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Biomedical subjects

R N Hensinger

Publications and source records attributed to R N Hensinger.

At least 37 records · Page 2Linked to original sources
PubMed1991

Fusion of the upper cervical spine in children and adolescents. An analysis of 17 patients.

A retrospective review of 17 immature patients who underwent posterior spinal fusion of C1-C2 or C1-C3 was performed to establish the efficacy of the procedure, to determine the incidence of complications, and to identify those at high risk for complications. All had radiographic C1-C2 instability or dislocation. Etiologies included os odontoideum, fixed rotatory subluxation, atlantoaxial subluxation, type II dens fracture nonunion, and nonunion of a Hangman's fracture. Before surgery, 10 patients were neurologically intact, and seven had neurologic findings. Associated diagnosis included Down's syndrome in three and Ehler-Danhlos in one. Follow-up averaged 25 months. One neurologically intact patient had a C2 radiculopathy that resolved by 1 year. Three patients with Down's syndrome had complications: one with a preoperative Brown-Sequard syndrome had transient worsening in the immediate postoperative period, one with a preoperative myelopathy developed a late recurrence of a severe myelopathy that required odontectomy, and another sustained an intraoperative spinal cord contusion followed by postoperative quadriplegia and death due to respiratory failure. Of seven reporting neurologic symptoms before surgery, two had residual deficit in the late postoperative period. These two represented preventable technical errors. There were two nonunions, one of which required occiput to C2 fusion. In general, posterior spinal fusion of the upper cervical spine was found to be a reliable, safe, and predictable procedure, but extra caution should be employed when considering arthrodesis in patients with ongoing spinal cord compression, fixed dislocations, and inherited ligamentous laxity.

Adolescent↗
PubMed1991

Complications of fusion to the upper cervical spine.

Forty-seven operations for posterior fusion of the upper cervical spine were reviewed for complications. Alarmingly, only 11 patients had an entirely uncomplicated course. Most complications were minor, but there were four nonunions, one requiring reoperation. Although seven patients had increased neurologic deficits after surgery, only one was permanent. There was one death due to technical error. Patients with significant instability, myelopathy, prior failed fusions, or unreducible dislocations are at high risk for perioperative neurologic complications.

Adult↗
PubMed1991

Familial cervical dysplasia.

Nine of twelve family members from three generations were affected by an inherited form of cervical vertebral dysplasia. All of the affected people had an abnormality of the first cervical vertebra. Some also had defects of the axis and caudad to it. The mode of transmission of the disorder is autosomal dominant, with apparently complete penetrance and variable expressivity. Two patients had symptoms. One had a passively correctable tilt of the head, with an associated audible clunk and hypoplasia of the left superior facet of the second cervical vertebra. This patient had no local symptoms, neurological involvement, or muscle spasm. In the other patient, suboccipital pain developed. Radiographs revealed an anterior atlanto-occipital dislocation. The symptoms resolved after reduction and arthrodesis. Because of the apparently complete penetrance of this disorder, physicians caring for patients who have this type of congenital malformation of the cervical spine should consider examination of closely related members of the family. Clinical findings such as tilting of the head, torticollis, or limitation of cervical motion suggest that additional evaluation should be done. The examination should include lateral radiographs of the cervical spine in flexion and extension. Three-dimensional computed-tomography reformatting was helpful in demonstrating the complex cervical anatomy in our patients. Patients who have recognized abnormalities should be followed and should be re-examined whenever local or neurological symptoms develop. A magnetic resonance image of the spine in flexion and extension was valuable for identification of the potentially disastrous situation of impending damage to the cord in patients who had instability and evolving symptoms.

Adult↗
PubMed1991

Congenital anomalies of the cervical spine.

Congenital anomalies of the cervical spine are uncommon. The majority of afflicted individuals are asymptomatic or have only mild restriction of neck motion. If symptoms develop, they are usually due to cervical instability or degenerative osteoarthrosis. Recent information indicates that patients with upper cervical anomalies such as atlantooccipital fusion, anomalies of the odontoid, or the transverse atlantal ligament have a great propensity to develop early instability and neurologic problems secondary to minor traumatic events. If symptoms occurs in the lower cervical spine, it is usually in adult life and due to degenerative arthritis in the hypermobile articulations adjacent to the area of synostosis. The relatively good prognosis of cervical lesions is overshadowed by the "hidden" or unrecognized associated anomalies. There is a high incidence of significant scoliosis, Sprengel's deformity, renal anomalies, deafness, and neurologic malformations. Early recognition and treatment of these problems may be of substantial benefit, sparing the patient further deformity or serious illness.

Adolescent↗
PubMed1990

Cobb angle versus spinous process angle in adolescent idiopathic scoliosis. The relationship of the anterior and posterior deformities.

