PubMed Health⌕ Search

Biomedical subjects

G S Bassett

Publications and source records attributed to G S Bassett.

At least 19 recordsLinked to original sources
PubMed2001

Prospective comparison of flexibility radiographs in adolescent idiopathic scoliosis.

STUDY DESIGN: A prospective evaluation of radiographs in patients undergoing anterior spinal fusion or posterior spinal fusion for adolescent idiopathic scoliosis. OBJECTIVE: To determine the most effective preoperative radiographic method for evaluating coronal plane flexibility by comparing preoperative and postoperative correction. SUMMARY OF BACKGROUND DATA: Curve flexibility is traditionally evaluated with side-bending radiographs. Recently, the fulcrum-bending radiograph was shown to provide better correction of thoracic curves undergoing posterior spinal fusion but was not evaluated in thoracolumbar/lumbar curves or in patients undergoing anterior spinal fusion. METHODS: Preoperative coronal radiographs of 46 consecutive patients undergoing spinal fusion for adolescent idiopathic scoliosis obtained while standing, lying supine, side-bending (maximally bending while supine), push-prone (padded bolsters applied to chest wall while prone), and fulcrum-bending (curve apex suspended over a radiolucent fulcrum while lateral) were compared with standing postoperative radiographs. Cobb angles were determined and evaluated for statistical significance. RESULTS: The fulcrum-bending radiograph demonstrated statistically better correction than other preoperative methods for main thoracic curves (P < 0.01) but fell short of demonstrating the correction obtained surgically. There was no statistical difference between side-bending, fulcrum-bending, or postoperative correction for thoracolumbar/lumbar curves (all P values > 0.07). The left side-bending was the most effective method for reducing upper thoracic curves (P < 0.001). There was no difference in the results obtained for curves corrected by anterior spinal fusion or anterior spinal fusion. CONCLUSION: To achieve maximal preoperative correction, thoracic fulcrum-bending radiographs should be obtained for evaluating main thoracic curves, whereas side-bending radiographs should continue to be used for evaluating both upper thoracic and thoracolumbar/lumbar curves.

Adolescent↗
PubMed2001

Retrosternal displacement after physeal fracture of the medial clavicle in children treatment by open reduction and internal fixation.

Retrosternal displacement of the medial aspect of the clavicle after physeal fracture is rare. We treated six patients with this injury between 1995 and 1998, all as an emergency in order to avoid complications associated with compression of adjacent mediastinal structures. Attempted closed reduction was undertaken, but all required open reduction and internal fixation using a wire suture. There were no associated complications. Five were reviewed clinically and radiologically at a minimum of one year after operation. All had regained full use of the affected arm without pain and had resumed their preinjury level of activity including sports. Follow-up radiographs showed union in the anatomical position in all patients. We recommend attempted closed reduction in the operating room, followed, if necessary, by open reduction. Internal fixation after open reduction gives stable fixation with minimal morbidity.

Adolescent↗
PubMed2000

A prospective comparison of neurogenic mixed evoked potential stimulation methods: utility of epidural elicitation during posterior spinal surgery.

STUDY DESIGN: A prospective study of 50 patients who underwent posterior thoracic or thoracolumbar instrumented spinal surgery from June 1998 through June 1999. OBJECTIVES: To highlight the advantages and disadvantages of neurogenic mixed evoked potential (NMEP) data obtained with three methods of stimulation: epidural, spinous process, and percutaneous. SUMMARY OF BACKGROUND DATA: Reports in the literature have established the efficacy of epidural, spinous process, and percutaneous stimulation of the NMEP response. The three methods have not been compared for reliability, sensitivity, and specificity. METHODS: The study group consisted of 50 patients who underwent posterior thoracic or thoracolumbar instrumented spinal surgery from June 1998 through June 1999. Somatosensory-evoked potentials were used to monitor upper and lower extremities. An attempt to obtain NMEPs was made in all patients by using percutaneous (PERC-NMEP), spinous process (SP-NMEP), and epidural (EPI-NMEP) stimulation. These data were evaluated for reliability, sensitivity, and specificity. The number of minutes monitored in the postcorrection period were calculated for each method, and stimulus intensities were noted. RESULTS: In the current study, PERC-NMEPs were obtained in 88% of the patients and were maintained in 91% of those cases, SP-NMEPs were obtained in 96% and maintained in 77%, and EPI-NMEPs were obtained in 100% and maintained in 88%. Data collection continued in the postcorrection period for 46 minutes for PERC-NMEPs, 19 minutes for SP-NMEPs, and 23 minutes for EPI-NMEPs. The study group had no true-positive or false-negative findings. CONCLUSIONS: Results showed that EPI-NMEPs provide reliable data in a greater number of patients than either SP-NMEPs or PERC-NMEPs. However, PERC-NMEP data are readily maintained during and after the critical time window after corrective spinal maneuvers. The NMEPs elicited with both percutaneous and epidural stimulation have a useful role in an intraoperative spinal cord-monitoring protocol.

