A variety of treatment options are available when patients undergo medial thigh lift surgery. As a general rule, as medial thigh skin sag becomes more severe, the incisions utilized to correct this problem advance further down the leg.
In mild cases, the incisions are confined to the groin crease. When this problem becomes more extensive, skin resection will be necessary in multiple dimensions. This necessitates an extension of the groin incision along the inner thigh towards the knee. In severe cases, this incision may actually extend vertically across the medial knee.
Since knee incisions can be problematic, they're avoided whenever possible. It would be extremely unusual to utilize an isolated knee incision.
It's important to realize that thigh lift surgery needs to be tailored to meet the patient's aesthetic goals and address their anatomic findings. For this reason, it's important to consult a board certified plastic surgeon with experience in this area.