Minimally Invasive, Quadriceps-Sparing Total Knee Arthroplasty

Seth S. Leopold, MD

Advocates of minimally invasive total knee arthroplasty have cited faster recovery times, shorter hospital stays, and improved short-term functional outcomes as the principal reasons for adopting these new approaches, and their originators have claimed that no compromises occur with respect to component positioning or to the soft tissues about the knee. Critics have raised questions about implant malalignment and the length of the learning curve. There is no standardized minimally invasive approach for total knee arthroplasty. Similarly, there is no agreement as to whether an approach that allegedly spares the quadriceps but goes a centimeter or two (or more) into the medial-sided soft tissues should be described as a "quadriceps sparing," a "mini midvastus," or a "mini subvastus" approach. In a recent JBJS manuscript, Seth S. Leopold, MD of the University of Washington compared his first 100 minimally invasive total knee arthroplasties with fifty procedures performed through a medial parapatellar approach, with respect to operative times, implant alignment, and clinical outcome. Clinical outcome data in this series tended to support the claims of proponents of minimally invasive total knee arthroplasty suggesting accelerated recovery, but they also echoed the concerns of one skeptical report that clinical results tend to converge with those after use of a traditional approach once outside the early postoperative period. Dr. Leopold also notes the minimally invasive total knee arthroplasty learning curve in this series was approximately fifty procedures. The principal differences between the minimally invasive technique and the traditional total knee arthroplasty approach include the following: there is no eversion of the patella in the minimally invasive operation (instead, lateral patellar subluxation during tibial and femoral preparation is used); freehand resection of the patella is done with use of the same landmarks as in the traditional total knee arthroplasty group, but the cut is made with the patella tipped 90°; the tibiofemoral joint is not dislocated during bone preparation (the tibial cut is made in situ with a cutting block positioned anteromedially); no knee is flexed to >90° until trial components are in place and range-of-motion testing is performed; and a shorter anteromedially placed incision, rather than a longer directly anterior incision, is used. On the basis of his results, Dr. Leopold is cautiously optimistic about minimally invasive total knee arthroplasty and feels it may have a role in the hands of high-volume arthroplasty surgeons who are willing to invest the time to learn and practice the procedure.

Material Covered

• Indications
• Contraindications
• "Mobile Window" Concept
• Ligament Balancing
• Postoperative Protocol

Specifications

• Total Run Time: 30:25 minutes
• Catalog Number: 5105
• VJO Publication Date: December, 2008