Doug Hill

Trunk distortion in adolescent idiopathic scoliosis.

Trunk images of children with scoliosis were examined to determine features that contribute to the impression of trunk distortion. Twenty subjects with spinal deformity ranging from none to severe were photographed in a relaxed standing position. Seven blinded evaluators subjectively scored their impressions of the trunk appearance, shoulder-height difference, shoulder-angle asymmetry, decompensation, scapula asymmetry, waist crease, waist asymmetry, and pelvic asymmetry. Regression analysis was used with the latter seven features to predict overall impression. The seven measures of the deformity predicted 85% of the overall impression of trunk distortion; scapular asymmetry was the best predictor. Trunk deformity is the most obvious effect of scoliosis to the patients. Objective approaches to the assessment of this important but difficult-to-quantify aspect of idiopathic scoliosis are available and should be used to evaluate treatment outcomes.

A support vector machines classifier to assess the severity of idiopathic scoliosis from surface topography

A support vector machines (SVM) classifier was used to assess the severity of idiopathic scoliosis (IS) based on surface topographic images of human backs. Scoliosis is a condition that involves abnormal lateral curvature and rotation of the spine that usually causes noticeable trunk deformities. Based on the hypothesis that combining surface topography and clinical data using a SVM would produce better assessment results, we conducted a study using a dataset of 111 IS patients. Twelve surface and clinical indicators were obtained for each patient. The result of testing on the dataset showed that the system achieved 69-85% accuracy in testing. It outperformed a linear discriminant function classifier and a decision tree classifier on the dataset

A Comparison of Four Computerized Methods for Measuring Vertebral Rotation

The ability to measure vertebral rotation is particularly important in the assessment and treatment of scoliosis. We determined the accuracy and precision of four methods that may be used with routine anteroposterior (AP) spine radiographs. Two vertebrae were radiographed at 0° and at 5° intervals to 20° and at 30°, to the right and left. The radiographs were distributed to three members of the staff who marked the 14 points required for calculating rotation with the four methods. The points were digitized, and rotation calculated by computer. The results showed no significant difference in the calculated rotation of the two vertebrae, or between the results of the three markers. Stokess method was significantly the least accurate. The other three methods were not significantly different but Bunnells method appeared to give more consistent results.

Discriminative and predictive validity of the scoliosis research society-22 questionnaire in management and curve-severity subgroups of adolescents with idiopathic scoliosis.

Study Design. Prospective cross-sectional measurement study. Objective. To determine the ability of the Scoliosis Research Society (SRS)-22 questionnaire to discriminate among management and scoliosis severity subgroups and to correlate with internal and external measures of curve severity. Summary of Background Data. In earlier studies of the SRS-22 discriminative ability, age was not a controlled factor. The ability of the SRS-22 to predict curve severity has not been thoroughly examined. Methods. The SRS-22 was completed by 227 females with adolescent idiopathic scoliosis. Using Analysis of covariance analyses controlling for age, the SRS-22 scores were compared among management subgroups (observation, brace, presurgery, and postsurgery) and curve-severity subgroups (in nonoperated subjects: Cobb angles of <30°, 30°–50°, and >50°). A stepwise discriminant analysis was used to identify the SRS-22 domains most discriminative for curve-severity categories. Correlation between SRS-22 scores and radiographic or surface topography measurements was used to determine the predictive ability of the questionnaire. Results. Pain was better for subjects treated with braces than for those planning surgery. Self-image was better for subjects under observation or postsurgery than for those planning surgery. Satisfaction was better for the brace and postsurgery subgroups than for the observation or presurgery subgroups. Statistically significant mean differences between subgroups were all larger than 0.5, which is within the range of minimal clinically important differences recommended for each of the 5-point SRS-22 domain scoring scales. Pain and mental health were worse for those with Cobb angles of >50° than with Cobb angles of 30° to 50°. Self-image and total scores were worse for those with Cobb angles of >50° than both other subgroups. Using discriminant analysis, self-image was the only SRS-22 domain score selected to classify subjects within curve severity subgroups. The percentage of patients accurately classified was 54% when trying to classify within 3 curve severity subgroups. The percentage of patients accurately classified was 73% when classifying simply as those with curves larger or smaller than 50°. Conclusion. Pain, self-image, and satisfaction scores could discriminate among management subgroups, but function, mental health and total scores could not. The total score and all domain scores except satisfaction discriminated among curve-severity subgroups. Using discriminant analysis, self-image was the only domain retained in a model predicting curve-severity categories.

