The Prolo Scale: history, evolution and psychometric properties.

Background: The Prolo Scale (PS) is a widely accepted assessment tool for lumbar spinal surgery results. Nevertheless, in the literature there is a dearth of consensus about its application, interpretation and accuracy. The purpose of this review is to investigate the evolution of the PS from its introduction in 1986 to the present, including an analysis of different versions of the scale and research on the existing studies investigating its psychometric properties.