n Feature Article
Effectiveness of Providence Nighttime Bracing in Patients With Adolescent Idiopathic Scoliosis Daniel D. Bohl, MPH; Connor J. Telles, MD; Nicholas S. Golinvaux, BA; Bryce A. Basques, BS; Peter A. DeLuca, MD; Jonathan N. Grauer, MD
abstract Full article available online at Healio.com/Orthopedics Interest has increased in adolescent idiopathic scoliosis braces that are worn only part time. One such brace, the Providence brace, is being used with increasing frequency despite limited literature evaluating its ability to alter the natural course of disease. The authors retrospectively identified 34 patients meeting modified Scoliosis Research Society (SRS) inclusion criteria who were treated with the Providence brace. In accordance with SRS criteria, patients were followed for progression more than 5°, progression to more than 45°, and recommendation for or performance of surgical fusion. Seventeen (50%) patients progressed more than 5°, and 9 (26%) progressed to more than 45° and had fusion surgery recommended or performed. Noncompliance was associated with progression to more than 45° (P=.045) and having fusion surgery recommended or performed (P=.045). Males had a higher rate of progression more than 5° than did females (100% vs 41%; P=.015). This is only the second study of the Providence brace to be guided by SRS criteria. The somewhat higher rates of progression more than 5° reported in these 2 studies compared with those reported in earlier studies likely result from this distinction. This study suggests a rate of progression that is similar to or lower than rates reported in natural history studies, possibly supporting the efficacy of the Providence brace. Additional studies using SRS criteria, including high-quality randomized, controlled trials, will be important to further understanding the relative effectiveness of this and other bracing protocols. [Orthopedics. 2014; 37(12):e1085-e1090.]
The authors are from the Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut. Mr Bohl, Dr Telles, Mr Golinvaux, Mr Basques, and Dr DeLuca have no relevant financial relationships to disclose. Dr Grauer is a paid consultant for Affinergy, Alphatec, Bioventus, DePuy, Stryker, Transgenomic, KCI, Medtronic, and Smith & Nephew. Correspondence should be addressed to: Jonathan N. Grauer, MD, Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, 800 Howard Ave, New Haven, CT 06510 (jonathan. [email protected]). Received: January 6, 2014; Accepted: March 25, 2014; Posted: December 10, 2014. doi: 10.3928/01477447-20141124-56
DECEMBER 2014 | Volume 37 • Number 12
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n Feature Article
B
racing is a mainstay of treatment for adolescent idiopathic scoliosis (AIS) mid-range curves. Although full-time bracing has the longest history, concern with compliance1,2 and negative psychosocial effects of daytime bracing3 have led to the study of part-time bracing protocols.4,5 Success with part-time protocols has been associated with more aggressive braces designed solely for nighttime use.6 These braces allow for greater in-brace curve corrections than standard thoracolumbosacral orthoses and are typically worn for 8 to 10 hours per day. Two wellknown designs are the Charleston brace and the Providence brace. The Charleston brace is a side-bending orthosis designed to hold the patient in an overcorrected position compared with traditional braces.7-13 The Providence brace, a more recent design, was introduced by d’Amato et al14 and uses controlled lateral and derotational forces on the trunk to move the spine toward or beyond the midline to gain curve correction.15,16 There has been a lack of uniformity among studies of bracing outcomes in defining inclusion criteria and standardizing outcomes.17 For example, as a greater understanding of the natural history of AIS developed, patients who were most at risk for curve progression were better identified, and those less at risk were excluded. Patients who were skeletally mature at initiation of bracing, those with curves so small that progression was unlikely, and those with curves so large that nonoperative treatment would be ineffective were more often excluded. The studies continued to lack a set of objective, standardized inclusion criteria. In addition, the outcomes measured by studies have varied greatly. Different studies have considered treatment a success only if curve progression does not exceed 5° at skeletal maturity, only if curve progression does not exceed 10° at skeletal maturity, only if the curve is less than 45° at skeletal maturity, or only if surgery was not necessary,
e1086
regardless of the amount of curve progression. This variation in inclusion criteria and outcomes makes it extremely difficult to compare the results of treatment across studies and brace types. As a result, in 2005, Richards et al,17 in conjunction with a committee of the Scoliosis Research Society (SRS), published a set of standard inclusion criteria and outcomes to be used in future bracing studies. To date, there are only 3 studies in the literature reporting the clinical outcomes of Providence bracing of AIS patients.14-16 Two of these studies were conducted prior to the publication of SRS criteria for standardization of bracing studies,14-15 whereas only 1 was conducted after and adheres to the criteria.16 The current study reports the authors’ experience with this nighttime bracing system compared with the published data on the natural history of AIS, the published data on other braces, and the limited clinical data on the Providence brace to date. Importantly, the study adheres to SRS criteria for standardization of bracing studies, with 2 modifications, as described here.
