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. 

NUMBNESS

It's normal to have some numbness around the front and outer side of the knees following TKR.  This is due to nerve injury during surgery which can result in a decrease or loss in sensation either temporarily or permanently.  Feeling of numbness, tingling or burning sensation are indications of nerve injury or damage.

A nerve is an enclosed, cable-like bundle much like an electrical cable with lots of fine wires.  Each nerve is a cord like structure that contains many axons (nerve cells).  These axons are often referred to as fibres.  Within a nerve, each axon is surrounded by a layer of connective tissue called the endoneurium.  The axons are bundled together into groups called fascicles, and each fascicle is wrapped in a layer of connective tissue called the perineurium.  Finally, the entire nerve is wrapped in a layer of connective tissue called the epineurium (see picture of nerves anatomy below obtained from internet).

Anatomy of Nerves

Nerves are fragile and can be damaged by pressure, stretching or cutting.  Injury to a nerve can stop signals to and from the brain, causing muscles not to work properly and a loss of feeling in the injured area.

There is a nerve called saphenous that comes down the inside of the thigh and on into the calf.  It has a small branch called the infrapatellar branch that goes across the front of the knee and provides sensory input from the skin in that area.  This nerve branch is in the path of the incision so it is necessary to cut through it to gain exposure to the knee during TKR surgery. 

When a nerve is cut and the ends are sutured together, the axons within seek to grow out to their opposite numbers and join up again.  In this arduous task, some might succeed but a majority of them don't and they end up lost and just die off.  During TKR surgery, the nerves are roughly approximated as the wound is sutured without much accuracy.  So whether you have any return of sensation depends on your luck.  Some people are fortunate enough to have complete return of sensation while others may only have some return.  And there are some who are unfortunate enough to have no return of sensation at all so the numbness becomes permanent.

There are several major blood vessels and nerves around the knee but they are rarely injured during TKR.  However, a minority of people may experience more severe symptoms from nerve injury post TKR including feeling of ankle weakness when lifting up the foot, dragging toe when trying to walk or numbness on top of the foot.

It is common to have a feeling of pins and needles during the recovery process. While this can be uncomfortable, it will pass and is a sign of recovery.  I have observed that it is quite common to have reduction in the numb spot which then becomes permanent. However, there is a small minority of people who have complete return of sensation.  Personally, I don't think I will be one of those lucky ones as after 17 months, I still have the numbness.  Although numbness can cause a strange sensation, the most important thing is that it does not impair our overall function. 

As for me, it's not an issue living with the numbness as it does not bother me nor does it affect my function.  If I can live with the stiffness, this is nothing compared to it.  In fact, I consider both of them a very small price to pay for my two pain free knees.

DEPRESSION POST TKR

Depression may be described as feeling sad, blue, unhappy, miserable or down in the dumps.  Most of us may have experienced this before for short periods particularly after certain incidents or a major surgery.

It is quite common for people to have feelings of depression after TKR which is a major surgery.  This usually happens during early recovery.  Symptoms experienced includes crying, anxiety, fear etc. Some people may even feel a sense of regret of having done the surgery or they may be convinced that things are not going to get any better.  These are typical negative thoughts which actually contribute to the depression.

Some people may even have depressive feelings before surgery. This may be due to the shock of finding out that we need TKR. So we either get into a denial stage and procrastinate or we decide to do the surgery. Even if we do decide to do TKR, we may feel very anxious with the waiting period.

From my TKR forums, I have come across many people saying that they felt depressed during early recovery.  Some would just burst out crying non stop and some just felt down in the dumps.  Personally, I did experienced it for a brief period.  Mostly, I felt depressed about the negative comments from certain family members due to their lack of understanding.  I also felt lonely when my husband and children either left to work or school and all the down time made me miserable.

There are a variety of factors that contribute to such depressive feelings which includes:-

1.     Temporary loss of mobility and feeling confined to the house
2.     Discomfort from pain, swelling and stiffness
3.     Loss of privacy
4.     Loss of independence as we need to rely on others for help
5.    Side effects of medication which may cause some chemical, emotional and physiological 
       changes in the body
6.    Loss of confidence in normal daily activities
7.    Fear of falling down, fear of things not going to improve further etc.
8.    Feeling anxious about how long recovery is going to take
9.    Negative comments from family members or friends due to their lack of understanding
10.  Lack of sleep
11.  Regret doing the surgery
12   Loneliness
13.  Self pity

These feelings of depression during early recovery will usually fade out as we begin to be more active and return to regular activities.

To prevent or minimise depression during recovery, I would like to suggest the following:-

1.   Have adequate knowledge about TKR so that we can be better prepared.
2.   Learn from other people's experience by joining a TKR forum.
3.   Keep a positive mindset.
4.   Reward our self with something that we like even for a small milestone. 
5.   Try to get out of the house even for a while as soon as we are able to as this will lift our mood. 
6.   Educate family members about TKR so they can be more understanding and encouraging.
7.   Family members should provide necessary support and show more care and concern.
8.   Be aware of recovery time so that we do not have unrealistic expectations.