Critical review of minimally invasive approaches in knee arthroplasty.

Despite high survivorship for total knee arthroplasty, many reports have described low patient-satisfaction rates. Standard parapatellar approaches have been linked with decreased quadriceps muscle strength, which may in turn lead to prolonged rehabilitation and altered kinematics. Although technically demanding, minimally invasive techniques offer the potential for shorter recovery times and improved strength. Our purpose was to compare perioperative factors, the clinical and radiographic outcomes, complications, and survivorship of several minimally invasive approaches to each other and to the conventional medial parapatellar approach. A total of 23 level I or II studies were reviewed. There were no statistically significant differences in perioperative factors, clinical or radiographic outcomes, survivorship, or complication rates between patients the various minimally invasive approaches to a standard approach. The only significant difference observed was in recovery of quadriceps muscle function (shorter in patients who had a minimally invasive approach). The minimally invasive lateral approach had more complications than the other minimally invasive approaches. The mini-midvastus approach had the best clinical outcomes at 1 and 3 months when compared with other minimally invasive approaches and standard approaches. The mini-subvastus approach had the lowest rate of complications, overall. Further multicenter randomized trials are needed to determine the minimally invasive approach that best improves outcomes while minimizing complications.