Radiologic findings and curve progression 22 years after treatment for adolescent idiopathic scoliosis: comparison of brace and surgical treatment with matching control group of straight individuals

STUDY DESIGN: This study is a follow-up investigation for a consecutive series of patients with adolescent idiopathic scoliosis treated between 1968 and 1977. In this series, 156 patients underwent surgery with distraction and fusion using Harrington rods, and 127 were treated with brace. OBJECTIVES: To determine the long-term outcome in terms of radiologic findings and curve progression at least 20 years after completion of the treatment. SUMMARY OF BACKGROUND DATA: Radiologic appearance is important in comparing the outcome of different treatment options and in evaluating clinical results. Earlier studies have shown a slight increase of the Cobb angle in brace-treated patients with time, but not in fused patients. METHODS: Of 283 patients, 252 attended a clinical and radiologic follow-up assessment by an unbiased observer (91% of the surgically treated and 87% of the brace-treated patients). This evaluation included chart reviews, validated questionnaires, clinical examination, and full-length standing frontal and lateral roentgenographs. Curve size was measured by the Cobb method on anteroposterior roentgenograms as well as by sagittal contour and balance on lateral films. The occurrence of any degenerative changes or other complications was noted. An age- and gender-matched control group of 100 individuals was randomly selected and subjected to the same examinations. RESULTS: The mean follow-up times were 23 years for surgically treated group and 22 years for brace-treated group. The deterioration of the curves was 3.5 degrees for all the surgically treated curves and 7.9 degrees for all the brace-treated curves (P < 0.001). Five patients, all brace-treated, had a curve increase of 20 degrees or more. The overall complication rate after surgery was low: Pseudarthrosis occurred in three patients, and flat back syndrome developed in four patients. Eight of the patients treated with fusion (5.1%) had undergone some additional curve-related surgical procedure. The lumbar lordosis was less in the surgically treated than in the brace-treated patients or the control group (mean, 33 degrees vs 45 degrees and 44 degrees, respectively). Both surgically treated and brace-treated patients had more degenerative disc changes than the control participants (P < 0.001), but no significant differences were found between the scoliosis groups. No statistically significant difference in terms of radiographically detectable degenerative changes in the unfused lumbar discs was found between patients fused below L3 or those fused to L3 and above (P = 0.22). A study on intra- and interobserver measurements of kyphosis, lordosis, and sagittal vertical axis on two films for each patient demonstrated that the repeatability of measuring sagittal plumbline on two different lateral radiographs, with patients moving between radiograms, was unreliable for comparison. CONCLUSIONS: Although more than 20 years had passed since completion of the treatment, most of the curves did not increase. The surgical complication rate was low. Degenerative disc changes were more common in both patient groups than in the control group.     

青少年特发性脊柱侧凸生长潜能及侧凸进展风险评估的研究进展

<正>青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)是一种发生于青春发育高峰期的、以女性多见的脊柱畸形,不同国家与地区的AIS发病率波动在1%~4%[1、2]。支具治疗被证明是唯一有效的非手术治疗AIS的策略[3~6],但在严格的支具治疗下,仍有部分患儿最终会因侧凸进展而必须行手术治疗[7、8]。因此,在临床治疗中如能准确评估AIS患儿的侧凸进展风险,则可以根据不同的侧凸进展风险制定不同的治疗策略,从而改善AIS患儿的预     

Osteopenia: a new prognostic factor of curve progression in adolescent idiopathic scoliosis

