Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “multilevel analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46Linked to original sources
PubMed2000

The Baumann procedure for fixed contracture of the gastrosoleus in cerebral palsy. Evaluation of function of the ankle after multilevel surgery.

We treated 22 children (28 limbs) with diplegic cerebral palsy who were able to walk by the Baumann procedure for correction of fixed contracture of the gastrosoleus as part of multilevel single-stage surgery to improve gait. The function of the ankle was assessed by clinical examination and gait analysis before and at two years (2.1 to 4.0) after operation. At follow-up the ankle showed an increase in dorsiflexion at initial contact, in single stance and in the swing phase. There was an increase in dorsiflexion at initial push-off without a decrease in the range of movement of the ankle, and a significant improvement in the maximum flexor moment in the ankle in the second half of single stance. There was also a change from abnormal generation of energy in mid-stance to the normal pattern of energy absorption. Positive work during push-off was significantly increased. Lengthening of the gastrocnemius fascia by the Baumann procedure improved the function of the ankle significantly, and did not result in weakening of the triceps surae. We discuss the anatomical and mechanical merits of the procedure.

Adolescent↗
PubMed2005

Exploring the spatial pattern of mental health expenditure.

BACKGROUND: Recent years have witnessed growing interest in cross-sectional variations in municipality mental health expenditure. However, empirical work to date has not examined the links between such variability and demand and supply factors, particularly in the spatial domain. AIMS OF THE STUDY: The aim is to examine whether a local authority's spending decisions in the mental health field respond to neighbouring expenditure decisions. We explore a number of reasons why there might be interdependence between local authorities' decisions, labelling them the demonstrative, market leader, contextual, directive, shared resource and inducement effects. METHODS: Exploratory techniques from spatial data analysis are used to test for the existence of spatial structure. Drawing hypotheses from these initial exploratory analyses, we then adopt a reduced form demand and supply model, extended to incorporate possible policy interaction. The analysis of expenditure and cost variations has traditionally been based on regression models under the classical assumption that the observations are independent. But omitting the recognition that observations are interdependent might lead to erroneous statistical conclusions. Hence, we use spatial econometric techniques that explicitly take into account the potential interdependence of data in order to study the sources of spending variation between municipalities. RESULTS: The exploratory data analyses reveal the presence of positive significant spatial correlation. Per capita mental health spending distributes in clusters, with the highest concentrations in metropolitan areas such as Greater London, Greater Manchester and Birmingham. The estimated spatial regression models indicate that spatial autocorrelation characterises local expenditure decisions, consistent with some degree of policy interdependence between neighbouring municipalities. Comparing the results from our spatial model with those from a classical ('non-spatial') model suggests that the differences in the regression coefficients could be explained by the evident spatial pattern of the phenomenon, since the omission of the lagged dependent variable induces bias in the OLS estimates. IMPLICATIONS FOR HEALTH POLICIES: These results help central and local decision makers understand the factors that influence local spending levels, including variations between municipalities in their achievement of expenditure-related and perhaps other performance targets. The actual patterns of spatial interaction may well be more complex than simple contiguity (the structure assumed here), but there seems little doubt that positive interdependence is an important feature of decision making. IMPLICATIONS FOR FURTHER RESEARCH: Statistical interrogation of a panel dataset would allow exploration of both time-series and cross-municipality variation in mental health expenditure. Subsequent analysis would also benefit from more disaggregated data (e.g. at a census ward level) and the accompanying use of spatial multilevel techniques.

Adolescent↗
PubMed2006

The Ross-Konno procedure in children: outcomes, autograft and allograft function, and reoperations.