Materials and Methods The authors conducted a retrospective cohort study with the approval of the institutional review board. Through a review of medical records, the authors identified all patients treated with the Providence brace between 2003 and 2008 by a senior author (P.A.D.). Further inclusion criteria were based on the SRS criteria for standardization of bracing studies.17 These include an initial age of 10 years or older, initial Risser stage between 0 and 2, initial Cobb angle between 25° and 40°, no prior treatment, no secondary diagnosis, and, if female, either initially premenarchal or less than 1 year postmenarchal. Scoliosis Research Society criteria also require that patients without progression be followed until 2 years after skeletal maturity to ensure nonprogression. To accommodate the local practice of scoliosis bracing, the criteria were extended to include curves of
Table 1
Patient Demographics at Brace Initiation Demographic Variable Total
No. (%) of Patients 34 (100)
Age, y 10-11
8 (24)
12-13
18 (53)
14-15
8 (24)
Sex Female
29 (85)
Male
5 (15)
Initial Cobb angle 20°-24°
9 (26)
25°-29°
15 (44)
30°-40°
10 (29)
Curve subtype Thoracic
17 (50)
Thoracolumbar/ lumbar
9 (26)
Double
8 (24)
Apex T8 and cephalad
14 (41)
Caudal to T8
20 (49)
Risser stage 0
22 (65)
1
5 (15)
2
7 (21)
20° or greater that had been braced after observation of progression as well as a minimum follow-up of 1 year after brace discontinuation or skeletal maturity. Patients were instructed to wear the brace for a minimum of 8 hours while sleeping each night. As part of routine practice, at the first follow-up visit after bracing was prescribed, a posteroanterior prone radiograph was taken to calculate percent correction of the curve in the brace and to make adjustments to the brace as needed. At subsequent follow-up visits, standing posteroanterior radiographs out of the brace were taken to assess curve
ORTHOPEDICS | Healio.com/Orthopedics
n Feature Article
Table 2
Table 3
Providence Bracing Outcomes
Noncompliance With Bracing Instructions
Outcome
No. (%) of Patients
Progression >5° (primary outcome) No Yes
17 (50) 17 (50)
Progression to >45° No
25 (74)
Yes
9 (26)
Fusion surgery recommended or performed No
25 (74)
Yes
9 (26)
magnitude. Bracing was continued until skeletal maturity as determined by Risser stage 4 or higher, no axial growth over 2 visits 6 months apart, or at least 18 months postmenses. Patients were then followed at regular intervals after brace discontinuation to assess for any further curve progression. Demographic, clinical, and radiographic data were collected by review of patient charts and radiographs. Patient charts were reviewed for comments regarding noncompliance. Any patient who had a comment suggesting noncompliance in his or her chart was categorized as noncompliant; all other patients were categorized as compliant. Outcomes were as established by SRS criteria for standardization of bracing studies. The primary outcome was progression more than 5° at skeletal maturity. Secondary outcomes were progression to more than 45° at skeletal maturity and recommendation for or performance of surgical fusion. Data were analyzed using STATA version 11.2 statistical software (StataCorp, College Station, Texas). Statistical analyses were performed using Pearson’s chi-square test. Statistical difference was
DECEMBER 2014 | Volume 37 • Number 12
Outcome
Proportion (%) Noncompliant
All patients Progression >5°
.132
No
3/17 (18)
Yes
7/17 (42)
Progression to >45°
.045
No
5/25 (20)
Yes
5/9 (56)
Fusion surgery recommended or performed
.045
No
5/25 (20)
Yes
5/9 (56)
established at a 2-sided ß level of 0.05 (P5°
Table 5
Rates of Progression More Than 5° by Demographic Variable Demographic Variable
Proportion (%) Progressing More Than 5°
All patients Age, y
.256
10-11
5/8 (63)
12-13
10/18 (56)
14-15
2/8 (25)
Sex
.015
Female
12/29 (41)
Male
5/5 (100)
Initial Cobb angle
.315
20°-24°
5/9 (56)
25°-29°
9/15 (60)
30°-40°
3/10 (30)
Curve subtype
.459
Thoracic
9/17 (53)
Thoracolumbar/lumbar
3/9 (33)
Double
5/8 (63)
Apex
.163
T8 and cephalad
9/14 (64)
Caudal to T8
8/20 (40)
Risser stage
.105
0
13/22 (59)
1
3/5 (60)
2
1/7 (14)
pared with the rate of progression more than 5° of 68% observed by Lonstein and Carlson.18 Similarly, criteria for inclusion in the subset for comparison to Nachemson and Peterson19 were those of their own study plus female patients and a Cobb an-
e1088
P
17/34 (50)
gle of 25° to 35° at brace initiation. When they applied these additional inclusion criteria to the authors’ study population, that population fell to 22 patients, and the rate of progression more than 5° was 41%. This can be compared with the rate of pro-
