Round Table Discussion of MIS Total Knee Arthroplasty
Giles R. Scuderi: Minimally invasive surgery (MIS) total knee arthroplasty (TKA) has become a popular surgical technique. Surgeons are performing the procedure through smaller skin incisions and limited arthrotomies. Yet this is not a technique for all patients and all surgeons. I have gathered a group of experts who will share their experiences. This panel includes Mark Pagnano, Steven Haas, Richard Berger, Alfred Tria, and Peter Bonutti. Let us start this discussion with patient selection. My own experience has shown that MIS total knee arthroplasty is more applicable to a thin female patient with minimal deformity and good preoperative range of motion. Mark, is there a way of determining who is an ideal candidate for a minimally invasive total knee?
Mark Pagnano: For me, the easiest patient is the elderly female patient who is slightly overweight and has moderate angular deformity with a reasonable range of motion. The patient who is somewhat overweight has some of that adipose tissue distributed within the muscle and that makes the muscle and soft tissue easier to mobilize during surgery. A moderate angular deformity allows me to do some ligamentous release early in the case and that facilitates both visualization and the placement of retractors under direct vision to protect the collateral ligaments and the posterior neurovascular structures. A small flexion contracture is of no concern but I like to see at least 100° of flexion. Finally, the ideal patient will require tibial and femoral implant sizes that are in the small to medium size range; the largest implants often have a dimension that approaches the skin incision size and those are difficult to maneuver into place gracefully.