Artificial knees last longer, work better and can be installed with smaller incisions.
HEALTH Over half a million total knee replacements are performed annually to relieve pain from severe degenerative disease such as arthritis. But this is by no means the preferred treatment option. Nonsurgical techniques must first be exhausted. With each step, forces equal to several times a person's body weight are transmitted through the knee. Hence, the first option includes activity modification, regular exercise and weight loss.  Be mindful that rehabilitation following knee replacement includes exercise. So patients should certainly not be quick to consider surgery as a means to avoid exercise. Any combination of soft knee braces, shoe modifications, dietary supplements, a cane, and steroid injections may be recommended by a rheumatologist or orthopedic specialist.
After exhausting nonsurgical treatment options, some patients may continue to experience pain performing even the simplest of activities. At this point surgery is considered. Expect an incision, three- to five-day hospital stay and months of therapy. Recuperation varies among individuals based on such factors as patient age, weight, and cause of knee degeneration.
Minimally invasive surgery (MIS) for knee joint replacement requires an incision of three to six inches. Traditional knee replacement includes an 8- to 12-inch cut. MIS knee replacement surgery therefore includes less tissue trauma, allowing the surgeon to work between the fibers of the quadriceps and preventing incision through the tendon. This may decrease recovery time and produce less scar tissue. 
New techniques for opening the knee may be more important than the length of the incision. Some techniques are "quadriceps-sparing" because they protect the quadriceps tendon and muscle in the front of the thigh. Other techniques called "mid-vastus" and "sub-vastus" make small incisions in the muscle but are also less invasive. 
MIS knee replacement surgery is not as common in the United States as it is in Europe and other countries. Accurate implant positioning is more of a concern with MIS. Additional research is required to compare the long-range benefits of MIS versus traditional surgery.