RESUMEN
Resumen: Introducción: Estudio prospectivo en pacientes afectos de hernia discal lumbar L5 S1 tratados mediante la U-Force interespinosa N6. El espaciador interespinoso denominado "U" está realizado en titanio y es colocado entre las apófisis interespinosas. Material y métodos: 50 pacientes operados de hernia discal lumbar fueron evaluados; 25 pertenecían al grupo U-N6 y 25 sólo fueron tratados con microcirugía. Se les realizó valoración clínica y estudios radiológicos seriados. Todos los individuos tuvieron un seguimiento durante dos años (2013-2014). Resultados: Nuestro estudio revela que el uso del dispositivo fue más efectivo (estadísticamente significativo) para el retraso de la inestabilidad que sólo la técnica quirúrgica (p < 0.01). Permitió su colocación en 90% de los sujetos. Conclusión: El uso de este dispositivo retrasa el colapso vertebral y, por ende, la inestabilidad del segmento operado. Noventa por ciento de los casos del grupo N6 presentan el dispositivo a nivel de L5 S1 versus 60% del grupo histórico con otros dispositivos (2004-2011).
Abstract: Introduction: We conducted a retrospective study in patients with disc herniation and compared the results obtained in individuals treated with the U device N6 with those acquired in patients treated without any device. The U device is a titanium alloy implant that is placed between the spinous processes. Material and methods: In a cohort of 50 patients with degenerative lumbar disc, 25 underwent surgical treatment in which the U device was placed and 25 control individuals were treated with discectomy alone. Patients underwent serial follow-up evaluations, and radiographic assessment was used to determine the outcome. Up to two years of follow-up data were obtained in all patients (2013-2014). Results: Statistically significant improvement was seen in patients treated with the coflex device in the management of lumbar disc degeneration to avoid lumbar instability in the future (p < 0.01). It allowed its placement in 90% of the patients. Conclusions: Our study shows that the coflex device was more effective than the discectomy group in the management of lumbar instability. Ninety percent of the cases of the N6 group present the device at L5 S1 versus 60% of the historical group with other devices (2004-2011).
RESUMEN
Objective To simulate clinical operation and investigate feasibility of Coflex dynamic device for fixing L5/S1 segment of lower lumbar degenerative diseases. Methods The lower lumbar-sacral digital model was extracted from platform of the second generation of Chinese Digitized Human “Male No.23” data set, and three finite element (FE) models (the model of normal lower lumbar sacrum, L4/5 and L5/S1 segment fixed with Coflex) were developed respectively using a series of CAX software. According to the spinal three-column loading theory and the lower lumbar physiological behaviors, FE model tests were analyzed, validated and compared under the physiological load of upright standing, anteflexion and extension. Results The FE models of normal lower lumbar sacrum (Healthy), Coflex fixed-L4/5 segment (L4/5), Coflex fixed-L5/S1 segment (L5/S1) were developed, respectively. Based on biomechanical indexes (stability and compatibility) of the controlled trial for the FE model, the two Coflex-fixed FE models showed similar biomechanical effects for fixing the lower lumbar. Conclusions The controlled trials of FE models provide biomechanical evidence for the fixation of lower lumbar L5/S1 segment by Coflex dynamic device, which is of significance for application of Coflex in fixing L5/S1 segment in clinic.