A Genetic Test Predicts Providence Brace Success for Adolescent Idiopathic Scoliosis When Failure Is Defined as Progression to >45 Degrees

Clin Spine Surg. 2016 Apr;29(3):E146-50. doi: 10.1097/BSD.0b013e3182aa4ce1.

Abstract

Study design: Retrospective cohort.

Objective: To determine whether a genetic test is associated with successful Providence bracing for adolescent idiopathic scoliosis (AIS).

Summary of background data: Genetic factors have been defined that predict the risk of progression of AIS in a polygenic fashion. From these data, a commercially available genetic test, ScoliScore, was developed. It is now used in clinical practice for counseling and to guide clinical management. Bracing is a mainstay of treatment for AIS. Large efforts have been made recently to reduce potential confounding across studies of different braces; however, none of these have considered genetics as a potential confounder. In particular, ScoliScore has not been evaluated in a population undergoing bracing.

Methods: We conducted a retrospective cohort study in which we identified a population of AIS patients who were initiated with Providence bracing and followed over time. Although these patients did not necessarily fit the commercial indications for ScoliScore, we contacted the patients and obtained a saliva sample from each for genetic analysis. We then tested whether ScoliScore correlated with the outcome of their bracing therapy.

Results: We were able to contact and invite 25 eligible subjects, of whom 16 (64.0%) returned samples for laboratory analysis. Patients were followed for an average of 2.3 years (range, 1.1-4 y) after initiation of the Providence brace. Eight patients (50.0%) progressed to >45 degrees, whereas the other 8 patients (50.0%) did not. The mean ScoliScore among those who progressed to >45 degrees was higher than that among those who did not (176 vs. 112, P=0.030).

Conclusions: We demonstrate that a genetic test correlates with bracing outcome. It may be appropriate for future bracing studies to include analysis of genetic predisposition to limit potential confounding.

MeSH terms

  • Adolescent
  • Braces*
  • Child
  • Disease Progression*
  • Female
  • Genetic Testing*
  • Humans
  • Linear Models
  • Male
  • Scoliosis / therapy*
  • Treatment Failure