Is It Growth or Natural History? Increasing Spinal Deformity After Sanders Stage 7 in Females With AIS

摘要

Background: Accurate prognosis and treatment decisions in adolescent idiopathic scoliosis (AIS) demand a reliable radiographic marker of growth cessation. Specifically, Sanders Stage 7 (SS7) is a useful marker of spine growth cessation in females and is proposed as a bracing endpoint. The purpose of this study was to determine the amount of curve progression noted in female individuals with AIS after achieving SS7. We hypothesize that a subset of patients continues to progress at a greater rate than the natural history at SS7. Methods: This retrospective review included female patients with AIS treated at a single institution from May 2008 to 2018. Patients required a hand radiograph demonstrating SS7 and concurrent spine radiograph measuring 50 degrees or had surgery at 2-year follow-up. Receiver operating characteristic curve analysis identified a threshold of 39.5 degrees curvature at SS7 associated with progression to >50 degrees or surgery (area under the curve=0.94, P 40 degrees did have additional height gained (2.1?cm; SD 1.5), but this was not different than those 0.05. In addition, no other variables had statistically significant association with those that progressed ( P >0.05). Conclusions: A curve >40 degrees at SS7 is at high risk for progressing to a curve measuring >50 degrees or requiring surgery. Those with curves below this threshold still have potential to make clinically significant progression after skeletal maturity. Follow-up of patients beyond SS7 is essential for curves measuring >40 degrees. Reaching SS7 with a curve <50 degrees may not be the endpoint for curve progression, even if predictive of the end of spinal growth. Level of Evidence: Level III—retrospective research study.