Adolescent↗
PubMed2000

Parents' and patients' preferences and concerns in idiopathic adolescent scoliosis: a cross-sectional preoperative analysis.

STUDY DESIGN: A multicenter cross-sectional study of parents' and patient's concerns and preferences regarding surgery for idiopathic scoliosis. OBJECTIVES: The purpose of this study was to analyze independently both the parents' and patients' assessments of upcoming surgery for idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: No group has recently reported querying patients and their parents regarding expectations, preferences, reasons, and concerns about and for surgical treatment of adolescent idiopathic scoliosis. METHODS: Ninety-one sets of parents and patients were separately asked to complete questionnaires regarding the patients' upcoming idiopathic scoliosis surgery. Patients' ages ranged from 9 to 18 years, and data were collected from four centers and seven surgeons (all active members of the Scoliosis Research Society) from April through December 1998. Thirty-nine questions covered concerns (n = 6), reasons for surgery (n = 14), expectations (n = 9), assessment of life as is (n = 5), and scar preference (n = 5). RESULTS: The greatest concern about the surgery expressed by both parents and patients was neurologic deficit. The least concern for both was location and appearance of the scar. The highest expectation and main reason for having the surgery was to reduce future pain and disability as an adult. Families would be either somewhat or very dissatisfied to spend the rest of life "as is." CONCLUSION: Although parents and patients had similar ratings and concerns, the parents' concerns were higher, and expectations were greater than the patients'.

Adolescent↗
PubMed1999

Efficacy of intraoperative monitoring for pediatric patients with spinal cord pathology undergoing spinal deformity surgery.

STUDY DESIGN: A retrospective study of 38 pediatric patients with spinal cord pathology who underwent corrective spinal deformity surgery from January 1989 through June 1998. OBJECTIVES: To report reliability and specificity in obtaining intraoperative data in this population. These data were compared with monitoring results obtained in a group of pediatric patients with idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Reports in the literature suggest intraoperative monitoring for patients with spinal cord pathology may be of limited value. No optimal monitoring protocol has been suggested for this population. METHODS: The study group consisted of 38 pediatric patients with a diagnosis of spinal cord pathology who underwent corrective spinal deformity surgery from January 1989 through June 1998. All patients had lower extremity function. Somatosensory and neurogenic motor evoked potentials were used to monitor neurologic status during surgery. These data were compared with data obtained in 429 pediatric patients with idiopathic scoliosis. Study patients were divided into Group I, those who had had spinal cord surgery (n = 20), and Group II, those who had not (n = 18). RESULTS: Somatosensory evoked potentials were obtained in 93.2% and remained consistent with baselines in 87.2% of the study group patients. Neurogenic motor evoked potentials were obtained in 50.8% of the study subjects and remained consistent in 76.6% of those cases. The false-positive rate was 27.1% in the study group, compared with 1.4% in the group with idiopathic scoliosis. The study group had no true-positive or false-negative findings. Group I data differed from Group II data. CONCLUSIONS: Intraoperative monitoring should be used in patients with spinal cord pathology who undergo surgery for spinal deformity. Monitoring should not miss a neurologic deficit but demonstrates greater variability, resulting in more frequent use of an intraoperative wake-up test.

Adolescent↗
PubMed1998

Hypoglossal nerve injury caused by halo-suspension traction. A case report.

