Biomedical subjects

L G Lenke

Publications and source records attributed to L G Lenke.

At least 55 records · Page 3Linked to original sources

PubMed1999

Minimum 5-year results of degenerative spondylolisthesis treated with decompression and instrumented posterior fusion.

STUDY DESIGN: An analysis of consecutive cases of degenerative spondylolisthesis treated by one of two surgeons at a university hospital. OBJECTIVES: To assess at a minimum 5-year follow-up the complication rate, reoperation rate, radiographic results, and patient satisfaction with surgical treatment of lumbar degenerative spondylolisthesis by means of segmental posterior instrumented fusion with decompression. SUMMARY OF BACKGROUND DATA: No reports of minimum 5-year follow-up for surgical treatment of degenerative spondylolisthesis were found in the literature. METHODS: The potential study population consisted of 49 consecutive patients who had undergone no prior surgery for degenerative spondylolisthesis (average age, 66.7 years; range, 52.2-78.7 years) with mean follow-up of 6.5 years (range, 5-10.75 years) who were treated with decompression, autogenous iliac crest bone grafting, intertransverse process fusion, and segmental (pedicle screw) instrumentation. Eight patients had died; the remaining 41 were included in the study sample. Thirty-six (88%) of the 41 patients returned an outcome questionnaire and had current radiographs. RESULTS: There was one case of instrument failure (one broken screw with late fusion), and one superficial infection. There were no neurologic deficits, no pseudarthroses, no recurrent stenosis at the fused segment, and no progression of deformity at the fused level. Five patients had symptomatic adjacent level transition syndromes. There were seven additional currently asymptomatic radiographic transition syndromes. Segmental sagittal Cobb angles were maintained at the fused level (17.7 +/- 8-18.8 +/- 7 degrees). Eighty-three percent reported satisfaction with the procedure, 86% thought their back and leg pain was still significantly better than before surgery, and 77% would have the procedure again if needed. Poor satisfaction (n = 4) was associated with more than four medical comorbidities (P < 0.03). A significant number (12 of 49, 24%) of patients had died or were ill more than 5 years after surgery. CONCLUSIONS: Radiographic transition syndromes were common. Major complications (2%), implant failures (2%), and symptomatic pseudarthroses (0%) were low.

Aged↗

PubMed1999

Process measures and patient/parent evaluation of surgical management of spinal deformities in patients with progressive flaccid neuromuscular scoliosis (Duchenne's muscular dystrophy and spinal muscular atrophy).

STUDY DESIGN: Fifty-four consecutive patients with flaccid neuromuscular scoliosis (33 with Duchenne's muscular dystrophy, 21 with spinal muscular atrophy) who had undergone surgery for their disorder between 1985 and 1995 were sent questionnaires to evaluate function, self-image, cosmesis, pain, pulmonary status, patient care, quality of life, and satisfaction. Forty-eight patients returned the questionnaires. OBJECTIVE: To assess patient/parent satisfaction and clinical/functional ways in which spinal fusion helped or did not benefit these patients and to assess complications and the ultimate radiographic result. SUMMARY OF BACKGROUND DATA: There are only a few reports of results of spinal fusion and segmental instrumentation for flaccid neuromuscular disorders. There are no published reports regarding patient/parent evaluation of the procedure. METHODS: Results of the questionnaire were tallied, graded, and divided into eight categories. The questionnaire was validated by a Cronbach's alpha analysis, a test-retest, and a comparison with questionnaire answers from patients with idiopathic scoliosis. Radiographic data and complications also were accumulated. The follow-up periods after surgery ranged from 2 to 12.6 years (average, 7.8 years). RESULTS: Except for two patients who died within 3 months of surgery, all patients seemed to have benefited from the surgery. Cosmesis, quality of life, and overall satisfaction rated the highest. CONCLUSION: These data indicate that spinal fusion with segmental spinal instrumentation benefits most patients with Duchenne's muscular dystrophy or spinal muscular atrophy with spinal deformities in terms of all categories assessed, even though these diseases have a progressively deteriorating course.

