Minimally Invasive TKA Benefits Are Cosmetic, Not Clinical

When Verburg et al. designed their randomized clinical trial, published in the June 15, 2016 edition of The Journal of Bone & Joint Surgery, they hypothesized that a mini-midvastus (MMV) approach to total knee arthroplasty (TKA) would yield better outcomes than a conventional approach. However, during short- and mid-term follow-up (up to 5 years postoperatively) on 84 TKAs (42 in each group), the researchers found no relevant clinical or radiographic differences between the two groups, both of which received the same brand of posterior-stabilized implant.

On average, the MMV procedure took 6 minutes longer, and those in the MMV group had better range of motion on postoperative day 3. On the downside, more wound-healing problems such as blisters were observed in the MMV group, especially in large male patients, which the authors attribute to soft-tissue interactions caused by the use of necessarily large components with small incision lengths.

Verburg et al. concluded that “the advantage of the MMV approach was merely a smaller scar,” and they do not recommend MMV or other minimally invasive/quadriceps-sparing approaches for “larger patients or muscular men.”