Biomedical subjects

L G Lenke

Publications and source records attributed to L G Lenke.

At least 37 records · Page 2Linked to original sources

PubMed2000

Prospective pulmonary function evaluation following open thoracotomy for anterior spinal fusion in adolescent idiopathic scoliosis.

STUDY DESIGN: Prospective study. OBJECTIVES: To prospectively evaluate sequential pulmonary function tests (PFTs) at a minimum 2-year follow-up after an open anterior spinal fusion (ASF) with instrumentation for thoracic AIS. SUMMARY OF BACKGROUND DATA: Anterior spinal fusion with instrumentation is currently undergoing evaluation as an alternative to posterior spinal fusion (PSF) for thoracic adolescent idiopathic scoliosis (AIS). However, the effect of an open thoracotomy on pulmonary function in these patients is unknown. METHODS: Fifty-one patients with thoracic AIS with an average age of 15+0 (range 11+2 to 20+5) had PFTs consisting of volume (FVC), flow (FEV-1), and total lung capacity (TLC). Parameters were obtained preoperatively, and at 3 months, 1 year, and a minimum 2-year follow-up. All patients had a single or double open thoracotomy with the diaphragm kept intact. Fusion levels ranged from T4 (most proximal) to L1 (most distal). The average preoperative thoracic coronal Cobb measurement was 53 degrees (range 38 degrees to 80 degrees ), and the average postoperative coronal measurement was 24 degrees (range 7 degrees to 49 degrees ). The average preoperative thoracic sagittal kyphosis (T5-T12) averaged 22 degrees (range 10 degrees to 58 degrees ), and the average postoperative sagittal kyphosis measured 29 degrees (range 7 degrees to 67 degrees ). RESULTS: There was a significant decline (P< or =0.05) in PFT absolute values (L) of 19%-FVC, 15%-FEV-1, and 11%-TLC at 3 months postoperatively with subsequent improvement and no statistical difference between preoperative and 2-year postoperative values. When evaluating percent predicted values, there was a statistical decline (P< or =0.05) at 3 months postoperatively averaging 19% FVC, 14% FEV-1, and 12% TLC. These values returned to within 94% to 96% of baseline by the 2-year follow-up visit, but were still statistically less than the preoperative values (P</=0.05). CONCLUSIONS: Pulmonary function following thoracotomy with ASF with instrumentation demonstrated a significant decline of 3-month postoperative PFT values, but returned to preoperative baseline absolute values (L) by the 2-year follow-up visit. The percent predicted values returned to within 95% of baseline 2 years postoperatively. Scoliosis surgeons should be aware of these findings when deciding upon the approach (anterior versus posterior) utilized for thoracic AIS.

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↗

PubMed2000

Analysis of titanium mesh cages in adults with minimum two-year follow-up.

STUDY DESIGN: This is a study of 66 consecutive adult patients (ages 20-81 years) with sagittal deformities who underwent surgery in which structural titanium mesh cages were implanted into the anterior column during posterior instrumentation and fusion. Follow-up ranged from 24 to 62 months (mean, 33 months). OBJECTIVES: To assess the complications and outcomes of patients with structural cages implanted into the anterior column. SUMMARY OF BACKGROUND DATA: Structural cages for the anterior column are popular in the treatment of adult spinal disorders. Few studies to determine their efficacy have a minimum 2-year follow-up. METHODS: Sixty-six patients with minimum 2-year follow-up were analyzed for cage, spinal fusion, and instrumentation status. Outcomes were assessed by analysis of responses to questionnaires administered to the patients at latest follow-up. RESULTS: No cage failure or extrusion was observed. The average segmental improvement in lordosis with cage implantation was 11 degrees with a loss of correction of less than 1 degrees at latest follow-up. The readability of plain radiographs for assessment of anterior fusions was better than for posterior fusions. The agreement level for judging spines to be fused was two of three for 78% of the anterior levels and 47% of the posterior levels. The remaining posterior fusion levels were unassessable. No statistical difference was found in outcome between the group of patients with suspected nonfused anterior levels and the group with all levels fused. CONCLUSIONS: Structural titanium mesh cages implanted into the anterior column function appropriately to maintain sagittal correction, with rare radiographic complications. Seventy-eight percent of the anterior levels were judged to be fused by observers examining plain radiographs. The outcome at latest follow-up for patients with suspected nonfused anterior levels was similar to that in the group of patients with fusions rated solid at every level.

