Characterizing the Surgeon Learning Curve in Instrumented Minimally Invasive Spinal Surgery: Does the Evidence Account for Training and Experience? A Systematic Literature Review.

Abstract

This was a systematic literature review. The purpose of this systematic literature review was to aggregate all evidence characterizing the learning curve of instrumented minimally invasive surgery (MIS) techniques in spinal surgery and summarize what, if any, consideration has been given to surgeon training and experience. MIS techniques have become prevalent in spine surgery given the ability to diminish the intraoperative footprint, translating to quicker patient recovery, and improved long-term outcomes. However, technical demand on the surgeon can be significant, particularly during the procedural adoption (learning curve) phase. Many studies have sought to quantify the duration and severity of these learning curve phases, with the intent to characterize MIS procedural appropriateness and safety. However, while these studies are robust regarding outcome metrics, it is not well understood whether they adequately characterize surgeon training and experience. A systematic literature review was performed in the PubMed and MEDLINE databases in accordance with the PRISMA guidelines. All inclusion articles were screened for statements regarding surgeon experience/training. Statements were further classified by the types of metrics/variables utilized to establish a contextual history of experience/training. Descriptive statistics were reported. Initial search criteria yielded 458 articles, 12 met final inclusion. Seven articles (58.3%) attempted a summary statement of experience which acknowledged at least one of the following metrics: total years in practice (41.7%), years/number of cases performed using the traditional/gold-standard technique (16.7%), specification of residency/fellowship training (16.7%), use/nonuse of cadaveric or course/lab training (16.7%), and/or design of operating team (8.3%). No articles considered experience as a quantitative variable in their study analyses. Spine MIS learning curve studies for instrumented fusion procedures provide inadequate context/characterization of surgeon experience and training. Future efforts leveraging learning curve methodology utilized in other surgical specialties would be beneficial.