Bracing is a mainstay of treatment for AIS, and in recent years, interest in braces designed to be worn only part time has increased.1-6 One such brace, the Providence brace, is being used with increasing frequency despite limited literature evaluating its ability to alter the natural course of disease. The current study is only the fourth14-16 to describe outcomes of bracing with the Providence brace and only the second16 to do so using SRS criteria for standardization of bracing studies.17 Overall, half of the patients in the current study progressed more than 5°, and approximately a quarter of the patients progressed to more than 45°, and that same quarter of patients had fusion surgery recommended or performed. This was accomplished with an average inbrace curve correction of 90%. Although noncompliance was not associated with progression more than 5°, it was associated with progression to more than 45° and having fusion surgery recommended or performed. And among demographic variables, progression more than 5° was more likely only with variable of male sex. The first studies to report outcomes of nighttime Providence bracing were conducted by d’Amato et al14 and Yrjonen et al.15 Both were prospective studies conducted before publication of SRS criteria.17 The studies had rates of progression more than 5° of 26% and 27%, respectively, which are somewhat lower than the current study’s rate of 50%. These rates were accomplished with average inbrace curve corrections of 96% and 92%, respectively, which are similar to the current study’s average correction of 90%. The difference between the reported rates of progression and the current study’s rate of progression most likely lies in the different inclusion criteria used by the earlier studies. Perhaps most importantly, the new SRS inclusion criteria require analyses to
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n Feature Article
be based on intent to treat. Whereas the current study conformed to this requirement, including noncompliant patients in the analysis, d’Amato et al14 and Yrjonen et al15 did not. The third study of outcomes of bracing with the Providence brace was conducted by Janicki et al.16 It was a retrospective study of 35 patients and used inclusion criteria similar to those used in the current study, including not excluding noncompliant patients. These authors reported a rate of progression more than 5° of 69%, somewhat higher than the rate of progression in the current study. Although the difference in rates of progression between these 2 studies may reflect real differences based on patient population or physician practice, given the similarly modest sample sizes of both studies, it is also possible that the difference is the result of random error. The outcomes of Providence bracing in these 4 studies can be compared with the more extensive literature on the outcomes of part-time bracing with the Charleston brace.7-13 These studies show rates of progression more than 5° ranging from 17% to 57%, which encompasses the current study’s rate of progression of 50%. This reported range of progression rates was achieved with a Charleston brace with average in-brace curve corrections from 70% to 87%, somewhat less than in the current study. Of note, none of these studies adhered to SRS criteria for standardization of bracing studies. The outcomes can also be compared with the literature on Boston bracing. Although the Boston brace is worn full time, it only achieves approximately 50% inbrace curve correction. Reported Boston bracing rates of progression more than 5° range from 18% to 69%,8,20-23 which includes the current study’s rate for the Providence brace. Only 1 of these studies adhered to modified SRS criteria.23 That study, the BRAIST randomized controlled trial, reported an intent-to-treat rate of bracing failure of 25% (defined by
DECEMBER 2014 | Volume 37 • Number 12
curve progression to 50° or more). Unfortunately, it did not report a specific rate of progression more than 5° and so cannot be directly compared with the current study. Finally, the current authors can compare outcomes of bracing studies with natural history data presented in earlier studies. Among patients with Risser stage between 0 and 1 and a curve magnitude between 20° and 29°, Lonstein and Carlson18 reported a 68% rate of progression more than 5°. When the current study is restricted to this same subset of patients (21 patients), the rate of progression is 67%. These 2 rates are similar, failing to provide evidence for the Providence brace’s efficacy. However, among females with curves between 25° and 35°, Nachemson and Peterson19 reported a 66% rate of progression more than 5°. When the current study is restricted to this same subset of patients (22 patients), the rate of progression is 41%, lower than that observed in natural history, supporting the Providence brace’s efficacy. In the current study, patients who progressed to more than 45° had a higher rate of noncompliance compared with patients who did not progress to more than 45°. Compliance has been shown to correlate with brace success, and methods have been designed to objectively measure brace compliance.1,2,22 Many studies cite the potential of part-time braces to improve compliance rates and therefore improve success rates. However, compliance rates have not been objectively monitored in any of the nighttime brace studies to date (including the current study). Some of these studies neglect to report compliance—subjective or otherwise—altogether. This is an area for future research. Limitations of the current study include its retrospective nature, lack of randomization, and lack of a control group. Also, there was only a subjective assessment of compliance, relying on patient or caregiver reporting in clinic notes rather than on more objective means. Expectancy bias or confirmation bias could have
led to disproportionate documentation of noncompliance by the senior author; that is, there could have been a natural cognitive bias in the setting of failed brace wear/progression to surgery, leading to increased documentation of noncompliance in these cases. Finally, the authors had a substantial number of initially identified patients who had insufficient follow-up and had to be excluded from the analysis.