Adult↗

PubMed2000

The effect of variation in arm position on sagittal spinal alignment.

STUDY DESIGN: A prospective radiographic analysis of sagittal alignment in patients with and without previous spinal fusion. OBJECTIVES: To evaluate the effect of variation of arm position on the segmental, regional, and global sagittal radiographic spinal alignment. In addition, to determine whether spinal fusion has any influence on the effect of variation in arm position on the sagittal spinal alignment. SUMMARY OF BACKGROUND DATA: Importance of segmental, regional, and global sagittal alignment has been widely promoted. However, no mention has been made of arm positioning during a lateral spinal radiograph and the resultant effects it may have on sagittal alignment and balance. METHODS: Prospective evaluation of 40 consecutive patients with and 40 consecutive patients without a previous spinal fusion was performed. The patients had lateral long cassette radiographs performed in a standardized fashion with the first radiograph obtained with the patient's arms raised horizontally forward at 90 degrees of flexion at the shoulder, and the second radiograph obtained with arms raised horizontally forward at 30 degrees of flexion at the shoulder. Standard segmental, regional, and global sagittal alignments were measured and statistically compared. RESULTS: In comparing group 1 (patients with spinal fusion) to group 2 (patients without spinal fusion), there was no statistically significant difference in segmental and regional sagittal alignments. However, positioning the arms at 90 degrees versus 30 degrees resulted in a negative shift of the sagittal vertical axis (SVA) in patients that was statistically significant (P = 0.038) for those with (-6 mm at 90 degrees vs +4 mm at 30 degrees ), but not (P = 0.119) for those patients without (-8 mm at 90 degrees vs -4mm at 30 degrees ) a previous spinal fusion. CONCLUSIONS: Based on the findings in this study, the authors recommend positioning the arms at 30 degrees of forward flexion from the vertical when obtaining a long cassette lateral radiograph of the entire spine.

Adolescent↗

PubMed2000

Do radiographic parameters correlate with clinical outcomes in adolescent idiopathic scoliosis?

STUDY DESIGN: A radiographic assessment has been developed to include coronal, sagittal, and axial parameters. OBJECTIVE: To determine the correlation of postoperative radiographic results and percentage postoperative radiographic improvement with patient clinical self-assessment. SUMMARY OF BACKGROUND DATA: With the increasing interest in outcome studies, the authors wanted to determine whether Scoliosis Research Society clinical questionnaire results would correlate with objective radiographic improvement. METHODS INCLUSION CRITERIA: adolescent idiopathic scoliosis treated with anterior or posterior instrumentation, a solid fusion, minimum 2-year follow-up, and a completed postoperative Scoliosis Research Society questionnaire. Seventy-eight patients met the criteria. Measurements included in the radiographic score: Cobb angles of the coronal curve, C7 to the center sacral vertical line, apical translation, apical vertebral rotation, T1 rib angle, end-instrumented vertebrae angulation, angulation of the disc below the end-instrumented vertebra, and curve type. Sagittal measurements included T2-T12, T5-T12, T2-T5, T12-L2, and L1-S1. RESULTS: The preoperative radiographic score of these 78 patients was mean 60.1 +/- 9.7 (range 41-88, maximum radiographic score, 100). The 2-year postoperative radiographic score was mean 83.8 +/- 8.8 (range, 65-100). The median Scoliosis Research Society questionnaire score was 98 +/- 12.3 (range, 58-116, maximum score, 125, showing that the patient is highly satisfied and asymptomatic). The postoperative radiographic score versus the questionnaire score showed a Spearman rank correlation of 0.04 (P = 0.68, little or no correlation throughout). Percentage improvement of the radiographic score versus the questionnaire score showed a Spearman rank correlation of 0.1 (P = 0.38, little or no correlation throughout). CONCLUSION: In this initial group of patients, the radiographic assessment shows a significant improvement between preoperative and 2-year postoperative scores. However, little correlation between the radiographic assessment and the questionnaire scores was found in this adolescent population, suggesting that separate analyses of radiographic and clinical outcome data are required when evaluating results of postoperative scoliosis surgery.

Adolescent↗

PubMed2000

The effect of continued posterior spinal growth on sagittal contour in patients treated by anterior instrumentation for idiopathic scoliosis.

