Knee Replacement

When the articular cartilage of your knee is damaged beyond repair, most often due to osteoarthritis (or degenerative joint disease), knee replacement surgery seeks to remove the damaged portion of the knee and replace it with an artificial component. Your knee joint has three parts (or compartments):

• The medial compartment – the inner joint where the femur meets the tibia
• The lateral compartment – the outer joint where the femur meets the tibia
• The patellofemoral joint – where the kneecap meets the femur

f only one compartment of your knee is damaged, you may be a good candidate for partial knee replacement (or unicompartmental knee replacement), in which only one compartment of the knee joint surface is removed and replaced. Partial knee replacement is less invasive than total knee replacement and offers the following advantages:

• Faster recovery time
• Less pain following surgery
• Less blood loss

Partial knee replacement can also be significantly less expensive than total knee replacement as, in many cases, it can be performed in an outpatient surgery center, avoiding the expense of a hospital stay.

In cases of severe osteoarthritis, there is often too much damage to the articular cartilage for a partial knee replacement and a total knee replacement is the operation of choice. In a total knee replacement, all three compartments of the knee are resurfaced to restore mobility and alleviate pain. A total knee replacement (or total knee arthroplasty) involves four main steps:

• Preparation – The damaged cartilage, as well as a small amount of the bone, is removed from the ends of the femur and tibia and the new surfaces are shaped to fit the designated implants.
• Positioning – Metal implants are positioned in place of the removed bone and cartilage to recreate the joint surface. The implants are then cemented in place.
• Patellar Resurfacing – The damaged underside of the kneecap is removed and replaced with a plastic implant. This step my be omitted, depending on the individual patient’s case.
• Spacing – A plastic spacer is inserted between the newly resurfaced ends of the femur and tibia, creating a smooth surface for gliding (acting in place of cartilage for the artificial knee).

Gender-specific knee replacement refers to implants crafted specifically to accommodate the female knee. For years, the same knee replacement implants were used for men and women. However, in the early 2000s, knee replacement implants were developed specifically for the female knee to take into account the facts that:

• Women tend to have smaller, narrower knees than men.
• Women have more of an angle between their hip and knee than men.
• Women’s kneecaps are positioned slightly differently than men’s.
• The prominence on the front of the femur is less pronounced in women than in men.

Choosing the correct knee replacement implant for your specific case ensures that your implant will fit better, function better, and last longer.

• Most patients will stay 3-4 days in the hospital and then begin physical therapy (either with a physical therapist coming to their home or in outpatient physical therapy sessions). Some patients will return to routine activities such as driving within 2-3 weeks.
• After recovering from knee replacement, you can expect to live a normal lifestyle, including activities like walking, hiking, biking, hunting, and fishing.  According to the American Academy of Orthopaedic Surgeons (AAOS), more than 90% of total knee replacement patients experience a significant reduction in pain as well as a vastly increased ability to perform daily activities.
• Low impact activities are the key to the long-term success of your knee implant, so you will want to avoid high impact activities like running, which would put increased stress on the metal and plastic implants. Your goal after knee replacement should be to live a “knee-friendly” low-impact lifestyle and keep the muscles surrounding the joint strong to maximize the effectiveness and longevity of your artificial knee.