Las diferencias antropométricas entre sexos de la columna lumbar, medidas por dxa, no afectan a todas las vértebras en forma uniforme: probable implicancia en la incidencia de fracturas / Gender anthropometric differences of the lumbar spine, measured by dxa, do not involve all vertebrae uniformly: probable implication in the incidence of fractures

Las fracturas vertebrales osteoporóticas son más frecuentes en la mujer. El segmento toracolumbar es el preferentemente comprometido, en especial las vértebras D11 a L2, mientras que L4 contribuye en una proporción mínima a este evento. El objetivo del presente estudio fue investigar si el menor tamaño de las vértebras lumbares en las mujeres con respecto a los varones, involucra a todas las vértebras por igual o solamente a las que con más frecuencia se fracturan. Se analizaron en forma aleatoria las densitometrías óseas (DXA) de la región lumbar de 48 mujeres y 45 varones adultos. Se consideró el ancho del segmento L1-L2 (S L1-L2) y de L4 como un subrogado del área de sus cuerpos vertebrales. Resultados: ancho S L1-L2 Hombres: 4,32 ± 0,33 cm; Mujeres: 3,78 ± 0,23 cm, p < 0,001. Ancho L4 Hombres: 5 ± 0,37 cm; Mujeres: 4,66 ± 0,38 cm, p < 0,001. Diferencia de L4 menos S L1-L2: Hombres: 0,69 ± 0,25 cm, Mujeres: 0,88 ± 0,27 cm p < 0,001. Ancho relativo (S L1-L2/L4): Hombres: 0,86 ± 0,04, Mujeres 0,81 ± 0,04 p <0,001. Conclusiones: en el presente estudio observamos, en consonancia con lo ya conocido, que las mujeres tienen en promedio vértebras más pequeñas que los hombres. La diferencia de tamaño no es uniforme en las vértebras lumbares, siendo el segmento L1-L2 particularmente menor comparado con L4. Estas diferencias estructurales entre mujeres y hombres deben ser consideradas para explicar, dentro del contexto multifactorial de las fracturas vertebrales, la mayor incidencia de éstas en el sexo femenino, en particular de L1 y L2. (AU)

Vertebral fractures occur most frequently in thoracolumbar region, especially D11- L2, while L4 contributes minimally to this event. That cannot be explained by differences in loading during daily activities or bone quality between vertebrae. Differences exist in vertebral size. The aim of the study was to evaluate in female lumbar spines if vertebrae which most frequently fracture are smaller than L4. We analyzed BMD (DXA) of 48 women (W) and 45 men (M). The width of the segment L1-L2 (S L1-L2) and of L4 was considered a surrogate of vertebral bodies Results: Width S L1-L2: Men: 4,32 ± 0,33 cm; Women: 3,78 ± 0,23 cm, p < 0,001. Width L4: Men: 5 ± 0.37; Women: 4,66 ± 0,38 cm, p < 0,001. Difference between L4 and S L1-L2: Men: 0,69 ± 0,25cm, Women: 0,88 ± 0,27 cm p < 0,001. Relative width (S L1-L2/L4) Men: 0,86 ± 0,04 Women: 0,81 ± 0,04 p <0,001. Conclusions: the study shows, as already known, that women have smaller vertebrae than men. The differences are not uniform in the lumbar spine, L1 and L2 being particularly smaller compared to L4. These structural differences between women and men should be considered to explain, within the multifactorial context of vertebral fractures, the greater incidence in female, particularly L1 and L2. (AU)

Comparison of short-segment monoaxial and polyaxial pedicle screw fixation combined with intermediate screws in traumatic thoracolumbar fractures: a finite element study and clinical radiographic review

