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Biomedical subjects

R B Winter

Publications and source records attributed to R B Winter.

At least 73 records · Page 4Linked to original sources
PubMed1991

Luque-Galveston procedure for correction and stabilization of neuromuscular scoliosis and pelvic obliquity: a review of 68 patients.

Sixty-eight patients with neuromuscular spine deformity were treated by posterior spine fusion with Luque-Galveston instrumentation between 1982 and 1986. The minimum follow-up was 4 years. Diagnoses included cerebral palsy in 34 patients and other neuromuscular diseases in another 34 patients. The average age was 14 years. Twenty patients also had anterior spine fusion without instrumentation. Preoperatively the average scoliosis was 73 degrees and this was corrected to 33 degrees at final follow-up. The subgroup having anterior discectomy and fusion had a more severe scoliosis and pelvic obliquity, but the percent of correction was similar to that of the group with posterior reconstruction only. Twenty-four patients who had an associated significant sagittal plane deformity were corrected to a physiologic curvature. A postoperative thoracolumbosacral orthosis was used in 27 patients, and a molded seating orthosis was used in 18. Although the rate of complications was high (62%), most of them were minor. Instrumentation problems occurred in 14 patients (21%), only 4 of them having broken rods. There were no broken wires. Pseudarthrosis occurred in seven patients (10%). Three patients had minor neurologic deficits, all transient. The "windshield-wiper" sign was defined as any radiolucency of 2 mm or greater. Twenty-six patients had this sign at follow-up, and this group had a higher percentage of complications, but the existence of this sign did not necessarily indicate a problem.

Adolescent↗
PubMed1991

Biomechanical analysis of transpedicular rod systems. A preliminary report.

Two transpedicular spinal instrumentation systems were developed for fixation of the lumbosacral junction: a transpedicular fixator and the transpedicular screw/rod system. Mechanical testing showed that the new systems have a rigidity that is intermediate between conventional wired implants (Galveston and Luque ring) and plate systems (Steffee plate). Neither pedicular implant approached the rigidity of the Steffee plate with S2 fixation, but in compression and anterior bending both were more rigid than the Steffee plate without S2 fixation. Despite the apparent mechanical advantages of the transpedicular fixator, it is currently too bulky for clinical use. The transpedicular screw/rod system is more appealing because the size leaves adequate area for bone grafting, and device placement is technically simple. Furthermore, it may be contoured to any plane, while retaining stability provided by the clamps and screws.

Biomechanical Phenomena↗
PubMed1991

Cloning and characterization of a Pseudomonas mendocina KR1 gene cluster encoding toluene-4-monooxygenase.

Pseudomonas mendocina KR1 metabolizes toluene as a carbon source by a previously unknown pathway. The initial step of the pathway is hydroxylation of toluene to form p-cresol by a multicomponent toluene-4-monooxygenase (T4MO) system. The T4MO enzyme system has broad substrate specificity and provides a new opportunity for biodegradation of toxic compounds and bioconversions. Its known activities include conversion of a variety of phenyl compounds into the phenolic derivatives and the complete degradation of trichloroethylene. We have cloned and characterized a gene cluster from KR1 that determines the offO activity. To clone the T4MO genes, KR1 DNA libraries were constructed in Escherichia coli HB101 by using a broad-host-range vector and transferred to a KR1 mutant able to grow on p-cresol but not on toluene. An insert consisting of two SacI fragments of identical size (10.2 kb) was shown to complement the mutant for growth on toluene. One of the SacI fragments, when cloned into the E. coli vector pUC19, was found to direct the synthesis of indigo dye. The indigo-forming property was correlated with the presence of T4MO activity. The T4MO genes were mapped to a 3.6-kb region, and the direction of transcription was determined. DNA sequencing and N-terminal amino acid determination identified a five-gene cluster, tmoABCDE, within this region. Expression of this cluster carrying a single mutation in each gene demonstrated that each of the five genes is essential for T4MO activity. Other evidence presented indicated that none of the tmo genes was involved in the regulation of the tmo gene cluster, in the control of substrate transport for the T4MO system, or in major processing of the products of the tmo genes. It was tentatively concluded that the tmoABCDE genes encode structural polypeptides of the T4MO enzyme system. One of the tmo genes was tentatively identified as a ferredoxin gene.

Amino Acid Sequence↗
PubMed1991

Salvage and reconstructive surgery for spinal deformity using Cotrel-Dubousset instrumentation.

Sixty consecutive patients who underwent Cotrel-Dubousset instrumentation as part of their reconstructive surgery (failure of previous surgery) were reviewed. The average follow-up was 3 years (range, 2-4.5 years). There were no deaths or major neurologic problems. Pseudarthrosis occurred in six patients, all of whom had long fusion to the sacrum; all six were successfully repaired. Cotrel-Dubousset instrumentation provides a far superior method of correction of deformity and internal fixation than that available previously.

