I was able to find two randomized controlled trials, one small, the other smaller, comparing conventional and minimally invasive surgery. Neither found any difference in outcomes (although neither had much statistical power to find such differences.)
So this is yet another story of advertising directed at patients which goes beyond the available clinical evidence. Although most of the criticism of direct to consumer advertising is directed at pharmaceutical companies, this is not the only case of potentially misleading advertising done by hospitals (see post here).
Post Title → Hospitals Hype Hip Surgery