BACKGROUND: The Ross aortic valve replacement with a modified Konno-type enlargement Ross-Konno procedure of the aortic annulus and subannular region allows an autograft aortic valve replacement for children with significant annular and subannular hypoplasia. The potential for growth and the proven durability of the autograft make the Ross-Konno procedure an ideal aortic valve replacement for this subgroup with multilevel left ventricular outflow tract obstruction. We reviewed our institutional midterm experience to assess autograft and homograft hemodynamics, and management after a Ross-Konno procedure. METHODS: Between 1995 and 2005, 14 consecutive children (mean age, 6.4 +/- 5.9 years; range, 1 month to 17 years) underwent the Ross-Konno procedure. All children had severe to critical aortic stenosis or multilevel left ventricular outflow tract obstruction. RESULTS: There was 1 early and 1 late death with a mean follow-up of 5.7 +/- 3.6 years. Actuarial survival at 10 years was 86%. Three patients underwent right ventricular outflow tract reoperation for conduit replacement for homograft dysfunction and one patient required redo aortic root replacement with a mechanical valves for progressive aortic insufficiency. Freedom from right ventricular outflow tract and autograft reoperation at 10 years is 77% and 92%, respectively. Aortic annular dilation was not observed in all patients. Univariate and multivariate analysis identified no risk factors for autograft or homograft valve-related reoperation. CONCLUSIONS: The Ross-Konno procedure is an excellent technique to treat complex multilevel left ventricular outflow tract obstruction in children with significant annular and subannular hypoplasia. The autograft demonstrated durability without development of aortic stenosis or progressive dilation and a low incidence of developing progressive aortic insufficiency. Enlargement of the aortic annulus appear to parallel somatic growth in most instances.

Adolescent↗
PubMedDate not supplied

From cognition to the system: developing a multilevel taxonomy of patient safety in general practice.

The paper describes the process of developing a taxonomy of patient safety in general practice. The methodologies employed included fieldwork, task analysis and confidential reporting of patient-safety events in five West Midlands practices. Reported events were traced back to their root causes and contributing factors. The resulting taxonomy is based on a theoretical model of human cognition, includes multiple levels of classification to reflect the chain of causation and considers affective and physiological influences on performance. Events are classified at three levels. At level one, the information-processing model of cognition is used to classify errors. At level two, immediate causes are identified, internal and external to the individual. At level three, more remote causal factors are classified as either 'work organization' or 'technical' with subcategories. The properties of the taxonomy (validity, reliability, comprehensiveness) as well as its usability and acceptability remain to be tested with potential users.

Classification↗
PubMed2002

Effect of derotation osteotomy of the femur on hip and pelvis rotations in hemiplegic and diplegic children.

The purpose of this study was to evaluate hip and pelvis rotations in groups of hemiplegic and diplegic children before and after surgical correction of fixed internal rotation deformity of the hip. Twenty-two children with cerebral palsy (eight diplegia, 14 hemiplegia) having fixed internal rotation deformity at the hip were treated by multilevel surgery which included derotation osteotomy of the femur. Evaluation was done before and at a mean of 3.1 years after surgery using three-dimensional computerized gait analysis. Preoperatively, the patients in the hemiplegia group had a significantly greater compensatory external rotation of the pelvis than those in the diplegic group. Post-operatively there were no significant differences between the two groups. In the hemiplegia group the external rotation of the pelvis was corrected after correction of hip rotation by derotation osteotomy. Patients in the diplegia group showed significant improvements in the hip rotation with no significant change in the pelvis rotation after multilevel surgery.

Adolescent↗
PubMed2005

Enrolling older persons in cancer trials: the effect of sociodemographic, protocol, and recruitment center characteristics.

PURPOSE: To determine the effect of patient, protocol, geographic, and institutional factors on enrollment of older persons onto cancer trials. METHODS: We conducted a cross-sectional analysis of patients enrolled onto National Cancer Institute-sponsored lung, breast, colorectal, and prostate cancer trials during 1996 to 2002. We used a cross-classified logistic multilevel model to examine the associations between patient, hospital, county, and protocol characteristics, and the likelihood of participants being elderly (>or= 65 years old). RESULTS: The final study sample consisted of 36,167 patients enrolled onto 33 trials. After accounting for cancer type, only 6% of the variation in elderly enrollment onto cancer trials was at the protocol level. In contrast, more than 55% of the variation in elderly enrollment was attributable to patient level variation. In multivariate analysis, nonwhite patients were significantly less likely to be elderly than whites (odds ratio [OR] for blacks, 0.51; 95% CI, 0.44 to 0.58; and OR for Hispanics, 0.49; 95% CI, 0.40 to 0.59 v whites). Participants living less than 7 miles from their recruitment center were significantly more likely to be elderly (OR, 1.31; 95% CI, 1.24 to 1.38). Among the 910 recruitment centers, the median adjusted proportion of patients who were elderly was 24.9% (interquartile range, 24.0% to 26.9%). There were a significantly higher number of outlier centers ( or= 29.3% elderly) than would be expected by a normal distribution (68 observed v six expected; P < .0001). CONCLUSION: Race and proximity to trial enrollment centers were significantly related to age of trial participants after adjusting for protocol factors. Additional work should explore why some recruitment centers were outliers regarding enrollment of older persons.