Adolescent↗

PubMed1999

Complications in the adult spinal deformity patient having combined surgery. Does revision increase the risk?

STUDY DESIGN: A comparison of short-term complications (within 6 months after surgery) between primary combined adult spinal deformity (multilevel scoliosis, kyphosis, fixed coronal-sagittal imbalance) surgeries (n = 18) and combined adult spinal deformity revision surgeries (n = 26). OBJECTIVES: To analyze the short-term complications and to determine whether revision status increases the risks of short-term complications in this group of patients. SUMMARY OF BACKGROUND DATA: There is no peer-reviewed article comparing complications of revision to those in primary patients in a group of patients undergoing combined surgery for adult spinal deformity. METHODS: Major and minor complications were analyzed for both patient groups, and demographic data were collected. The demographic data of the two groups were very similar. RESULTS: The major (11.1% vs. 7.8%) and minor (11.1% vs. 11.5%) complications for the two groups (primary vs. revision) were very similar. All patients had combined procedures and all were patients with adult spinal deformity. The wound complications were less in those receiving total parenteral nutrition (2 of 31) than in those without (2 of 13). The group receiving parenteral nutrition was thought to be at higher risk for wound complications. CONCLUSIONS: The risk of major and minor complications within the first 6 months after surgery is not necessarily greater in the revision group than in the primary group of patients with adult spinal deformity who have combined surgeries. Total parenteral nutrition does appear to have a role in many of these patients.

Adult↗

PubMed1999

Comparison of anterior and posterior instrumentation for correction of adolescent thoracic idiopathic scoliosis.

STUDY DESIGN: This was a prospective study of two cohort groups of patients (one group receiving anterior instrumentation and the other posterior instrumentation) receiving treatment for thoracic idiopathic scoliosis. OBJECTIVE: To present the 2-year postoperative results of a prospective multicenter study comparing the use of anterior instrumentation with that of posterior multisegmented hook instrumentation for the correction of adolescent thoracic idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Despite reports of satisfactory results, problems have been reported with posterior systems, including worsening of the lumbar curve after surgery and failure to correct hypokyphosis. Theoretically, the advantages of anterior instrumentation include prevention of lumbar curve decompensation by shortening the convexity of the thoracic curve. In addition, by removing the disc, better correction of thoracic hypokyphosis could be obtained. METHODS: Seventy-eight patients who underwent an anterior spinal fusion using flexible threaded rods and nuts (Harms-MOSS instrumentation, De Puy-Motech-Acromed, Cleveland, OH) were analyzed and compared with 100 patients who underwent posterior spinal fusion with multisegmented hook systems. Parameters of comparison included coronal and sagittal correction, balance, distal lumbar fusion levels, and complication. All patients had idiopathic thoracic curves of King Types II to V. The average age at surgery was 14 years in each group, the average preoperative curve 57 degrees, and the minimum duration of follow-up for all patients 24 months. All data were collected prospectively and analyzed via Epl into statistical analysis (Centers of Disease Control, Atlanta, GA). RESULTS: Average coronal correction of the main thoracic curve was 58% in the anterior group and 59% in the posterior group (P = 0.92). Analysis of sagittal contour showed that the posterior systems failed to correct a preoperative hypokyphosis (sagittal T5 to T12 less than 20 degrees) in 60% of cases, whereas 81% were normal postoperatively in the anterior group. However, hyperkyphosis (sagittal T5 to T12 greater than 40 degrees) occurred after surgery in 40% of the anterior group when the preoperative kyphosis was greater than 20 degrees. Postoperative coronal balance was equal in both groups. An average of 2.5 (range, 0-6) distal fusion levels were saved using the anterior spinal instrumentation according to the criteria used for determining posterior fusion levels in this study. Selective fusion of the thoracic curve (distal fusion level T11, T12, L1) was performed in 76 of 78 patients (97%) in the anterior group as compared with only 18 of 100 (18%) in the posterior group. Surgically confirmed pseudarthrosis occurred in 4 of 78 patients (5%) in the anterior group and in 1 of 100 patients (1%) in the posterior group (P = 0.10). Loss of correction greater than 10 degrees occurred in 18 of 78 patients (23%) in the anterior group and in 12 of 100 patients (12%) in the posterior group (P = 0.01). Implant breakage occurred in 24 patients (31%) of the anterior group and in only 1 patient (1%) of the posterior group. CONCLUSIONS: 1) Coronal correction and balance were equal in both the anterior and posterior groups, even though the anterior group had the majority of curves (97%) fused short or to L1, whereas only 18% were fused short or to L1 in the posterior group. 2) In the anterior group there was a better correction of sagittal profile in those with a preoperative hypokyphosis less than 20 degrees. However, hyperkyphosis (with a mean of 54 degrees) occurred in 40% of those in the anterior group with a preoperative kyphosis of more than 20 degrees. 3) An average of 2.5 lumbar levels can be saved with anterior fusion and instrumentation according to the criteria used for choosing posterior fusion levels in this study. 4) Using the 3.2-mm flexible rod in this study, loss of correction, pseudarthrosis, and rod breakage were unacceptably highe

