The information below was taken from our eBook, “Operations for Knee Arthritis: What To Do When All Else Has Failed To Stop Your Knee Pain.” For more information on this and our other eBooks, http://noyeskneebookseries.com/.
Knee arthritis is a potentially devastating condition that affects millions of individuals and costs billions of dollars to treat in the United States alone. In general, knee arthritis involves the breakdown or degeneration of the joint lining (called articular cartilage) on the ends of the bones in the knee joint and may also involve loss of the normal amount of space between these bones. Below is an x-ray of a knee without arthritis, which has a normal amount of joint space between the femur (thigh bone) and tibia (shin bone).
Now take a look at a knee arthritis and a complete loss of the joint space on one side – frequently called a “bone-on-bone” situation. This patient is a candidate for a unicompartmental (partial) knee replacement
Here is a photograph taken during arthroscopic surgery of a knee with normal cartilage surfaces.
Below is a photograph of a knee that has lost nearly all of the cartilage surfaces. The meniscus was torn and removed years ago.
There are many types of knee arthritis that may affect joints, the most common being osteoarthritis, post-traumatic knee arthritis, and rheumatoid.
Osteoarthritis is the most common form of knee arthritis. It is a slow, progressive disease in which the knee joint degenerates as the articular cartilage wears away. The underlying subchondral bone may become damaged. There is also a loss of the normal amount of space between the bone in the knee. This is what is usually found in middle-aged and elderly patients. It is also referred to as degenerative joint disease, or wear-and-tear knee arthritis.
Post-traumatic knee arthritis occurs after an injury to the knee, such as a fracture or tear to a ligament or meniscus. It is similar to osteoarthritis in that it involves loss of articular cartilage. However, this is more frequently found in younger patients, especially those involved in athletics.
Rheumatoid knee arthritis is an autoimmune disorder whereby the body’s immune system mistakenly attacks healthy tissue in joints and organs. It leads to chronic inflammation and may destroy the cartilage in many different joints in the body. It may begin at any age and usually occurs in both knees, along with the wrists, fingers, feet, and ankles. This discussion will focus on the other two types of knee arthritis; osteoarthritis and post-traumatic knee arthritis.
Statistics on Arthritis from the United States
- In 2005, approximately 27 million adults had osteoarthritis (in either the knees, hips, hands, or spine).
- By 2030, the number of adults with arthritis is expected to increase to 67 million, most of who will have osteoarthritis.
- Nearly 2 in 3 people who are obese may develop symptomatic knee osteoarthritis in their lifetime.
- In 2010, there were 721,443 total knee replacements performed in the U. S.
- Osteoarthritis of the knee is 1 of the 5 leading causes of disability.
- Costs from job-related osteoarthritis amount to $3.4 to $13.2 billion per year.
- 80% of patients with osteoarthritis have some amount of limitation of movement.
In terms of risk factors for the development of knee osteoarthritis, the following appear to be potentially concerning (in no ranked order)
- Genetics (family history)
- Excessive body weight (according to body mass index)
- Injury to the knee (fracture, ligament tear, meniscus tear, dislocation)
- Jobs that involve heavy manual labor, heavy lifting, repetitive knee bending
- Structural malalignment of the lower limb: bowed legs, knock-knees
- Untreated knee ligament tear (especially the anterior cruciate ligament)
- Removal of a large portion of a meniscus
- Muscle weakness, sedentary lifestyle
- Gender (women higher risk, especially after age 50)
- Age (risk increases with age)
A few other factors may play a role in increasing the risk of developing knee osteoarthritis, although their impact remains to be determined. These include diabetes, underactive thyroid, Paget’s disease, avascular necrosis, gout, other crystalline abnormalities, and hemophilia.
Conservative treatment is usually attempted first in patients who have knee arthritis in order to avoid surgery. There are many books and websites available that describe exercises, special diets, and medications (pills and injections) typically prescribed for osteoarthritis and post-traumatic arthritis.
At the Noyes Knee Institute, we have developed a specific treatment plan for knee arthritis based on our decades of experience dealing with this problem. In fact, we strongly recommend this plan for most patients, unless there is a specific indication for surgery. If, for instance, you are an athlete, have recently suffered a tear to your anterior cruciate ligament, will go through a reconstruction, and a MRI showed articular cartilage damage present, then months of conservative treatment may not be the right course of treatment.
Our conservative treatment approach is basically designed for osteoarthritis of varying degrees and consists of lifestyle changes (weight control or loss, avoidance of activities that can aggravate the knee), medications (from over-the-counter to prescription anti-inflammatory to injections), physical therapy, and supplements. Our highly experienced rehabilitation professionals design “knee-friendly” exercise programs that are effective in improving flexibility and strength, but do not aggravate knee arthritis pain.
We try to use the least amount of medication possible. In many cases of mild to moderate knee arthritis, the use of occasional over-the-counter pain and anti-inflammatory medications, along with modification of activities and weight loss, is often effective in controlling pain and swelling. Weight control is extremely important because, for every pound of weight loss, there is 4-6 pounds of reduced pressure on the knee.
We classify the amount of knee arthritis pain and limitations as mild, moderate, or severe. All patients begin with the program just described. For patients with moderate or severe knee arthritis, a knee injection using either a steroid or synthetic lubricant such as Synvisc may be offered. A knee injection is only recommended when anti-inflammatory medications, diet, and avoidance of aggravating activities are no longer effective. This treatment usually results in good relief of knee pain and swelling in three out of four patients for many months because the medication, 90% of which remains in the knee joint, decreases the inflammation in the knee better than oral medications. Patients with severe knee arthritis pain may need to consider changing their occupation if it involves aggravating activities to the knee joint. They may also need to permanently change their participation in recreation and sports.
Narcotics are not used in our clinic because they become addictive. If all conservative measures fail to alleviate pain and limitations, then surgery may be recommended.
When Conservative Treatment Fails
Unfortunately, conservative methods do not always work to resolve pain, swelling, and limitations with sports or daily activities and surgery becomes necessary. This is especially true for patients who have lost a great deal of joint lining. There are no magical medications, diets, or cures to stimulate growth of normal cartilage in the knee joint. Cartilage does not have the ability to heal or repair itself and, once injured, the process of deterioration will gradually continue.
While most people think of total knee replacement as the operation used for knee arthritis, there are in fact many other options. This is because the amount of arthritis may be mild, moderate, or severe and may involve one portion of the knee joint or several areas. At the Noyes Knee Institute, the following operations are performed:
- Arthroscopic debridement, abrasion arthroplasty
- Osteochondral autograft transfer
- Autologous chondrocyte implantation
- High tibial osteotomy
- Femoral osteotomy
- Meniscus transplantation
- Unicompartment (partial) knee replacement
- Total knee replacement
Patients who sustained knee injuries may also require other operative procedures done at the same time, such as a knee ligament reconstruction or patellar realignment.
These operations are discussed in more detail in other sections on this website under Treatment Options. As well, we have written eBooks that describe the operations and postoperative rehabilitation programs – see http://noyeskneebookseries.com/