摘要:

Study Design.A randomized, prospective and controlled animal study.Objective.To evaluate lumbar spinal fusion using recombinant human bone morphogenetic protein 2 in a canine model.Summary of Background Data.Spinal fusion using autogenous bone grafting is associated with donor site morbidity and a nonunion rate of 5% to 35%. The use of recombinant human bone morphogenetic protein 2 as a bone graft substitute would eliminate donor site morbidity and perhaps augment the rate of successful fusion.Methods.Mature beagles underwent bilateral paraspinal exposure at L4–L5, followed by transverse process decortication and randomization into one of six groups using differing doses of recombinant human bone morphogenetic protein 2 implanted using either a Type I collagen carrier or a polylactic acid carrier. Two control groups were used: one group without recombinant human bone morphogenetic protein 2 and another group using autogenous rib graft alone.Results.Groups treated with recombinant human bone morphogenetic protein 2 demonstrated complete fusion in all animals. Animals treated with collagen carrier alone (no recombinant human bone morphogenetic protein 2) demonstrated complete absence of fusion. Successful fusion occurred in one of three canines in the autogenous bone graft group. Fusion masses in the recombinant human bone morphogenetic protein 2 treatment groups were significantly larger in size at 3 months than in the autogenous bone graft group. The collagen carrier was more biocompatible and biodegradable because residual polylactic acid carrier was seen with adjacent multinucleated giant cells. There was no evidence of spinal canal or nerve root encroachment in the recombinant human bone morphogenetic protein 2 treatment groups.Conclusions.The use of recombinant human bone morphogenetic protein 2 implanted using a Type I collagen carrier resulted in 100% fusion without adverse effects.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.Herniated tissue was studied by immunohistochemistry in eight patients with lumbar disc herniation. The results were compared with those of control subjects.Objective.To assess the presence and distribution of possible antigen-antibody complexes in herniated disc tissue.Summary of Background Data.It has been suggested that the nucleus pulposus may be recognized as a foreign-body by the immune system and that this will lead to secondary nerve root disturbance. Such immunologic events should be initiated by binding of antibodies to a specific antigen in the disc tissue. However, the presence of antigen-antibody complexes in the herniated disc tissue has not been assessed.Methods.Amplification of the peroxidase reaction produced in avidin-biotin-peroxidase complex immunostaining by diaminobenzidine was used to visualize antigen-antibody complexes in the herniated tissue. The authors used herniated tissue from eight patients with lumbar disc herniation and nucleus pulposus from five control subjects with nonlumbar disc herniation. Thin paraffin sections, prefixed in 4% paraformaldehyde, were incubated with anti-human IgG antibody to allow visualization of antigen-antibody complexes in the specimens.Results.A brown deposit, indicating antigen-antibody complexes, could be observed in the pericellular capsule in herniated disc tissue but not in control discs or in the residual discs of the herniation patients.Conclusion.Antigen-antibody complexes seem to be commonly present in herniated disc tissue, but not in healthy discs. However, the pathophysiologic and clinical significance of this observation has to be elucidated further.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A radiographic examination of pinealectomized rats to observe the development of scoliosis and halt the condition by administration of melatonin.Objectives.To discover whether pinealectomy has the same effect in mammals as shown in the chicken, and to determine whether the bipedal condition is important for development of scoliosis.Summary of Background Data.Pinealectomizing chickens shortly after hatching consistently resulted in scoliosis closely resembling human idiopathic scoliosis. It has not been determined whether this phenomenon is restricted solely to chickens, or if this experimental model is applicable to other animals, especially those more closely related to humans.Methods.A sham operation in five bipedal rats served as the control in this study. Pinealectomy was performed in 10 quadrupedal rats, pinealectomy in 20 bipedal rats, and pinealectomy with implantation of melatonin pellet in 10 bipedal rats. Spinal radiographs were used to measure the degree of scoliosis at 3 months after surgery.Results.Scoliosis developed only in pinealectomized bipedal rats and not in quadrupedal rats. It developed in none of the sham operation group and in only 1 of 10 pinealectomized bipedal rats with melatonin treatment.Conclusions.Melatonin deficiency secondary to pinealectomy alone does not produce scoliosis if the quadrupedal condition is maintained. The bipedal condition, such as that in chickens or humans, plays an important role in the development of scoliosis. The findings suggest a critical influence of a postural mechanism for the development of scoliosis.