BACKGROUND: Studies have shown that 27% to 38% of girls with adolescent idiopathic scoliosis have systemic osteopenia. The aim of this study was to investigate whether osteopenia could serve as one of the important prognostic factors in predicting curve progression. METHODS: A prospective study was performed in 324 adolescent girls with adolescent idiopathic scoliosis who had a mean age of thirteen and a half years. Bone mineral density of the spine and both hips was measured at the time of the clinical diagnosis of scoliosis. All patients were followed longitudinally until skeletal maturity or until the curve had progressed > or =6 degrees . The univariate chi-square test and stepwise logistic regression were used to predict the prevalence of curve progression, and a receiver operating characteristic curve was plotted. RESULTS: The overall prevalence of curve progression was 50%. The prevalence of osteopenia at the spine and hips was 27.5% and 23.1%, respectively. A larger initial Cobb angle (odds ratio = 4.6), a lower Risser grade (odds ratio = 4.7), premenarchal status (odds ratio = 2.5), osteopenia in the femoral neck of the hip on the side of the concavity (odds ratio = 2.3), and a younger age at the time of diagnosis (odds ratio = 2.1) were identified as risk factors in predicting curve progression. A predictive model was established, and the area under the receiver operating characteristic curve of the model was 0.80 (p < 0.01). CONCLUSION: Osteopenia may be an important risk factor in curve progression. The measurement of bone mineral density at the time of diagnosis may serve as an additional objective measurement in predicting curve progression in adolescent idiopathic scoliosis. The bone mineral density-inclusive predictive model may be used in treatment planning for patients with adolescent idiopathic scoliosis who are at high risk of curve progression.     

A new risk classification rule for curve progression in adolescent idiopathic scoliosis

Background context

Prognostic factors for curve progression of adolescent idiopathic scoliosis (AIS) have been reported previously. There is only one existing rule that classifies AIS patients into two groups by a curvature of 25°.

Purpose

This study aimed to develop a more refined risk classification rule for AIS.

Study design

This was a retrospective cohort study.

Patient sample

We examined 2,308 untreated AIS patients, aged 10 years and older, who had a Risser sign of 2 and lesser and a curvature less than 30° at presentation.

Outcome measures

Outcome was taken as the time to progression to 30°.

Methods

Patients' clinical parameters were analyzed by Classification and Regression Tree analysis.

Results

The new classification rule identified four risk groups of curve progression. Patients with a curvature of 26° and more and less than 18° constituted the highest and lowest risk groups, respectively. The two intermediate groups were identified by the age (11.3 years), menarcheal status, and body height (154 cm).

Conclusions

The risk classification rule only uses information at the first presentation and can aid physicians in deriving an efficient management.     

Predictive value of single-nucleotide polymorphisms in curve progression of adolescent idiopathic scoliosis

Purpose

Genetic diagnosis is a promising approach because several single-nucleotide polymorphisms (SNPs) associated with adolescent idiopathic scoliosis (AIS) progression have been reported. We review the predictive value of SNPs in curve progression of adolescent idiopathic scoliosis.

Methods

We reviewed DNA-based prognostic testing to predict curve progression. Then, the multiple polymorphisms in loci related to AIS progression were also reviewed, and we elucidated the predictive value of SNPs from four functional perspectives, including endocrine metabolism, neuromuscular system, cartilage and extracellular matrix, enzymes, and cytokines.

Results

The ScoliScores were less successful predictors than expected, and the weak power of predictive SNPs might account for its failure. Susceptibility loci in ESR1, ESR2, GPER, and IGF1, which related to endocrine metabolism, have been reported to predict AIS progression. Neuromuscular imbalance might be a potential mechanism of scoliosis, and SNPs in LBX1, NTF3, and SOCS3 have been reported to predict the curve progression of AIS. Susceptibility loci in SOX9, MATN1, AJAP1, MMP9, and TIMP2, which are related to cartilage and extracellular matrix, are also potentially related to AIS progression. Enzymes and cytokines play essential roles in regulating bone metabolism and embryonic development. SNPs in BNC2, SLC39A8, TGFB1, IL-6, IL-17RC, and CHD7 were suggested as predictive loci for AIS curve progression.

Conclusions

Many promising SNPs have been identified to predict the curve progression of AIS. However, conflicting results from replication studies and different ethnic groups hamper their reliability. Convincing SNPs from multiethnic populations and functional verification are needed.

