摘要:

A biomechanical analysis of cervical distraction is presented, and a model comparing closed reduction of cervical spine dislocations to spring mechanics is developed. Behavior of a spring may be described as F = kδx where F = distraction force; δx = elongation of the spring; and k = spring constant. The records and roentgenograms of 24 cervical spine dislocations were reviewed retrospectively. Evaluation of cervical distraction vs traction weight indicates that Ftractlon= kneckδx; where F = traction weight and x = distraction at the injured level. The constant, kneck, is different for bilateral and unilateral dislocations (P<.001) and is a function of magnitude of injury and neck morphology. As determined in this study, traction weight needed for reduction of facet dislocations may be estimated using the formulae: Ftx= 107.1 Ibs/cm (x) unilateral, and Ftx= 76.4 Ibs/cm (x) bilateral.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

This study of 65 cases of fractured odontoid indicates that halo-thoracic bracing is an effective method for treatment of the Types II and III fractures. There were 28 Type II, and 19 Type III fractures treated with halo-thoracic braces. Of these 47 patients, only 4 went on to nonunion after an average of 8 weeks in the brace, a rate of bony union of 91.5%. Seven of the remaining 18 patients underwent primary fusion at C1–2, two were treated in Guilford braces, and six received no treatment. Surgery was performed if the fracture was unstable, if the patient could not be relied upon to leave the halo in place, or if the patient chose it as primary treatment. All seven of these patients went on to bony fusion. All of the six patients who refused treatment went on to nonunion of the fracture. Three patients were lost to follow-up.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Cervical manipulation may result in serious neurologic injury arising specifically from trauma to the vertebrobasilar system. The vertebral arteries are susceptible to trauma at three locations: in the transverse foraminae, at the atlantoaxial joint, and at the occipitoatlantal joint. Because of frequent inequality in the size of the two vertebral arteries, damage to the larger artery may lead to ischemia of the brain stem. Vertebral artery obstruction may be produced by extension with rotation, even within normal ranges of motion. Neurologic injury following manipulation requires accurate diagnosis and prompt manipulation requires accurate diagnosis and prompt anticoagulant therapy.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Eighty-two cases of primary neoplasms of the spine, diagnosed and treated at the University of Iowa, were reviewed in an attempt to identify features of diagnostic and prognostic importance, and to evaluate the effectiveness of surgical treatment with respect to survival. Thirty-one benign and 51 malignant tumors were identified. The mean follow-up in benign lesions was 9.7 years and 3.8 years in malignant lesions. Plain roentgenograms demonstrated the spinal lesion in 81 of 82 cases (99%). All spinal segments were involved, the cervical spine least frequently. Malignancy proved to be associated with an older age at diagnosis, a higher incidence of neurologic deficit, and a higher incidence of occurrence in the vertebral body. Five-year survival for patients with benign tumors was 86%, with no significant relationship between type of surgery and survival. Five-year survival in malignant lesions did correlate with the extent of initial surgery and with the tumor type. Five-year survival in patients undergoing curettage for malignancy was nil, in those undergoing incomplete resection, 18.7%, and in patients having complete excision, 75%. Plain anteroposterior and lateral roentgenograms should be obtained as a screening study in patients with persistent or atypical back pain or neurologic signs. CT scanning, myelography, and magnetic resonance imaging studies may be utilized to establish the physical margins of the lesion and to evaluate cord impingement. Surgical extirpation should be attempted whenever possible in malignant and benign aggressive lesions. In this series, the prolonged survival seen with complete excision justifies an aggressive surgical approach to the treatment of these tumors. Spine tumors should only be biopsied and treated by surgeons experienced in the approach and management of these most difficult problems.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

