Summary
Although the nonsurgical management of scoliosis has a history that extends back hundreds, if not thousands, of years, the interest and evidence supporting these treatment options has exploded in the last 10 to 20 years. Currently, there are three mainstays of conservative scoliosis treatment: bracing, scoliosis-specific exercise programs, and, more recently, medical treatment with supplemental vitamin D. All of these interventions have literature supporting their use, including randomized clinical trials. Bracing represents the workhorse of most nonoperative protocols, and recent advances in the brace design and materials have allowed for improved three-dimensional in-brace correction of scoliosis and what seems to be improving outcomes. Research is starting to show us optimal brace design and wear parameters. Scoliosis-specific exercise programs, although still not considered mainstream in much of North America, have gained a lot of respect and support in the last decade as a growing body of literature continues to demonstrate efficacy and the number of practitioners has increased dramatically. Although as yet unpublished, the data presented from the randomized clinical trial for vitamin D supplementation are very compelling, and this treatment should be considered for all patients.
Key words
brace – nonsurgical – nonoperative – scoliosis – Schroth – scoliosis-specific exercise – Vitamin D – compliance5 Nonoperative Management of Adolescent Idiopathic Scoliosis
“They also serve who only stand and wait.” –John Milton
5.1 Introduction
Although nonoperative management has been present from the earliest days of scoliosis treatment, in the last decade, we have witnessed an explosion in interest in the understanding and application of nonoperative modalities for children with adolescent idiopathic scoliosis (AIS). The treatment of any condition should take into account the short- and long-term outcomes, as well as the complications of that treatment modality. Until recently, bracing and surgery have been the only widely accepted treatment options for scoliosis, although various other proposed treatment modalities have been used. Techniques including electrical muscle stimulation, chiropractic manipulation, and magnet therapy have come and gone as evidence failed to support their use. However, since the previous edition of this book, there has been increasing evidence to support the use of physiotherapeutic scoliosis-specific exercises (PSSE) as well as vitamin D supplementation. Given that fact, this chapter will focus on these newer nonoperative treatment modalities for scoliosis.
5.2 Screening
Although surgical management of AIS has evolved dramatically with respect to efficacy and safety, the primary goal of treating a child with scoliosis should be to improve upon outcomes of natural history with the least burden of care. The formula to achieve this is straightforward—early detection and the initiation of an effective nonsurgical intervention. Though somewhat controversial, we feel that appropriate screening plays an important role in early detection and optimal treatment, especially given strong evidence supporting the efficacy of bracing. 1 A valid screening program for any condition requires two prerequisites: (1) it must have a screening tool that is valid, cost-effective, ethical, and acceptable to the subjects and (2) there must be a treatment option (or options) for that condition that can change the natural history. 2 Given the latest literature on the effectiveness of nonsurgical treatments, screening for AIS meets both of these requirements.
We are developing a better understanding regarding the risk of curve progression and therefore the indications for nonoperative treatment, though work remains to be done in this area. For example, curve progression is known to be most common in skeletally immature girls with curves measuring ≥30 degrees. 3 However, there is a paucity of data about small curves, including their progression potential and to what degree they constitute a serious health problem. The screening test used most widely for scoliosis is the Adams forward bend test, commonly performed by pediatricians and other primary care providers, as well as being mandated in schools by many state boards of education. 4 Viviani et al 5 found that nurses trained in the Adams forward bend test could detect curves of at least 20 degrees on radiographs with a sensitivity of 100% and a specificity of 91%.
Opponents of school screening cite concerns about the low predictive value of screening and the cost-effectiveness of referral. 6 Additional factors are the possibility of unnecessary treatment, including the use of a brace, and the effects of exposure to radiation during screening and follow-up. Costs involved in screening for scoliosis are relatively low on a societal level and may be justified by the avoidance of surgery in some adolescents with scoliosis. 7 Indeed, Sanders et al 8 found that for patients highly compliant to bracing, the number needed to treat to prevent one surgery was three; that is, you needed to treat three AIS patients with a brace to prevent one surgery. Similarly, Weinstein et al 9 found that the number needed to treat with bracing in order to prevent curve progression was three. Patients without significant spinal deformity referred to specialists do not require radiography, and for those who do, it is important to note that current radiographic techniques have reduced radiation exposure to 1/100th of that from conventional radiographic techniques used before the advent of digital radiography. 10
In 1993, Montgomery et al 11 published their work that strongly supported school screening for scoliosis. They demonstrated an eightfold decrease in the relative risk of curve progression into the surgical range in children who were screened. The authors concluded that screening decreased the number of surgical curves because curves were detected and braced when smaller, thus having a better prognosis. There is additional evidence supporting the accuracy of scoliosis screening programs. Luk et al 12 conducted a large retrospective study that determined that the positive predictive value of screening for spinal curvature greater than 20 degrees was 43.8%, whereas Fong et al 13 found a sensitivity of 91% for detecting curves greater than 20 degrees in a population-based cohort of 394,401 children.
However, not all of the data have been positive. Yawn et al 14 concluded that the positive predictive value of routine screening was low, whereas Morais et al 15 stated that the prevalence of scoliosis was too low to benefit from screening; they also expressed concerns about radiation exposure following clinical screening.
