Objective: In this paper we report the clinical and radiological results of lumbar intervertebral disk (IVD) replacement with M6-L for the treatment of patients with IVD degeneration. Methods: One hundred and fifty-six patients with IVD degeneration were operated with the one level implantation of an M6-L prosthesis at three neurosurgical departments, in Irkutsk, Krasnoyarsk and Vladivostok. We assessed pain intensity (VAS), the Oswestry disability index (ODI) and outcomes by the Macnab scale up to 36 months after surgery. Instrumental data were used to assess range of motion in the operated segment and heterotopic ossification by the McAfee-Suchomel classification. Results: The average VAS before surgery was 6.9 ± 1.6 cm. After surgery, this value reduced significantly, to an average of 1.3 ± 1.2 cm (p<0.001). The average ODI before surgery was 40.2 ± 6.9%, and after IVD arthroplasty, this indictor improved to 12.3 ± 6.1% (p <0.001). Range of motion in the operated segment at baseline averaged 36.8 ± 2.6 o , and within 36 months after the operation, this had increased to 41.2 ± 2. McAfee-Suchomel. Resultados: El valor promedio de la EVA para el dolor antes de la cirugía fue de 6,9 ± 1,6 cm. Después de la cirugía, ese valor tuvo una reducción significativa, en promedio de 1,3 ± 1,2 cm (p < 0,001). El ODI promedio antes de la cirugía fue de 40,2 ± 6,9% y después de la artroplastia del IVD ese índice mejoró para 12,3 ± 6,1% (p < 0,001). El rango de movimiento del segmento operado al inicio del estudio fue en promedio 36,8 ± 2,6 o y 36 meses después de la cirugía, aumentó a 41,2 ± 2,9 o . Durante toda el seguimiento se observaron signos de osificación heterotópica grave (13,4%, n = 21) o moderada (10,2%, n = 16 RESUMEN Objetivo: En este trabajo, relatamos los resultados clínicos y radiológicos de la sustitución de disco intervertebral lumbar (IVD) con M6-L para tratamiento de pacientes con degeneración de IVD. Métodos: Ciento cincuenta y seis pacientes con degeneración de IVD fueron operados con la implantación de prótesis M6-L en un nivel, en tres departamentos de neurocirugía de Irkutsk, Krasnoyarsk y Vladivostok. Se evaluó la intensidad del dolor (EVA), el Índice de Discapacidad de Oswestry (ODI) y los resultados por escala de Macnab hasta 36 meses después de la cirugía. Los datos de instrumentación se utilizaron para evaluar el rango de movimiento en el segmento operado y la osificación heterotópica mediante la clasificación de

Objective: The article presents an analysis of the clinical efficacy and causes of unsatisfactory outcomes of surgical treatment in patients with degenerative diseases of the lumbosacral junction of the spine. Methods: Patients were allocated to one of three groups, depending on the method of surgical intervention on the lumbosacral junction: 1) (n=352) - operated by the method of microsurgical discectomy; 2) (n=83) - operated with the use of artificial IVD prostheses; 3) (n = 183) - operated with the use of interbody fusion and posterior rigid stabilization. To investigate the causes of unsatisfactory outcomes, a correlation analysis was conducted of long-term clinical outcomes with preoperative instrumental parameters in the operated segment, surgical tactics used, and the development of complications. Results: It is determined that long-term “good” clinical outcomes are associated with individual preoperative parameters of the lumbosacral junction of the spine - linear displacement, sagittal angulation, height of the interbody space, degree of IVD degeneration by ADC. Conclusion: In degenerative diseases of the lumbosacral junction of the spine, the detailed analysis of long-term clinical outcomes enable the identification of the causes that affect the development of unsatisfactory outcomes, which are individual morphostructural changes in the lower lumbar segment: the amplitude of the segmental angle, the angle of the lumbar lordosis, the degree of linear displacement of the vertebrae, the height of the interbody space, and ADC. Complex clinical and instrumental analysis enabled us to determine possible surgical tactics. Level of Evidence II; Prognostic Studies— Investigating the Effect of a Patient Characteristic on the Disease Outcome.

Objective: To analyze the impact of the relationship between tropism and angulation of the lower lumbar facet joints on a remote clinical outcome after dynamic and rigid surgical interventions. Methods: Patients with degenerative diseases of the lower lumbar spine were subdivided into three groups, according to the method of surgical treatment: 1) (n=48) the use of an artificial prosthesis intervertebral disc (IVD); 2) (n=42) the use of interbody fusion combined with transpedicular and transfacet stabilization; 3) (n=51) the use of interbody fusion and bilateral transpedicular stabilization. Analysis was performed of the remote clinical parameters and neuroimaging characteristics before the operation was performed. Results: When analyzing clinical and instrumental parameters, a significant correlation was found between the long-term outcomes of surgical treatment on the VAS and Oswestry scales and the neuroimaging data on angulation and tropism of the facet joints (FJ). Conclusions: The data obtained testify to the importance of preoperative diagnosis of tropism and angulation of the lower lumbar facet joint, which enables differentiated surgical tactics to be selected, and remote clinical outcomes to be optimized. In the presence of neuroimaging parameters of Facet Joint angulation of less than 600, regardless of the presence of tropism, it is possible to perform total arthroplasty of IVD. When neuroimaging parameters of Facet Joint angulation of more than 600 are detected, rigid stabilization of the operated segment is recommended, while in the absence of tropism of Facet Joints, a contralateral transfacetal fixation is possible; in the presence of tropism, it is expedient to perform bilateral transpedicular stabilization. Level of Evidence II; Prognostic Studies—Investigating the Effect of a Patient Characteristic on the Outcome of Disease.