The standard clinical measurement for adolescent idiopathic scoliosis is the Cobb angle, measured from the end-plates of the end vertebral bodies in a standing radiograph. This measurement of anterior column structures describes the anterior spinal deformity. The posterior spinal deformity can be described by the "spinous process angle," measured from a curve joining the tips of the spinous processes. A computer model, and a radiographic study of Cobb angle, spinous process angle and vertebral rotation show that adolescent idiopathic scoliosis results in larger angulations of the anterior elements than posterior elements. This helps to explain some of the inherent limitations of posterior instrumentation, including Cotrel-Dubousset instrumentation, and of noninvasive posterior surface measurement systems.

Adolescent↗
PubMed1989

The management of rotatory atlanto-axial subluxation in children.

Twenty-three children who were treated for rotatory atlanto-axial subluxation between 1975 and 1986 were retrospectively studied. The success of closed reduction with traction and the length of hospitalization were related to the duration of symptoms before admission. In sixteen of the children, who were seen less than a month after the onset of symptoms, the subluxation reduced either spontaneously or after a short period of traction. Of the seven remaining children, who were seen more than one month after the onset of symptoms, three eventually needed a posterior atlanto-axial arthrodesis. Dynamic computed-tomography scans, with the head rotated maximally to each side, were made for five children, and proved to be an excellent method of documenting the presence of rotatory atlanto-axial subluxation.

Adolescent↗
PubMed1989

Emergency transport and positioning of young children who have an injury of the cervical spine. The standard backboard may be hazardous.

In ten children who were less than seven years old, an unstable injury of the cervical spine was found to have anterior angulation or translation, or both, on initial lateral radiographs that were made with the child supine on a standard flat backboard. In all ten patients, extension was the proper position for reduction of the injury of the cervical spine. Young children have a large head in comparison with the rest of the body. When a young child is positioned on a standard backboard, the neck may be forced into relative kyphosis. Supine and upright lateral radiographs that were made of seventy-two children who did not have a fracture also demonstrated more relative cervical kyphosis in younger children when they were in the supine position. Calculations from anthropometric data documented disproportionate rates of growth of the head and the chest. The circumference of the head grows logarithmically, but the circumference of the chest grows linearly. This disproportionate growth causes young children to have a relatively large head. When they lie supine, the neck is flexed. To prevent undesirable cervical flexion in young children during emergency transport and radiography, a standard backboard can be modified to provide safer alignment of the cervical spine. This can be accomplished by the use of a recess for the occiput to lower the head or of a double mattress pad to raise the chest.

Age Factors↗
PubMed1988

Wisconsin and other instrumentation for posterior spinal fusion.

In idiopathic scoliosis, the Wisconsin system is as safe as a Harrington rod and nearly as strong as a Luque construct. The installation is relatively easy. Sagittal curves can be preserved while correcting the scoliosis by contouring the rods and fixing them to the spine in a segmental fashion. The Wisconsin system is currently the instrumentation of choice at the authors' clinic for routine idiopathic scoliosis. The quest for the ideal spinal instrumentation system will probably never end. Further improvements on the current systems will inevitably appear, and new concepts will be developed. Spine surgeons will continue to be faced with the need to compare the advantages and disadvantages of different systems.

Equipment Design↗
PubMed1988

Control of blood loss during scoliosis surgery.

By combining surgical and anesthetic techniques that minimize blood loss with the use of autotransfusion, it should now be possible to complete a routine posterior spinal fusion without using allogeneic blood transfusions. Surgical efforts should include careful preoperative planning, positioning with the abdomen hanging free, use of topical hemostatic agents, and decortication late in the procedure. Preoperatively donated autogeneic blood or reclaimed red cells from suction can take the place of allogeneic transfusions. Blood loss during scoliosis surgery correlates closely with left ventricular stroke work index (LVSWI), a measure of blood flow calculated from systemic vascular resistance, cardiac output, and heart rate. All of these parameters are under the anesthesiologist's control, making him the primary determinant of blood loss in scoliosis surgery. Induced hypotensive anesthesia may be ineffective in controlling blood loss if the cardiac output or heart rate is high. Halothane, a commonly used hypotensive agent, is not very useful for scoliosis surgery because spinal cord monitoring and wake-up testing are not possible. Rebound hypertension has been noted with the use of sodium nitroprusside. Trimethaphan works well clinically but experimentally it reduces spinal cord blood flow, which may increase the risk of spinal cord injury.

Anesthesia↗
PubMed1987

Arthrography in evaluation of birth injuries of the shoulder.

Birth injuries of the shoulder and proximal humerus of infants can be difficult to evaluate on plain radiographs because of lack of ossification in the proximal humeral epiphysis. We here describe arthrography of the infant shoulder and advocate it as a useful diagnostic procedure in the evaluation of humeral fractures and brachial palsies. Two infants with birth injuries of the shoulder are described. The value of dynamic fluoroscopic evaluation of the injured joint in conjunction with arthrography is illustrated in evaluation of a brachial plexus palsy.

Arthrography↗
PubMed1987

Congenital dislocation of the hip. Treatment in infancy to walking age.

Early management of congenital dislocation of the hip has been necessary and has resulted in a high percentage of normal-appearing and functioning hips. The risk of complications and problems has been lessened. Further, the techniques employed are simpler and less demanding or difficult for patients, family, or physicians.

Female↗