To date, no studies based on level one evidence have been done on school screening for scoliosis, and such a study is unlikely to be performed in the future. Based on this fact, the U.S. Preventive Services Task Force in 2018 concluded that the current evidence on the benefits and harms of screening is insufficient and therefore makes no recommendation either way. 16 This statement is a departure from a previous statement in 2004 that recommended against screening. 17 This change in opinion is largely due to the growing evidence of the efficacy of brace treatment in AIS. Although this is a move in the right direction, this new recommendation falls short of existing recommendations from other professional societies outlined in the 2015 position statement from the Scoliosis Research Society (SRS), American Academy of Orthopaedic Surgeons (AAOS), Pediatric Orthopaedic Society of North America (POSNA), and American Academy of Pediatrics (AAP), which argue for the use of routine screening examinations based on current evidence. 18 Although professional societies representing those who most commonly treat these children support screening, the literature remains somewhat inconclusive in this regard.
5.3 History of Bracing
This section will focus on the history of bracing including indications, brace types, and scientific evidence of effectiveness prior to 2014. We selected this time frame as the BrAIST study 9 was published that year, which dramatically changed attitudes toward bracing in North America. The following section will discuss this transformative study, flaws and all, and the literature that followed.
Indications: The primary goal of brace treatment of moderate scoliosis in growing children is to prevent or limit progression. Curves of less than 30 degrees rarely progress after maturity, but larger curves, especially in the thoracolumbar or lumbar region, have the potential to increase throughout the patient’s life. 19 Traditionally, bracing has been recommended for curves of ≥25 degrees in skeletally immature patients. Smaller curves are typically observed on a regular basis, often about every 6 months. The SRS has published guidelines for bracing indications to help develop consistency in research and minimize variability in a treatment modality that heretofore has been applied in a very heterogeneous manner. Their indications for initiating brace treatment are age ≥10 years, Risser grade 0 to 2, primary curve 25 to 40 degrees, and girls should be premenarchal or less than 1 year postmenarchal. 20
It should be noted that other indications for bracing exist with some support in the literature. For example, a recent prospective cohort study found evidence that bracing could not only prevent progression but also result in some improvement in Cobb angle in growing children with curves greater than 45 degrees. 21 Additionally, Wiemann et al 22 demonstrated that nighttime bracing of smaller (15- to 25-degree) curves in the high-risk, skeletally very immature patient (Risser grade 0) prevented curve progression and the need for full-time bracing in about one in four patients, compared to the 100% rate of progression seen in the control group.
Mechanism of action: It is thought that brace correction of spinal curves occurs through holding the spine, trunk, and rib cage in a corrected position during growth. Different braces affect correction differently utilizing transverse, bending, and rotational forces. However, the way these braces apply these forces, and the resultant curve correction, can have an additive effect in improving critical load and stabilizing a curve. 23
Goals of bracing: Full-time bracing instituted early and with a well-fitting brace may reduce the size of a curve during the treatment period, but this correction does not typically persist after bracing is discontinued at skeletal maturity. Lasting correction is occasionally seen, especially in the very skeletally immature (typically with open triradiate cartilage); the consensus among centers with a long track record of bracing is that the expected outcome of bracing is the prevention of further deformity. This should be clearly communicated to the family to prevent disappointment from unrealistic expectations as many expect their child to look the way she looks in the brace after bracing has been discontinued.
5.4 Types of Braces
Rigid braces: The Milwaukee brace was developed by Blount and Moe in the late 1940s as a substitute for postoperative casting in scoliosis and was then adapted for use in the nonoperative treatment of neuromuscular and idiopathic scoliosis. This cervicothoracolumbosacral orthosis (CTLSO) consisted of a molded pelvic girdle that was attached to a metal superstructure that supported lateral pads, trapezial pads, and, in some cases, axillary slings (for curves with an apex above T7). Initially, an occipital attachment and throat mold was used to stabilize the head and create traction forces, but the effectiveness of this component was later disproven and its use was discontinued. 24 Compliance with the Milwaukee brace was poor—it was bulky, uncomfortable, and completely obvious to the patients’ peer group. Thus, it is rarely, if ever, prescribed anymore, and few orthotists working today have ever made one. It is mentioned here for historical context.
The Boston brace system was developed at the Children’s Hospital of Boston in the 1970s and consisted of six standard, prefabricated polypropylene pelvic and thoracolumbar modules lined with polyethylene foam. The pelvic module is trimmed on the basis of X-ray findings and pressure pads are added at the apex of the curve(s). 25 Lumbar lordosis is reduced by flexing the lumbar spine. The decrease in lumbar lordosis places the facet joints into a less tightly apposed orientation allowing for correction and movement in the axial plane. For curves with a high apex, an axillary support can be added on the concave side with lateral pressure from a pad on the convex side. Today, the Boston brace remains the most commonly used brace for AIS worldwide, now with more than 16 prefabricated modules available. It should also be noted that more modern Boston braces attempt to preserve normal lumbar lordosis and look to correct the axial component of deformity as well.
The Wilmington brace was developed by Bunnell et al 26 at the Nemours/Alfred I. duPont Hospital for Children in Wilmington, Delaware, as another alternative to the Milwaukee brace. Fashioned from Orthoplast, the total-contact custom jacket of this brace is made from a custom mold of the patient with the patient on a Risser table that allows the application of transverse, derotation, and traction forces to hold the curve in a maximally corrected position. While applying the mold, transverse forces are applied at the apices of the curves while maintaining spinal balance and curve correction of at least 50%. Trim lines are cut high in the axilla and low over the pelvis but are designed to allow the patient to sit. An opening is cut in the front of the brace with an overlap that allows the patient to don and doff the brace over a cotton or synthetic fiber undergarment. Compliance with the Wilmington brace has been high, likely due to the intimate fit of the brace, convenience of its wear, and thin material (3.2 mm) of which it is made. Although the breakdown of the Orthoplast material has been seen as a relative disadvantage of the Wilmington brace, this deterioration does provide good evidence of compliance. Patients who wear the brace full-time need an average of three fabrications. 27
The Rigo–Chêneau-type brace is a three-dimensional (3D) thoracolumbosacral orthosis (TLSO) that was developed in 1979 by Drs. Jacques Chêneau and Manuel Rigo to provide correction in three dimensions, including curve derotation using a variety of curve specific brace designs. The brace was designed to replicate the curve correcting posture instructed in scoliosis-specific physical therapy programs such as Schroth by providing both a derotational force over the posterior rib prominence and room anteriorly for the chest to move into. As opposed to the traditional Boston braces, which intentionally reduced lumbar lordosis (it was thought this allowed them to better correct the deformity by opening up the facet joints), the philosophy of the Rigo–Chêneau brace stresses the importance of sagittal alignment and the preservation of lumbar lordosis. The Rigo–Chêneau brace attempts to recreate the normal sagittal alignment of the spine as closely as possible.
