Evaluación del desempeño de una nueva prótesis de disco intervertebral cervical mediante el método de los elementos finitos / Evaluation of a new cervical intervertebral disc prosthesis using the finite element method

Introducción: El tratamiento inicial de la cervicalgia por degeneración de los discos intervertebrales es conservador, pero en caso de fallo la discectomía es la opción quirúrgica habitual, sustituyendo el disco por un injerto óseo u otra estructura que cumpla total o parcialmente las funciones del primero. El Servicio de Neurocirugía del Hospital General Camilo Cienfuegos de Cuba ha diseñado un nuevo modelo de prótesis de disco intervertebral cervical para tratar esta enfermedad. Objetivo: Evaluar el desempeño mecánico de la prótesis diseñada a través del método de los elementos finitos bajo las cargas habituales de la columna cervical. Material y Métodos: Se realizó un estudio experimental mediante la simulación numérica, según el método de los elementos finitos, sometiendo la prótesis a las cargas axiales recomendadas por las normas ASTM F2423-11e ISO 18192-1.2011 mediante el software Free CAD 0.18. Resultados: Los mayores esfuerzos soportados por la prótesis en la posición neutral, flexión anterior y flexión lateral fueron de 28.79 MPa, 52.29 MPa y 55.59 MPa respectivamente. La prótesis no sufrió ninguna fractura al no sobrepasar los valores anteriores al límite elástico del material que la constituye. La mayor deformación descrita fue de 1 m. Conclusiones: La mayor concentración de esfuerzos en la prótesis se ubicó en el punto de contacto de la cavidad prismática de la pieza superior al hacer contacto con el prisma de la pieza inferior. El dispositivo diseñado no sufrió ninguna deformación significativa ni se fracturó ante las cargas aplicadas(AU)

Introduction: The initial treatment of cervicalgia due to degeneration of the intervertebral discs is conservative, but in case of failure, discectomy is the usual surgical option, replacing the disc with a bone graft or another structure that fully or partially fulfills the functions of the former. The Neurosurgery Service of the Camilo Cienfuegos General Hospital in Cuba has designed a new cervical intervertebral disc prosthesis model to treat this disease. Objective: To evaluate the mechanical performance of the prosthesis designed through the finite element method under the usual loads of the cervical spine. Material and Methods: An experimental study was carried out using numerical simulation according to the finite element method, subjecting the prosthesis to the axial loads recommended by ASTM F2423-11e ISO 18192-1.2011 standards using Free CAD 0.18 software. Results: The greatest efforts supported by the prosthesis in the neutral position, anterior flexion and lateral flexion were 28.79 MPa, 52.29 MPa and 55.59 MPa, respectively. The prosthesis did not suffer any fracture as it did not exceed the values ​prior to the elastic limit of the material that constitutes it. The greatest deformation described was 1 956;m. Conclusions: The highest concentration of efforts in the prosthesis was located at the point of contact of the prismatic cavity of the upper part when making contact with the prism of the lower part. The designed device did not undergo any significant deformation or fracture at the applied loads(AU)

Tratamiento de la hernia discal cervical. Hospital Provincial General Camilo Cienfuegos de Sancti Spíritus / Cervical disc herniation treatment at Camilo Cienfuegos General Provincial Hospital in Sancti Spíritus

RESUMEN Fundamento: La enfermedad degenerativa cervical produce una variedad de síntomas clínicos que pueden ser tratados de forma no quirúrgica, sin embargo en ocasiones la cirugía es necesaria. La técnica quirúrgica más empleada para tratar esta enfermedad es la discectomía con artrodesis. El tratamiento adecuado de la hernia discal cervical depende de una adecuada selección de la técnica quirúrgica y su correcta realización. Objetivo: Caracterizar el tratamiento quirúrgico de la hernia discal cervical en el Hospital Provincial General Camilo Cienfuegos de Sancti Spíritus en el período: enero de 2015 a diciembre de 2018. Metodología: Se realizó un estudio prospectivo en el Hospital Provincial General Camilo Cienfuegos de Sancti Spíritus de enero 2015 a diciembre 2018. La población de estudio: todos los pacientes que acudieron a la consulta externa de neurocirugía del hospital refiriendo cervicalgia o cervicobraquialgia; la muestra: 51 pacientes diagnosticados por resonancia magnética nuclear de hernia discal cervical y que se les realizó al menos una discectomía cervical. Resultados: De los pacientes el 62.8 % eran mujeres y el 33.3 % tenía una edad comprendida entre 51-60 años. El espacio intervertebral más afectado fue C5-C6 (43.7 %). La técnica quirúrgica que predominó fue la discectomía con colocación de injerto autólogo (79.7 %). La complicación más frecuente fue la expulsión del injerto (3.9 %). Conclusiones: El comportamiento de la hernia discal en cuanto al sexo, edad y nivel afectado fue similar al descrito en la bibliografía. La técnica quirúrgica más empleada fue la artrodesis con injerto autólogo de cresta ilíaca. Las complicaciones presentadas fueron infrecuentes.

ABSTRACT Background: Cervical degenerative disease produces a variety of clinical symptoms that can be treated by a non-surgical way, however sometimes surgery is necessary. The most widely used surgical technique to treat this disease is discectomy with arthrodesis. The proper treatment of cervical disc herniation depends on an adequate selection of the surgical technique and its correct performance. Objective: To characterize the surgical treatment of cervical disc herniation at Camilo Cienfuegos General Provincial Hospital in Sancti Spíritus in the period: January 2015 to December 2018. Methodology: A prospective study was carried out at Camilo Cienfuegos General Provincial Hospital in Sancti Spíritus from January 2015 to December 2018. The study population: all the patients who attended the hospital outpatient neurosurgery consultation referring cervicalgia or cervicobraquialgia; the sample: 51 patients diagnosed with cervical disc herniation and performed at least one cervical discectomy. Results: Of the patients, 62.8 % were women and 33.3 % were between 51-60 years old. The most affected intervertebral space was C5-C6 (43.7 %). The predominant surgical technique was discectomy with autologous graft placement (79.7 %). The most frequent complication was the expulsion of the graft (3.9 %). Conclusions: The behavior of the herniation disc concerning sex, age and affected level was similar to that described in the literature. The most widely used surgical technique was arthrodesis with an autologous iliac crest graft. The complications presented were infrequent.

Cervical Disc Herniation and Central Horner Syndrome

Central Horner syndrome is a rare condition, comprising a unique pathophysiological phenomenon. It results from vascular lesions, head or thoracic trauma. We describe a case of Horner syndrome associated to cervical disc herniation, and first-order neuron compression. To our knowledge, this is the second case reported to date in the literature.

A síndrome de Horner central é uma condição rara, que compreende um fenómeno fisiopatológico singular. Resulta de lesões vasculares, trauma cerebral ou torácico. Descrevemos um caso de síndrome de Horner associado a hérnia de disco cervical, com lesão de primeiro neurónio. De acordo com a revisão, é o segundo caso reportado na literatura.

Traumatic extrusion of C5-C6 intervertebral disc associated to mielopathy without bone lesion: report of 2 cases and review

The authors reports two cases of cervical disc herniation caused by trauma without osseous lesions in articular facets, vertebral bodies or dislocations. It constitutes uncommon lesions in spinal cord injury. The literature is reviewed.

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.