Score distribution of the scoliosis research society-22 questionnaire in subgroups of patients of all ages with idiopathic scoliosis.

Study Design. Cross-sectional measurement study. Objective. To analyze the score distribution of the Scoliosis Research Society (SRS)-22 questionnaire domains and items for patients with idiopathic scoliosis (IS) of all ages. Summary of Background Data. Scoliosis-related quality-of-life questionnaires have demonstrated high ceiling effects in younger patients. However, the score distribution has not been examined thoroughly in other clinically relevant IS subgroups. Methods. The SRS-22 was completed by 173 females with IS. The proportions of ceiling effects, floor effects, of patients scoring greater than or equal to 4 out of 5 and the box plots of the score distribution for each domain and item were compared between subgroups. Subgroups were formed based on age (k = 4), management (k = 6), curve severity (k = 3), and curve type (k = 4). Results. Domain ceiling effects varied between 0% and 23.1%. Domain floor effects were observed only for Self-image (<7%) and Satisfaction (<12%). Only Pain and Satisfaction showed moderate (>20%) ceiling effects. Ceiling effects for Pain and Mental Health decreased with increasing age (P < 0.05). Pain ceiling effects decreased and Satisfaction ceiling effects increased from least to most invasive management (P < 0.05), but no differences were found among Cobb severity or curve types subgroups. Of the 22 items, 9 had major (≥50%) ceiling effects and 11 had moderate ceiling effects. Most subgroups (14/16) had 4 to 6 items with major ceiling effects. The following items had major ceiling effects in the majority of subgroups: Function, 9 and 15; Pain, 11 and 17; and Self-image, 14. Conclusion. Most SRS-22 domains had acceptable levels of ceiling effects (<20%) in the majority of the subgroups examined. However, more sensitive measurements may be needed to supplement the SRS-22 in assessing Pain in patients below 18 years or Satisfaction after surgery.

Correlation between quantity and quality of orthosis wear and treatment outcomes in adolescent idiopathic scoliosis.

Orthotic treatment is the most commonly used non-surgical treatment method for adolescent idiopathic scoliosis (AIS). This study determined whether treatment outcome correlates with how often and how well children with AIS wear their orthoses. Eighteen (18) subjects (3M, 15F) who were diagnosed with idiopathic scoliosis and had wom their orthoses from 6 months up to 1 year participated in this study. All subjects were prescribed Boston braces to be wom full time (23hrs/day). Twelve (12) subjects who completed their brace treatment were included in the data analysis. Three (3) treatment outcomes were classified as improvement, no change and deterioration. The quality of the brace wear was assessed by how often the brace was wom with zero force, below 80%, between 80 to 120%, and above 120% of the load level prescribed in the clinic. The quantity of brace wear was determined by how many hours per day they wore their brace. Subjects who wear their braces tighter and for more hours per day seem to have better outcomes.

Thoracic Lordosis in Idiopathic Scoliosis

Lordosis, a significant aspect of thoracic scoliosis, is difficult to assess with routine clinical radiographs. Computerized analysis of 138 sets of standardized anteroposterior and lateral radiographs served to elicit the three-dimensional structure of scoliosis. Spinal curvatures in the usual anatomic planes and in the sagittal and frontal planes of the apical vertebrae were measured. Lordosis was present in 35% of curves greater than or equal to 40 degrees and in 50% of curves greater than 49 degrees. Lordosis may be a contraindication for brace treatment.

