Biology Of Arthritis

Arthritis is more than 100 types of joint diseases that affect 53 million adults and 300,000 children in the U.S.

The Biology Of Arthritis

Arthritis is a disorder of any joint in your body that leads to symptoms such as inflammation, pain, and limited function. Most arthritis occurs in the knee and joint, hip joint, followed by the ankle and shoulder joint. In addition, arthritis of the fingers and base of the thumb is quite common. It’s estimated over 50 million people suffer from osteoarthritis in the United States to the point of requiring regular medications, typically anti-inflammatory medications. Arthritis is the most common chronic illness in the United States.

Treating Arthritis Early

Treating Arthritis as early as possible is not a new concept. In 1989, a study published in The Lancet emphasized the importance of starting treatment early. The main difference between discussions of early arthritis treatment 15 to 20 years ago and today are the treatments are available for aggressive treatment..

Arthritis Facts

Arthritis Prevalence

  • By conservative estimates, about 54 million adults have doctor-diagnosed arthritis.
  • Almost 300,000 babies and children have arthritis or a rheumatic condition.
  • The most common type of arthritis is osteoarthritis, which affects an estimated 31 million Americans.
  • Number of people expected to have doctor-diagnosed arthritis by the year 2040: more than 78 million.

The stages of osteoarthritis in the joint can be broken into five specific areas.

  1. Chondrocyte or cartilage cell proliferation, and then cell death.  In normal cartilage there is a strict regulation of articular cartilage turnover.  There is a delicate balance between the synthesis of new articular cartilage and its degradation.  Think of this as the treads on a tire.  Imagine a tire that, as you wear it down, has the ability to regenerate the treads.  However if one continuously goes on long trips, the wear of the tire exceeds its ability to create new treads.  In the development of osteoarthritis, the cartilage cells respond to injury and damage by attempting to produce more cartilage cells.  This occurs because the surface of the articular cartilage due to trauma of day to day living creates fissures and begins to crack and break up, which stimulates the cartilage cells to produce more cells and attempt to repair the damage.
  2. Synthetic activity, where this attempt at repair results in increased anabolic activity.
  3. Degradation is where the cartilage cells cannot keep up with the damage and enzymes are released that break down the collagen fibers in the articular cartilage.  Collagen is a protein that holds the articular cartilage together.  New degrading enzymes are being discovered on a regular basis.
  4. Cartilage cells actually undergo a change and become more like fibroblasts.  Fibroblasts are a cells that are specific for producing collagen to try to, again, repair the damage.
  5. Formation of osteophytes, where the body produces more bone on the edges of the joint, create more stability in the joint and also cause it to have a loss of motion.  All this is an end stage attempt to avoid the progression of osteoarthritis.

During the development of osteoarthritis, the synovium, or the lining of the joint, is inflamed which causes the joint to swell, feel warm and hot, and the other underlying bone is often inflamed.  This can be seen on an MRI scan where the bone has markedly increased blood flow.  Think of it as being sunburned where the bone is swollen, red, and causes pain. This same process occurs in all the joints that are undergoing osteoarthritis, whether it is the hip, knee, shoulder, ankle, elbow, wrist, or fingers.

Treatment

The treatment for osteoarthritis, as recommended by the American Academy of Orthopedic Surgeons, consists of weight loss with the goal of your body mass index being 25 or less.  The body mass index is determined by your height and your weight.  Modifications of this can be made depending on your exact body habitus.  Gentle exercise, avoiding the pounding of running, is generally recommended.  The best aerobic exercise is that in a swimming pool or bicycle riding, where one can increase heart rate without increasing stress on the joints.  Gentle weight lifting can be helpful to maintain muscle strength and flexibility.  Gentle stretching of the joint can sometimes be helpful.  Chiropractic care, physical therapy with various modalities, such as heat and cold treatments, the use of laser treatments, acupuncture can be helpful.  The use of various braces to support the joint during activities can be helpful.  Often medications, especially non-steroidal anti-inflammatory drugs such as Motrin or Naproxen or Advil or prescribed NSAIDs are helpful.  The use of analgesics for pain relief, such as Tylenol or sometimes even narcotics to avoid surgery can be used.  Steroid injections into a joint can temporarily be helpful but have the side effect of increasing the degradation of the cartilage, so in the long run they actually accelerate osteoarthritis and most orthopedic surgeons would avoid injecting a joint more than once with steroids.  Various hyaluronic acid injections can be utilized.  However, four prospective randomized studies have shown no efficacy in the use of hyaluronic acids to treat osteoarthritis of the knee at six month follow up.  The American Academy of Orthopedic Surgeons strongly recommends against the use of these injections.  However, despite a lack of any scientific evidence of efficacy, the use of these injections is quite common, and is a $400 million a year business.  This demonstrates the real void in non-operative and operative treatment.  The American Academy of Orthopedic Surgeons (AAOS) strongly is against any arthroscopic lavage of a joint for osteoarthritis.  Prospective randomized studies have shown that washing a knee joint arthroscopically with normal saline and shaving the cartilage has no long-term efficacy, and in fact, has been shown to increase the development of osteoarthritis in a joint.