Monosegmental Hepatobiliary Fibropolycystic Disease Mimicking a Mass: Report of Three Cases

Hepatobiliary fibropolycystic diseases are a unique group of entities involving the liver and biliary tract, which are caused by abnormal embryologic development of the ductal plates at various stages. We experienced strange hepatobiliary fibropolycystic diseases with a complex mass composed of malformed ducts and biliary cysts, which did not belong to, and were different from, previously known malformations. They were unique in imaging and histologic features. We herein report three cases of monosegmental hepatobiliary fibropolycystic disease mimicking a mass.

Biomechanical comparison of monosegmental and short transpedicular fixation for stabilization of thoracolumbar fractures / 医用生物力学

Objective To establish the monosegmental transpedicular fixation model and short segmental fixation model by three-dimensional finite element technique, and evaluate the biomechanical properties of monosegmental transpedicular fixation for thoracolumbar fractures and verify its feasibility for application. Methods T10-L2 motion segment of a young healthy subject was used to establish the normal finite element model. The superior 1/2 cortical bone of the T12 segment was removed and superior 1/2 cancellous bone of the same vertebrae was assigned material property of the injured bone to simulate the thoracolumbar fracture. Transpedicular screw fixation of the T11 and T12 segment was performed in monosegmental fixation model. T11 and L1 segment were instrumented in the short segmental fixation model. All the four finite element models were applied with loading of axial compression, anteflexion, extension, lateroflexion and axial rotation, respectively. Motion difference of each functional unit and the stress of implants were measured to evaluate biomechanical behaviors of monosegmental fixation. Results The motion difference of all the functional units (T10-11, T11-12, T12-L1) in the fractured model was obviously increased under all loading conditions as compared to the normal model, but the motion difference in the fractured models was decreased after monosegmental fixation and short segmental fixation, and no significant differences were found between monosegmental fixation and short segmental fixation. The stress on screws in monosegmental fixation model was significantly lower than that in short segmental fixation under axial compression and anteflexion, but the stress on screws of two fixation models had no significant difference under extension, lateroflexion and axial rotation. The stress on the rods of monosegmental fixation model was apparently higher than that of short segmental fixation under extension and lateroflexion, and lower under axial rotation, but no significant difference was found for two fixation models under axial compression and anteflexion. Conclusions Monosegmental transpedicular screw fixation would give the similar stabilization as short segmental fixtion and could be an effective alternative to treat incomplete fractures in thoracolumbar spine.

Fijación posterior monosegmentaria en fracturas de la columna toracolumbar / Fixação posterior monossegmentar nas fraturas da coluna toracolombar / Posterior monosegmental fixation in thoracolumbar spine fractures

OBJETIVO: Evaluar los resultados de la fijación pedicular posterior monosegmentaria en el manejo de las fracturas toracolumbares, buscando las variables que influyen en la falla de esta técnica. MÉTODOS: Serie de casos operados en un período de 10 años. Se identificaron 33 pacientes. 5 fueron eliminados por insuficiencia de datos. 28 pacientes fueron evaluados, la edad promedio fue 36 años con una mediana de seguimiento de 30 meses. Se definió fracaso radiológico del tratamiento como falla del implante y/o un aumento de la cifosis local > o = a 10º en el último control radiográfico respecto al posoperatorio inmediato. Se definió mal resultado clínico como: el desarrollo de complicaciones, el reposo laboral mayor al p90 de la muestra y/o la incapacidad para retornar al trabajo. RESULTADOS: Cuatro pacientes (14 por ciento) presentaron falla radiológica del tratamiento. Tuvimos tres complicaciones precoces y 2 tardías, con un 92,8 por ciento de retorno al mismo trabajo tras un promedio de 3,4 meses de reposo laboral. No observamos correlaciones estadísticas al analizar las variables estudiadas con respecto a la falla de la cirugía. Conclusión: La fijación monosegmentaria tiene buenos resultados en el tratamiento de las fracturas toracolumbares. En nuestra serie, tuvimos buenos resultados clínicos en un 93 por ciento y radiológicos en el 86 por ciento de los pacientes. No observamos correlaciones estadísticas con respecto a la falla de la cirugía, sin embargo, los pacientes que fallaron radiológicamente tenían mayor cifosis preoperatoria y/o mayor corrección posoperatoria.