STUDY DESIGN: A case report of injury to the hypoglossal nerve (CN XII) resulting from the use of halogravity traction in a child with severe cervicothoracic kyphosis after an anterior and posterior spinal release. OBJECTIVE: To describe one of the potential dangers of halo-suspension (gravity) traction, which has not been reported previously in the orthopedic literature. SUMMARY OF BACKGROUND DATA: Cranial nerve injuries resulting from halo-skeletal traction are a recognized complication of such treatment, especially in patients with myelomeningocele. Halo-suspension traction using the patient's body weight as counter-traction has been recommended to provide a less rigid force and to reduce complications. METHODS: The authors report on the mechanism of injury and clinical course in a 12-year-old boy with myelomeningocele and a bilateral CN XII injury caused by halo-suspension traction from onset to resolution. RESULTS: This patient had dysphagia and difficulty swallowing 5 days after surgery. His wheelchair traction at this point was approximately 40% of his body weight. The traction was reduced, and a corticosteroid was administered. The patient's symptoms began to abate 5 days later. At 6 weeks after injury, his cranial nerve function was normal. CONCLUSIONS: Although halo-suspension traction or halo-wheelchair traction may be less rigid, injury to the hypoglossal nerve can be produced with traction exceeding 40% of body weight. In the patient in the current report, resolution of this injury was complete within 5 weeks, an outcome that is consistent with those of other reported cases of CN XII injury.

Adrenal Cortex Hormones↗
PubMed1998

The prognostic importance of the ossific nucleus in the treatment of congenital dysplasia of the hip.

Ischemic necrosis of the femoral head occurring after the treatment of congenital dysplasia of the hip can negatively affect the long-term prognosis of the involved hip. Some investigators have suggested that the presence of the ossific nucleus of the femoral head at the time of closed or open reduction is associated with a lower rate of ischemic necrosis. This finding, if verified, could lead to a delay in the treatment of a dislocated hip until ossification of the femoral head has begun, which may be well after the age when the patient has started to walk. We conducted a computerized search of the medical records at our two tertiary-care children's hospitals to identify all patients with congenital dysplasia of the hip who had had a closed or open reduction between January 1, 1979, and December 31, 1993. One hundred and twenty-four patients (153 hips) who satisfied the criteria for inclusion were identified. The ossific nucleus was present in ninety hips and absent in sixty-three. Closed reduction was used in 112 hips and open reduction, in forty-one. Ischemic necrosis was identified in five hips (3 percent): four (6 percent) of the sixty-three hips that did not have an ossific nucleus and one (1 percent) of the ninety hips that had an ossific nucleus at the time of the reduction. With the numbers available for study, we could not detect a difference between these two groups. The age at reduction (p > 0.99), the method of reduction (p = 0.611), previous treatment with a Pavlik harness (p = 0.592), the use of preliminary traction (p = 0.602), concomitant procedures (p > 0.99), and a failure of the primary closed reduction (p = 0.579) were not associated with the development of ischemic necrosis after reduction. In our analysis of patients who were managed over a fifteen-year period, the data did not support the hypothesis that the presence of an ossific nucleus at the time of reduction of a congenitally dislocated hip is associated with a lower prevalence of ischemic necrosis of the femoral head. Sound operative principles dictate that operative reduction of a congenitally displaced hip should be performed when the child can be safely placed under anesthesia and without regard to the presence or absence of the ossific nucleus.

Case-Control Studies↗
PubMed1997

Psoas over the brim lengthenings. Anatomic investigation and surgical technique.

Lengthening of the psoas tendon commonly is performed for various conditions of the hip including developmental dysplasia and neuromuscular contractures and instability. Anecdotal reports of injury to surrounding neurovascular structures suggest an investigation of the local anatomy is warranted. Using magnetic resonance images from 54 children younger than 10 years, the authors examined the anatomic relationship between major neurovascular structures (femoral artery and vein, external iliac artery and vein, femoral nerve) and the psoas tendon. The mean distance between the neurovascular structures and the psoas tendon in the over the brim position is 1 cm, although it may be as close as 4 mm in a child. The mean distance is 3.1 cm at the tendon's insertion at the lesser trochanter. Surgeons performing psoas over the brim lengthenings should be aware that major neurovascular structures may be only 4 mm from the psoas tendon. The recommended surgical technique is presented.

Cadaver↗
PubMed1997

Laser Doppler flowmetry during open reduction for developmental dysplasia of the hip.