Conclusion This study is only the second study of outcomes of Providence bracing to be based on SRS criteria for standardization of bracing studies. The somewhat higher rates of progression more than 5° reported in these 2 studies compared with those reported in earlier studies likely result from this distinction. This study suggests a rate of progression that is similar to or lower than rates reported in natural history studies, possibly supporting the efficacy of the Providence brace. Additional studies using SRS criteria, including high-quality randomized, controlled trials, will be important to further understanding the relative effectiveness of this and other bracing protocols. In particular, future prospective studies should include an objective assessment of compliance using a validated method such as a temperature sensor, which allows calculation of a dose response, where the dose is hours worn per day.1,2,22 In addition to simple measures of compliance, attention to the psychosocial effect of nighttime vs full-time bracing as a secondary outcome of a prospective trial would also be useful to clinicians. The methods used in the BRAIST randomized, controlled trial of the Boston brace23 are now the gold standard for bracing trials. Those authors enrolled both a randomized cohort and a preference cohort, and their conclusions were based both on as-treated (with propensity score adjustment) and intent-to-treat analyses. These dual analyses, along with the demonstration of a convincing dose-response curve, give their study great strength and con-
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vincingly make the case for bracing using the Boston brace. A study with a similar approach to test for noninferiority of the Providence brace to the Boston brace, or the superiority of the Providence brace to no treatment, would be useful to clinicians.
References 1. Rahman T, Bowen JR, Takemitsu M, Scott C. The association between brace compliance and outcome for patients with idiopathic scoliosis. J Pediatr Orthop. 2005; 25(4):420422. 2. Helfenstein A, Lankes M, Ohlert K, et al. The objective determination of compliance in treatment of adolescent idiopathic scoliosis with spinal orthoses. Spine (Phila Pa 1976). 2006; 31(3):339-344. 3. Climent JM, Sanchez J. Impact of the type of brace on the quality of life of adolescents with spine deformities. Spine (Phila Pa 1976). 1999; 24(18):1903-1908. 4. Allington NJ, Bowen JR. Adolescent idiopathic scoliosis: treatment with the Wilmington brace: a comparison of full-time and part-time use. J Bone Joint Surg Am. 1996; 78(7):1056-1062. 5. Green NE. Part-time bracing of adolescent idiopathic scoliosis. J Bone Joint Surg Am. 1986; 68(5):738-742. 6. Grivas TB, Rodopoulos GI, Bardakos NV. Night-time braces for treatment of adolescent idiopathic scoliosis. Disabil Rehabil Assist Technol. 2008; 3(3):120-129. 7. Price CT, Scott DS, Reed FE Jr, Riddick MF. Nighttime bracing for adolescent idiopathic
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scoliosis with the Charleston bending brace: preliminary report. Spine (Phila Pa 1976). 1990; 15(12):1294-1299. 8. Katz DE, Richards BS, Browne RH, Herring JA. A comparison between the Boston brace and the Charleston bending brace in adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 1997; 22(12):1302-1312. 9. Price CT, Scott DS, Reed FR Jr, Sproul JT, Riddick MF. Nighttime bracing for adolescent idiopathic scoliosis with the Charleston Bending Brace: long-term follow-up. J Pediatr Orthop. 1997; 17(6):703-707. 10. Howard A, Wright JG, Hedden D. A comparative study of TLSO, Charleston, and Milwaukee braces for idiopathic scoliosis. Spine (Phila Pa 1976). 1998; 23(22):2404-2411. 11. Bowen JR, Keeler KA, Pelegie S. Adolescent idiopathic scoliosis managed by a nighttime bending brace. Orthopedics. 2001; 24(10):967-970. 12. Trivedi JM, Thomson JD. Results of Charleston bracing in skeletally immature patients with idiopathic scoliosis. J Pediatr Orthop. 2001; 21(3):277-280. 13. Gepstein R, Leitner Y, Zohar E, et al. Effectiveness of the Charleston bending brace in the treatment of single-curve idiopathic scoliosis. J Pediatr Orthop. 2002; 22(1):84-87. 14. D’Amato CR, Griggs S, McCoy B. Nighttime bracing with the Providence brace in adolescent girls with idiopathic scoliosis. Spine (Phila Pa 1976). 2001; 26(18):2006-2012. 15. Yrjonen T, Ylikoski M, Schlenzka D, Kinnunen R, Poussa M. Effectiveness of the Providence nighttime bracing in adolescent idiopathic scoliosis: a comparative study of 36 female patients. Eur Spine J. 2006; 15(7):1139-1143. 16. Janicki JA, Poe-Kochert C, Armstrong DG,
Thompson GH. A comparison of the thoracolumbosacral orthoses and providence orthosis in the treatment of adolescent idiopathic scoliosis: results using the new SRS inclusion and assessment criteria for bracing studies. J Pediatr Orthop. 2007; 27(4):369-374. 17. Richards BS, Bernstein RM, D’Amato CR, Thompson GH. Standardization of criteria for adolescent idiopathic scoliosis brace studies: SRS Committee on Bracing and Nonoperative Management. Spine (Phila Pa 1976). 2005; 30(18):2068-2075. 18. Lonstein JE, Carlson JM. The prediction of curve progression in untreated idiopathic scoliosis during growth. J Bone Joint Surg Am. 1984; 66(7):1061-1071. 19. Nachemson AL, Peterson LE. Effectiveness of treatment with a brace in girls who have adolescent idiopathic scoliosis: a prospective, controlled study based on data from the Brace Study of the Scoliosis Research Society. J Bone Joint Surg Am. 1995; 77(6):815822. 20. Katz DE, Durrani AA. Factors that influence outcome in bracing large curves in patients with adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2001; 26(21):2354-2361. 21. Ganjavian MS, Behtash H, Ameri E, Khakinahad M. Results of Milwaukee and Boston braces with or without metal marker around pads in patients with idiopathic scoliosis. Acta Med Iran. 2011; 49(9):598-605. 22. Katz DE, Herring JA, Browne RH, Kelly DM, Birch JG. Brace wear control of curve progression in adolescent idiopathic scoliosis. J Bone Joint Surg Am. 2010; 92(6):13431352. 23. Weinstein SL, Dolan LA, Wright JG, Dobbs MB. Effects of bracing in adolescents with idiopathic scoliosis. N Engl J Med. 2013; 369(16):1512-1521.
