“Is Knee Arthritis just a normal part of the aging process?” I am asked this question countless times a day. It is not. However, knee arthritis is alarmingly common and a growing national concern.

Consider this recent data published by the National Institutes of Health:
1. In people over the age of 45, the incidence of knee arthritis is 15-20%
2. In the US, we are projected to perform 1.5 million total knee replacements in 2020 and 3.5 million in 2030
3. The cost borne by society for total joint replacements alone in 2030 (the vast majority are total knee replacements) will be in excess of 100 billion dollars (which was 1% of the gross domestic product (GDP) in 2007!!).

Here is data from a recent study presented at the American Academy of Orthopedic Surgeons:
1. At present, almost 5% of the US population over the age of 50 is living with a total knee replacement.
2. Approximately 7-10% of the US population will undergo knee resurfacing at some point in their lives.

These are truly staggering numbers. Clearly, knee arthritis poses a tremendous health and socioeconomic burden on our society. In 2012, we do not have a cure for knee arthritis. In my previous blog, I discussed the single most powerful treatment we have for arthritis: weight modification. This powerful intervention is based on the fact that knee arthritis is typically osteoarthritis, a mechanical phenomenon where a portion of the joint is overloaded (typically the inside or medial portion of the joint is overloaded, producing a pressure point where cartilage and bone breaks down). As such, decreasing load across the arthritic joint can slow the progression of disease. The 3 primary means of unloading the joint are:
1. weight loss (every pound on our body is 5-7 pounds on your knee)
2. strengthening the muscles around the knee through exercise and physical therapy (so that the muscles take load off the joint)
3. limiting high loading activities (such as running, jumping, and cutting sports)

We do not have any disease modifying drugs for osteoarthritis at present. However, pills such as ibuprofen and other anti-inflammatory medications, and shots, can help treat the symptoms of arthritis by decreasing pain and swelling. These treatments do not result in structural changes to the joint or “cure” the arthritis.

The optimal surgical treatment in 2012 is to remove the involved joint surfaces and provide a new metallic and plastic joint surface. The most common procedure of this type is total knee replacement. This treatment has improved the lives of millions of Americans by restoring mobility and eliminating pain. In addition, the surgery is durable and the new joint can last for up to 30 years (though not all do). However, the surgery is not perfect. Indeed, total knee replacement is great operation for pain, but typically patients can expect a decrease in their level of sports performance after the procedure. The recovery can be arduous and may require 3 months of rehabilitation prior to return to work.

An emerging alternative to total knee replacement is partial knee resurfacing, where only the overloaded region of the knee is resurfaced. This “partial knee replacement” allows for a much quicker recovery and importantly, typically allows patients to restore or enhance their athletic performance.

I will provide a more comprehensive review of the rationale for knee resurfacing versus knee replacement in my next blog.

About Andrew D. Pearle, MD

Andrew D. Pearle, MD is a board-certified Orthopedic Surgeon at the Hospital for Special Surgery, specializing in Sports Medicine, Arthroscopy and Robotic Surgery.

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