The Rigo–Chêneau-type brace is constructed mainly using two different techniques. 28 The first and original technique involves modeling a thermoplastic structure on a corrected positive plaster model. Unlike the symmetric Boston brace, the corrective forces of Rigo–Chêneau-type braces are incorporated directly within the positive cast model and designed according to the patient’s individual curve pattern. The second technique utilizes computer-aided design/computer-aided manufacturing (CAD/CAM). An orthotist may use an extensive predesigned library of CAD/CAM molds that are individually selected based on patient characteristics. A study performed by Rigo et al 29 compared in-brace curve correction of patients treated with the authors’ handmade braces to that of patients treated with CAD/CAM braces produced from precorrected molds. They found that the in-brace curve correction achieved by CAD/CAM Rigo–Chêneau-type braces were as effective as handmade braces built by the original author of the Rigo–Chêneau brace; the handmade group had a major curve correction of 53.7% compared with 52.6% in the CAD/CAM group.
Other TLSO types of braces, constructed from more durable polypropylene, include the Miami brace, Rosenberger brace, Providence brace, and Charleston bending brace. The Charleston brace was originally developed as an alternative to full-time brace wear for single thoracolumbar or lumbar curves. During the production of this brace, the orthotist maintains pressure over the apex of the patient’s scoliotic curve while applying a bending force above the curve. More than 75% curve correction is considered adequate. The Charleston and Providence braces are intended for nighttime wear only because of the awkward positioning of the patient in the brace. One prospective study demonstrated similar rates of progression between the Providence and full-time Boston braces for curves with apices at or below T10. 30
Flexible braces: Nonrigid braces, often called dynamic corrective braces, were first described in the late 19th century. However, the modern design that is in use today was developed in Montreal in the 1990s, with the first published reports coming out about a decade later. 31 These devices work with flexible straps to help hold the curve in a corrected position. This brace was developed in part to improve compliance; it may or may not be more comfortable than its rigid counterparts. There has been a lot of controversy about these devices and the supporting literature, as discussed below.
5.5 Evidence for Bracing
Modern bracing has been instituted since the end of World War II, and the literature of the past few decades overwhelmingly finds that bracing changes the natural history of AIS. The classic 1994 study by Lonstein and Winter 32 studied over 1,000 patients with AIS, all treated with a Milwaukee brace, and compared them with a natural history group of 729 patients seen at the same hospitals. This study showed that bracing had a significant positive effect on the natural history of AIS (p = 0.0001). In the critical high-risk group of girls of Risser grade 0 to 1 with thoracic curves of 20 to 40 degrees, there was a failure rate (defined as progression of 6 degrees or more) of 43% with bracing as compared with a rate of 68% in the natural history control group. This study confirmed the results of another Milwaukee brace study published in 1988 by Durand 33 on 477 AIS patients. In this study, the highest-risk group, defined as Risser grade 0 or 1, had a 21% failure rate in braced patients compared with the 68% failure rate in the natural history group (at 5 years after skeletal maturity).
Fernandez-Feliberti et al 34 published their results comparing 54 compliant patients treated with a rigid custom TLSO with 47 untreated age-, gender-, and curve-matched patients. Similar to the Milwaukee literature, there was a threefold greater frequency of surgery or major curve increase in the control group compared to the brace-treated group.
Results with the Wilmington brace for the nonsurgical treatment of AIS are also favorable. The initial report by Bunnell et al 26 on 48 patients treated with this device showed an in-brace curve correction of 74%, and only 10% of patients had curve progression of 5 degrees or more. Bassett et al 35 reported on 79 patients with curves of 20 to 39 degrees, Risser grade 1 or 0, with an in-brace correction of 50%: only 28% had curve progression of greater than 5 degrees at a mean follow-up of 2.5 years. In a subsequent report on these patients at 8 years of follow-up, there was additional curve progression but only 12% progressed to surgery. 36
Emans et al, 37 in 1986, reported their initial results with the Boston TLSO in 295 patients at an average follow-up of 1.4 years after the discontinuation of bracing. Curve progression of ≥5 degrees was noted in 7% of the patients during treatment, and only 11% of the patients went for surgery. Patients with low apex curves did best, whereas patients who were young at brace initiation or had larger curves were at increased risk of surgery. Similar to the findings of the Wilmington group, Emans et al noted that initial brace correction of at least 50% correlated with better results.
A dynamic brace, using straps to provide transverse and rotational corrective forces, was developed in Montreal by Rivard and colleagues and is now manufactured under the name SpineCor. Of the 170 patients followed to maturity after treatment with the SpineCor brace, 59% had no progression of spinal curvature during the treatment period. Forty-two patients (26%) required surgery because of curve progression or had curves greater than 45 degrees at maturity. 38 Whereas this study indicated that this dynamic brace was better than natural history, comparisons to rigid braces have not been as positive. A randomized, controlled trial (RCT) conducted by Guo et al 39 that randomized patients to SpineCor or a rigid orthosis found that 68% of patients in the SpineCor group versus 95% of the patients in the rigid orthosis group did not show curve progression, demonstrating that the failure rate of the SpineCor was significantly higher than that of a rigid spinal orthosis.
