Braces for idiopathic scoliosis in adolescents
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
The primary aim of this review is to evaluate the efficacy of bracing for adolescents with idiopathic scoliosis versus no treatment or other treatments, on quality of life, disability, pulmonary disorders, progression of the curve and psychological and cosmetic issues.
Background
Scoliosis is a three‐dimensional deformity of the spine that results in the appearance of frontal curves, fixed vertebral rotations, and a flattening of the sagittal physiological curves (Parent 2005). While scoliosis can be secondary to other pathologies, in its most common form (70% to 80% of cases), the causes are unknown (SRS 2007). Scoliosis is generally diagnosed during childhood or early adolescence and evolves differently, depending on the age of the individual at diagnosis. Adolescent idiopathic scoliosis (AIS), discovered after nine years of age, is the most common diagnosis (Weinstein 1999). According to the Scoliosis Research Society, AIS is defined as a curve of at least 10°, measured on a standing radiograph according to the Cobb technique (SRS 2007). The prevalence of AIS is 2% to 3% in the general population. Almost 10% of those diagnosed with AIS will require some form of treatment, while up to 0.1% are at risk of surgery (Parent 2005; Lonstein 2006). Severe AIS is more commonly found in females. Typically, AIS does not cause any health problems during growth (except for extreme cases). However, the resulting surface deformity frequently has a negative impact on adolescents that can give rise to quality of life (QoL) issues and in the worst cases, psychological disturbances (MacLean 1989; Freidel 2002a, Freidel 2002b; Reichel 2003). Due to the progressive nature of the deformity, adolescent patients are generally treated when it is diagnosed. Furthermore, once the curve progresses, there are no treatments that succeed in full correction to a normal spine, and even reduction of the deformity is difficult (Danielsson 2001a; Lonstein 2006). If scoliosis surpasses a critical threshold, usually considered to be 30° Cobb, at the end of growth, the risk of health problems in adulthood increases significantly (Lonstein 2006; Negrini 2006b). Problems include reduced quality of life, disability, pain, increased cosmetic deformity, functional limitations, sometimes pulmonary problems, and possible progression during adulthood (Pehrsson 1992; Mayo 1994; Danielsson 2001b; Pehrsson 2001; Danielsson 2003a; Danielsson 2003b; Weinstein 2003; Negrini 2006b). Because of this, management of scoliosis also includes the prevention of secondary problems associated with the deformity (Negrini 2006a; Weiss 2006a; Weiss 2006b).
Treatment options for the prevention of AIS progression include exercises, bracing and surgery (Rowe 1997; Negrini 2003; SRS 2007; Lenssink 2005; Negrini 2005; Negrini 2006c; Rigo 2006a; Weiss 2006a; Weiss 2006b). Bracing is defined as the application of external supports to the trunk; these are usually rigid and applied with the aim of achieving maximum correction of the pathological curve (SRS 2007; Rigo 2006a). Treatment commences when the curve is diagnosed as progressive or exceeds a threshold, which is usually considered to be 30° Cobb (Negrini 2005; Lonstein 2006; Weiss 2006a; SRS 2007). Braces generally need to be worn for a considerable period of time per day (at least 20 hours) with treatment extending over several years, until the end of bone growth (Katz 2001; Landauer 2003; Rahman 2005; SRS 2006). All this causes a significant impact on the lives of children and adolescents (Fallstrom 1986; Noonan 1997; Climent 1999; Ugwonali 2004; Vasiliadis 2006a).
The theoretical background for spinal correction is that the application of mechanical forces that reduce the pathological compression on some portions of the vertebrae while increasing it on others will result in an unnatural loading that will facilitate proper spinal growth (Lupparelli 2002; Castro 2003; Weiss 2004). Although this is an old concept, the theory has been reinforced over time and was recently summarized in the "vicious cycle" hypothesis (Stokes 2006). The idea is independent of the etiological cause of scoliosis and only looks at the biomechanical factors of progression. An alternative hypothesis suggests that the use of braces leads to neuro‐motor re‐organization due to changes in external and proprioceptive inputs and movements caused by the rigid constraint of bracing (Coillard 2002; Odermatt 2003; Negrini 2006c). According to this hypothesis, braces are considered the drivers of movement while they increase external and internal bodily sensations: this permanently changes motor behaviors, even when the brace is removed, and can have a long‐term effect on bone formation.
Currently, the bracing of patients with AIS is controversial. In continental Europe it is considered standard treatment for mild to medium curves, while many centres in the UK and the USA do not brace patients (Rowe 1997; SRS 2007). Besides reports of detrimental effects on quality of life and psychological issues (Fallstrom 1986; Noonan 1997; Climent 1999; Ugwonali 2004; Vasiliadis 2006a), bracing has been widely criticized on the basis that there is a paucity of evidence that it has a positive effective on the natural history of the disease (Goldberg 1993; Dickson 1999a; Dickson 1999b; SRS 2007). To date, reviews on braces have been mainly narrative, have not considered the key issue of evaluating the methodological quality of the studies in the review, and have not included all existing studies (Rowe 1997; Lenssink 2005; Negrini 2007). A systematic review, conducted according to the current state‐of‐the‐art methodology, would significantly help clinicians decide whether the sacrifices required by children to wear braces are indeed worthwhile.