Adolescent↗
PubMed1990

Long scoliosis fusion to the sacrum in adults with nonparalytic scoliosis. An improved method.

The first 17 adults with nonparalytic scoliosis having long fusion to the sacrum treated with the Luque-Galveston technique were reviewed. There were 3 men and 14 women. Their average age at the time of surgery was 47 years and the mean follow-up period was 42 months. There were no neurologic complications and no patient developed significant loss of lumbar lordosis. Fusion occurred in 88% of patients. Two patients developed pseudarthrosis, neither of whom had anterior fusion at the level of pseudarthrosis. The best results occurred in patients who had two-stage procedures, with initial anterior lumbar fusion to the sacrum without instrumentation followed by posterior segmental instrumentation with the Galveston technique of fixation to the pelvis.

Female↗
PubMed1990

Factors affecting fusion rate in adult spondylolisthesis.

The authors examined factors affecting fusion rate in the surgical treatment of 89 consecutive adult patients with spondylolisthesis. Two factors significantly improved fusion rate: combined anterior and posterior fusion and rigid postoperative immobilization in the cast. In 65 patients with isthmic spondylolisthesis, the fusion rate was raised from 70% when posterior fusion alone was used to 88% when combined anterior and posterior fusion was used. In 20 patients with degenerative spondylolisthesis, frequent use of combined anterior and posterior fusion contributed to a high overall fusion rate of 95%. Among patients with isthmic spondylolisthesis, postoperative cast immobilization resulted in a higher fusion rate of 90% compared with a fusion rate of 63% obtained after brace immobilization.

Adult↗
PubMed1990

Scoliosis in trisomy 18.

Patients with trisomy 18 typically present with multiple congenital anomalies and most die within the first year. However, long-term survivors are not uncommon. Seventeen patients with trisomy 18 were evaluated to study the development of scoliosis associated with this disorder. There were 13 females and 4 males with ages ranging from birth to 22 years. Twelve patients died by age 2. None developed scoliosis or had vertebral anomalies. The five patients who survived beyond age 2 developed scoliosis. Curve progression was demonstrated in the patients who returned for follow-up. Bracing was not well tolerated in two patients with curves of 48 degrees and 58 degrees. Both had poor motor control and sitting ability. One patient with a 30 degree curve was successfully managed by bracing. Another patient with a severe scoliosis was successfully fused with anterior and posterior instrumentation. Patients with trisomy 18 should be carefully evaluated for scoliosis. Scoliosis in the older child, surviving beyond age 2, may be progressive and difficult to manage.

Abnormalities, Multiple↗
PubMed1989

The idiopathic double thoracic curve pattern. Its recognition and surgical management.

Recognition of the idiopathic double primary thoracic curve pattern has become increasingly important as more effective methods of internal correction of curves have been developed. Overcorrection of the lower thoracic curve beyond the spontaneous correctability of the upper thoracic curve may lead to an undesirable asymmetric neck and shoulder contour.

Adolescent↗
PubMed1989

The role of hip location and dislocation in the functional status of the myelodysplastic patient. A review of 100 patients.

One hundred patients 10 years of age or older with myelodysplasia were evaluated to compare located versus dislocated hips with regard to neurologic level, ambulation, hip pain, skin condition, and spinal deformity. Operated and nonoperated individuals were compared. Analysis was carried out to determine what the overall long-time function was in located, dislocated, and "relocated" individuals. Of the 100 patients, 72 presented at follow up with bilateral located hips, 18 with unilateral hip dislocations, and 10 with bilateral dislocations. Twenty patients functioned at T12 levels or above, 30 patients had preservation of anterior thigh musculature, and 25 patients had posterior leg or hip abductor power. Thirteen patients (15 hips) were found to have some degree of pain, 1 patient with bilateral dislocation, 5 with unilateral dislocation, and 7 with bilaterally located hips. Ambulatory function was not affected in any neurologic group by location versus dislocation of the hips. Skin ulceration problems were not increased in patients with hip dislocation. Major spinal deformity in most groups correlated highly with neurologic levels, but not with location versus dislocation of the hips. In one group, an increase in lumbar lordosis was present in unilateral hip dislocations. This study suggests that adolescents and young adults with myelodysplasia have different functional levels related to the neurologic level which are not related to whether the hips are located or dislocated.

Adolescent↗
PubMed1989

Management of neuromuscular spinal deformities with Luque segmental instrumentation.

