[Failed back surgery syndrome]. / Síndrome de columna multioperada.

BACKGROUND: Failed back surgery syndrome (FBSS) is well known and physicians often fear this outcome. Its definition is difficult to understand because it is multifactorial. However, we analyze its etiology in order to determine if it is from iatrogenic causes. This syndrome can be categorized as follows: mistaken diagnoses, transoperative error, technique error, poor application, poor indication. METHODS: We undertook a prospective, observational and lineal study in 20 patients, 313 surgeries and 4,500 consultations. Age and gender variables were analyzed, number of prior surgeries, and diagnosis prior to first surgery, as well as predominant symptoms for the last surgery, surgical time, and involved segment. Patients were evaluated with Oswestry preoperative scale and followed up for 2 years. RESULTS: There were 16 females and 4 males with an average age of 53.2 years. Eight patients had 1 prior surgery, 8 patients had 2 prior surgeries, 3 patients had 3 prior surgeries, and 1 patient had 4 prior surgeries. According to the Oswestry preoperative scale, 12 patients had scores higher than 60% and at 2-year follow-up, 11 patients had scores lower than 20%. Despite the persistent symptomatology and complications, in almost all patients the satisfaction index was 100%. According to the evaluation, the main cause was poor indication in three patients, poor indication + technique error in 10, and technique error in 7 patients. CONCLUSIONS: The most reported initial etiology was lumbar disc hernia with minimally invasive treatment with questionable surgical indication.

[Experience with prosthetic disc nucleus device in Mexico. Final report of a 4-year follow-up]. / Experiencia en México con prótesis discal de núcleo. Reporte final a 4 años de seguimiento.

BACKGROUND: Discal hernia is generally treated by discectomies that are mutilating and cause instability and low back pain in 50% of the patients. Partial arthroplasty is used in an attempt to avoid degeneration after a discectomy. METHODS: Nineteen patients from the INR (National Institute of Rehabilitation) were selected with extruded discal hernia. All inclusion criteria were met, with a minimal follow-up of 4 years. Evolution was evaluated with the Oswestry scale (OS) and x-ray studies. Statistical analysis was done with Student's t-test. RESULTS: Sixteen men and three women were included in the study, with an average age of 35.4 years. OS before surgery was 57.37% and improved to 22% (p < 0.001). The results obtained in the Prolo scale 4 years later were for the economy scale, p < 0.001 (Wilcoxon Z = 3.87) and for the functional scale, p < 0.001 (Wilcoxon Z = -3.94). The intervertebral space height (IS) before surgery was 6 and 8 mm, and 4 years later, in 12 patients it remained between 8 and 10 mm. The prosthesis had variations according to its initial placement in seven patients, and in all there was subsidence. In two cases migration surpassed the limits of the vertebral body without clinical repercussion. None of the patients required re-operation. CONCLUSIONS: Prosthetic disc nucleus device improved clinical conditions and x-rays of the patients using Oswestry, Prolo and intersomatic space height enhancement after 4 years of follow-up in 12/19 patients.

[Percutaneous biopsy evaluation in the diagnosis of thoracic and lumbar vertebral destruction syndrome]. / Evaluación de la biopsia percutánea en el diagnóstico del síndrome de destrucción vertebral tóracico y lumbar.

BACKGROUND: The vertebral destruction syndrome is defined as those pathologies affecting the integrity of the vertebral structure, modifying its normal architecture and resulting in neurological deficit. Correct diagnosis is essential to define appropriate treatment. Biopsy, in addition to histopathological study, is a vital element for definitive diagnosis. METHODS: We carried out a descriptive, deliberate interventional study in 20 patients with a diagnosis of vertebral destruction in whom a percutaneous transpendicular biopsy was done between January 2005 and July 2006. Variables analyzed were age, sex, affected segment, neurological condition, neurological deficit type, results of the biopsy and specific diagnosis. RESULTS: There was a predominance of males (55%). The lumbar spine was the most affected region in 80% of patients. Of the biopsies performed, 10% were reported as normal tissue, 20% with degenerative changes, 15% with inflammatory changes, 15% with primary tumoral lesion, 5% with chronic osteomyelitis, 10% with tuberculosis, 15% with tumoral metastasis and 10% necrotic devitalized bone tissue. Of these patients, 55% were treated nonsurgically, and the remaining 45% were treated surgically. No complications were reported. CONCLUSIONS: Percutaneous transpedicular biopsy has only 55% specificity in diagnosis and for that reason is a less useful diagnostic method in our setting for destructive lesion diagnosis from the vertebral body.

