Knee Osteoarthritis

Background

The knee is an important joint for weight-bearing activity.  The knees pain free function is crucial in allowing us to move freely.  Unfortunately as a weight bearing joint that is stressed almost constantly throughout our lives, knees are prone to cartilage wear and degeneration resulting in osteoarthritis.  When cartilage deteriorates leaving exposed bone inside of the knee joint, the knee responds by increasing release of inflammatory signals within the knee.  The lining of the knee joint responds to these signals by becoming inflamed and often times produces an abundance of watery lubrication for the knee.  This can cause swelling and increased pain in the knee.  The bones of the knee may also respond to the chronic inflammation with extra bone growth called osteophytes or bone spurs, this can lead to further inflammation and pain.

Diagnosis

When someone has a history of increasing pain in the knee it is important to  evaluate the knee by physical exam as well as imaging studies (such as X-rays and in some cases MRI).  We take time to fully examine the knee and look for range-of-motion restrictions, areas of tenderness around the knee, and the stability of all of the ligaments of the knee.  We use X-rays to evaluate the alignment of your knee joint, look for fractures, and to assess the overall health of your knee.  While not directly visualized, x-rays can also give us insight into the overall health of the cartilage in the knee.  On occasion we may also require an MRI to evaluate the cartilage surfaces in the knee.  If the space between the bones of the knee is getting very small, it can indicate that there is significant cartilage wear occurring in the knee.   There are three compartments that are evaluated for cartilage wear in the knee.  These are the, medial (inside), lateral (outside), and patellofemoral (under your kneecap).  A person can develop osteoarthritis in one, two, or all three compartments of the knee.

Treatment

In the early arthritic knee, treatment may initially consist of activity modification (ie. don’t do things that irritate the knee), anti-inflammatory treatment with over the counter medications such as acetaminophen, ibuprofen, or naproxen, or a combination of both.  As osteoarthritis worsens, injection of a more potent antiinflammatory such as a corticosteroid directly into the knee may be indicated.  This allows the antiinflammatory medication to be focused into the the knee and can provide very good and long lasting pain relief.  Other medications such as viscosupplementation  injections may also be offered in an attempt to alleviate the pain and discomfort caused by the osteoarthritis.  These options may in some cases provide long lasting relief and in other cases may not alleviate the symptoms of osteoarthritis.  

When conservative measures are no longer providing adequate pain relief,  a surgical options may be explored.  For an isolated  single compartment arthritis and good overall health of the knee, your surgeon may recommend a partial or uni-compartmental knee replacement.   This is a surgical procedure to replace only the joint surfaces in the single affected compartment of the knee.  If two or more compartments are arthritic a total knee replacement is indicated.  In this case, all three compartments are replaced at the same time.

Regardless of which treatment option is pursued, we want you to have a knee with full range-of-motion and good neuromuscular control.  Occasionally you may be asked to go to physical therapy  prior to any surgical intervention.  Therapy prior to surgery can help address strength and mobility issues that may prevent you from achieving your goals for full activity after surgery. In addition you can become comfortable with the types of exercises you will be required to perform in order to fully rehabilitate your knee after surgery.

Rehabilitation

Knee replacement surgery (total or partial) rehabilitation is a demanding process.  It is important to regain full extension of your knee in order for you to walk with a normal gait after surgery.  We will continue to stress the importance of gaining full extension and working hard to prevent stiffness in the knee.  In addition to range-of-motion, you will also work on strength and gait training.  Being engaged and participating in your rehabilitation will help ensure that you have the best opportunity to achieve a more normal and fully functional knee joint.