STUDY DESIGN: Retrospective analysis of radiographs on a prospective cohort of patients undergoing anterior instrumentation for thoracic idiopathic scoliosis. OBJECTIVES: To analyze the change in sagittal profile after growth. SUMMARY OF BACKGROUND DATA: The authors previously reported some advantages of anterior instrumentation for treatment of thoracic idiopathic scoliosis. However, postsurgery hyperkyphosis has resulted in some patients, especially those who were skeletally immature at the time of surgery. METHODS: Inclusion criteria required that participants have thoracic idiopathic scoliosis treated with anterior instrumentation and a confirmed solid fusion, no rod breakage, and a minimum follow-up period of 2 years. The 47 patients meeting the criteria were divided into a study group of 10 patients who were Risser 0 at the time of surgery and a control group of 37 patients who were Risser 1 to 5. Progressive sagittal kyphosis was defined as an increase of 10 degrees or more (T5-T12) after surgery. RESULTS: Sagittal progression greater than 10 degrees (average, 15 degrees ) occurred in 6 of 10 patients (60%) in the study group (Risser 0). Five patients progressed from 10 degrees to 19 degrees, and one patient from 20 degrees to 30 degrees. In contrast, sagittal progression occurred in only 10 of 37 patients (27%) in the control group (Risser 1 to 5). CONCLUSIONS: Some patients with thoracic adolescent idiopathic scoliosis treated with anterior instrumentation may be at risk for progressive sagittal kyphosis secondary to growth. Skeletal immaturity (Risser 0) appears to be a risk factor. In these immature patients, preserving the sagittal profile with intervertebral spacers, rigid rods, and bone graft (allowing for an average 15 degrees increase of kyphosis with growth) may be appropriate.

Adolescent↗

PubMed2000

Prospective functional evaluation of the surgical treatment of neurogenic claudication in patients with lumbar spinal stenosis.

A prospective evaluation of patients with lumbar spinal stenosis undergoing operative treatment was performed using treadmill-bicycle functional testing as well as Oswestry and Visual Analog Pain scales for self-assessment. Thirty-two patients undergoing spinal stenosis decompression with and without a concomitant spinal fusion were prospectively evaluated, preoperatively and a minimum of 2 years postoperatively. Surgical treatment was demonstrated to produce significant improvement in walking ability, and to a lesser degree, in the ability to bicycle 2 years postoperatively. Improvement in patient function demonstrated on the Oswestry questionnaire correlated with decreased pain observed on the Visual Analog Pain scale. The treadmill-bicycle test appears to be a useful tool for the differential diagnosis of neurogenic claudication and may be used as an objective test of postoperative outcome.

Adult↗

PubMed2000

Isolated thoracolumbar and lumbar hyperlordosis in a patient with cerebral palsy.

A severe isolated thoracolumbar and lumbar hyperlordosis spinal deformity occurring in a patient with cerebral palsy is rare and has not been reported before. The authors describe the presentation, operative considerations, and treatment of patients with this unusual hyperlordotic spinal deformity, particularly those with cerebral palsy. A multiple-stage surgical reconstruction was required to correct this complex spinal deformity. The patient underwent bilateral femoral extension osteotomies along with spinal extensor myotomies to ensure proper prone positioning for his anticipated spinal surgery. Then he had staged anterior releases and spinal fusion from T8 to the sacrum followed by 2 weeks of "90-90" femoral skeletal traction. Finally, a posterior spinal fusion with instrumentation from T2 to the pelvis definitively corrected his deformity. The patient responded well to surgical intervention without complications and continues to have stable correction of his hyperlordosis deformity 2 years after surgery. Severe lordotic sagittal plane spinal deformities can be treated with anterior and posterior spinal fusion and instrumentation with intervening traction in the properly selected and prepared patient who has cerebral palsy.

Adolescent↗

PubMed2000

Radiographic assessment of anterior titanium mesh cages.

