Initial clinical experience with a next-generation artificial disc for the treatment of symptomatic degenerative cervical radiculopathy.

BACKGROUND: A feasibility trial was conducted to evaluate the initial safety and clinical use of a next-generation artificial cervical disc (M6-C artificial cervical disc; Spinal Kinetics, Sunnyvale, CA) for the treatment of patients with symptomatic degenerative cervical radiculopathy. A standardized battery of validated outcome measures was utilized to assess condition-specific functional impairment, pain severity, and quality of life. METHODS: Thirty-six consecutive patients were implanted with the M6-C disc and complete clinical and radiographic outcomes for 25 patients (mean age, 44.5 ± 10.1 years) with radiographically-confirmed cervical disc disease and symptomatic radiculopathy unresponsive to conservative medical management are included in this report. All patients had disc-osteophyte complex causing neural compression and were treated with discectomy and artificial cervical disc replacement at either single level (n = 12) or 2-levels (n = 13). Functional impairment was evaluated using the Neck Disability Index (NDI). Evaluation of arm and neck pain severity utilized a standard 11-point numeric scale, and health-related quality of life was evaluated with the SF-36 Health Survey. Quantitative radiographic assessments of intervertebral motion were performed using specialized motion analysis software, QMA (Quantitative Motion Analysis; Medical Metrics, Houston, TX). All outcome measures were evaluated pre-treatment and at 6 weeks, 3, 6, 12, and 24 months. RESULTS: The mean NDI score improved from 51.6 ± 11.3% pre-treatment to 27.9 ± 16.9% at 24 months, representing an approximate 46% improvement (P <.0001). The mean arm pain score improved from 6.9 ± 2.5 pre-treatment to 3.9 ± 3.1 at 24 months (43%, P =.0006). The mean neck pain score improved from 7.8 ± 2.0 pre-treatment to 3.8 ± 3.0 at 24 months (51%, P <.0001). The mean PCS score of the SF-36 improved from 34.8 ± 7.8 pre-treatment to 43.8 ± 9.3 by 24 months (26%, P =.0006). Subgroup analyses found that patients treated at single level and those with a shorter duration of symptoms showed better functional results. By 24 months, the mean range of motion (ROM) value at the treated level had returned to approximately pretreatment levels (12.2° vs 11.1°). There were no serious device-related adverse events, surgical re-interventions or radiographic evidence of heterotopic ossification, device migration, or expulsion in this study group. CONCLUSIONS: These findings indicate substantial clinical improvement for all function, pain, and quality of life outcomes in addition to maintenance of ROM and increase in disc height at the treated level(s). The findings also exhibit an acceptable safety profile, as indicated by the absence of serious adverse events and reoperations following arthroplasty with a next-generation artificial cervical disc replacement device.

[Surgical treatment of craniocervical instability. Review paper]. / Tratamiento quirúrgico para la inestabilidad craneocervical. Trabajo de revisión.

The concept of spinal instability is still controversial. Anatomical, biomechanical, clinical and radiographic variants are involved and make the definition complicated. There are solid diagnostic bases in cases of fractures and degenerative disorders; however, pure spinal instability is still under study. The latter may be defined as increased mobility that goes beyond the physiological limits of one vertebra over another in at least one of the three spinal planes of motion. In the case of the craniocervical region, its understanding becomes even more challenging, since its anatomy and physiology are more complex and it is more mobile. Surgical treatment is possible with either an anterior or a posterior approach. Best results are obtained with occipitocervical or atlantoaxial stabilization through a posterior approach, since the anterior one has its limitations. For example, a transoral approach with a bone graft provides compression strength but does not enable immediate appropriate fixation and involves the risk of infection. The choice of the surgical approach must consider the patient's medical status, the specific spine levels involved, the extent of neurological compromise, the X-ray abnormalities and the individual pathology. The goals of surgery are achieved through an appropriate anatomical alignment, assuring the protection of the neural elements and achieving proper spine stabilization with as much preservation of the mobile vertebral segments as possible.

External fixation for dynamic correction of severe scoliosis.

BACKGROUND CONTEXT: The ideal treatment for scoliosis may be the correction of the factors that cause the disease. An external fixation device was used in 12 patients to achieve a correction by dynamic distraction, compression and derotation of the curve. Follow-up was done over a 7-year period. PURPOSE: To describe the treatment of inflexible and severe scoliosis by special correction with external fixation. STUDY DESIGN/SETTING: This was a prospective, longitudinal and descriptive study, with a follow-up period of 7 years. PATIENT SAMPLE: Twelve patients (9 female, 3 male) from the National Orthopaedic Institute Spine Service in external consultation. OUTCOME MEASURES: Radiographic measurements with the scoliosis angulation of Cobb's method were used before surgery, after surgery and in the final follow-up period. METHODS: The surgical procedure consisted of two stages, anterior and posterior approach, dissectomies, vertebrectomy at the apex, spinal column shortening and the placement of an external stabilization device. Progressive correction of the curve was done by a daily increase in distraction (3 mm/day). When the correction was finished, a different internal fixation device was used to maintain the correction. The time between initial treatment and final correction was 50 days. Ten thoracic curves, one thoracolumbar curve and one lumbar curve were treated, with an average of 93 degrees. All patients had kyphosis with an average of 89 degrees. Vertebral rotation was not found in two patients. RESULTS: Average correction of scoliosis was 52.9% and of kyphosis, 29%. Vertebral rotation in eight cases was corrected. There were no neurological irreversible lesions in any patient. There was one infection. Using an evaluation result scale, there were 2 excellent, 6 good and 4 fair outcomes. The average loss of correction was 5 degrees. CONCLUSION: The results suggest that the use of an external stabilization device with controlled compression on the convexity and distraction on the concavity of the curve can achieve a correction of up to 50% in scoliosis, 30% in kyphosis and 1 degree in the rotation of the spine.

