Biomedical subjects

Tamás de Jonge

Publications and source records attributed to Tamás de Jonge.

5 recordsLinked to original sources

PubMed2005

Late-onset spinal deformities in children treated by laminectomy and radiation therapy for malignant tumours.

This is a retrospective study of 76 children who had had malignant tumours treated with laminectomy or laminoplasty and/or radiation therapy affecting the spine. Spinal tumours in children are extremely rare. However, their treatment can result in progressive spinal deformity. Radiation therapy affecting the growing spine can lead to asymmetric vertebral growth, causing kyphosis and/or scoliosis. These spinal deformities pose one of the most challenging problems for the spine surgeon. The aim of this article is to describe late-onset post-laminectomy/post-radiation spinal deformities and to evaluate the results of their treatment. Seventy-six children, with a mean age of 4 years and 7 months (range, 2 months to 16 years), underwent surgical removal of malignant tumours, between 1961 and 1995. Sixty-seven of them developed post-laminectomy/post-radiation spinal deformity. Conservative treatment consisted of bracing and corrective plaster casts. In 46 cases the deformity was treated surgically. A distraction plaster cast was used as preoperative preparation in the more severe and rigid curves, with or without neurological impairment. Surgery consisted of combined anterior and posterior fusion in 39 cases and posterior fusion in seven cases. Posterior instrumentation was used in 38 cases. The mean follow-up period was 6 years and 7 months (range, 9 months to 20 years and 2 months). Nine children did not develop deformity following the primary tumour treatment. One of them underwent laminectomy with posterolateral fusion and eight had laminoplasty combined with external immobilisation. Forty-six children developed iatrogenic kyphosis and underwent surgical correction from a mean of 75 degrees pre-correction to a mean of 32 degrees . The mean scoliotic angle correction was 66 degrees preoperatively to 34 degrees postoperatively. At follow-up, the mean correction loss was 7 degrees in the sagittal plane and 5 degrees in the coronal plane. Preoperative distraction plaster cast treatment resulted in a correction of 39% in kyphosis and of 58% in scoliosis, and in a partial or complete recovery of neurological deficits in all but one patient. In severe and rigid curves that develop following treatment of paediatric spinal tumours, preoperative application of a distraction plaster cast can reduce deformity and facilitate surgical correction. Furthermore, in the case of pure bony compression of the spinal cord due to the apical vertebra of the deformity, treatment with the distraction plaster can result in recovery from the neurological impairment. The prevention of post-laminectomy/post-radiation spine deformities is emphasised. Rigid external immobilisation for a period of 4 months in the cervical spine and of 6 months in the thoracic spine is recommended after both laminoplasty and laminectomy with posterolateral fusion.

Adolescent↗

PubMed2002

Sagittal plane correction in idiopathic scoliosis.

STUDY DESIGN: Patients with idiopathic scoliosis who had undergone posterior fusion by means of posterior multisegmented hook instrumentation were studied retrospectively. OBJECTIVES: To present the changes in projected thoracic hypokyphosis and the behavior of lumbar lordosis within and below the fusion. SUMMARY OF BACKGROUND DATA: Scoliosis is a three-dimensional deformity of the spine. The idiopathic cases usually exhibit a flattening of the sagittal curves, which had further deteriorated when the Harrington technique was used. The consequences included the flat back, angular increase of the lumbar lordosis below the fusion, and low back pain. Previous studies showed no or only moderate correction of thoracic hypokyphosis when using Cotrel-Dubousset instrumentation or its modifications were used. Harrington rod systems resulted in decreased lumbar lordosis in the fusion area and increased lordosis below the fusion. No background data were found concerning the effects of multisegmented hook instrumentation on the lumbar spine within and below the fusion. METHODS: For this study, 306 patients with idiopathic scoliosis who had undergone posterior spinal fusion with multisegmented hook systems using the derotation maneuver were analyzed after a mean follow-up period of 5 years and 4 months. The coronal plane curvature, the sagittal plane projection of the thoracic kyphosis, and the lumbar lordosis within and below the fusion were evaluated. RESULTS: The average coronal plane correction was 67.1%. Analysis of the sagittal contours demonstrated that the preoperative thoracic hypokyphosis (less than 20 degrees between T4 and T12) increased by an average of 12 degrees, and that 55.1% of hypokyphotic backs were corrected to the normal range (20 degrees to 40 degrees ). In patients with frank lordosis (kyphosis less than 10 degrees ), the degree of correction was higher (average, 16 degrees ), but complete correction was achieved in only 38.5% of the cases. In patients with mild lordosis (kyphosis between 10 degrees and 20 degrees ), the average correction was 8 degrees, and 71.3% of the patients were in the normal range after surgery. The normal preoperative thoracic kyphosis was preserved in 81.3% of the cases. In the lumbar area, the Cotrel-Dubousset instrumentation was capable of correcting the preoperative hypolordosis (less than -20 degrees between L1 and L5) in 94.4% of the cases. The normal preoperative lordosis (-20 degrees to -60 degrees ) was preserved in 97.9% of the cases. The hyperlordosis was corrected in all cases. Analysis of the data in terms of lower fusion limit showed that the lower the caudal hook, the greater the increase in the segmental lordosis within the fusion, without any increase distal to the fusion. No segmental hyperlordosis was observed below the fusion. CONCLUSIONS: The Cotrel-Dubousset technique ensures considerable sagittal correction of the spine. In the course of scoliosis correction, it is possible to preserve the normal preoperative sagittal profile of the spine, to correct the slightly flattened thoracic kyphosis, to increase materially the kyphosis of the frankly hypokyphotic spine, to preserve or restore normal lumbar lordosis in a considerable percentage of the cases, to avoid angular segmental hyperlordosis at the level of the first disc below the fusion, and to avoid retrolisthesis of the last fused vertebra.

