2013 ISAKOS Congress : Leg alignment and tibial slope after minimal invasive total knee arthroplasty: a prospective, randomized radiological study of intramedullary versus extramedullary tibial instrumentation.

51 patients with osteoarthritis of the knee were randomized to receive either intramedullary or extramedullary tibial instrumentation, during minimal invasive surgery in total knee arthroplasty (MIS-TKA). Leg alignment and tibial slope were measured throughout the course of the study in order to determine which instrumentation resulted in better alignment, and as a result, increased TKA survival rate. By the end of the 12 month study, the study determined that there was no significant difference in leg alignment between MIS-TKA with intramedullary or extramedullary tibial instrumentation, but MIS-TKA with extramedullary instrumentation was significantly better at restoring the tibial slope.