Forty-six patients who had a neuromuscular spinal deformity were treated with arthrodesis and Luque segmental spinal instrumentation and were followed for an average of three years. Twenty-two patients had cerebral palsy and twenty-four had another neuromuscular disease. In thirty-nine patients, the arthrodesis was extended to the sacrum. Eleven patients who had severe scoliosis as well as pelvic obliquity and decompensation of the torso had a combined anterior and posterior arthrodesis; the other thirty-five patients had a one-stage posterior procedure. Preoperatively, the average scoliosis was 74 degrees; this was corrected to 39 degrees at follow-up. Final corrections were similar for scoliosis and were better for pelvic obliquity and decompensation of the torso in patients who had combined anterior and posterior arthrodesis. The results for scoliosis and pelvic obliquity in patients who had a spastic deformity were similar to the results in patients who had a flaccid deformity. Correction of decompensation of the torso was better in patients who had a spastic deformity. Postoperatively, a brace was used in half of the patients in each group; this did not appear to affect the amount of correction in either group, although the result may have been influenced by the selection process. The rate of complications was 48 per cent. Pseudarthrosis occurred in three patients (6.5 per cent). There were no major neurological deficits related to the correction or to the use of sublaminar wires. Three patients died, one in the immediate postoperative period and the other two at eighteen months and four years after the original procedure, due to causes unrelated to the operation.

Adolescent↗
PubMed1989

Surgical treatment of adolescent idiopathic scoliosis. A comparative analysis.

Three hundred and fifty-two patients had a one-stage posterior spinal arthrodesis between 1960 and 1984 using one of four types of instrumentation: a Harrington distraction rod, Harrington distraction and compression rods, Harrington distraction and compression rods with a device for transverse traction, and a Harrington distraction rod with sublaminar wires. All of the patients were female (age-range, eleven to nineteen years), and all had idiopathic scoliosis with a single right or double thoracic curve. The minimum length of follow-up was two years. No significant difference was found among the four groups relative to the amount of correction that was obtained at operation or maintained two years after operation. An average of 13.5 per cent of correction was lost during follow-up in the patients who were treated with postoperative immobilization, and an average of 27 per cent was lost in the patients who were treated with sublaminar wires without immobilization. The use of a straight Harrington rod reduced normal thoracic kyphosis, the addition of a compression rod corrected hyperkyphosis, and the use of a rod with sublaminar wires corrected thoracic hypokyphosis or thoracic lordosis.

Adolescent↗
PubMed1989

Adult idiopathic scoliosis treated with Luque or Harrington rods and sublaminar wiring.

We reviewed the results of spinal arthrodesis that was performed, with sublaminar wires that were attached to either double L-shaped Luque rods or to a Harrington rod, in forty-two adults who had idiopathic scoliosis. The minimum length of follow-up was two years; the maximum, five years; and the average, three years. The average scoliosis measured 67 degrees preoperatively, was corrected to 37 degrees at operation, and was 44 degrees at the time of follow-up. The final correction averaged 34 per cent. A single Harrington rod and multiple sublaminar wires were used in thirty-one patients. Eighteen of the thirty-one patients had a posterior arthrodesis only and thirteen, a preliminary anterior arthrodesis followed by a posterior arthrodesis. Eleven patients had instrumentation with double L-shaped Luque rods; six of them had posterior arthrodesis only and five, a preliminary anterior arthrodesis followed by a posterior arthrodesis. One patient had neurological deficit that was related to the operation. Three patients had a pseudarthrosis, which was in the lumbar area in all of them. All three patients had had only a posterior operation. No statistically significant difference in the amount of final correction was demonstrated between the subgroups.

Adult↗
PubMed1988

Pain patterns in adult scoliosis.

Adult patients with scoliosis often have back pain, but that pain may or may not be due to the curvature. A careful history, physical examination, routine radiographic examination, and, on some occasions, specialized radiographs, CT, myelography, discography, and facet joint injection will help the physician or surgeon separate out those pain syndromes owing to the curvature versus those not owing to the curvature. Only after these critical evaluations have been done can a decent decision be made as to the area of the spine to be treated, either surgically or nonsurgically.

Adult↗
PubMed1988

Neurofibromatosis hyperkyphosis: a review of 33 patients with kyphosis of 80 degrees or greater.

Thirty-three patients with hyperkyphosis secondary to neurofibromatosis were reviewed as to the natural history of the deformity, complications of the untreated deformity, and results of treatment. The kyphoses ranged from 80 to 180 degrees, averaging 132 degrees. The natural history was not good, six patients presenting with paraparesis and six with respiratory distress. Twenty-seven patients had operative treatment. Laminectomy was useless for the treatment of paraparesis due to angulated spine deformity. Combined anterior and posterior spine fusion using abundant amounts of autogenous bone for both, coupled with prolonged rigid immobilization, gave the best results. Halo traction and halo casts were invaluable for the more severe deformities. Instrumentation was often impossible due to the severe deformity. All patients operated on by the authors eventually achieved solid union.

Adolescent↗
PubMed1988

Adolescent idiopathic scoliosis. Nonoperative treatment.

Various nonoperative treatments are discussed. In the authors' clinics, the Milwaukee brace is used occasionally for the patient with a thoracic scoliosis in whom the electrical stimulator could not be used, or when the parents wish to try another form of nonoperative therapy when the stimulator has failed. The Milwaukee brace is still the treatment of choice for juvenile idiopathic scoliosis.

Adolescent↗