Adolescent↗

PubMed1999

Severe kyphosis secondary to glucocorticoid-induced osteoporosis in a young adult with Cushing's disease. A case report and literature review.

STUDY DESIGN: A case report and literature review of thoracic hyperkyphosis deformity secondary to glucocorticoid-induced osteoporosis in Cushing's disease. OBJECTIVES: To identify the pathophysiology of glucocorticoid-induced osteoporosis and to outline the diagnosis and treatment options for a patient with severe spinal deformity secondary to unrecognized excess glucocorticoid activity. SUMMARY OF BACKGROUND DATA: Glucocorticoid-induced osteoporosis is seen in patients exposed to supraphysiologic levels of endogenous or exogenously administered glucocorticoids. In these patients, glucocorticoids act to suppress bone formation and increase bone resorption by indirect and direct effects. These patients have a high prevalence of trabecular bone loss, resulting in much higher rates of vertebral body collapse and pathologic fracture and thus causing an increased propensity toward kyphotic spinal malalignment. METHODS: The literature was reviewed and case reports studied. This case report highlights the pathophysiology of the disease process that caused the spinal deformity and the surgical intervention used to correct the kyphotic deformity after the metabolic problem was resolved. RESULTS: This patient has responded well to treatment and surgical intervention to correct a thoracic hyperkyphotic deformity without complication. CONCLUSIONS: Unrecognized endogenous production of glucocorticoids in Cushing's disease should be considered in young adult patients with progressive osteoporotic spinal deformities.

Adenoma↗

PubMed1998

Complications of pediatric thoracolumbar and lumbar pedicle screws.

STUDY DESIGN: This was a retrospective review of 223 consecutive cases (1986-1996) from one institution where 759 thoracolumbar and lumbar pedicle screws were used in the treatment of various pediatric spinal disorders in patients less than 18 years of age. OBJECTIVES: To determine the incidence of short- and long-term (> 2 years follow-up) complications in this group of patients-specifically, complications related to instrumentation and those directly attributable to pedicle screws in these pediatric patients. SUMMARY OF BACKGROUND DATA: Although much has been written regarding the use of pedicle screws in the adult population, no published study has examined complication rates with regard to thoracolumbar and lumbar pedicle screws placed for pediatric spinal disorders. METHODS: A retrospective review of 223 consecutive cases involving 759 pedicle screws placed for a variety of pediatric spinal disorders was performed. Complications were divided into short term and long term (> 2 years follow-up) and into those relating to instrumentation and those relating to pedicle screws specifically. RESULTS: Short-term complication occurred in 5 patients (2.2%) for a total of 17 screws ultimately removed. Only two of these patients had screws removed for lumbar radicular complaints. No residual sequellae resulted. No long-term (> 2 years postoperative) complications were noted. CONCLUSION: Low short- and long-term complication rates specific for pediatric pedicle screws suggests that for properly trained spinal surgeons, pedicle screws fixation in the pediatric population can be performed safely to treat a variety of spinal disorders.

