Stratifying outcome based on the Oswestry Disability Index for operative treatment of adult spinal deformity on patients 60 years of age or older: a multicenter, multi-continental study on Prospective Evaluation of Elderly Deformity Surgery (PEEDS)

Christopher J. Nielsen, Stephen J. Lewis, Colby Oitment, Allan R. Martin, Lawrence G. Lenke, Yong Qiu, Kmc Cheung, Marinus de Kleuver, David W. Polly, Christopher I. Shaffrey, Justin S. Smith, Maarten Spruit, Ahmet Alanay, Yukihiro Matsuyama, Thorsten Jentzsch, Anna Rienmüller, Hananel Shear-Yashuv, Ferrán Pellisé, Michael P. Kelly, Jonathan N. Sembrano, Benny Dahl, Sigurd Berven, AO Spine Knowledge Forum Deformity