Awful knee pain, rounding up the unusual suspects

If you have had persisting severe knee pain following an arthroscopy you might wonder why. When this happens many people will have a repeated MRI following the surgery despite the fact that one was done before the surgery. Most often the person is told that they have spontaneous osteonecrosis (bone death) of the knee or that they have an “insufficiency fracture”. These terms imply that something is wrong with your bone. Also, you would likely believe that the arthroscopy is the cause.

The aging process in the knee joint is usually very slow. Cartilage is a gristle that is as thick as an orange peel and for many of us will last a lifetime with the same material there that was there as a teenager. If you want to see cartilage, look at the end of a chicken drum stick or the joint surface of a soup bone. Only your second set of teeth, with care, has greater endurance. However, by age 75 or 80 half of us will experience knee pain due to deterioration of the joint. Millions of new cases appear each year. That process is called degenerative arthritis or osteoarthritis. This is usually a very slow process progressing over years or decades. After a long time it may cause so much interference with life that you would want to have a joint replacement.

The gradual worsening of knee osteoarthritis is different from a sudden onset of knee pain without injury. Most people will tell the doctor that their knee was quite normal before the severe pain. Despite medication and knee injections they continue to have really bad knee pain. This happens in persons who are usually over 50 years old and who are have an x-ray that is diagnosed as normal or early osteoarthritis in the knee. Most of these persons do not recall any injury or other reason that there knee should suddenly be that painful. However, when an MRI is done the interpretation is often “spontaneous osteonecrosis”. What is also often seen, but unreported, is that a “C” shape piece of gristle called the meniscus is no longer in place but extruded. To understand the interpretation of “spontaneous osteonecrosis” you should know that there are some known medical conditions that can lead to focal areas of bone death. Individuals on long term steroids, who are severely alcoholic, have sickle cell anemia, and other medical conditions can have multiple areas of loss of blood supply to small areas of bone. These folks are usually younger and the risk for this problem is well known to the person treating them. In these cases the bone is deprived of its blood supply due to that condition. What you have experienced is quite different. Here, if bone death occurs it is because a thumb nail sized piece of bone and cartilage has collapsed or separated.

Recent research has shown that when your condition occurs following arthroscopy the process may have already been silently underway prior to the surgery. Also, the number of arthroscopies done without this happening is very similar to the number of persons with silent early degenerative arthritis who spontaneously develop the problem.

Whether an insufficiency fracture follows an arthroscopy or occurs with no obvious event the good news is that if you can last through the pain for three to six months your chances are better than the flip of a coin that your pain will much less.



Spontaneous Osteonecrosis of Knee After Arthroscopy Is Not Necessarily Related to the Procedure.
Chambers C, Craig JG, Zvirbulis R, Nelson F
Am J Orthop (Belle Mead NJ). 2015 Jun


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