The first prospective controlled study of brace treatment for scoliosis was published in 1995 by Nachemson and Peterson. 40 In this long-term multicenter study sponsored by the SRS, 10 institutions from around the world, each espousing one of three different treatment philosophies, were pooled as a surrogate to randomization. Several institutions did not believe in bracing and simply observed their patients (the natural history group), whereas other institutions either used rigid bracing or performed electrical stimulation. Ultimately, 247 female patients were followed to maturity and formed the basis of this study. Whereas the results with electrical stimulation were no different from those for the natural history group, the investigators were able to show that bracing significantly altered the natural history of AIS (p < 0.0001). Curve progression of ≥5 degrees was noted in 26% of the patients treated with braces, 67% of the electrical stimulation group, and 66% of the natural history group, demonstrating a clear advantage of bracing.
Another prospective controlled study provided evidence for the effectiveness of bracing in patients with a curve of ≥45 degrees. Lusini et al 21 reported that 100% of patients in the observational control group had curve progression of at least 5 degrees, whereas progression occurred only in 23.5% of the bracing group.
Regarding bracing exposure, many initial studies asked their patients to wear the brace 23 hours a day with 1 hour reserved for bathing and exercises. 37 , 41 , 42 , 43 , 44 However, this protocol of full-time brace wearing (23 h/d) is difficult and compliance low, so many centers have modified this to 16 hours a day 27 , 45 without finding any appreciable differences in the risk of progression. A meta-analysis of the literature 46 found a relationship between the duration of brace wearing per day and prevention of curve progression, suggesting that the more time a patient spends in a brace the less likely is the patient’s curve to progress. Rahman et al 47 corroborated this in a study that showed that more compliant patients had a favorable outcome with brace treatment using the Wilmington TLSO.
Despite the apparent plethora of evidence for brace treatment, these studies have their shortcomings. Few of them objectively evaluate “exposure or dosage” (hours in the brace) outside of patient reporting, which is known to be unreliable. Additionally, few have any true randomization and are open to a variety of biases. With regard to the dynamic braces, all of the positive studies were published by the group that developed the brace, which raises obvious questions.
The most recent, and arguably the best, evidence for the effectiveness of bracing and this dose–response relationship of hours in brace and decreased curve progression came from the BrAIST trial performed by Weinstein et al, 9 which will be discussed next.
5.6 BrAIST and Factors Impacting Brace Success
As we have seen, prior to 2013, although the research on bracing was generally quite supportive of bracing, it was challenged with methodological flaws, which limited its impact. Although most orthopaedists utilized bracing, they generally approached it with the attitude that it might help, it does not really hurt, and we do not have anything else to offer. This lack of confidence likely did not encourage great compliance with bracing, something that is difficult under the best of circumstances. The equipoise in North America surrounding bracing was disrupted by Stuart Weinstein and his colleagues with their randomized trial published in JAMA known as BrAIST, an acronym for Bracing in Adolescent Idiopathic Scoliosis Trial. 9 The BrAIST trial enrolled 116 patients who agreed to randomization and another 126 patients who chose their own treatment. This second group was included to increase numbers due to the difficulty with recruitment into the randomization arm. The inclusion criteria were skeletally immature patients with AIS between 20 and 40 degrees, and the outcome was the Cobb angle at skeletal maturity. Specifically, they looked at the ability of the brace to prevent progression to 50 degrees, thus preventing a surgical indication. There were several important conclusions drawn from this study, the most significant of which was that bracing works to prevent progression to surgery. When analyzing the intent-to-treat group (the 116 randomized patients), 75% of the braced group avoided progression to 50 degrees, compared to only 42% of the observation group. The as-treated analysis was similar with 72% of braced patients achieving a successful outcome versus 48% of the control group. As this analysis demonstrated that bracing is an effective intervention that reduces the number of children with AIS being indicated for surgery, the study was stopped by National Institutes of Health (NIH) reviewers prior to completion as it was felt to be unethical to continue, given the demonstrated benefits of bracing.
However, it should be noted that this trial is not without problems. A 2015 Cochrane review of bracing in AIS 48 found the quality of all studies on bracing to be low or very low, including the Weinstein study. One of the main problems with the BrAIST study was the difficulty enrolling patients—about 90% of the adolescents either refused to participate or refused randomization. This opens up the possibility of an unknown selection bias, which is why the Cochrane review gave this study a low-quality rating. Despite these issues, all other studies in the review were rated even lower (very low quality), and even though there is room for improvement and additional research, the BrAIST study has led to a major shift in physician attitudes toward bracing in North America. Additionally, it is unlikely at this point in time that enough equipoise exists to ethically justify another randomized clinical trial.
Currently, there is general agreement that bracing is more effective than observation, as supported by the vast majority of evidence. Subsequently, there has been a growing literature looking at factors surrounding bracing such as the impact on quality of life, as well as patient characteristics (both physical and psychological/emotional) and radiographic curve characteristics that impact brace compliance and effectiveness. We will discuss those below.
5.6.1 Factors Impacting Brace Effectiveness
In-brace curve correction seems to be a critical factor, with greater in-brace curve correction being associated with improved outcomes. 49 , 50 Although definite thresholds have not been established, the existing literature cites values between 30 and 50% correction as thresholds below which the likelihood of brace success diminishes.
