Arthritis in the Hip and Knee

The following notes come from Dr. Behzadi’s presentation on arthritis from February 18th, 2014.

My specialty and interest is in knee and shoulder reconstructive surgery. Arthritis is a big subject to cover. I will try to give you a broad overview.

Musculoskeletal conditions affect hundreds of people, costing an estimated $250 billion per year in the United States alone.


About 45 million Americans currently suffer from osteoarthritis (OA). Osteoarthritis is the most common of more than 100 types of arthritis.

To understand arthritis, it is helpful to look at a joint and understand how it works. A joint is where the ends of two bones meet. These bone ends are covered with a smooth material called hyaline cartilage. Cartilage cushions bones and allows your joints to move smoothly without pain. The synovium covers the joint and produces fluid that reduces friction. Ligaments connect the bones and keep your joints stable. Muscles and tendons power your joints and allow them to move.

Arthritis, simply put, is inflammation of the joints. Inflammation is our body’s normal reaction to injury. Inflammation results in visible swelling, pain, and stiffness. Chronic inflammation in an arthritic joint may cause long-standing and permanent disability.

Osteoarthritis is a kind of arthritis that affects the cartilage in the joints, causing it to break down and eventually be lost altogether. Osteoarthritis is the second most common cause of long-term disability in adults. It usually affects weight-bearing joints such as the hips, knees, and feet, followed by the fingers and spine.

Osteoarthritis affects all races equally in the United States. The prevalence of osteoarthritis rises with age, particularly after age 50. Women are more affected by it than men. By the time we are in our 60s and 70s, most of us will have some degree of arthritis.

Unlike systemic forms of arthritis (such as rheumatoid arthritis) osteoarthritis does not affect the other organs in the body. The earliest symptoms are pain in the affected joint that gets worse with prolonged use and is relieved by rest. In addition to pain, osteoarthritis sufferers experience stiffness that is commonly relieved by flexing and moving of the joints.

There is no blood test to diagnose OA; however, blood tests do rule out other forms of arthritis.

Most cases of OA have no known cause, and they are classified as primary OA. Primary OA is a byproduct of aging and simple wear and tear. Our cartilage is 80% water. As we age, the water content decreases, and the ability of the cartilage to withstand stress decreases. Also, the ligaments supporting our joints get weaker, making our joints more prone to injury.

By contrast, secondary OA is caused by another disease or condition. Obesity, trauma, and previous surgery are common causes of secondary OA. Abnormal joints at birth, gout, diabetes, and various hormone disorders can also be a factor.

Our focus of discussion is OA. However, it is important to understand that there are many different kinds of arthritis. In general, you can divide them into two broad categories: osteoarthritis, which has to do with wear and tear and contributing factors, such as obesity and trauma, etc., and inflammatory arthritis, an autoimmune condition where the body essentially attacks itself, including rheumatoid arthritis, lupus and psoriasis.

Treatment of Osteoarthritis

When you see your doctor, he/she will take a thorough history, perform a physical exam, obtain X-rays and potentially MRI and other scans, and a blood test to obtain an accurate diagnosis.

The goal of treatment for OA is to relieve pain, increase motion, and improve strength. Conservative treatment may include rest, exercise, weight reduction, and physical therapy, along with use of medications and injections. Surgical treatment is varied, we will touch on few techniques.

There are a variety of medications that can provide relief from the effects of arthritis. Over the counter pharmaceuticals like aspirin, ibuprofen, and naproxen can be used to control pain and inflammation. Tylenol simply controls pain, but not inflammation. When over the counter medicines are no longer effective, your doctor may prescribe COX-2 inhibitors such as Celebrex. Anti-inflammatories do have associated risks when taken over prolonged periods of time and can damage your kidney, liver and GI tract. Celebrex generally causes less gastrointestinal problems.

In cases where oral medications are ineffective, injections can be considered. Cortisone and hyaluronic acid (a cartilage extract) may provide significant pain relief.

Vitamin supplements may offer a benefit. Some studies have suggested that optimal intake of anti-oxidants A, C, D, and E may help prevent OA. However, the evidence comes from lab studies rather than clinical trials, and as such, there is no proof that vitamin supplements help.

Glucosamine and Chondroitin SO4 are popular dietary supplements. While some positive results have been reported, the treatment affects are probably exaggerated. I usually tell my patients to stop taking it if they have felt no change in symptoms after a 2-month trial.

Alternative therapy options for OA are in great in number, but their effectiveness is often unclear. Alternative medicine may help you take an active role in your health care, ease your symptoms, especially pain, stiffness, stress, anxiety, and depression, improving your outlook, attitude, and the quality of your life.

