There are many reasons for wanting a knee replacement. Some of which include; damage by arthritis or injury, medications don't help anymore, inability to perform simple activities like walking or climbing stairs, or just chronic pain. There are more than 300,000 knee replacements performed each year, and great surgical advances have been made since the first knee replacement was done back in 1968.

Procedure Details

In preparation for knee replacement surgery, patients will need to fast for 6 hours prior to their operation. After anesthesia is administered and the patient is prepped for surgery, a 6 to 8-inch incision is made over the knee, then the patella (knee cap) is be removed. This incision length is based on minimally invasive surgery. Traditional incision length could be up to 12 inches. The femur and tibia are cut to accommodate the prosthesis.

The underside of the patella is also cut to provide space for an artificial component. This is patellar resurfacing. The prosthesis is implanted onto the femur and tibia with medical bone cement. An epoxy cement or bone-growth stimulator will adhere the prosthesis to natural bone. With the bone-growth stimulator, screws are sometimes used to hold the prosthesis in place until new bone is generated. After the patella is refit to cover the joint and joint movement is assessed, the surgeon will close the incision with staples or metal clips and apply a dressing to the wound.

Risks and Side Effects

A hospital stay of 5 to 10 days should be expected. Most patients can resume work in 6 weeks to 3 months. Function of the knee will continue to improve over a 6-month period.

As with any surgery, there is potential for infection, blood clotting, nerve damage, and excessive scar tissue. Other potential risks include instability, which can be corrected by a second operation, dislocated kneecap or legs of slightly different lengths. Stiffness is a common side effect, and loosening of the prosthesis is an associated risks.

Post Operative Care

A CPM device, or continuous passive movement device, flexes the leg repeatedly to decrease postoperative pain, stiffness, bleeding, and infection, and to speed recovery. Pain medication will be administered after surgery, and an IV will remain until the patient can consume liquid and food independently. A catheter and stockings to prevent blood clots may be applied while the patient is under anesthesia, and may not be removed until after he awakens. A drainage tube will be present in the knee to remove excess fluids. Antibiotics may be administered to reduce risk of infection.

Shortly after surgery, a physical therapist will meet with the patient to advise a rehabilitation plan. Expect scarring and possible numbness in the area of the surgery. The numbness may never subside.