Adolescent↗

PubMed1998

The lordotic effect of the OSI frame on operative adolescent idiopathic scoliosis patients.

STUDY DESIGN: A prospective evaluation of adolescent idiopathic scoliosis patients undergoing operative treatment on the Orthopedic Systems Incorporated (OSI; Jackson) frame. OBJECTIVES: To investigate prospectively thoracic, thoracolumbar, and lumbar sagittal alignments in patients with adolescent idiopathic scoliosis who undergo an instrumented posterior spinal fusion on the OSI frame. SUMMARY OF BACKGROUND DATA: In several studies, it has been shown that patient positioning on various operative frames is an important component of ultimate lumbar sagittal alignment. However, these studies have all concentrated on the lumbar spine, and no sagittal plane alignment data in adolescent idiopathic scoliosis patients have been reported in the thoracic and thoracolumbar junction as it relates to intraoperative positioning, correction maneuvers and correlative postoperative results. METHODS: Thirty-nine patients with operative adolescent idiopathic scoliosis treated with an instrumented posterior spinal fusion on the OSI frame were prospectively evaluated. Standing preoperative, intraoperative, and postoperative long-cassette lateral radiographs were reviewed with regional and segmental Cobb measurements of the thoracic, thoracolumbar junction, and lumbar spine obtained. RESULTS: Thoracic kyphosis (T1-T12) measured +34 degrees before surgery, +28 degrees during surgery, and +30 degrees after surgery, Thus, a statistically significant decrease was noted in thoracic kyphosis secondary to prone positioning on the OSI frame ( P < 0.05). Thoracolumbar spine measurements from T10 to L2 also showed a lordotic trend from +2 degrees before surgery, to -4 degrees during surgery, to -8 degrees after surgery, which was also statistically significant (P < 0.05). Total lumbar lordosis from T12 to S1 remained relatively unchanged from -60 degrees before surgery, to -59 degrees during surgery, to -60 degrees after surgery. However, segmental lumbar lordosis measured from T12 to the lowest instrumented vertebra showed a statistically significant increase in lordosis from -17 degrees before surgery, to -19 degrees during surgery, to -23 degrees after surgery (P < 0.05). Those patients in whom lumbar pedicle screws were used (vs. hooks alone) had the greatest increase in lumbar instrumented lordosis. CONCLUSIONS: Performing adolescent idiopathic scoliosis correction on the OSI frame tends to decrease thoracic kyphosis, increase thoracolumbar lordosis, and increase segmental instrumented lumbar lordosis, while it maintains total lumbar lordosis.

Adolescent↗

PubMed1998

Somatosensory- and motor-evoked potential monitoring without a wake-up test during idiopathic scoliosis surgery. An accepted standard of care.

STUDY DESIGN: This was a retrospective study of 500 patients undergoing corrective surgery between 1987 and 1997 for spinal deformity caused by idiopathic scoliosis. OBJECTIVES: To report the sensitivity and specificity of somatosensory-evoked and neurogenic motor-evoked potentials monitoring and the requirements for an intraoperative wake-up test for all idiopathic scoliosis surgeries at a single institution. SUMMARY OF BACKGROUND DATA: Intraoperative monitoring is recommended for use during corrective spinal surgery. Accepted monitoring standards and requirements for an intraoperative wake-up test are still debated. METHODS: The study group consisted of 500 patients undergoing corrective surgery for idiopathic scoliosis between 1987 and 1997. All patients were monitored using somatosensory-evoked and neurogenic motor-evoked potential techniques, using a standard protocol developed at this institution. RESULTS: The false-positive rate (significant data change without postoperative neurologic deficit) was 0.014% (n = 7). The true-positive rate (degradation of data that met warning criteria, with a corresponding postoperative neurologic deficit) was 0.004% (n = 2). No false-negative results (normal data during with a postoperative neurologic deficit) were seen. The sensitivity of combined somatosensory-evoked and neurogenic motor-evoked potential data in predicting neurologic status was 98.6%, and the specificity of normal data predicting normal findings in a neurologic examination was 100%. CONCLUSION: Combined somatosensory-evoked and neurogenic motor-evoked potentials monitoring during idiopathic scoliosis surgery represents a standard of care that obviates the need for an intraoperative wake-up test when reliable data are obtained and maintained.