[Surgical treatment for scoliosis. Minimal evolution control at 5 years]. / Tratamiento quirúrgico de la escoliosis. Control de evolución mínimo de 5 años.

BACKGROUND: We undertook this study to determine the surgical treatments results performed often to correct scoliosis in the Spinal Surgery Service in the INR/Orthopedics (National Institute of Rehabilitation/Orthopedics), Mexico City. METHODS: We conducted a longitudinal, prospective, descriptive, and clinical study with a deliberated intervention controlled from a historical cohort. One hundred twenty patients with scoliosis were reviewed in whom surgery was performed during 1990-1999. For quantitative variables, pre- vs. postoperative measures were compared using non-parametric means with chi(2) or in this case with ANOVA by Kruskall-Wallis test. Differences are considered significant if p <0.05. RESULTS: Age average of patients was 12 years. There were 75 females and 45 males. There were 59 idiopathic scoliosis cases and 54 congenital scoliosis cases. Anterior approach was accomplished in 61 cases with posterior fixation. Posterior approach was used in 54 cases. There were 76 cases of Luque segmental instrumentation. Pre-operatively, scoliosis was ranked (18 to 110 grades) and postoperatively (5 to 90 grades) (p = 0.00001). There were 21 complications, 9 due to injuries or infection. In 76 patients, different fixation techniques were used, obtaining a correction average of 14.47 grades. Forty four patients were structured with bars, four distal screws, two compression screws, proximal hooks with sublaminar wire, and the angle was reduced on average 23.11 grades. CONCLUSIONS. Average reduction of scoliosis was higher with the modified Luque III instrumentation (p <0.045). There was no difference between etiology and preoperative angle.

[Aneurysmal bone cyst of the spine. Case report]. / Quiste óseo aneurismático de la columna vertebral. Reporte de un caso.

The aneurysmal bone cyst (ABC) is a fast-growing tumor of undefined neoplastic nature. It is occasionally an aggressive benign lesion whose treatment of choice is a complete resection, even though the risk of profuse transoperative bleeding exists. We present a female patient with thoracic spine deformity, with progressive paresthesias and muscle weakness of lower extremities that evolved to paralysis of both lower extremities and sphincter incontinence. Based on radiographic films, lytic lesions were identified at T7 to T9 vertebrae as well as medullary space invasion. In electrophysiologic tests, a complete somatosensorial pathway block was reported. Prior to resection of the neoplastic lesion and thoracolumbar stabilization, an incisional biopsy was performed. There was no postoperative medullary functional improvement. Morphological findings corresponded to an aneurysmal bone cyst at T8. This lesion is mainly located in the long bones and less frequently of the spine, where instability and medullary compression may occur. It is possible to confuse this neoplasia with other lesions. Hence, definite diagnosis with biopsy is necessary for determining an adequate therapeutic plan to eradicate recurrence risk or associated neurologic sequelae, as well as to gain proper stability at the involved vertebral segments.

[Stability effect of the suprajacent vertebrae after fixation in spondylolisthesis. Comparative study of two systems]. / Repercusión en la estabilidad del segmento suprayacente después de la fijación de la espondilolistesis. Estudio comparativo de dos sistemas.

