Fifteen Years and 2530 Patients: The Evolution of Instrumentation, Surgical Strategies, and Outcomes in Adolescent Idiopathic Scoliosis in a Single Institution

摘要

BackgroundOver the past decade, the surgical treatment of adolescent idiopathic scoliosis (AIS) has established new techniques to reduce curve severity and shifted to include the regular use of pedicle screws. Few studies have focused on this evolving trend in AIS correction surgery. In this study, we investigated how the operative approach, instrumentation, and surgical techniques have changed over the past 15 years and to quantify the related improvements in AIS surgical treatment. MethodsThis is a retrospective review of a prospective AIS registry in a single center. Patient data were reviewed from January 2001 to December 2015. The age and surgical case distribution were recorded for each year. Trends in classification use, instrumentation types, levels of fusion, and surgical approaches were analyzed by year. The major Cobb angles and correction rates were compared between different instrumentations and surgical approaches. ResultsA total of 2530 patients with AIS (83.0% female) were included, with a mean age of 15.14 years. Most patients underwent surgery at 14 years of age (473 patients, 18.7%), followed by 15 years of age (468 patients, 18.5%). In our center, the classification of patients with AIS shifted from the King classification to the Lenke classification in 2005. The major baseline Cobb angle of the entire cohort averaged 50.99° and this mean Cobb angle decreased to 14.41° after surgery. The correction rates for the first 3 years (2001–2003) were less than 70%, whereas the correction rates for the rest of the years were all greater than 70%. In addition, significantly higher correction rates were observed in patients with Cobb angles <90° (72.93% vs. 55.61%,P< 0.001). A total of 218 anterior-only surgeries and 109 combined anteroposterior surgeries were performed; the remaining 2205 surgeries were performed with a posterior-only approach. The use of anterior-only and anteroposterior approaches trended to decrease after 2005. The correction rate of anterior-only approaches was significantly greater than posterior-only and anteroposterior approaches (77.86%, 72.51%, and 59.37%, respectively). In patients corrected with a posterior-only approach, the screw–hook hybrid construct was used in 342 patients, whereas the all-pedicle-screw construct was used in 1835 patients. The shift from hybrid to all-screw construct occurred in 2006. In patients with thoracic AIS, the correction rate was significantly higher in the all-screw group (73.26% vs. 67.76%;P< 0.001). ConclusionsConsistent improvement of major curve correction has been achieved by the spine community over 15 years. After stabilized coronal correction and fewer fusion levels, the next steps in this evolution are the restoration of sagittal profiles, especially the hypokyphosis seen in patients with Lenke 1, the posterior minimally invasive approach, and a fast-track return to activity.