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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Comparative Study
Study on accuracy and interobserver reliability of the assessment of odontoid fracture union using plain radiographs or CT scans.
In odontoid fracture research, outcome can be evaluated based on validated questionnaires, based on functional outcome in terms of atlantoaxial and total neck rotation, and based on the treatment-related union rate. Data on clinical and functional outcome are still sparse. In contrast, there is abundant information on union rates, although, frequently the rates differ widely. ⋯ A sensitivity of 77% and a specificity of 62% for the radiographs resemble a substantial lack of agreement if different observers evaluate odontoid union. Biplanar radiographs are judged not a reliable measure to detect odontoid fracture union or non-union. The union rates of odontoid fractures have to be revisited and CT scans as the endpoint anchor in outcome studies of treatment related union rates are recommended.
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Although both unconstrained and constrained core lumbar artificial disc designs are in clinical use, the effect of their design on the range of motion, center of rotations, and facet joint forces is not well understood. It is assumed that the constrained configuration causes a fixed center of rotation with high facet forces, while the unconstrained configuration leads to a moving center of rotation with lower loaded facets. The authors disagree with both assumptions and hypothesized that the two different designs do not lead to substantial differences in the results. ⋯ Results partially support our hypothesis and imply that different implant designs do not lead to strong differences in the range of motion and the location of center of rotations. In contrast, facet forces appeared to be strongly dependent on the implant design. However, due to the great variability in facet forces reported in the literature, together with our results, we could speculate that these forces may be more dependent on the individual spine geometry rather than a specific implant design.
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The incidence of adjacent segment problems after lumbar fusion has been found to vary, and risk factors for these problems have not been precisely verified, especially based on structural changes determined by magnetic resonance imaging. The purpose of this retrospective clinical study was to describe the incidence and clinical features of adjacent segment disease (ASD) after lumbar fusion and to determine its risk factors. We assessed the incidence of ASD in patients who underwent lumbar or lumbosacral fusions for degenerative conditions between August 1995 and March 2006 with at least a 1-year follow-up. ⋯ Facet degeneration was a significant risk factor (p < 0.01) on logistic regression analysis. The incidence of distal ASD was much lower than that of proximal ASD. Pre-existing facet degeneration may be associated with a high risk of adjacent segment problems following lumbar fusion procedures.
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The "off label" use of rhBMP-2 in the transforaminal lumbar interbody fusion (TLIF) procedure has become increasingly popular. Although several studies have demonstrated the successful use of rhBMP-2 for this indication, uncertainties remain regarding its safety and efficacy. The purpose of this study is to evaluate the clinical and radiographic outcomes of the single-level TLIF procedure using rhBMP-2. ⋯ Thirteen patients (27.1%) had one or more complications, including transient postoperative radiculitis (8/48), vertebral osteolysis (3/48), nonunion (2/48), and symptomatic ectopic bone formation (1/48). The use of rhBMP-2 in the TLIF procedure produces a high rate of fusion, symptomatic improvement and patient satisfaction. Although its use eliminates the risk of harvesting autograft, rhBMP-2 is associated with other complications that raise concern, including a high rate of postoperative radiculitis.