Carbon fiber and titanium cage implantation for anterior column support during spinal fusions is an alternative to the use of more traditional structural allografts and autografts. The authors report instrumentation and cage failure for patients who underwent spinal fusion with structural titanium mesh cages implanted into the anterior column a minimum of 2 years after surgery. They wanted to determine whether plain radiographic techniques can be used to critically assess disk space and corpectomy fusions after implantation of these radioopaque cages. Fifty patients having undergone spinal fusions using structural titanium mesh cages in the anterior column had 99 anterior levels fused with at least 1 (maximum of 2) titanium mesh cage, resulting in a total of 131 cages used. The cages were examined for evidence of settling, migration, or failure. The anterior and posterior instrumentation was assessed for evidence of failure, and the spine was examined for evidence of successful fusion. Radiographic cage settling (>2 mm) into the vertebral body end plates was observed, but cage migration or failure were not. An average lordotic correction of 10 degrees was observed, with loss of correction into kyphosis from immediately after operation to final follow-up averaging 2 degrees. As an average of all reviewers, using a strict radiographic fusion assessment, definite or probable anterior fusion was graded at 81% of the levels, probably not or no at 5% of the levels, and could not be assessed at 14% of the levels. Definite or probable posterior fusion as an average of all reviewers was graded at 44% of the posterior fusion levels, questionable at 4%, no at 5%, and could not be assessed at 47%. The use of anterior-only, posterior-only, or anterior and posterior instrumentation with structural titanium mesh cages in the anterior spine along with proper autogenous bone grafting techniques provided anterior column support with a low rate of radiographic complications. Acceptable anterior spinal fusion rates, as assessed by a consensus agreement of reviewers, were observed primarily by evaluation of the fusion mass around the cages (extracage fusion), because intracage fusion was difficult to assess.

Adolescent↗

PubMed2000

Comparison of push-prone and lateral-bending radiographs for predicting postoperative coronal alignment in thoracolumbar and lumbar scoliotic curves.

STUDY DESIGN: A comparative evaluation of supine right and left lateral-bending radiographs and push-prone radiographs in patients with thoracolumbar and lumbar scoliosis to determine postoperative correction of the curve. OBJECTIVES: To determine the difference in the ability of the push-prone radiograph and the supine lateral-bending radiograph to predict postoperative coronal alignment for primary thoracolumbar and lumbar curves managed with an anterior spinal instrumentation and fusion. SUMMARY OF BACKGROUND DATA: Right and left supine side-bending radiographs are the standard means of evaluating curve flexibility before surgery in idiopathic scoliosis. A push-prone radiograph also has been obtained at the authors' institution as a single dynamic radiographic assessment of forced correction of the primary curve and resultant effects on compensatory curves above and below the fusion. METHODS: Preoperative standing, supine right and left lateral-bending, and push-prone radiographs were performed in 40 patients who underwent anterior spinal instrumentation and fusion. Postoperative standing radiographs of the spine were obtained at 3 months after surgery. Measurements on all the radiographs included the coronal Cobb angle, the angle of the lowest instrumented vertebra to the horizontal, the rotation of the lowest instrumented vertebra, and the distance of the midpoint of the lowest instrumented vertebra from the center sacral line. RESULTS: The lateral-bending and the push-prone radiographs predicted less correction of the Cobb angle and the angle of the lowest instrumented vertebra to the horizontal than was achieved after surgery. However, the push-prone radiograph was superior to the lateral-bending radiograph in accurately predicting the postoperative correction of the rotation of the lowest instrumented vertebra as well as the translation of the lowest instrumented vertebra from the center sacral line. CONCLUSIONS: The push-prone and lateral-bending radiographs are similar in predicting less correction of the Cobb angle after anterior spinal surgery. The push-prone radiograph helps in determining the effects that correction of the primary curve has on the curves above and below the level of fusion by better predicting the translational correction of the lowest instrumented vertebra and the rotation of the lowest instrumented vertebra.

Adolescent↗

PubMed2000

A prospective evaluation of pulmonary function in patients with adolescent idiopathic scoliosis relative to the surgical approach used for spinal arthrodesis.