ORTHOPEDICS | Healio.com/Orthopedics
Effectiveness of Providence Nighttime Bracing in Patients With Adolescent Idiopathic Scoliosis Daniel D. Bohl, MPH; Connor J. Telles, MD; Nicholas S. Golinvaux, BA; Bryce A. Basques, BS; Peter A. DeLuca, MD; Jonathan N. Grauer, MD
abstract Full article available online at Healio.com/Orthopedics Interest has increased in adolescent idiopathic scoliosis braces that are worn only part time. One such brace, the Providence brace, is being used with increasing frequency despite limited literature evaluating its ability to alter the natural course of disease. The authors retrospectively identified 34 patients meeting modified Scoliosis Research Society (SRS) inclusion criteria who were treated with the Providence brace. In accordance with SRS criteria, patients were followed for progression more than 5°, progression to more than 45°, and recommendation for or performance of surgical fusion. Seventeen (50%) patients progressed more than 5°, and 9 (26%) progressed to more than 45° and had fusion surgery recommended or performed. Noncompliance was associated with progression to more than 45° (P=.045) and having fusion surgery recommended or performed (P=.045). Males had a higher rate of progression more than 5° than did females (100% vs 41%; P=.015). This is only the second study of the Providence brace to be guided by SRS criteria. The somewhat higher rates of progression more than 5° reported in these 2 studies compared with those reported in earlier studies likely result from this distinction. This study suggests a rate of progression that is similar to or lower than rates reported in natural history studies, possibly supporting the efficacy of the Providence brace. Additional studies using SRS criteria, including high-quality randomized, controlled trials, will be important to further understanding the relative effectiveness of this and other bracing protocols. [Orthopedics. 2014; 37(12):e1085-e1090.]
The authors are from the Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut. Mr Bohl, Dr Telles, Mr Golinvaux, Mr Basques, and Dr DeLuca have no relevant financial relationships to disclose. Dr Grauer is a paid consultant for Affinergy, Alphatec, Bioventus, DePuy, Stryker, Transgenomic, KCI, Medtronic, and Smith & Nephew. Correspondence should be addressed to: Jonathan N. Grauer, MD, Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, 800 Howard Ave, New Haven, CT 06510 (jonathan. [email protected]). Received: January 6, 2014; Accepted: March 25, 2014; Posted: December 10, 2014. doi: 10.3928/01477447-20141124-56
DECEMBER 2014 | Volume 37 • Number 12
e1085
n Feature Article
B
racing is a mainstay of treatment for adolescent idiopathic scoliosis (AIS) mid-range curves. Although full-time bracing has the longest history, concern with compliance1,2 and negative psychosocial effects of daytime bracing3 have led to the study of part-time bracing protocols.4,5 Success with part-time protocols has been associated with more aggressive braces designed solely for nighttime use.6 These braces allow for greater in-brace curve corrections than standard thoracolumbosacral orthoses and are typically worn for 8 to 10 hours per day. Two wellknown designs are the Charleston brace and the Providence brace. The Charleston brace is a side-bending orthosis designed to hold the patient in an overcorrected position compared with traditional braces.7-13 The Providence brace, a more recent design, was introduced by d’Amato et al14 and uses controlled lateral and derotational forces on the trunk to move the spine toward or beyond the midline to gain curve correction.15,16 There has been a lack of uniformity among studies of bracing outcomes in defining inclusion criteria and standardizing outcomes.17 For example, as a greater understanding of the natural history of AIS developed, patients who were most at risk for curve progression were better identified, and those less at risk were excluded. Patients who were skeletally mature at initiation of bracing, those with curves so small that progression was unlikely, and those with curves so large that nonoperative treatment would be ineffective were more often excluded. The studies continued to lack a set of objective, standardized inclusion criteria. In addition, the outcomes measured by studies have varied greatly. Different studies have considered treatment a success only if curve progression does not exceed 5° at skeletal maturity, only if curve progression does not exceed 10° at skeletal maturity, only if the curve is less than 45° at skeletal maturity, or only if surgery was not necessary,
e1086
regardless of the amount of curve progression. This variation in inclusion criteria and outcomes makes it extremely difficult to compare the results of treatment across studies and brace types. As a result, in 2005, Richards et al,17 in conjunction with a committee of the Scoliosis Research Society (SRS), published a set of standard inclusion criteria and outcomes to be used in future bracing studies. To date, there are only 3 studies in the literature reporting the clinical outcomes of Providence bracing of AIS patients.14-16 Two of these studies were conducted prior to the publication of SRS criteria for standardization of bracing studies,14-15 whereas only 1 was conducted after and adheres to the criteria.16 The current study reports the authors’ experience with this nighttime bracing system compared with the published data on the natural history of AIS, the published data on other braces, and the limited clinical data on the Providence brace to date. Importantly, the study adheres to SRS criteria for standardization of bracing studies, with 2 modifications, as described here.