Objectives
The primary aim of this review is to evaluate the efficacy of bracing for adolescents with idiopathic scoliosis versus no treatment or other treatments, on quality of life, disability, pulmonary disorders, progression of the curve and psychological and cosmetic issues.
Methods
Criteria for considering studies for this review
Types of studies
Primary analysis will include all randomized controlled trials (RCTs) and quasi‐RCTs (QRCTs).
Secondary analysis will include non‐randomised trials and observational studies, included since it is anticipated that very few RCTs will be found. Observational studies must include a control group.
Types of participants
All patients who are 10 years of age or older (until the end of bone growth) when diagnosed as having adolescent idiopathic scoliosis will be included. Only studies in which bone maturity was evaluated by the Risser sign, wrist radiographs, or both will be included. Studies in which patients present with any type of secondary scoliosis, (congenital, neurological, metabolic, post‐traumatic, etc) diagnosed according to the SRS criteria (SRS 2006), will be excluded.
Types of interventions
The experimental interventions under consideration are all types of rigid and semi‐rigid braces (defined as the application of external supports to the trunk with the intention of providing significant corrective forces to the spine), worn for a specific number of hours per day for a specific number of years.
Control interventions will include: no treatment, specific therapeutic physical exercises, mobilisation and manipulation, electrical stimulation applied to muscles to submit the spine to corrective contractions, or surgery.
Types of comparison:
All possible comparisons will be considered. These include; patients receiving no treatment, patients receiving other non‐surgical treatments, patients receiving surgery, patients prescribed braces of different types and materials (such as the rigid versus semi‐rigid), and patients wearing braces for different lengths of time (such as night‐time only versus full‐time).
Types of outcome measures
The primary outcome measures will be: pulmonary disorders, disability, back pain, quality of life, psychological issues, and cosmetic. The secondary outcome measures will be clinical and radiographic parameters (Negrini 2006b). Very short (any result before the end of bone growth), short (results at the end of bone growth) and long term (results in adulthood) outcomes will be considered.
The following list of measurements is generic because the literature on the topic focuses mainly on Cobb degrees and scoliosis progression. Patient‐centred outcomes, even if very relevant to the individual (such as quality of life, or psychological issues) are rarely considered and there are no gold standard measurements. Only validated measurements will be included in this review.
Progression of scoliosis as measured by:
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Cobb angle in degrees (absolute values)
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Number of patients who have progressed by more than 5° Cobb
Quality of life and disability as measured by:
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specific validated questionnaires such as SRS‐22 (Asher 2003), SF‐36 (Asher 2003), BSSK (Weiss 2006c), BrQ (Vasiliadis 2006b)
Back pain as measured by:
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VAS and other validated specific questionnaires, use of medication
Psychological issues as measured by:
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specific questionnaires such as sub‐scales of SRS‐22 and SF‐36, BrQ
Cosmetic outcomes as measured by:
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objective surface measurements, including Bunnel degrees (and/or specific validated scales/questionnaires such as the Walter Reed Visual Assessment Scale (Pineda 2006)
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Topographic measurements e.g. ISIS (the integrated shape imaging system) (Weisz 1988), Quantec (Goldberg 2001), Formetric (Rigo 2006b).
Adverse effects, as outlined in identified trials, will also be reported.
Search methods for identification of studies
Electronic searches
We will undertake a comprehensive search to identify all relevant studies. We will search the following electronic databases:
1) The Cochrane Central Register of Controlled Trials (CENTRAL‐ The Cochrane Library, most recent issue), which includes the Cochrane Back Review Group Trials Register
2) MEDLINE (from 1966 to present)
3) EMBASE (from 1980 to present)
4) CINAHL (from 1982 to present)
The updated search strategy recommended by the Cochrane Back Review Group for RCTs (van Tulder 2003) will be used and adapted for cohort studies. The strategy includes subject headings (MeSH) and text words. These include methodological terms, disorder terms and treatment terms, and are listed in full for MEDLINE, EMBASE and CINAHL (Appendix 1; Appendix 2; Appendix 3). The remaining database will be searched with the strategy adapted appropriately.
Manual searches
The following strategies will also be included:
1) screen the reference lists of all relevant papers
2) search the main electronic sources of ongoing trials (National Research Register, meta‐Register of Controlled Trials; Clinical Trials).
3) search the Grey literature, including conference proceedings, PhD theses and unpublished work conducted by manufacturers that are likely to contain trials relevant to the review.
4) contact investigators and authors in this field for information on unpublished or incomplete trials.