     

Pulmonary function after thoracoplasty in adolescent idiopathic scoliosis

The current study evaluated sequential pulmonary function tests prospectively at a minimum of 2 years after thoracoplasty in adolescent patients with idiopathic scoliosis. Twenty patients were divided into two groups: Group I (n=12) was comprised of patients who had posterior instrumented fusion with external thoracoplasty, and Group II (n=8) was comprised of patients who in addition to a posterior instrumented fusion, had an anterior release and fusion via video-assisted thoracoscopic surgery (n=4) or open thoracotomy (n=4) because of rigid severity. Forced vital capacity and forced expiratory volume in 1 second of percent predicted values in Group I declined 9% at 3 months postoperatively and returned to the preoperative baseline at 1 year. However, forced vital capacity and forced expiratory volume in 1 second of percent predicted values in Group II declined 11% to 18% postoperatively and did not return to the preoperative baseline at 2 years. Posterior instrumented fusion with thoracoplasty in adolescent patients with idiopathic scoliosis significantly decreased pulmonary function at 3 months, but returned to the preoperative baseline at 1 year. The addition of an anterior releasing procedure resulted in poorer pulmonary function, which did not return to the preoperative baseline by the 2-year followup.     

Platelet function in adolescent idiopathic scoliosis.

Recent studies have reported abnormal platelet morphology and function in patients with adolescent idiopathic scoliosis. These abnormalities include increased platelet size and dense body numbers, abnormal aggregation, thromboxane A2 synthesis, serotonin release to adenosine diphosphate and epinephrine stimulus, and decreased myosin-adenosine-triphosphatase-specific activity. It was postulated that a membrane-specific defect in calcium transport may be partially responsible for the abnormalities found. In response to a suggestion in the literature that platelet screening could be clinically useful in scoliosis evaluation as well as in basic research of its pathophysiology, a study was performed to evaluate platelet morphology, biochemistry, and function in patients with adolescent idiopathic scoliosis. Platelets from nine volunteers with adolescent idiopathic scoliosis were compared with cells from a control group of nine patients. No significant differences in measured platelet parameters were noted between adolescent idiopathic scoliosis patients and control groups. Platelets from both groups demonstrated normal aggregation and release patterns with all agents except for a mild decreased aggregation and secretion response to epinephrine. No significant differences were noted in serotonin or adenine nucleotide levels. No significant ultrastructural differences were noted. Earlier findings of an abnormal aggregation and secretion response to adenosine diphosphate, increased numbers of dense bodies, or increased intracellular calcium could not be confirmed. On the contrary, we found normal, if not slightly decreased, numbers of dense bodies per platelet and calcium levels that were not different from controls.     

Role of the triradiate cartilage in predicting curve progression in adolescent idiopathic scoliosis

Braces are commonly used to treat progressive adolescent idiopathic scoliosis. Several previous studies have reported a correlation between the success of brace treatment and skeletal maturity markers. These studies have not focused on the status of the triradiate cartilage (TRC) as it relates to successful brace treatment for adolescent idiopathic scoliosis. The authors retrospectively evaluated all patients at their institution from 1990 to 1997 with a diagnosis of adolescent idiopathic scoliosis who were treated in a Boston brace. Sixty-two patients met inclusion criteria. At presentation, the average age was 12.87 years, the average Risser sign was 0.56, and 45% of patients had an open TRC. The average follow-up was 2.92 years. Greater than 5 degrees of progression at discontinuation of bracing was considered a failure. Curves with a closed TRC failed bracing 21% of the time, whereas those with an open TRC failed 54% of the time (P = 0.0069). Those curves with a closed TRC progressed 3.12 degrees on average, whereas curves with an open TRC progressed 6.86 degrees. Curves associated with a closed TRC at initiation of bracing progressed less frequently and to a lesser degree than those associated with an open TRC (P = 0.027). Although the TRC is not an independent predictor of curve stability, it is an additional indicator of skeletal maturity and may prove most useful in patients with otherwise borderline indications for brace treatment.     

