Knee Replacement FAQ

What is the difference between minimally invasive knee replacement and traditional knee replacement?

In traditional knee replacement, an approximately 10 to 12 inch skin incision is made centered over the knee.  This is followed by making an incision into the quadriceps tendon above the knee, down the side of the kneecap and two inches below the joint and then the kneecap is flipped 180 degrees and off to the side (everted).  The knee is then bent up to expose the bones of the knee for resurfacing with the knee prosthesis. 

In the Mini-Incision and Quad Sparing incision total knee replacements, the incision is 4-6 inches.  The quadriceps tendon is not cut, nor is the kneecap flipped backwards.  In the mini-incision total knee replacement (the larger of the two MIS total knee techniques), a small incision of about 1 inch is made into the muscle fibers of the vastus medialis muscle--one of the four quadriceps muscles, leaving the quadriceps tendon intact. The quad sparing total knee replacement leaves all of the quadriceps muscles intact including the vastus medialis.  Both techniques result in a marked decrease in muscle and tendon damage, which in turn does not weaken the quadriceps muscle and allows a much quicker return to normal activity.

Is there a difference between the replacement knee prosthesis used in minimally invasive surgery and the one used in traditional surgery?

No, the prosthesis is the same. Dr. Zechmann uses the Smith & Nephew Profix system.  This prosthesis has a long track record in the United States and abroad. 

Will the knee replaced with minimally invasive surgery last as long as one replaced through traditional surgery?

Since the prosthesis is the same one as used in the traditional knee replacement surgery, there should be no difference in how long the prosthesis lasts - provided it is put in by an experienced knee surgeon using the same tried and proven techniques of proper sizing and positioning, as well as ligament balance.

How does Dr. Zechmann put anew knee prosthesis through such a small incision?

The mini-incision and Quad Sparing total knee replacement surgery is performed with specialized instruments which allow Dr. Zechmann and his assistant to move the smaller incision ‘window' around the knee joint to give access to the areas he is working on. These specialized instruments include custom retractors for holding tissue out of the way, a knee holder to allow infinite different angles of flexion, extension and rotation of the knee joint, and new cutting jigs that allow cuts to be made from the side of the knee where the incision is rather than from the front of the knee.

How would I benefit from the minimally invasive knee replacement?                            

Studies have shown that using the quadriceps-sparing MIS knee replacement technique allows patients to recover three times faster, have about one-third less pain, one-third the length of hospital stay, 30 percent less blood loss and 10 degrees more motion of the knee at the end of the first and second years after the surgery, than those who underwent the traditional knee replacement procedure.

What are the risks of the procedure?

The risks of the procedure are the same as with traditional knee replacement surgery.  These include infection, blood loss requiring transfusion, stiffness to the knee, prosthetic component loosening, and misalignment. Studies have shown 30% less blood loss with the quadriceps-sparing MIS knee replacement as well as 10 degrees more motion of the knee at the end of the first and second years after the surgery.

Who is a candidate for MIS knee replacement surgery?

Not everyone is a candidate for the MIS Quad Sparing total knee procedure.  The procedure is not possible in very over weight individuals, very heavily muscled individuals, patients with very significant ‘knock knees', or ‘bow legs' or in patients with significant contractures of their knees. Most patients are candidates for the mini-incision total knee procedure which does involve cutting a small portion of one of the quadriceps muscles. Other patients that may not be candidates include those with significant prior open knee surgery (not arthroscopic procedures) or patients that have hardware fixed to the bones just above or below their knee from prior injuries.

When can I get back to full activity?                                                            

Full return to activity will depend on several factors.  These include your overall physical condition and the condition of your knee prior to the surgery. If you have maintained good strength to muscles of your thigh and leg as well as adequate cardiovascular conditioning, you should be back to a walking program as early as two weeks after surgery.  Near full motion to the knee should be back by six weeks after surgery, although many patients have had the majority of their motion back by two weeks. Patients who have had MIS total knee replacement generally rehab about three times faster than patients who have had traditional knee replacement.

Will my insurance cover the minimally invasive hip replacement?

Yes, all insurances, including Medicare, pay for MIS total hip surgery. There is no difference in the surgical code used to bill for the MIS total hip surgery.  It is the same as for a traditional hip replacement.

When can I get back to full activity after my minimally invasive knee replacement?

Patients, with a few exceptions, are able to start putting full weight on the operative side the same day as surgery. Typically, patients are walking 100-200 feet by the second day after surgery.  A walker or crutches are recommended until patients feel confident enough and are stable enough to go to a cane - typically at one to two weeks after surgery.  Many of the younger patients are walking up to a mile without a cane or crutch by six weeks after surgery. At four months after surgery, a full golf swing is possible.

How long will I be in the hospital for my minimally invasive hip replacement?

This will depend on your age and level of fitness prior to the surgery.  If you have a spouse at home that can help with meals and household activities, it may be possible to go home as early as two or three days after surgery. 

If patients are older and live alone, a short stay in the Transitional Care Facility, a step-down hospital, may be appropriate for a period of seven to ten days prior to going home.

When can I drive after surgery?

Usually this is after about two to six weeks and you are not taking narcotic pain medications. Dr. Zechmann recommends that you can drive after knee surgery when you are comfortable getting in and out of you vehicle and are not using crutches or a walker.

When can I swim?

After knee replacement surgery you should wait 4-5 days after the staples are removed.

When can I return to work?

This depends on what type of employment you have and the procedure that was done.  Dr. Zechmann or Mr. Jarman will give you work restrictions after surgery and your employer may or may not be able to accommodate those restrictions.  Check with you employer prior to surgery.

Do I need antibiotics prior to dental work after surgery?

Only after joint replacement surgery is this required.  Dr. Zechmann follows the American academy of orthopedic surgeon's recommendation that you take antibiotics for two years after having joint replacement surgery.

When will my staples or sutures be removed?

Often times MIS incisions are closed with "plastics" type of closure.  This is done with absorbable suture material and steri strips.  If there are staples they will be removed in our office in approximately two weeks.  You will see Kirk Jarman, PA-C at that time.  If you go to a rehab facility they may take them out there.