Research quality in scoliosis conservative treatment: state of the art

For years we have waited for a Randomized Clinical Trial (RCT) to finally validate the effectiveness of brace treatment for scoliosis, with the evidence up until now based only on prospective observational studies [8, 9]. After a first failed attempt [5], a partially randomized trial with a large observational arm showed scoliosis bracing effective in preventing scoliosis surgery, with only 3 patients needed to prevent one surgery [6]. More recently, another RCT comparing bracing and observation has been published, even though it has a small sample population and includes low magnitude curves [10]. It is evident from these two papers that in the field of conservative scoliosis treatment, patients and families want to decide what to do about their therapy. They do not accept the chance of being randomized to the no-treatment arm, and this makes RCTs almost impossible to perform [5, 6]. Moreover, there is now a serious ethical problem with such research. The recruitment of patients in these two RCTs was stopped by their ethical committees because of the dramatic effect of treatment over observation, and this in the end makes it unethical to propose new RCT studies [6, 10]. But there are different study designs that can be adopted, and if performed correctly they can be at least as reliable as RCTs. Well designed prospective controlled studies have demonstrated that they are consistent in their findings with RCTs, even in very high magnitude curves [11], with the advantage of being more economical, more generalizable, and less affected by an overestimation of the effect size [12].

Although bracing is now supported with the new RCTs, significant doubts still exist about another pillar of conservative scoliosis treatment: Exercise Therapy. Although many systematic reviews have concluded that exercises for scoliosis treatment are effective [13, 14], a recent Cochrane review stated that there is lack of high quality evidence in favor of this [15]. Only one of the papers included in the Cochrane review was a RCT, however, many clinical and methodological limitations were detected [12], thus lowering its level of evidence. Nevertheless, the dogma of exercise being ineffective for scoliosis is based on a myth and not science, since no data showing exercise to be ineffective has been published either [16]. “No evidence” doesn’t mean no efficacy; it only means an absence of studies. But now more studies are beginning to be published. Recently, a randomized trial focused on the main principle of modern scoliosis-specific exercise treatment, which is active self correction, showed this movement to be fundamental to obtain the best results [17‐19]. That paper confirmed the recommendations of the International guidelines for conservative scoliosis treatment [20], and those of a previous consensus about scoliosis-specific physical therapy exercises, which identified the importance of the principle of self correction [21]. So, the level of research about scoliosis-specific exercise (SSE) provided by a PT is increasing, and hopefully will eventually demonstrate which approaches are most effective [22].

There are some methodological points that must be raised in the attempt for new effective conservative treatments able to reduce the burden of therapies on young patients [9, 20]. In fact, while sound research will convince even the skeptics, biased studies can damage the entire field of conservative scoliosis treatment. Physicians and allied health professionals in the field want to shift their treatment to provide the most effective ones possible, but biased research does not allow this evolution. Therefore, there are some criteria that should be followed in order to collect reliable and useful data.

In the end, we do not help patients if we cause confusion in the field of conservative treatment.. In fact, during the years bracing was discredited (now apparently finished due to sound and appropriate research), how many patients were treated with the so-called “wait and see approach” that in the end meant only waiting for surgery? This is even more striking when it is recognized that the new epidemiological data indicate that 58 % of patients between 20° and 40° will progress to surgery, or above 50° of Cobb Angle, if left untreated [6]. Now, the scientific challenge in the world of conservative scoliosis treatment is focusing on scoliosis-specific physical therapy exercises. Biased research in this field has the same potential to damage the best studies [15], including a recent high quality RCT [17, 18] and the previous one already existing [35].