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.An evaluation of cervical kyphosis in diastrophic dysplasia from newborn to adult life.Objectives.To discover the prevalence and natural history of cervical kyphosis in diastrophic dysplasia.Summary of Background Data.Typical findings in this rare skeletal dysplasia are short-limbed short stature, multiple joint contractures, early degeneration of joints, and spinal deformities such as cervical kyphosis, scoliosis, and exaggerated lumbar lordosis. In diastrophic dysplasia, spontaneous resolution of cervical kyphosis has been reported, but so have severe forms causing medullar compression leading to quadriplegia and death. The prevalence and clinical outcome of the kyphosis are not known.Methods.The radiographic natural history of the cervical spine was studied in 120 patients. They varied in age from newborns to 63-year-olds. The average follow-up time in 26 living patients with cervical kyphosis was 10.0 years.Results.Midcervical kyphosis was noted in 29 patients (24%) in their first radiograph. In 25 patients, the first radiographs were taken before the age of 18 months, and 24 of these patients (96%) had cervical kyphosis. The most severe case was that of a 32-year-old patient with a 165° kyphosis. In the 24 patients, the kyphosis resolved spontaneously at an average age of 7.1 years. Three patients with a severe kyphosis died; one patient is alive. One patient, a 4-year-old child, has mild resolving deformity.Conclusions.Cervical kyphosis in diastrophic dysplasia usually is shown at the time of birth. It resolves spontaneously during growth and seldom needs treatment. Careful follow-up study and treatment, if necessary, are important tools for avoiding the neurologic problems and fatal outcome.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.In 100 consecutive patients who underwent surgery because of soft cervical disc herniation, the sagittal and transverse diameters, the area of the bony cervical spinal canal, the sagittal diameter of the hernia, and the minimal bony intervertebral foramen diameter were measured by computed tomography. The data were compared with measurements from a control group of 35 matched healthy individuals.Objectives.To evaluate the relation between the severity of concurrent neurologic symptoms and the sagittal and transverse diameters, the cross-sectional area of the bony spinal canal, the sagittal diameter of the hernia, and diameter of the minimal bony intervertebral foramen in patients with soft cervical disc herniation.Summary of Background Data.Traumatic injury and spondylotic changes have a far greater impact on the spinal cord and nerve roots if the sagittal diameter of the bony cervical spinal canal is small. However, in the case of soft cervical disc herniation, no computer tomographic measurements are available for sagittal and transverse diameters, cross-sectional area of the bony spinal canal, sagittal diameter of the hernia, and diameter of the minimal bony intervertebral foramen in relation to the severity of concurrent neurologic symptoms.Methods.Computed tomography was used to measure sagittal and transverse diameters, cross-sectional area of the bony cervical spinal canal, sagittal diameter of the hernia, and diameter of the minimal bony intervertebral foramen in 100 patients with symptomatic monosegmental cervical soft disc herniation. All patients had undergone an anterior discectomy with removal of the hernia and subsequent interbody fusion using an autologous bone graft taken from the iliac crest.Results.A mean sagittal diameter of the bony cervical spinal canal of 12.9 mm was found, indicating a certain degree of developmental stenosis. Patients with motor disturbances had a significantly smaller sagittal diameter of the bony spinal canal than did patients without motor disturbances. There was a linear correlation between the sagittal diameter of the bony cervical spinal canal and that of the hernia. The sagittal diameter, the area of the bony spinal canal, and diameter of the minimal bony intervertebral foramen were significantly smaller in patients with soft cervical disc herniation than in the control group.Conclusions.Results from this study strongly suggest that the degree and severity of neurologic symptoms accompanying cervical soft disc herniation are inversely related to the sagittal diameter and the area of the bonycervical spinal canal. The latter area is reduced in cases of developmental stenosis or because of soft disc herniation. Moreover, patients with soft cervical disc herniation have a significantly smaller sagittal diameter of the bony spinal canal, a significantly smaller minimal bony intervertebral foramen diameter, and a significantly smaller cross-sectional area of the bony cervical canal than do healthy matched individuals.