Review Question - QID 8775

Bracing a patient with a 25 degree curve and a Sanders stage of 3 is associated with only a 29% risk of curve progressing to >50 degrees, which is commonly the threshold for surgical indication.

Bracing is the most common non-operative treatment for AIS. The currently accepted indications for bracing include patient age of 10-15 years, skeletal immaturity defined by Risser grade 0-2, and a Cobb angle for the largest curve between 20 and 40 degrees. Predicting which patients will benefit from bracing has been a clinical challenge, but indications may become more selective in the future using the Sanders staging method.

The Sanders staging system of maturity when applied to patients with AIS assists in predicting the probability of scoliosis progression beyond 50 degrees despite bracing for Lenke type I and III curves. The authors used curve magnitude, a modification of the Tanner-Whitehouse-III skeletal maturity staging (based on anteroposterior hand radiographs), and the curve acceleration phases in females to predict curve progression. The radiographic features of stage 3 are complete capping of the phalangeal epiphyses. For patients with a 25 degree curve and Sanders radiographic stage 1, the risk of curve progression to >50 degrees is 99% (even with bracing), for stage 3 this risk decreases to 29%, and for stage 4 through 8 the rate is 0%

Weinstein et. al. demonstrated the clear efficacy of bracing in a multi center partially-randomized prospective cohort study. 75% of patients who were braced were treated successfully defined by curve progression to <50 degrees by skeletal maturity, compared with 42% of patients assigned to the observation only cohort. Benefits of bracing were increased with longer hours of brace wear.

Sanders et. al. published their radiographic classification system based on the Tanner-Whitehouse III descriptors. It demonstrates acceptable inter-observer reliability and is prognostic of bracing failure. While good at predicting brace failure, it has not been designed to necessarily predict the success of brace treatment.

Illustration A the prognosis of various thoracic curves according to Sanders maturity stage.

Incorrect Answers:
Answer 1: A curve of 10 degrees would not meet the criteria to initiate bracing, as there is minimal risk of progression.
Answer 2: A thoracic curve of 10 degrees with Sanders stage 5 would also not meet criteria to start bracing.
Answer 4: Even with bracing, this curve is 99% likely to progress to >50 degrees.
Answer 5: Even with bracing, this curve is 100% likely to progress to >50 degrees.