Materials and Methods The authors conducted a retrospective cohort study with the approval of the institutional review board. Through a review of medical records, the authors identified all patients treated with the Providence brace between 2003 and 2008 by a senior author (P.A.D.). Further inclusion criteria were based on the SRS criteria for standardization of bracing studies.17 These include an initial age of 10 years or older, initial Risser stage between 0 and 2, initial Cobb angle between 25° and 40°, no prior treatment, no secondary diagnosis, and, if female, either initially premenarchal or less than 1 year postmenarchal. Scoliosis Research Society criteria also require that patients without progression be followed until 2 years after skeletal maturity to ensure nonprogression. To accommodate the local practice of scoliosis bracing, the criteria were extended to include curves of
Table 1
Patient Demographics at Brace Initiation Demographic Variable Total
No. (%) of Patients 34 (100)
Age, y 10-11
8 (24)
12-13
18 (53)
14-15
8 (24)
Sex Female
29 (85)
Male
5 (15)
Initial Cobb angle 20°-24°
9 (26)
25°-29°
15 (44)
30°-40°
10 (29)
Curve subtype Thoracic
17 (50)
Thoracolumbar/ lumbar
9 (26)
Double
8 (24)
Apex T8 and cephalad
14 (41)
Caudal to T8
20 (49)
Risser stage 0
22 (65)
1
5 (15)
2
7 (21)
20° or greater that had been braced after observation of progression as well as a minimum follow-up of 1 year after brace discontinuation or skeletal maturity. Patients were instructed to wear the brace for a minimum of 8 hours while sleeping each night. As part of routine practice, at the first follow-up visit after bracing was prescribed, a posteroanterior prone radiograph was taken to calculate percent correction of the curve in the brace and to make adjustments to the brace as needed. At subsequent follow-up visits, standing posteroanterior radiographs out of the brace were taken to assess curve
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Table 2
Table 3
Providence Bracing Outcomes
Noncompliance With Bracing Instructions
Outcome
No. (%) of Patients
Progression >5° (primary outcome) No Yes
17 (50) 17 (50)
Progression to >45° No
25 (74)
Yes
9 (26)
Fusion surgery recommended or performed No
25 (74)
Yes
9 (26)
magnitude. Bracing was continued until skeletal maturity as determined by Risser stage 4 or higher, no axial growth over 2 visits 6 months apart, or at least 18 months postmenses. Patients were then followed at regular intervals after brace discontinuation to assess for any further curve progression. Demographic, clinical, and radiographic data were collected by review of patient charts and radiographs. Patient charts were reviewed for comments regarding noncompliance. Any patient who had a comment suggesting noncompliance in his or her chart was categorized as noncompliant; all other patients were categorized as compliant. Outcomes were as established by SRS criteria for standardization of bracing studies. The primary outcome was progression more than 5° at skeletal maturity. Secondary outcomes were progression to more than 45° at skeletal maturity and recommendation for or performance of surgical fusion. Data were analyzed using STATA version 11.2 statistical software (StataCorp, College Station, Texas). Statistical analyses were performed using Pearson’s chi-square test. Statistical difference was
DECEMBER 2014 | Volume 37 • Number 12
Outcome
Proportion (%) Noncompliant
All patients Progression >5°
.132
No
3/17 (18)
Yes
7/17 (42)
Progression to >45°
.045
No
5/25 (20)
Yes
5/9 (56)
Fusion surgery recommended or performed
.045
No
5/25 (20)
Yes
5/9 (56)
established at a 2-sided ß level of 0.05 (P5°
Table 5
Rates of Progression More Than 5° by Demographic Variable Demographic Variable
Proportion (%) Progressing More Than 5°
All patients Age, y
.256
10-11
5/8 (63)
12-13
10/18 (56)
14-15
2/8 (25)
Sex
.015
Female
12/29 (41)
Male
5/5 (100)
Initial Cobb angle
.315
20°-24°
5/9 (56)
25°-29°
9/15 (60)
30°-40°
3/10 (30)
Curve subtype
.459
Thoracic
9/17 (53)
Thoracolumbar/lumbar
3/9 (33)
Double
5/8 (63)
Apex
.163
T8 and cephalad
9/14 (64)
Caudal to T8
8/20 (40)
Risser stage
.105
0
13/22 (59)
1
3/5 (60)
2
1/7 (14)
pared with the rate of progression more than 5° of 68% observed by Lonstein and Carlson.18 Similarly, criteria for inclusion in the subset for comparison to Nachemson and Peterson19 were those of their own study plus female patients and a Cobb an-
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gle of 25° to 35° at brace initiation. When they applied these additional inclusion criteria to the authors’ study population, that population fell to 22 patients, and the rate of progression more than 5° was 41%. This can be compared with the rate of pro-
