The Spine Blog

Friday, April 25, 2014

Does the Assistant’s Level of Training Affect Outcomes in Scoliosis Surgery?

Residency and fellowship training programs are challenged on a daily basis to determine the most appropriate assignment of trainees to cases of varying difficulty. In spine surgery, where technical errors can lead to major irreversible complications, this can be even more difficult. Common sense indicates that cases with a more experienced assistant will go faster and with fewer technical difficulties than those with a more junior trainee. However, it is unclear if meaningful clinical outcomes are actually affected by this factor. Despite every training program struggling with this issue, there is very little literature looking at this topic. As such, Dr. Skaggs and his colleagues from Los Angeles wanted to determine the effect of the first assistant’s level of training on outcomes in adolescent idiopathic scoliosis (AIS) and neuromuscular scoliosis (NMS). To answer this question, they retrospectively compared outcomes for AIS and NMS patients stratified by the first assistant’s level of training (i.e. junior resident vs. fellow) in 200 patients with at least 2 years of follow-up. Similar to a prior study comparing outcomes in AIS between cases with an attending vs. resident first assistant, they found essentially no significant differences between the junior resident and fellow cases in AIS. The cases took about 30 minutes longer and involved 70 cc of increased blood loss in the resident cases, but these differences were not significant. In the NMS cases where there was a fellow assisting, OR time was about 45 minutes less and curves were corrected by about 10% more compared to the junior resident cases (both differences were statistically significant). Blood loss was about 90 cc more in the junior resident cases, but this difference was not significant, and there were no significant differences in transfusion rates. There were no significant differences in complications or any complications directly attributable to the inexperience of a junior resident. Based on these results, the authors concluded that complex cases may be better served by a more experienced first assistant, but it was unclear if a less experienced assistant led to any clinically meaningful adverse outcomes.


This study likely affirms anecdotal experience as well as supports typical practice patterns, namely that surgery goes somewhat faster and more smoothly with a more experienced assistant, yet a less experienced assistant rarely leads to any clinically important adverse events. Most training programs make efforts to cover more complex cases with more experienced assistants but, when this is not possible, junior level assistants are frequently utilized. As all surgeons who train residents and fellows know, there is a constant trade-off between training and efficiency. If efficiency was the only goal, then all cases would be staffed by two attending surgeons. On the other hand, if training was the only goal, then every step of every case would be done by a trainee. In the real world, training programs work to balance training and efficiency in a practical way that results in good patient care, efficient use of resources, and effective training. This article supports this practice and makes it clear that the use of junior resident assistants, even in complex cases, does not have a clinically meaningful adverse effect on outcomes. Research like this is important in studying common care processes as well as surgical training, and hopefully we will see more papers of this kind in the future.

Please read Dr. Skaggs’s article on this topic in the April 15 issue. Does this change how you approach assigning trainees to complex cases? Let us know by leaving a comment on The Spine Blog.

Adam Pearson, MD, MS
Associate Web Editor