Is Minimally Invasive Total Knee Arthroplasty Associated with Lower Costs Than Traditional TKA?

Background Studies of minimally invasive surgery (MIS) approaches to TKA have shown decreased postoperative pain, earlier return to function, and shorter lengths of stay in the hospital. However, it is unclear whether these differences translate into decreased costs or charges associated with care.

Questions/purposes We asked whether a minimally invasive approach to TKA is associated with lower inpatient charges and direct inpatient costs than the traditional approach.

Patients and Methods We retrospectively reviewed one high-volume arthroplasty surgeon’s first 100 minimally invasive TKAs with the last 50 traditional TKAs with respect to all perioperative inpatient medical and billing records. Total charges minus implants (which were excluded across groups), total direct costs, and individual cost centers were analyzed.

Results The mean nonimplant total charge was less for patients receiving a minimally invasive TKA than a traditional TKA ($13,505 versus $14,552). With the numbers available, there was a trend for lower mean direct cost for minimally invasive TKA ($6156) versus traditional TKA ($6410).

Conclusions The total inpatient charges associated with a minimally invasive TKA were less than those associated with a traditional TKA; however, the magnitude of the difference (7.2%) was modest, and there was no reduction in direct hospital costs. Other studies will need to determine whether any economic benefits associated with minimally invasive TKA accrue after discharge. The decision regarding whether to perform minimally invasive TKA should be made on clinical grounds, as the medical-economic case on the inpatient side is not compelling.

Level of Evidence Level II, economic analysis. See Guidelines for Authors for a complete description of levels of evidence.