substantial advances in imaging technologies over the past 30 years, relatively little has changed in the methodologies for evaluating functionality of the lumbar spine. The current standard of care for function assessment of the lumbar spine focuses on uncontrolled patient directed motion which results in increased inter-patient variability. Recent advancements in functional lumbar spine testing utilize controlled bending and computerized imaging evaluation.

The challenge of diagnosing lumbar segmental instability

“…End range vs mid-range controversy Numerous studies may support the hypothesis that the range of motion between vertebrae measured from conventional exion and extension X-rays is not as valuable as analysis of the pattern of motion between the endranges of the exion-extension cycle. (109,111,132,(151)(152)(153)(154)(155)(156)(157)(158)(159) These studies support that the greatest intervertebral rotation and translation can occur as the patient moves from exion to extension and not at the end-range of intervertebral motion. These studies also document that irregularities and discontinuities in intervertebral motion can occur during the exion-extension cycle that cannot be detected from a two-frame exion-extension study.…”

The Influence of Kinematic Constraints on Model Performance During Inverse Kinematics Analysis of the Thoracolumbar Spine

“…For each direction of static and dynamic motion [i.e., flexion–extension (FE), lateral bending (LB), and axial rotation (AR)], we estimated the proportion of each intervertebral level motion from previous work that provided values for FE, LB, and AR in the thoracic and lumbar spines ( Table 1 ). These studies evaluated segmental ranges of motion in vivo using a wide variety of techniques, including standard radiographs (Cheng et al, 2016 ), videofluoroscopy (Wong et al, 2006 ; Cheng et al, 2016 ), biplane radiography (Pearcy and Tibrewal, 1984 ; Shin et al, 2013 ), MRI (Fujii et al, 2007 ), CT scans (Fujimori et al, 2012 , 2014 ; Morita et al, 2014 ), a spinal mouse curvature measurement device (Mannion et al, 2004 ), motion analysis marker clusters attached to vertebral spinous processes via Kirshner wires (Rozumalski et al, 2008 ), and an electromagnetic motion analysis system (Willems et al, 1996 ). We also included reported physiological ROM from the works of White and Panjabi ( 1978 ) and Panjabi et al ( 1994 ).…”

“…However, direct measurement of individual vertebral movement is possible and can provide added information on spine biomechanics in health and disease. For instance, in vivo measurements of intervertebral motion can be obtained using various techniques such as biplane fluoroscopy (Lin et al, 2014 ; Wang et al, 2020 ), videofluoroscopy (Wong et al, 2006 ; Cheng et al, 2016 ), standard radiographs (Cheng et al, 2016 ), CT scans (Cheng et al, 2016 ), and MRI (Fujii et al, 2007 ). However, such methods are costly and highly invasive, making them impractical for widespread use for either clinical or research purposes.…”

An in vivo study exploring correlations between early-to-moderate disc degeneration and flexion mobility in the lumbar spine

“…A number of studies using quantitative fluoroscopy (QF) have investigated continuous multi-segmental lumbar intervertebral motion in detail, finding quantifiable differences in motion patterns between patients with back pain and controls [5][6][7][8][9]. One considered patients with and without DD, finding more out of plane motion in the latter [10], while another found substantial correlations between DD and the degree of unequal motion sharing (MSI) during recumbent passive flexion in patients, but not in controls [8] (Fig.…”