OBJETIVO: Avaliar os resultados da fixação pedicular posterior monossegmentar no manejo das fraturas toracolombares, buscando as variáveis que influenciam a falha da técnica. MÉTODOS: Série de casos operados em um período de 10 anos. Foram identificados 33 pacientes. Cinco foram eliminados devido à insuficiência de dados. Dos 28 pacientes avaliados, a idade média foi de 36 anos com média de seguimento de 30 meses. O fracasso radiológico do tratamento foi definido como uma falha do implante e/ou aumento > ou = 10º de cifose segmentar no último controle radiográfico respeitando as medidas obtidas no controle pós-operatório. Definiu-se como mal resultado clínico: desenvolvimento de complicações, a necessidade de afastamento laboral maior do que o p90 do resto da amostra e/ou impossibilidade de retorno ao trabalho. RESULTADOS: Quatro pacientes (14 por cento) apresentaram insuficiência radiológica no tratamento. Tivemos três complicações precoces e duas tardias. 92,8 por cento dos pacientes retornaram ao mesmo trabalho após um tempo médio de 3,4 meses de repouso laboral. Não foram observadas correlações estatísticas ao analisar as variáveis em relação ao fracasso da cirurgia. CONCLUSÃO: A fixação monossegmentar obteve bons resultados no tratamento das fraturas toracolombares. Em nossa série tivemos bons resultados clínicos em 93 por cento e radiológicos em 86 por cento dos pacientes. Não foram observadas correlações estatísticas em relação ao fracasso da cirurgia, no entanto, nos pacientes que tiveram falha radiográfica observamos maior cifose pré-operatória e/ou maior correção pós-operatória.

OBJECTIVE: To evaluate the results of monosegmental fixation for the treatment of thoracolumbar fractures, to identify possible variables that influence treatment failure. METHODS: Case series of patients operated in a 10-year period. 33 patients were identified. Of these, 5 were eliminated due to insufficient data. 28 patients were evaluated, with a mean age 36 years and median follow up of 30 months. We defined radiological treatment failure as > or = 10 degrees of increased local Kyphosis in the radiographs in the last follow-up, compared with the measurements from the initial radiographs performed postoperatively or failure of the implant. We defined poor clinical results as complications, time out of work > to P 90 of the study group and/or inability to return to work. RESULTS: 4 patients (14 percent) presented radiological treatment failure. 3 suffered acute complications, and had 2 delayed complications. 92.8 percent of the patients returned to their jobs, with a mean postoperative time out of work of 3.4 months. no statistically significant differences were detected among the different evaluated variables evaluated and the levels of treatment failure. CONCLUSION: Posterior monosegmental fixation has good results in the treatment of thoracolumbar fractures. In our series we had good clinical results in 93 percent and radiological results in 86 percent of the patients. We did not find any variable that could be correlated with treatment failure, although the cases considered failures according to the radiological exams had a major preoperative kyphosis and a greater postoperative kyphosis correction than those who did not.

Assessment for the stability of fracture thoracic lumber spine(T11~L3) fixed with crossbar equipped pedicle screws / 医用生物力学

Objective To determine the stability of fracture thoracic lumber spine (T11~L3) fixed with crossbar equipped pedicle screws. MethodThe thoracic lumber spine segments (T11~L3) were obtained from calves. A wedge cut was performed on L1 vertebral body to produce a model resembling severe vertebral compressive fracture. Some of the fracture spine segments were fixed with pedicle screws with and without crossbar. Thus, 4 types of spine segments were available: (1) normal segments; (2) unfixed fracture; (3) fracture fixed with crossbar equipped pedicle screws and (4) fracture fixed with pedicle screws without crossbar. The segmental stability was determined by measuring the range of motion (ROM) at directions of flexion/extension, left/right axial rotation and left/right lateral bending using a three dimensional laser scanner. Each ROM was standardized into a stability potential index (SPI) for the comparison among 4 groups. ResultsCompared to unfixed fracture, both fixations significantly increase stability of injuried specimens at each motion direction. The stability of injured segment fix with crossbar equipped pedicle screws is higher than that fixed without crossbar, but the difference does not reach statistically significant. ConclusionsPedicle screw fixation can significantly increase the stability of fracture spine. However, crossbar may not play a further role in raising fixative stability.

Two Cases of Monosegmental Pedicle Screw Fixation for Thoraco-lumbar Fracture(Three-column Injury), and a Review of the Literature

The management of thoraco-lumbar fractures remains controversial. Different authors have advocated immobilization, external bracing or internal fixation by either anterior or posterior approaches. To stabilize the fracture and avoid an unne cessary fixation of an uninjured segment, posterior monosegmental fixation was performed in Type B1 fractures according to the classification of Magerl et al, with nearly intact vertebral body for load support. Two patients underwent fixation with 4 titanium pedicle screws, one level above and directly into the fractured vertebra body. Patients had a stable fixation at 6 months following surgery. No patients experienced neurological deficit or had developed a delayed kyphotic deformity. Single level fixation for selected cases of thoracolumbar fracture(Type B1 fractures) may be considered as an effective procedure to obtain fixation and fusion. But it is necessary to get a further follow-up period, further cases and especially biomechanical support.