Treatment of thoracolumbar burst fractures by vertebral shortening.

Burst fractures may be stable or unstable, so the choice of treatment may be controversial; almost all cases are surgical type. Deciding on the best method and approach is difficult, due to the many possible options and the fact that good results are achieved in only 60-70% of cases. The main problems to be resolved are the residual kyphosis or the recurrence due to loss of reduction. This is a prospective, observational, longitudinal and descriptive study of six patients two men and four women, mean age 46 years - who scored 7 or more points according to the load distribution classification, and were treated with vertebral shortening by a posterior approach and transpedicular fixation with INO plates. Follow-up was for a period of 2 years, and included evaluating pre- and postoperative stability and kyphosis among other data. The results showed a reduction in the mean fracture angle from 17 degrees preoperatively to 1 degrees postoperatively. Full stability was achieved in five patients, and incomplete stability in one patient, who recovered with the use of a corset. There was evidence of arthrodesis in all six patients within 9 months. The use of an anterior approach to treat burst fractures is well recognized; however, treatment with vertebral shortening using a posterior approach has the advantages of less bleeding, shorter surgical time and less residual kyphosis, as a result of putting together two flat surfaces of healthy bone. The residual kyphosis in the present series, after the 2-year follow up, was less than 1 degrees , which is lower than the 5 degrees - 10 degrees reported in the literature.

Resultados y complicaciones del uso de tornillos transpediculares de la columna vertebral en el INO / Results and complications of transpedicle screws in the vertebral spine at INO

El uso de sistemas rígidos y semirrígidos, en la osteosíntesis vertebrañ mediante tornillos transpediculares proporciona una estabilización inmediata, sostén mecánico para la artrodesis o consolidación de fracturas, no requiere presencia del arco neural para su fijación y no invade el conducto raquídeo. Se informa de los resultados y complicaciones con implantes fijados con tornillos prediculares de abril de 1991 a agosto de 1992, en el servicio referido. Los implantes utilizados fueron: sistema Luque II en 2 casos: Luque III en 8; Roy-Camille en 1; e INO en 35. el tipo de tornillo fue Luque II: 8; Luque III: 36; cortical AO 4.5: 25; INO: 217; con un total de 278. Seis tornillos como promedio por paciente y 39 minutos como promedio en su colocación, tomando el total del tiempo quirúrgico como referencia. Implantes colocados: Luque II: 4 placas (5 orificios); Luque III: 12 barras (2 en 4 niveles, 4 en 2 niveles y 6 de 3 niveles). Roy-Camille: 2 placas (5 orificios), e INO: 20 placas 2 orificios: 32 placas; 3 orificios: 14 placas; 4 orificios: 4 placas; 5 orificios. El número de tornillos mal colocados fue: Luque III: 1 (2.7 por ciento); Cortical AO 4.5, 2 (2.8 por ciento); e INO: 17 (7.8 por ciento), en el total el índice de error fue de 7.6 por ciento. Existió una radiculits en un paciente, hematoma en dos pacientes, así como una defunción debido a causas ajenas a la patología vertebral. Los resultados según la tabla de Thalgott fueron: excelentes 22 casos (47.8 por ciento); buenos 22 (47.8 por ciento) y malo 1 (2.1 por ciento). Actualmente se han visto rápidos avances en los dispositivos de fijación para la columna vertebral toracolumbosacra pero el implante ideal que llene todos los requisitos para su estabilización aún no se ha encontrado

Tratamiento de la espondilólisis con espondilolistesis menor de 25 por ciento mediante reparación del defecto / Spondylolysis treatment with less than 25 percent spondylolisthesis by defect repair

El tratamiento de la espondilósis lumbar, con espondilolistesis menor de 25 por ciento, es una artrodesis muy usada que produce la consecuente limitación en la movilidad, menor soporte y poca tolerancia para el esfuerzo. Con el uso de sistemas de fijación transpedicular se reducen estas complicaciones además del riesgo de pseudoartrosis, estabilizando la columna, aliviando la sintomatología, la biomecánica de la columna y propiciando un mayor porcentaje de consolidación. En este estudio preliminar, se trataron tres pacientes que no respondieron a los tratamiento conservadores descomprimiendo, mediante este método, las raíces nerviosas sin que hasta el momento se observen complicaciones postoperatorias, por lo que se recomienda el uso de estos fijadores

Hemiartrodesis anterior y posterior y hemiepifisiodesis de la convexidad en el tratamiento de la escoliosis idiopática / Posterior and anterior hemi-arthrodesis and hemi-epiphysiodesis on the convexity for treatment of the idiopatic scoliosis

Este trabajo prospectivo tiene como objetivo desarrollar una técnica que permita la corrección de la escoliosis idiopática con mínima repercución funcional de la columna y mediante una artrodesis de extensión reducida. Esta revisión es preliminar y presenta a los primeros siete pacientes con escoliosis idiopática, tratados mediante hemiartrodesis anterior y posterior y hemiepifisiodesis en el lado convexo de la deformidad. La edad de los pacientes varió de ocho a 15 años y la curva fue torácica, tóraco-lumbar o lumbar de 25 a 50 grados, con componentes en las torácias, de xifosis hasta de 60 grados. Se les hizo hemiepifisiodesis anterior, hemiatrodesis anterior por vaciamiento de cuerpos vertebrales a través del pedículo y artrodesis intersomática por resección del disco. Se completó la artodesis posterior y lateral con el mismo hueso resecado de los cuerpos vertebrales. Todos usaron corsé TLSO por seis meses después de la cirugía. Después de un primer periodo de un año de observaciones se ha observado inicio de corrección, según la edad de los pacientes, de uno a nueve grados