Laser Doppler flowmetry was used intraoperatively to monitor femoral head perfusion during open reduction of 13 congenital hip dislocations in 11 patients. Laser Doppler determinations ranged from 12 to 400 mV before reduction and 30 to 300 mV after reduction. Three patients had magnitude changes in excess of 50%. One had increased perfusion, and two had decreased blood flow. Avascular necrosis of the hip occurred in one patient that was not predicted by laser Doppler flowmetry. Femoral head perfusion measured 175 mV for the dislocated hip and 180 mV after reduction of the femoral head and completion of the pelvic osteotomy. The authors conclude that laser Doppler flowmetry is not a reliable method for monitoring femoral head perfusion during open reduction of the hip for developmental hip dysplasia.

Child, Preschool↗
PubMed1997

The use of the Ilizarov technique in the correction of lower extremity deformities in children.

The first time the Ilizarov technique was used at Children's Hospital of Los Angeles, 25 limb segments were treated in 15 patients. Thirteen segments (52%) required angular correction, 6 (24%) required lengthening, and 6 (24%) required both angular correction and lengthening. Average angular correction was 21 degrees (8 degrees to 41 degrees); average length gained was 44 mm (25 to 85 mm). All patients except two achieved preoperative goals. A total of 17 minor (.68/limb) and four major (.16/limb) complications occurred in the 25 limb segments in the study. The total complication rate was .84 complications per limb segment. The most common complication was pin tract infection (11 patients). This comprised 52% of complications and occurred in 44% of limb segments.

Adolescent↗
PubMed1996

Adolescent idiopathic scoliosis: an update.

Adolescent idiopathic scoliosis is defined as a lateral spinal curvature of greater than 10 degrees, for which no pathologic cause can be determined. The initial assessment of adolescents with scoliosis focuses on identification of any treatable underlying pathology. Adolescents with scoliosis typically are asymptomatic and have normal neurologic and physical examinations, with the exception of curvature of the spine. Treatment strategies are determined by the risk of progression. This risk depends on the extent of the curvature and anticipated future spinal growth. The extent of the curvature may be estimated by use of a scoliometer and verified by calculation of the Cobb angle on radiographic evaluation. Skeletal maturity may be estimated by several methods, including radiologic estimates of ossification by bone atlas or Risser sign. Treatment strategies include bracing and surgery.

Adolescent↗
PubMed1996

Common elbow fractures in children.

Approximately 75 percent of all fractures sustained by children occur in the upper extremities and frequently occur during a fall onto an outstretched hand. The majority of these injuries involve the wrist and forearm, but the elbow alone accounts for approximately 10 percent of all fractures in children. Elbow fractures in children are challenging because of the abundance of unossified cartilage and the high potential for limb-threatening damage to neurovascular structures. Common types of elbow fractures include supracondylar, lateral condylar, medial epicondylar, radial neck and transphyseal fractures.

Adolescent↗
PubMed1994

Pedicle screw placement with intraosseous endoscopy.

This study was undertaken to evaluate the efficiency of intraosseous endoscopy for the insertion of pedicle screws. Adult sheep served as an animal model. Under general anesthesia, the authors exposed the posterior lumbar elements through a midline spinal approach and cannulated six to eight pedicles in each sheep, without the use of radiographic or fluoroscopic guidance. Placement of properly located holes as well as intentionally misdirected holes was attempted. Using the fiber optic endoscope, direct examination of the interior of 22 pedicle screw holes was performed. Nine deliberate and 2 unintentional perforations, for a total of 11 defects in 22 pedicles, were easily recognized. These were confirmed by gross examination after specimens were harvested. Defects as small as 2 mm in diameter, not detected on palpation with a standard probe, were able to be closely inspected. The use of intraosseous endoscopy may serve as a useful adjunct in the placement of pedicle screws.

Animals↗
PubMed1992

Complete posterior sternoclavicular epiphyseal separation. A case report and review of the literature.

A review of the literature shows that fractures of the medial clavicular physis rarely occur. Fractures of the medial clavicular physis was diagnosed in a 14-year-old boy. Bony closure of this physis may not be complete until as late as 25 years of age. Complete fracture-separations of this physis, with posterior displacement into the mediastinum, should be included in the differential diagnosis of children and any young adult patients with an apparent posterior sternoclavicular dislocation.

Adolescent↗