Minimally invasive total knee arthroplasty: pitfalls and complications.

Despite reports of complications, there has been tremendous interest in using minimally invasive surgery (MIS) for total knee arthroplasty (TKA). Over the past 10 years, we have used an MIS approach for all TKAs. In the study described here, we examined the complications of the first 1000 of these TKAs. These cases involved a minimal incision (mean, 10 cm), a quadriceps muscle-sparing approach, and a non-patellar-everting technique. The complications assessed included manipulations, reoperations, and component revisions. We also analyzed for deviations in radiographic alignment or radiographic failures. There were 45 clinical complications-25 manipulations under anesthesia, 12 arthroscopic procedures for painful patellofemoral crepitus (mostly for an initially nonvisualized retained lateral band), and 8 operative explorations for various component problems. Radiographically, there were 3 impending component failures-2 tibial and 1 femoral. Excluding manipulations, there was a significant decrease in operative complication rate from the first 200 cases (6.0%) to the next 800 cases (1.0%), with overall complication rates similar to those of a control cohort treated with traditional surgical techniques. From this analysis, the major concern was potential tibial component loosening, which may be related to decreased exposure and possibly poor cement pressurization. Despite the low complication rate, this study yielded insights into further potential improvements in using this MIS technique for TKAs.