STUDY DESIGN: A prospective evaluation of pulmonary function in patients with adolescent idiopathic scoliosis undergoing surgical correction. OBJECTIVES: 1) To evaluate prospectively, at regular intervals, the changes in pulmonary function after surgical arthrodesis of primary thoracic and double primary thoracic-lumbar (double major) types of adolescent idiopathic scoliosis in a homogeneous population; 2) to compare the changes in pulmonary function after surgical correction relative to the surgical approach used for spinal arthrodesis; and 3) to determine if short- to midterm morbidity with respect to pulmonary function is associated with the type of surgical approach used for spinal arthrodesis. SUMMARY OF BACKGROUND DATA: The effect of surgical correction on the pulmonary function of patients with adolescent idiopathic scoliosis is controversial. Studies have shown improvement, decline, or no change in pulmonary function after surgical correction of idiopathic scoliosis. METHODS: Ninety-eight patients with adolescent idiopathic scoliosis undergoing surgical treatment at the authors' institution were prospectively evaluated with pulmonary function tests assessing volume (forced vital capacity and total lung capacity) and flow (forced expiratory volume in 1 second). Pulmonary functions were evaluated before surgery and after surgery at 3 months, 1 year, 2 years, and at the final follow-up visit. All patients were divided into four groups depending on the surgical approach used for spinal fusion: Group 1 (n = 47) underwent a posterior spinal fusion with iliac crest bone graft; Group 2 (n = 33) underwent a posterior spinal fusion with rib resection thoracoplasty; Group 3 (n = 7) underwent an anterior spinal fusion with a rib resection thoracotomy; and Group 4 (n = 11) underwent a combined anterior and posterior spinal fusion with autogenous rib and iliac crest graft used, respectively. RESULTS: Patients in Group 1 had improved pulmonary function values at 3 months after surgery, whereas patients in Groups 2, 3, and 4 showed a decline at 3 months after surgery. Two years after surgery, Group 1 had significantly improved pulmonary function values (P < 0.0001), whereas the pulmonary function values of patients in Groups 2, 3, and 4 had returned to preoperative values. CONCLUSIONS: 1) Patients with chest cage disruption during surgical treatment showed a decline in pulmonary function at 3 months after surgery. 2) In contrast, patients without chest cage disruption showed an improvement in pulmonary function at 3 months after surgery. 3) Irrespective of the surgical approach used for spinal arthrodesis, postoperative pulmonary function tests (absolute values) returned to preoperative values at 2 years after surgery. 4) Patients who had no chest cage disruption experienced a significantly greater improvement in two of their pulmonary function values at 2 years after surgery than patients with chest cage disruption.

Adolescent↗

PubMed2000

The effect of nerve-root injections on the need for operative treatment of lumbar radicular pain. A prospective, randomized, controlled, double-blind study.

BACKGROUND: The purpose of the present study was to determine the effectiveness of selective nerve-root injections in obviating the need for an operation in patients with lumbar radicular pain who were otherwise considered to be operative candidates. Although selective nerve-root injections are used widely, we are not aware of any prospective, randomized, controlled, double-blind studies demonstrating their efficacy. METHODS: Fifty-five patients who were referred to four spine surgeons because of lumbar radicular pain and who had radiographic confirmation of nerve-root compression were prospectively randomized into the study. All of the patients had to have requested operative intervention and had to be considered operative candidates by the treating surgeon. They then were randomized and referred to a radiologist who performed a selective nerve-root injection with either bupivacaine alone or bupivacaine with betamethasone. The treating physicians and the patients were blinded to the medication. The patients were allowed to choose to receive as many as four injections. The treatment was considered to have failed if the patient proceeded to have the operation, which he or she could opt to do at any point in the study. RESULTS: Twenty-nine of the fifty-five patients, all of whom had initially requested operative treatment, decided not to have the operation during the follow-up period (range, thirteen to twenty-eight months) after the nerve-root injections. Of the twenty-seven patients who had received bupivacaine alone, nine elected not to have the operation. Of the twenty-eight patients who had received bupivacaine and betamethasone, twenty decided not to have the operation. The difference in the operative rates between the two groups was highly significant (p < 0.004). CONCLUSIONS: Our data demonstrate that selective nerve-root injections of corticosteroids are significantly more effective than those of bupivacaine alone in obviating the need for a decompression for up to thirteen to twenty-eight months following the injections in operative candidates. This finding suggests that patients who have lumbar radicular pain at one or two levels should be considered for treatment with selective nerve-root injections of corticosteroids prior to being considered for operative intervention.

Anesthetics, Local↗

PubMed1999

Maintaining lumbar lordosis with anterior single solid-rod instrumentation in thoracolumbar and lumbar adolescent idiopathic scoliosis.