Adolescent↗

PubMed1998

In vivo Bcl-2 oncogene neuronal expression in the rat spinal cord.

STUDY DESIGN: An acute mechanical rat spinal cord injury model was used to investigate in vivo Bcl-2 oncogene overexpression in neuronal tissue. OBJECTIVES: To introduce the Bcl-2 oncogene in vivo by a recombinant adenovirus vector into rat spinal cord tissue, and to investigate any potential protective effect on neural tissue in the zone of injury in a rat spinal cord model. SUMMARY OF BACKGROUND DATA: The Bcl-2 oncogene inhibits apoptotic and necrotic neural cell death in vitro by regulating an antioxidant pathway at sites of free radical generation. Thus, overexpression of the Bcl-2 oncogene may have a role in limiting the secondary injury cascade of spinal cord injury through its regulation of antioxidants. METHODS: After confirmation of Bcl-2 gene expression in vitro and in vivo in the rat spinal cord, a weight-drop spinal cord injury model was performed on seven rats with prior Bcl-2 inoculation, and on seven rats with prior B-gal inoculation (controls). RESULTS: In vivo Bcl-2 expression was documented by immunostaining. After spinal cord harvest, quantification of percentage preserved tissue at the spinal cord injury site suggested that Bcl-2 overexpression confers neuroprotection. CONCLUSIONS: In vivo Bcl-2 oncogene overexpression was successfully induced in neuronal tissue. After Bcl-2 oncogene expression in the rat spinal cord, the zone of microscopic injury was diminished. Further investigation of the Bcl-2 oncogene for potentially enhancing neuronal survival after spinal cord injury appears indicated.

Adenoviridae↗

PubMed1998

Major intraoperative neurologic deficits in pediatric and adult spinal deformity patients. Incidence and etiology at one institution.

STUDY DESIGN: A retrospective study of 1,090 patients undergoing corrective spinal deformity surgery for scoliosis (n = 920), kyphosis (n = 77), or a combination of the two (n = 93) at one institution. OBJECTIVES: To ascertain the etiologies and incidence of neurologic deficits occurring at the time of surgery. SUMMARY OF BACKGROUND DATA: Potential etiologies of intraoperative neurologic deficits include cord compression, overdistraction, purely vascular, or a combination. METHODS: The study group included only patients with useful function of their lower extremities and normal bowel and bladder control, and patients whose surgeries were in spinal cord territory as opposed to purely cauda equina territory. RESULTS: There were four major neurologic deficits that occurred during surgery. Three of the four deficits were purely vascular in etiology. The fourth may have had a vascular and mechanical etiology. All four patients had anterior and posterior surgery with harvesting of the unilateral convex segmental vessels, and each had a component of hyperkyphosis, as well as intraoperative controlled hypotension. All four patients showed marked improvement of motor weakness with time. CONCLUSIONS: Significant risk factors were combined anterior and posterior surgery (P = 0.009) and hyperkyphosis (P = 0.0006).

Adolescent↗

PubMed1998

Incidence of neural axis abnormalities in infantile and juvenile patients with spinal deformity. Is a magnetic resonance image screening necessary?