Bracing is a mainstay of treatment for AIS, and in recent years, interest in braces designed to be worn only part time has increased.1-6 One such brace, the Providence brace, is being used with increasing frequency despite limited literature evaluating its ability to alter the natural course of disease. The current study is only the fourth14-16 to describe outcomes of bracing with the Providence brace and only the second16 to do so using SRS criteria for standardization of bracing studies.17 Overall, half of the patients in the current study progressed more than 5°, and approximately a quarter of the patients progressed to more than 45°, and that same quarter of patients had fusion surgery recommended or performed. This was accomplished with an average inbrace curve correction of 90%. Although noncompliance was not associated with progression more than 5°, it was associated with progression to more than 45° and having fusion surgery recommended or performed. And among demographic variables, progression more than 5° was more likely only with variable of male sex. The first studies to report outcomes of nighttime Providence bracing were conducted by d’Amato et al14 and Yrjonen et al.15 Both were prospective studies conducted before publication of SRS criteria.17 The studies had rates of progression more than 5° of 26% and 27%, respectively, which are somewhat lower than the current study’s rate of 50%. These rates were accomplished with average inbrace curve corrections of 96% and 92%, respectively, which are similar to the current study’s average correction of 90%. The difference between the reported rates of progression and the current study’s rate of progression most likely lies in the different inclusion criteria used by the earlier studies. Perhaps most importantly, the new SRS inclusion criteria require analyses to
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be based on intent to treat. Whereas the current study conformed to this requirement, including noncompliant patients in the analysis, d’Amato et al14 and Yrjonen et al15 did not. The third study of outcomes of bracing with the Providence brace was conducted by Janicki et al.16 It was a retrospective study of 35 patients and used inclusion criteria similar to those used in the current study, including not excluding noncompliant patients. These authors reported a rate of progression more than 5° of 69%, somewhat higher than the rate of progression in the current study. Although the difference in rates of progression between these 2 studies may reflect real differences based on patient population or physician practice, given the similarly modest sample sizes of both studies, it is also possible that the difference is the result of random error. The outcomes of Providence bracing in these 4 studies can be compared with the more extensive literature on the outcomes of part-time bracing with the Charleston brace.7-13 These studies show rates of progression more than 5° ranging from 17% to 57%, which encompasses the current study’s rate of progression of 50%. This reported range of progression rates was achieved with a Charleston brace with average in-brace curve corrections from 70% to 87%, somewhat less than in the current study. Of note, none of these studies adhered to SRS criteria for standardization of bracing studies. The outcomes can also be compared with the literature on Boston bracing. Although the Boston brace is worn full time, it only achieves approximately 50% inbrace curve correction. Reported Boston bracing rates of progression more than 5° range from 18% to 69%,8,20-23 which includes the current study’s rate for the Providence brace. Only 1 of these studies adhered to modified SRS criteria.23 That study, the BRAIST randomized controlled trial, reported an intent-to-treat rate of bracing failure of 25% (defined by
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curve progression to 50° or more). Unfortunately, it did not report a specific rate of progression more than 5° and so cannot be directly compared with the current study. Finally, the current authors can compare outcomes of bracing studies with natural history data presented in earlier studies. Among patients with Risser stage between 0 and 1 and a curve magnitude between 20° and 29°, Lonstein and Carlson18 reported a 68% rate of progression more than 5°. When the current study is restricted to this same subset of patients (21 patients), the rate of progression is 67%. These 2 rates are similar, failing to provide evidence for the Providence brace’s efficacy. However, among females with curves between 25° and 35°, Nachemson and Peterson19 reported a 66% rate of progression more than 5°. When the current study is restricted to this same subset of patients (22 patients), the rate of progression is 41%, lower than that observed in natural history, supporting the Providence brace’s efficacy. In the current study, patients who progressed to more than 45° had a higher rate of noncompliance compared with patients who did not progress to more than 45°. Compliance has been shown to correlate with brace success, and methods have been designed to objectively measure brace compliance.1,2,22 Many studies cite the potential of part-time braces to improve compliance rates and therefore improve success rates. However, compliance rates have not been objectively monitored in any of the nighttime brace studies to date (including the current study). Some of these studies neglect to report compliance—subjective or otherwise—altogether. This is an area for future research. Limitations of the current study include its retrospective nature, lack of randomization, and lack of a control group. Also, there was only a subjective assessment of compliance, relying on patient or caregiver reporting in clinic notes rather than on more objective means. Expectancy bias or confirmation bias could have
led to disproportionate documentation of noncompliance by the senior author; that is, there could have been a natural cognitive bias in the setting of failed brace wear/progression to surgery, leading to increased documentation of noncompliance in these cases. Finally, the authors had a substantial number of initially identified patients who had insufficient follow-up and had to be excluded from the analysis.