Along with in-brace correction, compliance is a vital variable affecting brace outcomes. The best brace in the world cannot work if it is not worn, and worn properly. There are a handful of studies with objective brace monitoring (such as thermal probes) showing a relationship between time in brace and effectiveness but, as mentioned earlier, the data from BrAIST is probably most impactful. They found 12.9 hours to be a critical threshold value, below which bracing became much less effective. 9 A slightly smaller study out of Germany had similar findings. 51 They found that patients with less than 12 hours of brace time had significantly more curve progression than those braced for 12 to 16 or greater than 16 hours. Interestingly, they found no significant difference between the 12- to 16-hour group and the greater than 16-hour group. Two other studies looked at the impact of adherence on brace success, defined as the percentage of the time the patient wore the brace the prescribed number of hours. Both studies showed that lower compliance (defined as 70% in one study 52 and 50% in another 53 ) resulted in significantly greater progression.
Interestingly, the brace monitors have been shown to be able to impact compliance in at least two studies. Both of these studies demonstrated that patients who knew they had compliance monitors embedded in their braces had significantly better results than those who did not. In the study by Karol et al, 54 60% of patients counseled as to the purpose of their monitors did not have progression of their curve compared to 46% of the uncounseled group. Miller et al 55 did not look at outcomes, just compliance, but showed that patients who knew about their monitor were compliant 86% of the time, compared to 56% of those who did not, and wore their braces an average of 5.25 hours more per day.
The location of the major curve (defined as the largest curve) also has been demonstrated to have an impact on brace success. Defining success as prevention of progression to surgery or a Cobb angle of 50 degrees, Thompson et al 56 found that major thoracic curves had worse outcomes compared to major lumbar curves. Their retrospective cohort study of 168 patients found that 34% of major thoracic curves progressed to surgical indications, compared to 15% of major lumbar curves. When they looked specifically at those patients documented to be compliant with their brace (using the BrAIST definition of >12.9 h/d), progression was noted in 30% of major thoracic curves and only 5% of lumbar curves. One of the limitations to this study is one that permeates all studies—there are so many variables for which to control that the n values get too small to show meaningful differences. When they tried to control for skeletal maturity (by Risser sign), even though they found more failures in the Risser grade 0 group, they could not show significance due to the small numbers. This was especially true for the major lumbar curve group that started with only 39 patients.
Curve magnitude is another factor that is very impactful on the likelihood of curve progression with all studies that look at this factor showing better outcomes for smaller curves. 9 , 31 , 54 , 57 , 58 , 59 However, even larger curves can be amenable to bracing—a recent observational trial out of Italy 21 showed good results in curves greater than 45 degrees, with only 23% of patients treated with bracing and scoliosis-specific physical therapy progressing, compared to the 100% progression seen in the control group.
Skeletal maturity has long been known to be a risk factor for progression of scoliosis. 9 , 31 Most of the literature uses the Risser score as a marker of skeletal maturity, despite evidence that it can be relatively insensitive to identifying the adolescent growth spurt 60 and even significantly misrepresents growth remaining in nearly 25% of patients. 61 Despite these problems, it is clear the Risser stage correlates with the remaining growth; especially when the triradiate cartilage is still open, patients who are Risser grade 0 have significant growth remaining. Studies have indicated that patients who are Risser grade 0 have worse bracing outcomes than those who are Risser grade 1 or above. 54 , 56 This is not that surprising on the face of it as more growth increases the risk of progression, but the study by Karol et al 54 seemed to indicate that bracing was completely ineffective for the subgroup of patients with open triradiate cartilage; they found that similar percentages of patients progressed to surgery whether they wore their brace 18 hours a day or not at all. This was in contrast to the patients who were Risser grade 0 with closed triradiate cartilage who seemed to respond to a high-dose brace regimen (18 h/d). 54
Body type has also been found to modulate the effectiveness of bracing for AIS. High body mass index (BMI) has been associated with worse outcomes in a variety of conditions, and bracing for AIS is no exception. Patients with BMI over the 85th percentile have been shown to have a less in-brace correction, more progression, and worse compliance compared to their normal-weight peers. 62 Interestingly, there is also evidence that underweight adolescents may have even worse outcomes with high rates of refusal to wear their brace and increased risks of curve progression and surgery. 49
5.6.2 Psychosocial Effects of Bracing
Although bracing has been shown to result in a higher quality of life after treatment, 63 it seems intuitive that brace wearing can be a traumatic experience for adolescents that only adds to the psychosocial distress imposed by having a potentially disfiguring condition. However, in reality, evidence for the adverse psychosocial effects of bracing is mixed. Pham et al 64 found that brace wearing resulted in significantly decreased psychosocial functioning, sleep quality, and body image. Numerous other authors have published evidence that brace wearing decreases aspects of psychological well-being and increases stress as compared with that of AIS patients undergoing observation only. 65 , 66 , 67 , 68 Conversely, many studies indicate that the impact of bracing on patients’ well-being may not be as severe as previously thought. Schwieger et al 69 found that brace treatment did not reduce body image or quality of life in adolescents with AIS. Other studies have corroborated this finding, demonstrating no differences in body image and psychological and emotional distress between braced and nonbraced patients. 70 , 71 The dynamic brace literature provides additional data indicating that rigid braces are well tolerated. One of the stated advantages of the dynamic braces was improved compliance and better acceptance by patients with fewer adverse psychosocial effects. However, two recent studies found that the psychosocial outcomes were better in patients with rigid braces compared to the dynamic braces. 72 , 73 A third study using thermal probes also found that compliance was better in rigid braces than in dynamic braces. 74
Another important factor to consider is that adolescents with scoliosis, independent of brace use, experience decreased quality of life and body image compared with healthy peers, with worse outcomes correlated with larger Cobb angles. 75 , 76 Adolescents with scoliosis are also more likely to consume alcohol and have suicidal ideation. 76 Furthermore, as impairment on quality of life caused by AIS increases, compliance with brace wearing has been demonstrated to decrease. 77 Intervention in the form of individual and group support sessions has been shown to improve body image, compliance, and attitudes toward bracing. 78 Given the necessity of compliance with bracing for favorable outcomes, 9 providers should be aware of, and actively address, the psychological factors that contribute to decreased bracing compliance.