Aged↗
PubMed2003

Comprehensive solid-phase extraction method for persistent organic pollutants. Validation and application to the analysis of persistent chlorinated pesticides.

The Centers for Disease Control and Prevention (CDC) is involved in many epidemiological studies regarding the measurement of chlorinated pesticides and polychlorinated biphenyls in specimens obtained from humans. In addition to these commonly determined analytes, there is a need to include additional persistent organic pollutants (POPs) in our analyses, which further stresses the analyses because sample volumes remain small. Thus, a single method of analysis for all POPs in human serum is needed. CDC has recently developed a semiautomated and comprehensive solid-phase extraction method for POPs. The method is comprehensive since it was optimized for the extraction of many different POP compound classes. We then developed a purification and fractionation scheme that allows (a) separation of different compound classes by particular functionalities and (b) purification of those fractions to remove coextracted interferences. This paper describes the first step in the semiautomated comprehensive extraction and multiple fractionation method developed by CDC for monitoring POPs. In this paper, we validate the analysis of the persistent chlorinated pesticides, a compound class difficult to examine because of their structural diversity, in human plasma. The method was validated against an existing CDC method by using a spiked quality-control serum pool. The concentrations determined for all analytes using both methods were within 2%-14% relative standard deviations. A multilevel (i.e., 3-4 point) matrix spike showed good linearity for the analytes tested (r2 = 0.978-0.999). The method was then applied to 40-year-old archived plasma samples for the quantitative analysis of selected chlorinated pesticides. Mean recoveries of the 13C-labeled internal quantification standards ranged from 64% to 123% for the 11 monitored pesticides. The overall method proved to be robust by handling old coagulated plasma samples. It allowed faster throughput of samples than our previous methods and provided cleaner samples with less frequent interferences or background as analyzed by high-resolution mass spectrometry. The method represents a preliminary step in establishing an automated, comprehensive multiresidue analysis method for POPs in human serum.

Automation↗
PubMed2005

Ghrelin, adiponectin, and leptin do not predict long-term changes in weight and body mass index in older adults: longitudinal analysis of the Rancho Bernardo cohort.

Ghrelin, leptin, and adiponectin are associated with body size in cross-sectional studies; it is unknown whether these hormones predict long-term changes in body size. Multilevel models were used to study associations between fasting serum hormones, measured in 698 men and 619 women (60-91 years) in samples collected at baseline (1984-1987), and changes in weight and body mass index, assessed repeatedly over a follow-up period of up to 18 years (median, 4.7 years). Baseline weight was -1.5 kg lower for a one-standard-deviation increment in ghrelin and -3.3 kg lower for a one-standard-deviation increment in adiponectin, similar in men and women. For leptin, baseline weight was 12.1 kg higher for a one-standard-deviation increment in men, compared with 5.7 kg in women (sex-interaction p < or = 0.0001). Ghrelin and adiponectin did not affect weight change; their associations with weight were constant over time, indicated by nonsignificant hormone-by-time interactions. The positive association between leptin and weight became slightly weaker over time. Results were similar when investigating repeated measures of body mass index. From this analysis of Rancho Bernardo Study data, the authors conclude that ghrelin, adiponectin, and leptin do not predict weight gain beyond reflecting the influence of attained body size on future changes in weight or body mass index.

Adiponectin↗
PubMed2005

Comparing objective and subjective status: gender and space (and environmental justice?).

The environmental justice literature has described differential health effects of environmental toxins and pollutants on people of different socio-economic status (SES) that may not always reflect differing levels of exposure. We offer four questions or contentions that together may contribute to understanding this conundrum and then present an empirical exploration of one of these questions: Does the relationship between SES and self-perceived status vary in space? Utilizing data from an original questionnaire survey of randomly selected adults conducted in twenty-five communities in British Columbia, Canada, a supplementary data set containing demographic and socio-economic characteristics of the communities themselves, and multilevel modelling techniques, this article describes relationships between objective and subjective measures of social status, by gender and in space. Our analysis contributes to the development of innovative environmental justice models by bringing some spatial sensitivity to interrelationships among these aspects of status.