STUDY DESIGN: A prospective and retrospective review of patients 10 years and younger with idiopathic scoliosis evaluated with a total spine magnetic resonance imaging (MRI) scan. OBJECTIVES: To determine the incidence of neural axis abnormalities in infantile and juvenile patients with idiopathic scoliosis without neurologic findings on history and examination, to determine the need for a screening MRI in this age group. SUMMARY OF BACKGROUND DATA: In previous studies, a 19.2% and 26% incidence of neural axis abnormalities were found in infantile and juvenile patients with "idiopathic" scoliosis, respectively, raising the question of routine MRI screening of the spinal canal in these patients. METHODS: A prospective study included 34 consecutive patients newborn to 10 years of age treated between 1992 and 1996 at a spinal deformity clinic with idiopathic scoliosis > 20 degrees without neurologic findings. In addition, a retrospective review of 64 patients age newborn to 10 years of age with idiopathic scoliosis was performed. All patients were evaluated by a total spine MRI protocol for examination of neural axis abnormalities. RESULTS: The incidence of neural axis abnormalities in the prospective group of 34 patients was 17.6% (6 of 34); the incidence of neural axis abnormalities was 20.3% (13 of 64) in the retrospective group. Of 6 patients in the infantile age range, 3 (50%) had neural axis abnormalities. CONCLUSIONS: A total spine MRI is recommended at presentation in patients with juvenile onset idiopathic scoliosis (> 20 degrees) because of the high incidence of neural axis abnormalities. Further study appears warranted to establish the incidence of neural axis abnormalities in infantile idiopathic scoliosis to determine the need for total spine MRI screening in this age group.

Arnold-Chiari Malformation↗

PubMed1998

Comparison of standing sagittal spinal alignment in asymptomatic adolescents and adults.

STUDY DESIGN: A retrospective examination of the spine radiographs of 88 asymptomatic adolescents was performed to analyze the indices of regional and segmental sagittal spinal alignment in relation to the sagittal vertical axis as determined by the C7 plumb line. OBJECTIVES: To determine the sagittal spinal alignment in asymptomatic adolescents and to correlate the sagittal vertical axis with the overall sagittal spinal balance and other indices of sagittal spinal alignment. In addition, to compare these results with previously established data for asymptomatic adults. SUMMARY OF BACKGROUND DATA: Previous studies of sagittal spinal alignment have included subjects encompassing a wide range of ages. A previous study at the authors' institution established normative data for sagittal spinal alignment in asymptomatic adults. No previous study has reported on the correlation between the sagittal vertical axis and other measurements of sagittal spinal alignment in asymptomatic adolescents. METHODS: Measurements obtained from the standing lateral spine radiographs of 88 asymptomatic adolescents (age range, 10-18 years) were collected and analyzed using statistical methods. These data were compared with previously established data for asymptomatic adults. RESULTS: There was a striking similarity in regional thoracic kyphosis and lumbar lordosis between adolescents and adults. Despite having similar regional and segmental sagittal alignments, adolescents had a significantly more negative sagittal vertical axis (mean, -5.6 cm) than adults (mean, -3.2 cm; P = 0.0001). Also, unlike that in adults, the sagittal vertical axis in adolescents was not significantly correlated with the distal segmental lumbar lordosis. The sagittal vertical axis in adolescents was significantly correlated with the level of thoracic kyphosis and the distances from the thoracic apex, lumbar apex, and T12 to the C7 plumb line. Sacral inclination, which is a determinant of hip extension and standing pelvic rotation, was correlated with the lumbar apex and the total and segmental lordosis, except at L5-S1. CONCLUSIONS: Asymptomatic adolescents tend to stand in greater negative sagittal spinal balance than asymptomatic adults, despite similar regional and segmental alignments in the thoracic and lumbar spine. The role of hip extension, spinopelvic axis rotation, and other sagittal alignment parameters in determining the sagittal vertical axis in adolescents warrants further study.

Adolescent↗

PubMed1998

Apoptosis as a mechanism of neuronal cell death following acute experimental spinal cord injury.

The complex biochemical interactions following acute spinal cord injury have undergone considerable investigation recently. Progress has been made in discovering both primary and secondary injury cascades that combine to produce the ultimate neurologic insult. Traditionally, neuronal and supporting cell death following spinal cord injury have focused on necrotic death pathways resulting passively from the actual mechanical tissue damage and inflammatory processes which follow. However, the occurrence of programmed apoptotic cell death which is an actively mediated cellular process may occur following acute spinal cord injury and, if present, may play a role in the ultimate neurologic insult. In this study, we document a chronologically-specific course of apoptotic cell death by the TUNEL assay technique following an acute experimental spinal cord injury in the rat model. In this manner, apoptotic cell death following acute spinal cord injury may play a pivotal role in the secondary injury cascade which produces the ultimate neurologic insult and may allow potential for mediating neuronal survival via anti-apoptotic factors such as the protooncogene Bcl-2.

