OA STILL EXIST AFTER TKR?

This question has been on my mind for some time now and I have been searching for an answer.  Some medical sources says that OA is no longer present after TKR based on the common understanding that it is not an actual disease but a wear and tear condition.  However, there has been a recent study by Stanford suggesting that OA is a degenerative disease resulting from inflammatory process, not just  wear and tear (see link below).  Perhaps this explains why more and more younger people are diagnosed with OA. This development offers hope that someday this condition may be preventable. Therefore, I remain puzzled whether OA still exist after TKR but I do hope to find a definite answer someday. Whatever it is, the end result is still joint damage.

http://www.med.stanford.edu/ism/2011/november/osteoarthritis.html

Meanwhile, assuming that OA is no longer present, why do I still have the stiffness after prolonged sitting, standing and walking which feels the same as before TKR?  Apparently, this is due to the damage caused by OA.  Frankly, I have been quite ignorant of the damages that can be caused by OA in the long run.  I thought that after TKR, apart from the pain, all the stiffness, aches and tenderness would be gone and range of motion would be restored.  However, after 18 months now, I still have the same range of motion and stiffness. And some areas around the knees and legs still have the same tenderness.  The most logical explanation that I can think of is that OA has caused some permanent damage to my body.  Only recently I found out from some joint replacement medical professionals that the stiffness we still experience after recovery from TKR is due to the damage from OA.  

When our cartilage deteriorates, the bones rub together when we walk thereby causing a lot of pain and damage on the joint surface.  Eventually, spurs will be formed due to the damage of the joints.  These bony spurs might look tiny but they can cause a lot of pain.  It can also get dislodged somewhere in the body.  I know of someone whose spur from the knee joint surface got dislodged in her thigh muscle.  She suffered a lot of pain and eventually, got it removed through surgery. The spur actually caused some torn muscles.

When the surface of our joints are damaged, there is imbalance in the joint.  To describe it in another way (a very good analogy given by a medical professional), just imagine a camping tent. A tent is held by poles (bones) and guy ropes (muscles and ligaments) and pegs in the ground (their attachment on the bones).  If the surface upon which they depend on stability becomes out of balance, then the whole structure will lean over.  When this happens in our knee joints, the imbalance will cause deformities such as bow legs (lateral side) or knock knees (medial side).  And this state of collapse causes the muscles and ligaments to become slack and tight.  Eventually, the muscles and ligaments become inflamed, sore, tight and painful.  The function of ligaments is to attach bones to bones and give strength and stability to the knee as the knee has very little stability.  Ligaments are strong tough bands that are not particularly flexible (see picture below obtained from internet).  Once stretched, they tend to stay stretched and if stretched too far, they snap.  Therefore, the damage done to muscles and ligaments as the arthritic process develops carries over post TKR.  So this explains why we still have stiffness after TKR. 



Normal knee anatomy

Now what about all the limping and bad posture when we walk due to our arthritic knees?  This can cause problems to our body in the long run particularly back and hip problems.  OA can also cause Baker Cyst and Posterior Tibial Tendon Dysfunction which affects the ankles and feet.

During TKR surgery, we have trauma caused to soft tissues and major muscles. This will cause severe inflammation on the entire area of the knee joint.  The muscles and ligaments will be sore, tight and inflamed and we will have rubber band sensations, aches and pains, tense and tight episodes, reaction to weather change etc. So all these sensations are caused by the trauma to the soft tissues, muscles and ligaments which should settle down or reduce after a period of time.

While TKR gives us a new functioning knee and pain relief but it does not remove the damage caused by OA.  This is something that we really need to consider if we decide to delay surgery.  I think the point now is not how long we can tolerate the pain but rather how much damage we will cause to our body if we choose to delay the surgery. 

Despite all these information, I don't think people are going to run to do TKR.  TKR is a major challenge for most people.  There are many people who would rather suffer or be wheelchair bound than do TKR.  The fear is too great and I think it is largely due to a lack of courage and understanding about OA and TKR.  Of course, there is also the concern of doctors tyring to delay TKR as long as possible due to age factor and revisions required.  I thought that when I did my bilateral TKR at age 50, I was rather young.  But I am finding that more and more younger people who suffer from severe arthritis are willing to do TKR in order to gain a better quality of life. 

So even though I still have the stiffness, it is something that I can live with and it does help if I do a lot of stretching. I am grateful that I still have a reasonable range of motion that does not impair my overall function.  And I am most grateful that I did my bilateral TKR as it has enabled me to lead an active life with pain free knees.