OBJECTIVES: No studies have compared monoaxial and polyaxial pedicle screws with regard to the von Mises stress of the instrumentation, intradiscal pressures of the adjacent segment and adjacent segment degeneration. METHODS: Short-segment monoaxial/polyaxial pedicle screw fixation techniques were compared using finite element methods, and the redistributed T11-L1 segment range of motion, largest maximal von Mises stress of the instrumentation, and intradiscal pressures of the adjacent segment under displacement loading were evaluated. Radiographic results of 230 patients with traumatic thoracolumbar fractures treated with these fixations were reviewed, and the sagittal Cobb's angle, vertebral body angle, anterior vertebral body height of the fractured vertebrae and adjacent segment degeneration were calculated and evaluated. RESULTS: The largest maximal values of the von Mises stress were 376.8 MPa for the pedicle screws in the short-segment monoaxial pedicle screw fixation model and 439.9 MPa for the rods in the intermediate monoaxial pedicle screw fixation model. The maximal intradiscal pressures of the upper adjacent segments were all greater than those of the lower adjacent segments. The maximal intradiscal pressures of the monoaxial pedicle screw fixation model were larger than those in the corresponding segments of the normal model. The radiographic results at the final follow-up evaluation showed that the mean loss of correction of the sagittal Cobb's angle, vertebral body angle and anterior vertebral body height were smallest in the intermediate monoaxial pedicle screw fixation group. Adjacent segment degeneration was less likely to be observed in the intermediate polyaxial pedicle screw fixation group but more likely to be observed in the intermediate monoaxial pedicle screw fixation group. CONCLUSION: Smaller von Mises stress in the pedicle screws and lower intradiscal pressure in the adjacent segment were observed in the polyaxial screw model than in the monoaxial pedicle screw fixation spine models. Fracture-level fixation could significantly correct kyphosis and reduce correction loss, and adjacent segment degeneration was less likely to be observed in the intermediate polyaxial pedicle screw fixation group.

Asymptomatic vertebral fractures in patients with low bone mineral density / Fraturas vertebrais assintomáticas em indivíduos com baixa massa óssea

Summary Objective: Vertebral fracture assessment (VFA) is a test technique that can be used to detect asymptomatic vertebral fractures (AVF). It uses dual energy X-ray bsorptiometry (DXA) and can be performed concurrently with bone densitometry. This study aims to assess the prevalence of AVF in patients with low bone mass. Methods: Cross-sectional study including 135 individuals with low bone mineral density (BMD) with a T-score < -2.0 standard deviation (SD) in a densitometry clinic located in the city of Blumenau (state of Santa Catarina). Anthropometric, clinical and lifestyle variables were obtained from history-taking and physical examination. Densitometric variables were obtained by bone mineral densitometry and VFA (Explorer, Hollogic®). Vertebral fractures were classified according to the Genant criteria. Student's t, chi-square and logistic regression were performed for statistical analysis. Results: AVFs occurred in 24.4% of the subjects. They were older compared to those without AVF (65±9.25 versus 60.1±8.66; p=0.005), and had a history of lowimpact fractures (38.24% versus 19.8%; OR 2.5; p=0.03). Half of the patients that reported steroid therapy had AVFs, compared to one fifth of those who did not use steroids (50% versus 21.49%; OR 3.6; p=0.01). Conclusion: Asymptomatic vertebral fractures were present in approximately one fourth of patients. The risk factors associated were history of low-impact fracture, use of steroids and age > 61 years.

Resumo Objetivos: vertebral fracture assessment (VFA) é uma técnica de exame que pode ser aplicada na detecção de fraturas vertebrais assintomáticas (FVA). Utiliza absorciometria de raios-X de dupla energia (DXA) e pode ser realizada concomitantemente ao exame de densitometria óssea. Este estudo visa a avaliar a prevalência de FVA em indivíduos com baixa massa óssea. Métodos: estudo transversal realizado em 135 indivíduos, com baixa densidade mineral óssea (DMO), com T-score < -2,0 desvio padrão (DP), em uma clínica de densitometria de Blumenau (SC). As variáveis antropométricas, clínicas e referentes ao estilo de vida foram obtidas por anamnese e exame clínico; as variáveis densitométricas foram obtidas por DMO e VFA (aparelho modelo Explorer, marca Hollogic®). As fraturas vertebrais foram classificadas de acordo com os critérios de Genant. Os testes estatísticos foram t de student, qui-quadrado e regressão logística. Resultados: FVA ocorreram em 24,4% dos indivíduos. A idade desses indivíduos foi superior à dos indivíduos sem FVA (65±9,25 vs. 60,1±8,66; p=0,005), assim como o antecedente de fratura por baixo impacto (38,24% vs.19,8%; OR 2,5; p=0,03). A metade dos indivíduos que relataram corticoterapia possuíam FVA, contrastando com um quinto dos indivíduos sem corticoterapia (50% vs. 21,49%; OR 3,6; p=0,01). Conclusão: fraturas vertebrais assintomáticas estiveram presentes em aproximadamente um quarto dos pacientes. Os fatores de risco associados foram história de fratura por baixo impacto, corticoterapia e idade > 61 anos.