Acute Disease↗

PubMed1998

Radiographic results of arthrodesis with Cotrel-Dubousset instrumentation for the treatment of adolescent idiopathic scoliosis. A five to ten-year follow-up study.

We evaluated the radiographic results of posterior spinal arthrodesis with use of Cotrel-Dubousset instrumentation in seventy-six patients who had adolescent idiopathic scoliosis. At an average of six years (range, five to ten years) postoperatively, the fusion appeared to be solid in all patients. Comparison of radiographs that had been made immediately postoperatively with those that had been made at the time of the latest follow-up showed that no patient had lost any correction in the coronal plane at the levels with instrumentation and seventy-five had had no change in the thoracic or lumbar sagittal alignment at the levels with or without instrumentation. In the remaining patient, a kyphosis had developed at the junction of the segments with instrumentation and those without instrumentation, necessitating additional operative treatment. Sixty-three patients completed a questionnaire for assessment of the clinical status. Their responses were favorable with regard to function, cosmetic appearance, and general satisfaction with the operative result. Twenty-four (38 per cent) of the sixty-three patients reported occasional pain in the spine that did not interfere with work or school activities. Sixty-two patients stated that, given the hypothetical situation of reverting to the preoperative status, they would have the operation again.

Activities of Daily Living↗

PubMed1998

Intraobserver and interobserver reliability of the classification of thoracic adolescent idiopathic scoliosis.

The system described by King et al. is the standard method for the classification of thoracic adolescent idiopathic scoliosis. Although it is widely used and referenced, its reliability and reproducibility among scoliosis surgeons are unknown. We used a scoliosis case-presentation format to examine the interobserver and intraobserver reliability of the classification of thoracic adolescent idiopathic scoliosis with the system of King et al. Eight active, current members of the Scoliosis Research Society reviewed twenty-seven full-length radiographs that had been made before operative correction of the scoliotic deformity. On the basis of these images, which included posteroanterior and lateral radiographs made with the patient standing as well as right and left forced-side-bending radiographs made with the patient supine, the reviewers assigned a type to each curve according to the classification system of King et al. Kappa coefficients were used to test statistical reliability. The mean interobserver reliability of the classification was only 64 per cent (range, 54 to 77 per cent) when the responses of seven of the reviewers were compared with those of one of the originators of the classification. The mean kappa coefficient was 0.49 (range, 0.27 to 0.73), which indicates poor reliability. When each reviewer's responses were compared with those of the other reviewers, the reliability was similarly poor (interobserver reliability, 55 per cent [range, 33 to 81 per cent] and mean kappa coefficient, 0.40 [range, 0.21 to 0.63]). Intraobserver reliability was evaluated in a trial in which five reviewers in a group setting were shown the same radiographs in a different order at two different viewings. Comparison of the results at the two viewings revealed a mean intraobserver reliability of 69 per cent (range, 56 to 85 per cent) and a mean kappa coefficient of 0.62 (range, 0.34 to 0.95), which indicates fair reliability. The current method of classification of adolescent idiopathic scoliosis does not appear to have sufficient intraobserver or interobserver reliability among scoliosis surgeons to portray curve types accurately. Thus, it may not help to guide treatment with use of modern spinal fixation methods.

Adolescent↗

PubMed1998

Neurogenic motor evoked potentials: a prospective comparison of stimulation methods in spinal deformity surgery.