A coupling between the lateral flexion and axial rotation as a result of the geometric arrangement of the motion segments is well known in a normal spine. The kinematic behavior of idiopathic scoliotic spines has been analyzed by means of a biomechanical model study and a radiologic study. The anteroposterior and lateral flexion radiographs of 40 patients with progressive adolescent idiopathic scoliosis were studied. In five of these patients, anteroposterior radiographs were also made with the spine in a ventrally flexed position. The kinematic behavior of a nonpathologic spine was examined by means of a three-dimensional, nonlinear geometric mathematical model of the spine. The frontal plane inclination of the facet joints in conjunction with the vertebral orientation in the sagittal plane influence the kinematic behavior in the normal spine. In a scoliotic spine, there is an axially rotated position and, in most cases, a dorsal inclination (lordotic) of the motion segments. Nevertheless, the direction of the axial rotation during lateral flexion does not differ from the direction of the axial rotation during lateral flexion in a normal spine. The existing axial rotation in idiopathic scoliosis cannot be explained on the basis of spinal kinematics. In contrast to normal spines, in scoliotic spines exists a coupling between ventral flexion or extension and axial rotation. This may be essential in the management of idiopathic scoliosis.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Cardiorespiratory failure is the usual cause of death in severe kyphoscoliosis. The pathophysiology of this mechanism will be reviewed. Ventilatory muscle training (VMT), a relatively new respiratory technique, has been shown to improve the strength and endurance of the ventilatory muscles. It is known that stronger, endurance trained ventilatory muscles will guard against ventilatory muscle fatigue which may lead to respiratory failure. The actual technique is described with documentation of two representative cases. Case 1 showed a 63% increase in maximum inspiratory mouth pressure (PiMax) and an increased ability to walk and climb stairs with comfort. Case 2 used VMT as an adjunct to her weaning protocol from a portable ventilator. She progressed from full-time to nocturnal ventilator assistance in 1 month.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Somatosensory evoked potentials (SSEP) were recorded from the scalp for intraoperative monitoring of patients undergoing surgical correction of spine deformities or spine fractures. Alterations in the SSEP with distraction, spine manipulation, anesthesia, hypotension, and other intraoperative variables are described. When loss of the SSEP occurred and a waiting period was undertaken until it returned, all patients with an SSEP present upon closing, which was within ±2 SD of their anesthetized control values, had no neurologic complications. Alterations in SSEP consisting of increases in latency of 15% and decreases in amplitude of 50% were not associated with any postoperative neurologic deficits.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

A biomechanical study was performed comparing the stiffness and stability of Cotrel-Dubousset (CD) spinal instrumentation with that of segmentally wired Harrington distraction rods and segmentally wired Luque rods under conditions of single-level instability. The axial and torsional stiffness coefficients of each system were determined on a customized geometric spine simulator fashioned from stainless steel. The relative stability of each instrumentation system was then compared by mounting the fixation systems on bovine thoracic spines from 12-week-old calves, destabilized by anterior vertebrectomy to create simulated two column instability. Thirteen spines were tested. Each specimen was tested under axial and torsional loading conditions while monitoring with a personal computer-based data acquisition system was performed. The stability of first-and second-level CD instrumentation was tested on the bovine specimens. First-level CD instrumentation involved double-hook fixation one level above and below the level of instability. Second-level CD instrumentation involved fixation two levels above and below the level of instability without fixation at the intermediate level. In axial loading, double-level wired Harrington distraction rods, double-level wired Luque rods, and first-level CD rods were 26.5%, 18.4%, and 21.5%, respectively, as stable as second-level CD instrumentation. In torsion, double-level Harrington, double-level Luque, and second-level CD rods were 13%, 64%, and 34%, respectively, as stable as first level CD instrumentation. Locking hooks, double-hook configurations, and stabilizing transverse traction devices of the CD contributed to its greater stability. First-level CD instrumentation is recommended for rotational instability while second-level CD instrumentation is preferred for axial instability.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The “fixateur interne” is a new device for posterior spine surgery. It consists of long Schanz screws which are inserted from a posterior approach through the pedicles into the vertebral bodies, and of connecting threaded longitudinal rods, carrying mobile clamps which can be fixed in every position by nuts. The long leverarms of the Schanz screws facilitate manual reduction. They are removed at the end of operation. As the device is stable against flexion and rotation by itself, it does not act on the four-point bending principle. Thus, the fixation can be restricted to the immediately adjacent vertebrae of a lesion, leaving the rest of the spine mobile. In fracture treatment instrumentation is combined with a direct repair of the anterior loss of bone stock by a transpedicular bone grafting procedure from the same dorsal approach. This report presents and discusses 183 instrumentations in fresh fractures, posttraumatic deformities, degenerative diseases, tumors, and severe spondylolistheses. The main advantage is the short fixation area and the ease of after treatment.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The lumbar vertebral canal was measured in adult spines from two archaeological populations, and was compared with four physiological stress indicators, (cribra orbitalia, porotic hyperostosis, dental hypoplasia and Harris lines). The stature of 38 juvenile skeletons and their canal size were compared with those of the adults. By 4 years of age the midsagittal diameter and the area of the vertebral canal was fully mature and the mean interpedicular diameter 87% of adult size. There was a differential pattern of growth, with the proximal spine maturing first. The trefoil shape was not seen at L5 before puberty. Dental hypoplasia correlated with a small interpedicular diameter at L1, L2 and L3, and Harris lines with a small midsagittal diameter at L1, L3 and L5, a small area at L5 and a more trefoil canal at L4 and L5. There is evidence that adverse environmental factors are associated with the development of spinal stenosis.

ISSN:0362-2436    

出版商:OVID    

年代:1987

数据来源: OVID