Adolescent↗

PubMed2002

Hyperrotatory paradoxic kyphosis.

STUDY DESIGN: A retrospective radiographic evaluation of 32 patients with hyperrotatory scoliosis accompanied by paradoxic hyperkyphosis, who were treated with posterior multilevel hook instrumentation. OBJECTIVES: To give a three-dimensional analysis of this particular deformity and to evaluate the coronal, sagittal, and horizontal plane corrections in these specific curves. SUMMARY OF BACKGROUND DATA: Lordoscoliosis with a severe rotational component produces paradoxic kyphosis in the sagittal plane. A vertebral derotational maneuver is essential to restore the normal sagittal alignment. METHODS: Thirty-two patients were treated with posterior multilevel hook instrumentation. Nine patients had previously undergone anterior release and fusion. The derotational maneuver could be accomplished in 21 cases. The coronal Cobb angle and the extents of apical vertebral rotation, sagittal hyperkyphosis, upper and lower compensatory lordosis, and sagittal trunk balance were measured after an average follow-up period of 5 years and 9 months. RESULTS: The mean coronal deformity decreased from 89.9 degrees before surgery to 40.7 degrees. The mean preoperative hyperkyphosis was 70.9 degrees in the thoracic spine, 45.9 degrees in the thoracolumbar spine, and 55 degrees in the lumbar region. These values were reduced to 39.7 degrees, 6.8 degrees, and -15 degrees, respectively. The lateral spinal balance changed from -21.3 mm to -8.5 mm. The average rotational correction measured by the method of Jackson was 51% before surgery and 39% after surgery (correction: 23.5%). There was a positive correlation between the preoperative kyphosis angle and the apical rotation (r = 0.58) and between the decrease of kyphosis and the correction of the rotation (r = 0.67) in cases when the derotational maneuver could be accomplished. CONCLUSIONS: If the apex of the scoliosis and the kyphosis are on the same level, the vertebral hyperrotation is responsible for the sagittal malalignment. Satisfactory results can be achieved with posterior multilevel hook instrumentation.

Adolescent↗

PubMed2002

Surgical correction of the late consequences of posttraumatic spinal disorders.

This retrospective study was performed to evaluate the results of the treatment of late posttraumatic spinal disorders. Five patients with thoracolumbar kyphosis, two with paralytic kyphoscoliosis and two with posttraumatic instability with pain but without neurologic symptoms and apparent deformity, were treated surgically. Various surgical procedures were performed depending on the pathologic conditions. Corrections achieved in the sagittal and frontal planes were analyzed on radiographs after a mean follow-up of 4.4 years. In cases of angular kyphosis, the deformity measured 48.8 degrees on average before operation and 9.3 degrees afterward. Preoperative neurologic impairments were improved in all cases. Patients with paralytic scoliosis benefited from an average surgical correction of 68%. The restoration of truncal balance helped the patients to regain a normal sitting posture. Pain was reduced in all patients after surgery, as it was in patients with low back pain caused by posttraumatic instability without deformity. The results of the current study emphasize the importance of adequate management of spinal injuries to prevent late spinal sequelae.

Adolescent↗

PubMed2002

Surgical treatment of spinal deformities associated with neurofibromatosis type 1. Report of 12 cases.

OBJECT: In 10 to 50% of cases with neurofibromatosis, skeletal disorders are present, mainly as various deformities of the spine. These deformities can be divided into dystrophic and nondystrophic groups depending on the absence or presence of bone dystrophy. The nondystrophic curves are highly similar to those in idiopathic scoliosis, whereas the dystrophic curves are manifested early and, by progressing inexorably, may lead to neurological symptoms. In this article the authors report on a series of 12 patients (11 with dystrophic and one with nondystrophic deformities) who underwent surgical treatment. METHODS: In the case with a nondystrophic curve, posterolateral instrumentation-assisted fusion was performed. A curvature correction of 70% was achieved in the frontal plane, and at the 2-year follow-up examination neither bone dysplasia nor pseudarthrosis was observed. In the cases with dystrophic curves, preoperative traction for 3 weeks was applied; anterior surgical release was then performed, as was two-stage posterior instrumentation-assisted fusion. In the cases of thoracic kyphoscoliosis in which this treatment protocol was performed, the mean scoliosis correction was 66%, whereas the mean decrease in kyphotic angle was 34.5 degrees. In the cases with thoracolumbar and lumbar curves, the mean correction in the frontal plane was 69.8 degrees, whereas the mean preoperative lumbar kyphosis of 42 degrees was corrected to a mean lordotic angle of 23 degrees. Postoperatively, no hook dislocation was detected. A neurological complication was observed in one case. CONCLUSIONS: The surgical treatment of dystrophic curves always included 360 degrees fusion and the use of a tibial corticocancellous graft, which must be placed on the concave side of the curve in the frontal plane, the graft thereby providing biomechanical support.

Adolescent↗