The spine journal : official journal of the North American Spine Society
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Spinal intraoperative computer-assisted navigation (CAN) may guide pedicle screw placement. Computer-assisted navigation techniques have been reported to reduce pedicle screw breach rates across all spinal levels. However, definitions of screw breach vary widely across studies, if reported at all. The absolute quantitative error of spinal navigation systems is theoretically a more precise and generalizable metric of navigation accuracy. It has also been computed variably and reported in less than a quarter of clinical studies of CAN-guided pedicle screw accuracy. ⋯ Radiographic classifications of pedicle screw accuracy vary in sensitivity across spinal levels, as well as in inter-rater reliability. Correlation between clinical screw grade and absolute navigation accuracy is poor, as surgeons appear to compensate for navigation registration error. Future studies of navigation accuracy should report absolute translational and angular errors. Clinical screw grades based on postoperative imaging may be more reliable if performed in multiple by radiologist raters.
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The Örebro Musculoskeletal Pain Questionnaire (ÖMPQ) has good psychometric properties to predict return to work in patients with acute low back pain. Although it is used in patients with chronic back pain and nonworkers, there is no evidence on the factor structure of the ÖMPQ in these populations. This is deemed an important prerequisite for future prediction studies. ⋯ Factor structure of the ÖMPQ was not confirmed in working and nonworking patients with chronic back pain. Substantial adaptations should be made to obtain a factor structure with acceptable fit.
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Waddell et al. identified a set of eight non-organic signs in 1980. There has been controversy about their meaning, particularly with respect to their use as validity indicators. ⋯ Our results found significant evidence of an association between Waddell signs and somatic over-reporting. Elevated scores on the Waddell signs (particularly scores higher than 2 and 3) were associated with increased odds of exhibiting somatic over-reporting.