女性青少年特发性脊柱侧凸患者停止支具治疗后的侧凸进展及其相关因素

目的 :分析发育成熟的女性青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)患儿在停止支具治疗后长期随访中的侧凸进展情况,并探讨其相关因素。方法:回顾性分析于我院门诊就诊符合SRS(scoliosis research society)支具治疗标准的女性AIS患儿130例,初诊年龄11.8±1.4岁(10~14岁)。所有患儿均随访至支具治疗结束后至少2年,且至少具有佩戴支具后初次随访、停止支具治疗时、停止支具治疗后6个月、1年、2年及末次随访时的资料。在每次随访时的全脊柱正位X线片上测量主弯侧凸Cobb角,并评估侧凸进展超过5°的患儿及比例、侧凸进展度数和进展速率。末次随访时侧凸进展超过5°定义为侧凸进展,采用独立样本t检验比较侧凸进展组和非进展组患儿的初诊年龄、月经初潮年龄、初诊Cobb角、初始矫正率、停止支具治疗年龄。结果:与停止支具治疗时相比,停止支具治疗后6个月、1年、2年及末次随访时的侧凸进展超过5°的患儿分别为33例(25.4%)、42例(32.3%)、61例(46.9%)和63例(48.5%);侧凸进展度数分别为2.0°±4.4°、3.2°±5.0°、4.9°±5.5°和5.1°±6.9°;侧凸进展速率分别为0.33°±0.71°/月、0.20°±0.41°/月、0.14°±0.29°/月和0.01°±0.19°/月。停止支具治疗后侧凸非进展组和进展组患儿的初诊年龄、月经初潮年龄、初诊Cobb角、初始矫正率、停止支具治疗时年龄等无显著性差异(P0.05),而停止支具治疗时的Cobb角有统计学差异(P0.05)。结论:行支具治疗的AIS患儿停止支具治疗后仍有较高的侧凸进展风险,停止支具治疗后的6个月内为侧凸进展高风险和高速率期;停止支具治疗时的侧凸Cobb角越大发生侧凸进展的风险越高。     

Changes in curve pattern after brace treatment for idiopathic scoliosis

We studied whether thoracic Boston brace treatment changes the King type of scoliotic curves in a group of 50 patients with adolescent idiopathic scoliosis. Bending radiographs showed more flexibility of the lumbar curves than that of the thoracic curves. However, after initial application of the brace, the mean lumbar correction in degrees was less than the mean thoracic correction. After brace treatment we found a slight statistically significant increase in the mean lumbar curve, but no significant change in the mean thoracic curve. In 7 of our patients, we found a change in the King classification which seemed to be related to insufficient lumbar correction at the start of brace treatment. When classifying idiopathic scoliosis, one should bear in mind that the result may be temporary because scoliosis is a dynamic process. A change in curve type can occur during brace treatment.     

Changes in curve pattern after brace treatment for idiopathic scoliosis

We studied whether thoracic Boston brace treatment changes the King type of scoliotic curves in a group of 50 patients with adolescent idiopathic scoliosis. Bending radiographs showed more flexibility of the lumbar curves than that of the thoracic curves. However, after initial application of the brace, the mean lumbar correction in degrees was less than the mean thoracic correction. After brace treatment we found a slight statistically significant increase in the mean lumbar curve, but no significant change in the mean thoracic curve. In 7 of our patients, we found a change in the King classification which seemed to be related to insufficient lumbar correction at the start of brace treatment. When classifying idiopathic scoliosis, one should bear in mind that the result may be temporary because scoliosis is a dynamic process. A change in curve type can occur during brace treatment.     

Predicting growth and curve progression in the individual patient with adolescent idiopathic scoliosis: design of a prospective longitudinal cohort study

Background  

Scoliosis is present in 3-5% of the children in the adolescent age group, with a higher incidence in females. Treatment of adolescent idiopathic scoliosis is mainly dependent on the progression of the scoliotic curve. There is a close relationship between curve progression and rapid (spinal) growth of the patient during puberty. However, until present time no conclusive method was found for predicting the timing and magnitude of the pubertal growth spurt in total body height, or the curve progression of the idiopathic scoliosis.     

