Experimental study of ligamentotaxis maneuvers sequencing in vertebral canal decompression

A descompressão do canal vertebral, para aliviar as estruturas nervosas, pode ser realizada por meio da ligamentotaxia. O objetivo foi analisar a influência da seqüência de realização da ligamentotaxia sobre a descompressão do canal vertebral. Foram utilizados segmentos de vértebras de suínos (Landrace). Um equipamento especialmente desenvolvido foi utilizado para produção de fratura do tipo explosão. Após a tomografia computadorizada, 10 espécimes que melhores apresentavam fraturas do tipo explosão foram fixados com fixador interno (Synthes). Foram formados dois grupos. No primeiro (n=5) foi realizada a lordose e depois a distração. Posteriormente, foram submetidos à nova compressão por meio de morsa até o retorno da fratura à posição inicial, a seguir foram novamente submetidos à distração e lordose. No segundo grupo (n=5) foi realizada a distração e depois a lordose. Após cada manobra era realizado o exame tomográfico para medir o diâmetro do canal vertebral. Os deslocamentos dos fragmentos dos corpos vertebrais fraturados foram mensurados e comparados utilizando t de Student (p<0,05). Comparando os deslocamentos entre os grupos, não foram observadas diferenças estatísticas (p<0,06). Esse resultado é próximo ao nível de significância adotado, sugerindo uma forte tendência que demonstra a eficácia superior da manobra iniciada pela realização da lordose.Vertebral canal decompression, intended to provide relief to nervous structures, may be performed by means of legamentotaxis. The objective of this study was to assess the influence of the ligamentotaxis sequence on vertebral canal decompression. Vertebral segments of Landrace swine specimens were used. A device especially developed for producing a burst-type fracture was employed. Subsequently to the computerized tomography scan, 10 specimens that best showed a burst-type fracture were fixated with internal fixator (Synthes). Two groups were formed. On the first group (n=5), lordosis followed by distraction were performed. Then, they were submitted to distraction and lordosis. On the second group (n=5), distraction was provided first, and then lordosis was performed. After each maneuver, vertebral canal was measured by tomography scan. Fractured vertebral body fragments were measured and compared using the Student's t test (p<0,05). By comparing dislocations between groups, no statistical differences were found (p<0,06). This result is close to the significance level adopted, suggesting a strong trend towards a better effectiveness of the maneuver started with lordosis

What should an ideal spinal injury classification system consist of? A methodological review and conceptual proposal for future classifications

Since Böhler published the first categorization of spinal injuries based on plain radiographic examinations in 1929, numerous classifications have been proposed. Despite all these efforts, however, only a few have been tested for reliability and validity. This methodological, conceptual review summarizes that a spinal injury classification system should be clinically relevant, reliable and accurate. The clinical relevance of a classification is directly related to its content validity. The ideal content of a spinal injury classification should only include injury characteristics of the vertebral column, is primarily based on the increasingly routinely performed CT imaging, and is clearly distinctive from severity scales and treatment algorithms. Clearly defined observation and conversion criteria are crucial determinants of classification systems’ reliability and accuracy. Ideally, two principle spinal injury characteristics should be easy to discern on diagnostic images: the specific location and morphology of the injured spinal structure. Given the current evidence and diagnostic imaging technology, descriptions of the mechanisms of injury and ligamentous injury should not be included in a spinal injury classification. The presence of concomitant neurologic deficits can be integrated in a spinal injury severity scale, which in turn can be considered in a spinal injury treatment algorithm. Ideally, a validation pathway of a spinal injury classification system should be completed prior to its clinical and scientific implementation. This review provides a methodological concept which might be considered prior to the synthesis of new or modified spinal injury classifications

Letter to the Editor: Is there a difference between narrowing of the spinal canal and neurological deficits comparing Denis and Magerl classifications?

We have read with great interest the retrospective study by Caffaro and Avanzi1 evaluating the relation between narrowing of the spinal canal and neurological deficits in patients with burst-type fractures of the spine. The authors are to be commended for obtaining detailed neurological and radiological data in a large cohort of 227 patients. The authors conclude: “The percentage of narrowing of the spinal canal proved to be a pre-disposing factor for the severity of the neurological status in thoracolumbar and lumbar burst-type fractures according to the classifications of Denis and Magerl.” Although this conclusion is mainly in accordance with previous findings, we would like to comment on the methodological approach applied in the current study

Effectiveness of postural and instrumental reduction in the treatment of thoracolumbar vertebra fracture

We compared the effectiveness of postural reduction and instrumental reduction in the treatment of thoracolumbar and lumbar vertebra fracture in 40 patients. Under general anaesthesia, postural reduction in a stretching prone position was first performed. Instrumental reduction and fixation were then conducted. Radiographs were made after each reduction. Comparisons between the two films and the fracture films were made based on the changes in prevertebral height of both the fractured vertebra and the adjacent superior and inferior intervertebral spaces. It was found that the recovery of the prevertebral height in postural and instrumental reductions was basically identical. The recovery of the prevertebral height in the intervertebral spaces was more significant in instrumental reduction. Both reductions were ineffective in patients whose compression of the diseased vertebra was more than two-thirds of the normal. In cases of lower lumbar vertebra fractures, the effect of both reductions was unsatisfactory. Our findings indicated that the effectiveness of the reduction of vertebra fracture depends on the quantitative change of the spongy bone of the injured vertebra. Instrumental reduction only exerts an indirect tension. Postural reduction is effective in reducing thoracolumbar vertebral fracture, while instrumental reduction exerts only a relatively weak effect but it is particularly useful to maintain the result of postural reduction

Is posterior fixation alone effective to prevent the late kyphosis after T-L fracture?

INTRODUCTION: The posterior transpedicular fixation technique is a standard procedure for stabilizing the injured thoracolumbar spine but the long-term results of this approach are controversial. Clear guidelines are missing and the literature shows complete disagreement regarding indications, approaches, surgical techniques, and type of fixation. MATERIAL AND METHOD: The objective of this study is to investigate if the surgical treatment by posterior approach alone is always enough to prevent the late kyphotic deformity through the retrospective analysis of 219 patients affected with a thoracolumbar injury. Follow-up examinations included radiographic measurements of the sagittal index (SI) and the sagittal plane kyphosis (SPK). RESULT: Results show that, at the follow-up, the SI remains almost stable after the surgical correction, while the SPK (which describes the eventual injury of the affected intervertebral disc) decreases indicating a progressive regional kyphotic deformity. Thus, in some cases posterior fixation alone is not sufficient for long-term spinal stabilization and often can be not effective to prevent the late kyphotic deformity

Mid-term results of PLIF/TLIF in trauma

Treatment of thoracolumbar fractures is still controversial. Several treatment options are reported to yield satisfactory results. There is no evidence indicating superiority of any treatment option. We have already presented radiological results of the use of PLIF/TLIF in trauma, which showed satisfactory results concerning intervertebral fusion and acceptable loss of correction. We examined 50 patients regarding loss of correction after implant removal and clinical outcome using a validated visual analogue score. The average time of follow-up (FU) was 35 months. We observed a total loss of correction of 4°. The pre-injury mean VAS score was 92. At FU, there was an average reduction of 17.2 points. Owing to the presented results, we suggest this method as an alternative to combined procedures