More than 5-Year Follow-up Results of Two-Level and Three-Level Posterior Fixations of Thoracolumbar Burst Fractures with Load-Sharing Scores of Seven and Eight Points

BACKGROUND: The development of pedicle screw-based posterior spinal instrumentation is recognized as one of the major surgical treatment methods for thoracolumbar burst fractures. However, the appropriate level in posterior segment instrumentation is still a point of debate. To assesses the long-term results of two-level and three-level posterior fixations of thoracolumbar burst fractures that have load-sharing scores of 7 and 8 points. METHODS: From January 1998 to May 2009, we retrospectively analyzed clinical and radiologic outcomes of 45 patients with thoracolumbar burst fractures of 7 and 8 points in load-sharing classification who were operated on using two-level posterior fixation (one segment above and one segment below: 28 patients, group I) or three-level posterior fixation (two segments above and one segment below: 17 patients, group II). Clinical results included the grade of the fracture using the Frankel classification, and the visual analog score was used to evaluate pain before surgery, immediately after surgery, and during follow-up period. We also evaluated pain and work status at the final follow-up using the Denis pain scale. RESULTS: In all cases, non-union or loosening of implants was not observed. There were two screw breakages in two-level posterior fixation group, but bony union was obtained at the final follow-up. There were no significant differences in loss of anterior vertebral body height, correction loss, or change in adjacent discs. Also, in clinical evaluation, there was no significant difference in the neurological deficit of any patient during the follow-up period. CONCLUSIONS: In our study, two-level posterior fixation could be used successfully in selected cases of thoracolumbar burst fractures of 7 and 8 points in the load-sharing classification.

The impact of asymptomatic vertebral fractures on quality of life in older community-dwelling women: the São Paulo Ageing & Health Study

OBJECTIVES: The aim of this study was to investigate the impact of asymptomatic vertebral fractures on the quality of life in older women as part of the Sao Paulo Ageing & Health Study. METHODS: This study was a cross-sectional study with a random sample of 180 women 65 years of age or older with or without vertebral fractures. The Quality of Life Questionnaire of the European Foundation for Osteoporosis was administered to all subjects. Anthropometric data were obtained by physical examination, and the body mass index was calculated. Lateral thoracic and lumbar spine X-ray scans were obtained to identify asymptomatic vertebral fractures using a semi-quantitative method. RESULTS: Women with asymptomatic vertebral fractures had lower total scores [61.4(15.3) vs. 67.1(14.2), p = 0.03] and worse physical function domain scores [69.5(20.1) vs. 77.3(17.1), p = 0.02] for the Quality of Life Questionnaire of the European Foundation for Osteoporosis compared with women without fractures. The total score of this questionnaire was also worse in women classified as obese than in women classified as overweight or normal. High physical activity was related to a better total score for this questionnaire (p = 0.01). Likewise, lower physical function scores were observed in women with higher body mass index values (p<0.05) and lower physical activity levels (p,0.05). Generalized linear models with gamma distributions and logarithmic link functions, adjusted for age, showed that lower total scores and physical function domain scores for the Quality of Life Questionnaire of the European Foundation for Osteoporosis were related to a high body mass index, lower physical activity, and the presence of vertebral fractures (p<0.05). CONCLUSION: Vertebral fractures are associated with decreased quality of life mainly physical functioning in older community-dwelling women regardless of age, body mass index, and physical activity. Therefore, the results highlight the importance of preventing and controlling asymptomatic vertebral fractures to reduce their impact on quality of life among older women.