All searches will include non‐English language literature and studies. The review team will assess studies in English, Italian, French, German, Japanese, Polish, and Greek for inclusion. They will contact the Cochrane Back Review Group editorial staff for help with studies published in other languages. When considered likely to meet inclusion criteria, studies will be translated.
Data collection and analysis
Study selection
Two review authors will independently evaluate the search results by reading the titles and abstracts. Potentially relevant studies will be obtained in full text and independently assessed for inclusion by two review authors, who will resolve disagreement through discussion. A third review author will be contacted if disagreements persist.
Assessment of the methodological quality
Two review authors will independently assess the internal validity of the included studies. The RCTs and QRCTs will be assessed according to the criteria recommended by the Cochrane Back Review Group (van Tulder 2003), as outlined in Additional Table 1. The studies will be classified as high quality (fulfilling six or more of the eleven methodological quality criteria and having a low potential for bias) or low (fulfilling fewer than six quality criteria and having a high potential for bias).
| Criteria/Definitions |
| A. Was the method of randomisation adequate? A random (unpredictable) assignment sequence. Examples of adequate methods are computer‐generated random numbers table and use of sealed opaque envelopes. Methods of allocation using date of birth, date of admission, hospital numbers, or alternation should not be regarded as appropriate. If the method of sequence generation will not reported the study will be scored as "unclear". |
The Newcastle‐Ottawa Scale (NOS) will be used to assess the observational studies. The NOS assesses three broad areas: selection bias, attrition bias, detection bias. See Additional Table 2 for details.
| criteria |
| Selection bias: |
Studies will be also be classified according to the Cochrane grading (A to D) for concealment of allocation. The latter will be reported in the Characteristics of included studies table. Studies with adequate allocation concealment will be classified as A, studies with unclear allocation concealment as B, studies with inadequate allocation concealment as C, and observational studies will be classified as D: criteria not used
The methodological quality will not be used as a criterion for inclusion. In order to assess the effect of the low quality studies, we will perform a sensitivity analysis, in which we will either include or exclude those assessed as 'C' from meta‐analysis.
Data extraction
A standardized data extraction form will be prepared and used to extract data from the included papers. Data on the population, study characteristics and results will then be extracted independently by two review authors. Any disagreement will be discussed and a third review author consulted if disagreements persist. Key findings will be summarized in narrative format and assessed for meta‐analysis where possible.
Data synthesis
Dichotomous outcomes will be analysed by calculating the relative risk (RR) for each trial, with the uncertainty in each result expressed with 95% confidence intervals (CI). Continuous outcomes will be analysed by calculating the weighted mean difference (WMD) or the standardized mean difference (SMD) with 95%CI. The outcome measures from the individual trials will be combined through meta‐analysis where possible (clinical comparability of intervention and outcomes between trials) using a fixed‐effect model unless there is significant statistical heterogeneity, in which case a random‐effects model will be used. A P ‐ value of the chi‐square test less than 0.05 indicates a significant statistical heterogeneity. Separate meta‐analyses will be performed for randomized and observational studies.
Regardless of whether there are sufficient data available to use quantitative analyses to summarize the data, we will assess the overall quality of the evidence for each outcome. To accomplish this, we will use an adapted GRADE approach, as recommended by the Back Review Group (Furlan 2008). The quality of the evidence on a specific outcome is based on the study design, methodological quality, consistency of results, directness (generalizability), precision (sufficient data) and reporting of the results across all studies that measure that particular outcome. The quality starts at high when high quality RCTs provide results for the outcome, and reduces by a level for each of the factors not met.
High quality evidence = there are consistent findings among at least two (high quality) RCTs with low potential for bias that are generalizable to the population in question. There are sufficient data, with narrow confidence intervals. There are no known or suspected reporting biases.
Moderate quality evidence = one of the factors is not met
Low quality evidence = two of the factors are not met
Very low quality evidence = three of the factors are not met
No evidence = no evidence from RCTs
Data analysis
Clinical relevance of results
The review authors will assess each trial for its clinical relevance by using the five questions outlined by Shekelle 1994 and recommended by the Cochrane Back Review Group (van Tulder 2003; Table 3). All important outcomes for each comparison will be discussed. The main conclusion will be clinical, because our main aim is to give clinicians state‐of‐the‐art information, according to relevant studies on this issue.
| Questions |
| 1. Are the patients described in detail so that you can decide whether they are comparable to those that you see in your practice? |
Comparison between primary and secondary analysis
Results obtained from the two analyses will be compared and contrasted, but the conclusions of the review will be based on the results of the primary analysis.
| Criteria/Definitions |
| A. Was the method of randomisation adequate? A random (unpredictable) assignment sequence. Examples of adequate methods are computer‐generated random numbers table and use of sealed opaque envelopes. Methods of allocation using date of birth, date of admission, hospital numbers, or alternation should not be regarded as appropriate. If the method of sequence generation will not reported the study will be scored as "unclear". |
| criteria |
| Selection bias: |
| Questions |
| 1. Are the patients described in detail so that you can decide whether they are comparable to those that you see in your practice? |