BACKGROUND: This study was undertaken to evaluate vertebral stability after two different types of fusion fixation (rigid and semirigid) in spondylolisthesis. MATERIAL AND METHODS: Ambispective study of a dynamic cohort constituted by 42 patients that underwent surgery between 1990 and 2000 for a spondilolistesis treatment. According to the fixing type, they were divided into two follow-up groups: to group 1, plate INO (semirigid system) was placed + posterolateral fusion (PLF), 20 cases; to group 2, plate INO was installed + intersomatic screw + PLF, 22 cases. RESULTS: Both groups achieved better listhesis, reduced pain according to Oswestry and SF36 Index (p <0.05), and less intervertebral height was lost. Group 1 lost the least amount (-0.61 mm) of invertebral height if grades of presurgical listhesis were 1-2, and higher (-2.0 mm) if grades of presurgical listhesis were 3-4. Inversely, group 2 lost the least (0.50 mm) if grade of listhesis was 3 or 4, and higher (-1.25 mm) if grades of listhesis were 1-2. From 4 to 7 years, in group 2 there was altered bending of 5.8 degrees to 8.3 degrees (p = 0.05), a significant difference from group 1. Group 2 showed higher flexion grades (p = 0.01) at 4-7 years postoperatively and a significant reduction in EVA (p = 0.04) at more than 7 years. The remaining patients showed no significant differences between groups. But loss of intervertebral height was higher in group 2 (-1.18 mm) than group 1 (-0.75 mm). Plate INO + PLF favored flexibility and reduced loss of intervertebral height in grades 1-2 of presurgical listhesis, INO + screw + PLF showed reduced listhesis and decrease of height lost in grades 3-4 of presurgical listhesis. CONCLUSIONS: We recommended the use of INO + PLF in grades 1-2 of presurgical listhesis and INO + screw + PLF in grades 3-4 of listhesis presurgically.

Dynamic interspinous stabilization in lumbar discectomy: 4-year follow-up.

BACKGROUND: Semirigid posterior stabilization is an alternative, avoiding arthrodesis in operated segments. However, this results in the need for dynamic stabilization to allow a stable feature function. METHODS: We conducted a prospective longitudinal self-reported interventional study. We included 46 patients with dynamic Dallostype interspinous stabilization between 1997 and 2004. A 4-year follow-up analysis was performed using clinical and radiographic studies, preoperatively and 4 years later evaluating lumbar disability, pain, disc height, disc angle (neutral, flexion, and extension). Descriptive statistics were used along with Wilcoxon signed range test. Statistical significance was accepted when p < 0.05. RESULTS: Of 46 patients, 39 completed a 4-year follow-up. Included in the study were nine females and 30 males with an average age of 30.74 years. Affected levels were L4 and L5 (21 patients); L5/S1 (17 patients) and L3/L4 (one patient). An improvement was reported of 80.3% according to the Oswestry scale (p = 0.0001). Preoperative pain decreased 6.8 points VAS. Disc height decreased 0.1 mm on average without significance. Disc angle (neutral) increased 1.13° without statistical difference. For flexion the increase was 2.641° (p = 0.0002), and extension decreased 0.817° on average without statistical significance. Range of mobility decreased 3.416° (p = 0.004). CONCLUSIONS: Interspinous ligamentoplasty improves segmental stability, allowing mobility within normal ranges and preserving disc height at 4 years of follow-up, as well as offering greater dynamic stability. Successful clinical improvement was demonstrated.

[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.

[Vertebral destruction syndrome. Diagnostic evaluation systems]. / Síndrome de destrucción vertebral. Sistemas de evaluación en su diagnóstico.

