Study DesignModified Delphi study.ObjectivesTelementoring, the practice of providing remote guidance and teaching from a distance using telecommunication technology, has demonstrated feasibility and value in assisting surgeons in remote locations. However, limited evidence exists regarding its effectiveness in improving surgeon performance. This study aimed to develop metrics to assess spine surgeon performance in scoliosis surgery, potentially within the context of a telementoring training program.MethodsTen expert spine surgeons participated in a four-round modified Delphi process including both online and in-person meetings. The resulting metrics were validated for objective assessment by eleven surgeons, who reviewed and rated a video recording using the established rubric.ResultsThe final set of metrics, comprising 50 procedural steps and 28 error categories, was unanimously approved by the panel. Additionally, the panel agreed that utilizing cameras, smart lenses, and output from intraoperative imaging monitors would provide sufficient visibility for assessing both steps and errors.ConclusionsA set of assessment metrics for adolescent idiopathic scoliosis surgery was successfully defined and validated by reviewing example videos. The longer-term research objective is to employ this rubric to assess surgeon's performance throughout a telementoring program, thus assessing its educational impact. The rubric could also be used in other contexts, such as live surgical observation.