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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One of the main limitations of vertebroplasty is the excessive pressure required to inject a sufficient amount of cement into a vertebral body. Based on previous work that shows that approximately 95% of the injection pressure is required to deliver the cement through the cannula, we proposed a new cannula design with a larger internal diameter in the proximal section. The objective of this study is to determine whether the new cannula geometry significantly reduces the delivery pressure and eases cement injection during vertebroplasty. ⋯ Specifically, when the internal diameter of the proximal section was increased by a factor of two, which is clinically feasible, the delivery pressure dropped by about 63%. The redesigned cannula appears to have the potential to improve vertebroplasty. The key benefits are that (1) it eases cement injection, (2) it can be easily integrated into the existing procedure, and (3) it is cost-effective.
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The value of range of motion (ROM) as an indicator of impairment associated with spinal problems, and in monitoring changes in response to treatment, is a controversial issue. The aim of this study was to examine the interrelationship between subjective disability (Roland-Morris scores) and objectively measured impairment (ROM), both before and in response to spinal decompression surgery, in an older group of patients with herniated lumbar disc (DH). Seventy-six individuals took part in the study: 33 patients (mean age 57 years, SD 9 years) presenting with DH and for whom decompression surgery was planned, and 43 controls (mean age 57 years, SD 7 years), with no history of back pain requiring medical treatment. ⋯ The patients in the "poor" outcome group ("surgery didn't help"; 9%) had a significantly greater reduction in ROF(lumbar) post-surgery compared with the "good" outcome group ("surgery helped"; 91%) (p=0.04). In stepwise linear regression, the change in ROF(lumbar) was the only variable accounting for the change in self-rated disability pre-surgery to post-surgery (variables not included: pain intensity, psychological factors). The pivotal role of lumbar mobility in explaining disability emphasizes the importance of measuring lumbar and hip ranges of motion separately, as opposed to "global trunk motion." In the patient group examined, the determination of lumbar spinal mobility provides a valid, objective measure of function, that shows differences from normal matched controls, that correlates well with self-rated disability, and the changes in which correlate extremely well with subjective changes in disability following surgery.
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Comparative Study
Comparison of the biomechanical effects of posterior and anterior spine-stabilizing implants.
Posteriorly and anteriorly fixed implants for stabilizing unstable spines are available on the market. Differences in the biomechanical behavior of these implant types are not yet fully clear. They were investigated using three-dimensional nonlinear finite element models of the lumbar spine in an intact state, with an anteriorly fixed MACS-TL implant and with posteriorly fixed internal fixators. ⋯ In the period immediately after surgery, patients with osteoporotic vertebrae and who are treated with an internal spinal fixation device should therefore avoid excessive flexion. This study adds new information about the mechanical behavior of the lumbar spine after insertion of posterior and anterior spine-stabilizing implants. This information improves our biomechanical understanding of the spine.
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The objective of this study was to determine atlanto-axial bone morphometric measurements related to screw transarticular fixation technique. One hundred helical computerized tomography (helical CT) scans with volumetric acquisition, including the first and the second cervical vertebrae, were studied. The screw insertion axis according to the Magerl technique for C1-C2 transarticular fixation was the referential to select the correct oblique axial and oblique parasagittal planes obtained with multiplanar reconstruction (MPR) on helical CT. ⋯ In 6% of patients the potential risk was identified bilaterally. There is a great variation in the maximum and minimum values of the anatomic measurements. Therefore preoperative CT scans are very important to identify type II cases, such that the surgeon may preoperatively define the bony anatomy trough which the screws will pass.
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Low back pain (LBP) in children was considered for many years to be a rare condition revealing a serious disease, but in the last two decades, epidemiological studies have shown that the prevalence of nonspecific LBP in children is high. This study was aimed at analyzing the prevalence, severity, consequences and associated factors of LBP in children. A cross-sectional study was undertaken in two preparatory schools in the city of Monastir, Tunisia, in April 2002. ⋯ Two factors were associated with chronic LBP: dissatisfaction with school chair, OR=1.62 (95% CI, 1.46-3.32) and football playing, OR=3.07 (95% CI, 2.15-5.10). The prevalence of LBP among Tunisian schoolchildren and adolescents is high. This requires preventive measures and longitudinal studies, which are very important from the standpoint of public health.