Successful total knee arthroplasty depends in part on reestablishment of normal lower extremity alignment, proper implant design and orientation, secure implant fixation, and adequate soft-tissue balancing and stability.
The operative technique for the standard total knee arthroplasty (TKA) involves a skin incision between 16 cm (6 in) and 30 cm (12 in). In comparison, when Dr. Luke Vaughan started talking about a "shorter incision" in 2000 for primary total knee arthroplasty, he suggested that 10 cm (4 in) was a good starting point and the incision could be extended if needed. Since that time, some surgeons are reporting that a skin incision for the MIS Quad-Sparing technique may be as short as 8 cm (3 in).
Total knee arthroplasty using a less invasive technique is suggested for non-obese patients with preoperative flexion greater than 90 degrees. Patients with varus deformities greater than 17 degrees or valgus deformities greater than 13 degrees are typically not candidates for a smaller incision technique.
Arthrotomy Skin Incision
MIS Midvastus Arthrotomy
The midvastus arthrotomy is a muscle-splitting approach that involves a 1.5 to 2 cm snip into the vastus medialis obliquus where it approaches the quadriceps tendon. The patella may be subluxed or, if desired, it may be everted if there is no tension on the patellar tendon. The incision can be extended easily if more visualization is needed. This approach facilitates rapid and reliable closure of the knee joint.