Joint protection in the form of walkers, canes, crutches, and braces may relieve stress and strain on arthritic joints.

Gentle exercise may be very beneficial for OA. Done in moderation, it strengthens the muscles around the joints preventing stiffness. It also helps reduce weight and promotes endurance. The goal is to do enough to maintain mobility and strength, but not to aggravate and or flare up your arthritic joints. It is important to find out what your physical limit is and not to push yourself over that threshold.

In some cases surgery may be warranted. There are several surgical options for treatment of OA, including arthroscopy, osteotomy, cartilage restoration procedures, joint replacement, and newer technologies with use of navigation and robotics.

Arthroscopy is one of the least invasive procedures. The surgeon looks inside the joint through small incisions (portals) with an arthroscope and removes the partially damaged cartilage. The concept here is to remove loose bodies and fragments of dead cartilage in the joint that cause the inflammation. This “clean up” procedure often helps with pain relief, but it is an unreliable method for treating OA. The underlying condition does not change.

Other procedures that are done arthroscopically include micro-fracture chondroplasty, during which abrasion and drilling of the exposed bone stimulates a healing response, creating a form of “scar-cartilage”. This tissue is not as good as normal cartilage, but is certainly better than exposed bone. These procedures are mostly indicated for smaller and more localized lesions.

Osteotomy is an operation that involves realignment of the bones around a joint, with the goal of transferring weight to the healthier part of the joint. It was popular in the 70s and 80s and is still being done now. However, it is an operation that has lost favor with joint surgeons because it does not provide good long-term results.

Several operations are intended for more localized forms of arthritis, and these are referred to as “articular cartilage restoration” surgeries. These are indicated for smaller and more localized defects. Two of the most common ones are OATs procedures and ACI or cartilage transplant operations. In an OATs procedure, a plug of healthy bone and cartilage is transferred from a non-weight bearing area in your knee to a defect in the weight bearing area.

In ACI, cartilage transplantation, and it various forms, cartilage cells are harvested and grown in the lab, then implanted into a defect in the joint, much like fixing a pothole in the road. Again, these operations are for smaller and more localized defects.

Joint Replacement

Joint replacement is considered the final solution for advanced arthritis of the knee, hip, and shoulder. Improved ambulation and decreased pain are the most desirable outcomes for these procedures. Good to excellent long-term results can be expected for more than 90% of the patients who have total joint replacements.

With knee replacement, bone cuts are made. The “end surface” of the both the femur and the tibia is replaced with metal, a plastic liner is inserted between the femur and the tibia, and the patella is resurfaced with plastic.

With hip replacement, the hip socket is replaced with a metal cup, and a plastic liner is inserted into the cup. A metal stem is inserted into the femur and a metal head is attached, helping it to articulate with the plastic liner.

Other forms of joint replacement are also available, especially in the knee. In some cases where OA is in its early to mid stages, and only one out of the three compartments of the knee is compromised, a partial knee replacement can be considered. In fact, we can isolate the compartments in the knee and provide resurfacing only to the part that is worn out.

When you look at the big picture of OA, from a surgical perspective, we have a variety of procedures that we offer as this condition evolves over time. We may scope a knee with a small defect (and consider the cartilage restoration procedures first). We may do a partial knee replacement for someone who has isolated disease in one compartment, and do a total knee replacement for advanced disease.

Over the last two decades there have been significant advances in joint replacement surgery, both in materials and design and surgical technique. Unfortunately, the evolution of any industry involves successes and failures, and despite extensive testing prior to release, these products are not truly tested until they have been on the market for a while.

I want to cautiously put a plug in for a new technology that has recently become available here in SRMC, involving use of robotics in knee replacement surgery. Partial knee replacements have generally not been in favor as much as total knee replacements. The primary reason is that it is a more difficult operation to perform with conventional instruments and it is harder to get the femoral and tibial prosthesis to match each other. The result can be early failure and wear.

MAKOplasty® is a technique in which a robotic tool assists the surgeon with the surgery. It is a tool that gives the surgeon a tremendous amount of information and helps with precise positioning of the prosthesis and ligament balancing. During the procedure, the bone is precisely milled, and implants are applied. The key to this technique is real-time “virtual visualization” of bone resection and implant placement. You can actually see in detail during the surgery how these implants interact with each other throughout ROM, allowing fine tuning of implant position, prior to bone resection. Basically, we can match the two prosthetic components much better than we could have ever done before.

In summary, osteoarthritis affects more than 40 million Americans, and you may be one of them. Accurate diagnosis is important. It is also important for you to understand as much as you can about this condition. Many treatment options are available. Spend time with your doctor to understand the benefits and limitations of these options and choose the right treatment for you.