It really does not matter what style of compression garment you wear post tummy tuck as long as it fully overs the abdominal area. Above the knee would be fine, as would strictly just an abdominal one without any legs attached.
Strictly from a scientific standpoint, below the knee has been found to perform just as well as above the knee. A tummy tuck increases the intra-abdominal pressure and increases the risk of blood clots and DVT slightly over other surgeries due to slowing the blood flow from the legs by a very small percentage i some patients.
Most of this small increase in DVT occurs either during surgery or over the next 2-3 days as patients are less active. I recommend patients be up and moving their legs for at least a few minutes a few times a day as soon as possible after surgery, as a preventative measure. Nevertheless, your surgeon may have another viewpoint and you should adhere to their instructions as they are responsible for your after care.
This usually does not make a difference however I would make sure you discuss this with your plastic surgeon because he or she may have a particular reason for you wearing a particular garment after surgery. Good luck.
Scientifically, it makes no difference. Logistically it might. Sometimes patients wear knee highs that are quite tight at the knee which acts like a tourniquet. That is bad as it can slow the venous outflow and actually increase your risk of a DVT. I recommend you follow your surgeon's instructions as she/he knows your case best.
I appreciate your question.
I would recommend that you discuss this question with your surgeon as every surgeon has their own respective post op protocol for his/her patients. Your surgeon is your best resource as he/she is most familiar with your medical history and how you are healing following surgery.
The best way to assess and give true advice would be an in-person exam.
Please see a board-certified plastic surgeon that specializes in aesthetic and restorative plastic surgery.
Best of luck!
Board Certified Plastic Surgeon
Director-Beverly Hills Breast and Body Institute