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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Case Reports Comparative Study
Finite element model of the Jefferson fracture: comparison with a cadaver model.
This study tries to explain the reason why the Jefferson fracture is a burst fracture, using two different biomechanical models: a finite element model (FEM) and a cadaver model used to determine strain distribution in C1 during axial static compressive loading. For the FEM model, a three-dimensional model of C1 was obtained from a 29-year-old healthy human, using axial CT scans with intervals of 1.0 mm. The mesh model was composed of 8200 four-noded isoparametric tetrahedrons and 37,400 solid elements. ⋯ The strain values obtained from the two experimental models showed similar trends. The FEM analysis revealed that maximum strain changes occurred where the maximum shear and von Mises stresses were concentrated. The changes in the C1 strain and stress values during static axial loading biomechanically prove that the Jefferson fracture is a burst fracture.
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The authors made several measurements in the lower lumbar vertebrae of patients with and without low back pain. Our objective was to determine the allometric relationships between different dimensions of the lumbar canal, the effects on these from degenerative disease, and differences between the symptomatic and asymptomatic populations. We compared 119 patients suffering from low back and sciatic pain and 39 subjects without lumbar symptoms as determined by computed tomography (CT). The following measurements were made: sagittal diameter of the canal, interpedicular distance, interarticular distance, and anteroposterior diameter of lateral recess and foramen. With respect to the patients with lumbar pain, the asymptomatic group proved to have wider foramina from L3 to L5 and wider sagittal diameters in S1. The patients with canal stenosis revealed lower figures for all diameters of the central canal, lateral recess of L4, and foramina of L4 and L5. Patients with lumbarization showed smaller diameters of the central canal. ⋯ There is an allometric relationship between the dimensions of the central canals. This relationship is less evident with lateral canals. The patients without lumbar symptoms had wider foramina and sagittal diameters in S1 than those with lumbar symptoms. Of these, patients who developed symptoms of canal stenosis demonstrated smaller diameters in central and lateral canals. Of the developmental anomalies, lumbarization proved to be associated with canal stenosis due to smaller diameters of the central canals.
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Randomized Controlled Trial Clinical Trial
The General Function Score: a useful tool for measurement of physical disability. Validity and reliability.
The General Function Score (GFS) is a disease-specific instrument consisting of nine items focusing on strict physical activities of daily living. It is intended as an alternative to the more complex scores of disability (such as the Oswestry Disability Index), serving as a complement to the quality of life instruments in the study of low back pain (LBP). It was developed from an original 17-item questionnaire, of which 11 of the items were tested for criterion validity in an observer-supervised performance test. ⋯ The GFS showed a high responsiveness to difference and change. The effect size was 0.82-0.96 in surgically treated disc herniation and 0.55-0.85 in spondylolisthesis. The GFS is a highly valid and reliable instrument with good responsiveness and feasibility, useful for evaluation of physical disability.
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Is the efficacy of the Cloward procedure overestimated? Technique of evaluation affects the outcome.
The purpose of the present study was to investigate the influence of the evaluation technique on the outcome of the Cloward procedure in cervical radiculopathy. The retrospective study included 94 consecutive patients operated on with anterior decompression and fusion with heterologous bone (Surgibone, Unilab). There were 56 men and 38 women, with a mean age of 48 years (range 27-78 years). ⋯ Only an excellent, but not a good, result as classified by the patient or an independent observer reflects a successful outcome. Neither of the variables studied seems independently sufficient for a balanced reflection of the outcome. The results suggest pain (VAS) as the primary outcome measurement, which, combined with the overall evaluation by the independent observer and work status, gives a multidimensional expression of the outcome.
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The aim of this report is to analyze the validity of allograft in anterior lumbar interbody fusion. Forty-three patients underwent anterior lumbar interbody fusion using allograft in the period between 1995 and 1998. All suffered from crippling chronic low back pain with or without sciatica. ⋯ However, radiological union could only be confirmed in 11 of the 12 levels in the three-level fusions. Allograft offers a better alternative to autograft for anterior lumbar interbody fusion. Donor site morbidity is avoided, hospital stay is shorter and fusion rates are satisfactory.