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.The contact pressure between the nerve root and lumbar disc herniation was measured and compared with clinical features.Objective.To assess levels of actual compression to the nerve root in clinical cases.Summary of Background Data.Actual levels of pressure to the nerve root of lumbar disc herniation in clinical cases is unknown.Methods.The study was performed on 34 patients who had lumbar disc herniation. All of them had been treated by open discectomy. After laminotomy, nerve root pressure was measured by inserting a transducer between the nerve root and the disc herniation. The magnitude of pressure was compared with clinical features.Results.Nerve root pressures before discectomy were varied from 7 mm Hg to 256 mm Hg (mean, 53 mm Hg). After discectomy, the contact pressure was 0 mm Hg in all cases. There were no significant correlations between the magnitude of nerve root pressure and limits to the degree of straight leg raising, duration of symptoms, and age of the patients. However, the magnitude of the pressure in patients with neurologic deficits and trunk list was significantly higher than in the absence of these findings.Conclusions.The contact pressure exerted by lumbar disc herniation on the nerve roots was recorded during surgical intervention, and the mean pressure was 53 mm Hg. The magnitude of nerve root pressure was not correlated with the degree of straight leg raising, but with the severity of neurologic deficits.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A retrospective analysis of radiographic reports on 161 consecutive patients with idiopathic scoliosis at the authors’ institution.Objectives.To compare various radiographic findings that directly affect surgical decision-making and the evaluation of postsurgical outcomes to determine the usefulness of information gathered from radiologists’ multiple duplicate reading of films.Summary of Background Data.To the authors’ knowledge, there are no previous studies on the readings of scoliosis films by radiologists and surgeons.Methods.The patient pool was drawn from the private practices of two board-certified orthopaedic surgeons. Each set of radiographs was read by one of seven board-certified radiologists and by one of the two surgeons. The two reports of each radiograph were compared. The factors included in the reports were scoliosis deformity, scoliosis type, curve progression, curve magnitude, levels of the curve, kyphosis, lordosis, the presence of instrumentation, and the presence of a fusion.Results.The radiologists and orthopedic surgeons mentioned the presence of scoliosis in 95% and 99.4% of their reports, respectively. The type of scoliosis was mentioned in 5% of reports by radiologists and in 99.4% by orthopedists. Progression of the curve was documented in 16.7% of the radiologists’ reports and in 98.4% of orthopedists’ reports. The magnitude of the curve was stated in 12.6% of the radiologists’ reports, compared with 98.1% of the orthopaedists’ reports. The levels of the curve were documented in 10.6% and 95.6% of reports by the radiologists and orthopedists, respectively. Radiologists mentioned kyphosis and lordosis in 28% and 26.5% of reports, respectively. These same two entities were mentioned in 98.2% and 79.4% of reports by the orthopedists. Finally, the radiologists noted the presence of instrumentation and of a fusion in 77.8% and 68.3% of reports, respectively. Orthopedists mentioned these same two entities in 84.4% and 100% of reports, respectively. In the radiologists’ reports on the presence of instrumentation, 20% were mislabeled or improperly identified. Seven percent of the fusions documented by the radiologists were incorrect because they were recorded before biologic fusion could have taken place. In all these categories, the radiologists provided information in excess of the orthopedic reports a total of 1.9% of the time. Of this 1.9% additional information, 36.8% was incorrectlyread or mislabeled. The other 63.2% of the additional information (1.9% of the total) did not elucidate anythingof real clinical significance that was missed by the orthopedic surgeons (e. g.,a tumor in the lung).Conclusions.These findings show that the attending orthopedic spine surgeons gained little useful information from the radiologists’ multiple duplicate reading of films.