Evolution of the curve patterns during brace treatment for adolescent idiopathic scoliosis

A Risk Quantification Reference Table for Progressed Adolescent Idiopathic Scoliosis Surgery: An Exact Case Matched Outcomes Analysis

STUDY DESIGN

Retrospective Exact Matched case-control study.

OBJECTIVES

Surgical treatment delay in AIS due to family preferences is common. This study aims to quantify the increase in risks as the Cobb angle increases and provide a Quantifiable Risk Reference Table that can be utilized for counseling.

METHODOLOGY

AIS patients were divided into 3 groups: Group A: Cobb angle 50-60°, Group 61-70°, and Group CFinal ≥80°. Each patient in Group CFinal who had curve progression were then traced-back-in-time (TBIT) to review the clinical data at earlier presentations at 50-60° (C1), and 61-70° (C2). Patient demographics, radiological, operative, and outcomes data were compared between Group A vs C1 and Group B vs Group C2.

RESULTS

A total of 614 AIS surgeries were reviewed. Utilizing the EM technique, a total of 302 AIS patients were recruited. There were 147, 111, 31, and 32 patients matched in Groups A, B, C1, and C2, respectively. C2 Final patients had 34% curve pattern change, 23.2% higher incidence of requiring two surgeries, and 17.3% increase in complications. There was a statistically significant increase of 2.4 spinal levels fused, 12% increase in implant density, 35% increase in operative time, 97% increase in intra-operative blood loss, 10% loss of scoliosis correction, 40% longer hospitalization stay, and 36% increase in costs for patients who had curve progression.

CONCLUSION

This study is the first to use a homogenously matched AIS cohort to provide a Quantifiable Risk Reference Table. The Risk Table provides essential knowledge for treating physicians when counseling AIS patients.

Does bracing for adolescent idiopathic scoliosis affect operative results?

STUDY DESIGN

Retrospective comparative study.

OBJECTIVES

We hypothesize that preoperative bracing for idiopathic scoliosis results in increased stiffness, as measured by reduced correction on bending films, ultimately leading to decreased surgical correction. Bracing is the primary nonoperative treatment for immature AIS patients with mild to moderate curves. For patients who fail bracing and proceed to operative intervention, it is unknown whether their nonoperative treatment impacts their surgical results.

METHODS

We conducted a single-center, retrospective, comparative study on 181 consecutive adolescent idiopathic scoliosis patients, aged 11-17 years, who underwent posterior spine fusion between 2011 and 2013. Patient flexibility was measured as percent change in the curve angle of the spine from standing to supine bend. Overall curve correction was calculated as the preoperative to postoperative change in standing coronal measure divided by the preoperative measurement and reported as a percentage.

RESULTS

One hundred and twelve subjects (62%) underwent bracing prior to fusion. Braced patients had similar preoperative major Cobb angles than unbraced patients (56.5 vs 59.0, p = 0.07). Preoperatively, braced patients achieved less primary curve correction in bending films (33.6%) than unbraced patients (40.6%, p = 0.003). Postoperatively, Cobb angle correction was not different between the braced (75.7%) and unbraced group (77.2%) overall (p = 0.41). There was no difference in blood loss (p = 0.14) or surgical time (p = 0.96) between braced and unbraced groups when adjusted for surgeon and number of levels fused.

CONCLUSIONS

While braced patients may demonstrate less preoperative flexibility, there is no evidence that braced patients experience decreased curve correction compared to unbraced patients. Bracing treatment did not impact operative results, as indicated by similar Cobb angle correction, estimated blood loss, and surgical time in both groups.

LEVEL OF EVIDENCE

III.

Does Curve Regression Occur During Underarm Bracing in Patients with Adolescent Idiopathic Scoliosis?

