European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
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To investigate the relationship between the K-line tilt and classical cervical parameters such as the C2-C7 sagittal vertical axis (SVA), cervical lordosis, and the T1 slope in cervical sagittal alignment. We assessed whether the K-line tilt can be used as an excellent cervical parameter. ⋯ This study showed that the K-line tilt is also a useful parameter like the C2-C7 SVA and T1S-CL in cervical sagittal alignment. These slides can be retrieved under Electronic Supplementary Material.
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Radiation exposure is a necessary component of minimally invasive spine procedures to augment limited visualization of anatomy. The surgeon's exposure to ionizing radiation is not easily recognizable without a digital dosimeter-something few surgeons have access to. The aim of this study was to identify an easy alternative method that uses the available radiation dose data from the C-arm to accurately predict physician exposure. ⋯ Intra-operative radiation exposure to the patient, which is easily identifiable as a continuously updated fluoroscopic monitor, is a reliable predictor of radiation exposure to the surgeon during percutaneous screw placement in minimally invasive spinal fusion surgery and therefore can provide an estimate of exposure without the use of a dosimeter. With this, a surgeon can better understand the magnitude of their exposure on a case-by-case basis rather than on a quarterly basis, or more likely, not at all. These slides can be retrieved under Electronic Supplementary Material.
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Comparative Study
Pedicle screw anchorage of carbon fiber-reinforced PEEK screws under cyclic loading.
Pedicle screw loosening is a common and significant complication after posterior spinal instrumentation, particularly in osteoporosis. Radiolucent carbon fiber-reinforced polyetheretherketone (CF/PEEK) pedicle screws have been developed recently to overcome drawbacks of conventional metallic screws, such as metal-induced imaging artifacts and interference with postoperative radiotherapy. Beyond radiolucency, CF/PEEK may also be advantageous over standard titanium in terms of pedicle screw loosening due to its unique material properties. However, screw anchorage and loosening of CF/PEEK pedicle screws have not been evaluated yet. The aim of this biomechanical study therefore was to evaluate whether the use of this alternative nonmetallic pedicle screw material affects screw loosening. The hypotheses tested were that (1) nonmetallic CF/PEEK pedicle screws resist an equal or higher number of load cycles until loosening than standard titanium screws and that (2) PMMA cement augmentation further increases the number of load cycles until loosening of CF/PEEK screws. ⋯ Using nonmetallic CF/PEEK instead of standard titanium as pedicle screw material did not affect screw loosening in the chosen test setup, whereas cement augmentation enhanced screw anchorage of CF/PEEK screws. While comparable to titanium screws in terms of screw loosening, radiolucent CF/PEEK pedicle screws offer the significant advantage of not interfering with postoperative imaging and radiotherapy. These slides can be retrieved under Electronic Supplementary Material.
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Previous studies did not specifically assess the influence of proximal femoral angle (PFA) on sagittal balance in high-grade spondylolisthesis (HGS). In addition, the relationship between PFA and quality of life (QOL) remains unknown. This study determines if increased PFA is associated with decreased QOL and sagittal balance in lumbosacral HGS. ⋯ A PFA ≥ 10° is proposed as a criterion to define abnormal PFA. PFA was increased in HGS and increased along with deteriorating sagittal balance and QOL. PFA is a clinically relevant parameter of sagittal balance, and can be useful in the evaluation and management of patients with HGS.
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This study aims to investigate the clinical effect and complications of a novel technique named bridge crane for the treatment of the severe thoracic ossification of the ligamentum flavum (TOLF) with myelopathy. ⋯ The technique of bridge crane is feasible and may be relatively safe and effective for the treatment of severe TOLF with myelopathy. However, further studies with large-scale cases and control groups are required to reveal the generalizability and safety of the bridge crane technique in the future. These slides can be retrieved under Electronic Supplementary Material.