BACKGROUND: Vertebral Destruction Syndrome (VDS) is a pathology of multiple etiologies causing structural alterations of the spine, producing deformity with neurological and mechanical alterations. In order to study VDS, a diagnostic process is carried out, sometimes with unexpected results. We undertook this study to validate the systematization of a series of studies to arrive at the diagnosis of VDS. METHODS: We included 105 patients in the study with diagnosis of VDS from January 1998 to December 2005, taking into consideration specificity, sensitivity and predictive value of each integrated study in order to determine its diagnostic value. RESULTS: The most frequent etiology was Pott's Disease (24 cases) followed by osteomyelitis (20 cases), metastasis (18 cases) and multiple myeloma and plasmacytoma (16 cases each). The higher sensitivity in Pott's Disease was obtained with bone scan and polymerase chain reaction (PCR); for multiple myeloma, computerized axial tomography (CAT) and bone scan; CAT and bone scan for infections; MRI for primary tumors; and MRI and bone scan for secondary tumors. CONCLUSIONS: To reduce false positives to 2% and to reduce the maximum number of false negatives, studies such as CAT, MRI, bone scan, PCR, ESR, C-reactive protein and determination of alkaline and acid phosphatase must be included in the VDS study protocol. Other studies have very low diagnostic sensitivity and specificity.

[Clinical and radiological follow-up of Nubac disc prosthesis. Preliminary report]. / Evaluación clínica y radiológica de la prótesis de núcleo discal Nubac. Informe preliminar.

BACKGROUND: Lumbar arthroplasty is an alternative to fusion for the treatment of degenerative disc disease. Replacement of the nucleus pulposus preserves the biomechanical properties in the annulus and plates, conserving lumbar motion. Our objective was to evaluate the feasibility and clinical and radiological findings at 3 months follow-up with the Nubac device. METHODS: Ten patients from the National Institute for Rehabilitation (INR, Mexico City) with degenerative disc disease were selected to participate in the study. They underwent discectomy with Nubac device with a follow-up period of 3 months. Evolution was evaluated with the VAS and Oswestry scales. RESULTS: Five men and five women were included in the study (average age 41.6 years). Surgical approach was anterolateral (4 patients), posterior (3 patients) and anterior (3 patients), VAS improved from 8.1 to 2.5 (p <0.05) and Oswestry Disability Index (ODI) improved from 58.2% to 24.2% (p <0.05). Disc height before surgery was 9.4 mm, and 3 months postoperatively was 12.5 mm with no complications, migration, or subsidence. CONCLUSIONS: Nubac prosthesis improved lumbar discogenic pain in a short time when evaluated using ODI and VAS scales. Disc height improved after a 3-month follow-up, but lumbar motion did not improve. No complications have been reported; however, a minimum follow-up of 4 years is needed to make a definite conclusion.

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.

Síndrome de destrucción vertebral: sistemas de evaluación en su diagnóstico / Vertebral destruction syndrome: diagnostic evaluation systems

BACKGROUND: Vertebral Destruction Syndrome (VDS) is a pathology of multiple etiologies causing structural alterations of the spine, producing deformity with neurological and mechanical alterations. In order to study VDS, a diagnostic process is carried out, sometimes with unexpected results. We undertook this study to validate the systematization of a series of studies to arrive at the diagnosis of VDS. METHODS: We included 105 patients in the study with diagnosis of VDS from January 1998 to December 2005, taking into consideration specificity, sensitivity and predictive value of each integrated study in order to determine its diagnostic value. RESULTS: The most frequent etiology was Pott's Disease (24 cases) followed by osteomyelitis (20 cases), metastasis (18 cases) and multiple myeloma and plasmacytoma (16 cases each). The higher sensitivity in Pott's Disease was obtained with bone scan and polymerase chain reaction (PCR); for multiple myeloma, computerized axial tomography (CAT) and bone scan; CAT and bone scan for infections; MRI for primary tumors; and MRI and bone scan for secondary tumors. CONCLUSIONS: To reduce false positives to 2% and to reduce the maximum number of false negatives, studies such as CAT, MRI, bone scan, PCR, ESR, C-reactive protein and determination of alkaline and acid phosphatase must be included in the VDS study protocol. Other studies have very low diagnostic sensitivity and specificity.

