Mini-Incision Total Knee Replacement
A mini-incision total knee replacement, or arthroplasty, is a surgical procedure to replace a damaged, dysfunctional knee joint using minimally invasive techniques. The knee, being a weight-bearing joint, is especially prone to injury and degenerative disease. The knee is a hinge joint where the femur (thigh bone) and tibia (shin bone) meet. The patella (knee cap) glides over the femur when the knee moves. In a healthy joint, a layer of smooth cartilage cushions the bone ends, working together with muscles, tendons and ligaments to allow the knee to bend easily.
When the cartilage, or protective cushion, between the bones wears away, serious pain and stiffness result. In a total knee replacement, the damaged ends of the bones are removed and replaced with a prosthesis made of metal and plastic parts. These artificial parts allow the joint to move smoothly so the patient experiences pain relief and restored range of motion.
Benefits of Mini-Incision Total Knee Replacement
When a patient continues to suffer pain and restricted mobility after more conservative treatments, a mini-incision total knee replacement is usually the preferred option. There are several advantages to this minimally invasive surgery over traditional procedures, including:
- Shorter incisions
- Less bleeding and pain
- Smaller scars
- Less cutting of other muscles, tendons and ligaments
- Shorter hospital stays
- Shorter recovery periods
One of the primary advantages of mini-incision knee replacement is that it requires less interference with the quadriceps muscle, allowing smoother movement of the replaced joint.
The Mini-Incision Procedure
Recent advances in surgical technology make it possible to perform minimally invasive joint replacements. Traditional knee replacement surgery involves an 8 to 12 inch incision. The incision made during a mini-incision knee replacement procedure is only 4 to 6 inches in length and so does not extend as far up the quadriceps muscle, allowing patients to bend their knee more easily after the procedure.
This surgery may be performed as an inpatient or outpatient procedure. During the surgery, several small incisions are made in the knee to access the joint and allow the surgeon to remove the damaged bone and cartilage on the end of the femur and tibia. Precise removal is essential to achieving successful results. Once the damaged tissue is removed, the prosthetic device is inserted and may be either cemented or pressed into place. Cemented knee replacements are most commonly used, and are fixed into the joint for immediate support. The other type, press-fit knee replacements are designed to have the surrounding bone grow into the implant for long-term joint stability.
Mini-incision total knee replacement surgery is complex. Great surgical skill is required to make certain that the replaced knee functions much the way a natural healthy knee does.
Recovery from Mini-Incision Replacement
Patients usually experience immediate relief from the joint pain suffered before the replacement. However, there will be some post-operative discomfort, which can be managed with prescribed pain medication.
Physical therapy starts as soon as possible after the procedure to speed healing and ensure that the patient regains full use of the joint. The patient progresses from using a walker. crutches, or a cane to practicing walking on stairs and slopes under the guidance of a physical therapist. Typically, the patient also makes use of a continuous passive motion (CPM) machine during physical therapy sessions in order to reduce recovery time, diminish the risk of muscle contracture, and avoiding straining the new joint. Home exercises are assigned to hasten the recovery process.
Today's replacement joints last for about 20 years in most patients. Depending on the activity level of the patient, some joints wear out sooner than others. Many patients, especially younger ones, may require an additional procedure at some point. The great majority of patients who have undergone mini-incision total knee replacements report satisfaction with the results, enjoying restored mobility and relief from the chronic pain they previously suffered.
Risks of Mini-Incision Replacement
Although mini-incision total knee replacement is a safe procedure for most patients, there are risks associated with all surgical procedures. While complications to this operation are rare, they include: infection, blood clot, nerve damage, implant rejection and adverse reaction to medication or anesthesia. The mini-incision procedure has also been demonstrated to present a somewhat greater risk of misalignment than traditional surgery.