Ultrassonometria do calcâneo, densitometria óssea e morfometria vertebral em homens com idade acima de 60 anos / Quantitative ultrasound of the calcaneus, bone densitometry and vertebral morphometry in men over the age of 60 years

OBJETIVOS: Comparar a ultrassonometria do calcâneo com a densitometria óssea na avaliação de fraturas vertebrais morfométricas em homens acima de 60 anos. SUJEITOS E MÉTODOS: Foram analisados 96 homens com mais de 60 anos por meio de densitometria óssea da coluna, fêmur e rádio, radiografia lateral da coluna torácica e lombar e ultrassonometria do calcâneo. RESULTADOS: Cinquenta e um por cento dos homens apresentaram osteoporose e fraturas vertebrais. Foi observada correlação entre índice de stiffness e T-score da ultrassonometria e as densidades minerais ósseas (DMO) de todos os sítios. Quanto à presença de fraturas, identificou-se correlação com a DMO do rádio ultradistal e 33%. Por meio da curva ROC, observou-se acurácia da DMO do rádio UD na detecção de fraturas vertebrais. CONCLUSÕES: Nosso estudo mostrou correlação entre a ultrassonometria e a densitometria no diagnóstico de osteoporose em homens acima dos 60 anos. Também se identificou correlação entre fratura vertebral morfométrica e a DMO do rádio.

OBJECTIVES: To compare calcaneal ultrasonometry and bone densitometry in the evaluation of morphometric vertebral fractures in men over 60 years of age. SUBJECTS AND METHODS: We studied 96 men over 60 years of age by means of bone densitometry of the spine, femur and radius, lateral radiograph of the thoracic and lumbar spine, and calcaneal ultrasonometry. RESULTS: Fifty-one percent of men had osteoporosis and vertebral fractures. Correlation was found between ultrasonometry stiffness index, T-score and bone mineral density of the spine, femur and radius (p < 0.01). Regarding the presence of fractures, there was a correlation only with BMD of the ultradistal radius (UD) and radius 33%. ROC curve showed accuracy only of UD radius BMD in detecting vertebral fractures. CONCLUSIONS: Our study showed a correlation between osteoporosis diagnosis by ultrasonometry and densitometry in men over 60 years. It also showed a correlation between morphometric vertebral fracture and bone mineral density of the forearm.

Estudo experimental do sequenciamento das manobras da ligamentotaxia na descompressão do canal vertebral / 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.

Fratura da coluna vertebral tipo explosão na área da cauda eqüina: correlação entre função neurológica e alterações estruturais no canal vertebral / Spinal burst-type fracture on cauda equina area: correlation between neurological function and structural changes on spinal canal

OBJETIVO: Avaliar se há correlação entre o estreitamento traumático do canal vertebral e as possíveis fraturas associadas da lâmina, com o quadro neurológico inicial dos pacientes com fratura tipo explosão na área da cauda eqüina. MATERIAL E MÉTODOS: Foi realizada uma revisão retrospectiva de 42 pacientes que apresentaram 43 fraturas tipo explosão de L3, L4 e L5, no período compreendido entre janeiro de 1990 a dezembro de 2004. Os resultados foram avaliados de acordo com a disfunção neurológica inicial e o diâmetro sagital médio do canal vertebral acometido. RESULTADOS: A única variável preditiva independente do comprometimento neurológico foi o estreitamento do canal vertebral (p = 0,008). A porcentagem média de estreitamento do canal vertebral foi significativamente (p < 0,001) maior nos casos em que havia a fratura da lâmina associada. Porém, na análise múltipla, verificou-se que a fratura da lâmina não é um fator preditivo independente para que ocorra a lesão neurológica. CONCLUSÃO: O estreitamento do canal vertebral, causado pelo fragmento ósseo da fratura, com ou sem a associação de fraturas da lâmina, nas fraturas tipo explosão na área da cauda eqüina, tem correlação direta e estatisticamente significativa com a alteração da função neurológica.

PURPOSE: The purpose of this study was to determine whether a correlation exists between the traumatic narrowing of the spinal canal, potentially associated lamina fractures and the early neurological status of patients presenting to the hospital with burst fractures of the cauda equina area. MATERIAL AND METHODS: A retrospective review was carried out on 42 patients with 43 burst-type fractures of L3, L4 and L5 treated at a tertiary medical trauma center from January, 1990 to December, 2004. Results were based on comparisons made between the initial neurological deficit and the midsaggital diameter of the fractured vertebrae. RESULTS: The only predictive independent variable of the neurological deficit was the narrowing of the spinal canal (p=0.008). The average narrowing of the spinal canal was greater in patients with associated lamina fractures (p<0.001). However, multiple independent analyses did not establish lamina fractures as a predictive factor for neurological deficit. CONCLUSION: It was concluded that, in burst fractures of the cauda equina area, the acute traumatic spinal canal narrowing, with or without associated fractures of the lamina, shows a statistically significant positive correlation with the neurological deficit.