Evaluación clínica y radiológica de la prótesis de núcleo discal Nubac: informe preliminar / Clinical and radiological follow-up of Nubac disc prosthesis: preliminary report

BACKGROUND: Lumbar arthroplasty is an alternative to fusion for the treatment of degenerative disc disease. Replacement of the nucleus pulposus preserves the biomechanical properties in the annulus and plates, conserving lumbar motion. Our objective was to evaluate the feasibility and clinical and radiological findings at 3 months follow-up with the Nubac device. METHODS: Ten patients from the National Institute for Rehabilitation (INR, Mexico City) with degenerative disc disease were selected to participate in the study. They underwent discectomy with Nubac device with a follow-up period of 3 months. Evolution was evaluated with the VAS and Oswestry scales. RESULTS: Five men and five women were included in the study (average age 41.6 years). Surgical approach was anterolateral (4 patients), posterior (3 patients) and anterior (3 patients), VAS improved from 8.1 to 2.5 (p <0.05) and Oswestry Disability Index (ODI) improved from 58.2% to 24.2% (p <0.05). Disc height before surgery was 9.4 mm, and 3 months postoperatively was 12.5 mm with no complications, migration, or subsidence. CONCLUSIONS: Nubac prosthesis improved lumbar discogenic pain in a short time when evaluated using ODI and VAS scales. Disc height improved after a 3-month follow-up, but lumbar motion did not improve. No complications have been reported; however, a minimum follow-up of 4 years is needed to make a definite conclusion.

Evaluación de la biopsia percutánea en el diagnóstico del síndrome de destrucción vertebral tóracico y lumbar / Percutaneous biopsy evaluation in the diagnosis of thoracic and lumbar vertebral destruction syndrome

BACKGROUND: The vertebral destruction syndrome is defined as those pathologies affecting the integrity of the vertebral structure, modifying its normal architecture and resulting in neurological deficit. Correct diagnosis is essential to define appropriate treatment. Biopsy, in addition to histopathological study, is a vital element for definitive diagnosis. METHODS: We carried out a descriptive, deliberate interventional study in 20 patients with a diagnosis of vertebral destruction in whom a percutaneous transpendicular biopsy was done between January 2005 and July 2006. Variables analyzed were age, sex, affected segment, neurological condition, neurological deficit type, results of the biopsy and specific diagnosis. RESULTS: There was a predominance of males (55%). The lumbar spine was the most affected region in 80% of patients. Of the biopsies performed, 10% were reported as normal tissue, 20% with degenerative changes, 15% with inflammatory changes, 15% with primary tumoral lesion, 5% with chronic osteomyelitis, 10% with tuberculosis, 15% with tumoral metastasis and 10% necrotic devitalized bone tissue. Of these patients, 55% were treated nonsurgically, and the remaining 45% were treated surgically. No complications were reported. CONCLUSIONS: Percutaneous transpedicular biopsy has only 55% specificity in diagnosis and for that reason is a less useful diagnostic method in our setting for destructive lesion diagnosis from the vertebral body.

Quiste óseo aneurismático de la columna vertebral: reporte de un caso / Aneurysmal bone cyst of the spine: case report

El quiste óseo aneurismático es un tumor de naturaleza neoplásica indefinida, de comportamiento benigno, crecimiento rápido y ocasionalmente de comportamiento agresivo, cuyo tratamiento de elección es la resección completa, aunque existe el riesgo de sangrado transquirúrgico excesivo. Se presenta el caso de una paciente con deformidad en columna torácica, con parestesias y debilidad muscular progresivas en extremidades inferiores, que evolucionó hasta la parálisis de dichas extremidades e incontinencia de ambos esfínteres. Mediante estudios de gabinete se localizaron lesiones líticas en cuerpos vetebrales T7 a T9 e invasión a conducto raquídeo. Los estudios electrofisiológicos identificaron bloqueo completo de la vía somatosensorial. Previa biopsia incisional, se realizó resección de la lesión y estabilización de la columna toracolumbar. La paciente evolucionó sin mejoría de la función medular. Los hallazgos morfológicos correspondieron a quiste óseo aneurismático en T8. Esta lesión se localiza principalmente en huesos largos y con mucho menor frecuencia en la columna vertebral, donde puede provocar inestabilidad y compresión de la médula espinal. Es posible confundirla con otras neoplasias, por lo que el diagnóstico definitivo mediante biopsia es imprescindible a fin de establecer el plan terapéutico adecuado, que elimine el riesgo de recurrencia o secuelas neurológicas asociadas, y lograr la estabilidad adecuada de los segmentos vertebrales afectados.