Neurogenic motor evoked potentials (NMEPs) elicited by spinal cord stimulation via the spinous processes (SP-NMEP) have been widely accepted as a sensitive method of monitoring motor tract function. SP-NMEP requires additional surgical dissection as well as electrodes within the wound, making the method somewhat inconvenient. A less invasive percutaneous method of spinal cord stimulation (PERC-NMEP) has more recently been described. We prospectively compared the SP-NMEP and PERC-NMEP methods in 184 patients undergoing 225 surgical procedures. Although SP-NMEP responses were more readily obtainable than PERC-NMEP, the reliability of the two methods was not significantly different. Both methods were found to be sensitive to neurologic deficit. The present study suggests that when responses are obtained, the percutaneous method is reliable enough to obviate the spinous process method of monitoring the motor function of the spinal cord.

Adolescent↗

PubMed1997

Posterior arthrodesis in the skeletally immature patient. Assessing the risk for crankshaft: is an open triradiate cartilage the answer?

STUDY DESIGN: Thirty-three skeletally immature patients younger than 12 years of age and having posterior arthrodesis and evidence of solid posterior fusion without "adding on" were retrospectively reviewed. All patients had a minimum of 5 years of follow-up. OBJECTIVES: To ascertain factors associated with crankshaft and to determine how accurate a marker the triradiate cartilage was. SUMMARY OF DATA: All patients had Risser Stage 0 curves and all of the girls were premenarchal preoperatively. The average age was 9 years 3 months (range, 2 years-11 years 11 months). Preoperative diagnoses consisted of 14 idiopathic, 11 congenital, five dysplastic, and three neuromuscular etiologies. METHODS: Preoperatively, within 3 months after surgery, and at 2-year, 5-year, and final postoperative follow-up, the following radiographic parameters were reviewed: coronal Cobb, apical vertebral rotation, apical vertebral translation, rib vertebral angle difference, and trunkshift. RESULTS: The triradiate cartilage was open in 24 patients at the time of operation. Of those 24, only nine (37.5%) had documented proof of crankshaft. Patients with closed triradiate cartilage had no significant postoperative increase in radiographic parameters (0 of 9). The subgroup of patients with idiopathic scoliosis had an average age of 11 years 3 months (range, 9 years 2 months-11 years 11 months). Five of 14 patients had an open triradiate cartilage. All were followed up to skeletal maturity. None had significant progression in postoperative radiographic parameters. CONCLUSION: This study did not find an open triradiate cartilage to be an absolute prognostic indicator for the occurrence of crankshaft. Additional refinement of markers of maturity are needed to determine who requires anterior arthrodesis.

Cartilage, Articular↗

PubMed1996

The use of pedicle screw fixation to improve correction in the lumbar spine of patients with idiopathic scoliosis. Is it warranted?

STUDY DESIGN: A retrospective assessment of coronal, sagittal, and axial correction using convex lumbar pedicle screw constructs compared with hook constructs in patients with idiopathic scoliosis. OBJECTIVE: To determine if pedicle screw constructs can improve coronal, sagittal, and axial correction without increased complications and therefore warrant their use in the lumbar spine. SUMMARY OF BACKGROUND DATA: Although hooks have been the traditional fixation choice for posterior scoliosis correction of the lumbar spine, pedicle screws may offer advantages for improved correction of lumbar spinal deformity. METHODS: Twenty-two patients constituted Group A (hooks), in which 17 were double major and five were King Type IV curves. These patients had a minimum follow-up period of 2 years and an average of one hook per lumbar fusion segment. Twenty-two patients constituted Group B (screws), in which 20 were double major and two were King Type IV curves. These patients had a minimum follow-up period of 2 years, and screw configuration consisted of pedicle fixation on the convex side for correction and at times on the concave side for fixation. RESULTS: Pedicle screw fixation constructs had improved lumbar Cobb correction (P < 0.05), lowest instrumented vertebra tilt (P < 0.05), lowest instrumented vertebra translation (P < 0.01), and segmental sagittal alignment from T12 to lowest instrumented vertebra (P < 0.01). There was no significant change in axial rotation using either surgical method. CONCLUSIONS: The use of pedicle screw fixation on the convex portion of the lumbar spine in patients with double major idiopathic scoliosis allows for improved correction of the lumbar Cobb measurement, horizontalization and translation of the lowest instrumented vertebra, and improved segmental lordization over the instrumented levels without increased complications.

Adolescent↗