The Association Between Scoliosis Research Society-22 Scores and Scoliosis Severity Changes at a Clinically Relevant Threshold

Study Design. Cross-sectional correlation study. Objective. To determine the threshold in spinal deformity severity measurements beyond which there is a progressive decline in health-related quality-of-life (HRQOL). Summary of Background Data. The associations between HRQOL and scoliosis deformity measures are at best moderate when assessed using linear regressions. This may be because HRQOL is not affected until a severity threshold is reached. Identifying the thresholds in deformity beyond which HRQOL deteriorates could assist in treatment recommendations. Methods. The Scoliosis Research Society-22 (SRS-22) questionnaire was completed by 101 females with adolescent idiopathic scoliosis (age, 15.0 ± 1.8; largest Cobb angle, 36.9° ± 14.6°). Radiographs and surface topography were used to quantify the severity of the internal (largest Cobb angle) and external deformity (cosmetic score, decompensation, trunk twist), respectively. Segmented linear regression models were estimated to determine the association between SRS-22 domains and spinal deformity measures. This analysis also identifies deformity thresholds beyond which HRQOL is more affected. The percentage of variance explained (R2) by linear and segmented models were compared (α = 0.05) to identify the best models. Results. Cobb angle predicted significantly more variance in all SRS-22 domains except mental health using segmented models (R2: 0.09–0.30) than linear models (R2: 0.02–0.21). Segmented models with a single threshold estimated at a Cobb angle between 43° and 48° predicted between 3% and 11% more variance compared to corresponding linear model using the same variables. Surface topography parameters were not strongly associated with SRS-22 variables with linear and segmented models explaining less than 10% of the variance. Conclusion. Deterioration in SRS-22 scores is mildly associated with increases in the severity of the internal deformity. HRQOL is stable until the curve reaches a maximal Cobb angle threshold at ≈45° where HRQOL declines linearly with increasing internal deformity. The association between HRQOL and scoliosis severity is low, but is better explained by segmented rather than linear models.

The daily force pattern of spinal orthoses in subjects with adolescent idiopathic scoliosis

The efficacy of orthotic treatment for children with abnormal spinal curvature has been hampered by the lack of comprehensive information about wear characteristics. A battery-powered microcomputer system was developed to monitor loads exerted by orthoses used to treat children with spinal deformities during daily living. The system not only records how well the orthosis has been used, but also helps to ensure that the orthosis is being worn as prescribed. Data acquisition is controlled by a microcontroller and can be programmed to have sample intervals ranging from 1 second to 1 hour. Low power control circuitry is designed so that the system can be operated by a battery. In a preliminary study, 16 subjects (3M, 13F) used this system from 1 to 16 days (9.3±5.0) with the prescribed hours between 16 to 23 hours (22.3±1.3). This study demonstrated the feasibility of the approach, and that this device may increase the understanding of orthotic mechanics, and may help patients to wear their orthoses in a better way.

An objective measurement of brace usage for the treatment of adolescent idiopathic scoliosis.

Effectiveness of orthotic treatment for scoliosis depends on how much time and how well the orthosis is worn. Questionnaires and clinical judgment are subjective methods to wear compliance. Even though using a temperature sensor can objectively record how long the orthosis has been used, it may not be able to answer the orthosis effectiveness without knowing the wear tightness. Custom made thoracolumbosacral orthoses (TLSO) were instrumented with low power wireless data acquisition systems to measure the time and loads imposed by the pressure pad during daily activities. Force measurements were recorded at 1 sample/min and the system was able to record data up to 4 months without patient-involvement. Ten subjects (9F, 1M), age between 9 and 13.5 years, average 11.6±1.3 years, who prescribed a new TLSO and full-time brace wear were took part in this study over 4.4±1.0 months. Long-term logging of loads within a spinal orthosis is a reliable method to measure compliance objectively. The monthly quantity of brace wear ranged from 33% to 82%, average 60.0±4.3%. The monthly average loads imposed by the pressure pads varied from 39% to 78% relative to the reference level, average 64.3±4.6%. There was a statistically significant decrease in force, but increase in wear time over the period after the brace fitting session. This information may help to better understand the effectiveness of bracing and to predict the brace treatment outcomes.