Adult↗
PubMed2005

Manufacturers' approaches in the development of intelligent multilevel safety systems to assist perfusionists during cardiopulmonary bypass.

How safe is safe? The design intent of perfusion safety systems is to offer maximum flexibility, low-cost and failsafe features. While easily said, these requirements are difficult to deliver in a perfusion world where standardization is uncommon. This paper reviews the challenges all manufacturers face as they strive to offer the ultimate in safety, keeping the price affordable for the technology deployed and the usability common sense for the perfusionist using the equipment. As microprocessors are able to assist designers in providing intelligent, multilevel safety systems, care must be taken during the design process to balance technological ability with intuitive use. In the final analysis, however, it is the perfusionist who is the primary safety system, and the technology is his or her backup.

Cardiopulmonary Bypass↗
PubMed2004

Multilevel selection and the partitioning of covariance: a comparison of three approaches.

Where the evolution of a trait is affected by selection at more than one hierarchical level, it is often useful to compare the magnitude of selection at each level by asking how much of the total evolutionary change is attributable to each level of selection. Three statistical partitioning techniques, each designed to answer this question, are compared, in relation to a simple multilevel selection model in which a trait's evolution is affected by both individual and group selection. None of the three techniques is wholly satisfactory: one implies that group selection can operate even if individual fitness is determined by individual phenotype alone, whereas the other two imply that group selection can operate even if there is no variance in group fitness. This has significant implications both for our understanding of what the term "multilevel selection" means and for the traditional concept of group selection.

Altruism↗
PubMedDate not supplied

Congenital lumbar spinal stenosis: a prospective, control-matched, cohort radiographic analysis.

BACKGROUND CONTEXT: Degenerative lumbar spinal stenosis manifests primarily after the sixth decade of life as a result of facet hypertrophy and degenerative disc disease. Congenital stenosis, on the other hand, presents earlier in age with similar clinical findings but with multilevel involvement and fewer degenerative changes. These patients may have subtle anatomic variations of the lumbar spine that may increase the likelihood of thecal sac compression. However, to the authors' knowledge, no quantitative studies have addressed various radiographic parameters of symptomatic, congenitally stenotic individuals to normal subjects. PURPOSE: To radiographically quantify and compare the anatomy of the lumbar spine in symptomatic, congenitally stenotic individuals to age- and sex-matched, asymptomatic, nonstenotic controlled individuals. STUDY DESIGN/SETTING: A prospective, control-matched, cohort radiographic analysis. PATIENT SAMPLE: Axial and sagittal magnetic resonance imaging (MRI) and lateral, lumbar, plain radiographs of 20 surgically treated patients who were given a clinical diagnosis of congenital lumbar stenosis by the senior author were randomized with images of 20, asymptomatic age- and sex-matched subjects. OUTCOME MEASURES: MRIs and lateral, lumbar, plain radiographs were independently quantitatively assessed by two individuals. Measurements obtained from the axial MRIs included: midline anterior-posterior (AP) vertebral body diameter, vertebral body width, midline AP canal diameter, canal width, spinal canal cross-sectional area, pedicle length, and pedicle width. From the sagittal MRIs, the following measurements were calculated: AP vertebral body diameter, vertebral body height, and AP canal diameter at the mid-vertebral level. On the lateral, lumbar, plain radiograph (L3 level), the AP diameters of the vertebral body spinal canal were measured. METHODS: The images of these 40 individuals were then randomized and distributed in a blinded fashion to five separate spine surgeons who graded the presence and severity of congenital stenosis utilizing a five-tier scale. Images consisting of 15 symptomatic individuals, graded definitely congenitally stenotic (mean age, 51.7 years; range, 43-65 years), and 15 asymptomatic individuals, graded definitely not stenotic (mean age, 50.7 years; range, 41-55 years), were age- and sex-matched and included for further review. From these 30 patients, a lateral, lumbar, plain radiograph and axial and sagittal MRIs (T1/T2 weighted) from L2-L5 were quantitatively analyzed. Rater reliability was assessed by Kappa coefficient testing. RESULTS: The cross-sectional area of the canal was significantly smaller in the congenitally stenotic patients at all lumbar levels measured (L2: 176 mm(2) vs. 259 mm(2), L3: 177 mm(2) vs. 275 mm(2), L4: 183 mm(2) vs. 283 mm(2), L5: 213 mm(2) vs. 323 mm(2), p<.05). Pedicle length was markedly shorter in the stenosis group at each lumbar level (L2: 5.9 mm vs. 8.9 mm, L3: 6.0 mm vs. 8.8 mm, L4: 6.5 mm vs. 9.2 mm, L5: 5.8 mm vs. 9.1 mm, p<.05). Furthermore, midline, axial AP canal diameter, vertebral body width, and sagittal AP canal diameter were all significantly smaller than the control patients (p<.05). A ratio of the AP diameter of the pedicle length to the vertebral body was also noted to be statistically significant on both the lateral plain radiographs (L3: 0.426 vs. 0.704) and sagittal MRI (L2: 0.343 vs. 0.461, L3: 0.361 vs. 0.461, L4: 0.362 vs. 0.481, L5: 0.354 vs. 0.452, p<.05). No difference was noted comparing the AP diameter of the vertebral body (axial and sagittal images), vertebral body height, canal width, and pedicle width. Kappa testing coefficient indicated a strong rater reliability (k=0.81, 95% confidence interval: 0.62-0.94). CONCLUSIONS: Congenital lumbar stenosis has not been clearly defined radiographically. Clinically, congenitally stenotic patients present at a younger age with fewer degenerative changes and multiple levels of involvement. Radiographically, these patients have a shorter pedicular length and as a result a smaller cross-sectional spinal canal area (mean critical values of 6.5 mm and 213 mm(2) were observed, respectively). The mean critical ratios were 0.43 (2:1 AP vertebral body: pedicle length) on the lateral lumbar radiograph and 0.36 on the sagittal MRI. The altered canal anatomy resulting from a decreased pedicle length may anatomically predispose these patients to earlier complaints of symptomatic neurogenic claudication. Identification of the presence of congenital stenosis should increase the treating surgeon's awareness of the potential need for multilevel treatment.