STUDY DESIGN: A prospective radiographic evaluation of 20 consecutive patients with primary lumbar or thoracolumbar adolescent idiopathic scoliosis who were treated with anterior convex compressive single solid-rod spinal instrumentation and structural titanium mesh (Harms) cages. OBJECTIVES: To evaluate a lordosis-preserving anterior single solid-rod instrumented fusion technique for these specific adolescent idiopathic curves. SUMMARY OF BACKGROUND DATA: Maintaining instrumented segmental lumbar lordosis after anterior fusion and instrumentation for thoracolumbar and lumbar curves has been difficult. Twenty consecutive patients who underwent anterior single solid-rod fusion, aged 18 or younger with a primary thoracolumbar or lumbar curve, were observed for preservation of lordosis for a minimum of 2 years. METHODS: All patients underwent an identical anterior surgical technique, involving discectomies and anulectomies of all convex discs, structural titanium mesh (Harms) cages placed in the anterior half of all disc spaces below T12, morselized rib autograft packed in all disc spaces to be fused and inside the cages, and anterior single solid-rod (5.0-mm or 5.5-mm diameter) convex compressive spinal instrumentation with appropriate lordotic rod contour and rod rotation as necessary. The anterior rod was placed just posterior to the cages to optimize lordotic contouring of the spine during compression. None of the patients was braced after surgery. The lowest instrumented vertebrae (LIV) were L2 (n = 3), L3 (n = 15), and L4 (n = 2), typically the lower end vertebra of the Cobb measurement. RESULTS: Measurements for the primary coronal Cobb before surgery, 1 week after surgery, and 2 years after surgery were 48 degrees, 11 degrees, and 12 degrees; for C7 plumb line deviation from the midline: 3.6 cm, 1.9 cm, and 1.2 cm; for lowest instrumented vertebra translation: 31 mm, 15 mm, and 15 mm; and for LIV tilt: 29 degrees, 6 degrees and 6 degrees, respectively. Sagittal measurements before surgery, 1 week after surgery, and 2 years after surgery were: T12-L2: -1 degree, -6 degrees, and -6 degrees; T12-LIV: -8 degrees, -13 degrees, -9 degrees; T12-S1: -61 degrees, -56 degrees, -60 degrees; and entire instrumented levels: -6 degrees, -9 degrees, and -6 degrees, respectively. Coronal plane correction improved: 75% in the primary Cobb, 66% in the plumb line, 50% in LIV translation, and 80% in LIV tilt. Sagittal plane alignment improved in T12-L2 lordosis (P < 0.01) with preservation of physiologic lordosis in the instrumented levels, T12-LIV, and T12-sacrum. There were no instrumentation failures, pseudarthroses, or reoperations. CONCLUSIONS: Coronal plane correction with preservation of thoracolumbar and lumbar lordosis 2 years after anterior convex compressive spinal instrumentation was accomplished using a lordotically contoured single solid rod with structural cages placed anteriorly in the disc spaces of patients with primary thoracolumbar or lumbar adolescent idiopathic scoliosis.

Adolescent↗

PubMed1999

Spontaneous lumbar curve coronal correction after selective anterior or posterior thoracic fusion in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective review of anterior and posterior fusions for treatment of adolescent idiopathic thoracic scoliosis. OBJECTIVES: To evaluate both the instrumented thoracic and the spontaneous lumbar curve corrections after treatment of the primary thoracic scoliosis by either anterior or posterior fusion. SUMMARY OF BACKGROUND DATA: Recent reports of thoracic scoliosis fusions have concentrated on the thoracic correction obtained by posterior segmental instrumentation systems. Coronal decompensation occurring because of curve progression with imbalance of the unfused lumbar spine has also been investigated. No report comparing spontaneous lumbar curve response after selective anterior versus posterior thoracic scoliosis fusions are available. METHODS: One hundred twenty-three cases of primary thoracic-compensatory lumbar adolescent idiopathic scoliosis were treated by selective thoracic instrumentation and fusion with either an anterior (n = 70) or posterior (n = 53) single approach. Thoracic and lumbar Cobb measurements and lumbar apical translation parameters were assessed before surgery, 1 week after surgery, and 2 years after surgery on upright coronal radiographs. All patients had a minimum 2-year follow-up. RESULTS: At 2-year follow-up, the percentage of thoracic curve correction was superior for the anterior (58%) versus the posterior (38%) group (P < 0.05), whereas the spontaneous lumbar curve correction was also superior for the anterior (56%) group versus the posterior (37%) group for all curve types investigated (P < 0.05). Both treatment groups consistently improved lumbar apical positioning after the thoracic fusion procedure. CONCLUSIONS: Spontaneous lumbar curve correction occurs consistently after both selective anterior and posterior thoracic fusion implying intrinsic ability of the lumbar spine to follow thoracic spine correction. In the current study, using multisegmented hook-rod systems posteriorly with intentional limitation of posterior thoracic correction to avoid decompensation, instrumented thoracic and spontaneous lumbar curve correction was statistically better after anterior thoracic instrumentation and fusion, with the results most dramatic for lumbar curve Type C (true King II curves).