Physiotherapeutic scoliosis-specific exercise (PSSE): The International Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT) is the most influential organization focusing on nonoperative treatment of scoliosis. The most recent SOSORT guidelines state the goals of nonoperative intervention of AIS as (1) stop curve progression at puberty, (2) prevent or treat respiratory dysfunction, (3) prevent or treat spinal pain syndromes, and (4) improve aesthetics via postural correction. 79 Although in North America, bracing is the best studied and most common active intervention, there is a growing body of evidence to support the use of physical therapy. Nonoperative SOSORT has sponsored much of the research in this area and recommends the use of PSSE as an effective means of management. 79 PSSE consists of very specific exercises developed based on a detailed assessment of the patient’s curve pattern characteristics in all three planes. Patients are trained to “autocorrect” or “self-correct” their alignment in all three planes: coronal, sagittal, and axial. This corrected alignment is then incorporated into stabilizing exercises as well as balance, coordination, and proprioceptive training to automatize the more centered alignment. Patients are taught to incorporate the corrected alignment into activities of daily living.
Although PSSE and general or conventional physical exercise both work on core and posture strengthening, conventional therapy does not take into consideration the individual’s specific scoliotic curve pattern, and conventional therapists have not undergone specific education and certification in scoliosis assessment and management. 80
The role of physical exercise in the management of AIS has historically been met with differing opinions based on geography as well as clinical training. Although practitioners in European countries have long utilized physical exercise in the management of AIS, those in North America have been less inclined to advocate for exercise as a regular component of nonoperative scoliosis treatment. 80 , 81 , 82 The reasons for this are likely multifactorial. PSSEs originated in Europe where they have been widely researched and incorporated into standard practice for clinicians there. In contrast, there is a paucity of scoliosis-specific education in entry-level physical therapy curricula in North America (and in orthopaedic training programs), which leads to a lack of awareness and knowledge around best practices in treatment; ultimately, PSSEs are part of the culture of managing AIS in Europe but not in North America. Second, in European countries, there is much more comanagement of AIS by orthopaedic surgeons and physiatrists, whereas in the majority of North America, physician management of AIS falls to orthopaedic surgeons. This obviously leads to a greater opportunity for therapy to play an active role in the treatment of these patients in Europe. Finally, there was a long period of time where research was not being performed on physical exercise or PSSEs. From 1940 to 2005, although greater than 10,000 English language peer-reviewed articles were published on the surgical treatment of AIS, fewer than 100 publications (<1%) explored exercise as a potential intervention in treating scoliosis of any age (including adults). 83 Although the literature on PSSEs is growing, the historical paucity of published research undoubtedly has affected the consideration of physical exercise as a treatment option.
As mentioned earlier, the evidence around PSSEs is emerging, demonstrating its role in preventing progression of AIS (both as a standalone intervention and as an adjunct to bracing), as well as a tool to optimize surgical intervention (so-called pre-hab). The 2016 SOSORT guidelines for the orthopaedic and rehabilitation treatment of idiopathic scoliosis during growth has put forth 12 recommendations for the use of PSSEs to prevent scoliosis progression during growth. 79 One of these recommendations is supported by level one evidence, which states that PSSE is recommended as the first step to treat idiopathic scoliosis to prevent/limit the progression of the deformity and bracing. This recommendation is made for patients with AIS with small curves not yet in bracing range and is supported by at least one RCT. Monticone et al 84 in 2014 demonstrated Cobb angle improvement by 5.3 degrees in 55 immature patients with AIS with an average age of 12.5 ± 1.1 years, an average Cobb angle of 19.3 ± 3.9 degrees, and a mean Risser score of 0.55 treated with PSSE and followed until skeletal maturity. Improvements remained stable 1 year after skeletal maturity.
Systematic reviews on physical exercise for the treatment of idiopathic scoliosis published over the last decade have concluded that low- 85 , 86 , 87 to moderate-quality 88 evidence supports using exercise to affect the Cobb angle, angle of trunk rotation, and quality of life. All of these reviews highlight the necessity for stronger methodology, but it should be noted that the quality of the PSSE literature is at least as strong as that for bracing.
When using physical exercise/PSSE as an adjunct to bracing, the guidelines report level two evidence to support the use of PSSE during brace treatment to promote brace compliance. The RCTs of Schreiber et al 82 , 89 demonstrated the positive effect of PSSE added to the standard of care in AIS on Cobb angle, self-image, and back extensor strength. The prospective study design of Kwan et al 90 with a historical cohort-matched control group found that PSSE added to bracing led to increased Cobb angle improvement and stabilization of curves and less curve deterioration when PSSE + bracing was compared to bracing alone.
Since the publication of the SOSORT guidelines, there are at least three additional RCTs in process. 79 Additionally, there is increased discussion around the realities and difficulties in conducting RCTs in this patient population due to ethical reasons and high rates of patients/families not accepting randomization to a control arm of a given trial. 10 , 79 In addition to efforts around RCT study designs, efforts to produce high-quality observational studies may bypass the difficulties of an RCT design and also allow for better generalizability of results to the realities of clinical practice. 79 In summary, although arguments about the quality of the evidence can be made, there is little question that the vast majority of evidence supports a role for PSSEs in the management of AIS. Ongoing research, including studies from North America, 89 will help better define the indications and role for this mode of management.
Chiropractic treatment: As many as one in three people seek chiropractic opinions and treatment for their spinal deformities. Although a variety of techniques have been described, 91 there are two treatment programs that have found commercial success in the United States, the CLEAR method and ScoliSmart. Both methods involve intense therapy, 3 to 5 days per week to start, with a daily home program. Interventions include manipulative techniques (adjustments) and exercises addressing balance, posture, and equilibrium. Soft or hard bracing can be included as well.
However, there are little data to support the efficacy of chiropractic care for treating AIS. In 2017, Morningstar et al 91 took a critical look at the 2000 to 2016 scoliosis treatment and outcome (pediatric and adult patients) literature in the chiropractic database (www.chiroindex.org) and in PubMed. Of the 27 studies identified, there were 15 case reports, 10 case series, 1 prospective cohort, and 1 RCT. Only 2 of these 27 studies had any data reported using criteria recommended by SOSORT and the SRS Nonoperative Management Committee consensus paper. 92 Another paper within the chiropractic literature recognized that although some studies have demonstrated short-term benefits, these are not supported by longer-term follow-up studies. 93
A more recent study from Morningstar et al 94 reported a retrospective case series of 60 patients followed until at least Risser grade 3, their approximation of the end of growth. Their treatment protocol included a combination of in-office treatment with traction and manipulation as well as scoliosis-specific exercises. In addition, patients were instructed to perform 1 hour of daily home exercise. This study did utilize SOSORT guidelines for reported outcomes, making it stronger than most. The average starting curve was 32 to 34 degrees, and they found that about half of their patients documented improvement of their scoliosis by an average of 12 degrees over the course of treatment, whereas only 10% progressed at least 6 degrees. The improvement in measured Cobb angle would certainly represent an improvement from natural history, and certainly there are case reports of other scoliosis-specific exercise programs achieving this. Unfortunately, there are problems with this study. Using Risser grade 3 as a surrogate for end of growth is erroneous and, in fact, the Risser grade has been shown to misrepresent growth remaining in about 25% of patients. 61 Only about one-third of these patients achieved Risser grade 5, a level that would be generally agreed upon to represent skeletal maturity, and they reported results of patients who only achieved Risser grade 2. Other issues include no comparison group and no discussion as to what happens after exercises are stopped, or if it is recommended that all patients continue exercises indefinitely.
Ultimately, although it is an improvement over previous studies with more rigorous outcomes, this study follows the pattern of previous studies that demonstrate that intense scoliosis-specific exercises under the direction of a chiropractor with traction and manipulation can result in good short-term results. This is similar to what is seen in the physician and physiotherapist-based PSSE literature, but with the addition of manipulation and traction and more intense home exercise requirements. It is unclear whether the addition of chiropractic manipulation and traction provides an additive benefit.
In summary, chiropractic care is widespread in the United States and embraced by many seeking scoliosis treatment options. Although the data would suggest that SSEs done under the guidance of a chiropractor may have similar outcomes to those done under the guidance of a physical therapist or physiatrist, the paucity of evidence-based outcome data for scoliosis-specific chiropractic care makes it ultimately difficult to recommend these alternative treatments.
The role of vitamin D and calcium: The association between AIS and osteopenia has been well documented, with up to 38% of patients below –1 standard deviation of normal bone mineral density (BMD). 95 , 96 , 97 , 98 , 99 , 100 , 101 Furthermore, the BMD of patients with AIS has been shown to be on average 6.5% lower than that of controls, 99 and osteopenia has been implicated in the etiology of AIS. 102 This generalized osteopenia has significant implications for the treatment of AIS due to the association of osteopenia with curve severity. Lee et al 103 examined a cohort of 919 patients with AIS and found that curve severity was inversely related to BMD. More recently, cortical bone density has been identified as a significant prognostic indicator for curve progression. Yip et al 104 found that AIS patients with low bone density were more than twice as likely to progress to greater than 45 degrees.
Vitamin D deficiency in patients with AIS has been increasingly reported in the literature, with below normal levels in up to 75% of patients. 105 , 106 , 107 , 108 Although a generalized vitamin D deficiency in the pediatric population has been well documented, 109 patients with AIS have significantly lower vitamin D levels than do healthy controls. As with osteopenia, vitamin D levels negatively correlate with Cobb angles in AIS. 106 , 107 Furthermore, as vitamin D levels positively correlate with BMD in healthy adolescents, 110 vitamin D deficiency is believed to play a role in the pathogenesis of AIS and is speculated to influence its severity.
A recent double-blinded, RCT conducted by Lam et al 111 demonstrates the significant effect that calcium and vitamin D can have on the natural history of AIS. In this trial of patients with AIS between 20 and 40 degrees, 48.6% of patients with low levels of vitamin D progressed when given placebo versus 16.2% of patients given high levels of daily calcium and vitamin D supplementation. When stratified by baseline calcium intake, 54.3% of those with low baseline intake progressed when given placebo versus 19% of those given high levels of daily calcium and vitamin D. Notably, no difference in curve progression was found between the placebo and supplementation groups for those with normal baseline levels of vitamin D or normal levels of baseline calcium intake. This evidence for the effectiveness of vitamin D and calcium supplementation on preventing curve progression in AIS strongly suggests the need for further research in this area. Recruitment for a clinical trial assessing the effectiveness of 500 mg of calcium and 800 IU of vitamin D per day versus placebo at preventing curve progression in skeletally immature females with smaller curves (Cobb angles from 10 to 20 degrees) is ongoing by Lam et al in Hong Kong.
5.7 The Authors’ Recommended Treatment Method
The nonsurgical management of patients with AIS can involve many components including medication, bracing, and therapy. We feel it is important to discuss the indications and implications of each of these elements with the patient and their family to come up with the best comprehensive plan.
Vitamin D and calcium: We recommend vitamin D and calcium supplementation to every patient who comes into the office with AIS. The majority of children in this country are deficient in vitamin D, and the further north they live, the more true this becomes. Although the available evidence suggests that this intervention is most effective in children who are vitamin D deficient, given the high incidence of deficiency and the nonrisk of supplementation, we feel this is an appropriate intervention for all. This is probably as important a recommendation as we can make to our patients regarding their lifelong bone health, and we equate it to recommending that everyone wear a seat belt.
5.8 Bracing
Brace type, indications, and prescription: Protocolling brace treatment becomes rather complicated due to the myriad variables involved: curve size, skeletal maturity, brace type, patient temperament, family history, etc. We agree with the preponderance of evidence that bracing changes the natural history and that rigid bracing is superior to dynamic bracing. Although there is no good evidence demonstrating the superiority of any one specific rigid TLSO over any other, we prefer the Rigo–Chêneau brace. In our practice, we have found that we can effect more in-brace correction with this brace than other TLSOs, and this has been shown in multiple studies to be associated with better outcomes. 26 , 35 , 37 , 112 Additionally, the Rigo–Chêneau brace better preserves the sagittal profile than the Boston brace—specifically lumbar lordosis—and there is evidence to suggest that a mismatch between the pelvic incidence and lumbar lordosis is associated with higher rates of brace failure (curve progression). 113 , 114
In general, we recommend initiating bracing to children with AIS with curves between 20 and 45 degrees who are Sanders grade 3 to 5. We feel strongly that Sanders staging is superior to Risser staging with regard to evaluating skeletal maturity, growth remaining, and growth velocity, as there is evidence that Risser staging over- or underestimates growth remaining up to 25% of the time. 61 Once the brace has been fabricated and delivered, there is a “break-in” period of 4 to 6 weeks during which the patients increase their hours in the brace to the goal, typically 16 to 18 hours. Although there is a clear dose–response curve between hours in brace and effectiveness, compliance is challenging the more hours are recommended, and there are several studies showing good outcomes with as few as 12 to 13 hours a day in the brace. 9 , 115 , 116 Being able to spend 6 to 8 hours a day out of the brace allows children to continue their usual activities regardless of how active they may be, improves compliance, and is generally embraced by patients and their families. 51
Brace monitoring and cessation: After the break-in period, they return for an in-brace anteroposterior (AP) and lateral full spine radiograph to measure the in-brace curve correction (with a goal of 30–50% correction). We typically have our orthotist at this visit to make sure the brace is properly applied before radiographs are obtained, to evaluate the in-brace film for possible improvements, and to address any complaints or problems raised by the patient.
After the brace-check visit, patients return for follow up every 6 months for an out-of-brace full spine radiograph, AP only unless a low radiation scanning radiography system like EOS is available, and a hand radiograph to evaluate skeletal maturity via Sanders staging. We ask our patients to be out of the brace for at least 24 hours prior to radiographs to minimize the persistent correction that can temporarily remain immediately after brace removal. Bracing is continued until skeletal maturity, which we define as Sanders grade 7 and less than 0.25-inch growth in a 6-month period. Although there is no evidence about the need to “wean” out of a brace, we recommend they transition from full-time to nighttime use for 6 months after which they can discontinue the brace. However, in practice, many patients feel uncomfortable when they stop wearing the brace cold turkey and continue wearing the brace at night well after we tell them they can stop.
After stopping the brace, we do a 6-month follow-up radiograph and then final radiograph 12 months after that to confirm stability of the curve. It is not unusual for there to be a little “progression” in the 6 months after bracing is stopped that may simply have been masked by the brace, and this nearly always stabilizes. For larger curves (>40 degrees, especially in the lumbar spine) and in curves that do not stabilize in the 18 months after bracing has been stopped, we will continue to observe.
Factors that modify the indications and prescription: There are some situations where we adjust the above protocol. Most studies have shown bracing to be less effective in very immature patients, those that are Risser grade 0, and especially with open triradiate cartilage. We address this in two ways depending on curve magnitude. For smaller curves (15–25 degrees), we have a protocol similar to Wiemann et al 22 who demonstrated that bracing at home for about 12 hours a day can prevent progression and avoid full-time bracing in about 25% of these patients. Most patients and families are very accepting of this protocol. We refer to this as “part-time” or “at-home” bracing as opposed to “nighttime” bracing as some children sleep as little as 6 to 7 hours at night, which is not likely an adequate duration. If the curve progresses, especially above 25 degrees, we then move to full-time bracing (16–18 h/d). For larger curves (>25 degrees) in the immature patients, especially those with still open triradiate cartilage, Weinstein et al 9 have demonstrated a 100% rate of progression, so we recommend 22 to 23 hours a day in the brace. We make sure to explain the reason for this aggressive prescription to the family, and we understand that likely few will be compliant.
PSSEs: We utilize PSSEs frequently and recommend that all of our brace patients at least try this technique. It is our experience that even a couple of sessions can improve brace compliance, and there is evidence suggesting that PSSEs can have an additive effect to bracing and the two techniques together may be more effective than bracing alone. 117 , 118 We also use this technique as a standalone intervention for patients with closed triradiate cartilage and curves in the 15- to 25-degree range to avoid progression and avoid the need for bracing.
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