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Insider Arthritis Tips May 2009 Newsletter
May 15, 2009

Table of Contents

I have pain on the outside of the knee… what could it be?

Wei's World

"Choose a job you love, and you will never have to work a day in your life." -- Confucius, Philosopher


I have pain on the outside of the knee… what could it be?

Knee pain is very common in an arthritis practice. The location of the knee pain often provides a clue to diagnosis.

Pain located on the outside part of the knee (the side where the small toe is) is a common complaint with many potential causes.

The first is osteoarthritis. Although less common in the outside compartment than in the medial (inside compartment- big toe side), it is still a frequent problem. Pain is felt on the lateral (outside)) part of the knee generally with weight-bearing. The knee tends to stiffen if the patient sits for any length of time. There may be swelling due to fluid accumulation.

Pain at night is also a frequent complaint. The treatment is the same for osteoarthritis involving the inside part of the knee. Anti-inflammatory medicines, corticosteroid injections, viscosupplement injections, physical therapy, and weight loss (if indicated) will help. Unloader bracing (braces that take the weight off the outside part of the knee) are useful. Stem cell procedures also may be beneficial. If the joint space is completely gone (“bone on bone”), joint replacement is advised.

Another problem that may be coincident with osteoarthritis is a tear of the lateral meniscus. The lateral meniscus is a tough piece of fibrocartilage that helps to cushion the outside compartment of the knee. It acts as a stabilizer with weight-bearing and with rotation movements of the leg. A torn lateral meniscus will cause pain with weight-bearing. There may be swelling due to fluid accumulation. In addition, patients may complain of locking or a sensation of “give-way” in the knee. Torn lateral menisci often require arthroscopic intervention.

Another cause of pain on the outside part of the knee is a strain of the lateral collateral ligament. This is a stabilizing ligament that protects the lateral compartment. Often seen with athletic injuries, lateral collateral ligament strain is treated with ice, rest, physical therapy, and anti-inflammatory medicines. More recently, injections of PRP (platelet-rich plasma) using ultrasound and tenotomy technique have been found to be helpful in accelerating healing.

An injury to the peroneal nerve where it crosses the head of the fibula (the smaller of the two lower leg bones) can also cause pain on the outside of the knee. Generally, history and physical exam can elicit the diagnosis. Peroneal nerve entrapment can be a complication of surgery involving the leg. We have seen it in women who have undergone knee replacement using replacements that were designed for men. When the replacement device is a bit too big, it can irritate the peroneal nerve leading to entrapment. If the nerve is trapped, needle hydrodissection using ultrasound guidance works wonders to free up the nerve.

Iliotibial band (ITB) syndrome is a condition where the iliotibial band, a thick band of fibrous tissue that runs down the outside of the leg, becomes irritated and inflamed. The iliotibial band begins at the hip and runs down to the outer side of the tibia (shin bone) just below the knee joint. The band provides stability to the outside of the knee joint. ITB irritation occurs over the outside of the knee joint, at the lateral epicondyle--the end of the femur (thigh) bone. The iliotibial band crosses bone and muscle at this point. Repetitive motion at this site leads to inflammation and pain with movement.

Usually the pain worsens with continued movement, and gets better with rest.

People who suddenly increase their level of activity, such as runners who abruptly increase their mileage, can develop iliotibial band syndrome. Other people who are prone to get this condition are people who have leg length differences or are bow-legged.

Treatment of iliotibial band syndrome consists of stretching, limiting excessive training, and resting. Non-steroidal anti-inflammatory drugs (NSAIDS) may be useful. Physical therapy and corticosteroid injections have been used as well. PRP (platelet-rich plasma) combined with tenotomy (“peppering” the iliotibial band with small holes using a tiny needle) is often curative.

Surgery is rarely an option.

Wei's World

My wife, Judy, recently took our son, Benji, to Maine to visit Bowdoin College. He had recently been accepted to Bowdoin and Judy wanted to make sure Benji felt comfortable with his decision to attend.

As many of you know Benji has had arthritis since the age of 10. So it’s been a little hard for me to come to grips with the fact that he’ll be a college freshman this fall.

It seems like just yesterday he was a 10-year old boy…with horrible arthritis.

Now you might think that because I’m a rheumatologist, it would have been easier for me to deal with it. It was actually the opposite. While I was close to the condition because it was my specialty, when it came to my son, I was a dad. I felt frustrated and powerless… plus, knowing too much got me thinking about all the horrible complications of the disease.

After consulting an orthopedic surgeon and three pediatric rheumatologists and battling his condition for a year and a half, Benji was getting no better.

I decided to call Dr. Tom Lehman, a medical school classmate, and chief of pediatric rheumatology at the New York-Presbyterian Hospital in New York City.

Dr Lehman immediately saw how poorly Benji was doing and started him on several different medications including biologic therapy. Benji has been in remission now for six years.

I am constantly reminded of Benji’s story when I talk to patients about participating in research trials. The biologic medicine he was put on that put him into remission was developed through clinical research. Which brings me to this key point…

The most common question patients ask when approached about participating in research trials is, “What about side effects?”

I make sure patients are made aware of what is known about an investigational drug. But we don’t know everything. That was the same situation I was in with Benji. Even though I had been part of the early research on biologic therapy, I didn’t know what the long-term side effects of this treatment could be. And I still don’t. Nobody does. But I also know that without biologic therapy Benji would have ended up being crippled… or even worse.

Judy and I had to trust Dr. Lehman’s judgment. I look at my son now and see a vibrant, healthy, bright kid who has a lot going for him… even though he is very messy!

Every decision in life requires a careful evaluation of pros and cons. On one side you consider the potential risks. On the other you weigh the potential benefits.

But every morning, I give thanks for the opportunity to do clinical research in the hopes that it will help others like Benji.

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Insider Arthritis Tips A monthly ezine on arthritis written by a board-certified rheumatologist with tons of excellent and useful information for anyone interested in arthritis

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