[Results of the surgical treatment of atlantoaxial instability]. / Resultado en el tratamiento quirúrgico de la inestabilidad atlantoaxoidea.

BACKGROUND: Instability of the cervical spine is defined as an increase in flexibility farther than the physiological limits of one vertebra over another in some of its axes, conditioning symptoms for the patient. Traumatic, degenerative, metabolic and neoplastic causes have all been identified. METHODS: A retrospective, longitudinal, observational and descriptive study was carried out on patients surgically intervened specifically for atlantoaxial instability from January 1993 to May 2002, with a minimum 5-year follow-up. RESULTS: Eleven patients were evaluated. Ages ranged from 25 to 75 years (average age 56 years) with a female predominance. Etiology was iatrogenic in six cases, and there were four cases of rheumatoid arthritis and one case due to trauma. In all cases, fixation was accomplished with occipitocervical arthrodesis with posterior arch resection. Predominant preoperative neurologic deficit according to Ranawat was grade II and postoperatively was grade I. CONCLUSIONS: The average age of patients in our series was discreetly lower in regard to what has been reported in the literature. Female predominance was in accordance with previous publications. Eight of 11 patients showed improvement as in other series. A higher impact was observed in patients between 30 and 64 years of age. The occupational activity with the highest frequency was homemaker, and the neurologic deficit according to Ranawat showed improvement in 72% of the patients.

Resultado en el tratamiento quirúrgico de la inestabilidad atlantoaxoidea / Results of the surgical treatment of atlantoaxial instability

Introducción: La inestabilidad de la columna cervical es el aumento en la movilidad más allá de los límites fisiológicos de una vértebra sobre otra en alguno de sus ejes, que condiciona síntomas en el paciente. Existen causas traumáticas, degenerativas, metabólicas y neoplásicas. Material y métodos: Se realizó estudio retrospectivo, longitudinal, observacional y descriptivo, de intervención deliberada, en pacientes con cirugía por inestabilidad atlantoaxoidea, de enero de 1993 a mayo de 2002, con un seguimiento mínimo de cinco años. Resultados: Se evaluaron 11 pacientes, con edades de 25 a 75 años, media de 56 años. El sexo predominante fue el femenino. La etiología fue iatrogénica en seis casos, cuatro por artritis reumatoide y uno postraumática. En todos se realizó fijación y artrodesis occipitocervical con resección del arco posterior. El déficit neurológico preoperatorio predominante según la escala de Ranawat fue grado II, y en el posoperatorio fue grado I. Conclusiones: La edad media de nuestra serie fue discretamente menor respecto a la indicada en la literatura; el sexo predominante correspondió a lo informado en la literatura. Existió mejoría en ocho de los 11 pacientes, como en otras series. La mayor incidencia se observó entre los 30 y 64 años. La actividad ocupacional con mayor frecuencia fue la del hogar. El déficit neurológico según la escala de Ranawat mejoró en 72 % de los pacientes.

BACKGROUND: Instability of the cervical spine is defined as an increase in flexibility farther than the physiological limits of one vertebra over another in some of its axes, conditioning symptoms for the patient. Traumatic, degenerative, metabolic and neoplastic causes have all been identified. METHODS: A retrospective, longitudinal, observational and descriptive study was carried out on patients surgically intervened specifically for atlantoaxial instability from January 1993 to May 2002, with a minimum 5-year follow-up. RESULTS: Eleven patients were evaluated. Ages ranged from 25 to 75 years (average age 56 years) with a female predominance. Etiology was iatrogenic in six cases, and there were four cases of rheumatoid arthritis and one case due to trauma. In all cases, fixation was accomplished with occipitocervical arthrodesis with posterior arch resection. Predominant preoperative neurologic deficit according to Ranawat was grade II and postoperatively was grade I. CONCLUSIONS: The average age of patients in our series was discreetly lower in regard to what has been reported in the literature. Female predominance was in accordance with previous publications. Eight of 11 patients showed improvement as in other series. A higher impact was observed in patients between 30 and 64 years of age. The occupational activity with the highest frequency was homemaker, and the neurologic deficit according to Ranawat showed improvement in 72% of the patients.

[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.