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A prospective and controlled comparative study of two instrumentation techniques used for the correction of adolescent idiopathic scoliosis.Objective.To measure the three-dimensional intraoperative correction obtained with a rotation maneuver as compared with that obtained with a translation maneuver of the first instrumentation rod inserted to determine the difference, if any, in the two techniques for achieving three-dimensional correction.Summary of Background Data.Adequate three-dimensional correction of scoliotic deformities has been reported with the Cotrel-Dubousset instrumentation using the rod-rotation maneuver. More recently, however, authors of studies with newer instrumentation systems have claimed that better correction can be obtained using a translation technique. So far, no report has clearly demonstrated the three-dimensional changes obtained with this more recent instrumentation technique.Methods.The changes in position of thoracic and lumbar vertebrae exposed during surgery were documented using a three-dimensional magnetic digitizer in 70 adolescents with idiopathic scoliosis undergoing correction by a posterior approach. Vertebral positions were measured intraoperatively before and after the surgical maneuver in 39 patients with the Cotrel-Dubousset instrumentation (rod rotation) and in 31 patients with the Colorado instrumentation (translation).Results.In both groups, adequate three-dimensional correction of the scoliotic deformities was documented, with significant changes in the frontal and sagittal planes and in the orientation of the plane of maximum deformity for thoracic and lumbar curves. On the other hand, no significant differences were documented between the two procedures except in the frontal plane where a tendency for greater correction was observed for thoracic curves with the translation technique.Conclusions.The two instrumentation techniques are equally able to achieve a comparable and effective three-dimensional correction of the scoliotic deformities. The use of either a rotation maneuver or a translation technique during surgery does not result in any significant measurable difference in three-dimensional correction.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A study using near-infrared light spectroscopy to measure recovery from exercise-induced desaturation in the paraspinal muscles of patients with idiopathic scoliosis.Objectives.To measure oxygenation of the paraspinal muscles and obtain differences between the convex and concave sides.Summary of Background Data.Authors of previous studies have reported that some patients experience pain on the convex side of the paraspinal muscles. The muscles on the convex side are more stretched and stressed than those on the concave side. The current authors investigated the degree of stress by measuring oxygenation and blood volume changes.Methods.Paraspinal muscle spectral properties at L3 were investigated using near-infrared light spectroscopy. Thirty-six patients (8 men and 28 women) underwent this procedure. To assess a level of peripheral adaptations to exercise, the half-time of Oxyhemoglobin/Myoglobin recovery was measured, which indicates the recovery from energy deficit after exercise.Results.The average half-time recovery on the convex side was 3.38 seconds (range, 1.5–5.5 seconds), whereas that on the concave side was 1.51 seconds (range, 0.7–4.0 seconds). The average difference between the convex side and the concave side was 1.87 seconds (range, 0.9–3.5 seconds).Conclusions.Half-time recovery on the convex side in the patients with idiopathic scoliosis was slower than that in healthy adults (P< 0.05) . Half-time recovery on the concave side in such patients was faster than that on the convex side (P< 0.01). The authors consider half-time recovery an indication of back muscle stress.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.Neurogenic mixed evoked potentials were recorded after thoracoscopic spinal cord stimulation in patients undergoing video-assisted spine surgery.Objective.To demonstrate the feasibility and value of thoracoscopic spinal cord monitoring.Summary of Background Data.Video-assisted thoracic surgery recently has been proposed as a new technique for thoracic spine surgery. It can be used for anterior spinal release of patients with severe spinal deformities and for thoracic hernia removal.Methods.Five patients undergoing video-assisted thoracic surgery for spinal fusion were studied. Neurogenic mixed evoked potentials were elicited by electrodes seated into intervertebral discs through thoracoscopy and recorded from peripheral nerves of the lower limbs. Moreover, the study included the case of a patient with a thoracic hernia who underwent video-assisted thoracic surgery with combined thoracoscopic neurogenic mixed evoked potential and standard somatosensory evoked potential monitoring.Results.Neurogenic mixed evoked potentials were recorded consistently after spinal cord stimulation in all patients. For the patient with a thoracic hernia, neurogenic mixed evoked potentials suddenly disappeared, whereas somatosensory evoked potentials were not significantly modified, leading to surgery interruption. Neurogenic mixed evoked potentials progressively reappeared after a 30-minute delay. Postoperation examination revealed a Brown-Sequard’s syndrome with incomplete right motor deficit.Conclusions.Neurogenic mixed evoked potentials evoked by anterior stimulation through thoracoscopy are of interest for spinal cord monitoring when posterior electrical stimulation is impossible, and they provide reliable information regarding spinal motor pathways.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID