**4. Discussion**

Symmetrical braces (Boston style with dorsal or ventral closures) provide success rates of 70% or little over [7, 9, 32–35] (**Figure 2**). Asymmetrical threedimensional braces (mainly Chêneau style) may have success rates between less than 50 and more than 90% [8, 36–49]. There is a wide variety of outcomes used in research, which may be related to the differing qualities of asymmetrical brace adjustments and designs (**Figures 3**–**5**).

With a more or less symmetrical tube shape (**Figure 2**) brace construction is more simple, whilst asymmetrical braces can only be constructed and adjusted well

### **Figure 2.**

*Visually almost symmetrical braces mainly correcting via trunk compression. (a) Boston brace made with a little shift towards the thoracic concavity, (b) Boston brace from Denmark pushing the trunk into the main thoracic curve and (c and d) symmetrical compression braces from Italy [34, 35].*

### **Figure 3.**

*Different Chêneau style braces all for a main thoracic curve to the right. (a) Rigo brace and (b) Gensingen (GBW) brace clearly mirroring the deformity shifting the thoracic part of the trunk to the left. (c and d) Hand-made Chêneau derivatives without obvious impact on the trunk deformity still decompensated to the right in the brace. In a good asymmetrical high correction brace mirroring of the deformity will always be visible (a and b).*

### **Figure 4.**

*Asymmetrical high correction brace (GBW) with a clear mirroring of the deformity in the brace and a reasonably successful cosmetic improvement along with the in-brace correction as shown on the right. GBW brace produced in May, 2019 with a thoracic curvature of 45°, lumbar curvature of 24°. In-brace X-ray, thoracic 7°, lumbar 7° Cobb (courtesy of Xiaofeng Nan, Xi'an, China).*

with a very experienced and highly skilled technician/orthotist or by using well calibrated and reliable CAD (computer-aided design, see **Figures 3**–**5**) series based on certain classifications and proven reliable methods [76, 77].

It is not the name of the brace that ensures a good outcome; it is the brace manufacture and adjustments based on standardised algorithms [76, 77]. It is concerning that in many studies on brace treatment, an example of the brace design is not presented in a picture [55, 78]; sometimes the brace design is not even named [78].

*Brace Treatment for Children and Adolescents with Scoliosis DOI: http://dx.doi.org/10.5772/intechopen.91234*

### **Figure 5.**

*Girl with a Risser stage of IV. The thoracic curve initially was 34° and the lumbar 20°. After wearing the GBW brace in-brace X-ray of the thoracic curve was 11° and lumbar 14°. Half a year later X-ray without the brace (for over 24 hours) is 24° and lumbar 20° with a reasonable clinical correction as seen on the right. This case shows that also in the more mature patient significant cosmetic improvements can be gained (courtesy of Xiaofeng Nan, Xi'an, China).*

### **Figure 6.**

*X-ray of a patient with a main thoracic curve to the right (a). (b) No correction in a Boston style brace and (c) reasonable correction of the curve in a GBW, after the patient changed her brace due to discomfort in the Boston brace (courtesy of Dr Marc Moramarco, Scoliosis 3DC, Woburn, MA, US).*

Outcomes with respect to Cobb angle: Landauer et al. in their retrospective study [37] examined 62 adolescent female patients with right thoracic scoliosis (20–40 Cobb degrees) treated with a Chêneau style brace. Initial correction improvements of >40% (p < 0.002) and satisfactory compliance (p < 0.004) gained a significantly successful outcome (**Figure 6**). There was an average improvement of 7° in Cobb angle, with patients with good compliance and with a significant initial correction.

The authors concluded that compliant patients with a high initial correction can expect a final correction of around 7°, whilst compliant patients with low initial correction may maintain the curve to some extent. Bad compliance was associated with curve progression.

Bullmann and colleagues in their study [38] had 52 patients with a Cobb angle of between 25 and 40°. Prior to starting brace treatment with the Chêneau-Toulouse-Muenster orthosis, skeletal age and flexibility of the curve (bending films) were evaluated. The average follow-up after weaning of the brace was 42 months (36–78 months). Three years after weaning there was an overall increase of the Cobb angle to 37° on average. The authors concluded that curve progression was prevented in 58%. Prognostic risk factors were a young age at the start of brace treatment, a thoracic curve, unsatisfactory curve correction in the brace and a male gender.

Zaborowska-Sapeta et al. presented a prospective study using SRS and SOSORT guidelines [40], including 79 progressive idiopathic patients (58 girls and 21 boys). The treatment included a Chêneau brace and physiotherapy. And the patient group included an initial Cobb angle between 20 and 45°, Risser 4 maturity at final assessment and no other or previous brace treatment. The follow up results were outlined that 25.3% improved, 22.8% were stable with no change in progression, 39.2% worsened and progressed but below the surgical indicated level of 50° Cobb angle and 12.7% worsened and progressed beyond 50°. Two patients out of the initial 79 patients progressed >60° Cobb angles. Progression concerned the younger and less skeletally mature patients. The results of this study may indicate that this Chêneau style and design of the brace used is more effective in reducing the incidence of surgery, even when it is compared to the natural history (without treatment) of this condition.

These are two studies with low quality Chêneau style braces. Both studies indicate that less skeletally mature patients had worse outcomes than the more mature patients. This seems the typical finding in low quality braces that patients more at risk for progression have worse outcomes than the more mature lower-risk patients [55, 70].

In studies with more high quality brace designs, the more immature patients seem easier to correct and preserve better outcomes than the more mature patients [45, 47, 74, 75, 79, 82].

Aulisa and colleagues reviewed 93 patients with adolescent idiopathic scoliosis (AIS) that implemented the PASB (Progressive Action Short Brace) and the Lyon method [46]. The age range was wide, ages from 10 to 35 years old. Two groups were separated according to their Cobb, less than30° and more than30°. The follow-up was long, at a mean age of 184.1 months (±72.60) after treatment was stopped. The pre-treatment mean Cobb angle was 32.28° (±9.4°), the post treatment mean was 19.35° and then increased to 22.12° in the 10 years after the end of treatment. No significant change was noted in the mean Cobb angle between the end of weaning and the later follow up (p = 0.105). Patients prescribed a brace from the beginning had reduced Cobb angles by 13° within the treatment period, which then worsened by 3° after treatment ended. The group with Cobb angles >30° showed a pre-brace mean curve of 41.15°; then at the end of treatment, the mean angle was 25.85° and had worsened with a mean of 29.73° at later follow-up. The group with ≤30° Cobb angle initially presented with a mean Cobb angle of 25.58° which then reduced to a mean of 14.24°, but then worsened after treatment to 16.38°. There was no significant change in the mean progression of Cobb angles between the two groups. This paper concluded that scoliosis did not progress in 15 years after treatment. The natural history of this pathology, at these levels of moderate severity, deems that normally a progressive but small increment will continue to worsen

until skeletal maturity. High-quality bracing is a valuable and effective alternative treatment method, demonstrated by successful long-term follow-up outcomes, even with patients that initially present with moderate AIS.

In another paper with curves initially presenting at 40° and which included over fifty-five participants [47]. Just under half of the participants had a minimum follow-up of 18 months and an average of 30.4 months (SD 9.2).

The 25 patients had the following characteristics at their initial presentation: Cobb angle of 49° (SD 8.4; 40–71°); 12.4 years old (SD 0.82); Risser: 0.84 (SD 0.94; 0–2). A statistical z-test was used to compare the success rate in this cohort to the success rate in the prospective braced cohort from BrAIST (Bracing in Adolescent Idiopathic Scoliosis Trial).

At follow-up, the average Cobb angle was 44.2° (SD 12.9). Two patients progressed, 12 patients were able to halt progression, and 11 patients improved. Angle of trunk rotation (ATR), demonstrating cosmetic improvements, decreased from over 12° to just over 10° in the thoracic spine (p = 0.11) and from 4.7 to 3.6° ATR improvements noted in the lumbar spine (p = 0.0074). When comparing the success rate to the BrAIST cohort with the success rate of patients in this cohort, the difference was statistically significant (z = −3.041; p = 0.01). The Gensingen brace was successful in 92% of cases of patients with AIS, whose patient group initially presented with large curvatures and the improvements were significantly more effective when compared to the BrAIST study results of 72%, whose patient group initially had smaller curves comparatively.

Recently, a paper was published with the SRS inclusion criteria for studies on bracing (Girls only, Age 10–14 years, Risser 0–2, Cobb angle 25–40°), the range of Cobb angles was extended to curvatures of up to 45° in order to increase the amount of participants in the study [79]. Twenty-eight patients from their prospective cohort (12.5 years; Risser 0.8; Cobb 32.6°) were weaned off their CAD Chêneau style brace (Gensingen brace). The results of this cohort were compared with the BrAIST study by Weinstein et al. with the help of the z-test. Failure in both studies was defined as a Cobb angle reaching or exceeding 50° Cobb.

The in-brace correction was 51.4%. Two out of the 28 patients (7.1%) from this group reached or exceeded 50° Cobb angle at final follow-up making a success rate 92.9%. Comparative to the results of 72% in the BrAIST study, the improvement was highly significant in the z-test (z = 2.58, t = −3,42, p = 0.01).

The authors concluded that the results as achieved with the Gensingen brace were significantly better than the results as achieved with the Boston brace. Therefore, the standards should be adapted from symmetrical compression braces to asymmetrical high correction braces, maintaining improved standards by use of a classification-based corrective system for most of the possible curve patterns.

These results show the high variability of outcomes with different asymmetrical braces with very different qualities. Low quality asymmetrical braces seem to have outcomes with insignificant effects to natural history, and high-quality asymmetrical braces offer the advantage of improving Cobb angle and the cosmetic and postural issues of the deformity [45–47, 74, 75, 79–82].
