Total Knee Replacement: A Patient's Guide
This article reviews the benefits, risks, and alternatives to total knee replacement surgery (which is sometimes called total knee arthroplasty).
Knee replacement is a surgical procedure that decreases pain and improves the quality of life in many patients with severe arthritis of the knees. Typically patients undergo this surgery after non-operative treatments have failed to provide relief of arthritic symptoms. Non-operative treatments can include activity modification, anti-inflammatory medications, and knee joint injections.
Surgeons have performed knee replacements for over three decades generally with excellent results; most reports have ten-year success rates in excess of 90 percent.
Broadly speaking there are two types of knee replacements:
- total knee replacements and
- minimally-invasive partial knee replacements (mini knee).
Both have long “track records” and good clinical results in this country and in Europe.
Total Knee Replacement
Traditional total knee replacement involves a 7-8” incision over the knee, a hospital stay of 3-5 days, and a recovery period (during which the patient walks with a walker or cane) typically lasting from one to three months. The large majority of patients report substantial or complete relief of their arthritic symptoms once they have recovered from a total knee replacement.
Partial Knee Replacement
Partial knee replacements have been around for decades and offer excellent clinical results, just like total knee replacements. Less invasive techniques are available to insert these smaller implants but only a minority of knee replacement patients (about 10%) are good candidates for this procedure. Minimally-invasive partial knee replacement (mini knee) is the topic of another article on this website.
Patient Success Video
In the video below a patient is skiing deep powder at Bridger Bowl Montana on a total knee replacement. Please note, not all patients are able to ski and we do not recommend this activity to patients with knee replacements
Characteristics of severe arthritis of the knee
Pain is the most noticeable symptom of knee arthritis. In most patients the knee pain gradually gets worse over time but sometimes has more sudden “flares” where the symptoms get acutely severe. The pain is almost always worsened by weight-bearing and activity. In some patients the knee pain becomes severe enough to limit even routine daily activities.
Morning stiffness is present in certain types of arthritis. Patients with morning stiffness of the knee may notice some improvement in knee flexibility over the course of the day. Rheumatoid arthritis patients may experience more frequent morning stiffness than patients with osteoarthritis.
Swelling and warmth
Patients with arthritis sometimes will notice swelling and warmth of the knee. If the swelling and warmth are excessive and are associated with severe pain, inability to bend the knee, and difficulty with weight-bearing, those signs might represent an infection. Such severe symptoms require immediate medical attention. Joint infection of the knee is discussed below.
The knee joint has three “compartments” that can be involved with arthritis (see figure 1). Most patients have both symptoms and findings on X-rays that suggest involvement of two or more of these compartments; for example, pain on the lateral side (see figure 2) and beneath the kneecap (see figure 3). Patients who have arthritis in two or all three compartments, and who decide to get surgery, most often will undergo total knee replacement (see figures 4 and 5).
However, some patients have arthritis limited to one compartment of the knee, most commonly the medial side (see figure 6). When patients with one-compartment arthritis (also called “unicompartmental” arthritis) decide to get surgery, they may be candidates for minimally-invasive partial knee replacement (mini knee) (see figure 7).
Total Knee Replacement Photo Gallery
Fig. 1 Knee arthritis can affect any of the three compartments of the knee. Medial-sided knee pain, located on inside part the knee, is the most common location for arthritic pain.
Fig. 2 - Lateral knee pain affecting the outside of the knee is sometimes the result of arthritis of the knee.
Fig. 3 - Pain behind the kneecap from arthritis may occur along with arthritis elsewhere in the knee or in isolation. Isolated patellofemoral arthritis is the least common pattern of knee arthritis.
Fig. 4 - Diffuse arthritis throughout this knee from an old fracture of the tibia (shinbone) which, at that time, was treated with the two screws that are visible. This patient was later treated with a total knee replacement similar to the one shown in Fig. 5.
Fig. 5 - This patient had rheumatoid arthritis and symptoms throughout her knee resulting in the traditional total knee replacement pictured here.
Fig. 6 - This patient's arthritis was confined to the medial (inside) compartment of her knee on x-rays and her pain was localized to that part of the knee as well. She was a good candidate for minimally-invasive partial knee replacement.
Fig. 7 - Minimally-invasive partial knee replacement may be performed for either medial ("inside" of the knee) or lateral ("outside" of the knee) arthritis patterns provided the symptoms are limited to that one part of the knee. X-rays of two knee replacements are shown here. On the left is a lateral replacement and on the right is a medial replacement.