The aneurysmal bone cyst (ABC) is a fast-growing tumor of undefined neoplastic nature. It is occasionally an aggressive benign lesion whose treatment of choice is a complete resection, even though the risk of profuse transoperative bleeding exists. We present a female patient with thoracic spine deformity, with progressive paresthesias and muscle weakness of lower extremities that evolved to paralysis of both lower extremities and sphincter incontinence. Based on radiographic films, lytic lesions were identified at T7 to T9 vertebrae as well as medullary space invasion. In electrophysiologic tests, a complete somatosensorial pathway block was reported. Prior to resection of the neoplastic lesion and thoracolumbar stabilization, an incisional biopsy was performed. There was no postoperative medullary functional improvement. Morphological findings corresponded to an aneurysmal bone cyst at T8. This lesion is mainly located in the long bones and less frequently of the spine, where instability and medullary compression may occur. It is possible to confuse this neoplasia with other lesions. Hence, definite diagnosis with biopsy is necessary for determining an adequate therapeutic plan to eradicate recurrence risk or associated neurologic sequelae, as well as to gain proper stability at the involved vertebral segments.

Tratamiento de la espondilolistesis con placas y tornillos transpediculares tipo INO / Treatment of spondylolisthesis by trans-pedicular INO screw-plating

El uso de un sistema semirrígido o rígido de fijación con placas y tornillos transpediculares proporciona una sujeción inmediata, no requiere la presencia de láminas para la fijación y no invade el canal medular. En el INO, se ha desarrollado un sistema transpedicular que cumple estos requisitos; el propósito de este trabajo es conocer y evaluar los resultados y complicaciones del uso de las placas y tornillos INO, en la columna vertebral de las regiones torácicas, lumbar y sacra. Se presentaron 19 casos iniciales. De acuerdo con la escala de valoración de Thalgott para consolidación, dolor y compliciones se obtuvo un buen resultado en 82.4 por ciento de los casos después de un año

Diagnóstico y tratamiento del mal de Pott: experiencia del Instituto Nacional de Ortopedia / Diaganosis and treatment of Pott's disease: experience of National Orthopedic Institute of Mexico

Debido a los efectos tardíos de la tuberculosis vertebral y a su frecuencia en países en vías de desarrollo, se realizó un estudio retrospectivo en el Servicio de Cirugía de Columna Vertebral del Instituto Nacional de Ortopedia, de 1987 a 1991, para establecer un protocolo de estudio y seguimiento. Se revisaron los expedientes clínico-radiogáficos de 43 pacientes, incluyéndose sólo 19 expedientes completos. Se evaluó: el tiempo de evolucipon para su diagnóstico, el número de vértebras afectadas, daño neurológico (clasificación de Frankel), tipo de imagen radiográfica, grado de pérdida de corrección, tiempo de hospitalización, tipo de injerto óseo utilizando y tiempo de integración, y complicaciones. Se encontró que el tiempo promedio de evolución fue de 7.4 años; el promedio de vértebras afectadas fue de 2.7; sólo dos pacientes tuvieron mejoría en la alteración neurológica, 17 permanecieron igual pero con una función adecuada. El tipo de imagen radiográfica fue de destrucción geográfica en 15 casos. El promedio de pérdida de corrección fue de 4.4 grados al finalizar el tratamiento; y el tiempo promedio de hospitalización fue de 100 días. El tipo de injerto óseo más utilizado fue el de costilla en ocho casos, con un promedio de integración de 9.1 meses. Las complicaciones fueron: un caso sin integración del injerto, dos colapsos del injerto óseo, uno con artritis de la rodilla, un absceso de psoas ilíaco, una radiculopatía, un paciente con protrusión de la barra, una dehiscencia de la herida y dos recidivas de infección corroboradas con BAAR después del tratamiento antifímico.