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↗

PubMed1999

Complications in the surgical treatment of pediatric high-grade, isthmic dysplastic spondylolisthesis. A comparison of three surgical approaches.

STUDY DESIGN: An analysis of consecutive pediatric patients treated surgically for high-grade spondylolisthesis by one of three surgical procedures with emphasis on complications and functional outcomes. OBJECTIVE: Complications, radiographic results and patient-assessed function, pain, and satisfaction were assessed among three surgical procedures. SUMMARY OF BACKGROUND DATA: The existing literature is in disagreement about whether it is better to fuse without instrumented reduction or to use instrumentation and reduce high-grade dysplastic spondylolisthesis. METHODS: Thirty-two patients had 37 surgical procedures for Meyerding Grade 3 or 4 isthmic dysplastic spondylolisthesis. Eleven patients were treated with an in situ L4-sacrum posterior fusion without decompression (Group 1), 7 had posterior decompression with posterior instrumentation and posterior fusion (Group 2), and 19 patients had reduction and a circumferential fusion procedure (Group 3). All patients had new radiographs taken at time of follow-up (average, 3.1 years; range, 2 years-10 years, 1 month) and completed a functional outcome questionnaire. RESULTS: The incidence of pseudarthrosis was 45% (5 of 11) in Group 1, 29% (2 of 7) in Group 2, and 0% (0 of 19) in Group 3. All seven who had pseudarthrosis had small L5 transverse process surface area (< 2 cm2; P = 0.004). Only one patient had a neurologic deficit (unilateral extensor hallucis longus weakness) at time of follow-up. There were no significant differences among the groups in function, pain, and satisfaction in patients in whom solid fusion was obtained, but the scores were highest in Group 3. CONCLUSIONS: In situ fusion surgery in patients with high-grade spondylolisthesis with small L5 transverse processes (surface area, < 2 cm2) results in a high rate of pseudarthrosis. Circumferential procedures result in the highest rate of fusion and are effective in achieving fusion in those patients with established pseudarthrosis. The use of long (> 60 mm) iliac screws bilaterally (n = 21) in addition to bicortical sacral screws (four-point sacral-pelvis fixation) along with anterior column fusion reduces the risk of instrumentation failure in a decompression and reduction procedure. Outcomes of function, pain, and satisfaction are excellent in those in whom fusion is achieved. The risks in circumferential fusion-reduction procedures are acceptable.

Adolescent↗

PubMed1999

Complications and predictive factors for the successful treatment of flatback deformity (fixed sagittal imbalance).

STUDY DESIGN: This is an analysis of consecutive cases of flatback deformity (fixed sagittal imbalance), treated by one of two surgeons at a university hospital. OBJECTIVE: To define factors that contribute to results with treatment of flatback syndrome, classify types of sagittal deformities, and discuss complications. SUMMARY OF BACKGROUND DATA: There are few reports that detail the results and complications of current instrumentation and osteotomy techniques for correction of fixed sagittal deformities. METHODS: Twenty-eight patients treated with osteotomies for sagittal imbalance were eligible for 2-year minimum follow-up (average, 3.6 years). Patients were classified (segmental imbalance, Type 1; or global imbalance, Type 2) and evaluated by upright radiographs, chart review, and a questionnaire. RESULTS: Twenty-eight (100%) patients returned the questionnaire, and 28 had current radiographs. Five treatment groups were evaluated based on osteotomy type (anterior, posterior [Smith-Petersen], both, or pedicle subtraction) and use of anterior structural grafting. All patients were treated with modern bilateral hook-rod-screw constructs. Mean correction at the osteotomy levels was 25 degrees for Type 1 deformities and 30 degrees for Type 2 (P < 0.05). Sagittal correction averaged 6.6 cm in Type 2 deformities (P < 0.05). Questionnaire analysis showed a significant and persistent reduction in subjective pain level. There were seven patients with 11 total complications and no neurologic deficits. Associations among patients who were not satisfied with their results (n = 4) included insufficient sagittal correction (P = 0.045), pseudarthrosis (P = 0.045), coronal imbalance, and four or more medical comorbidities (P = 0.03). CONCLUSIONS: Satisfaction with the results of treatment may be reduced in patients with four or more major co-existent medical problems, insufficient sagittal correction, and resultant pseudarthrosis.

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