Conclusion This study is only the second study of outcomes of Providence bracing to be based on SRS criteria for standardization of bracing studies. The somewhat higher rates of progression more than 5° reported in these 2 studies compared with those reported in earlier studies likely result from this distinction. This study suggests a rate of progression that is similar to or lower than rates reported in natural history studies, possibly supporting the efficacy of the Providence brace. Additional studies using SRS criteria, including high-quality randomized, controlled trials, will be important to further understanding the relative effectiveness of this and other bracing protocols. In particular, future prospective studies should include an objective assessment of compliance using a validated method such as a temperature sensor, which allows calculation of a dose response, where the dose is hours worn per day.1,2,22 In addition to simple measures of compliance, attention to the psychosocial effect of nighttime vs full-time bracing as a secondary outcome of a prospective trial would also be useful to clinicians. The methods used in the BRAIST randomized, controlled trial of the Boston brace23 are now the gold standard for bracing trials. Those authors enrolled both a randomized cohort and a preference cohort, and their conclusions were based both on as-treated (with propensity score adjustment) and intent-to-treat analyses. These dual analyses, along with the demonstration of a convincing dose-response curve, give their study great strength and con-
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vincingly make the case for bracing using the Boston brace. A study with a similar approach to test for noninferiority of the Providence brace to the Boston brace, or the superiority of the Providence brace to no treatment, would be useful to clinicians.
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scoliosis with the Charleston bending brace: preliminary report. Spine (Phila Pa 1976). 1990; 15(12):1294-1299. 8. Katz DE, Richards BS, Browne RH, Herring JA. A comparison between the Boston brace and the Charleston bending brace in adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 1997; 22(12):1302-1312. 9. Price CT, Scott DS, Reed FR Jr, Sproul JT, Riddick MF. Nighttime bracing for adolescent idiopathic scoliosis with the Charleston Bending Brace: long-term follow-up. J Pediatr Orthop. 1997; 17(6):703-707. 10. Howard A, Wright JG, Hedden D. A comparative study of TLSO, Charleston, and Milwaukee braces for idiopathic scoliosis. Spine (Phila Pa 1976). 1998; 23(22):2404-2411. 11. Bowen JR, Keeler KA, Pelegie S. Adolescent idiopathic scoliosis managed by a nighttime bending brace. Orthopedics. 2001; 24(10):967-970. 12. Trivedi JM, Thomson JD. Results of Charleston bracing in skeletally immature patients with idiopathic scoliosis. J Pediatr Orthop. 2001; 21(3):277-280. 13. Gepstein R, Leitner Y, Zohar E, et al. Effectiveness of the Charleston bending brace in the treatment of single-curve idiopathic scoliosis. J Pediatr Orthop. 2002; 22(1):84-87. 14. D’Amato CR, Griggs S, McCoy B. Nighttime bracing with the Providence brace in adolescent girls with idiopathic scoliosis. Spine (Phila Pa 1976). 2001; 26(18):2006-2012. 15. Yrjonen T, Ylikoski M, Schlenzka D, Kinnunen R, Poussa M. Effectiveness of the Providence nighttime bracing in adolescent idiopathic scoliosis: a comparative study of 36 female patients. Eur Spine J. 2006; 15(7):1139-1143. 16. Janicki JA, Poe-Kochert C, Armstrong DG,
Thompson GH. A comparison of the thoracolumbosacral orthoses and providence orthosis in the treatment of adolescent idiopathic scoliosis: results using the new SRS inclusion and assessment criteria for bracing studies. J Pediatr Orthop. 2007; 27(4):369-374. 17. Richards BS, Bernstein RM, D’Amato CR, Thompson GH. Standardization of criteria for adolescent idiopathic scoliosis brace studies: SRS Committee on Bracing and Nonoperative Management. Spine (Phila Pa 1976). 2005; 30(18):2068-2075. 18. Lonstein JE, Carlson JM. The prediction of curve progression in untreated idiopathic scoliosis during growth. J Bone Joint Surg Am. 1984; 66(7):1061-1071. 19. Nachemson AL, Peterson LE. Effectiveness of treatment with a brace in girls who have adolescent idiopathic scoliosis: a prospective, controlled study based on data from the Brace Study of the Scoliosis Research Society. J Bone Joint Surg Am. 1995; 77(6):815822. 20. Katz DE, Durrani AA. Factors that influence outcome in bracing large curves in patients with adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2001; 26(21):2354-2361. 21. Ganjavian MS, Behtash H, Ameri E, Khakinahad M. Results of Milwaukee and Boston braces with or without metal marker around pads in patients with idiopathic scoliosis. Acta Med Iran. 2011; 49(9):598-605. 22. Katz DE, Herring JA, Browne RH, Kelly DM, Birch JG. Brace wear control of curve progression in adolescent idiopathic scoliosis. J Bone Joint Surg Am. 2010; 92(6):13431352. 23. Weinstein SL, Dolan LA, Wright JG, Dobbs MB. Effects of bracing in adolescents with idiopathic scoliosis. N Engl J Med. 2013; 369(16):1512-1521.
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