BACKGROUND

Successful brace treatment entails good control of scoliosis with avoidance of surgery. However, achieving curve regression may be an even better radiological result than prevention of curve progression for patients with adolescent idiopathic scoliosis. Vertebral remodeling may occur with well-fitted braces. Better in-brace curve correction may influence the likelihood of vertebral remodeling and the chance of curve regression. Only a few reports have evaluated curve regression with brace treatment, and the factors associated with these events are unknown.

QUESTIONS/PURPOSES

(1) What changes in curvature are observed with brace treatment for adolescent idiopathic scoliosis? (2) What factors are associated with curve improvement? (3) What factors are associated with curve deterioration? (4) Is curve regression associated with improvements in patient-reported objective outcome scores?

METHODS

Between September 2008 and December 2013, 666 patients with adolescent idiopathic scoliosis underwent underarm brace treatment and were followed until skeletal maturity at 18 years old. Among these patients, 80 were excluded because of early discontinuation of brace treatment (n = 66) and loss to follow-up (n = 14). Hence, 586 patients were included in this study, with a mean brace-wear duration of 3.8 ± 1.5 years and post-weaning follow-up duration of 2.0 ± 1.1 years. The mean age at baseline was 12.6 ± 1.2 years. Most patients were female (87%, 507 of 586) and up to 53% (267 of 507) of females were post-menarche. Bracing outcomes were based on changes in the Cobb angle measured out of brace. These included curve regression, as indicated by at least a 5° reduction in the Cobb angle, curve progression, as indicated by at least a 5° increase in the Cobb angle, and unchanged, as indicated by a change in the Cobb angle of less than 5°. We studied the pre-brace and supine Cobb angles, curve flexibility (pre-brace Cobb angle - supine Cobb angle / pre-brace Cobb angle x 100%), correction rate (pre-brace Cobb angle - in-brace Cobb angle / pre-brace Cobb angle x 100%), location of apical vertebrae, apical ratio (convex vertebral height/concave vertebral height), change in the major curve Cobb angle, and apical ratio post-bracing. The refined 22-item Scoliosis Research Society questionnaire was used for patient-reported outcomes and is composed of five domains (function, pain, appearance, mental health and satisfaction with treatment). Its minimum clinically important difference, based on a scale from 0 to 5, has been quoted as 0.2 for pain, 0.08 for activity and 0.98 for appearance domains. Mental health has no quoted minimum clinically important difference for the adolescent idiopathic scoliosis population. Satisfaction with treatment is described based on improvement or deterioration in domain scores. Intergroup differences between bracing outcomes were evaluated with the Kruskal Wallis test. Univariate analyses of bracing outcomes were performed with a point-biserial correlation coefficient for continuous variables and Pearson's chi-square test for categorical variables. Multivariate logistic regression models were created for improved and deteriorated outcomes. P values < 0.05 were considered significant.

RESULTS

In all, 17% of patients (98 of 586) had an improved angle and 40% of patients (234 of 586) had curve deterioration. In patients who improved, the mean reduction in the Cobb angle was 9 ± 4°, while in patients who deteriorated, the mean increase in the Cobb angle was 15 ± 9°, and this was maintained at the latest post-brace weaning follow-up. Despite a trend for patients with curve regression to have higher baseline flexibility and correction rate, after controlling for age, Risser staging, radius and ulnar grading, and Sanders staging, we found no clinically important differences with increased correction rate or flexibility. We did find that improvement in the Cobb angle after bracing was associated with reduced apical ratio (odds ratio [OR] 0.84 [95% CI 0.80 to 0.87]; p < 0.001). Curve progression was associated with younger age (OR 0.71 [95% CI 0.55 to 0.91]; p = 0.008), pre-menarche status (OR 2.46 [95% CI 1.31 to 4.62]; p = 0.005), and increased apical ratio (OR 1.24 [95% CI 1.19 to 1.30]; p < 0.001) but no clinically important differences were observed with less flexible curves and reduced correction rate. Improvements in scores of the refined 22-item Scoliosis Research Society domains of function (mean difference on a scale from 0 to 5: 0.2; p = 0.001 versus 0.1; p < 0.001) and pain (mean difference on a scale from 0 to 5: 0.2; p = 0.020 versus 0.0; p = 0.853) were greater in the post-brace improvement group than in the deterioration group and fulfilled the minimum clinically important difference threshold. The appearance domain did not fulfill the minimum clinically important difference. Satisfaction with treatment domain score minimally improved with the curve regression group (mean difference on a scale from 0 to 5: 0.2) but deteriorated in the curve progression group (mean difference on a scale from 0 to 5: -0.4).

CONCLUSIONS

Curve regression occurs after underarm bracing and is associated with superior patient-reported outcome scores. This possible change in Cobb angle should be explained to patients before and during bracing. Whether this may help improve patients' duration of brace-wear should be addressed in future studies. Patients with well-fitting braces may experience curve improvement and possible vertebral remodeling. Those braced at a younger age and with increased vertebral wedging are more likely to have curve progression.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Supine flexibility predicts curve progression for patients with adolescent idiopathic scoliosis undergoing underarm bracing

Aims

The aim of this study was to assess whether supine flexibility predicts the likelihood of curve progression in patients with adolescent idiopathic scoliosis (AIS) undergoing brace treatment.

Methods

This was a retrospective analysis of patients with AIS prescribed with an underarm brace between September 2008 to April 2013 and followed up until 18 years of age or required surgery. Patients with structural proximal curves that preclude underarm bracing, those who were lost to follow-up, and those who had poor compliance to bracing (<16 hours a day) were excluded. The major curve Cobb angle, curve type, and location were measured on the pre-brace standing posteroanterior (PA) radiograph, supine whole spine radiograph, initial in-brace standing PA radiograph, and the post-brace weaning standing PA radiograph. Validation of the previous in-brace Cobb angle regression model was performed. The outcome of curve progression post-bracing was tested using a logistic regression model. The supine flexibility cut-off for curve progression was analyzed with receiver operating characteristic curve.

Results

A total of 586 patients with mean age of 12.6 years (SD 1.2) remained for analysis after exclusion. The baseline Cobb angle was similar for thoracic major curves (31.6° (SD 3.8°)) and lumbar major curves (30.3° (SD 3.7°)). Curve progression was more common in the thoracic curves than lumbar curves with mean final Cobb angles of 40.5° (SD 12.5°) and 31.8° (SD 9.8°) respectively. This dataset matched the prediction model for in-brace Cobb angle with less mean absolute error in thoracic curves (0.61) as compared to lumbar curves (1.04). Reduced age and Risser stage, thoracic curves, increased pre-brace Cobb angle, and reduced correction and flexibility rates predicted increased likelihood of curve progression. Flexibility rate of more than 28% has likelihood of preventing curve progression with bracing.

Conclusion

Supine radiographs provide satisfactory prediction for in-brace correction and post-bracing curve magnitude. The flexibility of the curve is a guide to determine the likelihood for brace success. Cite this article: Bone Joint J 2020;102-B(2):254–260.

Brace Treatment in Adolescent Idiopathic Scoliosis Patients with Curve Between 40° and 45°: Effectiveness and Related Factors

OBJECTIVE

To investigate effectiveness of brace treatment in patients with adolescent idiopathic scoliosis with curve between 40° and 45° and to determine predictive factors associated with bracing outcome.

METHODS

Bracing was used to treat 90 patients with curve >40 degrees. Factors including Risser sign, age, sex, curve pattern, curve magnitude, and initial curve correction were compared between patients with curve improvement and patients with curve progression. Logistic regression analysis was used to determine the independent predictors of curve progression.

RESULTS

Curve was improved in 34 (37.8%) patients and stabilized in 12 (13.3%) patients. Remarkable curve progression >50 degrees was observed in 44 (48.9%) patients. Intergroup comparison showed significant differences between the 2 groups in terms of age (12.3 ± 1.4 years vs. 13.2 ± 1.6 years, P = 0.01), initial curve correction (2.2% ± 5.4% vs. 19.7% ± 12.2%, P < 0.001), and curve pattern (P = 0.03). Logistic regression analysis showed that initial curve correction of <10% (odds ratio = 12.82, P < 0.001) and Risser grade of 0 (odds ratio = 1.46, P = 0.04) were significant indicators of curve progression.

CONCLUSIONS

Bracing may produce a favorable outcome in certain patients with curve between 40° and 45°. It should be cautiously used in this situation, as there was a higher probability of bracing failure. It is important to differentiate patients at high risk of curve progression at an early stage to avoid overtreatment.

Effect of Group Exercising and Adjusting the Brace at Shorter Intervals on Cobb Angle and Quality of Life of Patients With Idiopathic Scoliosis

OBJECTIVE

The aim of the study was to evaluate the effect of group exercise with brace adjustment at shorter intervals than used in routine practice in late-onset idiopathic scoliosis patients.

DESIGN

This was a quasi-experimental study. Thirty patients with progressive scoliosis curves of 15-50 degrees and a prescription for a brace were divided into experimental and control groups, both of which participated in an 11-wk treatment program. Those in the experimental group underwent brace adjustment twice per week and performed group exercise, whereas those in the control group received a routine protocol. The quality of life and Cobb angle of patients in both groups were evaluated based on baseline and final results of the 22-item Scoliosis Research Society questionnaire and primary and secondary radiographs.

RESULTS

In the experimental group, the improvement in Cobb angle and patient satisfaction was greater than that in the control group (P < 0.05). Moreover, in patients with Cobb angles of less than 30 degrees, the self-image and satisfaction domains and the total scores of patients in the experimental group were significantly different from those in the control group at the final assessment (P < 0.05).

CONCLUSIONS

Brace adjustment at shorter intervals combined with group exercise increases patient satisfaction and reduces scoliosis Cobb angles.

Reproducibility of sagittal radiographic parameters in adolescent idiopathic scoliosis-a guide to reference values using serial imaging

BACKGROUND CONTEXT

Knowledge of sagittal radiographic parameters in adolescent idiopathic scoliosis (AIS) patients has not yet caught up with our understanding of their roles in patients with adult spinal deformity. It is likely that more emphasis will be placed in restoring sagittal parameters for AIS patients in the future. Therefore, we need to understand how these parameters may vary in AIS to facilitate management plans.

PURPOSE

This study aimed to determine the reproducibility of sagittal spinal parameters on lateral film radiographs in patients with AIS.

STUDY DESIGN/SETTING

This was a retrospective, comparative study conducted in a tertiary health-care institution from January 2013 to February 2016 (3-year period).

PATIENT SAMPLE

All AIS patients who underwent deformity correction surgery from January 2013 to February 2016 and had two preoperative serial lateral radiographs taken within the time period of a month were included in the study.

OUTCOME MEASURES

Radiographic sagittal spinal parameters including sagittal vertical axis (SVA), cervical lordosis (CL), thoracic kyphosis (TK), thoracolumbar alignment (TL), lumbar lordosis (LL); standard spinopelvic measurements such as pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS); as well as end and apical vertebrae of cervical, thoracic, and lumbar curves were the outcome measures.

METHODS

All patient data were pooled from electronic medical records, and X-ray images were retrieved from Centricity Enterprise Web. Averaged X-ray measurements by two independent assessors were analyzed by comparing two radiographs of the same patients performed within a 1-month time period. Chi-squared and Wilcoxon signed-rank tests were used for categorical and continuous variables.

RESULTS

The study cohort comprised 138 patients, 28 men and 110 women, with a mean age of 15 years (range 11-20). Between the two lateral X-rays, there was a mean difference of 0.79 cm in SVA (p<.001), 0.70° in LL (p=.033), and 0.73° in PT (p=.010). In the combined Lenke 1 and 2 subgroup, there was a similar 0.77 cm (p=.002), 0.79° (p=.009), and 1.49° (p=.001) mean difference in SVA, LL, and PT, respectively. Additionally, there was also a 1.85° (p=.009) and 1.76° (p=.006) mean difference seen in TL and SS, respectively. The overall profile of the sagittal curves remained largely similar, with only the lumbar apex shifting from L3 to L4 during the first and the second X-rays, respectively (p<.001). This occurred for the combined Lenke 1 and 2 subgroup as well (p<.001).

CONCLUSION

Most radiographic sagittal spinal parameters in AIS patients are generally reproducible with some variations up to a maximum of 4°. This natural variation should be taken into account when interpreting these radiographic sagittal parameters so as to achieve the most accurate results in surgical planning.

Evaluation of the influences of various force magnitudes and configurations on scoliotic curve correction using finite element analysis

Scoliosis is a lateral curvature in the normally straight vertical line of the spine, and the curvature can be moderate to severe. Different treatment can be used based on severity and age of subjects, but most common treatment for this disease is using orthosis. To design orthosis types of force arrangement can be varied, from transverse loads to vertical loads or combination of them. But it is not well introduced how orthoses control scoliotic curve and how to achieve the maximum correction based on force configurations and magnitude. Therefore, it was aimed to determine the effect of various loads configurations and magnitudes on curve correction of a degenerative scoliotic subject. A scoliotic subject participated in this study. The CT-Scan of the subject was used to produce 3D model of spine. The 3D model of spine was produced by Mimics software and the finite element analysis and deformation of scoliotic curve of the spine under seven different forces and in three different conditions was determined by ABAQUS software. The Cobb angle in scoliosis curve decreased significantly by applying forces. In each condition depends on different forces, different corrections have been achieved. It can be concluded that the configurations of the force application mentioned in this study is effective to decrease the scoliosis curve. Although it is a case study, it can be used for a vast number of subjects to predict the correction of scoliosis curve before orthotic treatment. Moreover, it is recommended that this method and the outputs can be compared with clinical findings.

Lyon bracing in adolescent females with thoracic idiopathic scoliosis: a prospective study based on SRS and SOSORT criteria

Background

The Lyon brace is commonly prescribed in many European countries to patients with thoracic curves and is based on the three-point pressure system.

The purpose of this study was to evaluate the efficacy of Lyon bracing for the conservative treatment of adolescent females with idiopathic thoracic curves in a case series selected on the basis of the Scoliosis Research Society (SRS) Committee on Bracing and Nonoperative Management Standardization Criteria and followed the guidelines on management of idiopathic scoliosis with corrective braces, proposed by the International Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT).

Methods

Prospective study based on an ongoing database.

From 1297 patients treated for idiopathic scoliosis between 1995 and 2014 fulfill the inclusion criteria 102 patients treated with Lyon brace. Of these, 69 patients had a definite outcome, 17 have abandoned treatment e 16 are still in treatment. The 104 patients were adolescent females with curvatures in the thoracic spine and a pre-treatment Risser score ranging from 0 to 2. All patients were prescribed with full-time Lyon bracing. The minimum duration of follow-up was 24 months after the end of weaning (mean: 41.64 ± 31.45 months). Anteroposterior radiographs were used to estimate the curve magnitude (C_M) at 5 time points: beginning of treatment (t1), one year after the beginning of treatment (t2), intermediate time between t1 and t4 (t3), end of weaning (t4), 2-year minimum follow-up from t4 (t5). Three outcomes were distinguished: curve correction, curve stabilization and curve progression.

Results

The results from our study showed that of the 69 patients with a definite outcome the C_M mean value was 31.51° ± 4.34 SD at t1 and 20° ± 7.6 SD at t5. Curve correction was accomplished in 85.5 % of patients, curve stabilization was obtained in 13 % of patients and curve progression was evident in only 1.5 %. None of the patients were recommended surgery post-bracing. Of 17 patients who abandoned the treatment, at the time of abandonment (14.4 age) have achieved curve correction in 13 cases (77 %), stabilization in 53 cases (18 %) and progression in 1 case (5 %).

Conclusion

The Lyon brace, through its biomechanical action on vertebral modeling, is highly effective in correcting thoracic curves in particularly when the SOSORT guidelines were adopted in addition to the SRS criteria.

Effect of a spinal brace on postural control in different sensory conditions in adolescent idiopathic scoliosis: a preliminary analysis

BACKGROUND

Despite the positive effects of spinal braces on postural stability, they may constrain movement, resulting in poor balance control in patients with adolescent idiopathic scoliosis (AIS). Therefore, assessment of postural dynamics may aid in designing new less-constraining braces.

OBJECTIVES

The effects of a spinal brace on postural stability and Cobb angle were investigated in this study.

METHODS

Thirteen pediatric patients (10 females, three males) with AIS were recruited to participate in the study. Cobb angle was assessed by X-ray analyses, and postural stability was tested by computerized dynamic posturography in braced and unbraced conditions. A polyethylene underarm corrective spinal brace was fabricated for the subjects.

RESULTS

Thoracic and lumbar curvature decreased to 18.88 ± 11.73° and 17.70 ± 10.58°, respectively, after bracing (p < 0.05). Lower equilibrium scores were observed in the "eyes closed" condition and higher scores in the "eyes closed with a swaying support" condition; higher composite equilibrium scores were also observed for the sensory organization test (p < 0.05) in the braced condition. Lower scores were observed for the "toes-up adaptation test" in the braced condition (p < 0.05). In the braced condition, the reaction time was slower in the right-backward direction and movement velocity was higher in the right-front direction on the limits of stability test (p < 0.05). Furthermore, lower on-axis velocity during forward/backward dynamic balance control was observed in the braced condition (p < 0.05).

CONCLUSIONS

Wearing a spinal brace improved postural stability in terms of increased proprioception, equilibrium performance, and rhythmic movement ability in patients with AIS.

Does delaying surgery in immature adolescent idiopathic scoliosis patients with progressive curve, lead to addition of fusion levels?

PURPOSE

To analyze the changes in the curve extent, pattern and the fusion level in adolescent idiopathic scoliosis (AIS) patients who undergo delayed surgery instead of early surgery.

METHODS

Thirty-five immature AIS patients whose radiographs demonstrated an initial primary curve of more than 40° with a subsequent increase of 10° before attaining skeletal maturity with brace were enrolled. The initial and the final radiographs taken before surgery were compared to assess the changes in curve extent, pattern and the fusion levels as recommended by King's, Lenke's and Suk's guidelines.

RESULTS

The average age of 35 AIS patients was 12.7 ± 1.6 years. The time interval between initial and final radiography was 39.3 ± 20.2 months and the degree of progress of the primary curve was 13 ± 9.7°. Fusion levels changed in 33 (94.2%), 33 (94.2%) and 32 (91.4%) patients according to King's, Lenke's and Suk's guidelines, respectively. Curve pattern was changed in 2 (5.7%), 12 (34.3%) and 10 (28.6) patients by King's, Lenke's and Suk's guidelines. The mean number of levels requiring fusion increased from 9.4 ± 2.1 at initial visit to 11.1 ± 1.8 at the final follow-up using King's guidelines, 9.7 ± 2.2-11.6 ± 2.0 as per Lenke's guidelines and 9.1 ± 2.0-11.5 ± 2.3 when fusion was planned using Suk's guidelines (p < 0.001 in all guidelines).

CONCLUSIONS

Delay of surgery in immature AIS patients whose Cobb's angle exceed 40° initially and showing subsequent progression of the curve, of more than 10° can lead to alterations in the curve pattern and the need for increase in fusion levels.

Very short-term effect of brace wearing on gait in adolescent idiopathic scoliosis girls

PURPOSE

Adolescent idiopathic scoliotic (AIS) deformity induces excessive oxygen consumption correlated to a bilateral increase of lumbo-pelvic muscles timing activity (EMG) during gait. Wearing a brace, the usual treatment for AIS, by supporting the spine and the pelvis, would generate lumbo-pelvic muscular relaxation and consequently reduce excessive oxygen consumption. The purpose of this study was to evaluate the short-term effect of bracing on gait biomechanics in scoliotic spine when compared with normal braced spine.

METHODS

Thirteen healthy volunteers were compared to 13 AIS girls. In both samples, gait analysis was assessed using a three-dimensional motion analysis, including synchronous kinematic, electromyographic, mechanical and energy measurements, first without brace, then wearing a brace.

RESULTS

For scoliotic patients, comparison of in-brace and out-brace situations revealed a significant decrease of frontal pelvis (p < 0.001), hip (p < 0.001) and shoulder (p = 0.004) motion in brace associated with a significant reduction of pelvis rotation (p = 0.003). However, the brace did not change significantly the lumbo-pelvic muscle activity duration (EMG) or the mechanical and energetic parameters. Transversal pelvis motion was reduced by 39% (p = 0.04), frontal hip and shoulder motions by 23% (p = 0.004) and 30% (p = 0.01) respectively, and energy cost of walking remained increased by 37% in braced AIS girls relatively to braced healthy subjects. Mechanical and electromyographic variables were not significantly different between the two braced populations during gait except for the gluteus medius muscle that showed bilaterally an increase of duration of electrical activity in healthy subjects and contrarily a decrease in AIS patients (healthy: -3.5 ± 9.6% of gait cycle vs. scoliotic: 3.7 ± 7.7% of gait cycle; p = 0.04).

CONCLUSIONS

Bracing changed neither the oxygen consumption nor the timing of the lumbo-pelvic muscles activity in both groups during gait. However, in brace the timing activity of bilateral gluteus medius muscles tended to decrease in AIS patients and increase in healthy subjects. Moreover, braced AIS patients had more restricted frontal hips and shoulder motion as well as pelvis rotation than braced healthy subjects.

Does brace treatment impact upon the flexibility and the correctability of idiopathic scoliosis in adolescents?

PURPOSE

Brace treatment has served as a vital non-surgical procedure for immature adolescent idiopathic scoliosis (AIS) patients with a mild or moderate curve. For the patients who fail in bracing and resort to surgery, it is unclear whether prior full-time brace treatment significantly influences outcomes. This study aims to investigate whether prior brace treatment has a negative impact upon the flexibility and correctability of the main curve in patients with AIS.

METHODS

The participants were collected from female AIS patients who underwent posterior correction surgery with pedicle screw instrumentation from August 2006 to December 2010, with or without prior brace treatment. Patients included in Group A had prior brace treatment over a 1-year period, and underwent surgery within 6 months after cessation of bracing; those in Group B received no prior treatment and were randomly selected from our database. Curve flexibility pre-surgery and curve correctability post-surgery were computed and compared between both groups and subgroups according to the curve location.

RESULTS

Each group consisted of 35 patients. Age, curve magnitude and location were comparable between the two groups. Before surgery, patients in Group A had a slightly lower curve flexibility than those in Group B (52 vs. 60 %, P = 0.036). After surgery, satisfactory correction results were observed in both groups, but the average post-operative main curve magnitude of patients in Group B was 4° less than that of Group A (10° vs. 14°, P = 0.010). The curve correctability in Group B was significantly higher than that in Group A (80 vs. 74 %, P = 0.002). No matter what curve pattern the patient had, having a prior history of brace treatment resulted in a trend of lower flexibility and correctability of their scoliosis.

CONCLUSIONS

Good surgical correction can be achieved in AIS patients who have been unsuccessful with prior brace treatment. However, a history of prior brace treatment leads to a trend of lowering the curve flexibility, and in turn, negatively impacts upon the curve correctability.