325 East Sonterra Blvd.
Clinic: Suite 120
Administrative Office: Suite 220
San Antonio, TX 78258
Phone: (210) 614-5100 / Fax (210) 614-5103
Adam I. Harris, M.D.
Frequently asked questions:
What is MIS and Tissue Sparing Surgery
MIS stands for Minimally Invasive Surgery. It is a term that is now so overused that it is nearly meaningless. It is often confused with minimal or mini incision surgery. The concepts are entirely different. The mini or minimal incision surgery makes a smaller incision in the skin, but does basically the same operation underneath the skin as the standard procedure. Surgeons can often be heard saying that incisions heal “side to side, not end to end.” By this they mean that a one inch incision heals in exactly the same amount of time as a three or ten inch incision. This is true. Doing a surgery originally designed for a ten or twelve incision through a three inch incision, for the most part just makes it more difficult to do, and offers little (if any) benefit to the patient beyond improved appearance of the scar. In the long run, the function of the joint is likely no better and the recovery no quicker than a standard approach. Further, the accuracy of the position of the implants may be not as good as the standard incision.
By contrast, Tissue Sparing Surgery better conveys the key concept where patients really benefit. It refers to the manner by which the muscles and tissues underneath the skin are handled. The less damage created on the way in, the less there is to repair on the way out, and the more rapid the rehabilitation should be. Similarly, the less force required to perform the surgery, the less pain that the patient should have afterwards. Tissue sparing techniques are designed to minimize damage to local structures and minimize the force required to perform the procedure. It happens that most of the incisions are also smaller, though this is not the initial intent of the procedure. There is always adequate exposure to properly perform the surgery.
Arthroscopic surgery is, for example, “Tissue sparing”. In skilled hands, the implant positioning, the recovery and the ultimate outcomes of most arthroscopic surgeries are as good or better than those of the more traditional open techniques. The same is true of joint replacement, even though joint replacement is not (yet) available by arthroscopic techniques.
How long are the incisions in MIS/Tissue Sparing hip and knee surgery?
First, if you haven’t already, please read “What is MIS and Tissue Sparing Surgery” above. Briefly, the incisions are as long as they need to be, and no longer. These procedures and the instruments for them are designed for smaller incisions. The incision still will vary with the size of the patient. The five foot tall female with small bone structure and no “extra weight” will need a smaller incision for her knee replacement than the six foot six inch retired linebacker. That being said, the knee replacement incisions are between four and six inches normally. The direct anterior total hip arthroplasty employs a single incision of about three and a half to four inches.
How can the surgeon see to do MIS/Tissue Sparing surgery?
A common argument against MIS/Tissue Sparing surgery by those who don’t (or often can’t) do MIS/Tissue Sparing surgery is that they cannot see enough to do the surgery properly. This is true only for small incisions when paired with standard procedures. The MIS/Tissue Sparing procedures and instruments are designed to allow the surgeon to see enough to do the surgery properly. Structures commonly exposed during standard approaches that are not critical for orientation are not exposed during tissue sparing surgery.
What is different abut the way that the muscles are handled?
Many surgeons have posted video footage of traditional hip or knee replacement surgery on the internet. For those of you who have seen these videos, you may have noted that there is a great deal of brute force employed. Orthopaedic surgeons lovingly refer to this as “brutane”. Also, the leg is twisted or turned into all sort of odd and unusual positions. Lastly, traditional techniques often detach muscles or cut far into tendons so as to obtain adequate exposure.
By contrast, MIS/Tissue Sparing does not cut into tendons. MIS/Tissue Sparing uses different approaches, different instruments, and different more gentle positioning of the leg. Therefore, the MIS/Tissue Sparing surgeon leaves the “brutane” at home. This gives rise to less inflammation, and less pain post operatively. Whether by this exact mechanism or by some other mechanism, the patient who undergoes MIS/Tissue Sparing surgery generally recovers normal function much more rapidly than their traditionally operated friends.