Estudo do posicionamento dos parafusos pediculares no tratamento das fraturas da coluna toracolombar

Nas últimas décadas, houve aumento no uso de instrumentação com parafusos pediculares no tratamento das fraturas da coluna toracolombar. Esse tipo de fixação tem a vantagem de estabilizar as três colunas de Denis, ao contrário das outras instrumentações até então utilizadas, porém apresenta como possível e temível complicação a possibilidade de penetração do canal vertebral, fratura dos pedículos, acometimento de raízes nervosas e lesões vasculares. Nosso trabalho visa avaliar se a tomografia computadorizada é um bom método de análise do posicionamento dos parafusos pediculares e as possíveis complicações na passagem cirúrgica dos mesmos. Foram estudados 19 pacientes, totalizando 134 parafusos, durante os período de novembro de 2002 até fevereiro de 2005, quanto a análise radiográfica, tomográfica e neurológica pré e pós-operatória. Como resultado, houve dois casos de lesão da parede lateral do pedículo no estudo tomográfico, sem repercussão clínica aos pacientes. Quanto ao déficit neurológico, nenhum paciente apresentou piora. Seis pacientes apresentaram melhora de seu status neurológico. Concluímos que a tomografia computadorizada é excelente exame de imagem para avaliar os parafusos pediculares, e que esse tipo de fixação foi seguro e de baixa morbidade, permitindo mobilização precoce do paciente.

In the last decades, there has been an increasing use of instruments with pedicular screws for treating thoracic-lumbar spine fractures. This kind of fixation has the advantage of stabilizing the DenisÆ three columns, as opposite to other instruments previously used, but it presents as a possible and feared complication the potential of vertebral channel penetration, pedicular fractures, involvement of nervous roots and vascular injuries. Our study aims to evaluate if computed tomography is a good analysis method for pedicular screws positioning and the potential complications of surgically passing them. Nineteen patients have been studied, totaling 134 screws, during the period ranging from November 2002 to February 2005, regarding X-ray, tomography and pre- and postoperative neurological function analyses. As a result, there were two cases of injury on pedicleÆs lateral wall at the tomography image, with no clinical repercussion to patients. Regarding neurological deficit, no patient showed a worse condition. Six patients presented with an improved neurological status. We concluded that computed tomography is an excellent imaging test for evaluating pedicular screws, and this kind of fixation was safe and showed low morbidity rates, allowing an early mobilization of the patient.

Percutaneous Vertebroplasty and Facet Joint Block

It is surprising that about 24% of patients with benign osteoporotic vertebral fracture die within a year from respiratory infection and urinary tract infection because of coughing and voiding difficulties, depending on the sites of compression fractures. We reviewed 500 patients on whom percutaneous vertebroplasty (PVP) was performed, at 612 levels in terms of patient selection, operation technique, medication, and clinical outcomes during the follow-up course for 2 yr study period. To confirm the most painful level among the multiple fracture sites, physical examination after facet joint block under the fluoroscope was the most reliable method. The mean total lumbar spine fracture threshold of bone mineral density was 0.81+/-0.05 g/cm2. The mean changes of numeric rating scale scores, Oswestry Disability Index except sex life, and Karnofsky performance status were -72.00, -83.50 and +60.62% in the osteoporosis group and -51.89, -45.02, and 69.03% in the tumor group. Complications related to the procedure were lateral spinal cord damage, transient paresthesia and transient hypotension. PVP with facet joint block is a profitable method for the vertebral compression fracture because of low risk and short duration of procedure with a high chance to result in pain relief and early mobilization.

Natural course of spontaneously reduced lumbo-sacral fracture-dislocation--a case report

We present a case of lumbosacral fracture-dislocation, which was spontaneously reduced during radiological examination. Such rapid reduction is, however, not reliable for long-term stability. We would like to report this case briefly because spontaneous reduction of lumbosacral fracture-dislocation has not been reported previously.