Adult↗
PubMed2006

Structured correlation in models for clustered data.

Correlation is always a concern in the analysis of clustered data. One area of interest is to develop a general correlation modelling approach for high dimensional data with unbalanced hierarchical and heterogeneous data structures, e.g. multilevel data. Commonly used correlation structures might have limitation for such situations. In this paper, we propose two extensions, multiblock and multilayer correlations. These methods are very flexible in modelling correlation and can be incorporated in many multivariate approaches, while the major discussion focuses on the applications under the generalized estimating equations (GEE) methods. The approaches are especially useful in GEE when each cluster is large and complex but the number of clusters is small. If an incorrect correlation is applied to such data, the results are less efficient. Multiblock and multilayer correlations extend GEE methods to model complicated multilevel data with arbitrary number of levels and cluster size. The extended estimating equation for correlation parameters has an orthogonal property, and the computation is very efficient. A simulation study compares the conventional methods versus the proposed methods, and it shows the gain in relative efficiency and the flexibility in modelling various structures.

Adult↗
PubMed2002

Biomechanical analysis of anterior scoliosis instrumentation: differences between single and dual rod systems with and without interbody structural support.

STUDY DESIGN: Nondestructive biomechanical testing was performed on bovine lumbar spines instrumented with multilevel scoliosis type anterior spine constructs. OBJECTIVE: To determine the biomechanical effects from the number of anterior rods (1 vs 2) and the effects of interbody structural support on construct stiffness after anterior multisegmental instrumentation. SUMMARY OF BACKGROUND DATA: Corrective surgery using anterior instrumentation for thoracolumbar and lumbar scoliosis has been performed with single rod and, more recently, with dual rod constructs. The biomechanical effect of one- or two-rod anterior instrumentation systems on construct stiffness and the addition or absence of interbody structural support have not been defined adequately in the literature. METHODS: Eight bovine lumbar spines each underwent instrumentation using four different constructs: one rod without interbody support; one rod with titanium mesh interbody support at the L2-L3, L3-L4, and L4-L5 disc spaces; two rods alone; and two rods with interbody support. Nondestructive cyclic testing in flexion-extension (+/-5 Nm), lateral bending (+/-5 Nm), and torsion (+/-2 Nm) were performed. The construct stiffness (Nm/ degrees ) of the four implant configurations was compared. RESULTS: With the addition of a second rod, the construct was significantly stiffer than a single rod construct in flexion (P = 0.006), extension (P = 0.02), and torsion (P = 0.01), but not in lateral bending. The addition of interbody structural support to the rod systems resulted in significantly stiffer constructs than those without cages in flexion (P = 0.03), but not in the other loading conditions (extension, lateral bending, torsion). CONCLUSIONS: Dual rod constructs were stiffer in torsion and flexion-extension loading than single rod constructs. Neither the number of rods nor the use of structural mesh interbody support had any effect on lateral bending stiffness. However, in a single rod system, the addition of interbody support increased stiffness in flexion. The use of structural support in dual rod constructs may be helpful in "setting" the desired lordosis, but adds little to construct stiffness.

