Minimally Invasive Transforaminal Lumbar Interbody Fusion: Cost of a Surgeon's Learning Curve.

Abstract Background Minimally invasive transforaminal interbody fusion has become an increasingly common approach in adult degenerative spine disease but is associated with a steep learning curve. Objective To evaluate the impact of the learning experience on mean procedure time and mean cost associated with each procedure. Methods We studied the first one-hundred consecutive minimally invasive transforaminal interbody fusion procedures of a single surgeon. We performed multivariable linear regression models, modelling operating time and costs in function of the procedure order adjusted for patients’ age, gender and number of surgical levels. The number of procedures necessary to attain proficiency was determined through a k-means cluster analysis. Finally, the total excess operative time and total excess cost until obtaining proficiency was evaluated. Results Procedure order was found to impact procedure time and mean costs, with each successive case being associated with progressively less procedure time and cost. On average, each successive case was associated with a reduction in procedure time of 0.97 minutes (95% CI=0.54-1.40; p Conclusion Successive cases were associated with progressively less procedure time and mean overall and surgical costs, until a proficiency threshold was attained.