Advances in scoliosis brace treatment for adolescent idiopathic scoliosis

Orthotic treatment with a brace remains the treatment of choice for adolescent idiopathic scoliosis in the immature patient with documented progression or a curve magnitude of 25 degrees to 40 degrees . Studies of natural history and bracing consistently show high rates of curve progression and surgery with observation and significantly less so with brace treatment. Brace treatment is difficult in overweight patients and challenging in males. Many of the variations in brace study results may be attributable to differing rates of compliance with brace wear, a parameter that is becoming easier to measure.     

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

Summary of background data

The curve pattern of idiopathic scoliosis is important for making decisions concerning bracing. However, whether the curve pattern changes during brace treatment have not been fully documented. The aim of this study was to investigate the changes of curve pattern during brace treatment in skeletally immature patients with adolescent idiopathic scoliosis (AIS).

Methods

From January 2002 to January 2011, AIS patients treated with a Boston or Milwaukee brace were recruited after meeting the following inclusion criteria: older than 10 years of age at initiation of bracing; having a Cobb angle of 25°–40°; with a Risser sign 0–2; being regularly followed until the weaning of brace or the necessity of surgical treatment; and without history of previous treatment. A total of 130 female and 11 male AIS patients were included. The mean age was 12.9 years at initiation of bracing, and the female patients were, on average, 2.7 months past menarche. The mean follow-up period was 2.6 years (range 1.0–5.5 years). The definitions of changes in curve patterns were divided into four categories as follows: (1) shift of the apex of the main curve; (2) change in the curve span of more than two vertebrae; (3) change in the main curve type with regard to the apex location; and (4) change of curve direction. The patients were divided into two groups. Group A was comprised of patients who had experienced one or more categories of curve pattern changes, and Group B was comprised of those who had not.

Results

Of these 39 patients, 14 had apex shifting, 2 underwent curve span changes, 22 experienced changes in the main curve type, and one female had both changes in the apex and curve span. At the initiation of bracing, patients in Group A demonstrated significantly lower menarchal status (P = 0.018) and lower Risser grade (P = 0.025) than those in Group B. The difference in the percentage of patients who underwent Boston bracing between the two groups was statistically significant (41.5 % for Group A vs. 24.0 % for Group B, P = 0.023).

Conclusion

Changes in curve pattern can occur during brace treatment. Patients with less skeletal maturity and those treated with a Boston brace are more susceptible to this phenomenon.     

Indications of proximal thoracic curve fusion in thoracic adolescent idiopathic scoliosis: recognition and treatment of double thoracic curve pattern in adolescent idiopathic scoliosis treated with segmental instrumentation

STUDY DESIGN: A retrospective study. OBJECTIVES: To determine the indications of fusing the proximal thoracic curve when treating idiopathic thoracic scoliosis with segmental instrumentation. SUMMARY OF BACKGROUND DATA: Failure to recognize a significant proximal thoracic curve often results in postoperative shoulder asymmetry due to relative overcorrection of the lower thoracic curve. With segmental instrumentation that enhances the correction of the instrumented curve, the double thoracic curve pattern that needs fusion of both the proximal and the distal thoracic curves should be redefined. METHODS: Forty patients with thoracic adolescent idiopathic scoliosis with a right lower thoracic curve of more than 40 degrees and a left proximal thoracic curve of more than 25 degrees treated by segmental pedicle screw instrumentation were analyzed after a minimum follow-up of 2 years. RESULTS: Of the 40 patients, 18 were treated by fusion of both the proximal and the distal curves, whereas 22 were treated by fusion of the distal curve only. The postoperative shoulder height difference (SHD, in millimeters) was 0.9 x preoperative SHD + 5.3 for the fusion of both curves and 0.6 x preoperative SHD + 12 for the distal curve fusion (linear regression), showing that proximal thoracic curve fusion improved the SHD when the left shoulder was level with or higher than the right. CONCLUSIONS: Idiopathic thoracic scoliosis with a proximal thoracic curve of more than 25 degrees and level or elevated left shoulder should be considered a double thoracic curve pattern and should be treated by fusing both the proximal and the distal curves when using segmental instrumentation.