Animals↗
PubMed1975

Combined hyertrophic subaortic stenosis and calcific aortic valvular stenosis.

A well documented case of combined hypertrophic subaortic stenosis and calcific aortic stenosis is reported. Detection of multilevel involvement in cases of left ventricular outflow obstruction requires a high index of suspicion and precise hemodynamic and angiographic documentation. Careful analysis of the total data base is necessary for proper management of the patient. The pathogenesis of this combined lesion is unclear: Asymmetrical septal hypertrophy may occur as a consequence of the valvular stenosis, or it may be that abnormal leaflet motion in patients with hypertrophic obstruction produces leaflet thickening, calcification, deformity and stenosis.

Aged↗
PubMed1999

Complications of buttress plate stabilization of cervical corpectomy.

STUDY DESIGN: A retrospective analysis of 14 patients treated with cervical corpectomy and buttress plate fixation. OBJECTIVES: To determine the complications of buttress plate fixation following multilevel cervical corpectomies. SUMMARY OF BACKGROUND DATA: Buttress plate fixation of multilevel cervical corpectomy has recently been reported. Biomechanical data suggests that it is preferable to long plates spanning the entire corpectomy site. There are no clinical studies that have specifically addressed the complications of this type of plate fixation. METHODS: The records and radiographs of all patients who had undergone cervical buttress plate fixation following anterior cervical corpectomy for myelopathy were independently reviewed. Twelve of the patients had three-level corpectomies and two had two-level corpectomies. All patients had placement of a short plate at the inferior end of the construct with sufficient overhang to act as a buttress against graft extrusion. Three patients underwent posterior cervical fusion in addition to the anterior procedure. RESULTS: Graft extrusion. One patient had complete graft extrusion on the third post-operative night. A second patient who had undergone circumferential fusion had minimal plate dislodgement secondary to graft settling. Pseudarthrosis. Three patients had pseudarthroses. Two of these required revision posterior surgery. Neurologic. None of the patients suffered neurologic complications. With the exception of the one patient who died, the rest of the patients all improved by at least one Nurick grade. CONCLUSION: The most catastrophic complication in the present series was plate dislodgement causing airway compromise and eventually resulting in death. Surgeons who utilize these types of buttress plates without additional posterior instrumentation should be aware of the potential complications of buttress plate fixation.

Adult↗
PubMed1999

Gait pattern in patients with spastic diplegic cerebral palsy who underwent staged operations.

Fifteen patients with spastic diplegic cerebral palsy (CP) were monitored for a mean length of 9.5 years after they underwent staged operations and were evaluated by gait analysis, including joint motion in the sagittal plane and the ground reaction force (GRF) in three dimensions. Results showed an increased hip flexion (132%) at midstance, a reduction of peak knee flexion (PKF) during swing (45%) accompanied by an augmented time of PKF during swing (50%), and an increased dorsiflexion of the ankle during swing (293%) as well as its time during the gait cycle, in comparison with normal values. Moreover, significant decreases of the vertical GRF at the terminal stance and the forward and backward GRF were present. Additionally, it was found that a bilateral popliteal angle < 20 degrees is acceptable in spastic CP. Staged operations gave unpredictable results in the correction of contracture of the hamstrings, the Achilles tendon, and the iliopsoas. The authors are convinced that gait analysis is useful in evaluating these patients and enhances the results of operative treatment, and they have since changed their approach toward multilevel simultaneous corrections.

Adolescent↗