Osteoarthritis of the knee can cause severe pain and quality of life issues. Knee pain due to arthritis can be disabling when it has progressed to its most severe form. Until recently, a knee replacement has been our go to option. A big issue arises in the young, and middle aged person with arthritis. Knee replacements can wear out, and are not be a great option to implant into a 35 or 40 year old. Knee joint distraction may be an interesting alternative to explore.

Osteoarthritis is a degenerative condition which affects the articular cartilage of the knee. Over time the cartilage wears out and becomes very thin. In some regions of the knee it might be completely absent… thus giving rise to the term bone on bone arthritis.

Notice the bones touching one another.

Osteoarthritis can occur due to aging, genetics or as the end result of an injury. In people who had an ACL tear or a meniscus tear which led to a partial menisectomy osteoarthritis of the knee will occur. Often times in our 30’s or 40’s. Very few good options exist to manage severe osteoarthritis of the knee in this age group. Joint replacements wear out, especially if you are very active after the surgery. Stem cells, fat cells and PRP injections might help you manage the pain for a while but they have not been shown to reverse the cartilage loss or arthritic change.

What is Knee Distraction surgery?

Knee distraction surgery involves placing an apparatus or external fixator on your leg. We place pins into your femur or thigh bone and into your tibia or shin bone. We then connect special cylinders or rods to the pins and use them to distract your knee. The amount we distract is just a few millimeters. We leave that apparatus or external fixator on your leg for nearly 2 months, then remove it and start your therapy. At the time of the surgery, most surgeons are also injecting stems cells from bone marrow or fat at the same time that they place the apparatus on your leg.

Can Knee Distraction Cure Arthritis?

The knee distraction technique appears to result in some cartilage regrowth. The space between the bone reappears on X-rays within a few months of surgery. MRI analysis appears to show regrowth of cartilage. Is this curing osteoarthritis? No.. but for now it seems to be delaying the need for a knee replacement for a long time. Many recent scientific papers have shown that cartilage will regrow in the knee and that the bones are no longer touching one another. Further study will be needed to see how long this new cartilage will last. Most researchers believe that the cartilage growth comes from the stem cells injected into the knee. But stem cells implanted into a knee with distraction do not lead to cartilage growth… so the distraction must be causing other changes inside the knee conducive to cartilage growth.

This paper discusses knee joint distraction and the favorable response most participants in the study realized. The authors found that cartilage regenerated in many knees.

This most recent paper in one of our leading journal also regards knee distraction as an alternative worth exploring in the young or middle age patient with severe osteoarthritis and a poor quality of life.

This is obviously a very interesting development in the management of an arthritic knee in young and middle aged active people. Being able to put off a knee replacement for 10-15 years or more has many potential advantages. For one, you have your natural knee. You can participate in sports or other activities. You have not burned any bridges… if this procedure fails you can still have a knee replacement. You put off the potentially significant risks of a knee replacement such as infection, stiffness, insufficient pain relief, etc. The external fixator has risks too. You can have infections where the pins poke through your skin. You can fracture the tibia or femur because of stress fractures which can start at the holes left when the fixator comes off. But these are low risk events when compared to issues which arise when a knee replacement goes badly.

As with any relatively new procedure further research is needed. The technique needs to be refined… the proper stem cells or other substances to inject at the time of surgery need to be determined too. Stay tuned though…